Michael Lever

Summary

Affiliation: University of Otago
Country: New Zealand

Publications

  1. doi request reprint Plasma betaine concentrations correlate with plasma cortisol but not with C-reactive protein in an elderly population
    Michael Lever
    Clinical Biochemistry Unit, Canterbury Health Laboratories, Christchurch, New Zealand
    Clin Chem Lab Med 50:1635-40. 2012
  2. pmc Betaine and secondary events in an acute coronary syndrome cohort
    Michael Lever
    Clinical Biochemistry Unit, Canterbury Health Laboratories, Christchurch, New Zealand
    PLoS ONE 7:e37883. 2012
  3. pmc Variability of plasma and urine betaine in diabetes mellitus and its relationship to methionine load test responses: an observational study
    Michael Lever
    Biochemistry Unit, Canterbury Health Laboratories, PO Box 151, Christchurch, 8140, New Zealand
    Cardiovasc Diabetol 11:34. 2012
  4. pmc The contrasting relationships between betaine and homocysteine in two clinical cohorts are associated with plasma lipids and drug treatments
    Michael Lever
    Canterbury Health Laboratories, Clinical Biochemistry Unit, Christchurch, New Zealand
    PLoS ONE 7:e32460. 2012
  5. doi request reprint Betaine excretion correlates with plasma homocysteine when plasma lipids are elevated
    Michael Lever
    Clinical Biochemistry Unit, Canterbury Health Laboratories, New Zealand
    Clin Biochem 45:154-6. 2012
  6. ncbi request reprint Fibrates plus betaine: a winning combination?
    Michael Lever
    Biochemistry Unit, Canterbury Health Laboratories, Christchurch, New Zealand
    N Z Med J 123:74-8. 2010
  7. doi request reprint Fibrates may cause an abnormal urinary betaine loss which is associated with elevations in plasma homocysteine
    Michael Lever
    Biochemistry Unit, Canterbury Health Laboratories, P O Box 151, Christchurch, 8140, New Zealand
    Cardiovasc Drugs Ther 23:395-401. 2009
  8. pmc Plasma lipids and betaine are related in an acute coronary syndrome cohort
    Michael Lever
    Clinical Biochemistry Unit, Canterbury Health Laboratories, Christchurch, New Zealand
    PLoS ONE 6:e21666. 2011
  9. doi request reprint The clinical significance of betaine, an osmolyte with a key role in methyl group metabolism
    Michael Lever
    Biochemistry Unit, Canterbury Health Laboratories, Christchurch, New Zealand
    Clin Biochem 43:732-44. 2010
  10. ncbi request reprint Dietary and supplementary betaine: acute effects on plasma betaine and homocysteine concentrations under standard and postmethionine load conditions in healthy male subjects
    Wendy Atkinson
    Clinical Biochemistry Unit, Canterbury Health Laboratories, Christchurch, New Zealand
    Am J Clin Nutr 87:577-85. 2008

