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Wodtke P, Grashei M, Schilling F. Quo Vadis Hyperpolarized 13C MRI? Z Med Phys 2023:S0939-3889(23)00120-4. [PMID: 38160135 DOI: 10.1016/j.zemedi.2023.10.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 10/16/2023] [Accepted: 10/20/2023] [Indexed: 01/03/2024]
Abstract
Over the last two decades, hyperpolarized 13C MRI has gained significance in both preclinical and clinical studies, hereby relying on technologies like PHIP-SAH (ParaHydrogen-Induced Polarization-Side Arm Hydrogenation), SABRE (Signal Amplification by Reversible Exchange), and dDNP (dissolution Dynamic Nuclear Polarization), with dDNP being applied in humans. A clinical dDNP polarizer has enabled studies across 24 sites, despite challenges like high cost and slow polarization. Parahydrogen-based techniques like SABRE and PHIP offer faster, more cost-efficient alternatives but require molecule-specific optimization. The focus has been on imaging metabolism of hyperpolarized probes, which requires long T1, high polarization and rapid contrast generation. Efforts to establish novel probes, improve acquisition techniques and enhance data analysis methods including artificial intelligence are ongoing. Potential clinical value of hyperpolarized 13C MRI was demonstrated primarily for treatment response assessment in oncology, but also in cardiology, nephrology, hepatology and CNS characterization. In this review on biomedical hyperpolarized 13C MRI, we summarize important and recent advances in polarization techniques, probe development, acquisition and analysis methods as well as clinical trials. Starting from those we try to sketch a trajectory where the field of biomedical hyperpolarized 13C MRI might go.
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Affiliation(s)
- Pascal Wodtke
- Department of Nuclear Medicine, TUM School of Medicine and Health, Klinikum rechts der Isar of Technical University of Munich, 81675 Munich, Germany; Department of Radiology, University of Cambridge, Cambridge CB2 0QQ, United Kingdom; Cancer Research UK Cambridge Centre, University of Cambridge, Cambridge UK
| | - Martin Grashei
- Department of Nuclear Medicine, TUM School of Medicine and Health, Klinikum rechts der Isar of Technical University of Munich, 81675 Munich, Germany
| | - Franz Schilling
- Department of Nuclear Medicine, TUM School of Medicine and Health, Klinikum rechts der Isar of Technical University of Munich, 81675 Munich, Germany; Munich Institute of Biomedical Engineering, Technical University of Munich, 85748 Garching, Germany; German Cancer Consortium (DKTK), Partner Site Munich and German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, Heidelberg 69120, Germany.
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2
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Jezewski AJ, Ristow LC, Krysan DJ. Carbon Dioxide Potentiates Flucytosine Susceptibility in Cryptococcus neoformans. Microbiol Spectr 2023; 11:e0478322. [PMID: 36719209 PMCID: PMC10101005 DOI: 10.1128/spectrum.04783-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 01/11/2023] [Indexed: 02/01/2023] Open
Abstract
Cryptococcal meningoencephalitis remains a global health threat with limited treatment options. Currently, the most effective treatment regimens are based on a combination therapy of flucytosine with either amphotericin B or fluconazole. Slow but steady progress is being made toward universal access to flucytosine-based therapies. The broadening access to flucytosine combination therapies will be accompanied by the need for microbiological methods that reliably determine strain susceptibility. This is especially true considering that flucytosine susceptibility can vary widely across clinical isolates. Identifying culture conditions that best represent the host environment are likely optimal and may even be required for accurately determining in vivo flucytosine susceptibility. Here, we report that culture conditions incorporating host-like concentrations of carbon dioxide (CO2) potentiated flucytosine susceptibilities across clinical isolates (10 of 11) that exhibited a range of MIC values under ambient growth conditions (2 to 8 μg/mL) by standard Clinical and Laboratory Standards Institute susceptibility testing. CO2 induced a dose-dependent increase in flucytosine susceptibility between 2- and 8-fold over standard conditions. The CO2-dependent increase in flucytosine susceptibility did not correspond to an increase in fluorouracil susceptibility, indicating a central role for flucytosine uptake through the cytosine permease in the presence of host-like CO2 concentrations. Indeed, the expression of the cytosine permease gene (FCY2) was induced 18- to 60-fold in the mouse lung environment. Therefore, the activity of flucytosine is likely to be very dependent upon host environment and may not be well represented by standard in vitro susceptibility testing. IMPORTANCE Cryptococcus neoformans causes life-threatening infections of the brain. The most effective treatment regimens are based on flucytosine-based combination therapy, which has led to increasingly successful broadening of access to flucytosine globally. Wider use of flucytosine-based therapies for cryptococcal infections will require the ability to reliably determine clinical isolate susceptibilities. We showed that host-like carbon dioxide stress affected flucytosine susceptibility, and this likely occurred through flucytosine uptake. We further showed that the gene encoding the permease, FCY2, and that is responsible for flucytosine uptake was strongly induced during cryptococcal infection. Our data provide insights into the distinctions between the activity of flucytosine in the host environment and during in vitro susceptibility testing.
