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8332. In vitro hypoxia increases production of matrix metalloproteinases and tryptase in isolated rat lung mast cells
- Creator:
- Hana Maxová, Jana Novotná, Luděk Vajner, Helena Tomášová, Richard Vytášek, Martin Vízek, Lucie Bačáková, Věra Valoušková, Eliášová, T., and Jan Herget
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Biochemie. Molekulární biologie. Biofyzika, fyziologie, hypoxie, metaloproteiny, plíce, physiology, hypoxia, metalloproteins, lungs, rat lung mast cells, tissue metalloproteinases, tryptase, remodeling of pulmonary vessels, 2, and 577
- Language:
- English
- Description:
- Chronic hypoxia results in hypoxic pulmonary hypertension characterized by fibrotization and muscularization of the walls of peripheral pulmonary arteries. This vessel remodeling is accompanied by an increase in the amount of lung mast cells (LMC) and the presence of small collagen cleavage products in the vessel walls. We hypothesize that hypoxia activates LMC, which release matrix metalloproteinases (MMPs) cleaving collagen and starting increased turnover of connective tissue proteins. This study was designed to determine whether in vitro hypoxia stimulates production of MMPs in rat LMC and increases their collagenolytic activity. The LMC were separated on the Percoll gradient and then were divided into two groups and cultivated for 24 h in 21 % O2 + 5 % CO2 or in 10 % O2 + 5 % CO2. Presence of the rat interstitial tissue collagenase (MMP-13) in LMC was visualized by immunohistological staining and confirmed by Western blot analysis. Total MMPs activity and tryptase activity were measured in both cultivation media and cellular extracts. Exposure to hypoxia in vitro increased the amount of cells positively labeled by anti-MMP-13 antibody as well as activities of all measured enzymes. The results therefore support the concept that LMC are an important source of increased collagenolytic activity in chronic hypoxia., H. Maxová, J. Novotná, L. Vajner, H. Tomášová, R. Vytášek, M. Vízek, L. Bačáková, V. Valoušková, T. Eliášová, J. Herget., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
8333. In vitro study of reactive oxygen species production during photodynamic therapy in ultrasound-pretreated cancer cells
- Creator:
- Hana Kolářová, Bajgar, R., Kateřina Tománková, Krestýn, E., Doležal, L., and Jan Hálek
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, physiology, photodynamic therapy, sonodynamic therapy, phthalocyanine sensitizer, reactive oxygen species, 14, and 612
- Language:
- English
- Description:
- Several recent studies bring evidence of cell death enhancement in photodynamic compound loaded cells by ultrasonic treatment. There are a number of hypotheses suggesting the mechanism of the harmful ultrasonic effect. One of them considers a process in the activation of photosensitizers by ultrasonic energy. Because the basis of the photodynamic damaging effect on cells consists in the production of reactive oxygen species (ROS), we focused our study on whether the ultrasound can increase ROS production within cancer cells. Particularly, we studied ROS formation in ultrasound pretreated breast adenocarcinoma cells during photodynamic therapy in the presence of chloroaluminum phthalocyanine disulfonate (ClAlPcS2). Production of ROS was investigated by the molecular probe CM-H2DCFDA. Our results show that ClAlPcS2 induces higher ROS production in the ultrasound pretreated cell lines at a concentration of 100 μM and light intensity of 2 mW/cm2. We also observed a dependence of ROS production on photosensitizer concentration and light dose. These results demonstrate that the photodynamic effect on breast cancer cells can be enhanced by ultrasound pretreatment., H. Kolářová, R. Bajgar, K. Tománková, E. Krestýn, L. Doležal, J. Hálek., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
8334. In vitro susceptibility studies of Malaysian Plasmodium falciparum isolates and clones against schizontocidal drugs
- Creator:
- Ang, Hooi Hoon, Chan, Kit Lam, and Mak, Joon Wah
- Format:
- Type:
- model:internalpart and TEXT
- Subject:
- Schizontocidal drugs, heterogenous isolates, homogeneous clones, and Plasmodium falciparum.
- Language:
- English
- Description:
- Five Malaysian isolates of the protozoan Plasmodium falciparum Welch were cultured in vitro following the method of Träger and Jensen (1976, 1977) and subsequently cloned using the limiting dilution method of Rosario (1981). Thirty clones were obtained and were later characterized against schizontocidal drugs, chloroquinc, mefloquine and quinine, using the modified in vitro microtechnique. Results showed that these local isolates were heterogenous and most of the clones exhibited similar pattern of susceptibility as their parent isolate except for ST 168 clone and two ST 195 clones that were sensitive but two ST 165 clones, two ST 168 clones and five ST 195 clones were resistant against quinine, respectively. Results also indicated that they were pure clones compared to their parent isolate because their drug susceptibility studies were significantly different (p < 0.05).