Collaborators

Detail Information

Publications32

  1. doi request reprint Plasma betaine concentrations correlate with plasma cortisol but not with C-reactive protein in an elderly population
    Michael Lever
    Clinical Biochemistry Unit, Canterbury Health Laboratories, Christchurch, New Zealand
    Clin Chem Lab Med 50:1635-40. 2012
    ..We aimed to compare plasma cortisol (a stress marker) and C-reactive protein (an inflammation marker) as statistical predictors of plasma betaine concentrations...
  2. pmc Betaine and secondary events in an acute coronary syndrome cohort
    Michael Lever
    Clinical Biochemistry Unit, Canterbury Health Laboratories, Christchurch, New Zealand
    PLoS ONE 7:e37883. 2012
    ..Betaine insufficiency is associated with unfavourable vascular risk profiles in metabolic syndrome patients. We investigated associations between betaine insufficiency and secondary events in acute coronary syndrome patients...
  3. pmc Variability of plasma and urine betaine in diabetes mellitus and its relationship to methionine load test responses: an observational study
    Michael Lever
    Biochemistry Unit, Canterbury Health Laboratories, PO Box 151, Christchurch, 8140, New Zealand
    Cardiovasc Diabetol 11:34. 2012
    ..The post-methionine load test is reported to be both an independent vascular risk factor and a measure of betaine sufficiency...
  4. pmc The contrasting relationships between betaine and homocysteine in two clinical cohorts are associated with plasma lipids and drug treatments
    Michael Lever
    Canterbury Health Laboratories, Clinical Biochemistry Unit, Christchurch, New Zealand
    PLoS ONE 7:e32460. 2012
    ..Urinary betaine excretion positively correlated with plasma homocysteine in outpatients attending a lipid disorders clinic (lipid clinic study). We aimed to confirm this in subjects with established vascular disease...
  5. doi request reprint Betaine excretion correlates with plasma homocysteine when plasma lipids are elevated
    Michael Lever
    Clinical Biochemistry Unit, Canterbury Health Laboratories, New Zealand
    Clin Biochem 45:154-6. 2012
    ..To reconcile observing a positive correlation of betaine excretion with homocysteine in lipid disorder patients but not other study groups...
  6. ncbi request reprint Fibrates plus betaine: a winning combination?
    Michael Lever
    Biochemistry Unit, Canterbury Health Laboratories, Christchurch, New Zealand
    N Z Med J 123:74-8. 2010
    ..Clinical trials of combinations of betaine and fibrate, to complement statin therapy, are needed to determine the value of these agents in reducing the residual cardiovascular disease risk...
  7. doi request reprint Fibrates may cause an abnormal urinary betaine loss which is associated with elevations in plasma homocysteine
    Michael Lever
    Biochemistry Unit, Canterbury Health Laboratories, P O Box 151, Christchurch, 8140, New Zealand
    Cardiovasc Drugs Ther 23:395-401. 2009
    ..These patients are often treated with fibrates which alter renal function and raise plasma homocysteine concentrations. We suggest there is a connection between fibrate treatment and betaine excretion...
  8. pmc Plasma lipids and betaine are related in an acute coronary syndrome cohort
    Michael Lever
    Clinical Biochemistry Unit, Canterbury Health Laboratories, Christchurch, New Zealand
    PLoS ONE 6:e21666. 2011
    ..We aimed to measure the relationships between plasma and urine betaine and plasma lipids, and the effects of lipid-lowering drugs on these...
  9. doi request reprint The clinical significance of betaine, an osmolyte with a key role in methyl group metabolism
    Michael Lever
    Biochemistry Unit, Canterbury Health Laboratories, Christchurch, New Zealand
    Clin Biochem 43:732-44. 2010
    ..Slower HPLC methods give comparable results. Proton NMR spectrometry is another option but caution is needed to avoid confusion with trimethylamine-N-oxide...
  10. ncbi request reprint Dietary and supplementary betaine: acute effects on plasma betaine and homocysteine concentrations under standard and postmethionine load conditions in healthy male subjects
    Wendy Atkinson
    Clinical Biochemistry Unit, Canterbury Health Laboratories, Christchurch, New Zealand
    Am J Clin Nutr 87:577-85. 2008
    ..Betaine comes from the diet and from choline, and it is associated with vascular disease in some patient groups. Betaine supplementation lowers plasma total homocysteine...
  11. ncbi request reprint Homocysteine, glycine betaine, and N,N-dimethylglycine in patients attending a lipid clinic
    Michael Lever