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Affiliation(s)
- Andrew J. Jezewski
- Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Laura C. Ristow
- Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
| | - Damian J. Krysan
- Department of Pediatrics, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
- Department of Microbiology and Immunology, Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA
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Stewart NJ, Sato T, Takeda N, Hirata H, Matsumoto S. Hyperpolarized 13C Magnetic Resonance Imaging as a Tool for Imaging Tissue Redox State, Oxidative Stress, Inflammation, and Cellular Metabolism. Antioxid Redox Signal 2022; 36:81-94. [PMID: 34218688 PMCID: PMC8792501 DOI: 10.1089/ars.2021.0139] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Significance: Magnetic resonance imaging (MRI) with hyperpolarized (HP) 13C-labeled redox-sensitive metabolic tracers can provide noninvasive functional imaging biomarkers, reflecting tissue redox state, oxidative stress, and inflammation, among others. The capability to use endogenous metabolites as 13C-enriched imaging tracers without structural modification makes HP 13C MRI a promising tool to evaluate redox state in patients with various diseases. Recent Advances: Recent studies have demonstrated the feasibility of in vivo metabolic imaging of 13C-labeled tracers polarized by parahydrogen-induced polarization techniques, which offer a cost-effective alternative to the more widely used dissolution dynamic nuclear polarization-based hyperpolarizers. Critical Issues: Although the fluxes of many metabolic pathways reflect the change in tissue redox state, they are not functionally specific. In the present review, we summarize recent challenges in the development of specific 13C metabolic tracers for biomarkers of redox state, including that for detecting reactive oxygen species. Future Directions: Applications of HP 13C metabolic MRI to evaluate redox state have only just begun to be investigated. The possibility to gain a comprehensive understanding of the correlations between tissue redox potential and metabolism under different pathological conditions by using HP 13C MRI is promoting its interest in the clinical arena, along with its noninvasive biomarkers to evaluate the extent of disease and treatment response.
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Affiliation(s)
- Neil J Stewart
- Division of Bioengineering & Bioinformatics, Graduate School of Information Science & Technology, Hokkaido University, Sapporo, Japan.,POLARIS, Imaging Sciences, Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, United Kingdom
| | - Tatsuyuki Sato
- Division of Cardiology and Metabolism Center for Molecular Medicine, Jichi Medical University, Shimotsuke-shi, Japan.,Department of Cardiovascular Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.,Japan Society for the Promotion of Science, Tokyo, Japan
| | - Norihiko Takeda
- Division of Cardiology and Metabolism Center for Molecular Medicine, Jichi Medical University, Shimotsuke-shi, Japan
| | - Hiroshi Hirata
- Division of Bioengineering & Bioinformatics, Graduate School of Information Science & Technology, Hokkaido University, Sapporo, Japan
| | - Shingo Matsumoto
- Division of Bioengineering & Bioinformatics, Graduate School of Information Science & Technology, Hokkaido University, Sapporo, Japan
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Nykänen AI, Mariscal A, Duong A, Estrada C, Ali A, Hough O, Sage A, Chao BT, Chen M, Gokhale H, Shan H, Bai X, Zehong G, Yeung J, Waddell T, Martinu T, Juvet S, Cypel M, Liu M, Davies JE, Keshavjee S. Engineered mesenchymal stromal cell therapy during human lung ex vivo lung perfusion is compromised by acidic lung microenvironment. Mol Ther Methods Clin Dev 2021; 23:184-197. [PMID: 34703841 PMCID: PMC8516994 DOI: 10.1016/j.omtm.2021.05.018] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Accepted: 05/07/2021] [Indexed: 11/29/2022]
Abstract
Ex vivo lung perfusion (EVLP) is an excellent platform to apply novel therapeutics, such as gene and cell therapies, before lung transplantation. We investigated the concept of human donor lung engineering during EVLP by combining gene and cell therapies. Premodified cryopreserved mesenchymal stromal cells with augmented anti-inflammatory interleukin-10 production (MSCIL-10) were administered during EVLP to human lungs that had various degrees of underlying lung injury. Cryopreserved MSCIL-10 had excellent viability, and they immediately and efficiently elevated perfusate and lung tissue IL-10 levels during EVLP. However, MSCIL-10 function was compromised by the poor metabolic conditions present in the most damaged lungs. Similarly, exposing cultured MSCIL-10 to poor metabolic, and especially acidic, conditions decreased their IL-10 production. In conclusion, we found that "off-the-shelf" MSCIL-10 therapy of human lungs during EVLP is safe and feasible, and results in rapid IL-10 elevation, and that the acidic target-tissue microenvironment may compromise the efficacy of cell-based therapies.
