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HPLC and LC-MS/MS methods for diagnosis of inherited metabolic diseases
Bártl, Josef ; Jelínek, Ivan (advisor) ; Čabala, Radomír (referee) ; Cvačka, Josef (referee)
This dissertation thesis is focused on development and optimization of high- performance liquid chromatography (HPLC) and tandem mass spectrometry (LC-MS/MS) methods, and its utility for diagnosis of inherited metabolic diseases. The first thematic part describes a comprehensive laboratory approach to diagnostics of patients with hereditary xanthinuria by determination of specific markers and enzyme activity. For this purpose HPLC method with diode array detection for measurement of hypoxanthine, xanthine, allopurinol and oxypurinol in urine and plasma and HPLC method with fluorimetric detection for analysis of pterin and isoxanthopterin in plasma were employed. These methods were successfully applied in clinical practice to ascertain two patients with hereditary xanthinuria type I. The second thematic part aims at developing and clinical application of new LC-MS/MS method for simultaneous determination of total homocysteine (tHcy), methionine (Met) and cystathionine (Cysta) in dried blood spots (DBS) and plasma. The results demonstrated the clinical utility of this method for detection of patients with homocystinuria and possibility to distinguish between defects in the remethylation and transsulfuration pathways of homocysteine metabolism. Due to ease of DBS collection and sample transportation...
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Central insulin signaling and phosphorylation of Tau protein in rat model of type 2 diabetes
Kasperová, Barbora Judita ; Čabala, Radomír (advisor) ; Mládková, Jana (referee)
Diabetes mellitus 2. typu (DM2) a Alzheimerova nemoc (AN) jsou jedny z nejzávažnějších nemocí naší doby. Právě DM2, spolu s obezitou a nedostatkem pohybu jsou jedny z nejrizikovějších faktorů vedoucí k poruchám kognitivních funkcí a rozvoji demence. Při rozvoji AN dochází k patologickým změnám v mozku. Dochází ke vzniku nerozpustných extracelulárních plaků amyloidního beta peptidu a hyperfosforylaci proteinu Tau. Tato bakalářská práce studuje inzulínovou signalizační kaskádu a fosforylaci proteinu Tau v hipokampech 12ti týdenních ZDF (Zucker Diabetic Fatty) potkanů, zvířecím modelu DM2, v brzkém věku života. Z inzulínové signalizační kaskády bylo detekováno signifikantně nižší množství inzulínového receptoru v hipokampech ZDF potkanů ve srovnání s kontrolami. U ostatních kinas této kaskády (PDK-1, Akt) nebyl nalezen rozdíl jak v celkovém, tak fosforylovaném/aktivovaném proteinu v hipokampech ZDF potkanů a kontrol. Rovněž u fosforylace/aktivace kinas proteinu Tau (GSK-3β, ERK, JNK) a fosforylace/aktivace proteinu Tau na několika epitopech (Ser396, Thr212, Thr231) nebyly pozorovány žádné signifikantní rozdíly mezi ZDF potkany a kontrolami. V hipokampech 12ti týdenních ZDF potkanů, ačkoliv silně hyperglykemických a obézních, nebyly zaznamenány změny v efektivitě inzulínové signalizační kaskády ani...
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Development of analytical methods for determination of phosphorylated components of bacterial cell membranes
Mikulecká, Jana ; Čabala, Radomír (advisor) ; Feltl, Ladislav (referee)
Phospholipids are dominant components of bacterial cell membranes, where they create double layers. Bacteria differ in their phospholipid composition determination of which can help in identification of important groups of microorganisms. Phospholipid composition of bacteria is influenced by many environmental factors, therefore its variation can be observed within one bacterial stem also. Because of its simplicity, thin layer chromatography is usually applied to identification and determination of bacterial phospholipids. Disadvantage of this method are the high demands of time, carefulness and skills of the analytical personnel. The increasing interest in the phospholipid double-layer promotes the detailed investigation of their fatty acid composition because the more detailed analyses allows for more information yield about bacteria. Gas chromatography hyphenated with mass spectrometry seems to be the best choice for these purposes. Fatty acid identity and total fatty acid content in phospholipid molecules could be determined by this method. Additionally, number, position and isomerism of double bonds and presence of other functional groups on hydrocarbon chain could be determined. Whereas a suitable and...
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Structure and reactivity of anions of aromatic hydrocarbons
Obluková, Michaela ; Čabala, Radomír (advisor) ; Jašík, Juraj (referee)
This bachelor thesis deals with research about negative ions reactivity of aromatic hydrocarbons which occur in Titan's ionosphere - Saturn's moon. As an experimental method there was used tandem mass spectrometry with electrospray ionization technique, quadrupole mass analyzer and collision cell. The aim of this thesis was to contribute to the general understanding of processes in the Titan's ionosphere. Particularly there were performed experimental studies to created isomeric benzyne radical anions (o-, m-, p- C6H4˙- ) which were generated from phthalic, isophthalic and terephthalic acid and subsequently their reactions were explored with selected neutral gases in collision cell (C2H2, HC3N, CH3CN, SO2, O2).
