University of North Florida
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Stuart Chalk, Ph.D.
Department of Chemistry
University of North Florida
Phone: 1-904-620-1938
Fax: 1-904-620-3535
Email: schalk@unf.edu
Website: @unf

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Martyn G. Boutelle

Abbrev:
Boutelle, M.G.
Other Names:
Address:
Department of Chemistry, King's College London, Strand, London WC2R 2LS, UK
Phone:
+44 207 848 2638
Fax:
+44 207 848 2810

Citations 6

"Resolving Dynamic Changes In Brain Metabolism Using Biosensors And On-line Microdialysis"
Trends Anal. Chem. 2003 Volume 22, Issue 8 Pages 487-497
Mark C. Parkin

Abstract: A tight coupling exists in the brain between the activity of neurons, the energetic consequences of this activity and the local blood flow. This makes the monitoring of the levels of energy metabolites, such as glucose and lactate, in the fluid surrounding the neurons a particularly effective means of studying brain function. This review outlines why rapid monitoring of brain metabolism in vivo is effective, and demonstrates how the in vivo techniques of implanted biosensors and on-line microdialysis can be used to study the brain in the laboratory and in brain-injury patients.

"Physiological Stimulation Increases Nonoxidative Glucose Metabolism In The Brain Of The Freely Moving Rat"
J. Neurochem. 1993 Volume 60, Issue 4 Pages 1258-1263
Fellows LK, Boutelle MG, Fillenz M.

Abstract: The effects of mild stress on nonoxidative glucose metabolism were studied in the brain of the freely moving rat. Extracellular lactate levels in the hippocampus and striatum were monitored at 2.5-min intervals with microdialysis coupled with an enzyme-based flow injection analysis system. Ten minutes of restraint stress led to a 235% increase in extracellular lactate levels in the striatum. A 5-min tail pinch caused an increase of 193% in the striatum and 170% in the hippocampus. Local application of tetrodotoxin in the striatum blocked the rise in lactate following tail pinch and inhibited the subsequent clearance of lactate from the extracellular fluid. Local application of the noncompetitive N-methyl-D-aspartate receptor antagonist MK-801 had no effect on the tail pinch-stimulated increase in lactate in the striatum. These results show that mild physiological stimulation can lead to a rapid increase in nonoxidative glucose metabolism in the brain.
Glucose Brain Dialysis

"New Technologies For Amperometric Biosensors"
J. Mol. Recognit. 1996 Volume 9, Issue 5-6 Pages 664-671
Martyn G. Boutelle *, H. Allen, O. Hill, Manfred Berners, R. John, P. D. Dobson, P. Leigh

Abstract: Amperomeric-based detectors have successfully been used as personal monitors for blood glucose levels. However, there is a desire to increase the number of compounds measured in a small blood sample, the speed of detection and enhance the reliability of the measurement. Furthermore, with the increasing use of microdialysis as a clinical sampling method in metabolic medicine, paediatric medicine and neurointensive care, there is a need for rapid online detection of analytes such as lactate, glucose and glutamate in low microlitre volume samples. Two approaches to these problems are described. The first uses enzymes immobilized in a packed bed with electrochemical detection of a ferrocene mediator as a flow injection assay for use with microdialysis. Results from microdialysis of the brain of freely moving rats are described. In the second approach, thin-film techniques are used to fabricate arrays of microdisk and microline electrodes. The properties of these arrays in free solution and in a flow cell are presented together with an example using multiple arrays to identify an analyte by oxidation potential. Finally, different enzymes are entrapped onto the surface of two arrays by electrochemical polymerization of o-phenylenediamine. The resulting device detects glucose and lactate in real-time.
Glucose Glutamate Lactate Blood Amperometry Sensor Dialysis

"On-line Monitoring In Neurointensive Care - Enzyme-based Electrochemical Assay For Simultaneous, Continuous Monitoring Of Glucose And Lactate From Critical Care Patients"
J. Electroanal. Chem. 2002 Volume 538, Issue 1 Pages 243-252
D. A. Jones, M. C. Parkin, H. Langemann, H. Landolt, S. E. Hopwood, A. J. Strong and M. G. Boutelle

