|
|
Biochemical Aspects of Artwork Restoring
Boledovičová, Petra ; Hudeček, Jiří (advisor) ; Kubíčková, Božena (referee)
The following bachelor thesis is focussed on findings on the field of art restoring in connection with its biochemical aspects. In itroduction is resumed brief history of art restoring and generally defined terms of preservation, restoring, art and paint. For better understanding basic paint techniques (aquarelle, gouache, tempera and oil painting), strata sequence and instruments and materials commonly used for art work are mentioned. Most frequently used organic and inorganic pigments are briefly mentioned, however this thesis is mainly focussed on applied organic compounds - lipids, proteins, polysacharides and terpenoids - its composition, characteristics, usagea nd possible interactions. The following thesis is written in czech. Key words: restoring, art work, paint, organic binders, lipids, proteins, polysacharides, terpenoids
|
|
|
NADP-dehydrogenases of medicinal plants.
Bartošová, Martina ; Hýsková, Veronika (advisor) ; Kubíčková, Božena (referee)
Medicinal plants usually contain metabolites formed by secondary biosynthetic pathways for example phenylpropanoid and shikimate pathway, which depend on NAPDH availability. In this work total content of phenolic compounds and flavonoids was determined in 10 medicinal plants common for Czech Republic. Activity of enzymes providing NADPH was determined as well. These enzymes were glucose-6-phosphate dehydrogenase (G6PDH, EC 1.1.1.49), NADP-isocitrate dehydrogenase (NADP-ICDH, EC 1.1.1.42), NADP-malic enzyme (oxalacetate decarboxylating) (NADP-ME, EC 1.1.1.40). The activity of shikimate dehydrogenase (SDH, EC 1.1.1.25), the main enzyme of shikimate pathway, was also determined. Extraction methods were optimized for each assessment. Applicable source for NADP-dependent enzymes are black radish (Raphanus sativus L. var. niger), garlic (Allium sativum L.) and mint (Mentha piperita L). The highest content of phenolic compounds and flavonoids was determined in sage (Salvia officinalis), lemon balm (Melissa officinalis L.) and Mentha citrata. Extraction with methanol was more effective than extraction with hot water. More extraction methods and studies are necessary for characterization of individual compounds and principals on which they work. Key words: medicinal plants, NADP-dependent enzymes, phenolic...
|
|
|
Role of benzo[a]pyrene in cancer development
Vaňátková, Petra ; Moserová, Michaela (advisor) ; Kubíčková, Božena (referee)
4 ABSTRACT Cancer is nowadays one of the most serious diseases. Tumor development is a multistage process in which the effect of internal and external factors lead to failure of regulatory and defense mechanisms of the organism and to the accumulation of mutations which are generated by these organisms. Chemical carcinogens and also biological and physical factors can be regarded as the main external factors. Polycyclic aromatic hydrocarbons are large group of chemical carcinogens. One of them, benzo[a]pyren is the most studied polycyclic aromatic hydrocarbon. Carcinogenic, mutagenic and teratogenic effects of benzo[a]pyrene had been shown on laboratory animals. Benzo[a]pyrene is considered as the main carcinogen in tobacco smoke and is connected with lung cancer development among smokers. Benzo[a]pyrene is metabolized in activation or detoxication pathways by enzymes of mixed function monooxygenase systeme of cytochromes P450. The most important enzymes involved in the activation of these compounds are CYP1A1 and CYP1B1 with cooperation of epoxide hydrolase. The reactive species generated in its activation pathway are able to form covalent adducts with DNA. The most important carcinogenic product of benzo[a]pyrene is benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide, which can caused irreversible ganges in...
|
|
|
Enzymes metabolizing drugs
Škodová, Petra ; Stiborová, Marie (advisor) ; Kubíčková, Božena (referee)
Mixed function oxidase system (MFO) is one of the most effective systems of enzymes of the first phase of biotransformation of xenobiotics. Cytochromes P450 seem to be the most important part of the MFO system, which also contains other components such as NADPH:CYP reductase and membrane lipids. Cytochromes P450 function as a terminal oxidase of the mixed function oxidase (MFO) system. Many xenobiotics, including drugs, are the substrates of these enzymes. Endogenous substances can serve as the substrates of these enzymes as well. Peroxidases are a group of enzymes which are able to metabolize drugs. The function of cytochromes P450 can be substituted by peroxidases. Both groups of enzymes are able to potentiate the effect of the drugs by activating them or they form deactivated metabolites, which are excreted from the organism. The action of cytochromes P450 and peroxidases is shown on the metabolism of the drug ellipticine. Ellipticine has anticancer effects. The advantage of this drug is its low number of side-effects. The oxidation of ellipticine by cytochromes P450 and peroxidases leads to its metabolic activation or detoxification. Carbenium ions are generated by spontaneous cleavage of two active metabolites, 12-hydroxyellipticine and 13-hydroxyellipticine. Carbenium ions then form adducts...
