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    Changes in Serum Metabolome Following Low-Energy Diet-Induced Weight Loss in Women with Overweight and Prediabetes: A PREVIEW-New Zealand Sub-Study
    (MDPI (Basel, Switzerland), 2024-08-01) Relva B; Samuelsson LM; Duarte IF; Fasol U; Edwards PJB; Fogelholm M; Raben A; Poppitt SD; Silvestre MP; Rogero MM
    As obesity develops, metabolic changes increase the risk of non-communicable diseases such as type 2 diabetes (T2D). Weight loss is crucial for improving health in T2D and cardiometabolic conditions. However, weight loss rates vary between individuals, even with identical diets or energy restrictions, highlighting the need to identify markers or predictors of weight loss success to enhance intervention outcomes. Using nuclear magnetic resonance (NMR) spectroscopy-based metabolomics, we investigated the change in serum polar metabolites in 28 women with overweight or obesity and prediabetes who completed an 8-week low-energy diet (LED) as part of the PREVIEW (PREVention of diabetes through lifestyle intervention and population studies in Europe and around the World) clinical trial. We aimed to characterize the metabolic shift in substrate oxidation under fixed energy intake (~4 MJ/day) and its relation to weight loss success. Nine of the thirty-four serum metabolites identified significantly changed during the LED phase: 3-hydroxybutyrate, O-acetylcarnitine, 2-hydroxybutyrate, mannose, dimethyl sulfone and isobutyrate increased, whilst choline, creatine and tyrosine decreased. These results confirmed a shift towards lipid oxidation, but no metabolites predicted the response to the LED-induced weight loss. Further studies in larger populations are required to validate these metabolites as biomarkers of diet exposure.
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    Microscopic NMR imaging : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Physics at Massey University
    (Massey University, 1987) Eccles, Craig David
    In the process of developing the imaging system it was necessary to write an extensive range of software. Our only access to the TI-980A was via a series of bit switches and so the first task was to write a hex monitor which would speed program entry. A fairly extensive software package was provided with the system for the purpose of performing NMR spectroscopy and so rather than rewrite FFTs etc from scratch much of this software (conveniently in the form of subroutines) was used by the imaging system. The Hitachi was supplied without any software apart from BASIC and MSDOS. IBM PC Fortran, Pascal and assembler were obtained which ran on this machine but because of graphics and I/O incompatibilities no graphics library was available. It was therefore necessary to write a number of 8088 assembly language routines to perform these essential functions. All those routines (such as image display, backprojections and FFTs) which required rapid execution were written in assembler and called as subroutines from Fortran (this programmers language of choice). Those routines for which speed is not a primary requirement or which are currently in the development stage have been written in Hitachi Basic. This volume is divided into 2 sections. The first part contains the TI-980A routines which are used to control the imaging experiment. The second contains listings and flowcharts for programs written on the Hitachi in Fortran, Basic and assembler.
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    The Structural and Functional Characterization of Mammalian ADP-dependent Glucokinase.
    (19/02/2016) Richter JP; Goroncy AK; Ronimus RS; Sutherland-Smith AJ
    The enzyme-catalyzed phosphorylation of glucose to glucose-6-phosphate is a reaction central to the metabolism of all life. ADP-dependent glucokinase (ADPGK) catalyzes glucose-6-phosphate production, utilizing ADP as a phosphoryl donor in contrast to the more well characterized ATP-requiring hexokinases. ADPGK is found in Archaea and metazoa; in Archaea, ADPGK participates in a glycolytic role, but a function in most eukaryotic cell types remains unknown. We have determined structures of the eukaryotic ADPGK revealing a ribokinase-like tertiary fold similar to archaeal orthologues but with significant differences in some secondary structural elements. Both the unliganded and the AMP-bound ADPGK structures are in the "open" conformation. The structures reveal the presence of a disulfide bond between conserved cysteines that is positioned at the nucleotide-binding loop of eukaryotic ADPGK. The AMP-bound ADPGK structure defines the nucleotide-binding site with one of the disulfide bond cysteines coordinating the AMP with its main chain atoms, a nucleotide-binding motif that appears unique to eukaryotic ADPGKs. Key amino acids at the active site are structurally conserved between mammalian and archaeal ADPGK, and site-directed mutagenesis has confirmed residues essential for enzymatic activity. ADPGK is substrate inhibited by high glucose concentration and shows high specificity for glucose, with no activity for other sugars, as determined by NMR spectroscopy, including 2-deoxyglucose, the glucose analogue used for tumor detection by positron emission tomography.