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Effect of dysbiosis on proportion of particular neutrophil subsets and their functional capacities
Sklenářová, Lydie ; Hrdý, Jiří (advisor) ; Dobeš, Jan (referee)
The gut microbiota is crucial for maintaining physiological balance and influences metabolic processes, immune responses, and intestinal barrier function. Dysbiosis, or the imbalance of microbial composition, is associated with a range of health complications, including chronic inflammatory conditions such as non-specific intestinal inflammations. Inflammatory processes associated with dysbiosis and changes in microbial metabolites can directly affect the activation of neutrophils, impacting the pathogenesis of various diseases. Probiotics, defined as live microorganisms which, when administered in adequate amounts, confer a health benefit on the host, offer the potential for positive modulation of these inflammatory conditions The aim of this thesis was to explore how experimentally induced intestinal dysbiosis affects the heterogeneity of neutrophils in the bone marrow. Dysbiosis was induced by administering antibiotics to mice, which were subsequently treated with the probiotic strain Escherichia coli O83:K24:H31 (EcO83). Neutrophil phenotypes were assessed using flow cytometry based on the expression of surface markers CD11b, Ly6G, CD62L, and CXCR2. Meanwhile, gene expression related to their antimicrobial functions and the inflammatory environment was analyzed by quantitative PCR. The results...
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Evolution of nuclear DNA content variation in the genus Mallomonas and its ecophysiological consequences
Čížková, Natálie ; Čertnerová, Dora (advisor) ; Trávníček, Pavel (referee)
The variability of genome size among eukaryotes and its consequences remains largely unknown. This is particularly true for unicellular eukaryotic organisms, also known as protists, whose nuclear DNA content is still largely unexplored. Across plants or animal studies, it has been repeatedly demonstrated that genome size is closely associated with cell size and may also be related to other eco-physiological parameters, such as growth rate, metabolic rate, or life strategy. In protists, the cell represents their entire body, allowing for the direct assessment of the impact of genome size on organismal phenotypic traits. In this thesis, with the use of flow cytometry, the absolute amount of nuclear DNA was estimated for 165 strains of the genus Mallomonas (Chrysophyceae) belonging to 64 species, revealing diversity in nuclear DNA content for nearly 1/4 of the globally recognized diversity of this genus. Based on the obtained data, up to 100-fold variability in nuclear DNA content was found across Mallomonas species (0.12 pg - 11.4 pg). Detected intraspecific variability in nuclear DNA content suggests the influence of various evolutionary mechanisms, for example multiple-fold difference in DNA content (even within closely related species) suggest frequent polyploidization in the genus Mallomonas....
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Investigation of the role of the KEAP1-NRF2 antioxidant pathway in the therapy of secondary acute myeloid leukaemia
Myšáková, Michaela ; Pimková, Kristýna (advisor) ; Suttnar, Jiří (referee)
The development of therapy resistance is a long-standing problem in treating cancer, particularly in the treatment of myelodysplastic syndrome (MDS) and acute myeloid leukaemia (AML), where the hypomethylating agent 5-azacytidine (AZA) is the first choice of treatment. To enhance therapeutic efficacy, AZA is often combined with other agents such as pevonedistat (Pevo), a NEDDylation inhibitor targeting the ubiquitin-proteasome system. While initial results showed a synergistic effect of the AZA and Pevo combination in treating MDS and AML, dual resistance has been described, underlining the importance of understanding the mechanisms behind the resistance development. Our previous data demonstrated an essential role of redox homeostasis and antioxidant system represented by Nuclear factor erythroid 2-related factor 2 (NRF2) in AZA resistance. The Kelch-like ECH-associated protein 1 (KEAP1)-NRF2 pathway is the master regulator of antioxidative defence in cells crucial for maintaining redox balance. However, hyperactivation of NRF2 has been implicated in therapy resistance and cancer progression. We hypothesised that NRF2 is crucial in MDS/AML therapy resistance, particularly in resistance to combined AZA and Pevo therapy. We worked with cells sensitive and resistant to AZA and Pevo and monitored...
