National Repository of Grey Literature 93 records found  1 - 10nextend  jump to record: Search took 0.01 seconds. 
An identification of selective antagonists of constitutive androstane receptor
Ondraszková, Karolína ; Smutný, Tomáš (advisor) ; Pourová, Jana (referee)
Charles University Faculty of Pharmacy in Hradec Králové Department of Pharmacology and Toxicology Student: Karolína Ondraszková Supervisor: PharmDr. Tomáš Smutný, Ph.D. Title of diploma thesis: An identification of selective antagonists of constitutive androstane receptor The constitutive androstane receptor (CAR) is an important ligand-regulated xenosensor that regulates the transcription of important drug biotransforming enzymes (e.g. CYP2B6). The pregnane X receptor (PXR) belongs to the same family of nuclear receptors as the CAR. The structure and function of both receptors share many common features. However, PXR has a larger and more flexible ligand-binding domain. At present, a selective, highly potent and non- toxic inhibitor of CAR is not practically available. This work aims to determine the affinity of previously identified compounds in our group with antagonistic activity towards CAR. This is a replication study. For this purpose, we tested the compounds using gene reporter and two-hybrid assay. Of all the tested substances, we obtained desired results with substance 1A. Using the gene reporter assay method, we found that substance 1A can reduce basal CAR expression but also suppresses CAR activity induced by the model agonist CITCO. The high affinity of the substance for the...
Synthesis and evaluation of potential drugs for neurodegenerative diseases
Foltýnová, Eva ; Krátký, Martin (advisor) ; Vinšová, Jarmila (referee)
The topic of this thesis is the synthesis of oxadiazole derivatives and their precursors as potential therapeutics for neurodegenerative diseases, and their evaluation primarily as potential inhibitors of cholinesterases (CHE). The theoretical part of this thesis focuses on Alzheimer's disease, particularly its pathophysiology, diagnosis, and treatment. It also discusses CHE inhibitors that are already clinically used, as well as new structures with potential for future clinical use. Additionally, it addresses the oxadiazole fragment, its chemical and biological properties. In the experimental work, derivatives of 1,3,4- and 1,2,4-oxadiazoles were synthesized, which differed not only in the type of oxadiazole but also in their substitution. These substances were prepared by the cyclization of precursors, which were also prepared and tested. For 1,3,4- oxadiazoles, besides their inhibitory activity against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE), their potential antimycobacterial, antibacterial, and antifungal activities were tested. For 1,2,4-oxadiazoles, so far, only their inhibitory activity against AChE and BuChE has been tested. A total of twenty-two substances were synthesized, and the yields of these syntheses ranged from 21-97%. The compound with the lowest IC50 value...
Glycolytic enzymes and their inhibition in cancer cell invasiveness
Martinková, Eliška ; Peltanová, Barbora (advisor) ; Raudenská, Martina (referee)
Glycolysis, an essential metabolic pathway, serves to obtain energy from glucose. All ten enzymes, which are part of the glycolytic pathway, may be involved in processes that influence migration and the ability of tumor cells to invade surrounding tissues, which is closely related to the formation of metastases. Since the majority of patients with diagnosed solid tumors die because of complications associated with primary tumor metastases, studying this phenomenon is of great interest. The purpose of this thesis is to summarize the findings on the relationship between glycolytic enzymes and tumor cell invasion. Diverse roles of enzymes related to invasion, migration and metastases are described herein, ranging from influencing angiogenesis, cytoskeleton formation and mRNA and protein stabilization to affecting various signal cascades. Room is devoted not only to the relevant mechanisms at the molecular level but also to the results of research focused on therapy to date. The thesis also provides an overview of selected inhibitors of glycolytic enzymes that affect tumor cells invasion. Key words: invasion, migration, metastasis, glycolytic enzymes, inhibition, EMT, Warburg effect
Effect of food supplement mixtures on selected biotransformation enzymes
Kurshakova, Evgeniia ; Dračínská, Helena (advisor) ; Koblihová, Jitka (referee)
Dietary supplements are globally used products designed to complement nutrition with additional nutrients. They contain a wide range of biologically active compounds: amino acids, vitamins, minerals, herbal extracts, etc. Due to the popularity and excessive consumption of food supplements, there is a growing need to research their potential interactions and impact on human health. Certain dietary supplements are metabolized by enzymes from the cytochrome P450 group, which play a key role in the biotransformation of exogenous substrates. Some biologically active compounds may also affect their activity. The presented thesis was focused on studying the influence of several popular components of dietary supplements on cytochromes P450 3A4 and 1A1 expressed in the gastrointestinal tract. The influence of metal ions Zn2+ and Mg2+ , ascorbate from the vitamin group, and curcumin from the polyphenol group was examined. A strong inhibitory effect of curcumin on the activity of both investigated isoforms was confirmed. The reaction of 6β-hydroxylation of testosterone catalyzed by CYP3A4 was significantly suppressed by the addition of curcumin, with the determined IC50 value being 4,7 M. A significant decrease in the rate of resorufin O-deethylation by rat and human CYP1A1 isoforms was also observed (IC50 =...