    Biochemistry Unit, Canterbury Health Laboratories, PO Box 151, Christchurch, New Zealand
    Metabolism 54:1-14. 2005
    ..50), and this relationship may be stronger in patients with known vascular disease. Urinary loss of glycine betaine may contribute to hyperhomocysteinemia and the development of cardiovascular disease...
  12. doi request reprint Coenzyme Q10: an independent predictor of mortality in chronic heart failure
    Sarah L Molyneux
    Clinical Biochemistry Unit, Canterbury Health Laboratories, Christchurch, New Zealand
    J Am Coll Cardiol 52:1435-41. 2008
    ..The aim of this study was to investigate the relationship between plasma coenzyme Q(10) (CoQ(10)) and survival in patients with chronic heart failure (CHF)...
  13. ncbi request reprint Dimethylglycine supplementation does not affect plasma homocysteine concentrations in pre-dialysis chronic renal failure patients
    Sandy Slow
    Biochemistry Unit, Canterbury Health Laboratories, PO Box 151 Christchurch, New Zealand
    Clin Biochem 37:974-6. 2004
    ..To determine whether daily dimethylglycine supplementation affects plasma homocysteine concentrations...
  14. ncbi request reprint Betaine supplementation decreases post-methionine hyperhomocysteinemia in chronic renal failure
    David O McGregor
    Department of Nephrology, Christchurch Hospital and School of Medicine, Private Bag 4710, Christchurch, New Zealand
    Kidney Int 61:1040-6. 2002
    ..Glycine betaine (GB) is known to decrease tHcy in other clinical settings, but whether it is beneficial in chronic renal failure has not been established...
  15. ncbi request reprint Effects of orange juice and proline betaine on glycine betaine and homocysteine in healthy male subjects
    Wendy Atkinson
    Clinical Biochemistry Unit, Canterbury Health Laboratories, PO Box 151, Christchurch, New Zealand
    Eur J Nutr 46:446-52. 2007
    ..Proline betaine (PB), a glycine betaine (GB) analogue found in citrus foods, increases urinary GB loss and plasma total homocysteine (tHcy) concentrations in rats. Its presence in human plasma is associated with increased GB excretion...
  16. doi request reprint Plasma and urine betaine and dimethylglycine variation in healthy young male subjects
    Michael Lever
    Biochemistry Unit, Canterbury Health Laboratories, Christchurch, New Zealand
    Clin Biochem 42:706-12. 2009
    ..We aimed to compare the individuality (within subject consistency) of plasma and urine betaine and N,N-dimethylglycine...
  17. ncbi request reprint Sex differences in the control of plasma concentrations and urinary excretion of glycine betaine in patients attending a lipid disorders clinic
    Michael Lever
    Clinical Biochemistry Unit, Canterbury Health Laboratories, Christchurch, New Zealand
    Clin Biochem 40:1225-31. 2007
    ..To find whether the control of betaine metabolism differs between male and female patients and identify the effects of insulin and other hormones...
  18. ncbi request reprint Betaine analogues alter homocysteine metabolism in rats
    Sandy Slow
    Biochemistry Unit, Canterbury Health Laboratories, PO Box 151, Christchurch, New Zealand
    Int J Biochem Cell Biol 36:870-80. 2004
    ..The study shows that glycine betaine analogues have multiple effects on homocysteine metabolism (250)...
  19. ncbi request reprint Coenzyme Q10; an adjunctive therapy for congestive heart failure?
    Sarah L Molyneux
    Biochemistry Unit, Canterbury Health Laboratories, Christchurch, New Zealand
    N Z Med J 122:74-9. 2009
    ..CoQ10 depletion may also be a contributory factor for why statin intervention has not improved outcomes in CHF. There is an emerging evidence base in support of CoQ10 as an adjunctive therapy in CHF...
  20. ncbi request reprint Inter- and intra-individual variations in normal urinary glycine betaine excretion
    Michael Lever
    Clinical Biochemistry Unit, Canterbury Health Laboratories, Christchurch School of Medicine and Health Sciences, Christchurch, New Zealand
    Clin Biochem 40:447-53. 2007
    ..To establish whether normal human subjects excrete glycine betaine at a constant rate...
  21. ncbi request reprint Validation of (1)H NMR spectroscopy as an analytical tool for methylamine metabolites in urine
    Martin B Lee
    Biochemistry Unit, Canterbury Health Laboratories, P O Box 151, Christchurch, New Zealand Department of Chemistry, University of Canterbury, Christchurch, New Zealand
    Clin Chim Acta 365:264-9. 2006
    ..These compounds are all suitable for quantification by (1)H NMR spectroscopy as they all have methyl protons...
  22. ncbi request reprint Separation of cationic aracyl derivatives of betaines and related compounds
