Number of results to display per page
Search Results
4062. Čekání na Fórum
- Creator:
- Hnídková, Vendula
- Type:
- article, model:article, and TEXT
- Language:
- Czech
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4063. Celek, Prostor, Cíl: eurasijský totalitarismus průkopníků strukturalismu
- Creator:
- Glanc, Tomáš
- Format:
- Type:
- model:internalpart and TEXT
- Language:
- Czech
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4064. Celkem dvacet palců
- Creator:
- Čestek, František
- Type:
- article, model:article, and TEXT
- Language:
- Czech
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4065. Cell Adhesion on Artificial Materials for Tissue Engineering
- Creator:
- Bačáková, L., Filová, E., Rypáček, F., Švorčík, V., and Starý, V.
- Type:
- article, model:article, and TEXT
- Subject:
- Biomaterials, Bioinert, Bioactive, Integrins, and Adhesion Oligopeptides
- Language:
- English
- Description:
- Advanced interdisciplinary scientific field of tissue engineering has been developed to meet increasing demand for safe, functional and easy available substitutes of irreversibly damaged tissues and organs. First biomaterials were constructed as “two-dimensional” (allowing cell adhesion only on their surface), and durable (non-biodegradable). In contrast, biomaterials of new generation are characterized by so-called three dimensional porous or scaffold-like architecture promoting attachment, growth and differentiation of cells inside the material, accompanied by its gradual removal and replacement with regenerated fully functional tissue. In order to control these processes, these materials are endowed with a defined spectrum of bioactive molecules, such as ligands for adhesion receptors on cells, functional parts of natural growth factors, hormones and enzymes or synthetic regulators of cell behavior, incorporated in defined concentrations and spatial distribution against a bioinert background resistant to uncontrolled protein adsorption and cell adhesion.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4066. Cell Cycle Alteration, Apoptosis and Response of Leukemic Cell Lines to Gamma Radiation with High- and Low-Dose Rate
- Creator:
- Vávrová, J., Řezáčová, M., Vokurková, D., and Psutka, J.
- Type:
- article, model:article, and TEXT
- Subject:
- Leukemia cell line, Ionizing radiation, Apoptosis, and G2 arrest :D
- Language:
- English
- Description:
- The aim of this work was to compare the effect of gamma radiation with sub-low dose-rate 1.8 mGy/min (SLDR), low dose-rate 3.9 mGy/min (LDR) and high dose-rate 0.6 Gy/min (HDR) on human leukemic cell lines with differing p53 status (HL-60, p53 deficient and MOLT-4, p53 wild) and to elucidate the importance of G2/M phase cell cycle arrest during irradiation. Radiosensitivity of HL-60 and MOLT-4 cells was determined by test of clonogenity. Decrease of dose-rate had no effect on radiosensitivity of MOLT-4 cells (D0 for HDR 0.87 Gy, for LDR 0.78 Gy and for SLDR 0.70 Gy). In contrast, a significant increase of radioresistance after LDR irradiation was observed for p53 negative HL-60 cells (D0 for HDR 2.20 Gy and for LDR 3.74 Gy). After an additional decrease of dose-rate (SLDR) D0 value (2.92 Gy) was not significantly different from HDR irradiation. Considering the fact that during HDR the cells are irradiated in all phases of the cell cycle and during LDR mainly in the G2 phase, we have been unable to prove that the G2 phase is the most radiosensitive phase of the cell cycle of HL-60 cells. On the contrary, irradiation of cells in this phase induced damage reparation and increased radioresistance. When the dose-rate was lowered, approximately to 1.8 mGy/min, an opposite effect was detected, i.e. D0 value decreased to 2.9 Gy. We have proved that during SLDR at first (dose up to 2.5 Gy) the cells accumulated in G2 phase, but then they entered mitosis or, if the cell damage was not sufficiently repaired, the cells entered apoptosis. The entry into mitosis has a radiosensibilizing effect.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4067. Cell kinetics of aortic smooth muscle cells in long-term cultures prepared from rats raised under conventional and SPF conditions
- Creator:
- Bačáková, L. and Mareš, V.
- Type:
- article, model:article, and TEXT
- Subject:
- vascular smooth muscle cells, cell migration and cell proliferation, cell cycle and growth fraction, breeding conditions, and rat
- Language:
- English
- Description:
- Migration and proliferation of smooth muscle cells (SMC) were studied in cultures prepared from the aorta of Wistar male rats (170—200 g b.w., 8 weeks old) raised under conventional (CC) or specific pathogen-free (SPF) conditions. In primary cultures, higher movement of cells from explants was found in CC raised donors, namely in samples cultured in serum incomplete medium. In the following subcultures (passage 3—16), the growth curves were steeper and the doubling time shorter in CC type of cultures. The faster growth of SMC population from conventional donors was found to be due to a shorter cell cycle and a higher proportion of dividing cells. As a consequence, the maximum population densities were also higher in the latter type of cultures. The differences in growth, that were dependent on raising conditions, were evident for 16 passages, i.e. 7 months after explantation of cells into culture. The data suggest that breeding conditions may affect the activation of growth of SMC in blood vessels in situ.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4068. Cell membrane-bound proteases: not "only" proteolysis
- Creator:
- Šedo, A., Mandys, V., and Křepela, E.