Analysis of Thick Film Amperometrical Sensors Signal and Its Usage for Measurement and Characterization of Enzymes
Ondruch, Vít ; Kizek, René (referee) ; Masojídek,, Jiří (referee) ; Vrba, Radimír (advisor)
V práci je popsán princip synchronní detekce (SD), který byl uplatněn při měření s biosenzory. Metoda SD umožňuje dosažení výrazně lepšího poměru signálu k šumu, vyššího limitu detekce a celkové zlepšení robustnosti měření. Uplatnění SD při měření s biosenzory umožní zlepšit analýzu jeho odezvy a umožní odstranění nežádoucích interferencí nebo šumů, které mohou být způsobeny například mícháním roztoku, elektromagnetickými vlivy nebo parazitními proudy. SD také umožňuje rozložit získaný signál na odezvu stimulace a na dlouhodobý signál jiného procesu, a dále také identifikovat jevy druhého řádu. Pro identifikaci stimulačního signálu ve výstupním signálu měření byl na základě lineárního statistického modelu vyvinut specializovaný software. SD byla ověřena na modelovém případu výstupního signálu biosenzoru s aplikovaným komplexem fotosystému II (PSII) a jeho odezvě na stimulaci světlem. Odezva PSII se řídí kinetikou prvního řádu a může být také ovlivněna inhibitory. Kinetické konstanty vazby herbicidu na PSII závisí lineárně na koncentraci herbicidu. To umožňuje jejich měření také při nízkých koncentracích herbicidu.
Inhibition of Hazardous Compounds in Alumino-Silicate Systems
Koplík, Jan ; Škvára, František (referee) ; Rovnaníková, Pavla (referee) ; Havlica, Jaromír (advisor)
The ability of alumino-silicate systems to immobilize hazardous compounds has been investigated since 1990s. The aim of this work is to develope alumino-silicate system (matrix) based on industrial waste products with ability to immobilize hazardous compounds (heavy metals). This ability of the matrix was confirmed by leaching tests based on the law 294/2005 Sb. Concentration of heavy metals in leachates was determined by ICP-MS method. Alumino-silicate system prepared in this work consists of high-temperature fly ash and blast furnace slag activated by mixture of alkaline activators (hydroxide and water glass). Matrixes were characterized by suitable analytic methods (XRD, SEM, FT-IR, DTA-TGA-EGA). The same analytic methods were used to describe the mechanism of immobilization of selected elements (Ba, Cu, Pb) in prepared systems.
