Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "Transition" wg kryterium: Temat

  Lista filtrów
Wyrównaj
    Wyświetlanie 1-9 z 9
    Tytuł:
    Effect of ethanol on structural transitions of DNA and polyphosphates under Ca2+ ions action in mixed solutions.
    Autorzy:
    Hackl, Elene
    Blagoi, Yurij
    Powiązania:
    https://bibliotekanauki.pl/articles/1044400.pdf
    Data publikacji:
    2000
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    DNA transition
    ethanol effect
    polyphosphates
    Opis:
    In the present work using the IR spectroscopy method the effect of ethanol on structural transitions of DNA and polyphosphates under the action of Ca2+ ions in mixed solutions containing ethanol (0-25 vol.%) was studied. It was shown that, on its interaction with Ca2+ ions, in aqueous and mixed solutions DNA becomes transformed into compact form. With the increase of concentration of ethanol the degree of Ca2+-induced DNA compactisation rises. It was found that, in mixed solutions containing ethanol, Ca2+-induced DNA compactisation depends not only on the solution's dielectric permeability but also on the solution structure. On stabilisation of the water structure in the presence of low ethanol concentrations a stabilisation of the DNA macromolecule occurs that leads to the increase of the Ca2+ ion concentration necessary for DNA compactisation. Comparison of the effects of ethanol on Ca2+-induced structural transitions in DNA and polyphosphates in mixed solvents permits to suppose that at alcohol concentrations in solution resulting in disruption of the water spatial structure, some peculiarities are observed in the behavior of those molecules whose hydrophobic interactions are essential.
    Źródło:
    Acta Biochimica Polonica; 2000, 47, 1; 103-112
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Properties of B16-F10 murine melanoma cells subjected to metabolic stress conditions
    Autorzy:
    Mitrus, Iwona
    Bryndza, Ewa
    Kazura, Malgorzata
    Smagur, Andrzej
    Sochanik, Aleksander
    Cichon, Tomasz
    Szala, Stanislaw
    Powiązania:
    https://bibliotekanauki.pl/articles/1039711.pdf
    Data publikacji:
    2012
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    epithelial-mesenchymal transition
    Metabolic stress
    hypoxia
    Opis:
    Neoplastic cells which co-form tumors are usually subjected to various stress factors, mainly hypoxia and shortage of nutrient factors. Such cells employ different strategies that permit their survival under such conditions. Experiments in vitro are usually carried out in the presence of 21% oxygen and medium supplemented with 10% FBS. Altering these parameters can approximate the in vivo conditions found within tumor mass. The present paper reports certain properties (especially ability to metastasize) of B16-F10 cells able to grow upon exposure to altered growth conditions (medium supplemented with 0.06% FBS or presence of 1% oxygen for 24 or 72 hours). These properties were compared with those of control cells cultured in the presence of 21% oxygen and in medium supplemented with 10% FBS. Some properties of the cells exposed to medium supplemented with 0.06% FBS differ from those of cells cultured under low oxygenation conditions (ability to form metastases, to migrate, or to express various proteins). Only the partial deprivation of oxygen did increase both the number of migrating cells and the number of metastases formed. Serum deficiency enhanced only the cell ability to metastasize, but not to migrate. It appears that cultured B16-F10 cells employ different adaptation strategies under conditions of oxygen shortage and those of serum deficiency. Under oxygen deprivation, such cells most likely undergo an epithelial-mesenchymal transition, whereas serum deficiency ("starvation"), while increasing the tumorigenicity of B16-F10 cells, does not induce the epithelial-mesenchymal transition.
    Źródło:
    Acta Biochimica Polonica; 2012, 59, 3; 363-366
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Cd2+-promoted mitochondrial permeability transition: a comparison with other heavy metals.
