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Electrochemical biosensors with spatially separated enzymatic and detection parts for selective analysis in flow-through arrangement
Tvorynska, Sofiia ; Barek, Jiří (advisor) ; Labuda, Ján (referee) ; Korecká, Lucie (referee)
This dissertation thesis presents the newly developed four highly reusable, stable as well as simple, and cost-effective electrochemical (bi)enzymatic biosensors for the selective and reliable determination of choline, acetylcholine, uric acid, and L-lactic acid in flow injection analysis. All biosensors are based on the concept of the spatial separation of the biorecognition part from detection one and amperometric monitoring of the enzymatically consumed oxygen via its four-electron reduction at the highly negative detection potential. In this way, the design of the biosensors includes an easily replaceable enzymatic mini-reactor(s) connected upstream to the flow cell that contains the appropriate silver amalgam-based transducer. The enzymatic mini-reactor based on choline oxidase, uricase, or lactate oxidase was used for choline, uric acid, or L-lactic acid biosensors, respectively. The acetylcholine bienzymatic biosensor includes the consequently connected choline oxidase- and acetylcholinesterase-based mini-reactors. The first part of this thesis focuses on the construction of two different silver amalgam-based electrodes. Specifically, this section discusses the fabrication of a silver solid amalgam electrode covered by mercury film operating in a wall-jet cell and also highlights the...
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Adaptace centrálního nervového systému na chybění acetylcholinesterázy
Farár, Vladimír ; Mysliveček, Jaromír (advisor) ; Jakubík, Jan (referee) ; Cordero-Erausquin, Matilde (referee)
Acetylcholinesterase (AChE) effectively hydrolyzes acetylcholine (ACh). The inhibition of AChE is generally lethal and mice without AChE in all tissues (AChE KO) have severe impairments. In the brain, AChE is anchored in the plasma membrane by proline-rich membrane anchor (PRiMA), while in the muscles, AChE is anchored by collagen Q (ColQ) in the basal lamina. We report here that the PRiMA KO mice, in which AChE is essentially eliminated in the brain, show very little changes in behavior despite an excess of ACh in the brain and adaptation of ACh receptors comparable to those seen in AChE KO mice. Moreover, when AChE cannot interact with ColQ and PRiMA, the phenotype resembles that of AChE KO mice, but the biochemical changes in the brain are similar to those in PRiMA KO mice. PRiMA KO mice also differ from other AChE-deficit mice strains in their responses to AChE inhibitor. Our results suggest that AChE in the peripheral tissues is the major target of AChE inhibitors and AChE absence in the peripheral tissues is the leading cause of the phenotype of AChE KO mice.
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Expression of cholinergic gene locus in a mouse model of Alzheimer's disease
Zimčík, Pavel
(anglický jazyk) The most common senile dementia, Alzheimer disease (AD), is characterized by a decline of memory and high cognitive functions. Typical post-mortem brain lesions are extracellular amyloid deposits, intracellular neurofibrilary tangles and ruined cholinergic and other neurotransmitters systems. Connection between damaged central cholinergic system and beta-amyloid accumulation remains obscure. We examined parietal cortex of young adult (7- month-old) female APPswe/PS1dE9 double transgenic mice which develope beta-amyloid fragments at high rate. Cholinergic synapses of these mice demonstrate functional presynaptic (stimulated acetylcholine release) as well as postsynaptic (muscarinic receptor-induced Gprotein activation) deficits and reduction of cholinergic markers. The mRNA levels of choline acetyltransferase, vesicular acetylcholine transporter and M1 to M4 subtypes of muscarinic receptors were determined in transgenic and littermate controls using qPCR. Obtained experimental data does not show any changes in measured mRNA levels. These observations indicate that reduction of cholinergic synaptic markers and function is due to posttranscriptional events.
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Cholinergic signaling in the striatum and its significance in cognitive flexibility
Smolík, Matyáš ; Janíčková, Helena (advisor) ; Funda, Jiří (referee)
In the striatum, cholinergic interneurons (CINs) contribute to the control of behaviour, motor and cognitive functions. Recently, number of studies have shown a special significance of CINs in the control of cognitive flexibility: the ability to learn new behavioural strategies when requirements of the environment change. Along with working memory, cognitive inhibition, attention control and other cognitive domains, cognitive flexibility belongs to executive functions. Cognitive flexibility impairment is present in a range of neuropsychiatric disorders and thus, understanding its mechanisms is of outstanding importance. The proposed work will first describe anatomy and cellular composition of the striatum and its functions. It will further describe cholinergic system with a special attention to cholinergic signalling in the striatum. The final chapter of the general part of the thesis will focus on cognitive flexibility. After discussing the involved structures and systems separately, the thesis will eventually provide comprehensive review of currently available studies investigating how striatal CINs contribute to brain's ability to replace old concepts with new and more efficient ones.