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Affiliation(s)
- Antti I Nykänen
- Latner Thoracic Surgery Research Laboratories, Toronto General Hospital Research Institute, University Health Network and University of Toronto, 101 College Street, Toronto, ON M5G 1L7, Canada
| | - Andrea Mariscal
- Latner Thoracic Surgery Research Laboratories, Toronto General Hospital Research Institute, University Health Network and University of Toronto, 101 College Street, Toronto, ON M5G 1L7, Canada
| | - Allen Duong
- Latner Thoracic Surgery Research Laboratories, Toronto General Hospital Research Institute, University Health Network and University of Toronto, 101 College Street, Toronto, ON M5G 1L7, Canada
| | - Catalina Estrada
- Tissue Regeneration Therapeutics, 790 Bay Street, Toronto, ON M5G 1N8, Canada
| | - Aadil Ali
- Latner Thoracic Surgery Research Laboratories, Toronto General Hospital Research Institute, University Health Network and University of Toronto, 101 College Street, Toronto, ON M5G 1L7, Canada
| | - Olivia Hough
- Latner Thoracic Surgery Research Laboratories, Toronto General Hospital Research Institute, University Health Network and University of Toronto, 101 College Street, Toronto, ON M5G 1L7, Canada
| | - Andrew Sage
- Latner Thoracic Surgery Research Laboratories, Toronto General Hospital Research Institute, University Health Network and University of Toronto, 101 College Street, Toronto, ON M5G 1L7, Canada
| | - Bonnie T Chao
- Latner Thoracic Surgery Research Laboratories, Toronto General Hospital Research Institute, University Health Network and University of Toronto, 101 College Street, Toronto, ON M5G 1L7, Canada
| | - Manyin Chen
- Latner Thoracic Surgery Research Laboratories, Toronto General Hospital Research Institute, University Health Network and University of Toronto, 101 College Street, Toronto, ON M5G 1L7, Canada
| | - Hemant Gokhale
- Latner Thoracic Surgery Research Laboratories, Toronto General Hospital Research Institute, University Health Network and University of Toronto, 101 College Street, Toronto, ON M5G 1L7, Canada
| | - Hongchao Shan
- Latner Thoracic Surgery Research Laboratories, Toronto General Hospital Research Institute, University Health Network and University of Toronto, 101 College Street, Toronto, ON M5G 1L7, Canada
| | - Xiaohui Bai
- Latner Thoracic Surgery Research Laboratories, Toronto General Hospital Research Institute, University Health Network and University of Toronto, 101 College Street, Toronto, ON M5G 1L7, Canada
| | - Guan Zehong
- Latner Thoracic Surgery Research Laboratories, Toronto General Hospital Research Institute, University Health Network and University of Toronto, 101 College Street, Toronto, ON M5G 1L7, Canada
| | - Jonathan Yeung
- Latner Thoracic Surgery Research Laboratories, Toronto General Hospital Research Institute, University Health Network and University of Toronto, 101 College Street, Toronto, ON M5G 1L7, Canada
| | - Tom Waddell
- Latner Thoracic Surgery Research Laboratories, Toronto General Hospital Research Institute, University Health Network and University of Toronto, 101 College Street, Toronto, ON M5G 1L7, Canada
| | - Tereza Martinu
- Latner Thoracic Surgery Research Laboratories, Toronto General Hospital Research Institute, University Health Network and University of Toronto, 101 College Street, Toronto, ON M5G 1L7, Canada
| | - Stephen Juvet
- Latner Thoracic Surgery Research Laboratories, Toronto General Hospital Research Institute, University Health Network and University of Toronto, 101 College Street, Toronto, ON M5G 1L7, Canada
| | - Marcelo Cypel
- Latner Thoracic Surgery Research Laboratories, Toronto General Hospital Research Institute, University Health Network and University of Toronto, 101 College Street, Toronto, ON M5G 1L7, Canada
| | - Mingyao Liu
- Latner Thoracic Surgery Research Laboratories, Toronto General Hospital Research Institute, University Health Network and University of Toronto, 101 College Street, Toronto, ON M5G 1L7, Canada
| | - John E Davies
- Institute of Biomedical Engineering, University of Toronto, 164 College St, Toronto, ON M5S 3G9, Canada
| | - Shaf Keshavjee
- Latner Thoracic Surgery Research Laboratories, Toronto General Hospital Research Institute, University Health Network and University of Toronto, 101 College Street, Toronto, ON M5G 1L7, Canada
- Institute of Biomedical Engineering, University of Toronto, 164 College St, Toronto, ON M5S 3G9, Canada
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Bøgh N, Hansen ESS, Mariager CØ, Bertelsen LB, Ringgaard S, Laustsen C. Cardiac pH-Imaging With Hyperpolarized MRI. Front Cardiovasc Med 2020; 7:603674. [PMID: 33244471 PMCID: PMC7683793 DOI: 10.3389/fcvm.2020.603674] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2020] [Accepted: 10/16/2020] [Indexed: 11/13/2022] Open
Abstract
Regardless of the importance of acid-base disturbances in cardiac disease, there are currently no methods for clinical detection of pH in the heart. Several magnetic resonance imaging techniques hold translational promise and may enable in-vivo mapping of pH. We provide a brief overview of these emerging techniques. A particular focus is on the promising advance of magnetic resonance spectroscopy and imaging with hyperpolarized 13C-subtrates as biomarkers of myocardial pH. Hyperpolarization allows quantification of key metabolic substrates and their metabolites. Hereby, pH-sensitive reactions can be probed to provide a measure of acid-base alterations. To date, the most used substrates are [1-13C]pyruvate and 13C-labeled bicarbonate; however, others have been suggested. In cardiovascular medicine, hyperpolarized magnetic resonance spectroscopy has been used to probe acid-base disturbances following pharmacological stress, ischemia and heart failure in animals. In addition to pH-estimation, the technique can quantify fluxes such as the pivotal conversion of pyruvate to lactate via lactate dehydrogenase. This capability, a good safety profile and the fact that the technique is employable in clinical scanners have led to recent translation in early clinical trials. Thus, magnetic resonance spectroscopy and imaging may provide clinical pH-imaging in the near future.
