Product-Operator Algebra for Strongly Coupled Spin Systems

Graveron‐Demilly, D.; Diop, Amadou; Briguet, A.; Fenêt, Bernard

doi:10.1006/jmra.1993.1038

Cited by 63 publications

(57 citation statements)

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“…The QUEST (Quantum estimation) method combined with subtraction approach for background modeling was used for measuring metabolite areas. Metabolite model signals of Cho (cholinecontaining compounds, Cr (total creatine), glutamate/ glutamine, NAA, and lactate were quantum mechanically simulated in nuclear magnetic resonance spectra calculation using operators (nuclear magnetic resonance-SCOPE) (Graverondemilly et al, 1993). The numerical time-domain model functions of these metabolites were then used as previous knowledge in QUEST.…”

Section: Data Processingmentioning

confidence: 99%

Association between pH-Weighted Endogenous Amide Proton Chemical Exchange Saturation Transfer MRI and Tissue Lactic Acidosis during Acute Ischemic Stroke

Sun

Cheung

Wang

et al. 2011

J Cereb Blood Flow Metab

127

139

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The ischemic tissue becomes acidic after initiation of anaerobic respiration, which may result in impaired tissue metabolism and, ultimately, in severe tissue damage. Although changes in the major cerebral metabolites can be studied using magnetic resonance (MR) spectroscopy (MRS)-based techniques, their spatiotemporal resolution is often not sufficient for routine examination of fastevolving and heterogeneous acute stroke lesions. Recently, pH-weighted MR imaging (MRI) has been proposed as a means to assess tissue acidosis by probing the pH-dependent chemical exchange of amide protons from endogenous proteins and peptides. In this study, we characterized acute ischemic tissue damage using localized proton MRS and multiparametric imaging techniques that included perfusion, diffusion, pH, and relaxation MRI. Our study showed that pH-weighted MRI can detect ischemic lesions and strongly correlates with tissue lactate content measured by 1 H MRS, indicating lactic acidosis. Our results also confirmed the correlation between apparent diffusion coefficient and lactate; however, no significant relationship was found for perfusion, T 1 , and T 2 . In summary, our study showed that optimized endogenous pH-weighted MRI, by sensitizing to local tissue pH, remains a promising tool for providing a surrogate imaging marker of lactic acidosis and altered tissue metabolism, and augments conventional techniques for stroke diagnosis.

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Section: Data Processingmentioning

confidence: 99%

Association between pH-Weighted Endogenous Amide Proton Chemical Exchange Saturation Transfer MRI and Tissue Lactic Acidosis during Acute Ischemic Stroke

Sun

Cheung

Wang

et al. 2011

J Cereb Blood Flow Metab

127

139

View full text Add to dashboard Cite

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“…Although oxaliplatin-induced neuropathic pain results from peripheral nerve neurotoxicity, we suspect that brain centers may be involved in the development and/or the maintenance of chronic pain as for other neuropathic pain conditions. Indeed, many chronic painful states have been associated with activation/ deactivation and/or gray matter losses in various brain areas involved in pain processing, including the somatosensory cortices, insula, amygdala, cingulate gyrus, and thalamus (Apkarian et al, 2004;Kuchinad et al, 2007;DaSilva et al, 2008;Burgmer et al, 2009;Gustin et al, 2010). Therefore, changes in some of these brain areas might also participate in oxaliplatin-induced neuropathic pain.…”

Section: Significance Statementmentioning

confidence: 99%

“…This procedure uses a metabolite database set simulated by quantum mechanics with NMR-SCOPE (NMR Spectra Calculation using OPErators) (GraveronDemilly et al, 1993) using spin parameters from Govindaraju et al (2000). Seventeen metabolites were quantified: acetate (Ace), alanine (Ala), aspartate (Asp), creatine and phosphocreatine (Cr), choline (Cho), GABA, glutamate (Glu), glutamine (Gln), glutathione (GSH), glycerophosphocholine (GPC), glycine (Gly), lactate (Lac), myo-inositol (m-Ins), N-acetyl-aspartate (NAA), phosphocholine (PC), taurine (Tau), and scyllo-inositol (s-Ins).…”

Section: Metabolite Quantificationmentioning

confidence: 99%

“…Among neuropathic pain conditions, oxaliplatin, an anticancer drug widely used for the adjuvant treatment of advanced colorectal cancer (André et al, 2004), is responsible for incapacitating and dose-limiting neurotoxicity with two components: acute nerve hyperexcitability and chronic cumulative peripheral neuropathy. Oxaliplatin is responsible for acute sensory symptoms, including cold allodynia in Ͼ90% of patients (Raymond et …”

Section: Introductionmentioning

confidence: 99%

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Cholinergic Neurotransmission in the Posterior Insular Cortex Is Altered in Preclinical Models of Neuropathic Pain: Key Role of Muscarinic M2 Receptors in Donepezil-Induced Antinociception

et al. 2015

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Neuropathic pain is one of the most debilitating pain conditions, yet no therapeutic strategy has been really effective for its treatment. Hence, a better understanding of its pathophysiological mechanisms is necessary to identify new pharmacological targets. Here, we report important metabolic variations in brain areas involved in pain processing in a rat model of oxaliplatin-induced neuropathy using HRMAS 1 H-NMR spectroscopy. An increased concentration of choline has been evidenced in the posterior insular cortex (pIC) of neuropathic animal, which was significantly correlated with animals' pain thresholds. The screening of 34 genes mRNA involved in the pIC cholinergic system showed an increased expression of the high-affinity choline transporter and especially the muscarinic M2 receptors, which was confirmed by Western blot analysis in oxaliplatin-treated rats and the spared nerve injury model (SNI). Furthermore, pharmacological activation of M2 receptors in the pIC using oxotremorine completely reversed oxaliplatin-induced mechanical allodynia. Consistently, systemic treatment with donepezil, a centrally active acetylcholinesterase inhibitor, prevented and reversed oxaliplatin-induced cold and mechanical allodynia as well as social interaction impairment. Intracerebral microdialysis revealed a lower level of acetylcholine in the pIC of oxaliplatin-treated rats, which was significantly increased by donepezil. Finally, the analgesic effect of donepezil was markedly reduced by a microinjection of the M2 antagonist, methoctramine, within the pIC, in both oxaliplatin-treated rats and spared nerve injury rats. These findings highlight the crucial role of cortical cholinergic neurotransmission as a critical mechanism of neuropathic pain, and suggest that targeting insular M2 receptors using central cholinomimetics could be used for neuropathic pain treatment.

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“…Introduced in 1994 [36], the GAMMA C++ library is a flexible and efficient tool for describing and simulating MR experiments. Since the early 1990s, there have been reports of a number of other NMR simulation libraries [5,16,22] and application tools [1,2,15,17,27,29,32,49] which have sought to provide similar functionality in either a more optimized or user friendly fashion. The growth in available tools reflects the consensus among MR scientists that simulation methods are a necessary and desirable step in the development of increasingly sophisticated data acquisition/analysis methods for viewing complex molecular systems.…”

Section: Introductionmentioning

confidence: 99%

GAVA: Spectral simulation for in vivo MRS applications

Soher

Young

Bernstein

et al. 2007

Journal of Magnetic Resonance

109

102

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An application that provides a flexible and easy to use interface to the GAMMA spectral simulation package is described that is targeted at investigations using in vivo MR spectroscopic methods. The program makes available a number of widely used spatially-localized MRS pulse sequences and NMR parameters for commonly-observed tissue metabolites, enabling spectra to be simulated for any pulse sequence parameter and viewed in an integrated display. The application is interfaced with a database for storage of all simulation parameters and results of the simulations. This application provides a convenient method for generating a priori spectral information used in parametric spectral analyses and for visual examination of the effects of difference pulse sequences and parameter settings.

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Product-Operator Algebra for Strongly Coupled Spin Systems

Cited by 63 publications

References 0 publications

Association between pH-Weighted Endogenous Amide Proton Chemical Exchange Saturation Transfer MRI and Tissue Lactic Acidosis during Acute Ischemic Stroke

Association between pH-Weighted Endogenous Amide Proton Chemical Exchange Saturation Transfer MRI and Tissue Lactic Acidosis during Acute Ischemic Stroke

Cholinergic Neurotransmission in the Posterior Insular Cortex Is Altered in Preclinical Models of Neuropathic Pain: Key Role of Muscarinic M2 Receptors in Donepezil-Induced Antinociception

GAVA: Spectral simulation for in vivo MRS applications

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