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Deuterium metabolic imaging - Back to the future.
De Feyter, HM, de Graaf, RA
Journal of magnetic resonance (San Diego, Calif. : 1997). 2021;:106932
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Abstract
Deuterium metabolic spectroscopy (DMS) and imaging (DMI) have recently been described as simple and robust MR-based methods to map metabolism with high temporal and/or spatial resolution. The metabolic fate of a wide range of suitable deuterated substrates, including glucose and acetate, can be monitored with deuterium MR methods in which the favorable MR characteristics of deuterium prevent many of the complications that hamper other techniques. The short T1 relaxation times lead to good MR sensitivity, while the low natural abundance prevents the need for water or lipid suppression. The sparsity of the deuterium spectra in combination with the low resonance frequency provides relative immunity to magnetic field inhomogeneity. Taken together, these features combine into a highly robust metabolic imaging method that has strong potential to become a dominant MR research tool and a viable clinical imaging modality. This perspective reviews the history of deuterium as a metabolic tracer, the use of NMR as a detection method for deuterium in vitro and in vivo and the recent development of DMS and DMI. Following a review of the NMR characteristics and the biological effects of deuterium, the promising future of DMI is outlined.
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Myocardial inflammation and energetics by cardiac MRI: a review of emerging techniques.
Tsampasian, V, Swift, AJ, Assadi, H, Chowdhary, A, Swoboda, P, Sammut, E, Dastidar, A, Cabrero, JB, Del Val, JR, Nair, S, et al
BMC medical imaging. 2021;(1):164
Abstract
The role of inflammation in cardiovascular pathophysiology has gained a lot of research interest in recent years. Cardiovascular Magnetic Resonance has been a powerful tool in the non-invasive assessment of inflammation in several conditions. More recently, Ultrasmall superparamagnetic particles of iron oxide have been successfully used to evaluate macrophage activity and subsequently inflammation on a cellular level. Current evidence from research studies provides encouraging data and confirms that this evolving method can potentially have a huge impact on clinical practice as it can be used in the diagnosis and management of very common conditions such as coronary artery disease, ischaemic and non-ischaemic cardiomyopathy, myocarditis and atherosclerosis. Another important emerging concept is that of myocardial energetics. With the use of phosphorus magnetic resonance spectroscopy, myocardial energetic compromise has been proved to be an important feature in the pathophysiological process of several conditions including diabetic cardiomyopathy, inherited cardiomyopathies, valvular heart disease and cardiac transplant rejection. This unique tool is therefore being utilized to assess metabolic alterations in a wide range of cardiovascular diseases. This review systematically examines these state-of-the-art methods in detail and provides an insight into the mechanisms of action and the clinical implications of their use.
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NMR spectroscopy: a powerful tool for the analysis of polyphenols in extra virgin olive oil.
Olmo-Cunillera, A, López-Yerena, A, Lozano-Castellón, J, Tresserra-Rimbau, A, Vallverdú-Queralt, A, Pérez, M
Journal of the science of food and agriculture. 2020;(5):1842-1851
Abstract
Extra virgin olive oil (EVOO), a key component of the Mediterranean diet, has aroused interest in recent years due to its health properties. Nuclear magnetic resonance (NMR) spectroscopy is an appropriate tool for the accurate quantification of minor compounds in complex food matrices, such as polyphenols in olive oil. Flavonoids, lignans, secoiridoids and phenolic acids and alcohols in EVOO have been identified and quantified by NMR. This review provides an overview of the major developments in the structural elucidation of polyphenol compounds in EVOO. © 2019 Society of Chemical Industry.
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MR imaging and spectroscopy in degenerative ataxias: toward multimodal, multisite, multistage monitoring of neurodegeneration.
Öz, G, Harding, IH, Krahe, J, Reetz, K
Current opinion in neurology. 2020;(4):451-461
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Abstract
PURPOSE OF REVIEW Degenerative ataxias are rare and currently untreatable movement disorders, primarily characterized by neurodegeneration in the cerebellum and brainstem. We highlight MRI studies with the most potential for utility in pending ataxia trials and underscore advances in disease characterization and diagnostics in the field. RECENT FINDINGS With availability of advanced MRI acquisition methods and specialized software dedicated to the analysis of MRI of the cerebellum, patterns of cerebellar atrophy in different degenerative ataxias are increasingly well defined. The field further embraced rigorous multimodal investigations to study network-level microstructural and functional brain changes and their neurochemical correlates. MRI and magnetic resonance spectroscopy were shown to be more sensitive to disease progression than clinical scales and to detect abnormalities in premanifest mutation carriers. SUMMARY Magnetic resonance techniques are increasingly well placed for characterizing the expression and progression of degenerative ataxias. The most impactful work has arguably come through multi-institutional studies that monitor relatively large cohorts, multimodal investigations that assess the sensitivity of different measures and their interrelationships, and novel imaging approaches that are targeted to known pathophysiology (e.g., iron and spinal imaging in Friedreich ataxia). These multimodal, multi-institutional studies are paving the way to clinical trial readiness and enhanced understanding of disease in degenerative ataxias.
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Recent directions in the solid-state NMR study of synthetic and natural calcium phosphates.
Gervais, C, Bonhomme, C, Laurencin, D
Solid state nuclear magnetic resonance. 2020;:101663
Abstract
Materials containing a calcium phosphate component have been the subject of much interest to NMR spectroscopists, especially in view of understanding the structure and properties of mineralized tissues like bone and teeth, and of developing synthetic biomaterials for bone regeneration. Here, we present a selection of recent developments in their structural characterization using advanced solid state NMR experiments, highlighting the level of insight which can now be accessed.