|
|
|
The development of a model system for studying chloride ion transport in the epithelial cells of patients with cystic fibrosis
Pecková, Kateřina ; Bořek Dohalská, Lucie (advisor) ; Kubíčková, Božena (referee)
Cystic fibrosis is caused by a genetic defect in the CFTR protein, whose main function is chloride transport across epithelial cells. The measurement of CFTR ability to transport chloride is considered a good, and perhaps, the only practical method to assess its activity. In this thesis, the transport of chloride ions across the CFTR channel was studied using airway epithelial cell lines of healthy patients (NuLi-1) and patients with cystic fibrosis (CuFi-1). A fluorescent method using a fluorescent chloride-sensitive probe N-(ethoxycarbonylmethyl)-6-methoxyquinolinium (MQAE) was chosen and optimized. This compound is providing fluorescence in the blue part of the spectrum and has the greatest sensitivity to chloride ions. In the development of an optimal method two approaches of chloride transport measurement were used. In the first experiment the secretion of the chloride ions to the buffer containing MQAE was measured. In the second one the dye had to be loaded into cells before performing experiment. Then, the MQAE fluorescence quenched by intracellular chloride was monitored by a change in the fluorescence intensity of the probe. The second method was considered as a usefull and more reproducible to study chloride transport across cell membranes. Moreover, the influence of the CFTR modulator...
|
|
|
Modulation of activities and expression of enzymes metabolizing ellipticine by histone deacetylase inhibitor trichostatin A
Kopejtková, Barbora ; Stiborová, Marie (advisor) ; Kubíčková, Božena (referee)
Histone deacetylase inhibitor trichostatin A (TSA) increases cytotoxicity of antineoplastic agent ellipticine to human neuroblastoma cells. Its mechanism of action has not yet been explained. One of the possible mode of action is conformational change in chromatin, which leads to changes in DNA that is more accessible to covalent modification and intercalation. The aim of this work is to study another mode of action, which can explain this phenomenon. The question is, if TSA can increase cytotoxicity of ellipticine to human neuroblastoma cells by modulation of activities and expression of cytochromes P450 and peroxidases. These enzymes are responsible for cytotoxicity of ellipticine to human neuroblastoma cells. TSA has no effect on oxidation of ellipticine mediated by cytochromes P450 leading to metabolites responsible for formation of ellipticine-DNA adducts and detoxication metabolites. TSA increases formation of ellipticine dimer, which is a detoxication metabolite, forming during its oxidation by peroxidases. TSA has no effect on activities of CYP1A1, CYP1A2, CYP3A, which significantly participate in oxidation of ellipticine. TSA modulates expression of enzymes oxidizing ellipticin in human neuroblastoma cells. TSA in the presence of ellipticine increases expression of CYP1A1 a CYP3A4 in...
|
|
|
Connection between abiotic stress and NADP-dependent enzymes in plants
Plisková, Veronika ; Hýsková, Veronika (advisor) ; Kubíčková, Božena (referee)
Salt stress in plants is accompanied with decreased growth caused by lowered leaf water potential, closed stomata and thus reduced photosynthesis producing NADPH. However, NADPH is indispensable coenzyme for biosynthetic processes (e.g. biosynthesis of osmotically active compounds decreasing influence of stress) and for antioxidant system. In this study it was examined, whether NADP-dependent enzymes: glucose-6- phosphate dehydrogenase (G6PDH), NADP-isocitrate dehydrogenase (NADP-ICDH), NADP-malic enzyme (NADP-ME) and NADP-shikimate dehydrogenase (SDH), producing NADPH are involved in plant defence response against 100 mM NaCl. Three different model plants were used: Pisum sativa L., Phaseolus vulgaris L. and Cucumis sativa L. While in leaves of pea and bean plants salt stress caused rather decreased activities of particular NADP-dependent enzymes (especially of G6PDH and NADP-ICDH), in leaves of cucumber 9th and 11th day of stress condition were found increased activities of all studied enzymes. Simultaneously the Na+ content in salt-stressed plants was analysed by atomic emission spectrometry.
