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108 results on '"Griffiths, W.J."'

4. Adult liver transplantation: what non-specialists need to know

Author

Hirschfield, G.M., Gibbs, P., and Griffiths, W.J,H.

Subjects
Physicians (General practice) -- Practice, Donation of organs, tissues, etc. -- Laws, regulations and rules, Medical personnel -- Practice, Liver -- Transplantation, Liver -- Laws, regulations and rules, Government regulation
Published
2009

5. Gene expression identifies metabolic and functional differences between intramuscular and subcutaneous adipocytes in cattle

Author

Hudson, N.J., Reverter, A., Griffiths, W.J., Yutuc, E., Wang, Y., Jeanes, A., McWilliam, S., Pethick, D.W., Greenwood, P.L., Hudson, N.J., Reverter, A., Griffiths, W.J., Yutuc, E., Wang, Y., Jeanes, A., McWilliam, S., Pethick, D.W., and Greenwood, P.L.

Abstract

Background This study used a genome-wide screen of gene expression to better understand the metabolic and functional differences between commercially valuable intramuscular fat (IMF) and commercially wasteful subcutaneous (SC) fat depots in Bos taurus beef cattle. Results We confirmed many findings previously made at the biochemical level and made new discoveries. The fundamental lipogenic machinery, such as ACACA and FASN encoding the rate limiting Acetyl CoA carboxylase and Fatty Acid synthase were expressed at 1.6–1.8 fold lower levels in IMF, consistent with previous findings. The FA elongation pathway including the rate limiting ELOVL6 was also coordinately downregulated in IMF compared to SC as expected. A 2-fold lower expression in IMF of ACSS2 encoding Acetyl Coenzyme A synthetase is consistent with utilisation of less acetate for lipogenesis in IMF compared to SC as previously determined using radioisotope incorporation. Reduced saturation of fat in the SC depot is reflected by 2.4 fold higher expression of the SCD gene encoding the Δ9 desaturase enzyme. Surprisingly, CH25H encoding the cholesterol 25 hydroxylase enzyme was ~ 36 fold upregulated in IMF compared to SC. Moreover, its expression in whole muscle tissue appears representative of the proportional representation of bovine marbling adipocytes. This suite of observations prompted quantification of a set of oxysterols (oxidised forms of cholesterol) in the plasma of 8 cattle exhibiting varying IMF. Using Liquid Chromatography-Mass Spectrometry (LC-MS) we found the levels of several oxysterols were significantly associated with multiple marbling measurements across the musculature, but (with just one exception) no other carcass phenotypes. Conclusions These data build on our molecular understanding of ruminant fat depot biology and suggest oxysterols represent a promising circulating biomarker for cattle marbling.

Published
2020

7. First international descriptive and interventional survey for cholesterol and non-cholesterol sterol determination by gas- and liquid- chromatography–Urgent need for harmonisation of analytical methods

Author

Lütjohann, D. (Dieter), Björkhem, I. (Ingemar), Friedrichs, S. (Silvia), Kerksiek, A. (Anja), Lövgren-Sandblom, A. (Anita), Geilenkeuser, W.J. (Wolf Jochen), Ahrends, R. (Robert), Andrade, I. (Isabel), Ansorena-Artieda, D. (Diana), Astiasarán, I. (Iciar), Baila-Rueda, L. (Lucía), Barriuso, B. (Blanca), Becker, S. (Susen), Bretillon, L. (Lionel), Browne, R.W. (Richard W.), Caccia, C. (Claudio), Ceglarek, U. (Uta), Cenarro, A. (Ana), Crick, P.J. (Peter J.), Fauler, G. (Günter), Garcia-Llatas, G. (Guadalupe), Gray, R. (Robert), Griffiths, W.J. (William J.), Gylling, H. (Helena), Harding, S. (Scott), Helmschrodt, C. (Christin), Iuliano, L. (Luigi), Janssen, H.G. (Hans Gerd), Jones, P. (Peter), Kaipiainen, L. (Leena), Kannenberg, F. (Frank), Lagarda, M.J. (María Jesús), Leoni, V. (Valerio), Lottenberg, A.M. (Ana María), Myrie, S.B. (Semone B.), MacKay, D.S. (Dylan S.), Matysik, S. (Silke), McDonald, J. (Jeff), Menendez-Carreño, M. (María), Nunes, V.S. (Valeria Sutti), Ostlund, R.E. (Richard E.), Polisecki, E. (Eliana), Ramos, F. (Fernando), Rideout, T.C. (Todd C.), Schaefer, E.J. (Ernst J.), Schmitz, G. (Gerd), Wang, Y. (Yuqin), Zerbinati, C. (Chiara), Diczfalusy, U. (Ulf), and Schött, H.F. (Hans Frieder)

Subjects
Cholesterol balance, Cholesterol synthesis, Phytosterols, lipids (amino acids, peptides, and proteins), Cholesterol absorption, Surrogate marker, Atherosclerosis
Abstract

