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Graf C, Stollberger R, Rund A, Schweiger M, Diwoky C. Robust dual-angle T 1 $$ {T}_1 $$ measurement in magnetization transfer spectroscopy by time-optimal control. NMR IN BIOMEDICINE 2024:e5151. [PMID: 38583871 DOI: 10.1002/nbm.5151] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 02/07/2024] [Accepted: 03/01/2024] [Indexed: 04/09/2024]
Abstract
Magnetization transfer spectroscopy relies heavily on the robust determination ofT 1 $$ {T}_1 $$ relaxation times of nuclei participating in metabolic exchange. Challenges arise due to the use of surface RF coils for transmission (highB 1 + $$ {B}_1^{+} $$ variation) and the broad resonance band of most X nuclei. These challenges are particularly pronounced when fastT 1 $$ {T}_1 $$ mapping methods, such as the dual-angle method, are employed. Consequently, in this work, we develop resonance offset andB 1 + $$ {B}_1^{+} $$ robust excitation RF pulses for 31P magnetization transfer spectroscopy at 7T through ensemble-based time-optimal control. In our approach, we introduce a cost functional for designing robust pulses, incorporating the full Bloch equations as constraints, which are solved using symmetric operator splitting techniques. The optimal control design of the RF pulses developed demonstrates improved accuracy, desired phase properties, and reduced RF power when applied to dual-angleT 1 $$ {T}_1 $$ mapping, thereby improving the precision of exchange-rate measurements, as demonstrated in a preclinical in vivo study quantifying brain creatine kinase activity.
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Affiliation(s)
- Christina Graf
- Institute of Biomedical Imaging, Graz University of Technology, Graz, Austria
- Department of Pediatrics, University of British Columbia, Vancouver, BC, Canada
| | - Rudolf Stollberger
- Institute of Biomedical Imaging, Graz University of Technology, Graz, Austria
- BioTechMed-Graz, Graz, Austria
| | - Armin Rund
- Institute for Mathematics and Scientific Computing, Karl-Franzens University Graz, Graz, Austria
| | - Martina Schweiger
- BioTechMed-Graz, Graz, Austria
- Institute of Molecular Biosciences, Karl-Franzens University Graz, Graz, Austria
- Field of Excellence BioHealthKarl-Franzens University Graz, Graz, Austria
| | - Clemens Diwoky
- Institute of Molecular Biosciences, Karl-Franzens University Graz, Graz, Austria
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2
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Fear EJ, Torkelsen FH, Zamboni E, Chen K, Scott M, Jeffery G, Baseler H, Kennerley AJ. Use of 31 P magnetisation transfer magnetic resonance spectroscopy to measure ATP changes after 670 nm transcranial photobiomodulation in older adults. Aging Cell 2023; 22:e14005. [PMID: 37803929 PMCID: PMC10652330 DOI: 10.1111/acel.14005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 09/18/2023] [Accepted: 09/22/2023] [Indexed: 10/08/2023] Open
Abstract
Mitochondrial function declines with age, and many pathological processes in neurodegenerative diseases stem from this dysfunction when mitochondria fail to produce the necessary energy required. Photobiomodulation (PBM), long-wavelength light therapy, has been shown to rescue mitochondrial function in animal models and improve human health, but clinical uptake is limited due to uncertainty around efficacy and the mechanisms responsible. Using 31 P magnetisation transfer magnetic resonance spectroscopy (MT-MRS) we quantify, for the first time, the effects of 670 nm PBM treatment on healthy ageing human brains. We find a significant increase in the rate of ATP synthase flux in the brain after PBM in a cohort of older adults. Our study provides initial evidence of PBM therapeutic efficacy for improving mitochondrial function and restoring ATP flux with age, but recognises that wider studies are now required to confirm any resultant cognitive benefits.
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Affiliation(s)
- Elizabeth J. Fear
- Hull York Medical SchoolUniversity of YorkYorkUK
- Department of Biomolecular SciencesUniversity of Urbino Carlo BoUrbinoItaly
| | | | - Elisa Zamboni
- Department of PsychologyUniversity of YorkYorkUK
- School of PsychologyUniversity of NottinghamNottinghamUK
| | | | - Martin Scott
- Department of PsychologyUniversity of YorkYorkUK
- Department of PsychologyStanford UniversityStanfordCaliforniaUSA
| | - Glenn Jeffery
- Faculty of Brain SciencesInstitute of Ophthalmology, UCLLondonUK
| | - Heidi Baseler
- Hull York Medical SchoolUniversity of YorkYorkUK
- Department of PsychologyUniversity of YorkYorkUK
| | - Aneurin J. Kennerley
- Department of ChemistryUniversity of YorkYorkUK
- Institute of SportManchester Metropolitan UniversityManchesterUK
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3
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Theillet FX, Luchinat E. In-cell NMR: Why and how? PROGRESS IN NUCLEAR MAGNETIC RESONANCE SPECTROSCOPY 2022; 132-133:1-112. [PMID: 36496255 DOI: 10.1016/j.pnmrs.2022.04.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 04/19/2022] [Accepted: 04/27/2022] [Indexed: 06/17/2023]
Abstract
NMR spectroscopy has been applied to cells and tissues analysis since its beginnings, as early as 1950. We have attempted to gather here in a didactic fashion the broad diversity of data and ideas that emerged from NMR investigations on living cells. Covering a large proportion of the periodic table, NMR spectroscopy permits scrutiny of a great variety of atomic nuclei in all living organisms non-invasively. It has thus provided quantitative information on cellular atoms and their chemical environment, dynamics, or interactions. We will show that NMR studies have generated valuable knowledge on a vast array of cellular molecules and events, from water, salts, metabolites, cell walls, proteins, nucleic acids, drugs and drug targets, to pH, redox equilibria and chemical reactions. The characterization of such a multitude of objects at the atomic scale has thus shaped our mental representation of cellular life at multiple levels, together with major techniques like mass-spectrometry or microscopies. NMR studies on cells has accompanied the developments of MRI and metabolomics, and various subfields have flourished, coined with appealing names: fluxomics, foodomics, MRI and MRS (i.e. imaging and localized spectroscopy of living tissues, respectively), whole-cell NMR, on-cell ligand-based NMR, systems NMR, cellular structural biology, in-cell NMR… All these have not grown separately, but rather by reinforcing each other like a braided trunk. Hence, we try here to provide an analytical account of a large ensemble of intricately linked approaches, whose integration has been and will be key to their success. We present extensive overviews, firstly on the various types of information provided by NMR in a cellular environment (the "why", oriented towards a broad readership), and secondly on the employed NMR techniques and setups (the "how", where we discuss the past, current and future methods). Each subsection is constructed as a historical anthology, showing how the intrinsic properties of NMR spectroscopy and its developments structured the accessible knowledge on cellular phenomena. Using this systematic approach, we sought i) to make this review accessible to the broadest audience and ii) to highlight some early techniques that may find renewed interest. Finally, we present a brief discussion on what may be potential and desirable developments in the context of integrative studies in biology.
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Affiliation(s)
- Francois-Xavier Theillet
- Université Paris-Saclay, CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), 91198 Gif-sur-Yvette, France.
| | - Enrico Luchinat
- Dipartimento di Scienze e Tecnologie Agro-Alimentari, Alma Mater Studiorum - Università di Bologna, Piazza Goidanich 60, 47521 Cesena, Italy; CERM - Magnetic Resonance Center, and Neurofarba Department, Università degli Studi di Firenze, 50019 Sesto Fiorentino, Italy
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4
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Wang C, Kim K, Yu X. Rapid In Vivo Quantification of Creatine Kinase Activity by Phosphorous-31 Magnetic Resonance Spectroscopic Fingerprinting ( 31P-MRSF). Methods Mol Biol 2022; 2393:597-609. [PMID: 34837201 DOI: 10.1007/978-1-0716-1803-5_31] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Creatine kinase (CK) plays an important role in tissue metabolism by providing a buffering mechanism for maintaining a constant supply of adenosine triphosphate (ATP) during metabolic perturbations. Phosphorous-31 magnetic resonance spectroscopy (31P-MRS) employing magnetization transfer techniques is the only noninvasive method for measuring the rate of ATP synthesis via creatine kinase. However, due to the low concentrations of phosphate metabolites, current 31P-MRS methods require long acquisition time to achieve adequate measurement accuracy. In this chapter, we present a new framework of data acquisition and parameter estimation, the 31P magnetic resonance spectroscopic fingerprinting (31P-MRSF) method, for rapid quantification of CK reaction rate constant in the hindlimb of small laboratory animals.
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Affiliation(s)
- Charlie Wang
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
| | - Kihwan Kim
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
| | - Xin Yu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA.
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5
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Kim K, Gu Y, Wang CY, Clifford B, Huang S, Liang ZP, Yu X. Quantification of creatine kinase reaction rate in mouse hindlimb using phosphorus-31 magnetic resonance spectroscopic fingerprinting. NMR IN BIOMEDICINE 2021; 34:e4435. [PMID: 33111456 PMCID: PMC8324327 DOI: 10.1002/nbm.4435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2020] [Revised: 09/10/2020] [Accepted: 10/08/2020] [Indexed: 06/11/2023]
Abstract
The goal of this study was to evaluate the accuracy, reproducibility, and efficiency of a 31 P magnetic resonance spectroscopic fingerprinting (31 P-MRSF) method for fast quantification of the forward rate constant of creatine kinase (CK) in mouse hindlimb. The 31 P-MRSF method acquired spectroscopic fingerprints using interleaved acquisition of phosphocreatine (PCr) and γATP with ramped flip angles and a saturation scheme sensitive to chemical exchange between PCr and γATP. Parameter estimation was performed by matching the acquired fingerprints to a dictionary of simulated fingerprints generated from the Bloch-McConnell model. The accuracy of 31 P-MRSF measurements was compared with the magnetization transfer (MT-MRS) method in mouse hindlimb at 9.4 T (n = 8). The reproducibility of 31 P-MRSF was also assessed by repeated measurements. Estimation of the CK rate constant using 31 P-MRSF (0.39 ± 0.03 s-1 ) showed a strong agreement with that using MT-MRS measurements (0.40 ± 0.05 s-1 ). Variations less than 10% were achieved with 2 min acquisition of 31 P-MRSF data. Application of the 31 P-MRSF method to mice subjected to an electrical stimulation protocol detected an increase in CK rate constant in response to stimulation-induced muscle contraction. These results demonstrated the potential of the 31 P-MRSF framework for rapid, accurate, and reproducible quantification of the chemical exchange rate of CK in vivo.
