|
|
Study on stability of triazine based herbicides in water
Petrlíková, Kateřina ; Tesařová, Eva (advisor) ; Janečková, Lucie (referee)
The first aim of this thesis was to find a suitable analytical method for monitoring of stability of four s-triazine herbicides in water samples. Two columns - stationary phases C18, namely products of Waters and Astec were tested in HPLC system. The composition of ACN/H2O mobile phase was changed in the range from 90/10 to 60/40 (v/v). Baseline separation of prometone, propazine and prometryne was achieved on the Astec C18 column with mobile phase ACN/H2O 70/30 (v/v). This separation system was used for the study of stability. The stability of s-triazines was monitored in the period of six weeks. The samples of atrazine, prometone, propazine and prometryne water from water tap. All samples were detected at the wavelength of 221nm. No significant changes were found in the contents of s-triazines in the samples were measured in samples of water - water from Vltava, acidified water from Vltava, water from water tap and acidified water from water tap. All samples were detected at the wavelength of 221nm. No significant changes were found in the contents of s-triazines in the samples.
|
|
|
Optimization and validation of analytical method for determination of selected drugs
Geryk, Radim ; Tesařová, Eva (advisor) ; Janečková, Lucie (referee)
The aim of this work was finding suitable conditions for separation of enantiomers of citalopram and citadiol, optimization of chromatographic system and validation of the analytical method for determination of selected enantiomers in drugs. Drugs are often chiral compounds. In many cases, only enantiomer has required pharmacological effects. Advanced chemical technologies associated with the synthesis, separation and analysis of the individual enantiomers caused an increase of the number of new chiral drugs in the form of single pure enantiomers, the chiral switch. Citalopram is one of the widely used antidepressants of selective serotonin reuptake inhibitors (SSRI). Citalopram is used for treatment of depression, panic anxienty or obsessive compulsive disorder of pathological laughing and crying. The pharmacological activity is associated with the S-citalopram, while R-enantiomer is essentially inactive and even counteracts the activity of escitalopram. Citadiol is a chiral syntetic precursor of citalopram. This thesis was focused on monitoring enantioseparation "behaviour" of selected enantiomers. HPLC method with chiral stationary phases based on macrocyclic antibiotics, cyclofructans and cellulose was applied for enantioseparation of the above-mentioned compounds. The optimized chromatographic...
|
|
| |
|
|
Transdifferentiation of somatic cells into hepatocytes and clinical relevant edition of the Tight junction protein 2 gene
Fryntová, Lucie ; Janečková, Lucie (advisor) ; Krylov, Vladimír (referee)
Transdifferentiation induces chromatin reconstructions and epigenetic changes that affect gene expression spectum and cause cell remodeling in general. Direct conversion of mature somatic cell line into another mature cell type occures during the transdifferentiation thereby differences betweeen individual germ layers are eliminated. The aim of the master thesis is transdifferentation of mesenchymal cells - mouse embryonic fibroblast into endodermal cells - hepatocytes in vitro, using combination of transcripion factors Hnf4α and Foxa1. Detection of fibroblasts transformation has been initiated immediately after retroviral transduction and final generation of induced hepatocyte culture was confirmed by morphological and function analysis. The population of mouse induced hepatocytes served as a possible model for human liver disease in case of a pacient whose liver proteins could not be detected immunohistochemically. Genome editing of induced hepatocytes was realized by CRISPR/Cas9 technology which is based on cooperation of guideRNA and Cas9 nuclease followed in addition to generation of DNA-specific double strand breaks. These specific breaks in the Tight junction protein 2 gene were repaired via homologous recombination that induced a missense mutation with amino acid changes in the target...