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Targeting cholinergic system in tretment of Alzheimer's disease.
Golianová, Nikoleta ; Jakubík, Jan (advisor) ; Říčný, Jan (referee)
Alzheimer's disease (AD) is a neurodegenerative disorder of CNS and very serious type of dementia. AD affected 46.8 million people worldwide in 2015, and it is estimated that the number of patients will double every 20 years, reaching over 130 million people in 2050 according to Alzheimer's Disease International. There are two forms of the AD: familial (FAD) and sporadic (SAD) form. FAD is an early-onset disease caused by genetic mutations. SAD is more common, a late-onset disease with the age and ε allele of apolipoprotein E as major risk factors. The most crucial symptom is memory disorder, followed by disorientation, confusion, depression and later on, serious psychical and motor-skill problems. These symptoms are the result of a neuronal loss due to formation of β-amyloid oligomers and neurofibrillary tangles in the central nervous system (CNS). As for now, there are neither efficient diagnostic approaches, nor therapeutic ways to stop the degeneration of the brain. There are some drugs available, such as inhibitors of acetylcholinesterase, that have proven to slow down the progression of the AD. Other cholinergic approaches have been developed, but they have shown a lot of side effects, as they are targeting a large scale of receptors. Additional approaches are focusing on clearance of -...
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Cholinergic system as pharmacological target in Alzheimer's disease
Golianová, Nikoleta ; Jakubík, Jan (advisor) ; Telenský, Petr (referee)
Alzheimer's disease (AD) is a neurodegenerative disorder of CNS and very serious type of dementia. AD affects many elderly people and the numbers are increasing with every year. There are two forms of AD: familial (FAD) and sporadic (SAD) form. FAD is an early-onset disease with a genetic cause. SAD is more common, late-onset disease with the age and ε allele of apolipoprotein E as major risk factors. The most crucial symptom is memory disorder, followed by confusion, disorientation, depression and later on, serious psychical and motor-skill problems. These symptoms are as result of neuronal loss, plaques and tangles in the central nervous system (CNS). As for now, there are no efficient diagnostic or therapeutic approaches to stop the degeneration of brain. Inhibitors of acetylcholinesterase are currently the only approved treatments, that have proven to slow down the progress of AD. Other cholinergic drugs have been developed, but they have shown a lot of side effects, as they are targeting a large scale of receptors. The researchers are trying to find a modulator, that would target only specific receptors in the CNS, to avoid such side effects. Key words: acetylcholine, Alzheimer's disease, β-amyloid, cholinergic system, inhibitors of cholinesterase, muscarinic receptors, nicotinic receptors,...
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Chosen Analogues Derived from Substance 7-MEOTA Action on Some Aspects of Cholinergic System
Sedláček, Lukáš ; Říčný, Jan (advisor) ; Hejnová, Lucie (referee)
This thesis deals with effects of some chosen 7-methoxitacrine (7-MEOTA) analogues on enzymatic activity of acetylcholinesterase (AChE). 7-MEOTA is a derivative of tacrine, which had been used for symptomatic treatment of Alzheimer's disease (AD), until drugs with better therapeutic index were developed. 7-MEOTA the same way as tacrine therapeutically acts by inhibition of acetylcholinesterase and a neurotransmitter acetylcholine rise in the organism. It shows similar strength and type of inhibition, but it's less toxic contrary to tacrine. Some of the previously examined analogues of 7-MEOTA were as strong or even stronger AChE inhibitors than 7-MEOTA and so promising future medicaments. However, all the compounds analyzed in this thesis showed weaker enzymatic reaction inhibition and AChE affinity. For each of the examined compounds IC50, Ki and Ki' were calculated and AChE inhibition type was determined. All the 7-MEOTA analogues showed a mixed type of the inhibition. The theoretical part of this thesis deals with manifestations and origins of AD, its genetic factors etc. and tries to show some of the anthropological findings a theories connected with the theme.