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Affiliation(s)
- Kihwan Kim
- Department of Biomedical Engineering and Case Center for Imaging Research, Case Western Reserve University, Cleveland, Ohio
| | - Yuning Gu
- Department of Biomedical Engineering and Case Center for Imaging Research, Case Western Reserve University, Cleveland, Ohio
| | - Charlie Y. Wang
- Department of Biomedical Engineering and Case Center for Imaging Research, Case Western Reserve University, Cleveland, Ohio
| | - Bryan Clifford
- Department of Electrical and Computer Engineering and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - Sherry Huang
- Department of Biomedical Engineering and Case Center for Imaging Research, Case Western Reserve University, Cleveland, Ohio
| | - Zhi-Pei Liang
- Department of Electrical and Computer Engineering and Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois
| | - Xin Yu
- Department of Biomedical Engineering and Case Center for Imaging Research, Case Western Reserve University, Cleveland, Ohio
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6
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Ren J, Sherry AD, Malloy CR. Modular 31 P wideband inversion transfer for integrative analysis of adenosine triphosphate metabolism, T 1 relaxation and molecular dynamics in skeletal muscle at 7T. Magn Reson Med 2019; 81:3440-3452. [PMID: 30793793 DOI: 10.1002/mrm.27686] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 01/16/2019] [Accepted: 01/18/2019] [Indexed: 12/13/2022]
Abstract
PURPOSE For efficient and integrative analysis of de novo adenosine triphosphate (ATP) synthesis, creatine-kinase-mediated ATP synthesis, T1 relaxation time, and ATP molecular motion dynamics in human skeletal muscle at rest. METHODS Four inversion-transfer modules differing in center inversion frequency were combined to generate amplified magnetization transfer (MT) effects in targeted MT pathways, including Pi ↔ γ-ATP, PCr ↔ γ-ATP, and 31 Pγ(α)ATP ↔ 31 PβATP . MT effects from both forward and reverse exchange kinetic pathways were acquired to reduce potential bias and confounding factors in integrated data analysis. RESULTS Kinetic data collected using 4 wideband inversion modules (8 minutes each) yielded the forward exchange rate constants, kPCr →γ ATP = 0.31 ± 0.05 s-1 and kPi →γ ATP = 0.064 ± 0.012 s-1 , and the reverse exchange rate constants, kγATP→Pi = 0.034 ± 0.006 s-1 and kγATP→PCr = 1.37 ± 0.22 s-1 , respectively. The cross-relaxation rate constant, σγ(α) ↔ βATP was -0.20 ± 0.03 s-1 , corresponding to ATP rotational correlation time τc of 0.8 ± 0.1 × 10-7 seconds. The intrinsic T1 relaxation times were Pi (9.2 ± 1.4 seconds), PCr (6.2 ± 0.4 seconds), γ-ATP (1.8 ± 0.1 seconds), α-ATP (1.4 ± 0.1 seconds), and β-ATP (1.1 ± 0.1 seconds). Muscle ATP T1 values were found to be significantly longer than those previously measured in the brain using a similar method. CONCLUSION A combination of multiple inversion transfer modules provides a comprehensive and integrated analysis of ATP metabolism and molecular motion dynamics. This relatively fast technique could be potentially useful for studying metabolic disorders in skeletal muscle.
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Affiliation(s)
- Jimin Ren
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas.,Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - A Dean Sherry
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas.,Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas.,Department of Chemistry, University of Texas at Dallas, Richardson, Texas
| | - Craig R Malloy
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas.,Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas.,Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas.,VA North Texas Health Care System, Dallas, Texas
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Lane AN, Higashi RM, Fan TWM. NMR and MS-based Stable Isotope-Resolved Metabolomics and Applications in Cancer Metabolism. Trends Analyt Chem 2018; 120. [PMID: 32523238 DOI: 10.1016/j.trac.2018.11.020] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
There is considerable interest in defining metabolic reprogramming in human diseases, which is recognized as a hallmark of human cancer. Although radiotracers have a long history in specific metabolic studies, stable isotope-enriched precursors coupled with modern high resolution mass spectrometry and NMR spectroscopy have enabled systematic mapping of metabolic networks and fluxes in cells, tissues and living organisms including humans. These analytical platforms are high in information content, are complementary and cross-validating in terms of compound identification, quantification, and isotope labeling pattern analysis of a large number of metabolites simultaneously. Furthermore, new developments in chemoselective derivatization and in vivo spectroscopy enable tracking of labile/low abundance metabolites and metabolic kinetics in real-time. Here we review developments in Stable Isotope Resolved Metabolomics (SIRM) and recent applications in cancer metabolism using a wide variety of stable isotope tracers that probe both broad and specific aspects of cancer metabolism required for proliferation and survival.
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Affiliation(s)
- Andrew N Lane
- Center for Environmental and Systems Biochemistry, Dept. Toxicology and Cancer Biology, Markey Cancer Center, University of Kentucky, 789 S. Limestone St., Lexington, KY 40536 USA
| | - Richard M Higashi
- Center for Environmental and Systems Biochemistry, Dept. Toxicology and Cancer Biology, Markey Cancer Center, University of Kentucky, 789 S. Limestone St., Lexington, KY 40536 USA
| | - Teresa W-M Fan
- Center for Environmental and Systems Biochemistry, Dept. Toxicology and Cancer Biology, Markey Cancer Center, University of Kentucky, 789 S. Limestone St., Lexington, KY 40536 USA
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8
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Petersen MC, Shulman GI. Mechanisms of Insulin Action and Insulin Resistance. Physiol Rev 2018; 98:2133-2223. [PMID: 30067154 PMCID: PMC6170977 DOI: 10.1152/physrev.00063.2017] [Citation(s) in RCA: 1352] [Impact Index Per Article: 225.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2017] [Revised: 03/22/2018] [Accepted: 03/24/2018] [Indexed: 12/15/2022] Open
Abstract
The 1921 discovery of insulin was a Big Bang from which a vast and expanding universe of research into insulin action and resistance has issued. In the intervening century, some discoveries have matured, coalescing into solid and fertile ground for clinical application; others remain incompletely investigated and scientifically controversial. Here, we attempt to synthesize this work to guide further mechanistic investigation and to inform the development of novel therapies for type 2 diabetes (T2D). The rational development of such therapies necessitates detailed knowledge of one of the key pathophysiological processes involved in T2D: insulin resistance. Understanding insulin resistance, in turn, requires knowledge of normal insulin action. In this review, both the physiology of insulin action and the pathophysiology of insulin resistance are described, focusing on three key insulin target tissues: skeletal muscle, liver, and white adipose tissue. We aim to develop an integrated physiological perspective, placing the intricate signaling effectors that carry out the cell-autonomous response to insulin in the context of the tissue-specific functions that generate the coordinated organismal response. First, in section II, the effectors and effects of direct, cell-autonomous insulin action in muscle, liver, and white adipose tissue are reviewed, beginning at the insulin receptor and working downstream. Section III considers the critical and underappreciated role of tissue crosstalk in whole body insulin action, especially the essential interaction between adipose lipolysis and hepatic gluconeogenesis. The pathophysiology of insulin resistance is then described in section IV. Special attention is given to which signaling pathways and functions become insulin resistant in the setting of chronic overnutrition, and an alternative explanation for the phenomenon of ‟selective hepatic insulin resistanceˮ is presented. Sections V, VI, and VII critically examine the evidence for and against several putative mediators of insulin resistance. Section V reviews work linking the bioactive lipids diacylglycerol, ceramide, and acylcarnitine to insulin resistance; section VI considers the impact of nutrient stresses in the endoplasmic reticulum and mitochondria on insulin resistance; and section VII discusses non-cell autonomous factors proposed to induce insulin resistance, including inflammatory mediators, branched-chain amino acids, adipokines, and hepatokines. Finally, in section VIII, we propose an integrated model of insulin resistance that links these mediators to final common pathways of metabolite-driven gluconeogenesis and ectopic lipid accumulation.
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Affiliation(s)
- Max C Petersen
- Departments of Internal Medicine and Cellular & Molecular Physiology, Howard Hughes Medical Institute, Yale University School of Medicine , New Haven, Connecticut
| | - Gerald I Shulman
- Departments of Internal Medicine and Cellular & Molecular Physiology, Howard Hughes Medical Institute, Yale University School of Medicine , New Haven, Connecticut
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Abstract
BACKGROUND There is evidence that the brain's energy status is lowered in obesity despite of chronic hypercaloric nutrition. The underlying mechanisms are unknown. We hypothesized that the brain of obese people does not appropriately generate energy in response to a hypercaloric supply. METHODS Glucose was intravenously infused in 17 normal weights and 13 obese participants until blood glucose concentrations reached the postprandial levels of 7 mmol/L and 10 mmol/L. Changes in cerebral adenosine triphosphate (ATP) and phosphocreatine (PCr) content were measured by 31phosphorus magnetic resonance spectroscopy and stress hormonal measures regulating glucose homeostasis were monitored. Because vitamin C is crucial for a proper neuronal energy synthesis we determined circulating concentrations during the experimental testing. RESULTS Cerebral high-energy phosphates were increased at blood glucose levels of 7 mmol/L in normal weights, which was completely missing in the obese. Brain energy content moderately raised only at blood glucose levels of 10 mmol/L in obese participants. Vitamin C concentrations generally correlated with the brain energy content at blood glucose concentrations of 7 mmol/L. CONCLUSIONS Our data demonstrate an inefficient cerebral energy gain upon a glucose load in obese men, which may result from a dysfunctional glucose transport across the blood-brain barrier or a downregulated energy synthesis in mitochondrial oxidation processes. Our finding offers an explanation for the chronic neuroenergetic deficiency and respectively missing satiety perception in obesity.
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Affiliation(s)
- Ewelina K Wardzinski
- Section of Psychoneurobiology, Center of Brain, Behavior and Metabolism, University of Luebeck, Germany.
| | - Alina Kistenmacher
- Section of Psychoneurobiology, Center of Brain, Behavior and Metabolism, University of Luebeck, Germany.
| | - Uwe H Melchert
- Section of Psychoneurobiology, Center of Brain, Behavior and Metabolism, University of Luebeck, Germany.
| | - Kamila Jauch-Chara
- Section of Psychoneurobiology, Center of Brain, Behavior and Metabolism, University of Luebeck, Germany.
| | - Kerstin M Oltmanns
- Section of Psychoneurobiology, Center of Brain, Behavior and Metabolism, University of Luebeck, Germany.
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10
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Wang CY, Liu Y, Huang S, Griswold MA, Seiberlich N, Yu X. 31 P magnetic resonance fingerprinting for rapid quantification of creatine kinase reaction rate in vivo. NMR IN BIOMEDICINE 2017; 30:10.1002/nbm.3786. [PMID: 28915341 PMCID: PMC5690599 DOI: 10.1002/nbm.3786] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 06/14/2017] [Accepted: 07/12/2017] [Indexed: 05/25/2023]
Abstract
The purpose of this work was to develop a 31 P spectroscopic magnetic resonance fingerprinting (MRF) method for fast quantification of the chemical exchange rate between phosphocreatine (PCr) and adenosine triphosphate (ATP) via creatine kinase (CK). A 31 P MRF sequence (CK-MRF) was developed to quantify the forward rate constant of ATP synthesis via CK ( kfCK), the T1 relaxation time of PCr ( T1PCr), and the PCr-to-ATP concentration ratio ( MRPCr). The CK-MRF sequence used a balanced steady-state free precession (bSSFP)-type excitation with ramped flip angles and a unique saturation scheme sensitive to the exchange between PCr and γATP. Parameter estimation was accomplished by matching the acquired signals to a dictionary generated using the Bloch-McConnell equation. Simulation studies were performed to examine the susceptibility of the CK-MRF method to several potential error sources. The accuracy of nonlocalized CK-MRF measurements before and after an ischemia-reperfusion (IR) protocol was compared with the magnetization transfer (MT-MRS) method in rat hindlimb at 9.4 T (n = 14). The reproducibility of CK-MRF was also assessed by comparing CK-MRF measurements with both MT-MRS (n = 17) and four angle saturation transfer (FAST) (n = 7). Simulation results showed that CK-MRF quantification of kfCK was robust, with less than 5% error in the presence of model inaccuracies including dictionary resolution, metabolite T2 values, inorganic phosphate metabolism, and B1 miscalibration. Estimation of kfCK by CK-MRF (0.38 ± 0.02 s-1 at baseline and 0.42 ± 0.03 s-1 post-IR) showed strong agreement with MT-MRS (0.39 ± 0.03 s-1 at baseline and 0.44 ± 0.04 s-1 post-IR). kfCK estimation was also similar between CK-MRF and FAST (0.38 ± 0.02 s-1 for CK-MRF and 0.38 ± 0.11 s-1 for FAST). The coefficient of variation from 20 s CK-MRF quantification of kfCK was 42% of that by 150 s MT-MRS acquisition and was 12% of that by 20 s FAST acquisition. This study demonstrates the potential of a 31 P spectroscopic MRF framework for rapid, accurate and reproducible quantification of chemical exchange rate of CK in vivo.