    Autorzy:
    Belyaeva, Elena
    Glazunov, Vadim
    Korotkov, Sergey
    Powiązania:
    https://bibliotekanauki.pl/articles/1043302.pdf
    Data publikacji:
    2004
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    copper
    mercury
    mitochondrial permeability transition
    respiratory chain
    cadmium
    Opis:
    We compared action of Cd2+, Hg2+, and Cu2+ on isolated rat liver mitochondria in the absence of added Ca2+ and Pi. The heavy-metal ions produced dose-dependently: (1) enhanced membrane permeabilizaton manifested in mitochondrial swelling and activation of basal respiration, (2) inhibition of uncoupler-stimulated respiration, and (3) membrane potential dissipation. Among the metals, Cu2+ exhibited maximal stimulatory effect on basal respiration and minimal inhibitory action on DNP-uncoupled respiration whilst Cd2+ promoted the strongest depression of uncoupled respiration and the largest swelling in NH4NO3 medium. Dithiothreitol induced a basal respiration release if added after high [Cd2+] and [Hg2+], and the stimulation was CsA-insensitive.
    Źródło:
    Acta Biochimica Polonica; 2004, 51, 2; 545-551
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Denaturation and aggregation of lysozyme in water-ethanol solution
    Autorzy:
    Szymańska, Agnieszka
    Hornowski, Tomasz
    Ślósarek, Genowefa
    Powiązania:
    https://bibliotekanauki.pl/articles/1039757.pdf
    Data publikacji:
    2012
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    volumetric studies
    monomer-to-filament structural transition
    lysozyme
    viscosity
    Opis:
    We have applied rheological methods for the analysis of ethanol-lysozyme interaction during the process of denaturation and aggregation of the protein. At low concentration of ethanol a destruction of the hydration shell of lysozyme is observed. With the increase in the ethanol concentration a structural transformation takes place. It leads to the formation of a protein aggregate with an elongated structure. The rheological characteristics of lysozyme-water-ethanol solution changes from Newtonian to pseudoplastic.
    Źródło:
    Acta Biochimica Polonica; 2012, 59, 2; 317-322
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Atomic force microscopy studies of the adhesive properties of DPPC vesicles containing β-carotene
    Autorzy:
    Augustyńska, Dominika
    Jemioła-Rzemińska, Małgorzata
    Burda, Kvetoslava
    Strzałka, Kazimierz
    Powiązania:
    https://bibliotekanauki.pl/articles/1039795.pdf
    Data publikacji:
    2012
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    atomic force microscopy
    dipalmitoylphosphatidylcholine
    β-carotene
    liposome adhesion
    thermal transition
    Opis:
    A role of carotenoids as modulators of physical properties of model and biological membranes has been already postulated. However, there is a lack of information on the influence of these pigments on interactions between the lipids which form such membranes. This paper applies atomic force microscopy (AFM) in to study the effects of β-carotene on the adhesion properties of DPPC multilamellar liposomes. This allowed us to gain, for the first time, a direct insight into the interactions between the components in model systems on a molecular level. We observe that the adhesive forces in DPPC multilamellar liposomes containing 1mol% of β-carotene decrease exponentially with increasing temperature, and that at about 37°C they diminish. In the case of pure liposomes the decline in adhesion is of a different nature and the adhesive forces disappear at 34°C. The adhesive forces are about 5 times higher at 31°C in the presence of β-carotene than in its absence. However, measurements using differential scanning calorimetry (DSC) showed a shift of the lamellar-to-undulled-lamellar phase transition toward lower temperatures by about 0.8±0.2°C in a system containing β-carotene. The enthalpy changes (ΔH) of this transition are similar for both systems. For the main transition, gel-to-liquid crystalline, the peak is shifted by about 0.5±0.1°C, and ΔH decreases by about 30% in liposomes treated with β-carotene in comparison to pure liposomes. Our results suggest increased cooperation between liposome components in a system with enriched β-carotene, which cause a change in phase transition temperatures. Moreover, these interactions are very sensitive to temperature.