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Determination of chlorobenzoic acids in environmental samples using separation techniques with mass detection
Hostačná, Lucie ; Bosáková, Zuzana (advisor) ; Čabala, Radomír (referee)
Chlorobenzoic acids are a major environmental contaminant. The main source of contamination of environmental matrix is a bacterial dergadation of polychlorinated biphenyls. In this work, it has been optimized a method for the determination of 15 chlorobenzoic acid derivates (2-CBA; 3-CBA; 4-CBA; 2,3-CBA; 2,4- -CBA; 2,5-CBA; 2,6-CBA; 3,4-CBA; 3,5-CBA; 2,3,5-CBA; 2,3,6-CBA; 2,4,6- -CBA; 2,3,4,5-CBA; 2,3,5,6-CBA a 2,3,4,5,6-CBA) in the soil matrix, including accelerated solvent extraction, purification by gel permeation chromatography, derivatization and subsequent quantification of samples by GC/MS. As the extraction conditions were used: an extraction mixture of 1% acetic in hexane/acetone (1:1 V/v), temperature by 150 řC, pressure by 10,34 MPa. For purification by gel permeation chromatography solvent was used dichloromethane. Derivatization with diazomethane was determined in the range of 83,7 to 110,6 % with relative standard deviation from 2,1 to 14,2 %. Aplication of the optimized method of the artificially contaminated soil samples in the analysis of GC/MS provided the yield of all analytes in the range of 91,7 to 132,5 % with relative standard deviation from 2,1 to 12,1 %. Validation of methods after aplication to GC/MS gave the analytes 2- -CBA; 3-CBA; 4-CBA and 2,3,4,5-CBA the limit of...
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Development of separation methods for determination of perfluoroalkyl carboxylic acids in envirnonmental samples
Dufková, Veronika ; Čabala, Radomír (advisor) ; Feltl, Ladislav (referee) ; Kubinec, Róbert (referee)
A complete, sensitive and selective procedure was developed for gas chromatographic determination of perfluoroalkyl carboxylic acids (PFCAs, C5 - C12) in river water samples. A rapid and simple derivatization procedure was developed and optimized at first, using isobutyl chloroformate (IBCF) to convert the acids into the more volatile isobutyl esters. The second task was to find the most suitable stationary phase for separation of perfluoroalkyl carboxylic acids by GC. The retention characteristics of PFCA isobutyl esters were measured and compared on 9 different stationary phases. The physical-chemical parameters of analyte interactions with stationary phase were monitored on selected column Rtx-200MS, and these parameters were compared with a non-fluorinated homologue - octanoic acid. A sensitive GC-MS system was used with negative chemical ionization, which is suitable for the selected type of fluorinated analytes. The developed method exhibits very low limits of detection and determination of PFCA isobutyl esters: 0.05 - 9.7 ng mL-1 (LOD) and 0.16 - 32.2 ng mL-1 (LOQ). An optimum pre-concentration technique was found for real water samples, where SPE SupelTM-Select HLB cartridges were used. In these cartridges, PFCAs were captured as ion- pairs with enrichment factor of 400. The recoveries of...
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Determination of Sibiromycin by UPHLC Method
Šestáková, Ivana ; Čabala, Radomír (referee)
A new separation and quantification method using ultra high-performance liquid chromatography (UHPLC) with UV detection was developed for the detection of sibiromycin in fermentation broth of Streptosporangium sibiricum. The solid phase extraction method based on cation-exchange was employed to pre-concentrate and purify fermentation broth containing sibiromycin prior to UHPLC analysis. The whole assay was validated and showed a linear range of detector response for the quantification of sibiromycin in a concentration from 3.9 to 250.0 µg/ml, with correlation coefficient of 0.999 and recoveries rating from 71.66±3.55 % to 74.75±5.18 %. Method limit of quantification of the assay was determined as 0.18 µg/ml and was verified with resulting RSD of 9.6 % and accuracy of 97.6 %. The developed assay was used to determine the sibiromycin production in 12 different fermentation broths. Moreover, several natural sibiromycin analogues/derivatives were described with pilot characterization using off-line mass spektrometry.
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Analysis of pterine derivatives by capillary zone electrophoresis
Krajíček, Jan ; Bosáková, Zuzana (advisor) ; Čabala, Radomír (referee)
Pterins belong to an important group of compounds, acting as inhibitors, sensiziters, enzymes, coenzymes, pigments etc. and together with carotenoids and anthraquinones are responsible for characteristic coloration of bugs. This work was focused on the development of a capillary electrophoretic separation method for the analysis of six pterine derivatives, namely biopterine, neopterine, isoxanthopterine, leukopterine, xanthopterine and erythropterine and on their identification in the real samples. Separation was conducted in an uncoated fused-silica capillary termostated at 30 řC. Separation electrolyte contained boric acid, tris(hydroxymethyl)aminomethane and disodium salt of ethylenediaminetetraacetic acid. The effects of buffer pH, concentration of electrolyte components, separation voltage and wavelength of UV detection on electromigration behavior and detection sensitivity were studied. Under the optimized separation conditions, organic extracts of the three forms of Graphosoma semipunctatum bugs were analyzed.
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Determination of selected chromatographic and thermodynamic parameters of perfluorinated organic acids by gas chromatography
Vrzal, Tomáš ; Čabala, Radomír (advisor) ; Pacáková, Věra (referee)
Chromatographic and thermodynamic parameters (specific retention volume, distribution coefficient, standard molar enthalpy, entropy and Gibbs energy) has been determined for retention of isobutyl esters of homological set of perfluorinated carboxylic acids C6 - C12 on the fluorinated stationary phase Rtx-200MS. Determined data has shown, that distribution of solutes between stationary and mobile phase is driven neither by the enthalpy nor entropy, but both these contributors play the same role in the retention mechanism. Helium and hydrogen has been used as a mobile phases during analysis. Their influence on thermodynamic behavior of isobutyl esters of PFCAs is insignificant.
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