- Type:
- article, model:article, and TEXT
- Subject:
- protease, cell membrane, and integral membrane protein
- Language:
- English
- Description:
- Ectopcptidases are widely distributed among various cell systems. Their expression on an appropriate cell type is finely regulated, reflecting the specific functional cell implications and engagement in defined physiological pathways. Protein turnover, ontogeny, inflammation, tissue remodelling, cell migration and tumor invasion arc among the many physiological and pathological events in which cell- surface proteases play a crucial role, both as effector as well as regulatory molecules. It has recently become clear that also non-catalytic effects of membrane-bound proteases are of great importance in some biological regulations. They may generate specific signal transduction intracellularly, after reacting with certain target molecules. They may also play a pivotal role in cell-cell and cell-virus contact and recognition, as well as in binding to the extracellular matrix. This short review provides some insight into the multifunctional mechanisms attributed to cell membrane-bound proteases.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4069. Cell surface enzymes of brain cortex cells or lymphocytes during early allogeneic reaction
- Creator:
- Kovářů, H., Kovářů, F., and Hašková, V.
- Type:
- article, model:article, and TEXT
- Subject:
- H-2 allorecognition, astrocytes, C-6 glioma cells, lymphocytes, Na+,K+-ATPase activation, and Na+,K+-ATPase and MHC Class II antibody interaction
- Language:
- English
- Description:
- The aim was to study the role of major histocompatibility complex (MHC), in mice named H-2, during early allogeneic reactions (AR) of brain cortex cells or lymphocytes. We used neuronal and glial enriched perikarya, spleen and thymus lymphocytes or their subpopulations. Rat AR was also assayed between C-6 astrocytoma cells and spleen lymphocytes. We demonstrated that: 1) H-2 dependent stimulation of Na+,K+-ATPase and ouabain- sensitive K+-dependent p-nitrophenylphosphatase (K+-pNPPase) activities represented specific response in both AR of unseparated brain cells or lymphocytes. On the other hand, non-specific AR-induced stimulation of Ca2 + - ATPase activity was observed. 2) Allogeneic enriched glial fractions reacted similarly by the same enzyme activation in contrast to no change in AR between enriched neuronal fractions. Allorecognition ability of glial cells was confirmed by AR between C-6 astrocytoma cells and lymphocytes. 3) Mature thymus lymphocytes exerted alloreactivity by specific activation of Na+,K+-ATPase or K+-pNPPase, in contrast to no change in AR between immature lymphocyte subpopulations. 4) MHC Class II monoclonal antibody inhibited Na+,K+-ATPase and K+-pNPPase activities in brain cells as well as in thymus and spleen lymphocytes in a dose-dependent manner. Results support former studies about alloantigen-induced uncoupling in brain oxidative cortex metabolism (Kovářů Med. Biol. 58: 273, 1980) via Na+,K+-ATPase and K+-pNPPase inhibition by mechanism which can mimic MHC restriction.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
4070. Cell-tak coating interferes with DNA-based normalization of metabolic flux data
- Creator:
- Sima, Michal, Martinkova, Stanislava, Kafkova, Anezka, Pala, Jan, and Trnka, Jan
- Format:
- počítač and online zdroj
- Type:
- model:article and TEXT
- Subject:
- metabolic flux analysis, normalization, and Cell-Tak
- Language:
- English
- Description:
- Metabolic flux investigations of cells and tissue samples are a rapidly advancing tool in diverse research areas. Reliable methods of data normalization are crucial for an adequate interpretation of results and to avoid a misinterpretation of experiments and incorrect conclusions. The most common methods for metabolic flux data normalization are to cell number, DNA and protein. Data normalization may be affected by a variety of factors, such as density, healthy state, adherence efficiency, or proportional seeding of cells. The mussel-derived adhesive Cell-Tak is often used to immobilize poorly adherent cells. Here we demonstrate that this coating strongly affects the fluorescent detection of DNA leading to an incorrect and highly variable normalization of metabolic flux data. Protein assays are much less affected and cell counting can virtually completely remove the effect of the coating. Cell-Tak coating also affects cell shape in a cell line-specific manner and may change cellular metabolism. Based on these observations we recommend cell counting as a gold standard normalization method for Seahorse metabolic flux measurements with protein content as a reasonable alternative.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public