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Hyaluronan-albumin complexes behavior at physiological conditions.
Šuleková, Nikola ; Kratochvílová, Romana (referee) ; Chytil, Martin (advisor)
This thesis discusses the interactions of low molecular weight and high molecular weight hyaluronic acid (HA) with bovine serum albumin (BSA) in physiological environment. It is based on previous work dealing with HA and amphiphilic substances which are currently widely studied for its potential applications in medicine. Solutions of HA with fixed concentration and albumin of concentration in the range of 0,25 – 20 g/l were prepared at room temperature and at 37°C and examined by rheometry and turbidimetry. It was observed that the maximum absorbance increases with increasing concentration of BSA and does not show variations depending on the temperature of preparation. On the other hand, the turbidity occurs in significant differences between the samples prepared at ambient temperature and at 37°C. Overall, the turbidity increases with the concentration of BSA. Rasing the temperature caused the increase in viscosity of the samples, which was further varied with the concentration of BSA. Mixed solutions of high molecular weight HA and BSA showed the highest turbidity, maximum absorbance and viscosity, while the solutions of BSA showed the lowest values. The results indicate formation of complexes, of which properties are dependent on BSA concentration, the molecular weight of HA, and the temperature of preparation.
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Preparation and Characterization of Mixed Hydrogels Based on the System Hyaluronan-Albumin
Hájovská, Pavla ; Kráčalík, Milan (referee) ; Kalina, Michal (advisor)
This diploma thesis deals with preparation and subsequent characterization of albumin (BSA) and mixed hyaluronan-albumin (HA+BSA) hydrogels. The experimental characterization was based on the rheological measurements of the influence of ionic strength, pH and molar mass of HA on the gelation process and the properties of formed gels, as well as the time stability of these properties. Following object of the study was swelling of hydrogels in water and buffers with different pH value. Characterization was extended by thermal analysis, morphology description using scanning electron microscopy (SEM) and study of transport properties of hydrogels for selected model substance. Due to increasing ionic strength, the gel point was shifted towards higher temperature values and the resulting gels exhibited higher values of complex moduli. In case when pH was lower than isoelectric point of BSA, attractive electrostatic interactions between albumin and hyaluronan took place and the faster gelation occurred, compared to the case when pH was higher than isoelectric point of BSA. On the contrary, values of complex moduli increased with increasing pH. The gel samples prepared in the presence of low molecular weight HA reached higher values of complex moduli, compared to samples with the high molecular weight HA. Rheological properties of BSA gels were stable over time, whereas the mixed HA+BSA were characterized by significant decrease of complex moduli during the first three days of storage. Due to heating up to 100 °C, more than 80 % of the weight of studied samples was lost, as a result of water evaporation. Further heating of hydrogels, up to 250 °C, did not cause other changes associated with weight loss, in contrast with crystalline powder BSA, in which another weight loss at 220 °C was observed, as a result of the beginning degradation. Swelling studies, as well as SEM images, indicated higher crosslink density of BSA gels, compared to HA+BSA samples, which exhibited higher values of swelling ratio. The lowest values of equilibrium swelling ratio were observed at pH 4, which is close to the isoelectric point of albumin. Calculated diffusion coefficients relative to diffusivity of methylene blue in water ranged between the order of 10E-2 for diffusion into physiological solution and the order of 10E-3 for the diffusion into water. Ongoing transport of model dye from gel to solution was significantly slower, compared to its diffusion in water, as a result of gel porosity and electrostatic immobilization of positively charged molecules of methylene blue on the negatively charged BSA and HA chains.
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Metodika dezinfekce fotografických materiálů s albuminovou světlocitlivou vrstvou
Ďurovič, Michal ; Knotek, Vítězslav ; Mašek Benetková, Barbora ; Hricková, Kateřina ; Limpouch, Ondřej ; Nováková, Martina ; Hnulíková, Blanka ; Borýsková, Štěpánka ; Sýkorová, Hana ; Purkrtová, Sabina ; Kadavá, Jana ; Savická, Dana ; Stiborová, Hana ; Branyšová, Tereza ; Demnerová, Kateřina
Uvedená metodika navrhuje postup identifikace historické fotografické techniky, optimální odběrový materiál a techniku odběru vzorku pro mikrobiologickou analýzu, která vychází z doporučení již publikované „Metodiky odběru a izolace bakterií, kvasinek a plísní z fotografických materiálů“ pomocí suchého stěru pomocí měkké polyuretanové (PUR) houbičky. V případě pozitivního výsledku mikrobiologické analýzy jsou navrženy dva postupy samotné dezinfekce - expozice v parách n-butylalkoholu nebo ponor do směsi alkoholů Bacillol AF.