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Reconstitution of lymphocytes after allogeneic hematopoietic stem cells transplantation
Zmij, Patrik ; Souček, Ondřej (advisor) ; Řezáčová, Vladimíra (referee)
Charles University, Faculty of Pharmacy in Hradec Králové Department of Biological and Medical Sciences Author: Bc. Patrik Zmij Supervisor: RNDr. Ondřej Souček, Ph.D. Title of diploma thesis: Lymphocyte reconstitution after allogeneic hematopoietic stem cell transplantation Allogeneic hematopoietic stem cell transplantation is the most effective treatment option for patients with hematologic malignancies, including acute myeloid leukemia, myelodysplastic syndrome, or the rarer myelosarcoma. After a successful transplantation, the immune system cells are regenerated, and this master's thesis focuses on one aspect of that process: lymphocyte reconstitution. The experimental part of the study involved patients who underwent allogeneic transplantation of blood- forming cells based on their unfavorable diagnosis. These patients were then monitored for one year at the Institute of Clinical Immunology and Allergology at the Faculty Hospital in Hradec Králové. Observations were conducted at three months and continued until the end of the first year, using flow cytometry as the method of assessment. By analyzing diverse surface markers on selected immune cells, it was possible to track patients with hematologic malignancies and observe the subsequent course of lymphocyte reconstitution after allogeneic...
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Determination of vibality of rhizobacterial cultures
Svobodová, Lucie ; Slaninová, Eva (referee) ; Obruča, Stanislav (advisor)
This thesis focuses on the study of viability of plant growth promoting rhizobacteria (PGPR). Viability was determined in three strains of Azotobacter vinelandii, namely CCM 289, DSM 87 and DSM 720, using flow cytometry with fluorescent probe PI, SYTOXTM Blue and DAPI after 120 and 72 hours of cultivation. Optimization of the appropriate fluorescent probe for the strain was performed, with the PI probe for strain CCM 289 being the most suitable. PI and SYTOXTM Blue probes can be used for strains DSM 87 and DSM 720. For the following experiments, strain DSM 87 was selected and subjected to the influence of different crosslinking reagents. Using a flow cytometer and staining with a fluorescent PI probe, the viability was verified after application of calcium chloride, barium, copper, ferric, aluminium and calcium sulphate solutions of 2, 0.2 and 0.02 wt. % to the culture. Calcium chloride, barium and calcium sulfate solutions had no significant effect on cell viability. On the other hand, when ferric chloride was used, a trend was observed where dead cells decreased with decreasing concentration of the solutions. This effect was also achieved with aluminium and copper chloride, but the use of the most concentrated solution resulted in the inactivation of a greater number of cells than in the previous case, whereas aluminium chloride resulted in the loss of viability of most of the cells present. Viability was also verified for cells released from the prepared gels. For the experiments, solutions of the aforementioned crosslinking agents were chosen at a concentration of 2 wt.%, and the culture was subjected to gelation under the experimentally determined conditions. A portion of the gels was subsequently left in phosphate buffer to allow for the re-release of cells. To facilitate this release, the enzyme alginase was added to break down the alginate. It was found that a concentration of 2 wt % of the selected crosslinking agents did not affect cell viability, i.e., the cells released from the gel appeared to be viable.