    Malina K Storer
    Biochemistry Unit, Canterbury Health Laboratories, P O Box 151, Christchurch, New Zealand
    J Chromatogr A 1104:263-71. 2006
    ..Retention is reduced by increasing the water content and the buffer concentration. Capillary electrophoresis migration times are affected by the choice of buffer anion, with low pH citrate buffers favoured...
  23. ncbi request reprint Short and long-term variation of plasma glycine betaine concentrations in humans
    Michael Lever
    Biochemistry Unit, Canterbury Health Laboratories, Christchurch, New Zealand
    Clin Biochem 37:184-90. 2004
    ..Glycine betaine is important in cell volume regulation and in remethylating homocysteine, a vascular risk factor...
  24. doi request reprint Measurement of plasma free choline by high performance liquid chromatography with fluorescence detection following derivatization with 1-naphthyl isocyanate
    Christopher J McEntyre
    Biochemistry Unit, Canterbury Health Laboratories, PO Box 151, Christchurch 8140, New Zealand
    Anal Chim Acta 644:90-4. 2009
    ..It has sufficient sensitivity to measure choline in biological materials such as human plasma, and is suitable for processing batches of samples...
  25. ncbi request reprint A nuclear-magnetic-resonance-based assay for betaine-homocysteine methyltransferase activity
    Martin B Lee
    Biochemistry Unit, Canterbury Health Laboratories, PO Box 151, Christchurch, New Zealand
    Anal Biochem 330:199-205. 2004
    ..19+/-0.03 mM with a V(max) of 17+/-0.7 nMol min(-1) mg(-1)...
  26. doi request reprint Betaine structure and the presence of hydroxyl groups alters the effects on DNA melting temperatures
    Madhusudan K Vasudevamurthy
    Biochemistry Unit, Canterbury Health Laboratories, P O Box 151, Christchurch, New Zealand
    Biopolymers 91:85-94. 2009
    ..We suggest that the effect of these solutes depends on structuring the hydration water of DNA, as well as interactions with the DNA structure itself...
  27. ncbi request reprint An abnormal urinary excretion of glycine betaine may persist for years
    Michael Lever
    Clinical Biochemistry Unit, Canterbury Health Laboratories, Christchurch School of Medicine and Health Sciences, Christchurch, New Zealand
    Clin Biochem 40:798-801. 2007
    ..Does abnormal betaine excretion persist?..
  28. ncbi request reprint Dimethylthetin treatment causes diffuse alveolar lung damage: a pilot study in a sheep model of Continuous Ambulatory Peritoneal Dialysis (CAPD)
    Sandy Slow
    Biochemistry Unit, Canterbury Health Laboratories, P O Box 151, Christchurch, New Zealand
    Exp Toxicol Pathol 58:285-90. 2007
    ..Toxicity associated with DMT treatment raises concerns for its use in further studies. However, sub-acute administration of DMT to sheep may provide a useful model of acute alveolar damage...
  29. ncbi request reprint A high performance liquid chromatographic method for the measurement of total carnitine in human plasma and urine
    Christopher J McEntyre
    Biochemistry Unit, Canterbury Health Laboratories, P O Box 151, Christchurch, New Zealand
    Clin Chim Acta 344:123-30. 2004
    ..Advantages of this method include good precision, accuracy and linearity, the use of fluorescence to gain sensitivity, the small sample volume required and a relatively low sample preparation time...
  30. ncbi request reprint Assessment of antimicrobial activity of hydrophilic betaines in osmotically stressed bacteria
    Barbara A Peddie
    Department of Nephrology, Christchurch Hospital, Private Bag 4710, Christchurch, New Zealand
    Antonie Van Leeuwenhoek 83:175-81. 2003
    ..4-Methylthiazolium betaine was the only one that showed significant antibacterial activity towards Escherichia coli under hyperosmotic conditions. None of the tested betaines showed any evidence of osmoprotection or urea protection...
  31. ncbi request reprint Biological variation of coenzyme Q10
    Sarah L Molyneux
    Canterbury Health Laboratories, Christchurch, New Zealand
    Clin Chem 51:455-7. 2005
  32. ncbi request reprint Using high-performance liquid chromatography to measure the effects of protein-stabilizing cosolvents on a model protein and fluorescent probes
    Michael Lever
    Biochemistry Unit, Canterbury Health Laboratories, University of Canterbury, Christchurch, New Zealand
    Anal Biochem 367:122-33. 2007
    ..The results with the automated system are consistent with the known stabilizing effects of the cosolvents and validate it as a tool to explore the development of novel cosolvents and their effects on multiple biological systems...