Fulltext:  PDF; PDF
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Influence of surface microstructure on implant lubrication processes in contact
Matovič, Martin ; Odehnal, Lukáš (referee) ; Ranuša, Matúš (advisor)
This bachelor thesis deals with the lubrication of microstructured prostheses of the first metatarsophalangeal joint. The aim of the research is the service life of joint replacements by creating a microstructure on the surface of the material. The work focuses on the influence of microstructures on lubrication processes in contact and coefficient of friction. Fluorescence microscopy in combination with a reciprocating tribometer with the possibility of recording frictional and loaded forces was used to observe the contact area. The number and average particle size of albumin, which plays an important role in contact lubrication, were then examined to record the camera. The testing was performed on two material combinations, namely CoCrMo - Glass B270 (hard pair) and CoCrMo - PMMA (soft pair), which were only four different microstructures. Elsewhere, the influence of microstructures on lubrication processes in contact for hard and soft pairs is indicated, which can be used to design further measurements.
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Optimization of methods for protein analysis released from thermosensitive hydrogel
Lysáková, Klára ; Brtníková, Jana (referee) ; Vojtová, Lucy (advisor)
Předložená diplomová práce je zaměřena na metody hodnocení modelových proteinů (albuminu a lysozymu) a tkáňového léčivého proteinu (stabilního fibroblastového růstového faktoru 2; FGF2-stab) z „inteligentního“ hydrogelového nosiče na bázi biologicky odbouratelného termosenzitivního PLGA-PEG-PLGA triblokového kopolymeru. V teoretické části je zpracován stručný přehled termocitlivých polymerů, jejich vlastnosti, struktura a využití výše uvedených proteinů. Dále jsou zmíněny typy interakcí, které mohou nastat mezi proteiny a polymerními nosiči. V experimentální části byla struktura blokového PLGA-PEG-PLGA kopolymeru charakterizována gelovou permeační chromatografií a 1H NMR, zatímco jeho viskoelastické vlastnosti včetně sol-gel přechodu byly hodnoceny reologickou analýzou. Hlavním cílem práce bylo lepší pochopení uvolňování nově patentovaného FGF2-stab proteinu z injektovatelného PLGA-PEG-PLGA hydrogelu tvořícího při gel při fyziologické teplotě. Množství uvolněného FGF2-stab bylo měřeno UV-VIS spektrofotometrem v přítomnosti Bradfordova činidla, které se váže na proteiny, což vede k posunu jejich absorpčních maxim z 280 nm na 595nm. Pro srovnání byla použita SDS-page elektroforéza, dělící protein podle molekulové hmotnosti. Bylo zjištěno, že modelové proteiny, které byly různé velikosti, ale převážně nepolární povahy, vykazovaly dvoustupňové uvolňování, zatímco FGF2-stab (25 kg.mol-1) vykazoval z PLGA-PEG-PLGA hydrogelu řízené jednostupňové uvolňování, které probíhalo pouhou difúzí, jelikož se jedná převážně o polární molekulu, která se nachází pravděpodobně na povrchu micel, a ne v jejich jádru. Tyto výsledky jsou velmi důležité pro vyladění uvolňování proteinů z hydrogelových nosičů tak, aby vyhovovaly určité aplikaci, v tomto případě řízené regeneraci tkání.
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Genetic and molecular mechanisms of arterial hypertension in relation to chronic inflammation, oxidative stress, and chronic kidney disease
Krajčoviechová, Alena ; Cífková, Renata (advisor) ; Widimský, Jiří (referee) ; Vaněčková, Ivana (referee)
This thesis provides an appraisal of the structure of clustering of metabolic phenotypes and evaluates the pathophysiological mechanisms underlying the relationship between urinary uric acid and albumin excretion. Two population-based studies were involved. In the first part, we used data obtained in a large representative cross-sectional survey in the Czech Republic (Czech post-MONICA study). We showed that the urinary albumin/creatinine ratio (uACR) was an independent factor for an increase in serum uric acid (SUA) levels in adults without manifest metabolic syndrome (MetS), but with 1-2 MetS component(s). Furthermore, SUA levels increased by the synergistic interaction of uACR with visceral adiposity and blood pressure, which may suggest obesity-related hypertension with altered renal hemodynamics as the primary mechanism. In the second part, we analyzed data captured in a representative population sample of French Canadians (CARTaGENE study) with more detailed urine biochemical analyses available. This study yielded two novel observations. First, we showed that the rs13129697 major T allele, which has been associated with increased SUA levels in our analysis as well as in prior publications, was associated with a paradoxical decrease in uACR. The reason for this discrepant finding is the...