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Involvement of polyhydroxyalkanoates in stress response of bacteria during late stationary phase
Šuráňová, Zuzana ; Sedláček, Petr (referee) ; Obruča, Stanislav (advisor)
The aim of this work was to study the involvement of polyhydroxyalkanoates into stress response of bacteria in the late stationary phase. Bacteria Cupriavidus necator H16 (able to produce PHA) and bacteria Cupriavidus necator H16/PHB-4 (unable to produce PHA) were used for the experiment. In the theoretical part, the polyhydroxyalkanoates and a stress response of bacteria were reviewed. In the experimental part of the work, the involvement of polyhydroxyalkanoates into stress response of bacteria in the late stationary phase against selected stress factors was studied. A resistence against various stress conditions of bacteria was studied. During long term cultivations a culture viability as well as PHA distribution among bacterial populations were assessed by using flow cytometry and the PHA content in biomass was analyzed by gas chromatography with FID detector.. Based on the results obtained in this work, it was found that the PHA acumulating bacteria Cupriavidus necator H16 is capable to survive carbon substrate limitations better than the bacteria Cupriavidus necator H16/PHB. Further, Cupriavidus necator H16 also revealed higher resistence against various stress factors such as ethanol treatment and freezing.
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Influence of PHA accumulation on resistance of bacteria against selected antibacterial drugs
Hrabalová, Vendula ; Kučera, Dan (referee) ; Obruča, Stanislav (advisor)
The aim of this bachelor thesis was to study the effect of bactericidal drugs on bacteria from the genus C. necator H16 and its mutant genus PHB-4. The genus H16 shows ability to accumulate polyhydroxyalkanoates (PHA) in the form of granules while the genus PHB-4 lacks to show this ability. The theoretical part of the bachelor thesis is focused on the effect of antibiotics on bacteria in general and the determination of susceptibility of bacteria to antimicrobial substances. The effect of three specific antibiotics (nisine, streptomycin and penicillin) on both bacterial strains was tested in the experimental part. The viability of bacteria was determined by the spread plate method and flow cytometry. Agar diffusion test and broth microdilution test were used to test the susceptibility of bacteria. It was concluded that the accumulation of PHA decreases the tolerance of bacteria to antimicrobial substances because the genus C. necator H16 is more susceptible to streptomycin and penicillin then the strain C. necator PHB-4.
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Use of some encapsulation techniques to controlled release of active substances in food and cosmetics products.
Skoumalová, Petra ; Rittich, Bohuslav (referee) ; Kráčmar, Stanislav (referee) ; Márová, Ivana (advisor)
The presented doctoral thesis is focused on preparation, characterization and application of organic micro- and nanoparticles as transport systems for active components and some their complex natural sources. Active component were packed into liposomes and polysaccharide particles. As active components were used caffeine, some drugs – clotrimazole and ibuprofen, further antioxidants and vitamins. Antimicrobial herbs and spices extract, antimicrobial peptides lysozyme, nisin and other antimicrobial ingredients were encapsulated too. Encapsulation of selected hydrolytic enzymes was tested, too. Particles were also used for encapsulation of probiotic strains Bifidobacterium breve and Lactobacillus acidophilus and prebiotic components. These prebiotics were co-encapsulated into capsules with probiotic cells. Natural extracts were encapsulated e.g. extracts of guarana, ginseng, goji, green barley, propolis, black, green and white tea, coffee, fruit and vegetable extracts. The efficiency of encapsulation was determined by HPLC/PDA and by spectrophotometry. Long-term stability of particles and amount of released component in model/real foods, in model cosmetic conditions and in a model physiological environment were monitored too. Size of prepared liposomes and polysaccharide particles was determined by dynamic light scattering and by light microscopy and electron microscopy, respectively. Stability of the particles was measured using a zeta potential. Also, analytical centrifugation was used to measurement of sedimentation velocity and stability of the prepared particles. The antimicrobial activity were tested using two Gram-positive (Bacillus subtilis, Micrococcus luteus), two Gram-negative (Escherichia coli, Serratia marcescens) bacteria and one fungal strains (Candida glabrata). For determining the antimicrobial properties of active component and prepared particles two the most widely used methods were used - agar diffusion method and broth dilution method. The viability of probiotic strains were performed using flow cytometry and fluorescence microscopy. Encapsulation of active component was successful in all types of particles. Liposome showed a very good long-term stability mainly in water conditions with neutral pH and polysaccharide particles were stable in acidic conditions. Prepared particles showed a very good stability in model stomach environment, while in model intestines environments particles were disintegrated and active component were released. Prepared particles with encapsulated caffeine as well as other tested antioxidants and vitamins could be used to modern types of energy drinks, food supplements and also for some cosmetics applications. Encapsulated antimicrobial components could be used for food application as well as for cosmetics and pharmaceutical application like antimicrobial wound formulation. Encapsulated enzymes can be used for controlled release of proteases in wound healing, as delivery systems in digestive tract and as a part of pharmaceutical preparative and food supplements for enzyme therapy. The study revealed that encapsulation of probiotics and also co-encapsulation of probiotics with prebiotics exhibited longer stability of particles and survival bacterial cells. So, prepared particles are suitable for use to food product with beneficial effects on the human body.