    Źródło:
    Acta Biochimica Polonica; 2012, 59, 1; 125-128
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Mitochondrial respiratory chain inhibitors modulate the metal-induced inner mitochondrial membrane permeabilization
    Autorzy:
    Belyaeva, Elena
    Powiązania:
    https://bibliotekanauki.pl/articles/1040305.pdf
    Data publikacji:
    2010
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    copper
    mercury
    stigmatellin
    selenite
    permeability transition pore
    cadmium
    mitochondria
    zinc
    Opis:
    To elucidate the molecular mechanisms of the protective action of stigmatellin (an inhibitor of complex III of mitochondrial electron transport chain, mtETC) against the heavy metal-induced cytotoxicity, we tested its effectiveness against mitochondrial membrane permeabilization produced by heavy metal ions Cd2+, Hg2+, Cu2+ and Zn2+, as well as by Ca2+ (in the presence of Pi) or Se (in form of Na2SeO3) using isolated rat liver mitochondria. It was shown that stigmatellin modulated mitochondrial swelling produced by these metals/metalloids in the isotonic sucrose medium in the presence of ascorbate plus tetramethyl-p-phenylenediamine (complex IV substrates added for energization of the mitochondria). It was found that stigmatellin and other mtETC inhibitors enhanced the mitochondrial swelling induced by selenite. However, in the same medium, all the mtETC inhibitors tested as well as cyclosporin A and bongkrekic acid did not significantly affect Cu2+-induced swelling. In contrast, the high-amplitude swelling produced by Cd2+, Hg2+, Zn2+, or Ca2+ plus Pi was significantly depressed by these inhibitors. Significant differences in the action of these metals/metalloids on the redox status of pyridine nucleotides, transmembrane potential and mitochondrial respiration were also observed. In the light of these results as well as the data from the recent literature, our hypothesis on a possible involvement of the respiratory supercomplex, formed by complex I (P-site) and complex III (S-site) in the mitochondrial permeabilization mediated by the mitochondrial transition pore, is updated.
    Źródło:
    Acta Biochimica Polonica; 2010, 57, 4; 435-441
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The function of complexes between the outer mitochondrial membrane pore (VDAC) and the adenine nucleotide translocase in regulation of energy metabolism and apoptosis.
    Autorzy:
    Vyssokikh, Mikhail
    Brdiczka, Dieter
    Powiązania:
    https://bibliotekanauki.pl/articles/1043614.pdf
    Data publikacji:
    2003
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    cytochrome c
    hexokinase
    free energy
    creatine kinase
    permeability transition pore
    Bax
    Opis:
    The outer mitochondrial membrane pore (VDAC) changes its structure either voltage-dependently in artificial membranes or physiologically by interaction with the adenine nucleotide translocase (ANT) in the c-conformation. This interaction creates contact sites and leads in addition to a specific organisation of cytochrome c in the VDAC-ANT complexes. The VDAC structure that is specific for contact sites generates a signal at the surface for several proteins in the cytosol to bind with high capacity, such as hexokinase, glycerol kinase and Bax. If the VDAC binding site is not occupied by hexokinase, the VDAC-ANT complex has two critical qualities: firstly, Bax gets access to cytochrome c and secondly the ANT is set in its c-conformation that easily changes conformation into an unspecific channel (uniporter) causing permeability transition. Activity of bound hexokinase protects against both, it hinders Bax binding and employs the ANT as anti-porter. The octamer of mitochondrial creatine kinase binds to VDAC from the inner surface of the outer membrane. This firstly restrains interaction between VDAC and ANT and secondly changes the VDAC structure into low affinity for hexokinase and Bax. Cytochrome c in the creatine kinase complex will be differently organised, not accessible to Bax and the ANT is run as anti-porter by the active creatine kinase octamer. However, when, for example, free radicals cause dissociation of the octamer, VDAC interacts with the ANT with the same results as described above: Bax-dependent cytochrome c release and risk of permeability transition pore opening.