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Affiliation(s)
- Nikolaj Bøgh
- The MR Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | | | | | - Lotte Bonde Bertelsen
- The MR Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Steffen Ringgaard
- The MR Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
| | - Christoffer Laustsen
- The MR Research Center, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
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6
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Arshad U, Pertinez H, Box H, Tatham L, Rajoli RKR, Curley P, Neary M, Sharp J, Liptrott NJ, Valentijn A, David C, Rannard SP, O’Neill PM, Aljayyoussi G, Pennington SH, Ward SA, Hill A, Back DJ, Khoo SH, Bray PG, Biagini GA, Owen A. Prioritization of Anti-SARS-Cov-2 Drug Repurposing Opportunities Based on Plasma and Target Site Concentrations Derived from their Established Human Pharmacokinetics. Clin Pharmacol Ther 2020; 108:775-790. [PMID: 32438446 PMCID: PMC7280633 DOI: 10.1002/cpt.1909] [Citation(s) in RCA: 95] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 05/18/2020] [Indexed: 12/13/2022]
Abstract
There is a rapidly expanding literature on the in vitro antiviral activity of drugs that may be repurposed for therapy or chemoprophylaxis against severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2). However, this has not been accompanied by a comprehensive evaluation of the target plasma and lung concentrations of these drugs following approved dosing in humans. Accordingly, concentration 90% (EC90 ) values recalculated from in vitro anti-SARS-CoV-2 activity data was expressed as a ratio to the achievable maximum plasma concentration (Cmax ) at an approved dose in humans (Cmax /EC90 ratio). Only 14 of the 56 analyzed drugs achieved a Cmax /EC90 ratio above 1. A more in-depth assessment demonstrated that only nitazoxanide, nelfinavir, tipranavir (ritonavir-boosted), and sulfadoxine achieved plasma concentrations above their reported anti-SARS-CoV-2 activity across their entire approved dosing interval. An unbound lung to plasma tissue partition coefficient (Kp Ulung ) was also simulated to derive a lung Cmax /half-maximal effective concentration (EC50 ) as a better indicator of potential human efficacy. Hydroxychloroquine, chloroquine, mefloquine, atazanavir (ritonavir-boosted), tipranavir (ritonavir-boosted), ivermectin, azithromycin, and lopinavir (ritonavir-boosted) were all predicted to achieve lung concentrations over 10-fold higher than their reported EC50 . Nitazoxanide and sulfadoxine also exceeded their reported EC50 by 7.8-fold and 1.5-fold in lung, respectively. This analysis may be used to select potential candidates for further clinical testing, while deprioritizing compounds unlikely to attain target concentrations for antiviral activity. Future studies should focus on EC90 values and discuss findings in the context of achievable exposures in humans, especially within target compartments, such as the lungs, in order to maximize the potential for success of proposed human clinical trials.
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Affiliation(s)
- Usman Arshad
- Department of Molecular and Clinical PharmacologyMaterials Innovation FactoryUniversity of LiverpoolLiverpoolUK
| | - Henry Pertinez
- Department of Molecular and Clinical PharmacologyMaterials Innovation FactoryUniversity of LiverpoolLiverpoolUK
| | - Helen Box
- Department of Molecular and Clinical PharmacologyMaterials Innovation FactoryUniversity of LiverpoolLiverpoolUK
| | - Lee Tatham
- Department of Molecular and Clinical PharmacologyMaterials Innovation FactoryUniversity of LiverpoolLiverpoolUK
| | - Rajith K. R. Rajoli
- Department of Molecular and Clinical PharmacologyMaterials Innovation FactoryUniversity of LiverpoolLiverpoolUK
| | - Paul Curley
- Department of Molecular and Clinical PharmacologyMaterials Innovation FactoryUniversity of LiverpoolLiverpoolUK
| | - Megan Neary
- Department of Molecular and Clinical PharmacologyMaterials Innovation FactoryUniversity of LiverpoolLiverpoolUK
| | - Joanne Sharp
- Department of Molecular and Clinical PharmacologyMaterials Innovation FactoryUniversity of LiverpoolLiverpoolUK
| | - Neill J. Liptrott
- Department of Molecular and Clinical PharmacologyMaterials Innovation FactoryUniversity of LiverpoolLiverpoolUK
| | - Anthony Valentijn
- Department of Molecular and Clinical PharmacologyMaterials Innovation FactoryUniversity of LiverpoolLiverpoolUK
| | - Christopher David