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Affiliation(s)
- Charlie Y. Wang
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio
| | - Yuchi Liu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio
| | - Shuying Huang
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio
| | - Mark A. Griswold
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio
- Department of Radiology, Case Western Reserve University, Cleveland, Ohio
| | - Nicole Seiberlich
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio
- Department of Radiology, Case Western Reserve University, Cleveland, Ohio
| | - Xin Yu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio
- Department of Radiology, Case Western Reserve University, Cleveland, Ohio
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, Ohio
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Liu Y, Gu Y, Yu X. Assessing tissue metabolism by phosphorous-31 magnetic resonance spectroscopy and imaging: a methodology review. Quant Imaging Med Surg 2017; 7:707-726. [PMID: 29312876 PMCID: PMC5756783 DOI: 10.21037/qims.2017.11.03] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 11/11/2017] [Indexed: 01/11/2023]
Abstract
Many human diseases are caused by an imbalance between energy production and demand. Magnetic resonance spectroscopy (MRS) and magnetic resonance imaging (MRI) provide the unique opportunity for in vivo assessment of several fundamental events in tissue metabolism without the use of ionizing radiation. Of particular interest, phosphate metabolites that are involved in ATP generation and utilization can be quantified noninvasively by phosphorous-31 (31P) MRS/MRI. Furthermore, 31P magnetization transfer (MT) techniques allow in vivo measurement of metabolic fluxes via creatine kinase (CK) and ATP synthase. However, a major impediment for the clinical applications of 31P-MRS/MRI is the prohibitively long acquisition time and/or the low spatial resolution that are necessary to achieve adequate signal-to-noise ratio. In this review, current 31P-MRS/MRI techniques used in basic science and clinical research are presented. Recent advances in the development of fast 31P-MRS/MRI methods are also discussed.
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Affiliation(s)
- Yuchi Liu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
| | - Yuning Gu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
| | - Xin Yu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH, USA
- Department of Radiology, Case Western Reserve University, Cleveland, OH, USA
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH, USA
- Case Center for Imaging Research, Case Western Reserve University, Cleveland, OH, USA
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Traussnigg S, Kienbacher C, Gajdošík M, Valkovič L, Halilbasic E, Stift J, Rechling C, Hofer H, Steindl‐Munda P, Ferenci P, Wrba F, Trattnig S, Krššák M, Trauner M. Ultra-high-field magnetic resonance spectroscopy in non-alcoholic fatty liver disease: Novel mechanistic and diagnostic insights of energy metabolism in non-alcoholic steatohepatitis and advanced fibrosis. Liver Int 2017; 37:1544-1553. [PMID: 28544208 PMCID: PMC5638103 DOI: 10.1111/liv.13451] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
BACKGROUND & AIMS With the rising prevalence of non-alcoholic fatty liver disease (NAFLD) and steatohepatitis (NASH) non-invasive tools obtaining pathomechanistic insights to improve risk stratification are urgently needed. We therefore explored high- and ultra-high-field magnetic resonance spectroscopy (MRS) to obtain novel mechanistic and diagnostic insights into alterations of hepatic lipid, cell membrane and energy metabolism across the spectrum of NAFLD. METHODS MRS and liver biopsy were performed in 30 NAFLD patients with NAFL (n=8) or NASH (n=22). Hepatic lipid content and composition were measured using 3-Tesla proton (1 H)-MRS. 7-Tesla phosphorus (31 P)-MRS was applied to determine phosphomonoester (PME) including phosphoethanolamine (PE), phosphodiester (PDE) including glycerophosphocholine (GPC), phosphocreatine (PCr), nicotinamide adenine dinucleotide phosphate (NADPH), inorganic phosphate (Pi), γ-ATP and total phosphorus (TP). Saturation transfer technique was used to quantify hepatic ATP flux. RESULTS Hepatic steatosis in 1 H-MRS highly correlated with histology (P<.001) showing higher values in NASH than NAFL (P<.001) without differences in saturated or unsaturated fatty acid indices. PE/TP ratio increased with advanced fibrosis (F3/4) (P=.002) whereas GPC/PME+PDE decreased (P=.05) compared to no/mild fibrosis (F0-2). γ-ATP/TP was lower in advanced fibrosis (P=.049), while PCr/TP increased (P=.01). NADPH/TP increased with higher grades of ballooning (P=.02). Pi-to-ATP exchange rate constant (P=.003) and ATP flux (P=.001) were lower in NASH than NAFL. CONCLUSIONS Ultra-high-field MRS, especially saturation transfer technique uncovers changes in energy metabolism including dynamic ATP flux in inflammation and fibrosis in NASH. Non-invasive profiling by MRS appears feasible and may assist further mechanistic and therapeutic studies in NAFLD/NASH.
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Affiliation(s)
- Stefan Traussnigg
- Division of Gastroenterology and HepatologyDepartment of Internal Medicine IIIMedical University of ViennaViennaAustria
| | - Christian Kienbacher
- Division of Gastroenterology and HepatologyDepartment of Internal Medicine IIIMedical University of ViennaViennaAustria
| | - Martin Gajdošík
- High‐Field MR CenterDepartment of Biomedical Imaging and Image‐guided TherapyMedical University of ViennaViennaAustria,Christian Doppler Laboratory for Clinical Molecular MR ImagingViennaAustria
| | - Ladislav Valkovič
- High‐Field MR CenterDepartment of Biomedical Imaging and Image‐guided TherapyMedical University of ViennaViennaAustria,Christian Doppler Laboratory for Clinical Molecular MR ImagingViennaAustria,Department of Imaging MethodsInstitute of Measurement ScienceSlovak Academy of SciencesBratislavaSlovakia
| | - Emina Halilbasic
- Division of Gastroenterology and HepatologyDepartment of Internal Medicine IIIMedical University of ViennaViennaAustria
| | - Judith Stift
- Department of Clinical PathologyMedical University of ViennaViennaAustria
| | - Christian Rechling
- Division of Gastroenterology and HepatologyDepartment of Internal Medicine IIIMedical University of ViennaViennaAustria
| | - Harald Hofer
- Division of Gastroenterology and HepatologyDepartment of Internal Medicine IIIMedical University of ViennaViennaAustria
| | - Petra Steindl‐Munda
- Division of Gastroenterology and HepatologyDepartment of Internal Medicine IIIMedical University of ViennaViennaAustria
| | - Peter Ferenci
- Division of Gastroenterology and HepatologyDepartment of Internal Medicine IIIMedical University of ViennaViennaAustria
| | - Fritz Wrba
- Department of Clinical PathologyMedical University of ViennaViennaAustria
| | - Siegfried Trattnig
- High‐Field MR CenterDepartment of Biomedical Imaging and Image‐guided TherapyMedical University of ViennaViennaAustria,Christian Doppler Laboratory for Clinical Molecular MR ImagingViennaAustria
| | - Martin Krššák
- High‐Field MR CenterDepartment of Biomedical Imaging and Image‐guided TherapyMedical University of ViennaViennaAustria,Christian Doppler Laboratory for Clinical Molecular MR ImagingViennaAustria,Division of Endocrinology and MetabolismDepartment of Internal Medicine IIIMedical University of ViennaViennaAustria
| | - Michael Trauner
- Division of Gastroenterology and HepatologyDepartment of Internal Medicine IIIMedical University of ViennaViennaAustria
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Stovell MG, Yan JL, Sleigh A, Mada MO, Carpenter TA, Hutchinson PJA, Carpenter KLH. Assessing Metabolism and Injury in Acute Human Traumatic Brain Injury with Magnetic Resonance Spectroscopy: Current and Future Applications. Front Neurol 2017; 8:426. [PMID: 28955291 PMCID: PMC5600917 DOI: 10.3389/fneur.2017.00426] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2017] [Accepted: 08/07/2017] [Indexed: 11/25/2022] Open
Abstract
Traumatic brain injury (TBI) triggers a series of complex pathophysiological processes. These include abnormalities in brain energy metabolism; consequent to reduced tissue pO2 arising from ischemia or abnormal tissue oxygen diffusion, or due to a failure of mitochondrial function. In vivo magnetic resonance spectroscopy (MRS) allows non-invasive interrogation of brain tissue metabolism in patients with acute brain injury. Nuclei with “spin,” e.g., 1H, 31P, and 13C, are detectable using MRS and are found in metabolites at various stages of energy metabolism, possessing unique signatures due to their chemical shift or spin–spin interactions (J-coupling). The most commonly used clinical MRS technique, 1H MRS, uses the great abundance of hydrogen atoms within molecules in brain tissue. Spectra acquired with longer echo-times include N-acetylaspartate (NAA), creatine, and choline. NAA, a marker of neuronal mitochondrial activity related to adenosine triphosphate (ATP), is reported to be lower in patients with TBI than healthy controls, and the ratio of NAA/creatine at early time points may correlate with clinical outcome. 1H MRS acquired with shorter echo times produces a more complex spectrum, allowing detection of a wider range of metabolites.31 P MRS detects high-energy phosphate species, which are the end products of cellular respiration: ATP and phosphocreatine (PCr). ATP is the principal form of chemical energy in living organisms, and PCr is regarded as a readily mobilized reserve for its replenishment during periods of high utilization. The ratios of high-energy phosphates are thought to represent a balance between energy generation, reserve and use in the brain. In addition, the chemical shift difference between inorganic phosphate and PCr enables calculation of intracellular pH.13 C MRS detects the 13C isotope of carbon in brain metabolites. As the natural abundance of 13C is low (1.1%), 13C MRS is typically performed following administration of 13C-enriched substrates, which permits tracking of the metabolic fate of the infused 13C in the brain over time, and calculation of metabolic rates in a range of biochemical pathways, including glycolysis, the tricarboxylic acid cycle, and glutamate–glutamine cycling. The advent of new hyperpolarization techniques to transiently boost signal in 13C-enriched MRS in vivo studies shows promise in this field, and further developments are expected.