Biofilm formation in probiotic cultures and its application in pharmacy
Ryšávka, Petr ; Obruča, Stanislav (referee) ; Vorlová, Lenka (referee) ; Márová, Ivana (advisor)
The work was comprehensively focused on the development of adhesive forms of probiotics in the form of a biofilm on combined carriers with a prebiotic component. The second part dealed with the influence of food on the multiplication and survival of selected types of probiotic bacteria. Subsequently, the effect of individualized probiotic supplements on changes in the human intestinal microbiome was monitored. Suitable adherent probiotic strains for biofilm formation were selected and tested. Methods have been introduced and different variants of carriers for culturing and binding bacteria have been tested. In vitro experiments verified the stability of biofilm stucture and its resistance to low pH, bile and antibiotics in comparison with the planktonic cell form. The antimicrobial effect of probiotic strains in the form of a biofilm was studied. The cultivation of the multispecies biofilm on the combined carrier was optimized and the stability of the biofilm and the final viability of probiotic bacteria were confirmed. Furthermore, the influence of various foods and beverages on the viability of probiotic bacteria was evaluated with emphasis on the simulation of passage through the gastrointestinal tract. Both models, solutions with standardised concentrations of alcohol, sugar, salts, proteins or different pH and different types of real foods and beverages were tested. The effect of food and beverages was tested on monocultures of Lactobacillus acidophilus, Bifidobacterium breve and on probiotic capsules containing a mixed culture of probiotic microorganisms. The survival of probiotics in various food matrices in the simulated gastrointestinal tract was quantitatively different. We managed to define foods suitable for supporting the multiplication of probiotic bacteria. A separate part of the work was focused on the targeted modulation of the intestinal microbiome by individualized probiotics that were prepared on the basis of molecular biological analyzes of the intestinal microbiome aimed at detecting the percentage of lactobacilli, bifidobacteria and phylum Firmicutes and Bacteroidetes. Personalized probiotic supplementation confirmed the positive effect of this approach on microbiome changes, especially on the increase of the content of lactobacilli, bifidobacteria and the overall diversity of the microbiome.
Leachability of Ba and Cr from alkali-activated matrices
Cába, Vladislav ; Hajzler, Jan (referee) ; Koplík, Jan (advisor)
The aim of this work is to determine the usability of alkaline activated matrices made from ashes to inhibition of barium and chrome. Ashes – fly ashes and ashes from fluidized bed combustion – were compared with cement used for inhibition. By using inductively coupled plasma atomic emmission spectrometer were determined concentrations of barium and chrome in leachates based on norm ČSN EN – 12457-4. In addition, images were taken on the scanning electron microscope and crystallographic spectra from X-ray crystalography were obtained to determine structure. The results show that ashes from fluidized bed combustion are suitable for inhibition of both barium and chrome, whereas fly ashes can not sustain these elements with such success.
Fixation of the lead in alkali activated materials based on different types of ashes
Cába, Vladislav ; Kalina, Lukáš (referee) ; Koplík, Jan (advisor)
The aim of this work was to develop an alkali activated matrix based mainly on fly ash, to determine the ability to fix lead in these matrices, the impact of added lead on mechanical properties and to reveal the way of lead fixation in these matrices. The matrices consisted mainly of fly ash (four from fluidized bed combustion, one pulverized coal combustion) with an admixture of blast furnace slag and sodium silicate as an activator. Lechates were prepared on the basis of the ČSN EN - 12457-4 standard, lead concentrations in them were measured using an atomic emission spectrometer with inductively coupled plasma. The strengths of the samples were measured after 28 days. Images, element maps and element spectra were taken to determine the structure using a scanning electron microscope with an electron dispersion spectrometer, the samples were analyzed on an infrared spectrometer with a Furier transform, X-ray diffraction analysis and electron spectroscopy for chemical analysis were also used. The individual measurements showed that lead is accumulated in the form of hydroxide. The impact of lead doping on strength of the matrix was different for individual samples. Matrices from both types of fly ash released minimal amounts of lead into leachates, so it is possible to use them to fixate lead.
Inhibition of hydrogen evolution in aluminum-phosphate refractory binders
Bednárek, Jan ; Kalina, Lukáš (referee) ; Šoukal, František (advisor)
The thesis deals with the possibilities of inhibition of the reaction of aluminium-phosphate binders with wear iron, which is contained in bauxite. This material is mixed with phosphate binders to form refractories. The hydrogen is produced by this reaction causing the mixture foaming. The amount of evaluated hydrogen was observed by the measuring by the Jank’s calcimeter. Also the shape of oxidation-reduction potential of the binders was measured before and after mixing with aggregate, using potentiometer. The influence of the addition of various cations on the hydrogen evolution and on the oxidation-reduction potential was observed. The effectiveness of the inhibitors was studied also visually by forming test elements.

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