Abstract: This paper describes the development, verification and use of the first dual on-line electrochemical assay system for use with clinical microdialysis. The assay is a flow injection assay using mediated enzyme beds with electrochemical detection. The on-line assay has been specifically designed for use with head trauma patients in neurointensive care, allowing simultaneous measurement of the levels of glucose and lactate present in the dialysate with high time resolution (30 s sampling intervals). The assay is compared with the Yellow Springs 2300 glucose/lactate analyzer. in simple analyzes and during zero net flux experiments. The on-line assay has greater accuracy and precision particularly at low concentrations of glucose and lactate. The rapid nature of this dual on-line system makes it valuable in studying the roles of energy metabolites in the brain extracellular fluid (ECF), and as an important new method for routine clinical monitoring of patients in the neurointensive care unit. Data is shown for monitoring during surgery and in intensive care. (C) 2002 Elsevier Science B.V. All rights reserved.
Dialysis

"Development And Comparison Of Biosensors For In-vivo Applications"
Faraday Discuss. 2000 Volume 2000, Issue 116 Pages 291-303
Dimitra G. Georganopoulou, Robert Carley, Deborah A. Jones, Martyn G. Boutelle

Abstract: Electrochemical biosensors have been of increasing interest, especially those developed to be directly applied in diagnostic areas, such as neuroscience. We have been interested in developing a range of biosensors for monitoring glucose, lactate, pyruvate, and glutamate in order to study on-line both brain function in the laboratory and to monitor brain health in neurointensive care. For a biosensor to function effectively in these situations, it has to combine the following characteristics: quick response and high sensitivity, good reproducibility and adequate stability. In this study we compared the performance of a number of different amperometric biosensors strategies. These included ferrocene mediation of immobilized enzymes (system A), a redox hydrogel based system (system B), and a conducting polymer approach using polyaniline (system C). All assays were operated as flow injection systems with upstream immobilized enzyme beds if necessary. When calibrated for H2O2 systems A and B reacted quickly enough to give quantitative conversion up to 0.2 mM. Above this concentration the response was limited by horseradish peroxidase enzyme kinetics and eventually enzyme loading. System C showed a restricted H2O2 response. When calibrated for glucose (by use of immobilized glucose oxidase) system B exhibited the highest sensitivity but its analytical range was restricted because the system became limited by H2O2 response. System A had low sensitivity for analyte compared to H2O2 and system B, but a greater useful range. Problems of mediator cycling between the immobilized enzymes are discussed. System C gave an excellent linear range but sensitivity was limited by background noise. Stability and reproducibility of the systems are also described. In conclusion, from this study the ferrocene system proved to be overall most useful and has now been used in the first dual on-line monitoring of glucose and lactate in patients in neurointensive care.

"Enzyme Packed Bed System For The Online Measurement Of Glucose, Glutamate And Lactate In Brain Microdialysate"
Anal. Chem. 1992 Volume 64, Issue 17 Pages 1790-1794
Martyn G. Boutelle, Lesley K. Fellows, and Colin Cook

Abstract: An automated immobilized enzyme-based flow injection assay system is described which uses oxidase and peroxidase to convert the analyte into an oxidized ferrocene species which is assayed by HPLC with reductive electrochemical detection. Glucose oxidase, glutamate oxidase, lactate oxidase and horse-radish peroxidase were immobilized on to tresyl-activated silica beads (10 µm, 500 and 1000 Å). A HPLC guard column (2 cm x 2 mm) was packed with the beads and connected to a HPLC pump and an online microdialysis system, used to control sampling. The mobile phase was 0.05 M Na2HPO4 - 0.5 mM ferrocenemonocarboxylic acid - 1 mM EDTA adjusted to pH 7 with HCl. The assays have detection limits of 1.8 to 20 pmol and were configured to have linear calibration responses over the range of basal and stimulated levels of glucose, glutamate and lactate in microdialysate samples from rat striatum. The assays were carried out at 2.5-min intervals. Rapid measurement of glucose, glutamate, and lactate is important in understanding the dynamics of the energy balance of the brain. Glutamate is also the main excitatory neurotransmitter. A general immobilized enzyme-based flow injection assay system is described which uses oxidase and peroxidase enzymes to convert the analyte into an oxidized ferrocene species which is detected electrochemically by reduction. The enzymes glucose oxidase, glutamate oxidase, lactate oxidase, and horseradish peroxidase are immobilized with near 100% efficiency onto 10-microns tresyl-activated silica beads (1000- and 500-A pore size). The beads are slurry-packed into 2- x 20-mm columns to give beds for glucose, glutamate, or lactate which are stable for greater than 40 days. The flow injection assays described have detection limits from 1.8 to less than 20 pmol and have been configured to have linear calibration responses over the range of basal and stimulated levels of the three compounds found in 5 µL microdialysate samples from the rat striatum. The assays are used for automated online measurement of glucose, glutamate, and lactate in striatal microdialysate at 2.5-min intervals.
Glucose Glutamate Lactate Brain Electrochemical analysis Immobilized enzyme Dialysis