The project focuses on dietary interventions in type 2 diabetes(T2D). The aim was to investigate how glucose metabolism and other manifestations of insulin resistance should be influenced by a) the composition of macronutrients and b) frequency of meals; and to characterize the possible mechanisms of these dietary interventions in patients with T2D. A. In a randomized crossover study, 50 patients T2D and 50 age-matched healthy subjects underwent in a random order meal tolerance tests with three isocaloric meals (vegan sandwich; V-meal, hamburger; M-meal, or cheese sandwich; S-meal. Blood samples for analysis were taken at time 0 and after 30, 60, 120 and 180 minutes after meal ingestion. Plasma concentrations of plasma glucose, insulin, C-peptide, lipids, oxidative stress markers and gastrointestinal hormones (GIHs) were investigated. Both basal and postprandial plasma concentrations of glucose and insulin were significantly higher in patients with T2D (p<0.001); basal and postprandial concentrations of almost all other GIHs (except for ghrelin) and thiobarbituric acid reactive substances (TBARS) were significantly increased (p<0.001), while ascorbic acid, reduced glutathione and superoxide dismutase activity were decreased in patients with T2D compared to healthy controls (p<0.001). The meal rich...

Nanočástice perovskitů halogenidů kovů vykazují unikátní vlastnosti, především výjimečně vysoké hodnoty kvantových výtěžků fluorescence, které předurčují tyto materiály pro aplikace v optoelektronických a fotonických zařízeních. Tato práce popisuje přípravu nanočástic perovskitů halogenidů kovů pomocí stabilizačních činidel inspirovaných přírodou. Stabilizační činidla zde slouží nejen ke stabilizaci, ale i k modifikaci povrchu nanočástic za účelem zvýšení funkčnosti výsledných nanostruktur. Úvod práce popisuje optimalizaci přípravy nanočástic precipitační technikou za použití stabilizačních činidel; jako stabilizační činidlo byl zvolen adamantan-1-amin spolu s hexanovou kyselinou. Bylo prokázáno, že klíčový vliv na optické vlastnosti výsledných koloidních roztoků má volba rozpouštědel a teploty při precipitaci. Mimo jiné byl zkoumán vliv koncentrace prekurzorů na výslednou morfologii a optické vlastnosti nanočástic a jejich koloidních roztoků. V neposlední řadě byly nanočástice stabilizovány adamantan-1-aminem spolu s různými karboxylovými kyselinami a byly studovány optické vlastnosti a koloidní stabilita výsledných koloidních roztoků. V dalším kroku byly nanočástice perovskitů stabilizovány pomocí proetogenních aminokyselin L-lysinu and L-argininu. Takto stabilizované nanočástice vykazovaly úzká emisní spektra ve viditelné oblasti a kvantové výtěžky fluorescence dosahující hodnot téměř 100 %. Stabilizace nanočástic prostřednictvím postranních skupin aminokyselin byla prokázána navázáním chránící terc-butoxykarbonylové skupiny na -amino skupinu. Nanočástice stabilizované modifikovaným lysinem v průběhu jejich přípravy vykazovaly závislost optických vlastností na přítomnosti vody. Předpokládá se, že molekuly vody jsou schopné kontrolovat růst krystalové mřížky po navázání na prekurzory perovskitů a ovlivňovat tak výslednou velikost nanočástic, což vede k projevení kvantových jevů. Spojení nanočástic perovskitů s peptidy představuje nový typ materiálů kombinujících výjimečné optické vlastnosti se samoorganizačními a senzorickými vlastnostmi. Tento koncept byl představen přípravou nanočástic perovskitů stabilizovaných cyklo(RGDFK) pentapeptidem. Vzhledem k citlivosti peptidů na jejich byly nanočástice stabilizovány peptidovými nukleovými kyselinami, robustními analogy nukleových kyselin. Ke stabilizaci nanočástic byl připraven monomer a trimer peptidové nukleové kyseliny obsahující thymin jako dusíkatou bázi. Thymin byl na povrchu nanočástic dostupný k interakci s adeninem přes vodíkové můstky umožňující přenos náboje. Kombinace peptidových nukleových kyselin a perovskitů s unikátními optickými vlastnostmi otevírá aplikační možnosti zejména v oblasti optických senzorů.