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Stanovení acetylcholinu pomocí LC-MS ve vzorcích mozkových mikrodialyzátů LC-MS/MS
Vrobel, Ivo ; Solich, Petr (advisor) ; Kujovská Krčmová, Lenka (referee)
Charles University in Prague Faculty of Pharmacy in Hradec Králové Department of Analytical Chemistry Candidate: Ivo Vrobel Supervisors: Prof. RNDr. Petr Solich, CSc; Department of Analytical Chemistry, Faculty of Pharmacy, Charles University in Prague Prof. Seppo Auriola, MSc.(Chem.) Marko Lehtonen; Department of Pharmaceutical Chemistry, School of Pharmacy, University of Eastern Finland in Kuopio Title of master's thesis: LC-MS/MS analysis of acetylcholine in brain microdialysis samples Novel fast and simple LC-MS/MS method of ACh quantification in brain microdialysis samples utilizing stable-isotope-labeled IS was developed. The chromatographic step is based on revered-phase mode of pentafluorophenylpropyl (PFPP) column. The satisfactory retention of ACh is achieved with highly aqueous mobile phase containing 0.05% of the ion-pairing agent TFA and 4% of ACN in 4 min analytical run. Ionization of ACh and IS with low background noise and tolerant towards use of TFA was performed with atmospheric pressure thermospray ionization (APTSI). The selectivity of ACh and IS detection was obtained by SRM modes of MS/MS in the linear ion trap mass analyzer. The performance of developed method was cross validated to the validated method used in the laboratory for ACh measurements. The set of microdialysis...
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Adaptace centrálního nervového systému na chybění acetylcholinesterázy
Farár, Vladimír ; Mysliveček, Jaromír (advisor) ; Jakubík, Jan (referee) ; Cordero-Erausquin, Matilde (referee)
Acetylcholinesterase (AChE) effectively hydrolyzes acetylcholine (ACh). The inhibition of AChE is generally lethal and mice without AChE in all tissues (AChE KO) have severe impairments. In the brain, AChE is anchored in the plasma membrane by proline-rich membrane anchor (PRiMA), while in the muscles, AChE is anchored by collagen Q (ColQ) in the basal lamina. We report here that the PRiMA KO mice, in which AChE is essentially eliminated in the brain, show very little changes in behavior despite an excess of ACh in the brain and adaptation of ACh receptors comparable to those seen in AChE KO mice. Moreover, when AChE cannot interact with ColQ and PRiMA, the phenotype resembles that of AChE KO mice, but the biochemical changes in the brain are similar to those in PRiMA KO mice. PRiMA KO mice also differ from other AChE-deficit mice strains in their responses to AChE inhibitor. Our results suggest that AChE in the peripheral tissues is the major target of AChE inhibitors and AChE absence in the peripheral tissues is the leading cause of the phenotype of AChE KO mice.
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Chosen Analogues Derived from Substance 7-MEOTA Action on Some Aspects of Cholinergic System
Sedláček, Lukáš ; Říčný, Jan (advisor) ; Hejnová, Lucie (referee)
This thesis deals with effects of some chosen 7-methoxitacrine (7 MEOTA) analogues on enzymatic activity of acetylcholinesterase (AChE). 7-MEOTA is a derivative of tacrine, which had been used for symptomatic treatment of Alzheimer's disease (AD), until drugs with better therapeutic index were developed. 7-MEOTA the same way as tacrine therapeutically acts by inhibition of acetylcholinesterase and a neurotransmitter acetylcholine rise in the organism. It shows similar strength and type of inhibition, but it's less toxic contrary to tacrine. Some of the previously examined analogues of 7-MEOTA were as strong or even stronger AChE inhibitors than 7-MEOTA and so promising future medicaments. However, all the compounds analyzed in this thesis showed weaker enzymatic reaction inhibition and AChE affinity. For each of the examined compounds IC50, Ki and Ki' were calculated and AChE inhibition type was determined. All the 7 MEOTA analogues showed a mixed type of the inhibition. The theoretical part of this thesis deals with manifestations and origins of AD, its genetic factors etc. and tries to show some of the anthropological findings a theories connected with the theme. Powered by TCPDF (www.tcpdf.org)
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