|
|
|
Interaction of selected flavonoids with cytochromes P450 2B
Boštíková, Zdislava ; Hodek, Petr (advisor) ; Kubíčková, Božena (referee)
In recent years, there has been increased emphasis on healthy lifestyle, which includes, among others, consumption of natural nutrients in a form of various food supplements. These compounds, usually of a flavonoid character, show different chemopreventive effects such as anti-oxidant or anti-carcinogenic. The excessive consumption of these compounds can also have a negative impact on human health. Flavonoids may for instance influence the content of biotransformation enzymes, cytochromes P450, in the cells and thus influence the metabolism of foreign compounds. Such an influence might, as a result, lead to a development of carcinogenesis or inefficacy of certain medications. The main focus of this bachelor thesis is to study capabilities of two flavonoid compounds (myricetin and dihydromyricetin) to induce and inhibit cytochromes P450 of 2B family. By the Western blot method it was found that neither of the investigated flavonoids increased expression of CYP2B1/2 in livers, myricetin, or in any part of small intestine. In the case of dihydromyricetin there was noticed an induction of cytochromes P450 2B in the middle part of small intestine. The inhibitory potency of flavonoids was examined in vitro as an inhibition of 7-pentoxyresorufin O-depentylation catalyzed by CYP2B. Values of IC50 8,8μM and...
|
|
|
Isolation of bacterial flagellin as an immunogen for the preparation of antibodies for cystic fibrosis patients
Supová, Veronika ; Hodek, Petr (advisor) ; Kubíčková, Božena (referee)
Cystic fibrosis (CF) is an autosomal recessive disease caused by CFTR gene mutation. The consequence of this mutation is an improper function of the chloride channel consisting of CFTR protein. Due to this abnormality, the transport of chloride ions is either reduced or inhibited completely, which leads to a mucus secretion. Mucus is mostly created in the lungs and it is the ideal environment for pathogenic bacteria like Pseudomonas aeruginosa (PA). Pseudomonas aeruginosa is an aerobic, gram-negative conditioned pathogen occurring in patients with weakened immunity such as patients with CF, who are often hospitalized. PA has one polar flagellum which contains filament composed of a protein called flagellin. The flagellum is one of the most important virulence factors of PA bacteria. This thesis focused on the isolation of flagellin from Pseudomonas aeruginosa flagella. The isolated flagellin will serve as an antigen for the preparation of prophylactic antibodies for CF patients. The isolation of flagellin was carried out by four methods using combinations of precipitation and centrifugation. The published methods were optimized to achieve the isolation of flagellin. Final samples and intermediates were analyzed by SDS-electrophoresis on polyacrylamide gel and the presence of flagellin was verified...
|
|
|
Use of chicken antibodies against PAIIL lectin for prevention of Pseudomonas aeruginosa infections in patients with cystic fibrosis
Kubíčková, Božena ; Hodek, Petr (advisor) ; Anzenbacherová, Eva (referee) ; Eckschlager, Tomáš (referee)
Cystic fibrosis (CF) is one of the relatively common inherited diseases caused by a mutation in the gene encoding for CFTR protein, which forms a chloride channel that significantly affects ion homeostasis and the associated fluid management of the cell. This disease mainly affects the respiratory and digestive systems, being the most life-threatening in the respiratory tract. Patients with CF suffer from frequent and recurrent respiratory infections that lead to the development of chronic inflammation and gradual destruction of lung tissue. These lung infections, which are caused mostly by the opportunistic pathogen Pseudomonas aeruginosa, are the most common cause of morbidity and mortality in these patients. At present, antibiotics are used in the treatment of Pseudomonas aeruginosa infections, but new methods of antibacterial therapy need to be found to overcome the development of resistance. In addition to active immunization of CF patients against Pseudomonas aeruginosa, their passive immunization with specific chicken antibodies directed against this pathogen offers promising possibilities. This dissertation thesis is aimed to verify the prophylactic potential of hen IgY antibodies against the virulence factor Pseudomonas aeruginosa - lectin PAIIL, and to further develop an experimental...
|
guest ::
RSS feed.