The dissertation thesis focuses on the application of activated carbon for the removal of low molecular weight algal organic matter (AOM) produced by phytoplankton during drinking water treatment, as well as on the effect of AOM on adsorption of anthropogenic micropollutants contained in raw water. The results of this study have been published in international peer-reviewed journals in 4 papers and in 2 conference contributions. The efficiency of AOM removal was studied in laboratory equilibrium and kinetic experiments using different types of granular activated carbon and cellular peptides with molecular weight < 10 kDa produced by cyanobacterium Microcystis aeruginosa. It has been previously confirmed that these peptides are removed with difficulty during the conventional water treatment based on coagulation/flocculation processes and therefore, other methods need to be applied for their restriction. The effect of solution properties on peptide adsorption was assessed by the tests at different pH values and at variable ionic strengths. The negative impact of peptides on the adsorption of organic micropollutants present in raw water was simulated using competitive adsorption experiments with herbicides alachlor and...

The avian immune system is a complex system of defence mechanisms that protect bird hosts against threats from ubiquitous pathogens. According to the co-evolutionary models, variability in immune traits of hosts is the key component providing ability to adapt and enhance their defence mechanisms in presence of constant selective pathogen pressure. Domestic chicken (Gallus gallus f. domestica) is used as a model organism in avian biology and also is one of the most important food-producing animals, not only for their meat but also for the egg production. Unfortunately, in research usually only inbred chicken lines are used and modern poultry husbandry is tight with unilateral breeding towards highly productive breeds. Those approaches decrease intra-population polymorphism in chickens. However, especially in case of farm animals, searching and extending the pool of immune variability and enhancing pathogen resistance is crucial for sustaining healthy and biologically secure populations and their products. Morphologically highly distinct traditional chicken breeds, which have evolved for hundreds years under different selective pressures, may represent this desirable immunological variability. In my thesis I described variability in chosen immunological traits, haematological parameters and proteomic...

The Ph.D. thesis deals with the characterization of algal organic matter (AOM), which is difficult to remove in water treatment, and on the basis of AOM character, various methods for its elimination, e.g. coagulation, oxidation with subsequent coagulation and adsorption onto activated carbon are assesed. Special emphasis is placed on identifying the optimal conditions of the processes and on describing the mechanisms and interactions involved. In terms of anthropogenic micropollutants, the thesis deals with the highly topical issue of the occurrence of microplastics in water. It was found that the removal efficiency of the individual AOM components varies substantially depending on the elimination method used. The identified optimum conditions of individual methods and especially the mechanisms that apply to the removal of target substances varied widely. The non-proteinaceous fraction of AOM was removed with very low efficiency (max. 25%) by conventional coagulation even under optimized conditions (pH 6.6- 7.5 for aluminium sulfate as the coagulating agent and pH 7.5-9.0 for polyaluminium chloride) and it was given by the high content of low molecular weight (LMW) substances that are difficult to coagulate. The dominant coagulation mechanism was adsorption onto aluminium hydroxide precipitates....

The avian immune system is a complex system of defence mechanisms that protect bird hosts against threats from ubiquitous pathogens. According to the co-evolutionary models, variability in immune traits of hosts is the key component providing ability to adapt and enhance their defence mechanisms in presence of constant selective pathogen pressure. Domestic chicken (Gallus gallus f. domestica) is used as a model organism in avian biology and also is one of the most important food-producing animals, not only for their meat but also for the egg production. Unfortunately, in research usually only inbred chicken lines are used and modern poultry husbandry is tight with unilateral breeding towards highly productive breeds. Those approaches decrease intra-population polymorphism in chickens. However, especially in case of farm animals, searching and extending the pool of immune variability and enhancing pathogen resistance is crucial for sustaining healthy and biologically secure populations and their products. Morphologically highly distinct traditional chicken breeds, which have evolved for hundreds years under different selective pressures, may represent this desirable immunological variability. In my thesis I described variability in chosen immunological traits, haematological parameters and proteomic...

