National Repository of Grey Literature 37 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Influence of tumor microenvironment, cellular and humoral immunity on cancer pathogenesis.
Špaček, Jan ; Závadová, Eva (advisor) ; Petráková, Katarína (referee) ; Kopečková, Kateřina (referee)
Cancer is the second leading cause of death in the Czech Republic. Breast cancer and colorectal cancer have relatively high mortality rate. One of the areas of current clinical research in oncology is the study of prognostic biomarkers, which aims to optimize the decision-making process for a patient. Immune response and processes in the tumor microenvironment have been shown to influence to a large extent the biological nature of the tumor in terms of its aggressiveness and ability to metastasize in the host's body. There are certain tumors that could induce a strong immune response, while others do not. The ability to induce an anti-tumor cell response and to attract specific lymphocyte subpopulations directly into tumor tissue has been shown to be very closely related to the prognosis of cancer patients. There is evidence and correlation of the presence of so-called tumor infiltrating lymphocytes in tumor tissue and overall patient survival. Stratification of cancer patients based on immuno-predictors both in the plasma and directly in the tumor microenvironment makes it possible to identify suitable candidates for rediscovered modern anti-tumor immunotherapy, which can already be considered a standard therapeutic modality. In our projects, we focused on the identification of biomarkers that...
Generation of realistic skydome images
Špaček, Jan ; Wilkie, Alexander (advisor) ; Pilát, Martin (referee)
Generation of realistic skydome images We aim to generate realistic images of the sky with clouds using generative adversarial networks (GANs). We explore two GAN architectures, ProGAN and StyleGAN, and find that StyleGAN produces significantly better results. We also propose a novel architecture SuperGAN which aims to generate images at very high resolutions, which cannot be efficiently handled using state-of-art architectures. 1
Utilization of Catalytic Hydrogen Evolution in Electrochemical Analysis of Nucleic Acids
Fojta, Miroslav ; Daňhel, Aleš ; Špaček, Jan ; Havran, Luděk ; Šebest, Peter ; Orság, Petr ; Pivoňková, Hana ; Vosáhlová, J. ; Schwarzová-Pecková, K.
Catalysis of hydrogen evolution (CHE) at mercury in the presence of proteins was discoverd shortly after the introduction of polarography. In contrast, unmodified nucleic acids have not been reported to produce distinct signals due to the CHE to date. Chemically modified nucleic acids bearing certain extrinsic groups produce analytically useful signals due to hydrogen evloution catalyzed by the respective modifications. These species include (a) transition metal complexes, and (b) non-metal catalytically active organic moieties. In addition, the CHE has been reported to be invoved in guanine reduction process at the mercury-based electrodes.
Enzymatic Incorporation of Biotin into DNA for DNA Hybridization Analysis and for Sensitive Detection of PCR-Amplified DNA
Špaček, Jan ; Zenka, Martin ; Haroniková, Lucia ; Havran, Luděk ; Fojta, Miroslav
We present two enzymatical electrochemical assays for DNA analysis. For hybridization analysis we used probes with biotin-14-dC introduced to 3' OH end by terminal transferase. For detection of PCR products we used Deep Vent polymerase to incorporate biotin-14-dCduring PCR. In both cases streptavidin-alkaline phosphatase conjugate was subsequently attached to the incorporated biotins and was used to catalyze dephosphorylation of 1-naphthyl phosphate to 1-naphthol, the electrochemical signal of which was utilized for detection. Compared to the former method, biotin incorporation during PCR offers lower molar detection limits, whereas application of the biotin-tailed probe can provide us with more selective detection.
Haroniková, Lucia ; Špaček, Jan ; Fojta, Miroslav
In this work, we present a new qualitative approach of detection of PCR products using electrochemistry on pencil electrodes. PCR products with an incorporated biotin-labeled dNTP (dCTP in this study) are detected via conjugated streptavidinealkaline phospatase. 1-Naphthyl phosphate (1-NP), which is dephosphorylated by alkaline phosphatase to release 1-naphthol, was used as a substrate in electrochemical detection of the PCR product. Voltammetric measurement on disposable pencil electrode is a very cheap and easy to use method. The system was optimized for plasmid DNA PCR product with potential to detect human genome DNA products and possible application in gene deletion monitoring.
