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Functional imaging and emerging techniques in MRI
Published in Anju Sahdev, Sarah J. Vinnicombe, Husband & Reznek's Imaging in Oncology, 2020
Roberto García-Figueiras, Anwar Padhani, Sandra Baleato-González
31P-MRS has also been used to monitor tumour energetics (predominantly based on ATP) and cell membrane turnover (phospholipid metabolites) (72) (Figure 42.14). Additionally, tumour pH can be calculated using different MRI techniques, although these measurements are still limited in spatial and temporal resolution. MRS measurements are based on the chemical-shift differences between pH-dependent and independent resonances in 31P-MRS (98). Human cancers are characterized by elevated phosphomonoesters and phosphodiesters, and an acidic extracellular pH (81,82,98).
CT, MRI, and NMR Spectroscopy in Alzheimer Disease*
Published in Robert E. Becker, Ezio Giacobini, Alzheimer Disease, 2020
Liane J. Leedom, Bruce L. Miller
Pettegrew reported extensive changes in phosphomono and phosphodiesters of choline and ethanolamine in the brains of patients with AD with in vivo NMR spectroscopy (Pettegrew In Press). Specifically, he found that in addition to glycerophosphorylcholine and glycerophosphorylethanolamine that, phosphorylcholine and phosphorylethanolamine were elevated in AD brains. Pettegrew notes that the phosphomonoesters are anabolic building blocks necessary for the production of brain phospholipids and their accumulation could mean a metabolic block. Conversely, it might mean that there was an excessive degradation of the diesters by phospholipase C although this has not been demonstrated in chemical studies (Kanfer et al., 1987).
Future Developments of Multinuclear NMR Spectroscopy (MRS) in Clinical Examinations
Published in Bertil R. R. Persson, Freddy Ståhlberg, Health and Safety of Clinical NMR Examinations, 2019
Bertil R. R. Persson, Freddy Ståhlberg
31P-NMR spectra can provide information regarding the composition and level of phosphate metabolites and can thus be used to characterize the cellular energetic status. Figure 1 shows the 31P-NMR spectrum of a malignant tumor (infiltrating duct carcinoma). The 31P-NMR spectra of both benign and malignant tumors show the presence of signals due to the following phosphorus compounds: Pi = inorganic phosphatesPCr = phosphocreatinineATP = adenosine-5′-triphosphateADP = adenosine-5′ -diphosphateUDPG = uridinenucleoside diphosphoglucosePDE = phosphodiestersPME = phosphomonoesters
Novel plasma metabolite markers of attention-deficit/hyperactivity disorder identified using high-performance chemical isotope labelling-based liquid chromatography-mass spectrometry
Published in The World Journal of Biological Psychiatry, 2021
Liang-Jen Wang, Wen-Jiun Chou, Ching-Shu Tsai, Min-Jing Lee, Sheng-Yu Lee, Chia-Wei Hsu, Pei-Chun Hsueh, Chih-Ching Wu
Phosphoethanolamine (PE), a phosphomonoester metabolite of the phospholipid metabolism, is a precursor of phospholipid synthesis and a product of phospholipid breakdown. In the developing brain, PE is generally elevated during the period of neuritic proliferation. PE shows a strong structural similarity to the inhibitory neurotransmitter, such as GABA and 3-amino-propylphosphonic acid (Bostwick et al. 1989). A metabolomic analysis in an animal model indicated that O-phosphoethanolamine may be a potential biomarker that influences cholesterol metabolism and may be implicated in the development of ADHD-like behaviour (Chen et al. 2019). This finding is consistent with our study, in which O-phosphoethanolamine was overexpressed in our ADHD sample.
Biomarkers of liver fibrosis: prospective comparison of multimodal magnetic resonance, serum algorithms and transient elastography
Published in Scandinavian Journal of Gastroenterology, 2020
Mikael F. Forsgren, Patrik Nasr, Markus Karlsson, Nils Dahlström, Bengt Norén, Simone Ignatova, Ralph Sinkus, Gunnar Cedersund, Olof Dahlqvist Leinhard, Mattias Ekstedt, Stergios Kechagias, Peter Lundberg
The 31P-MRS was performed using a flat, non-flexible 12 cm circular single tuned surface coil (‘P-120’, Philips Healthcare, Ville Platte, LA). The localised hepatic spectra were acquired using ISIS volume selection (7 s repetition time; 1024 data points; 5 kHz spectral width; 192 averages; volume 60 × 60 × 40 mm3). The MRS data were post-processed and analysed for phosphomonoesters (PME), phosphodiester (PDE), and the anabolic charge (AC) was calculated (AC = PME/(PME + PDE incl. MP)) as previously described [27,37], using jMRUI with the AMARES algorithm [38,39]. The spectral analysis was performed by an experienced MR physicist (MFF). The spectral assignments are exemplified in Figure 2(E,F).
Tricyclic coumarin sulphonate derivatives with alkaline phosphatase inhibitory effects: in vitro and docking studies
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2018
Jamshed Iqbal, Mohammed I. El-Gamal, Syeda Abida Ejaz, Joanna Lecka, Jean Sévigny, Chang-Hyun Oh
Alkaline phosphatases (APs, E.C. 3.1.3.1) are membrane-bound ecto-enzymes with an extracellular-oriented active site1. They belong to the large family of ecto-enzyme known as ecto-nucleotidases, and are involved in various physiological functions within the human body, most importantly in phosphorylation and dephosphorylation reactions2. They are also responsible for the hydrolysis and breakdown of wide variety of nucleoside tri- and di-phosphates substrates to their respective monophosphates3,4. They also hydrolyse many other phosphate-containing substrates, such as inorganic pyrophosphate (PPi), glucose phosphate, polyphosphates, phosphomonoesters, and phosphatidates5. APs are further categorised into two types, the tissue-specific and tissue-nonspecific alkaline phosphatases (TNAPs). From the tissue-specific AP type, intestinal alkaline phosphatase (IAP) plays a pivotal role in the maintenance of physiological environment of the intestine6. Moreover, this isozyme is important for the regulation of bicarbonate secretion balance, duodenal luminal pH, dephosphorylation reaction, and helps in the maintenance of normal gut environment by detoxifying the bacterial toxins7. TNAP is widely distributed almost in each body part but is abundantly present in central nervous tissues, mineralising tissues and also in kidney8. As compared to the other body tissues, high concentration of TNAP is present in the mineralising tissues such as teeth and bones for the normal teeth and bone formation. But too high concentrations of TNAP in mineralising tissue results in abnormal calcification and mineral deposition9. The identification of effective inhibitors of AP isozymes becomes an emerging drug target for the disorders related to the hyper-activity of TNAP and IAP. To date, different inhibitors of APs based on triazole, pyrazoles, coumarin sulphonates, diaryl sulphonamides, and chromones have been identified as effective inhibitors of TNAP and IAP (Figure 1)10–13.