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Characterization of Carbonic Anhydrase In Vivo Using Magnetic Resonance Spectroscopy.
Tomar, JS, Shen, J
International journal of molecular sciences. 2020;(7)
Abstract
Carbonic anhydrase is a ubiquitous metalloenzyme that catalyzes the reversible interconversion of CO2/HCO3-. Equilibrium of these species is maintained by the action of carbonic anhydrase. Recent advances in magnetic resonance spectroscopy have allowed, for the first time, in vivo characterization of carbonic anhydrase in the human brain. In this article, we review the theories and techniques of in vivo 13C magnetization (saturation) transfer magnetic resonance spectroscopy as they are applied to measuring the rate of exchange between CO2 and HCO3- catalyzed by carbonic anhydrase. Inhibitors of carbonic anhydrase have a wide range of therapeutic applications. Role of carbonic anhydrases and their inhibitors in many diseases are also reviewed to illustrate future applications of in vivo carbonic anhydrase assessment by magnetic resonance spectroscopy.
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NMR Metabolomics Applied on the Discrimination of Variables Influencing Tomato (Solanum lycopersicum).
Abreu, AC, Fernández, I
Molecules (Basel, Switzerland). 2020;(16)
Abstract
Tomato composition and nutritional value are attracting increasing attention and interest from both consumers and producers. The interest in enhancing fruits' quality with respect to beneficious nutrients and flavor/aroma components is based not only in their economic added value but also in their implications involving organoleptic and healthy properties and has generated considerable research interest among nutraceutical and horticultural industries. The present article reviews up to March 2020 some of the most relevant studies based on the application of NMR coupled to multivariate statistical analysis that have addressed the investigation on tomato (Solanum lycopersicum). Specifically, the NMR untargeted technique in the agri-food sector can generate comprehensive data on metabolic networks and is paving the way towards the understanding of variables affecting tomato crops and composition such as origin, variety, salt-water irrigation, cultivation techniques, stage of development, among many others. Such knowledge is helpful to improve fruit quality through cultural practices that divert the metabolism towards the desired pathways and, probably more importantly, drives further efforts towards the differentiation of those crops developed under controlled and desired agronomical conditions.
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Magnetic Resonance Spectroscopy of the Head and Neck: Principles, Applications, and Challenges.
Fujima, N, Carlota Andreu-Arasa, V, Barest, GD, Srinivasan, A, Sakai, O
Neuroimaging clinics of North America. 2020;(3):283-293
Abstract
Several investigations have revealed the utility of magnetic resonance spectroscopy (MRS) as an adjunct in the evaluation of lesions of the head and neck. This technique remains a challenge in the head and neck because of its low signal-to-noise ratio and long acquisition times. In this review article, the basics of image acquisition technique and reported clinical utilities of head and neck MRS are presented.
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The potentiality of NMR-based metabolomics in food science and food authentication assessment.
Consonni, R, Cagliani, LR
Magnetic resonance in chemistry : MRC. 2019;(9):558-578
Abstract
In the last years, there was an increasing interest on nuclear magnetic resonance (NMR) spectroscopy, whose applications experienced an exponential growth in several research fields, particularly in food science. NMR was initially developed as the elective technique for structure elucidation of single molecules and nowadays is playing a dominant role in complex mixtures investigations. In the era of the "omics" techniques, NMR was rapidly enrolled as one of the most powerful methods to approach metabolomics studies. Its use in analytical routines, characterized by rapid and reproducible measurements, would provide the identification of a wide range of chemical compounds simultaneously, disclosing sophisticated frauds or addressing the geographical origin, as well as revealing potential markers for other authentication purposes. The great economic value of high-quality or guaranteed foods demands highly detailed characterization to protect both consumers and producers from frauds. The present scenario suggests metabolomics as the privileged approach of modern analytical studies for the next decades. The large potentiality of high-resolution NMR techniques is here presented through specific applications and using different approaches focused on the authentication process of some foods, like tomato paste, saffron, honey, roasted coffee, and balsamic and traditional balsamic vinegar of Modena, with a particular focus on geographical origin characterization, ageing determination, and fraud detection.
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Understanding Protein Function Through an Ensemble Description: Characterization of Functional States by 19F NMR.
Di Pietrantonio, C, Pandey, A, Gould, J, Hasabnis, A, Prosser, RS
Methods in enzymology. 2019;:103-130
Abstract
Protein function is a consequence of a complex and dynamic equilibrium between allosterically coupled functional states. However, it is often difficult to distinguish the representative members of an ensemble by spectroscopic means. 19F NMR is particularly useful in this regard owing to the sensitivity of its chemical shift to subtle differences in environment. Here, we address aspects of 19F NMR relevant to the study of ensembles. In particular, we discuss current trends toward: (1) 19F-reporters that can be biosynthetically incorporated into proteins, (2) Approaches to chemical tagging of proteins by 19F reporters, (3) Improving delineation of states by 19F NMR, (4) Distinguishing states by (19F NMR-based) topology measurements that focus on solvent exposure and hydrophobicity, (5) Relaxation experiments and simple approaches to delineating states in fast and slow exchange, (6) Extending resolution of states by 19F NMR, and (7) Validating 19F NMR spectroscopy by computational methods. Many of these advances are demonstrated through recent 19F NMR studies of a homodimeric enzyme, fluoroacetate dehalogenase.