Hermanová, Monika ; Špaček, Jan ; Orság, Petr ; Fojta, Miroslav
A novel assay for detection of DNA-protein binding has been developed. Oligonucleotides bearing or lacking specific binding site of the p53 protein were tail-labeled by two different modified deoxynucleotide triphosphates using terminal deoxynucleotidyl transferase. Electrochemical detection enabled to discriminate between sequence-specific and non-specific p53-DNA binding in a competition assay.
Possibility of Using Purine Oxidation Signals for DNA Sequence Analysis
Špaček, Jan ; Cahová, Kateřina ; Havran, Luděk ; Fojta, Miroslav
Signals provided by electrochemical oxidation of single stranding DNA on the surface of pyrolytic graphite electrode, which correspond to the oxidation of adenine and guanine (A and G) are known for over forty years. The mechanism of oxidation of free A and G as well as nucleoside mono-, and triphosphates of these bases is know but the mechanism of oxidation of purines in the DNA still remains unexplained. Ratiometry of A and G signals could be a new tool for DNA sequence analysis, if signals of A and G oxidation obtained from single-stranded DNA adsorbed at the electrode surface are proportional to the number of oxidized As and Gs in studied samples. Our preliminary results suggest that there is a correlation, yet we encountered problems, which yet has to be addressed and explained before this method could be applied for DNA analysis.
Examples of Using of Electrochemical Detection at Pencil Graphite Electrode with Enzymatic Labeling for Analysis of Nucleotide Sequence
Plucnara, Medard ; Haroniková, Lucia ; Špaček, Jan ; Havran, Luděk ; Horáková, Petra ; Pivoňková, Hana ; Ecsin, E. ; Erdem, A. ; Fojta, Miroslav
Many examples of utilization of enzymatic labeling for DNA sequence analysis has been described in literature so far. Some of them involve hybridization with complementary biotinylated probe, while others use incorporation of biotinylated nucleotides into DNA strand by DNA polymerases. Common approach is then binding of streptavidine-enzyme conjugates to biotin tags and incubation with substrate, which is converted to detectable product. Here, two recent applications using this principle are described for the detection of PCR amplicons and for SNP typing. Both techniques are combined with detection at pencil graphite electrodes.
Studies of Protein-DNA Interactions using Immunoprecipitation with DNA Probes Labelled with Electroactive Groups
Hermanová, Monika ; Špaček, Jan ; Pivoňková, Hana ; Fojta, Miroslav
Different electrochemically active species were tested for labelling of DNA probes and detection of DNA-protein binding. As the DNA probes, oligonucleotides bearing or lacking specific binding site of the p53 protein were chosen. They were tail-labelled either via chemical modification of single-stranded (ss) oligo(dT) DNA tails with an oxoosmium complex, or via enzymatic synthesis of the ss tail by terminal deoxynucleotidyl transferase and deoxynucleoside triphosphates modified with electrochemically reducible moieties. Electrochemical detection enabled to discriminate between sequence-specific and non-specific p53-DNA binding.
Natural and Synthetic Components of Nucleic Acids as Reactive Sites for DNA Modification by Osmium Tetroxide Complexes
Havran, Luděk ; Špaček, Jan ; Rozkosna, Jana ; Fojta, Miroslav
Natural DNA electroactivity find wide use in electrochemical analysis of its interactions and damage. For some applications is useful applied redox active tag to improve specificity of the analysis. One from utilized labels in this field are complexes of osmium tetroxide with nitrogen ligands (Os, L), which produce with DNA electroactive covalent adducts. Prime reaction site for Os, L is C=C double bond in pyrimidine nucleobases. If is 2,2'-bipyridine used as ligand, reaction is specific for single strand DNA. In this contribution will be presented results of electrochemical analysis of Os, bipy adducts with different ODN containing chemically modified purine bases.

National Repository of Grey Literature : 37 records found   1 - 10nextend  jump to record:
See also: similar author names
25 ŠPAČEK, Jan
3 Špaček, Jakub
1 Špaček, Jaroslav
2 Špaček, Jindřich
5 Špaček, Jiří
1 Špaček, Josef
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