|
|
|
Characterization of modern HPLC columns and their application potential
Janečková, Lucie ; Tesařová, Eva (advisor) ; Pacáková, Věra (referee) ; Flieger, Miroslav (referee)
(EN) The aim of the dissertation thesis is characterization of modern HPLC columns from the point of their interaction possibilities and demonstration of their application potential. The first part of the thesis is focused on alternative reversed-phase HPLC columns based on zirconium dioxide. These packings offer excellent chemical stability and additional interactions that can be helpful in the development of analytical methods. A detailed study of the chromatographic behaviour of biologically active nonapeptides as model analytes confirmed the substantial effect of mobile phase composition on retention mechanism. Consequently, HPLC separation systems with zirconia-based polystyrene column were characterized by distinct approaches that allowed recognition of the interactions participating in the separation process. Empirically based chromatographic tests evaluated the fundamental properties of the system - hydrophobicity and polarity. The complex model of linear free energy relationship described the prevailing interactions in different separation systems. Application of a set of basic compounds revealed the contribution of ion-exchange interactions participating in the separation systems with zirconia-based column. The second part of the thesis is devoted to new cyclofructan-based chiral...
|
|
| |
|
| |
|
|
Organoids - the phenomenon of complex organ-like structures cultivation in vitro
Vilímková, Veronika ; Janečková, Lucie (advisor) ; Rothová, Olga (referee)
Pluripotent embryonal stem cells (ESCs) are unique for their ability to proliferate and differentiate into almost all cell types. In the presence of appropriate stimuli, they are able to initiate morphogenesis in vitro. Stem cells are able to differentiate into specific cell lines of a given tissue and to arrange three- dimensional (3D) structures. These so-called organoids are formed in a self-organizing process that mimics normal ESCs development. Organ development is a complex process that requires temporally and spatially ordered regulatory signals. 3D organization of these structures allows important cell-cell interactions. Organoid cultures are thus the area of a huge potential. Organoids are accessible to all standard experimental manipulations. They are therefore an ideal tool for the research of stem cells, signaling pathways, organogenesis and disease modeling. Finally, they may open up new avenues for regenerative medicine and gene therapy. Powered by TCPDF (www.tcpdf.org)
|
|
|
Characterization of Modern HPLC Columns and Their Application Potential
Janečková, Lucie
(EN) The aim of the dissertation thesis is characterization of modern HPLC columns from the point of their interaction possibilities and demonstration of their application potential. The first part of the thesis is focused on alternative reversed-phase HPLC columns based on zirconium dioxide. These packings offer excellent chemical stability and additional interactions that can be helpful in the development of analytical methods. A detailed study of the chromatographic behaviour of biologically active nonapeptides as model analytes confirmed the substantial effect of mobile phase composition on retention mechanism. Consequently, HPLC separation systems with zirconia-based polystyrene column were characterized by distinct approaches that allowed recognition of the interactions participating in the separation process. Empirically based chromatographic tests evaluated the fundamental properties of the system - hydrophobicity and polarity. The complex model of linear free energy relationship described the prevailing interactions in different separation systems. Application of a set of basic compounds revealed the contribution of ion-exchange interactions participating in the separation systems with zirconia-based column. The second part of the thesis is devoted to new cyclofructan-based chiral...
|
|
|
Study of the substrate specificity of the LACTB tumour suppressor enzyme
Baudyšová, Alžběta ; Kečkéšová, Zuzana (advisor) ; Janečková, Lucie (referee)
Serine beta-lactamase-like protein (LACTB) is a tumour suppressor that modulates mitochondrial lipid metabolism and induces differentiation of breast cancer cells. This is achieved by the LACTB-dependent downregulation of phosphatidylserine- decarboxylase (PISD) which subsequently leads to decreases in the amounts of phosphatidylethanolamines and lysophosphatidylethanolamines in mitochondrial membranes. However, PISD was shown to not be a direct substrate of the LACTB enzyme what leaves the identity of the LACTB substrate an open question. To fill this important gap in the mechanism of the LACTB tumour suppressive pathway, this diploma thesis was focused on finding a physiological substrate of LACTB via Proteomic Identification of protease Cleavage Sites (PICS) assay. For this purpose, the other sub-aims of this project were to isolate recombinant wild-type LACTB and its catalytic mutant, to reveal ideal in vitro conditions for LACTB activity and to find out the requirements needed for LACTB multimerization. My results show that in vitro activity of LACTB is increased in the presence of higher pH and calcium ions. I also show that higher LACTB multimeric forms are bound together via disulfide bonds as they disintegrate after treatment with dithiothreitol. Furthermore, and most importantly, I show...
|
guest ::