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Affiliation(s)
- Matthew G Stovell
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - Jiun-Lin Yan
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom.,Department of Neurosurgery, Keelung Chang Gung Memorial Hospital, Chang Gung University College of Medicine, Taoyuan, Taiwan
| | - Alison Sleigh
- Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom.,National Institute for Health Research/Wellcome Trust Clinical Research Facility, Cambridge University Hospitals NHS Foundation Trust, Cambridge, United Kingdom
| | - Marius O Mada
- Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - T Adrian Carpenter
- Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - Peter J A Hutchinson
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom.,Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
| | - Keri L H Carpenter
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom.,Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, United Kingdom
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Gallez B, Neveu MA, Danhier P, Jordan BF. Manipulation of tumor oxygenation and radiosensitivity through modification of cell respiration. A critical review of approaches and imaging biomarkers for therapeutic guidance. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2017; 1858:700-711. [DOI: 10.1016/j.bbabio.2017.01.002] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Revised: 01/05/2017] [Accepted: 01/06/2017] [Indexed: 11/17/2022]
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15
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Ma C, Clifford B, Liu Y, Gu Y, Lam F, Yu X, Liang ZP. High-resolution dynamic 31 P-MRSI using a low-rank tensor model. Magn Reson Med 2017; 78:419-428. [PMID: 28556373 DOI: 10.1002/mrm.26762] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Revised: 04/04/2017] [Accepted: 05/03/2017] [Indexed: 12/16/2022]
Abstract
PURPOSE To develop a rapid 31 P-MRSI method with high spatiospectral resolution using low-rank tensor-based data acquisition and image reconstruction. METHODS The multidimensional image function of 31 P-MRSI is represented by a low-rank tensor to capture the spatial-spectral-temporal correlations of data. A hybrid data acquisition scheme is used for sparse sampling, which consists of a set of "training" data with limited k-space coverage to capture the subspace structure of the image function, and a set of sparsely sampled "imaging" data for high-resolution image reconstruction. An explicit subspace pursuit approach is used for image reconstruction, which estimates the bases of the subspace from the "training" data and then reconstructs a high-resolution image function from the "imaging" data. RESULTS We have validated the feasibility of the proposed method using phantom and in vivo studies on a 3T whole-body scanner and a 9.4T preclinical scanner. The proposed method produced high-resolution static 31 P-MRSI images (i.e., 6.9 × 6.9 × 10 mm3 nominal resolution in a 15-min acquisition at 3T) and high-resolution, high-frame-rate dynamic 31 P-MRSI images (i.e., 1.5 × 1.5 × 1.6 mm3 nominal resolution, 30 s/frame at 9.4T). CONCLUSIONS Dynamic spatiospectral variations of 31 P-MRSI signals can be efficiently represented by a low-rank tensor. Exploiting this mathematical structure for data acquisition and image reconstruction can lead to fast 31 P-MRSI with high resolution, frame-rate, and SNR. Magn Reson Med 78:419-428, 2017. © 2017 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Chao Ma
- Gordon Center for Medical Imaging, NMMI, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA.,Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Bryan Clifford
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.,Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Yuchi Liu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
| | - Yuning Gu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
| | - Fan Lam
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.,Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Xin Yu
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, Ohio, USA
| | - Zhi-Pei Liang
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA.,Department of Electrical and Computer Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
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16
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Valkovič L, Chmelík M, Krššák M. In-vivo 31P-MRS of skeletal muscle and liver: A way for non-invasive assessment of their metabolism. Anal Biochem 2017; 529:193-215. [PMID: 28119063 PMCID: PMC5478074 DOI: 10.1016/j.ab.2017.01.018] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 01/13/2017] [Accepted: 01/19/2017] [Indexed: 01/18/2023]
Abstract
In addition to direct assessment of high energy phosphorus containing metabolite content within tissues, phosphorus magnetic resonance spectroscopy (31P-MRS) provides options to measure phospholipid metabolites and cellular pH, as well as the kinetics of chemical reactions of energy metabolism in vivo. Even though the great potential of 31P-MR was recognized over 30 years ago, modern MR systems, as well as new, dedicated hardware and measurement techniques provide further opportunities for research of human biochemistry. This paper presents a methodological overview of the 31P-MR techniques that can be used for basic, physiological, or clinical research of human skeletal muscle and liver in vivo. Practical issues of 31P-MRS experiments and examples of potential applications are also provided. As signal localization is essential for liver 31P-MRS and is important for dynamic muscle examinations as well, typical localization strategies for 31P-MR are also described.
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Affiliation(s)
- Ladislav Valkovič
- High-field MR Centre, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria; Oxford Centre for Clinical Magnetic Resonance Research (OCMR), University of Oxford, Oxford, United Kingdom; Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia.
| | - Marek Chmelík
- High-field MR Centre, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria; Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria; Institute for Clinical Molecular MRI in Musculoskeletal System, Karl Landsteiner Society, Vienna, Austria
| | - Martin Krššák
- High-field MR Centre, Department of Biomedical Imaging and Image-guided Therapy, Medical University of Vienna, Vienna, Austria; Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria; Division of Endocrinology and Metabolism, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
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17
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Ren J, Sherry AD, Malloy CR. Efficient 31 P band inversion transfer approach for measuring creatine kinase activity, ATP synthesis, and molecular dynamics in the human brain at 7 T. Magn Reson Med 2016; 78:1657-1666. [PMID: 27868234 DOI: 10.1002/mrm.26560] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Revised: 10/16/2016] [Accepted: 11/03/2016] [Indexed: 01/28/2023]
Abstract
PURPOSE To develop an efficient 31 P magnetic resonance spectroscopy (MRS) method for measuring creatine kinase (CK) activity, adenosine triphosphate (ATP) synthesis, and motion dynamics in the human brain at 7 Tesla (T). METHODS Three band inversion modules differing in center frequency were used to induce magnetization transfer (MT) effect in three exchange pathways: (i) CK-mediated reaction PCr → γ-ATP; (ii) de novo ATP synthesis Pi → γ-ATP; and (iii) ATP intramolecular 31 P-31 P cross-relaxation γ-(α-) ↔ β-ATP. The resultant MT data were analyzed using a 5-pool model in the format of magnetization matrix according to Bloch-McConnell-Solomon formalism. RESULTS With a repetition time (TR) of 4 s, the scan time for each module was approximately 8 min. The rate constants were kPCr → γATP 0.38 ± 0.02 s-1 , kPi → γATP 0.19 ± 0.02 s-1 , and σγ(α) ↔ βATP 0.19 ± 0.04 s-1 , corresponding to ATP rotation correlation time τc (0.8 ± 0.2) ·10-7 s. The T1 relaxation times were Pi 7.26 ± 1.76 s, PCr 5.99 ± 0.58 s, γ-ATP 0.98 ± 0.07 s, α-ATP 0.95 ± 0.04 s, and β-ATP 0.68 ± 0.03 s. CONCLUSION Short-TR band inversion modules provide a time-efficient way of measuring brain ATP metabolism and could be useful in studying metabolic disorders in brain diseases. Magn Reson Med 78:1657-1666, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Jimin Ren
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - A Dean Sherry
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Department of Chemistry, University of Texas at Dallas, Richardson, Texas, USA
| | - Craig R Malloy
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, USA.,VA North Texas Health Care System, Dallas, Texas, USA
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18
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Ren J, Sherry AD, Malloy CR. A simple approach to evaluate the kinetic rate constant for ATP synthesis in resting human skeletal muscle at 7 T. NMR IN BIOMEDICINE 2016; 29:1240-8. [PMID: 25943328 PMCID: PMC4673044 DOI: 10.1002/nbm.3310] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 03/25/2015] [Accepted: 03/27/2015] [Indexed: 05/11/2023]
Abstract
Inversion transfer (IT) is a well-established technique with multiple attractive features for analysis of kinetics. However, its application in measurement of ATP synthesis rate in vivo has lagged behind the more common saturation transfer (ST) techniques. One well-recognized issue with IT is the complexity of data analysis in comparison with much simpler analysis by ST. This complexity arises, in part, because the γ-ATP spin is involved in multiple chemical reactions and magnetization exchanges, whereas Pi is involved in a single reaction, Pi → γ-ATP. By considering the reactions involving γ-ATP only as a lumped constant, the rate constant for the reaction of physiological interest, kPi→γATP , can be determined. Here, we present a new IT data analysis method to evaluate kPi→γATP using data collected from resting human skeletal muscle at 7 T. The method is based on the basic Bloch-McConnell equation, which relates kPi→γATP to m˙Pi, the rate of Pi magnetization change. The kPi→γATP value is accessed from m˙Pi data by more familiar linear correlation approaches. For a group of human subjects (n = 15), the kPi→γATP value derived for resting calf muscle was 0.066 ± 0.017 s(-1) , in agreement with literature-reported values. In this study we also explored possible time-saving strategies to speed up data acquisition for kPi→γATP evaluation using simulations. The analysis indicates that it is feasible to carry out a (31) P IT experiment in about 10 min or less at 7 T with reasonable outcome in kPi→γATP variance for measurement of ATP synthesis in resting human skeletal muscle. We believe that this new IT data analysis approach will facilitate the wide acceptance of IT to evaluate ATP synthesis rate in vivo. Copyright © 2015 John Wiley & Sons, Ltd.
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Affiliation(s)
- Jimin Ren
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX75390
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX75390
| | - A. Dean Sherry
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX75390
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX75390
- Department of Chemistry, University of Texas at Dallas, Richardson, TX75080
| | - Craig R. Malloy
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX75390
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX75390
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX75390
- VA North Texas Health Care System, Dallas, TX75216
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Tiret B, Brouillet E, Valette J. Evidence for a "metabolically inactive" inorganic phosphate pool in adenosine triphosphate synthase reaction using localized 31P saturation transfer magnetic resonance spectroscopy in the rat brain at 11.7 T. J Cereb Blood Flow Metab 2016; 36:1513-8. [PMID: 27354096 PMCID: PMC5012527 DOI: 10.1177/0271678x16657095] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 05/26/2016] [Indexed: 01/08/2023]
Abstract
With the increased spectral resolution made possible at high fields, a second, smaller inorganic phosphate resonance can be resolved on (31)P magnetic resonance spectra in the rat brain. Saturation transfer was used to estimate de novo adenosine triphosphate synthesis reaction rate. While the main inorganic phosphate pool is used by adenosine triphosphate synthase, the second pool is inactive for this reaction. Accounting for this new pool may not only help us understand (31)P magnetic resonance spectroscopy metabolic profiles better but also better quantify adenosine triphosphate synthesis.
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Affiliation(s)
- Brice Tiret
- Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Direction de la Recherche Fondamentale (DRF), Institut d'Imagerie Biomédicale (I2BM), Molecular Imaging Research Center (MIRCen), Fontenay-aux-Roses, France Centre National de la Recherche Scientifique (CNRS), Université Paris-Saclay, UMR 9199, Neurodegenerative Diseases Laboratory, Fontenay-aux-Roses, France
| | - Emmanuel Brouillet
- Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Direction de la Recherche Fondamentale (DRF), Institut d'Imagerie Biomédicale (I2BM), Molecular Imaging Research Center (MIRCen), Fontenay-aux-Roses, France Centre National de la Recherche Scientifique (CNRS), Université Paris-Saclay, UMR 9199, Neurodegenerative Diseases Laboratory, Fontenay-aux-Roses, France
| | - Julien Valette
- Commissariat à l'Energie Atomique et aux Energies Alternatives (CEA), Direction de la Recherche Fondamentale (DRF), Institut d'Imagerie Biomédicale (I2BM), Molecular Imaging Research Center (MIRCen), Fontenay-aux-Roses, France Centre National de la Recherche Scientifique (CNRS), Université Paris-Saclay, UMR 9199, Neurodegenerative Diseases Laboratory, Fontenay-aux-Roses, France
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Rajendran M, Dane E, Conley J, Tantama M. Imaging Adenosine Triphosphate (ATP). THE BIOLOGICAL BULLETIN 2016; 231:73-84. [PMID: 27638696 PMCID: PMC5063237 DOI: 10.1086/689592] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Adenosine triphosphate (ATP) is a universal mediator of metabolism and signaling across unicellular and multicellular species. There is a fundamental interdependence between the dynamics of ATP and the physiology that occurs inside and outside the cell. Characterizing and understanding ATP dynamics provide valuable mechanistic insight into processes that range from neurotransmission to the chemotaxis of immune cells. Therefore, we require the methodology to interrogate both temporal and spatial components of ATP dynamics from the subcellular to the organismal levels in live specimens. Over the last several decades, a number of molecular probes that are specific to ATP have been developed. These probes have been combined with imaging approaches, particularly optical microscopy, to enable qualitative and quantitative detection of this critical molecule. In this review, we survey current examples of technologies available for visualizing ATP in living cells, and identify areas where new tools and approaches are needed to expand our capabilities.