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Preparation and stability of beer enriched by probiotics
Kočnar, Michal ; Mikulíková, Renata (referee) ; Márová, Ivana (advisor)
The presented diploma thesis is focused on the preparation and the monitoring of the biological stability of beer enriched with probiotics. Probiotic bacterial strains of Lactobacillus acidophilus, Bifidobacterium breve and Bifidobacterium bifidum were used in this study. The theoretical part is divided into two sections. In the first section, probiotics are generally characterized, and their role within a gut microbiota is described. Next, the microbiology of particular probiotic microorganisms including the genera of Lactobacillus and Bifidobacterium is described. Then, some factors influencing the viability and the growth of probiotics are stated. In this section, biological effects of probiotics on the human organism and their potential clinical applications are described. The second section of the theoretical part deals with the technology of brewing, the chemical composition of beer and particular beer styles. In the experimental part, the methods of probiotic bacterial cell concentration and viability determination were optimized. Several techniques for determination of these parameters were selected, particularly the cultivation method, flow cytometry and the spectrophotometric measurement of turbidity. Then, the growth curves of the probiotic strains were measured in MRS medium. Probiotic bacteria were cultivated in model beer samples, i.e. in MRS media with several different concentrations of ethanol. It is possible to say that ethanol did not have significant effect on probiotics growth. Next, experimental cultivations of individual probiotic bacteria and their mixtures in nine real beer samples were conducted. No increase of viable cells concentrations was detected in the samples. On the contrary, a decrease of the concentrations was observed, mainly in the samples with individual bacterial strains. However, certain values of viable cells concentrations were determined at the end of the cultivations in all cases. A pale, top-fermented beer was brewed and supplemented with probiotics, and the concentrations of viable probiotic cells were monitored during 37 days of fermentation. A decrease of concentrations by two orders of magnitude of CFU/ml was observed in almost all samples. Yet, viable cells of probiotic bacteria were detected in all samples of beer at the end of the fermentation. Maximal concentration of viable probiotic cells in the brewed beer was determined with the cultivation method at (3,80 ± 0,14)10^5 CFU/ml. Chosen samples were analyzed with HPLC-RI method that quantified the common beer concentrations of ethanol in all chosen samples, lactic acid was not detected. Sensory analysis was conducted as well. Based on the results of the experimental part and the bibliography, an optimal technology of the preparation of beer enriched with probiotics is discussed in this study.
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Application of flow cytometry for multiplex analyses in clinical biochemistry
Babušíková, Lucie ; Tremlová,, Bohuslava (referee) ; Beňovská,, Miroslava (advisor)
This thesis discusses the technique of flow cytometry for multiplex analysis and its use in conjunction with imunochemical methods. As part of this work was carried out clinical studies dealing with secondary prevention of myocardial infarction and atherosclerosis in 186 pacientů. In this time represents myocardial infarction worldwide civilizational problem. A number of possible parameters for monitoring atherosclerosis in the world is still an unresolved issue. In the practical part of this work we performed an analysis using Luminex xMAP technology for new parameters (adiponectin, resistin, osteopontin) to predict atherosclerotic disease associated with myocardial infarcion. Also we wanted to see how these parameters are changed in patients after increasing the dose of therapeutic drugs.
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