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Aš, Czech Republic

Chlup R.,Palacky University | Chlup R.,Institute of Neurology and Geriatrics | Krejci J.,BVT Technologies | O'Connell M.,Probe Scientific | And 10 more authors.
Biomedical Papers | Year: 2015

Aim. The aim of this pilot study was to acquire insight into the parameters of glycaemic control, especially, (1) the time delay (lag phase) between plasma and tissue glucose concentrations in relation to rise and fall in glucose levels and (2) the rate of glucose increase and decrease. Methods. Four healthy people (HP), 4 people with type 1diabetes (DM1) and 4 with type 2 diabetes (DM2) underwent concurrent glucose measurements by means of (1) the continuous glucose monitoring system (CGMS-Medtronic), Medtronic-Minimed, CA, USA, calibrated by the glucometer Calla, Wellion, Austria, and, (2) the Beckman II analyser to measure glucose concentrations in venous plasma. Samples were taken on 4 consecutive days in the fasting state and 4 times after consumption of 50 g glucose. Carelink Personal, MS Excel, Maple and Mat lab were applied to plot the evolution of glucose concentration and analyse the results. The time difference between increase and decrease was calculated for HP, DM 1 and DM 2. Results. In DM1and DM2, glucose tolerance testing (GTT) resulted in slower transport of glucose into subcutaneous tissue than in HP where the lag phase lasted up to 12 min. The maximum increase/decrease rates in DM1 and DM2 vs HP were 0.25 vs < 0.1 mmol/L/min. Conclusion. CGMS is shown to provide reliable plasma glucose concentrations provided the system is calibrated during a steady state. The analysis of glucose change rates improves understanding of metabolic processes better than standard GTT. © 2015, PALACKY UNIV. All rights reserved.

Krejci J.,BVT Technologies | Sajdlova Z.,BVT Technologies | Nedela V.,Academy of Sciences of the Czech Republic | Flodrova E.,Academy of Sciences of the Czech Republic | And 3 more authors.
Journal of the Electrochemical Society | Year: 2014

The article compares the determination of an SPE (Screen Printed Electrodes) electrochemical active surface (AS) by the analysis of cyclic voltammogram in ferro-ferricyanide using Koutecky equation and by confocal and electron microscopy. SPE reliability is influenced by mass transport of analyte to active electrode surface while the physical properties of SPE are reproducible and stable. The electrode reaction involves the upper layer of SPE. The AS is the same as the geometrical area. Other methods set the active/geometrical area relation to 2,03 ± 0,04 (gold working electrode) and 4,35 ± 0,08 (platinum working electrode). It is demonstrated that nanostructures on working electrode surface can be efficient at high frequencies (>10 kHz). The active area of SPE determined by scanning electron microscopy or optical measurement exhibits a standard deviation lower than 2%. It proves SPE be reliable and precise electrochemical device under optimal hydrodynamic conditions. © 2014 The Electrochemical Society.

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