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Affiliation(s)
- Megha Rajendran
- Department of Chemistry, Purdue University, 560 Oval Drive, Box 68, West Lafayette, Indiana 47907; and
| | - Eric Dane
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, 77 Massachusetts Avenue, 76-211, Cambridge, Massachusetts 02139
| | - Jason Conley
- Department of Chemistry, Purdue University, 560 Oval Drive, Box 68, West Lafayette, Indiana 47907; and
| | - Mathew Tantama
- Department of Chemistry, Purdue University, 560 Oval Drive, Box 68, West Lafayette, Indiana 47907; and
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21
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Magnetic Resonance Imaging of Phosphocreatine and Determination of BOLD Kinetics in Lower Extremity Muscles using a Dual-Frequency Coil Array. Sci Rep 2016; 6:30568. [PMID: 27465636 PMCID: PMC4964597 DOI: 10.1038/srep30568] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 07/01/2016] [Indexed: 01/17/2023] Open
Abstract
Magnetic resonance imaging (MRI) provides the unique ability to study metabolic and microvasculature functions in skeletal muscle using phosphorus and proton measurements. However, the low sensitivity of these techniques can make it difficult to capture dynamic muscle activity due to the temporal resolution required for kinetic measurements during and after exercise tasks. Here, we report the design of a dual-nuclei coil array that enables proton and phosphorus MRI of the human lower extremities with high spatial and temporal resolution. We developed an array with whole-volume coverage of the calf and a phosphorus signal-to-noise ratio of more than double that of a birdcage coil in the gastrocnemius muscles. This enabled the local assessment of phosphocreatine recovery kinetics following a plantar flexion exercise using an efficient sampling scheme with a 6 s temporal resolution. The integrated proton array demonstrated image quality approximately equal to that of a clinical state-of-the-art knee coil, which enabled fat quantification and dynamic blood oxygen level-dependent measurements that reflect microvasculature function. The developed array and time-efficient pulse sequences were combined to create a localized assessment of calf metabolism using phosphorus measurements and vasculature function using proton measurements, which could provide new insights into muscle function.
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22
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Pouymayou B, Buehler T, Kreis R, Boesch C. Test-retest analysis of multiple 31 P magnetization exchange pathways using asymmetric adiabatic inversion. Magn Reson Med 2016; 78:33-39. [PMID: 27455454 DOI: 10.1002/mrm.26337] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2016] [Revised: 05/31/2016] [Accepted: 06/17/2016] [Indexed: 01/08/2023]
Abstract
PURPOSE A 31 P-MR inversion transfer (IT) method with a short adiabatic inversion pulse is proposed and its test-retest reliability was evaluated for two spectral fitting strategies. METHODS Assessment in a test-retest design (3 Tesla, vastus muscles, 12 healthy volunteers, 14 inversion times, 22 ms asymmetric adiabatic inversion pulse, adiabatic excitation); spectral fitting in Fitting Tool for Interrelated Arrays of Datasets (FitAID) and Java Magnetic Resonance User Interface (jMRUI); least squares solution of the Bloch-McConnell-Solomon matrix formalism including all 14 measured time-points with equal weighting. RESULTS The cohort averages of k[PCr→γ-ATP] (phosphocreatine, PCr; adenosine triphosphate, ATP) are 0.246 ± 0.050s-1 versus 0.254 ± 0.050s-1 , and k[Pi→γ-ATP] 0.086 ± 0.033s-1 versus 0.066 ± 0.034s-1 (average ± standard deviation, jMRUI versus FitAID). Coefficients of variation of the differences between test and retest are lowest (9.5%) for k[PCr→γ-ATP] fitted in FitAID, larger (15.2%) for the fit in jMRUI, and considerably larger for k[Pi→γ-ATP] fitted in FitAID (43.4%) or jMRUI (47.9%). The beginning of the IT effect can be observed with magnetizations above 92% for noninverted lines while inversion of the ATP resonances is better than -72%. CONCLUSION The performance of the asymmetric adiabatic pulse allows an accurate observation of IT effects even in the early phase; the least squares fit of the Bloch-McConnell-Solomon matrix formalism is robust; and the type of spectral fitting can influence the results significantly. Magn Reson Med 78:33-39, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Bertrand Pouymayou
- Department of Clinical Research and Department of Radiology, University of Bern, Switzerland.,Graduate School for Cellular and Biomedical Sciences, University of Bern, Bern, Switzerland
| | - Tania Buehler
- Department of Clinical Research and Department of Radiology, University of Bern, Switzerland
| | - Roland Kreis
- Department of Clinical Research and Department of Radiology, University of Bern, Switzerland
| | - Chris Boesch
- Department of Clinical Research and Department of Radiology, University of Bern, Switzerland
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Li M, Chen F, Wang H, Wu W, Zhang X, Tian C, Yu H, Liu R, Zhu B, Zhang B, Dai Z. Non-invasive assessment of phosphate metabolism and oxidative capacity in working skeletal muscle in healthy young Chinese volunteers using (31)P Magnetic Resonance Spectroscopy. PeerJ 2016; 4:e2259. [PMID: 27547565 PMCID: PMC4963215 DOI: 10.7717/peerj.2259] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 06/24/2016] [Indexed: 11/25/2022] Open
Abstract
Background. Generally, males display greater strength and muscle capacity than females while performing a task. Muscle biopsy is regarded as the reference method of evaluating muscle functions; however, it is invasive and has sampling errors, and is not practical for longitudinal studies and dynamic measurement during excise. In this study, we built an in-house force control and gauge system for quantitatively applying force to quadriceps while the subjects underwent 31P Magnetic Resonance Spectroscopy (31P-MRS); our aim was to investigate if there is a sex difference of phosphate metabolite change in working muscles in young heathy Chinese volunteers. Methods. Volunteers performed knee-extending excises using a force control and gauge system while lying prone in a Philips 3T Magnetic Resonance (MR) scanner. The 31P-MRS coil was firmly placed under the middle of the quadriceps . 31P-MRS measurements of inorganic phosphate (Pi), phosphocreatine (PCr) and adenosine triphosphate (ATP) were acquired from quadriceps while subjects were in a state of pre-, during- and post-exercise. The PCr, Pi, PCr/Pi, PCr/ATP, pH, work/energy cost ratio (WE), kPCr and oxidative capacity were compared between males and females. Results. A total of 17 volunteers underwent the study. Males: N = 10, age = 23.30 ± 1.25years; females: N = 7, age = 23.57 ± 0.79 years. In this study, males had significantly greater WE (16.33 ± 6.46 vs. 7.82 ± 2.16, p = 0.002) than females. Among PCr, Pi, PCr/Pi, PCr/ATP, pH, kPCr and oxidative capacity at different exercise status, only PCr/Pi (during-exercise, males = 5.630 ± 1.647, females = 4.014 ± 1.298, p = 0.047), PCr/ATP (during-exercise, males =1.273 ± 0.219, females = 1.523 ± 0.167, p = 0.025), and ATP (post-exercise, males = 24.469 ± 3.911 mmol/kg, females = 18.353 ± 4.818 mmol/kg, p = 0.035) had significant sex differences. Males had significantly greater PCr/Pi, but less PCr/ATP than females during exercise, suggesting males had higher energy transfer efficiency than females. At the post-exercise status, the recovery of PCr did not show sex difference. Conclusions. Our in-house force control and gauge system quantitatively applied force during the exercise for 31P-MRS experiments, and a sex difference of higher energy transfer efficiency and WE was detected in males with mild loaded exercising quadriceps. This noninvasive technology allows us to further study and understand the sex difference of high energy phosphate metabolism in the future.
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Affiliation(s)
- Ming Li
- Department of Radiology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Fei Chen
- Department of Radiology, Affiliated Yancheng Hospital, School of Medicine, Southeast University, Yancheng, Jiangsu, China
| | - Huiting Wang
- Department of Radiology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Wenbo Wu
- Department of Radiology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Xin Zhang
- Department of Radiology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Chuanshuai Tian
- Department of Radiology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Haiping Yu
- Department of Radiology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Renyuan Liu
- Department of Neurology, Drum Tower Hospital, Affiliated to Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Bin Zhu
- Department of Radiology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Bing Zhang
- Department of Radiology, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing, Jiangsu, China
| | - Zhenyu Dai
- Department of Radiology, Affiliated Yancheng Hospital, School of Medicine, Southeast University, Yancheng, Jiangsu, China
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Ren J, Sherry AD, Malloy CR. Band inversion amplifies 31 P- 31 P nuclear overhauser effects: Relaxation mechanism and dynamic behavior of ATP in the human brain by 31 P MRS at 7 T. Magn Reson Med 2016; 77:1409-1418. [PMID: 27060982 DOI: 10.1002/mrm.26236] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 02/22/2016] [Accepted: 03/14/2016] [Indexed: 01/07/2023]
Abstract
PURPOSE To develop an improved method to measure the 31 P nuclear Overhauser effect (NOE) for evaluation of adenosine triphosphate (ATP) dynamics in terms of correlation time (τc ), and contribution of dipole-dipole (DD) and chemical shift anisotropy (CSA) mechanisms to T1 relaxation of ATP in human brain. METHODS The NOE of ATP in human brain was evaluated by monitoring changes in magnetization in the β-ATP signal following a band inversion of all downfield 31 P resonances. The magnetization changes observed were analyzed using the Bloch-McConnell-Solomon formulation to evaluate the relaxation and motion dynamic parameters that describe interactions of ATP with cellular solids in human brain tissue. RESULTS The maximal transient NOE, observed as a reduction in the β-ATP signal, was 24 ± 2% upon band inversion of γ- and α-ATP, which is 2-3-fold higher than achievable by frequency-selective inversion of either γ- or α-ATP. The rate of 31 P-31 P cross relaxation (0.21 ± 0.02 s-1 ) led to a τc value of (9.1 ± 0.8) × 10-8 s for ATP in human brain. The T1 relaxation of β-ATP is dominated by CSA over the DD mechanism (60%: 40%). CONCLUSIONS The band inversion method proved effective in amplifying 31 P NOE, and thus facilitating ATP τc and relaxation measurements. This technique renders ATP a potentially useful reporter molecule for cellular environments. Magn Reson Med 77:1409-1418, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
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Affiliation(s)
- Jimin Ren
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, 75390.,Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, 75390
| | - A Dean Sherry
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, 75390.,Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, 75390.,Department of Chemistry, University of Texas at Dallas, Richardson, TX, 75080
| | - Craig R Malloy
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX, 75390.,Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, 75390.,Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX, 75390.,VA North Texas Health Care System, Dallas, TX, 75216
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Sleigh A, Savage DB, Williams GB, Porter D, Carpenter TA, Brindle KM, Kemp GJ. 31P magnetization transfer measurements of Pi→ATP flux in exercising human muscle. J Appl Physiol (1985) 2016; 120:649-56. [PMID: 26744504 PMCID: PMC4796179 DOI: 10.1152/japplphysiol.00871.2015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 01/02/2016] [Indexed: 11/22/2022] Open
Abstract
Fundamental criticisms have been made over the use of (31)P magnetic resonance spectroscopy (MRS) magnetization transfer estimates of inorganic phosphate (Pi)→ATP flux (VPi-ATP) in human resting skeletal muscle for assessing mitochondrial function. Although the discrepancy in the magnitude of VPi-ATP is now acknowledged, little is known about its metabolic determinants. Here we use a novel protocol to measure VPi-ATP in human exercising muscle for the first time. Steady-state VPi-ATP was measured at rest and over a range of exercise intensities and compared with suprabasal oxidative ATP synthesis rates estimated from the initial rates of postexercise phosphocreatine resynthesis (VATP). We define a surplus Pi→ATP flux as the difference between VPi-ATP and VATP. The coupled reactions catalyzed by the glycolytic enzymes GAPDH and phosphoglycerate kinase (PGK) have been shown to catalyze measurable exchange between ATP and Pi in some systems and have been suggested to be responsible for this surplus flux. Surplus VPi-ATP did not change between rest and exercise, even though the concentrations of Pi and ADP, which are substrates for GAPDH and PGK, respectively, increased as expected. However, involvement of these enzymes is suggested by correlations between absolute and surplus Pi→ATP flux, both at rest and during exercise, and the intensity of the phosphomonoester peak in the (31)P NMR spectrum. This peak includes contributions from sugar phosphates in the glycolytic pathway, and changes in its intensity may indicate changes in downstream glycolytic intermediates, including 3-phosphoglycerate, which has been shown to influence the exchange between ATP and Pi catalyzed by GAPDH and PGK.