- Department of Molecular and Clinical PharmacologyMaterials Innovation FactoryUniversity of LiverpoolLiverpoolUK
| | | | | | - Ghaith Aljayyoussi
- Department of Tropical Disease BiologyLiverpool School of Tropical MedicineCentre for Drugs and DiagnosticsLiverpoolUK
| | - Shaun H. Pennington
- Department of Tropical Disease BiologyLiverpool School of Tropical MedicineCentre for Drugs and DiagnosticsLiverpoolUK
| | - Stephen A. Ward
- Department of Tropical Disease BiologyLiverpool School of Tropical MedicineCentre for Drugs and DiagnosticsLiverpoolUK
| | - Andrew Hill
- Department of Molecular and Clinical PharmacologyMaterials Innovation FactoryUniversity of LiverpoolLiverpoolUK
| | - David J. Back
- Department of Molecular and Clinical PharmacologyMaterials Innovation FactoryUniversity of LiverpoolLiverpoolUK
| | - Saye H. Khoo
- Department of Molecular and Clinical PharmacologyMaterials Innovation FactoryUniversity of LiverpoolLiverpoolUK
| | | | - Giancarlo A. Biagini
- Department of Tropical Disease BiologyLiverpool School of Tropical MedicineCentre for Drugs and DiagnosticsLiverpoolUK
| | - Andrew Owen
- Department of Molecular and Clinical PharmacologyMaterials Innovation FactoryUniversity of LiverpoolLiverpoolUK
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7
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Spatiotemporal pH Heterogeneity as a Promoter of Cancer Progression and Therapeutic Resistance. Cancers (Basel) 2019; 11:cancers11071026. [PMID: 31330859 PMCID: PMC6678451 DOI: 10.3390/cancers11071026] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2019] [Revised: 07/17/2019] [Accepted: 07/18/2019] [Indexed: 12/15/2022] Open
Abstract
Dysregulation of pH in solid tumors is a hallmark of cancer. In recent years, the role of altered pH heterogeneity in space, between benign and aggressive tissues, between individual cancer cells, and between subcellular compartments, has been steadily elucidated. Changes in temporal pH-related processes on both fast and slow time scales, including altered kinetics of bicarbonate-CO2 exchange and its effects on pH buffering and gradual, progressive changes driven by changes in metabolism, are further implicated in phenotypic changes observed in cancers. These discoveries have been driven by advances in imaging technologies. This review provides an overview of intra- and extracellular pH alterations in time and space reflected in cancer cells, as well as the available technology to study pH spatiotemporal heterogeneity.
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8
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Korenchan DE, Gordon JW, Subramaniam S, Sriram R, Baligand C, VanCriekinge M, Bok R, Vigneron DB, Wilson DM, Larson PEZ, Kurhanewicz J, Flavell RR. Using bidirectional chemical exchange for improved hyperpolarized [ 13 C]bicarbonate pH imaging. Magn Reson Med 2019; 82:959-972. [PMID: 31050049 DOI: 10.1002/mrm.27780] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 03/29/2019] [Accepted: 04/01/2019] [Indexed: 12/18/2022]
Abstract
PURPOSE Rapid chemical exchange can affect SNR and pH measurement accuracy for hyperpolarized pH imaging with [13 C]bicarbonate. The purpose of this work was to investigate chemical exchange effects on hyperpolarized imaging sequences to identify optimal sequence parameters for high SNR and pH accuracy. METHODS Simulations were performed under varying rates of bicarbonate-CO2 chemical exchange to analyze exchange effects on pH quantification accuracy and SNR under different sampling schemes. Four pulse sequences, including 1 new technique, a multiple-excitation 2D EPI (multi-EPI) sequence, were compared in phantoms using hyperpolarized [13 C]bicarbonate, varying parameters such as tip angles, repetition time, order of metabolite excitation, and refocusing pulse design. In vivo hyperpolarized bicarbonate-CO2 exchange measurements were made in transgenic murine prostate tumors to select in vivo imaging parameters. RESULTS Modeling of bicarbonate-CO2 exchange identified a multiple-excitation scheme for increasing CO2 SNR by up to a factor of 2.7. When implemented in phantom imaging experiments, these sampling schemes were confirmed to yield high pH accuracy and SNR gains. Based on measured bicarbonate-CO2 exchange in vivo, a 47% CO2 SNR gain is predicted. CONCLUSION The novel multi-EPI pulse sequence can boost CO2 imaging signal in hyperpolarized 13 C bicarbonate imaging while introducing minimal pH bias, helping to surmount a major hurdle in hyperpolarized pH imaging.