Serum concentrations of lathosterol, the plant sterols campesterol and sitosterol and the cholesterol metabolite 5α-cholestanol are widely used as surrogate markers of cholesterol synthesis and absorption, respectively. Increasing numbers of laboratories utilize a broad spectrum of well-established and recently developed methods for the determination of cholesterol and non-cholesterol sterols (NCS). In order to evaluate the quality of these measurements and to identify possible sources of analytical errors our group initiated the first international survey for cholesterol and NCS. The cholesterol and NCS survey was structured as a two-part survey which took place in the years 2013 and 2014. The first survey part was designed as descriptive, providing information about the variation of reported results from different laboratories. A set of two lyophilized pooled sera (A and B) was sent to twenty laboratories specialized in chromatographic lipid analysis. The different sterols were quantified either by gas chromatography-flame ionization detection, gas chromatography- or liquid chromatography-mass selective detection. The participants were requested to determine cholesterol and NCS concentrations in the provided samples as part of their normal laboratory routine. The second part was designed as interventional survey. Twenty-two laboratories agreed to participate and received again two different lyophilized pooled sera (C and D). In contrast to the first international survey, each participant received standard stock solutions with defined concentrations of cholesterol and NCS. The participants were requested to use diluted calibration solutions from the provided standard stock solutions for quantification of cholesterol and NCS. In both surveys, each laboratory used its own internal standard (5α-cholestane, epicoprostanol or deuterium labelled sterols). Main outcome of the survey was, that unacceptably high interlaboratory variations for cholesterol and NCS concentrations are reported, even when the individual laboratories used the same calibration material. We discuss different sources of errors and recommend all laboratories analysing cholesterol and NCS to participate in regular quality control programs.

Published
2019

8. A new derivative for oxosteroid analysis by mass spectrometry

Author

Rigdova, K., Wang, Y., Ward, M., and Griffiths, W.J.

Subjects
Tandem mass spectrometry, Steroid glucuronides, Biophysics, Steroids, Cell Biology, Urine, Derivatisation, Biochemistry, Molecular Biology
Abstract

Here we report a new method for oxosteroid identification utilizing “tandem mass tag hydrazine” (TMTH) carbonyl-reactive derivatisation reagent. TMTH is a reagent with a chargeable tertiary amino group attached through a linker to a carbonyl-reactive hydrazine group. Thirty oxosteroids were analysed after derivatisation with TMTH by electrospray ionization mass spectrometry (ESI-MS) and were found to give high ion-currents compared to underivatised molecules. ESI-tandem mass spectrometry (MS/MS) analysis of the derivatives yielded characteristic fragmentation patterns with specific mass reporter ions derived from the TMT group. A shotgun ESI-MS method incorporating TMTH derivatisation was applied to a urine sample.

Published
2014
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12. Microsomal glutathione transferase 1 exhibits one-third-of-the-sites-reactivity towards glutathione

Author

Ålander, J., Lengqvist, J., Holm, P.J., Svensson, R., Gerbaux, P., van der Heuvel, R.H.H., Hebert, Hans, Griffiths, W.J., Armstrong, R.N., Morgenstern, R., Ålander, J., Lengqvist, J., Holm, P.J., Svensson, R., Gerbaux, P., van der Heuvel, R.H.H., Hebert, Hans, Griffiths, W.J., Armstrong, R.N., and Morgenstern, R.

Abstract

The trimeric membrane protein microsomal glutathione transferase 1 (MGST1) possesses glutathione transferase and peroxidase activity. Previous data indicated one active site/trimer whereas structural data suggests three GSH-binding sites. Here we have determined ligand interactions of MGST1 by several techniques. Nanoelectrospray mass spectrometry of native MGST1 revealed binding of three GSH molecules/trimer and equilibrium dialysis showed three product molecules/trimer (K(d) = 320 +/- 50 mu M). All three product molecules Could be competed out with GSH. Reinvestigation of GSH-binding showed one high affinity site per trimer, consistent with earlier data. Using single turnover stopped flow kinetic measurements, Kd could be determined for a low affinity GSH-binding site (2.5 +/- 0.5 mu M). Thus we can reconcile previous observations and show here that MGST1 contains three active sites with different affinities for GSH and that only the high affinity site is catalytically competent., QC 20120214

Published
2009
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20. Doubly ionized states of carbon tetrafluoride

Author

Griffiths, W.J., primary, Svensson, S., additional, Naves de Brito, A., additional, Correia, N., additional, Reid, C.J., additional, Langford, M.L., additional, Harris, F.M., additional, Liegener, C.M., additional, and Ågren, H., additional

Published
1993
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27. Letter: Differentiation of Isomeric Mercapturic Acid Pathway Metabolites of Benzo[a]pyrene

Author

Yang, Y., Rafter, J., Gustafsson, J.-Å., Sjövall, J., and Griffiths, W.J.

Abstract

Isomeric forms of the mercapturic acid pathway metabolites of benzo[a]pyrene (BP) can be differentiated by positive-ion electrospray collision-induced dissociation (CID) mass spectrometry at the nanogram level. The metabolite (±)-r-7,t-8-dihydroxy-t-9,10-epoxy-7,8,9,10-tetrahydrobenzo[a]pyrene (BPDE), conjugated at position 10 (bay region) with cysteine, fragments to give characteristic ions at m/z303 corresponding to a BP-triol cation, these ions are not observed in the CID spectra of BPDEs conjugated at position 7 (non-bay region).

Published
1997
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