|
Diffusion parameters of brain tissue during ischemia and during status epilepticus
Šlais, Karel ; Syková, Eva (advisor) ; Otáhal, Jakub (referee) ; Rokyta, Richard (referee) ; Dezortová, Monika (referee)
Difusion of neuroactive substances in the extracellular space (ECS) is constrained by two factors: extracellular space volume and geometry. We have shown changes of diffusion parameters and extracellular concentrations of energetic metabolites and glutamate in two pathological states accompanied by significant ECS volume changes - in combined hypoxia/ischemia and in status epilepticus. In the model of hypoxia/ischemia, we have shown time courses of diffusion parameters, concentrations of glucose, lactate, lactate/pyruvate ratio and glutamate during hypoxic/ischemic insult and after reperfusion. The time course of glutamate extracellular concencetration in transient hypoxia/ischemia correlated well with time course of changes in diffusion parameters. The decrease in the ECS volume fraction can therefore contribute to an increased accumulation of toxic metabolites, which may aggravate functional deficits and lead to damage of the central nervous system. In the model of pilocarpine-induced status epilepticus our results show changes in the extracellular space diffusion parameters, K+, energy-related metabolites and glutamate during the initiation and first hours of the propagation. Our results also show that the first minutes after a pilocarpine injection are followed by an increase in extracellular K+ and a...
|
|
Evaluation of the 33 synthesized nitrophenol-based markers of isoelectic point
Duša, Filip ; Moravcová, Dana ; Šlais, Karel
33 nitrophenol-based compounds, which absorb at ultraviolet as well as visible wavelengths, were selected as candidates for marking isoelectric points (pI) over the pH range from 3 to 10. The evaluation and selection of the candidate structures included structure-based calculations of acid-base properties. The selected compounds were further tested experimentally using capillary isoelectric focusing. The experimental analysis excluded two compounds due to producing double peaks during the analysis. Overall, 31 novel compounds were identified as suitable pI markers.
|
|
Diffusion parameters of brain tissue during ischemia and during status epilepticus
Šlais, Karel ; Syková, Eva (advisor) ; Otáhal, Jakub (referee) ; Rokyta, Richard (referee) ; Dezortová, Monika (referee)
Difusion of neuroactive substances in the extracellular space (ECS) is constrained by two factors: extracellular space volume and geometry. We have shown changes of diffusion parameters and extracellular concentrations of energetic metabolites and glutamate in two pathological states accompanied by significant ECS volume changes - in combined hypoxia/ischemia and in status epilepticus. In the model of hypoxia/ischemia, we have shown time courses of diffusion parameters, concentrations of glucose, lactate, lactate/pyruvate ratio and glutamate during hypoxic/ischemic insult and after reperfusion. The time course of glutamate extracellular concencetration in transient hypoxia/ischemia correlated well with time course of changes in diffusion parameters. The decrease in the ECS volume fraction can therefore contribute to an increased accumulation of toxic metabolites, which may aggravate functional deficits and lead to damage of the central nervous system. In the model of pilocarpine-induced status epilepticus our results show changes in the extracellular space diffusion parameters, K+, energy-related metabolites and glutamate during the initiation and first hours of the propagation. Our results also show that the first minutes after a pilocarpine injection are followed by an increase in extracellular K+ and a...
|
| |
| |
| |
|
New isoelectric focusing power supply based on features of voltage multiplier
Duša, Filip ; Šlais, Karel
Present electrophoretic separation methods rely on sophisticated high-voltage power supplies capable of programing a voltage / current time course during an analysis. In this paper we suggest design of a simple highvoltage power supply for isoelectric focusing composed from affordable and commonly available electrical parts. It is based on features of the voltage multiplier invented by Cockcroft and Walton. Electrical characteristics of the power supply enabled power load controlled isoelectric focusing analysis thus eliminating need for programing voltage time course and reducing analysis total time.
|
| |
|
Micropreparative solution isoelectric focusing of peptides and proteins in nonwoven strip
Duša, Filip ; Šlais, Karel
Recently we devised a new instrument for micropreparative analysis [1]. It is based on solution phase isoelectric focusing (sIEF) performed in a narrow channel (approximately 2 – 4 mm wide) with a strip of nonwoven fabric serving as the analysis bed. The strip can be precut before an analysis to make harvesting of fractions easier. Isoelectric focusing is driven by a programmable electrophoretic power supply. Progress of analysis is monitored by addition of colored isoelectric point (pI) markers. Usually sIEF runs are performed overnight. Evaporation of water is one of crucial features of analysis and it forces free liquid to shrink into the nonwoven fabric strip. Moreover, water evaporation increases liquid viscosity by altering ethylene glycol/water ratio. Fractions can be harvested simply by collecting and washing precut segments after the sIEF run. In this paper we used sIEF device for purification of caseinomacropeptide (CMP) from crude whey. Obtained fractions were further analyzed by HPLC. From acquired data a plot with chromatograms of all fractions was constructed to show purification profile of CMP. We proved that the new instrument is capable of quantitative purification of CMP complex from a globulin fraction.
|
| |