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Affiliation(s)
- Alison Sleigh
- Wolfson Brain Imaging Centre, University of Cambridge School of Clinical Medicine, Cambridge Biomedical Campus, United Kingdom; National Institute for Health Research/Wellcome Trust Clinical Research Facility at Cambridge University Hospitals NHS Foundation Trust, Cambridge Biomedical Campus, United Kingdom;
| | - David B Savage
- University of Cambridge Metabolic Research Laboratories, Wellcome Trust-Medical Research Council Institute of Metabolic Science, Cambridge Biomedical Campus, United Kingdom
| | - Guy B Williams
- Wolfson Brain Imaging Centre, University of Cambridge School of Clinical Medicine, Cambridge Biomedical Campus, United Kingdom
| | - David Porter
- Fraunhofer MEVIS, Institute for Medical Image Computing, Bremen, Germany
| | - T Adrian Carpenter
- Wolfson Brain Imaging Centre, University of Cambridge School of Clinical Medicine, Cambridge Biomedical Campus, United Kingdom
| | - Kevin M Brindle
- Department of Biochemistry, University of Cambridge, United Kingdom; Cancer Research UK Cambridge Institute, Li Ka Shing Centre, University of Cambridge, Cambridge Biomedical Campus, United Kingdom
| | - Graham J Kemp
- Magnetic Resonance and Image Analysis Research Centre, University of Liverpool, United Kingdom; and Department of Musculoskeletal Biology and MRC - Arthritis Research UK Centre for Integrated research into Musculoskeletal Ageing, Institute of Ageing and Chronic Disease, University of Liverpool, United Kingdom
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26
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Tušek Jelenc M, Chmelík M, Bogner W, Krššák M, Trattnig S, Valkovič L. Feasibility and repeatability of localized (31) P-MRS four-angle saturation transfer (FAST) of the human gastrocnemius muscle using a surface coil at 7 T. NMR IN BIOMEDICINE 2016; 29:57-65. [PMID: 26684051 PMCID: PMC4833172 DOI: 10.1002/nbm.3445] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Revised: 09/28/2015] [Accepted: 10/20/2015] [Indexed: 05/11/2023]
Abstract
Phosphorus ((31) P) MRS, combined with saturation transfer (ST), provides non-invasive insight into muscle energy metabolism. However, even at 7 T, the standard ST method with T1 (app) measured by inversion recovery takes about 10 min, making it impractical for dynamic examinations. An alternative method, i.e. four-angle saturation transfer (FAST), can shorten the examination time. The aim of this study was to test the feasibility, repeatability, and possible time resolution of the localized FAST technique measurement on an ultra-high-field MR system, to accelerate the measurement of both Pi -to-ATP and PCr-to-ATP reaction rates in the human gastrocnemius muscle and to test the feasibility of using the FAST method for dynamic measurements. We measured the exchange rates and metabolic fluxes in the gastrocnemius muscle of eight healthy subjects at 7 T with the depth-resolved surface coil MRS (DRESS)-localized FAST method. For comparison, a standard ST localized method was also used. The measurement time for the localized FAST experiment was 3.5 min compared with the 10 min for the standard localized ST experiment. In addition, in five healthy volunteers, Pi -to-ATP and PCr-to-ATP metabolic fluxes were measured in the gastrocnemius muscle at rest and during plantar flexion by the DRESS-localized FAST method. The repeatability of PCr-to-ATP and Pi -to-ATP exchange rate constants, determined by the slab-selective localized FAST method at 7 T, is high, as the coefficients of variation remained below 20%, and the results of the exchange rates measured with the FAST method are comparable to those measured with standard ST. During physical activity, the PCr-to-ATP metabolic flux decreased (from FCK = 8.21 ± 1.15 mM s(-1) to FCK = 3.86 ± 1.38 mM s(-1) ) and the Pi -to-ATP flux increased (from FATP = 0.43 ± 0.14 mM s(-1) to FATP = 0.74 ± 0.13 mM s(-1) ). In conclusion, we could demonstrate that measurements in the gastrocnemius muscle are feasible at rest and are short enough to be used during exercise with the DRESS-localized FAST method at 7 T.
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Affiliation(s)
- Marjeta Tušek Jelenc
- High Field MR Centre, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
- Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria
| | - Marek Chmelík
- High Field MR Centre, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
- Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria
| | - Wolfgang Bogner
- High Field MR Centre, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
- Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria
| | - Martin Krššák
- High Field MR Centre, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
- Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria
- Division of Endocrinology and Metabolism, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Siegfried Trattnig
- High Field MR Centre, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
- Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria
| | - Ladislav Valkovič
- High Field MR Centre, Department of Biomedical Imaging and Image-Guided Therapy, Medical University of Vienna, Vienna, Austria
- Christian Doppler Laboratory for Clinical Molecular MR Imaging, Vienna, Austria
- Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovakia
- Oxford Centre for Clinical MR Research (OCMR), University of Oxford, United Kingdom
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Ren J, Sherry AD, Malloy CR. Amplification of the effects of magnetization exchange by (31) P band inversion for measuring adenosine triphosphate synthesis rates in human skeletal muscle. Magn Reson Med 2015; 74:1505-14. [PMID: 25469992 PMCID: PMC4792267 DOI: 10.1002/mrm.25514] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 09/23/2014] [Accepted: 10/09/2014] [Indexed: 01/06/2023]
Abstract
PURPOSE The goal of this study was to amplify the effects of magnetization exchange between γ-adenosine triphosphate (ATP) and inorganic phosphate (Pi) for evaluation of ATP synthesis rates in human skeletal muscle. METHODS The strategy works by simultaneously inverting the (31) P resonances of phosphocreatine (PCr) and ATP using a wide bandwidth, adiabatic inversion radiofrequency pulse followed by observing dynamic changes in intensity of the noninverted Pi signal versus the delay time between the inversion and observation pulses. This band inversion technique significantly delays recovery of γ-ATP magnetization; consequently, the exchange reaction, Pi ↔ γ-ATP, is readily detected and easily analyzed. RESULTS The ATP synthesis rate measured from high-quality spectral data using this method was 0.073 ± 0.011 s(-1) in resting human skeletal muscle (N = 10). The T1 of Pi was 6.93 ± 1.90 s, consistent with the intrinsic T1 of Pi at this field. The apparent T1 of γ-ATP was 4.07 ± 0.32 s, about two-fold longer than its intrinsic T1 due to storage of magnetization in PCr. CONCLUSION Band inversion provides an effective method to amplify the effects of magnetization transfer between γ-ATP and Pi. The resulting data can be easily analyzed to obtain the ATP synthesis rate using a two-site exchange model.
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Affiliation(s)
- Jimin Ren
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX75390
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX75390
| | - A. Dean Sherry
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX75390
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX75390
- Department of Chemistry, University of Texas at Dallas, Richardson, TX75080
| | - Craig R. Malloy
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX75390
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX75390
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX75390
- VA North Texas Health Care System, Dallas, TX75216
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Ren J, Sherry AD, Malloy CR. (31)P-MRS of healthy human brain: ATP synthesis, metabolite concentrations, pH, and T1 relaxation times. NMR IN BIOMEDICINE 2015; 28:1455-62. [PMID: 26404723 PMCID: PMC4772768 DOI: 10.1002/nbm.3384] [Citation(s) in RCA: 69] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2015] [Revised: 07/22/2015] [Accepted: 07/24/2015] [Indexed: 05/18/2023]
Abstract
The conventional method for measuring brain ATP synthesis is (31)P saturation transfer (ST), a technique typically dependent on prolonged pre-saturation with γ-ATP. In this study, ATP synthesis rate in resting human brain is evaluated using EBIT (exchange kinetics by band inversion transfer), a technique based on slow recovery of γ-ATP magnetization in the absence of B1 field following co-inversion of PCr and ATP resonances with a short adiabatic pulse. The unidirectional rate constant for the Pi → γ-ATP reaction is 0.21 ± 0.04 s(-1) and the ATP synthesis rate is 9.9 ± 2.1 mmol min(-1) kg(-1) in human brain (n = 12 subjects), consistent with the results by ST. Therefore, EBIT could be a useful alternative to ST in studying brain energy metabolism in normal physiology and under pathological conditions. In addition to ATP synthesis, all detectable (31)P signals are analyzed to determine the brain concentration of phosphorus metabolites, including UDPG at around 10 ppm, a previously reported resonance in liver tissues and now confirmed in human brain. Inversion recovery measurements indicate that UDPG, like its diphosphate analogue NAD, has apparent T1 shorter than that of monophosphates (Pi, PMEs, and PDEs) but longer than that of triphosphate ATP, highlighting the significance of the (31)P-(31)P dipolar mechanism in T1 relaxation of polyphosphates. Another interesting finding is the observation of approximately 40% shorter T1 for intracellular Pi relative to extracellular Pi, attributed to the modulation by the intracellular phosphoryl exchange reaction Pi ↔ γ-ATP. The sufficiently separated intra- and extracellular Pi signals also permit the distinction of pH between intra- and extracellular environments (pH 7.0 versus pH 7.4). In summary, quantitative (31)P MRS in combination with ATP synthesis, pH, and T1 relaxation measurements may offer a promising tool to detect biochemical alterations at early stages of brain dysfunctions and diseases.
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Affiliation(s)
- Jimin Ren
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX 75390
| | - A. Dean Sherry
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Department of Chemistry, University of Texas at Dallas, Richardson, TX 75080
| | - Craig R. Malloy
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX 75390
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390
- VA North Texas Health Care System, Dallas, TX 75216
- To whom correspondence should be addressed: Craig R. Malloy, 5323 Harry Hines Blvd, NE4.2, Dallas, Texas 75390-8568, USA, (214) 645-2722,
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30
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Carpenter KLH, Jalloh I, Hutchinson PJ. Glycolysis and the significance of lactate in traumatic brain injury. Front Neurosci 2015; 9:112. [PMID: 25904838 PMCID: PMC4389375 DOI: 10.3389/fnins.2015.00112] [Citation(s) in RCA: 101] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2014] [Accepted: 03/16/2015] [Indexed: 01/19/2023] Open
Abstract
In traumatic brain injury (TBI) patients, elevation of the brain extracellular lactate concentration and the lactate/pyruvate ratio are well-recognized, and are associated statistically with unfavorable clinical outcome. Brain extracellular lactate was conventionally regarded as a waste product of glucose, when glucose is metabolized via glycolysis (Embden-Meyerhof-Parnas pathway) to pyruvate, followed by conversion to lactate by the action of lactate dehydrogenase, and export of lactate into the extracellular fluid. In TBI, glycolytic lactate is ascribed to hypoxia or mitochondrial dysfunction, although the precise nature of the latter is incompletely understood. Seemingly in contrast to lactate's association with unfavorable outcome is a growing body of evidence that lactate can be beneficial. The idea that the brain can utilize lactate by feeding into the tricarboxylic acid (TCA) cycle of neurons, first published two decades ago, has become known as the astrocyte-neuron lactate shuttle hypothesis. Direct evidence of brain utilization of lactate was first obtained 5 years ago in a cerebral microdialysis study in TBI patients, where administration of (13)C-labeled lactate via the microdialysis catheter and simultaneous collection of the emerging microdialysates, with (13)C NMR analysis, revealed (13)C labeling in glutamine consistent with lactate utilization via the TCA cycle. This suggests that where neurons are too damaged to utilize the lactate produced from glucose by astrocytes, i.e., uncoupling of neuronal and glial metabolism, high extracellular levels of lactate would accumulate, explaining the association between high lactate and poor outcome. Recently, an intravenous exogenous lactate supplementation study in TBI patients revealed evidence for a beneficial effect judged by surrogate endpoints. Here we review the current state of knowledge about glycolysis and lactate in TBI, how it can be measured in patients, and whether it can be modulated to achieve better clinical outcome.