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Modification of boron doped diamond electrode by poly-L-lysine and its influence on electrochemical behaviour of dopamine and serotonin
Pejzlová, Michaela ; Fischer, Jan (advisor) ; Vyskočil, Vlastimil (referee)
This bachelor's thesis deals with the redox behavior of two neurotransmitters, dopamine and serotonin, at bare anodically activated (O-terminated) and poly-L-lysine-coated boron doped diamond electrode in two media, namely phosphate buffered saline and Neurobasal (medium commonly used for neuron cultivation experiments). Oxidation of dopamine in tested environments has a quasi-reversible character, while serotonin oxidizes irreversibly on boron doped diamond electrode, both O-terminated and poly-L-lysine-treated. Clearly, poly-L-lysine modification of boron doped diamond electrode leads to a decrease in peak currents and a positive shift in oxidation potentials compared to the O-terminated boron doped diamond electrode; interestingly, serotonin is much more sensitive to polymer coating than dopamine, particularly in Neurobasal medium. During successive measurements, a considerable decrease in recorded signals of both neurotransmitters can be observed. Hence, possibilities how to ensure stable current values were investigated: for dopamine, stirring the solution between the individual scans is sufficient method for obtaining repeatable signals (sr = 1.4-11.9 %, n = 5). However, in case of serotonin it is necessary to reactivate the electrode surface anodically in H2SO4 (Eact = +2400 mV) for 5...
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Oxidative and carbonyl stress in kidney diseases
Kratochvílová, Markéta ; Tesař, Vladimír (advisor) ; Průša, Richard (referee) ; Zadražil, Josef (referee)
Aims: 1. Determination of AGEs (Advanced Glycation End products) in patients with various types of nephropathy. 2. Association AGEs with nutritional parameters and anemia. 3. Influence of renal parameters on sRAGE (soluble form of Receptor for Advanced Glycation End products) levels. 4. Technics and proceeding methods of the podocytes cultivation. 5. Determination of urine podocytes. Methods: We determined fluorescent AGEs by spectrofluorometry, sRAGE by Enzyme-Linked ImmunoSorbent Assay (ELISA). Podocytes were passaged and identified immunocytochemically. Podocytes in urine were specified by flow cytometry method. Results: 1. We did not find significant differences in AGEs serum levels among various types of nephropathy, even though the pathogenesis differs. 2. The albumin and prealbumin levels positively and haemoglobin levels negatively correlate with AGEs in patients with CKD grade 1-5, without necessity of dialysis. 3. Serum sRAGE levels are increased in patients with decreased renal function independently on the course of renal disease. 4. We implemented the methods and technics of podocyte cultivation. 5. Urine podocytes observation and confirmation that podocyturia relates to disease activity. Conclusion: We confirmed that AGEs serum levels depend more on renal function than the type of...
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Relationship of selected indicators of nutritional status and results of oesophageal cancer treatment with chemoradiotherapy and surgery
Zemanová, Milada ; Tvrzická, Eva (advisor) ; Vaňásek, Jaroslav (referee) ; Kazdová, Ludmila (referee)
The impact was assessed of clinical and nutritional factors on prognosis of 107 oesophageal cancer patients treated with neoadjuvant chemoradiotherapy (CHRT) and surgery. Individualised nutritional support, according to grade of dysphagia was carried out in all the patients. Serum leptin, soluble leptin receptors (SLR), TNF, IGF and fatty acid (FA) profiles in plasma phosphatidylcholine (PC) were studied as well. Addition of paclitaxel to carboplatin and continual fluorouracil significantly increased toxicity without influencing efficacy of the treatment. Post-operative node negativity, grade of dysphagia, weight loss and serum albumin were proved to be prognostic factors of survival and time to progression. CHRT led to decrease of SLR, palmitoleic and oleic acid and increase of n-3 polyunsaturated FA in PC. Lower concentrations of SLR were associated with improved survival of the patients. Key words: oesophageal cancer, neoadjuvant chemoradiotherapy, weight loss, paclitaxel, albumin, soluble leptin receptor, fatty acids
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