    Źródło:
    Acta Biochimica Polonica; 2003, 50, 2; 389-404
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The effect of mono- and divalent cations on Tetrahymena thermophila telomeric repeat fragment. A photon correlation spectroscopy study.
    Autorzy:
    Włodarczyk, Agnieszka
    Patkowski, Adam
    Grzybowski, Przemysław
    Dobek, Andrzej
    Powiązania:
    https://bibliotekanauki.pl/articles/1041510.pdf
    Data publikacji:
    2004
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    chromosome ends
    G-quadruplex
    telomeric DNA
    photon correlation spectroscopy
    structure transition
    Opis:
    The structure of the Tetrahymena thermophila telomeric sequence d(TGGGGT)4 was studied by photon correlation spectroscopy (PCS) in aqueous solution in the presence of NaCl, KCl and SrCl2. The sample studied was polydisperse in all conditions studied. Translational diffusion coefficients DT describing the diffusion modes observed were determined. On the basis of a comparison between the experimental DT values with those calculated assuming the bead model, two forms were identified as telomeric quadruplex structures: monomer and tetramer. In the presence of SrCl2 formation of aggregates was observed, with a size that reached several micrometres. The relative weighted concentrations of the structures observed for different concentrations of a salt and DNA were determined. The results obtained in the presence of monovalent ions were qualitatively similar and could be presented in a coherent plot in which the concentration of salt was expressed by the number of ions per DNA molecule. A large number of ions per DNA molecule favoured tetramer formation while a small number favoured the monomer form. A structural phase transition from the monomer to the tetramer induced by a change in the number of ions per DNA molecule was observed. The main difference between the results for Na+ and K+ was a greater effectiveness of the K+ ions in formation of tetramers. The effect of Sr2+ ions on the structures formed was different than that of the monovalent ions. The results obtained in the presence of Sr2+ could not be described as a function of the number of ions per DNA molecule.
    Źródło:
    Acta Biochimica Polonica; 2004, 51, 4; 971-981
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Pentoxifylline and its active metabolite lisofylline attenuate transforming growth factor β1-induced asthmatic bronchial fibroblast-to-myofibroblast transition
    Autorzy:
    Wójcik-Pszczoła, Katarzyna
    Hińcza, Kinga
    Wnuk, Dawid
    Kądziołka, Dominika
    Koczurkiewicz, Paulina
    Sanak, Marek
    Madeja, Zbigniew
    Pękala, Elżbieta
    Michalik, Marta
    Powiązania:
    https://bibliotekanauki.pl/articles/1038759.pdf
    Data publikacji:
    2016
    Wydawca:
    Polskie Towarzystwo Biochemiczne
    Tematy:
    theophylline
    pentoxifylline
    lisofylline
    transforming growth factor type β
    fibroblast-to-myofibroblast transition
    asthma
    Opis:
    Bronchial asthma is characterized by persistent airway inflammation and airway wall remodeling. Among many different cells and growth factors triggering changes in bronchi structure, transforming growth factor β1-induced fibroblast to myofibroblast transition is believed to be very important. The aim of this study was to evaluate whether theophylline (used in asthma therapy) and two other methylxanthines (pentoxifylline and its active metabolite lisofylline), may affect transforming growth factor β1-induced fibroblast to myofibroblast transition in bronchial fibroblasts derived from asthmatic patients. We show here for the first time that selected methylxanthines effectively reduce transforming growth factor β1-induced myofibroblast formation in asthmatic bronchial fibroblast populations. PTX was found to be the most effective methylxanthine. The number of differentiated myofibroblasts after PTX, LSF and THEO administration was reduced at least twofold. Studies on the use of methylxanthines opens a new perspective in the development of novel strategies in asthma therapy through their two-pronged, anti-inflammatory and anti-fibrotic action. In the future they can be considered as promising anti-fibrotic drugs.
    Źródło:
    Acta Biochimica Polonica; 2016, 63, 3; 437-442
    0001-527X
    Pojawia się w:
    Acta Biochimica Polonica
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-9 z 9

      Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies