Plasma Nuclear Magnetic Resonance Metabolomics Discriminates Between High and Low Endoscopic Activity and Predicts Progression in a Prospective Cohort of Patients With Ulcerative Colitis

Abstract

Plasma NMR metabolite analysis has the potential to provide a low-cost, minimally invasive technique that may be a surrogate for endoscopic assessment, with predictive capacity.

Post-inflammatory behavioural despair in male mice is associated with reduced cortical glutamate-glutamine ratios, and circulating lipid and energy metabolites

“…1 H NMR spectra were acquired using a 700-MHz Bruker AVII spectrometer operating at 16.4 T equipped with a 1 H (13C/15 N) TCI cryoprobe 52 . Sample temperature was stable at 310 K. 1 H NMR spectra were acquired using a one-dimensional (1D) Nuclear Overhauser Effect Spectroscopy (NOESY) pre-saturation scheme for attenuation of the water resonance with a 2 s pre-saturation 52 .…”

“…1 H NMR spectra were acquired using a 700-MHz Bruker AVII spectrometer operating at 16.4 T equipped with a 1 H (13C/15 N) TCI cryoprobe 52 . Sample temperature was stable at 310 K. 1 H NMR spectra were acquired using a one-dimensional (1D) Nuclear Overhauser Effect Spectroscopy (NOESY) pre-saturation scheme for attenuation of the water resonance with a 2 s pre-saturation 52 . An additional sequence, the spin-echo Carr-Purcell-Meiboom-Gill (CPMG) sequence, was used for plasma samples to suppress broad signals arising from large molecular weight plasma components with a τ interval of 400 μs, 80 loops, 32 data collections, an acquisition time of 1.5 s, a relaxation delay of 2 s, and a fixed receiver gain 51 .…”

“…Processing methods were adapted from previously published methods and parameters 51 , 52 . NMR spectra were imported into MestreNova (Mestrelab Research, Spain) and each spectrum was then processed manually with phase 0 (PH0) correction, baseline correction (Bernstein polynomial fit, order = 3), and referencing to an added standard (TSP referenced to δ0) for brain tissue, and an internal standard (Lactate referenced to δ1.33) for plasma.…”

“…1 H Nuclear Magnetic Resonance (NMR) Spectroscopy. Sample preparation was performed as previously described [51][52][53] . Briefly, plasma samples were defrosted on ice and centrifuged at 17,000 xg for 5 min at 4 °C.…”

“…Briefly, plasma samples were defrosted on ice and centrifuged at 17,000 xg for 5 min at 4 °C. An equal volume of plasma was aliquoted (100 μL) into a fresh tube and diluted to 600 μL in a 75 mM phosphate buffer ( 1 H NMR spectra were acquired using a 700-MHz Bruker AVII spectrometer operating at 16.4 T equipped with a 1 H (13C/15 N) TCI cryoprobe 52 . Sample temperature was stable at 310 K. 1 H NMR spectra were acquired using a one-dimensional (1D) Nuclear Overhauser Effect Spectroscopy (NOESY) pre-saturation scheme for attenuation of the water resonance with a 2 s pre-saturation 52 .…”