Rapid development of bacterial resistance and multiresitance to conventional antibiotics has resulted in an intensive search for alternative antimicrobial agents. Antimicrobial peptides (AMPs) belong to promising anti-infective candidates since they do not development bacterial resistance. They kill microbes by disturbing or permeabilizing the cytoplasmic membrane, or may target putative key intracellular compartments. Their advantages include fast action and selectivity between prokaryotic and eukaryotic cells. We have isolated several novel AMPs from the venom of wild bees: halictines (HAL-1 and HAL-2) from Halictus sexcinctus, lasiocepsin (Las) from Lasioglossum laticeps and macropin (MAC-1) from Macropis fulvipes. They are active against Gram-positive and Gram- negative bacteria and against yeast Candida albicans. While halictines and macropin have moderate hemolytic activity, Las shows no hemolytic activity. A novel AMP was isolated also from the mucus of Xiphydria camelus. This AMP belongs to the category of insect defensins. It contains 55 amino acid residues, three disulphide bridges and its C-terminus is amidated. CD and NMR studies of HAL-1, HAL-2 and MAC-1 revealed propensity to form amphipathic α-helical structure in the presence of sodium dodecyl sulfate or trifluoroethanol. For the...

This study investigated characteristics of algal organic matter (AOM) derived from four species (cyanobacteria Microcystis aeruginosa and Merismopedia tenuissima, diatom Fragilaria crotonensis and green alga Chlamydomonas geitleri) dominating phytoplanktonic populations in the reservoirs supplying drinking water treatment plants - the water reservoirs Švihov (the Želivka water treatment plant) and Josefův Důl (the Jizerské Mountains), Czech Republic. The four mentioned microorganisms were cultivated under laboratory conditions and the algal growth was quantified by a number of cells, chrorophyll-a and optical density. Production of AOM was evaluated by dissolved organic carbon concentration measurements, by specific UV absorbance, the amount of peptide/protein and non-peptide (carbohydrate) contents, water affinity and molecular weight (MW). AOM of all considered microorganisms are formed predominantly by hydrophilic substances with low values of specific UV absorbance (< 2 L/(m.mg)). Considerable portions of both types of AOM, i.e. extracellular and cellular organic matters are represented by substances with MW < 1 kDa or with MW > 100 kDa. However, the total amount and composition of AOM significantly depend on algal species and their growth. The obtained results imply that the knowledge of AOM...

The MHC class I status of tumour cells during immunotherapy is often underestimated. It represents one of important tumour escape mechanisms and thus can contribute to the failure of most of the cancer clinical trials that are usually based on the induction of cytotoxic T cell responses. Epigenetic changes in the promoters of genes involved in the MHC class I Ag presentation can result in decreased expression of the cell surface MHC molecules on tumour cells. Thus, epigenetic modifiers can restore an expression of the MHC class I molecules and make tumours visible to the CD8+ effector cells. Besides the epigenetic changes on the tumour cells, epigenetic modulators affect cells of the immune system such as dendritic cells (DC). Tumour cells can escape from the immune response not only by changes in the cancer cells, but also by influencing, expanding and/or activating immunoregulatory cell populations, such as regulatory T cells (Treg). This thesis focuses on the potential of the DC-based vaccines against HPV-16-associated tumours with a different MHC class I expression, on the combination of cancer immunotherapy with the treatment using epigenetic modifiers, with special attention paid to their effects on DC, and, finally, on the impacts of the anti-CD25 antibody (used for Treg elimination) on Treg and NKT...