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Affiliation(s)
- David E Korenchan
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California
| | - Jeremy W Gordon
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California
| | - Sukumar Subramaniam
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California
| | - Renuka Sriram
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California
| | - Celine Baligand
- Molecular Imaging Research Center, French Alternative Energies and Atomic Energy Commission Fontenay-aux-Roses, France
| | - Mark VanCriekinge
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California
| | - Robert Bok
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California
| | - Daniel B Vigneron
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California.,UC Berkeley, UCSF Graduate Program in Bioengineering, University of California, University of California, San Francisco, Berkeley, California
| | - David M Wilson
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California
| | - Peder E Z Larson
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California.,UC Berkeley, UCSF Graduate Program in Bioengineering, University of California, University of California, San Francisco, Berkeley, California
| | - John Kurhanewicz
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California.,UC Berkeley, UCSF Graduate Program in Bioengineering, University of California, University of California, San Francisco, Berkeley, California
| | - Robert R Flavell
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, California
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9
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Steinhauser J, Wespi P, Kwiatkowski G, Kozerke S. Production of highly polarized [1- 13 C]acetate by rapid decarboxylation of [2- 13 C]pyruvate - application to hyperpolarized cardiac spectroscopy and imaging. Magn Reson Med 2019; 82:1140-1149. [PMID: 31045272 DOI: 10.1002/mrm.27782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Revised: 03/27/2019] [Accepted: 04/03/2019] [Indexed: 11/10/2022]
Abstract
PURPOSE The objective of the present work was to develop and implement an efficient approach to hyperpolarize [1-13 C]acetate and apply it to in vivo cardiac spectroscopy and imaging. METHODS Rapid hydrogen peroxide induced decarboxylation was used to convert hyperpolarized [2-13 C]pyruvate into highly polarized [1-13 C]acetate employing an additional step following rapid dissolution of [2-13 C]pyruvate in a home-built multi-sample dissolution dynamic nuclear polarization system. Phantom dissolution experiments were conducted to determine optimal parameters of the decarboxylation reaction, retaining polarization and T1 of [1-13 C]acetate. In vivo feasibility of detecting [1-13 C]acetate metabolism is demonstrated using slice-selective spectroscopy and multi-echo imaging of [1-13 C]acetate and [1-13 C]acetylcarnitine in the healthy rat heart. RESULTS The first in vivo signal was observed ~23 s after dissolution. At the corresponding time point in the phantom experiments, 97.9 ± 0.4% of [2-13 C]pyruvate were converted into [1-13 C]acetate by the decarboxylation reaction. T1 and polarization of [1-13 C]acetate was determined to be 29.7 ± 1.9% and a 47.7 ± 0.5 s. Polarization levels of [2-13 C]pyruvate and [1-13 C]acetate were not significantly different after transfer to the scanner. In vivo, [1-13 C]acetate and [1-13 C]acetylcarnitine could be detected using spectroscopy and imaging. CONCLUSION Decarboxylation of hyperpolarized [2-13 C]pyruvate enables the efficient production of highly polarized [1-13 C]acetate that is applicable to study short-chain fatty acid metabolism in the in vivo heart.
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Affiliation(s)
- Jonas Steinhauser
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
| | - Patrick Wespi
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
| | - Grzegorz Kwiatkowski
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
| | - Sebastian Kozerke
- Institute for Biomedical Engineering, University and ETH Zurich, Zurich, Switzerland
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10
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Hundshammer C, Grashei M, Greiner A, Glaser SJ, Schilling F. pH Dependence of T 1 for 13 C-Labelled Small Molecules Commonly Used for Hyperpolarized Magnetic Resonance Imaging. Chemphyschem 2019; 20:798-802. [PMID: 30790394 DOI: 10.1002/cphc.201801098] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2018] [Revised: 02/07/2019] [Indexed: 01/18/2023]
Abstract
Hyperpolarization is a method to enhance the nuclear magnetic resonance signal by up to five orders of magnitude. However, the hyperpolarized (HP) state is transient and decays with the spin-lattice relaxation time (T1 ), which is on the order of a few tens of seconds. Here, we analyzed the pH-dependence of T1 for commonly used HP 13 C-labelled small molecules such as acetate, alanine, fumarate, lactate, pyruvate, urea and zymonic acid. For instance, the T1 of HP pyruvate is about 2.5 fold smaller at acidic pH (25 s, pH 1.7, B0 =1 T) compared to pH close to physiological conditions (66 s, pH 7.3, B0 =1 T). Our data shows that increasing hydronium ion concentrations shorten the T1 of protonated carboxylic acids of most of the analyzed molecules except lactate. Furthermore it suggests that intermolecular hydrogen bonding at low pH can contribute to this T1 shortening. In addition, enhanced proton exchange and chemical reactions at the pKa appear to be detrimental for the HP-state.
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Affiliation(s)
- Christian Hundshammer
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, Munich.,Department of Chemistry, Technical University of Munich, Lichtenbergstraße 4, 85748, Garching.,Graduate School of Bioengineering, Technical University of Munich, Boltzmannstr. 11, 85748, Garching
| | - Martin Grashei
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, Munich
| | - Alexandra Greiner
- Department of Chemistry, Technical University of Munich, Lichtenbergstraße 4, 85748, Garching
| | - Steffen J Glaser
- Department of Chemistry, Technical University of Munich, Lichtenbergstraße 4, 85748, Garching
| | - Franz Schilling
- Department of Nuclear Medicine, Klinikum rechts der Isar, Technical University of Munich, Ismaninger Str. 22, 81675, Munich
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11
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Kurhanewicz J, Vigneron DB, Ardenkjaer-Larsen JH, Bankson JA, Brindle K, Cunningham CH, Gallagher FA, Keshari KR, Kjaer A, Laustsen C, Mankoff DA, Merritt ME, Nelson SJ, Pauly JM, Lee P, Ronen S, Tyler DJ, Rajan SS, Spielman DM, Wald L, Zhang X, Malloy CR, Rizi R. Hyperpolarized 13C MRI: Path to Clinical Translation in Oncology. Neoplasia 2019; 21:1-16. [PMID: 30472500 PMCID: PMC6260457 DOI: 10.1016/j.neo.2018.09.006] [Citation(s) in RCA: 280] [Impact Index Per Article: 56.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Revised: 09/27/2018] [Accepted: 09/27/2018] [Indexed: 12/22/2022]
Abstract
This white paper discusses prospects for advancing hyperpolarization technology to better understand cancer metabolism, identify current obstacles to HP (hyperpolarized) 13C magnetic resonance imaging's (MRI's) widespread clinical use, and provide recommendations for overcoming them. Since the publication of the first NIH white paper on hyperpolarized 13C MRI in 2011, preclinical studies involving [1-13C]pyruvate as well a number of other 13C labeled metabolic substrates have demonstrated this technology's capacity to provide unique metabolic information. A dose-ranging study of HP [1-13C]pyruvate in patients with prostate cancer established safety and feasibility of this technique. Additional studies are ongoing in prostate, brain, breast, liver, cervical, and ovarian cancer. Technology for generating and delivering hyperpolarized agents has evolved, and new MR data acquisition sequences and improved MRI hardware have been developed. It will be important to continue investigation and development of existing and new probes in animal models. Improved polarization technology, efficient radiofrequency coils, and reliable pulse sequences are all important objectives to enable exploration of the technology in healthy control subjects and patient populations. It will be critical to determine how HP 13C MRI might fill existing needs in current clinical research and practice, and complement existing metabolic imaging modalities. Financial sponsorship and integration of academia, industry, and government efforts will be important factors in translating the technology for clinical research in oncology. This white paper is intended to provide recommendations with this goal in mind.
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Affiliation(s)
- John Kurhanewicz
- Department of Radiology and Biomedical Imaging, University of California San Francisco, San Francisco, CA, USA.
| | - Daniel B Vigneron
- Department of Radiology and Biomedical Imaging, University of California at San Francisco, San Francisco, CA, USA
| | | | - James A Bankson
- Department of Imaging Physics, MD Anderson Medical Center, Houston, TX, USA
| | - Kevin Brindle
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | | | | | - Kayvan R Keshari
- Department of Radiology, Memorial Sloan Kettering Cancer Center, NY, New York, USA
| | - Andreas Kjaer
- Department of Clinical Physiology, Nuclear Medicine & PET and Cluster for Molecular Imaging, Rigshospitalet and University of Copenhagen, Denmark
| | | | - David A Mankoff
- Department of Radiology, University of Pennsylvania, PA, USA
| | - Matthew E Merritt
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL, USA
| | - Sarah J Nelson
- Department of Radiology and Biomedical Imaging, University of California at San Francisco, San Francisco, CA, USA
| | - John M Pauly
- Department of Electric Engineering, Stanford University, USA
| | - Philips Lee
- Functional Metabolism Group, Singapore Biomedical Consortium, Agency for Science, Technology and Research, Singapore
| | - Sabrina Ronen
- Department of Radiology and Biomedical Imaging, University of California at San Francisco, San Francisco, CA, USA
| | - Damian J Tyler
- Department of Biomedical Science, University of Oxford, Oxford, UK
| | - Sunder S Rajan
- Center for Devices and Radiological Health (CDRH), FDA, White Oak, MD, USA
| | - Daniel M Spielman
- Departments of Radiology and Electric Engineering, Stanford University, USA
| | - Lawrence Wald
- Department of Radiology, Harvard Medical School, Boston, MA, USA
| | - Xiaoliang Zhang
- Department of Radiology and Biomedical Imaging, University of California at San Francisco, San Francisco, CA, USA
| | - Craig R Malloy
- Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, USA
| | - Rahim Rizi
- Department of Radiology, University of Pennsylvania, PA, USA
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12
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Mechanistic Basis of pH-Dependent 5-Flucytosine Resistance in Aspergillus fumigatus. Antimicrob Agents Chemother 2018; 62:AAC.02593-17. [PMID: 29610197 DOI: 10.1128/aac.02593-17] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 03/16/2018] [Indexed: 12/21/2022] Open
Abstract
The antifungal drug 5-flucytosine (5FC), a derivative of the nucleobase cytosine, is licensed for the treatment of fungal diseases; however, it is rarely used as a monotherapeutic to treat Aspergillus infection. Despite being potent against other fungal pathogens, 5FC has limited activity against Aspergillus fumigatus when standard in vitro assays are used to determine susceptibility. However, in modified in vitro assays where the pH is set to pH 5, the activity of 5FC increases significantly. Here we provide evidence that fcyB, a gene that encodes a purine-cytosine permease orthologous to known 5FC importers, is downregulated at pH 7 and is the primary factor responsible for the low efficacy of 5FC at pH 7. We also uncover two transcriptional regulators that are responsible for the repression of fcyB and, consequently, mediators of 5FC resistance, the CCAAT binding complex (CBC) and the pH regulatory protein PacC. We propose that the activity of 5FC might be enhanced by the perturbation of factors that repress fcyB expression, such as PacC or other components of the pH-sensing machinery.