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Affiliation(s)
- Keri L H Carpenter
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge Cambridge, UK ; Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge Cambridge, UK
| | - Ibrahim Jalloh
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge Cambridge, UK
| | - Peter J Hutchinson
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge Cambridge, UK ; Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge Cambridge, UK
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Carpenter KLH, Czosnyka M, Jalloh I, Newcombe VFJ, Helmy A, Shannon RJ, Budohoski KP, Kolias AG, Kirkpatrick PJ, Carpenter TA, Menon DK, Hutchinson PJ. Systemic, local, and imaging biomarkers of brain injury: more needed, and better use of those already established? Front Neurol 2015; 6:26. [PMID: 25741315 PMCID: PMC4332345 DOI: 10.3389/fneur.2015.00026] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2014] [Accepted: 01/30/2015] [Indexed: 02/02/2023] Open
Abstract
Much progress has been made over the past two decades in the treatment of severe acute brain injury, including traumatic brain injury and subarachnoid hemorrhage, resulting in a higher proportion of patients surviving with better outcomes. This has arisen from a combination of factors. These include improvements in procedures at the scene (pre-hospital) and in the hospital emergency department, advances in neuromonitoring in the intensive care unit, both continuously at the bedside and intermittently in scans, evolution and refinement of protocol-driven therapy for better management of patients, and advances in surgical procedures and rehabilitation. Nevertheless, many patients still experience varying degrees of long-term disabilities post-injury with consequent demands on carers and resources, and there is room for improvement. Biomarkers are a key aspect of neuromonitoring. A broad definition of a biomarker is any observable feature that can be used to inform on the state of the patient, e.g., a molecular species, a feature on a scan, or a monitoring characteristic, e.g., cerebrovascular pressure reactivity index. Biomarkers are usually quantitative measures, which can be utilized in diagnosis and monitoring of response to treatment. They are thus crucial to the development of therapies and may be utilized as surrogate endpoints in Phase II clinical trials. To date, there is no specific drug treatment for acute brain injury, and many seemingly promising agents emerging from pre-clinical animal models have failed in clinical trials. Large Phase III studies of clinical outcomes are costly, consuming time and resources. It is therefore important that adequate Phase II clinical studies with informative surrogate endpoints are performed employing appropriate biomarkers. In this article, we review some of the available systemic, local, and imaging biomarkers and technologies relevant in acute brain injury patients, and highlight gaps in the current state of knowledge.
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Affiliation(s)
- Keri L. H. Carpenter
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK,Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK,*Correspondence: Keri L. H. Carpenter, Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Box 167, Cambridge Biomedical Campus, Cambridge CB2 0QQ, UK e-mail:
| | - Marek Czosnyka
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Ibrahim Jalloh
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Virginia F. J. Newcombe
- Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK,Division of Anaesthesia, Department of Medicine, University of Cambridge, Cambridge, UK
| | - Adel Helmy
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Richard J. Shannon
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Karol P. Budohoski
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Angelos G. Kolias
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Peter J. Kirkpatrick
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Thomas Adrian Carpenter
- Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - David K. Menon
- Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK,Division of Anaesthesia, Department of Medicine, University of Cambridge, Cambridge, UK
| | - Peter J. Hutchinson
- Division of Neurosurgery, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK,Wolfson Brain Imaging Centre, Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
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Buehler T, Kreis R, Boesch C. Comparison of (31)P saturation and inversion magnetization transfer in human liver and skeletal muscle using a clinical MR system and surface coils. NMR IN BIOMEDICINE 2015; 28:188-199. [PMID: 25483778 DOI: 10.1002/nbm.3242] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 11/07/2014] [Accepted: 11/10/2014] [Indexed: 06/04/2023]
Abstract
(31)P MRS magnetization transfer ((31)P-MT) experiments allow the estimation of exchange rates of biochemical reactions, such as the creatine kinase equilibrium and adenosine triphosphate (ATP) synthesis. Although various (31)P-MT methods have been successfully used on isolated organs or animals, their application on humans in clinical scanners poses specific challenges. This study compared two major (31)P-MT methods on a clinical MR system using heteronuclear surface coils. Although saturation transfer (ST) is the most commonly used (31)P-MT method, sequences such as inversion transfer (IT) with short pulses might be better suited for the specific hardware and software limitations of a clinical scanner. In addition, small NMR-undetectable metabolite pools can transfer MT to NMR-visible pools during long saturation pulses, which is prevented with short pulses. (31)P-MT sequences were adapted for limited pulse length, for heteronuclear transmit-receive surface coils with inhomogeneous B1 , for the need for volume selection and for the inherently low signal-to-noise ratio (SNR) on a clinical 3-T MR system. The ST and IT sequences were applied to skeletal muscle and liver in 10 healthy volunteers. Monte-Carlo simulations were used to evaluate the behavior of the IT measurements with increasing imperfections. In skeletal muscle of the thigh, ATP synthesis resulted in forward reaction constants (k) of 0.074 ± 0.022 s(-1) (ST) and 0.137 ± 0.042 s(-1) (IT), whereas the creatine kinase reaction yielded 0.459 ± 0.089 s(-1) (IT). In the liver, ATP synthesis resulted in k = 0.267 ± 0.106 s(-1) (ST), whereas the IT experiment yielded no consistent results. ST results were close to literature values; however, the IT results were either much larger than the corresponding ST values and/or were widely scattered. To summarize, ST and IT experiments can both be implemented on a clinical body scanner with heteronuclear transmit-receive surface coils; however, ST results are much more robust against experimental imperfections than the current implementation of IT.
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Affiliation(s)
- Tania Buehler
- Departments of Clinical Research and Radiology, University of Bern, Switzerland
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Ectopic lipid storage in non-alcoholic fatty liver disease is not mediated by impaired mitochondrial oxidative capacity in skeletal muscle. Clin Sci (Lond) 2014; 127:655-63. [PMID: 24738611 DOI: 10.1042/cs20130404] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Non-alcoholic fatty liver disease (NAFLD), characterized by lipid deposition within the liver [intrahepatocellular lipid (IHCL)], is associated with insulin resistance and the metabolic syndrome (MS). It has been suggested that impaired skeletal muscle mitochondrial function may contribute to ectopic lipid deposition, and the associated MS, by altering post-prandial energy storage. To test this hypothesis, we performed a cross-sectional study of 17 patients with NAFLD [mean±S.D.; age, 45±11 years; body mass index (BMI), 31.6±3.4 kg/m2] and 18 age- and BMI-matched healthy controls (age, 44±11 years; BMI, 30.5±5.2 kg/m2). We determined body composition by MRI, IHCL and intramyocellular (soleus and tibialis anterior) lipids (IMCLs) by proton magnetic resonance spectroscopy (1H-MRS) and skeletal muscle mitochondrial function by dynamic phosphorus magnetic resonance spectroscopy (31P-MRS) of quadriceps muscle. Although matched for BMI and total adiposity, after statistical adjustment for gender, patients with NAFLD (defined by IHCL ≥ 5.5%) had higher IHCLs (25±16% compared with 2±2%; P<0.0005) and a higher prevalence of the MS (76% compared with 28%) compared with healthy controls. Despite this, the visceral fat/subcutaneous fat ratio, IMCLs and muscle mitochondrial function were similar between the NAFLD and control groups, with no significant difference in the rate constants of post-exercise phosphocreatine (PCr) recovery (1.55±0.4 compared with 1.51±0.4 min-1), a measure of muscle mitochondrial function. In conclusion, impaired muscle mitochondrial function does not seem to underlie ectopic lipid deposition, or the accompanying features of the MS, in patients with NAFLD.
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Parasoglou P, Xia D, Regatte RR. Feasibility of mapping unidirectional Pi-to-ATP fluxes in muscles of the lower leg at 7.0 Tesla. Magn Reson Med 2014; 74:225-230. [PMID: 25078605 DOI: 10.1002/mrm.25388] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2014] [Revised: 06/10/2014] [Accepted: 07/05/2014] [Indexed: 12/16/2022]
Abstract
PURPOSE To assess the feasibility of mapping the kinetics and unidirectional fluxes of inorganic phosphate (Pi) to adenosine triphosphate (ATP) reactions in the entire volume of the lower leg muscles using a three-dimensional saturation transfer (ST) phosphorus (31 P) imaging sequence. THEORY AND METHODS We imaged the lower leg muscles of five healthy subjects at 7.0 Tesla. The total experimental time was 45 min. We quantified muscle-specific forward reaction rate constants (k'f ) and metabolic fluxes (Vf ) of the Pi-to-ATP reaction in the tibialis anterior, the gastrocnemius, and the soleus. RESULTS In the tibialis anterior, k'f and Vf were 0.11 s-1 ± 0.03 (mean ± standard deviation) and 0.34 mM s-1 ± 0.10, respectively. In the gastrocnemius, k'f was 0.11 s-1 ± 0.04 and Vf was 0.37 mM s-1 ± 0.11, while in the soleus muscle k'f was 0.10 s-1 ± 0.02 and Vf was 0.36 mM s-1 ± 0.14. CONCLUSION Our results suggest that mapping the kinetics and unidirectional fluxes from Pi-to-ATP in both the anterior and posterior muscles of the lower leg is feasible at ultra-high field and may provide useful insights for the study of insulin resistance, diabetes and aging. Magn Reson Med 74:225-230, 2015. © 2014 Wiley Periodicals, Inc.
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Affiliation(s)
- Prodromos Parasoglou
- Quantitative Multinuclear Musculoskeletal Imaging Group (QMMIG), Department of Radiology, Center for Biomedical Imaging, New York University Langone Medical Center, New York, New York, USA
| | - Ding Xia
- Quantitative Multinuclear Musculoskeletal Imaging Group (QMMIG), Department of Radiology, Center for Biomedical Imaging, New York University Langone Medical Center, New York, New York, USA
| | - Ravinder R Regatte
- Quantitative Multinuclear Musculoskeletal Imaging Group (QMMIG), Department of Radiology, Center for Biomedical Imaging, New York University Langone Medical Center, New York, New York, USA
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Ren J, Yang B, Sherry AD, Malloy CR. Exchange kinetics by inversion transfer: integrated analysis of the phosphorus metabolite kinetic exchanges in resting human skeletal muscle at 7 T. Magn Reson Med 2014; 73:1359-69. [PMID: 24733433 DOI: 10.1002/mrm.25256] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Revised: 03/06/2014] [Accepted: 03/26/2014] [Indexed: 01/06/2023]
Abstract
PURPOSE To develop an inversion pulse-based, chemical exchange saturation transfer-like method for detection of (31) P magnetization exchanges among all nuclear magnetic resonance visible metabolites suitable for providing an integrated kinetic analysis of phosphorus exchange reactions in vivo. METHODS The exchange kinetics by inversion transfer (EKIT) sequence includes application of a frequency-selective inversion pulse arrayed over the range of relevant (31) P frequencies, followed by a constant delay and a hard readout pulse. A series of EKIT spectra, each given by a plot of Z-magnetization for each metabolite of interest versus frequency of the inversion pulse, can be generated from this single data set. RESULTS EKIT spectra reflect chemical exchange due to known biochemical reactions, cross-relaxation effects, and relayed magnetization transfers due to both processes. The rate constants derived from EKIT data collected on resting human skeletal muscle were: ATP synthesis via ATP synthase (0.050 ± 0.016 s(-1) ), ATP synthesis via creatine kinase (0.264 ± 0.023 s(-1) ), and cross-relaxation between neighboring spin pairs within ATP (0.164 ± 0.022 s(-1) ). CONCLUSION EKIT provides a simple, alternative method to detect chemical exchange, cross relaxation, and relayed magnetization transfer effects in human skeletal muscle at 7 T.
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Affiliation(s)
- Jimin Ren
- Advanced Imaging Research Center, University of Texas Southwestern Medical Center, Dallas, Texas, USA; Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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Prompers JJ, Wessels B, Kemp GJ, Nicolay K. MITOCHONDRIA: investigation of in vivo muscle mitochondrial function by 31P magnetic resonance spectroscopy. Int J Biochem Cell Biol 2014; 50:67-72. [PMID: 24569118 DOI: 10.1016/j.biocel.2014.02.014] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Revised: 02/06/2014] [Accepted: 02/16/2014] [Indexed: 01/06/2023]
Abstract
The most important function of mitochondria is the production of energy in the form of ATP. The socio-economic impact of human diseases that affect skeletal muscle mitochondrial function is growing, and improving their clinical management critically depends on the development of non-invasive assays to assess mitochondrial function and monitor the effects of interventions. 31P magnetic resonance spectroscopy provides two approaches that have been used to assess in vivo ATP synthesis in skeletal muscle: measuring Pi→ATP exchange flux using saturation transfer in resting muscle, and measuring phosphocreatine recovery kinetics after exercise. However, Pi→ATP exchange does not represent net mitochondrial ATP synthesis flux and has no simple relationship with mitochondrial function. Post-exercise phosphocreatine recovery kinetics, on the other hand, yield reliable measures of muscle mitochondrial capacity in vivo, whose ability to define the site of functional defects is enhanced by combination with other non-invasive techniques.
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Affiliation(s)
- Jeanine J Prompers
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands.
| | - Bart Wessels
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Graham J Kemp
- Department of Musculoskeletal Biology and Magnetic Resonance & Image Analysis Research Centre, University of Liverpool, UK
| | - Klaas Nicolay
- Biomedical NMR, Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
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Szendroedi J, Kaul K, Kloock L, Straßburger K, Schmid AI, Chmelik M, Kacerovsky M, Kacerovsky-Bielesz G, Prikoszovich T, Brehm A, Krssák M, Gruber S, Krebs M, Kautzky-Willer A, Moser E, Pacini G, Roden M. Lower fasting muscle mitochondrial activity relates to hepatic steatosis in humans. Diabetes Care 2014; 37:468-74. [PMID: 24026561 DOI: 10.2337/dc13-1359] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE Muscle insulin resistance has been implicated in the development of steatosis and dyslipidemia by changing the partitioning of postprandial substrate fluxes. Also, insulin resistance may be due to reduced mitochondrial function. We examined the association between mitochondrial activity, insulin sensitivity, and steatosis in a larger human population. RESEARCH DESIGN AND METHODS We analyzed muscle mitochondrial activity from ATP synthase flux (fATP) and ectopic lipids by multinuclei magnetic resonance spectroscopy from 113 volunteers with and without diabetes. Insulin sensitivity was assessed from M values using euglycemic-hyperinsulinemic clamps and/or from oral glucose insulin sensitivity (OGIS) using oral glucose tolerance tests. RESULTS Muscle fATP correlated negatively with hepatic lipid content and HbA1c. After model adjustment for study effects and other confounders, fATP showed a strong negative correlation with hepatic lipid content and a positive correlation with insulin sensitivity and fasting C-peptide. The negative correlation of muscle fATP with age, HbA1c, and plasma free fatty acids was weakened after adjustment. Body mass, muscle lipid contents, plasma lipoproteins, and triglycerides did not associate with fATP. CONCLUSIONS The association of impaired muscle mitochondrial activity with hepatic steatosis supports the concept of a close link between altered muscle and liver energy metabolism as early abnormalities promoting insulin resistance.
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Befroy DE, Perry RJ, Jain N, Dufour S, Cline GW, Trimmer JK, Brosnan J, Rothman DL, Petersen KF, Shulman GI. Direct assessment of hepatic mitochondrial oxidative and anaplerotic fluxes in humans using dynamic 13C magnetic resonance spectroscopy. Nat Med 2014; 20:98-102. [PMID: 24317120 PMCID: PMC3947269 DOI: 10.1038/nm.3415] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Accepted: 10/29/2013] [Indexed: 12/11/2022]
Abstract
Despite the central role of the liver in the regulation of glucose and lipid metabolism, there are currently no methods to directly assess hepatic oxidative metabolism in humans in vivo. By using a new (13)C-labeling strategy in combination with (13)C magnetic resonance spectroscopy, we show that rates of mitochondrial oxidation and anaplerosis in human liver can be directly determined noninvasively. Using this approach, we found the mean rates of hepatic tricarboxylic acid (TCA) cycle flux (VTCA) and anaplerotic flux (VANA) to be 0.43 ± 0.04 μmol g(-1) min(-1) and 0.60 ± 0.11 μmol g(-1) min(-1), respectively, in twelve healthy, lean individuals. We also found the VANA/VTCA ratio to be 1.39 ± 0.22, which is severalfold lower than recently published estimates using an indirect approach. This method will be useful for understanding the pathogenesis of nonalcoholic fatty liver disease and type 2 diabetes, as well as for assessing the effectiveness of new therapies targeting these pathways in humans.
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Affiliation(s)
- Douglas E Befroy
- 1] Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, Connecticut, USA. [2] Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA. [3]
| | - Rachel J Perry
- 1] Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA. [2] Department of Cellular & Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut, USA. [3]
| | - Nimit Jain
- Department of Biomedical Engineering, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Sylvie Dufour
- Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Gary W Cline
- Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | | | | | - Douglas L Rothman
- 1] Department of Diagnostic Radiology, Yale University School of Medicine, New Haven, Connecticut, USA. [2] Department of Biomedical Engineering, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Kitt Falk Petersen
- 1] Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA. [2] Novo Nordisk Foundation Center for Basic Metabolic Research, Copenhagen, Denmark
| | - Gerald I Shulman
- 1] Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA. [2] Department of Cellular & Molecular Physiology, Yale University School of Medicine, New Haven, Connecticut, USA. [3] Howard Hughes Medical Institute, Yale University School of Medicine, New Haven, Connecticut, USA. [4] Novo Nordisk Foundation Center for Basic Metabolic Research, Copenhagen, Denmark
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Du F, Cooper A, Thida T, Sehovic S, Lukas SE, Cohen BM, Zhang X, Öngür D. In vivo evidence for cerebral bioenergetic abnormalities in schizophrenia measured using 31P magnetization transfer spectroscopy. JAMA Psychiatry 2014; 71:19-27. [PMID: 24196348 PMCID: PMC7461723 DOI: 10.1001/jamapsychiatry.2013.2287] [Citation(s) in RCA: 80] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
IMPORTANCE Abnormalities in neural activity and cerebral bioenergetics have been observed in schizophrenia (SZ). Further defining energy metabolism anomalies would provide crucial information about molecular mechanisms underlying SZ and may be valuable for developing novel treatment strategies. OBJECTIVE To investigate cerebral bioenergetics in SZ via measurement of creatine kinase activity using in vivo 31P magnetization transfer spectroscopy. DESIGN, SETTING, AND PARTICIPANTS Cross-sectional case-control study in the setting of clinical services and a brain imaging center of an academic psychiatric hospital. Twenty-six participants with chronic SZ (including a subgroup diagnosed as having schizoaffective disorder) and 26 age-matched and sex-matched healthy control subjects (25 usable magnetic resonance spectroscopy data sets from the latter). INTERVENTION 31P magnetization transfer spectroscopy. MAIN OUTCOMES AND MEASURES The primary outcome measure was the forward rate constant (k(f)) of the creatine kinase enzyme in the frontal lobe. We also collected independent measures of brain intracellular pH and steady-state metabolite ratios of high-energy phosphate-containing compounds (phosphocreatine and adenosine triphosphate [ATP]), inorganic phosphate, and the 2 membrane phospholipids phosphodiester and phosphomonoester. RESULTS A substantial (22%) and statistically significant (P = .003) reduction in creatine kinase kf was observed in SZ. In addition, intracellular pH was significantly reduced (7.00 in the SZ group vs 7.03 in the control group, P = .007) in this condition. The phosphocreatine to ATP ratio, inorganic phosphate to ATP ratio, and phosphomonoester to ATP ratio were not substantially altered in SZ, but a significant (P = .02) reduction was found in the phosphodiester to ATP ratio. The abnormalities were similar between SZ and schizoaffective disorder. CONCLUSIONS AND RELEVANCE Using a novel 31P magnetization transfer magnetic resonance spectroscopy approach, we provide direct and compelling evidence for a specific bioenergetic abnormality in SZ. Reduced kf of the creatine kinase enzyme is consistent with an abnormality in storage and use of brain energy. The intracellular pH reduction suggests a relative increase in the contribution of glycolysis to ATP synthesis, providing convergent evidence for bioenergetic abnormalities in SZ. The similar phosphocreatine to ATP ratios in SZ and healthy controls suggest that the underlying bioenergetics abnormality is not associated with change in this metabolite ratio.
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Affiliation(s)
- Fei Du
- McLean Hospital,Harvard Medical School,Corresponding Author: Fei Du, Ph.D.,
Brain Imaging Center, McLean Hospital, Department of Psychiatry, Harvard Medical
School, 115 Mill St, Belmont MA, 02478, Phone: (617) 855-3945,
; Dost
Öngür, M.D. Ph.D., Psychotic Disorders Division, McLean
Hospital, Department of Psychiatry, Harvard Medical School, 115 Mill St, Belmont
MA, 02478, Phone:(617) 855-3922,
| | | | | | | | | | | | - Xiaoliang Zhang
- Department of Radiology, University of California, San
Francisco
| | - Dost Öngür
- McLean Hospital,Harvard Medical School,Corresponding Author: Fei Du, Ph.D.,
Brain Imaging Center, McLean Hospital, Department of Psychiatry, Harvard Medical
School, 115 Mill St, Belmont MA, 02478, Phone: (617) 855-3945,
; Dost
Öngür, M.D. Ph.D., Psychotic Disorders Division, McLean
Hospital, Department of Psychiatry, Harvard Medical School, 115 Mill St, Belmont
MA, 02478, Phone:(617) 855-3922,
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Valkovič L, Ukropcová B, Chmelík M, Baláž M, Bogner W, Schmid AI, Frollo I, Zemková E, Klimeš I, Ukropec J, Trattnig S, Krššák M. Interrelation of 31P-MRS metabolism measurements in resting and exercised quadriceps muscle of overweight-to-obese sedentary individuals. NMR IN BIOMEDICINE 2013; 26:1714-1722. [PMID: 23949699 DOI: 10.1002/nbm.3008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Revised: 05/24/2013] [Accepted: 07/06/2013] [Indexed: 06/02/2023]
Abstract
Phosphorus magnetic resonance spectroscopy ((31)P-MRS) enables the non-invasive evaluation of muscle metabolism. Resting Pi-to-ATP flux can be assessed through magnetization transfer (MT) techniques, and maximal oxidative flux (Q(max)) can be calculated by monitoring of phosphocreatine (PCr) recovery after exercise. In this study, the muscle metabolism parameters of 13 overweight-to-obese sedentary individuals were measured with both MT and dynamic PCr recovery measurements, and the interrelation between these measurements was investigated. In the dynamic experiments, knee extensions were performed at a workload of 30% of maximal voluntary capacity, and the consecutive PCr recovery was measured in a quadriceps muscle with a time resolution of 2 s with non-localized (31)P-MRS at 3 T. Resting skeletal muscle metabolism was assessed through MT measurements of the same muscle group at 7 T. Significant linear correlations between the Q(max) and the MT parameters k(ATP) (r = 0.77, P = 0.002) and F(ATP) (r = 0.62, P = 0.023) were found in the study population. This would imply that the MT technique can possibly be used as an alternative method to assess muscle metabolism when necessary (e.g. in individuals after stroke or in uncooperative patients).
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Affiliation(s)
- Ladislav Valkovič
- MR Centre of Excellence, Department of Radiology, Medical University of Vienna, Vienna, Austria; Department of Imaging Methods, Institute of Measurement Science, Slovak Academy of Sciences, Bratislava, Slovak Republic
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Clinical assessment of phosphorus status, balance and renal handling in normal individuals and in patients with chronic kidney disease. Curr Opin Nephrol Hypertens 2013; 22:452-8. [DOI: 10.1097/mnh.0b013e328362483a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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