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13
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Miller JJ, Lau AZ, Tyler DJ. Susceptibility-induced distortion correction in hyperpolarized echo planar imaging. Magn Reson Med 2017; 79:2135-2141. [PMID: 28722201 PMCID: PMC5836862 DOI: 10.1002/mrm.26839] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Revised: 06/02/2017] [Accepted: 06/24/2017] [Indexed: 12/13/2022]
Abstract
Purpose Echo planar imaging is an attractive rapid imaging readout that can image hyperpolarized compounds in vivo. By alternating the sign of the phase encoding gradient waveform, spatial offsets arising from uncertain frequency shifts can be determined. We show here that blip‐reversed echo planar imaging can also be used to correct for susceptibility and B0 inhomogeneity effects that would otherwise produce image‐domain distortion in the heart. Methods Previously acquired blip‐reversed cardiac 3D‐Spectral‐Spatial echo planar imaging volumetric timecourses of hyperpolarized [1‐13C]pyruvate were distortion corrected by a deformation field estimated by reconstructing signal‐to‐noise ratio (SNR)‐weighted progressively subsampled temporally summed images of each metabolite. Results Reconstructing blip‐reversed data as proposed produced volumetric timecourses that overlaid with proton reference images more consistently than without such corrections. Conclusion The method proposed may form an attractive method to correct for image‐domain distortions in hyperpolarized echo planar imaging experiments. Magn Reson Med 79:2135–2141, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
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Affiliation(s)
- Jack J Miller
- Department of Physiology, Anatomy & Genetics, Sherrington Building, University of Oxford, Oxford, United Kingdom.,Department of Physics, Clarendon Laboratory, University of Oxford, Oxford, United Kingdom
| | - Angus Z Lau
- Department of Physics, Clarendon Laboratory, University of Oxford, Oxford, United Kingdom.,Health Sciences, Sunnybrook Research Institute, Toronto, Ontario, Canada
| | - Damian J Tyler
- Department of Physiology, Anatomy & Genetics, Sherrington Building, University of Oxford, Oxford, United Kingdom
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14
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Pourfathi M, Xin Y, Kadlecek SJ, Cereda MF, Profka H, Hamedani H, Siddiqui SM, Ruppert K, Drachman NA, Rajaei JN, Rizi RR. In vivo imaging of the progression of acute lung injury using hyperpolarized [1- 13 C] pyruvate. Magn Reson Med 2017; 78:2106-2115. [PMID: 28074497 DOI: 10.1002/mrm.26604] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2016] [Revised: 11/29/2016] [Accepted: 12/20/2016] [Indexed: 12/19/2022]
Abstract
PURPOSE To investigate pulmonary metabolic alterations during progression of acute lung injury. METHODS Using hyperpolarized [1-13 C] pyruvate imaging, we measured pulmonary lactate and pyruvate in 15 ventilated rats 1, 2, and 4 h after initiation of mechanical ventilation. Lung compliance was used as a marker for injury progression. 5 untreated rats were used as controls; 5 rats (injured-1) received 1 ml/kg and another 5 rats (injured-2) received 2 ml/kg hydrochloric acid (pH 1.25) in the trachea at 70 min. RESULTS The mean lactate-to-pyruvate ratio of the injured-1 cohort was 0.15 ± 0.02 and 0.15 ± 0.03 at baseline and 1 h after the injury, and significantly increased from the baseline value 3 h after the injury to 0.23 ± 0.02 (P = 0.002). The mean lactate-to-pyruvate ratio of the injured-2 cohort decreased from 0.14 ± 0.03 at baseline to 0.08 ± 0.02 1 h after the injury and further decreased to 0.07 ± 0.02 (P = 0.08) 3 h after injury. No significant change was observed in the control group. Compliance in both injured groups decreased significantly after the injury (P < 0.01). CONCLUSIONS Our findings suggest that in severe cases of lung injury, edema and hyperperfusion in the injured lung tissue may complicate interpretation of the pulmonary lactate-to-pyruvate ratio as a marker of inflammation. However, combining the lactate-to-pyruvate ratio with pulmonary compliance provides more insight into the progression of the injury and its severity. Magn Reson Med 78:2106-2115, 2017. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Mehrdad Pourfathi
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Yi Xin
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Stephen J Kadlecek
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Maurizio F Cereda
- Department of Anesthesiology and Critical Care, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Harrilla Profka
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Hooman Hamedani
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Sarmad M Siddiqui
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Kai Ruppert
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Nicholas A Drachman
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Jennia N Rajaei
- School of Medicine, Stanford University, Stanford, California, USA
| | - Rahim R Rizi
- Department of Radiology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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15
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Drachman N, Kadlecek S, Duncan I, Rizi R. Quantifying reaction kinetics of the non-enzymatic decarboxylation of pyruvate and production of peroxymonocarbonate with hyperpolarized13C-NMR. Phys Chem Chem Phys 2017; 19:19316-19325. [DOI: 10.1039/c7cp02041d] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Hyperpolarized13C-NMR is used to study the reaction mechanism and kinetics for non-enzymatic decarboxylation of pyruvate and formation of peroxymonocarbonate.
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Affiliation(s)
| | | | - Ian Duncan
- University of Pennsylvania
- Radiology
- Philadelphia
- USA
| | - Rahim Rizi
- University of Pennsylvania
- Radiology
- Philadelphia
- USA
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