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
8335. In vivo assay of P700 redox changes in the cyanobacterium Fremyella diplosiphon and the role of cytochrome c oxidase in regulation of photosynthetic electron transfer
- Creator:
- Schubert, H., Matthijs, H.C.P., and Mur, L.R.
- Format:
- Type:
- model:internalpart and TEXT
- Subject:
- Chlorella pyrenoidosa, pulse amplitude modulation (PAM), photosystem 2, photosystem 1, Passiflora sp., KCN, far-red radiation, and chlorophyli fluorescence
- Language:
- Multiple languages
- Description:
- Photosynthetic and respirátory electron transfers in cyanobacteria not only serve the bioenergetic needs of these prokaryotes during day and night time. The common use of the plastoquinone pool and the cytochrome (cyt) complex also establishes possibilities for sharing photosystem (PS) 2 plus dehydrogenases at the donor side and cyt c oxidase plus PSI at the acceptor side. Given metabolic conditions and radiant energy supply, the available choices may give rise to unusual combinations of connected electron transfer activities, for example PS2 and cyt c oxidase. In vivo measurements of energy storage in PSI cyclic photophosphorylation via photoacoustic spectroscopy, and of the P700 redox statě via absorbance changes at 820 nm detected with the pulse amplitudě modulation technique (PAM), as well as of PS2 fluorescence yield, all in the absence or presence of the cyt c oxidase inhibitor KCN were combined to demonstrate that the two pathways at the acceptor side communicate in vivo. This type of regulation serves proper poising of electron flow through and around PSI. The impaired cyt c oxidase activity (in this study achieved by addition of KCN) prevents a truly oxidized statě of P700 to be reached, which hampers electron passage from PS2. The relative overreduction of PS 1 in the KCN intoxicated samples reduces the electron flow directed to biosynthesis. The results illustrate the versatility of the P700 redox statě measurements at 820 nm as a means to study in vivo electron fluxes in cyanobacteria.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
8336. In vivo evaluation of the high-irradiance effects on PSII activity in photosynthetic stems of Hexinia polydichotoma
- Creator:
- Li, L., Zhou, Z., Liang, J., and Lv, R.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, cylindrical photosynthetic stems, dark adaptation, thermal dissipation, 2, and 581
- Language:
- Multiple languages
- Description:
- Green photosynthetic stems are often responsible for photosynthesis due to the reduction of leaves in arid and hot climates. We studied the response of PSII activity to high irradiance in the photosynthetic stems of Hexinia polydichotoma in the Taklimakan Desert by analysis of the fast fluorescence transients (OJIP). Leaf clips of a chlorophyll fluorometer were used in conjunction with a sponge with a 4-mm-width groove to prevent light leakage for precise in vivo measurements. High irradiance reduced performance indices, illustrating the photoinhibition of PSII to some extent. However, the decrease in active reaction centers (RC) per PSII absorption area and maximum quantum yield indicated a partial inactivation of RCs and an increase in excitation energy dissipation, resulting in downregulation of photosynthetic excitation pressure. In addition, the increased efficiency of electron transport to PSI acceptors alleviated overexcitation energy pressure on PSII. These mechanisms protected the PSII apparatus as well as PSI against damages from excessive excitation energy. We suggested that H. polydichotoma exhibited rather photoadaptation than photodamage when exposed to high irradiance during the summer in the Taklimakan Desert. The experiment also demonstrated that the modified leaf clip can be used for studying dark adaptation in a photosynthetic stem., L. Li, Z. Zhou, J. Liang, R. Lv., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
8337. In vivo study of radioprotective effect of NO-synthase inhibitors and acetyl-L-carnitine
- Creator:
- Andrea Babicová, Havlínová, Z., Hroch, M., Řezáčová, M., Jaroslav Pejchal, Jiřina Vávrová, and Jaroslav Chládek
- Format:
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, ionizující záření, ionizing radiation, acetyl-L-carnitine, aminoguanidine, Nω-nitro-L-arginine methyl ester, 14, and 612
- Language:
- English
- Description:
- Gluteal muscle contracture (GMC) is a chronic fibrotic disease of gluteal muscles due to multiple etiologies. The main pathologic process is characterized by proliferation of fibroblasts and excessive accumulation of collagen in the extracellular matrix of the muscle. Sphingosine-1-phosphate (S1P) is a bioactive sphingolipid and has been reported to be associated with various fibrotic diseases. However, the role of S1P in GMC remains unknown. Here in this articl e, High-perform ance liquid chromatography and immunohistochemistry were applied to evaluate S1P localization and expression in clinical samples from patients with GMC, Quantitative real time PCR, Western blot, and enzyme-linked immunosorbent assa y were used to explore the link between transforming growth factor-β 1 (TGF-β 1), plasminogen activator inhibitor-1 (PAI-1) and S1P. The results showed that S1P was enhanced in contraction band (CB) tissues. Studies using the cell proliferation and transformation assay indicated that exogenous S1P stimulated CB fibroblast proliferation in a time-depen dent manner and in higher concentration also in a dose-dependent manner. Furthermore, we demonstrated that S1P not only promoted collagen type I production, but also up-regulated mRNA and protein expression of transforming growth factor-β 1 and plasminogen activator inhibitor-1. These findings suggest that S1P may regulate increased synthesis of collagen and other fibrogenic factors, and significantly contributes to the process of gluteal muscle scarring in patients with GMC., A. Babicová ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
8338. In vivo study of the effect of antiviral acyclic nucleotide phosphonate (R)-9-[2-(phosphonomethoxy) propyl]adenine (PMPA, tenofovir) and its prodrug tenofovir disoproxil fumarate on rat microsomal cytochrome P450
- Creator:
- Eva Anzenbacherová, Pavel Anzenbacher, Zdeněk Zídek, Evžen Buchar, Eva Kmoníčková, Petr Potměšil, Nekvindová, J., Veinlichová, A., and Antonín Holý
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Biochemie. Molekulární biologie. Biofyzika, fyziologie, cytochromy, physiology, cytochromes, tenofovir, (R)-9-[2-(phosphonomethoxy) propyl]adenine (PMPA), cytochrome P450, CYP2E1, CYP1A2, 2, and 577
- Language:
- English
- Description:
- The total content of rat liver microsomal cytochrome P450 (CYP) significantly decreased after repeated i.p. administration of the antiviral agent tenofovir ((R)-9-[2-(phosphonomethoxy)propyl] adenine) and tenofovir disoproxil at a daily dose 25 mg/kg, although the content of liver microsomal protein did not change. The decrease of the CYP content was accompanied by concomitant increase of the amount of inactive CYP form, cytochrome P420. This effect was confirmed by a parallel study of the activities of selected CYP forms, CYP2E1 (p-nitrophenol hydroxylation) and CYP1A2 (7-ethoxyresorufin deethylation). The activity (expressed relatively to the protein content) of both CYP forms decreased significantly following the decrease of the total CYP. On the other hand, the CYP2E1 activity expressed relatively to the decreasing total CYP content remained unchanged. However, CYP1A2 activity also decreased when calculated relatively to the total native CYP content indicating lower stability of this form. Semiquantitative RT-PCR showed no significant changes in expression of major rat liver microsomal CYP forms after tenofovir treatment. In conclusion, repeated administration of tenofovir in higher doses led to significant decrease of the relative proportion of active liver microsomal CYPs accompanied by a conversion of these enzymes to the inactive form (CYP420) maintaining the sum of CYP proteins unchanged., E. Anzenbacherová, P. Anzenbacher, Z. Zídek, E. Buchar, E. Kmoníčková, P. Potměšil, J. Nekvindová, A. Veinlichová, A. Holý., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
8339. Inactivation and protection of photosystem 2 particles during freezing
- Creator:
- Apostolova, E., Busheva, M., and Tenchov, B.
- Format:
- Type:
- model:internalpart and TEXT
- Language:
- Multiple languages
- Description:
- Prolonged storage of isolated photosystem 2 (PS2)-enriched subchloroplast particles in the frozen statě leads to a decrease of the PS2 activity and to an increase of the energy transfer between chlorophyll (Chl)-proteins of the light-harvesting chlorophyll a/b (LHC)-PS2 complex. The energy transfer was less influenced than the PS2-mediated electron transport at freeze-thaw treatment of PS2 particles. The change of these parameters was not affected by the rate of freezing. The addition of cryoprotectants such as glycerol, trehalose or saccharose in the suspension medium prior to freezing preserved fo a different extent the PS2-mediated electron transport and the energy transfer between the Chl molecules of the LHC-PS2 complex.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
8340. Inactivation of Gi proteins by pertussis toxin diminishes the effectiveness of adrenergic stimuli in conduit arteries from spontaneously hypertensive rats
- Creator:
- Zemančíková, A., Török, J., Josef Zicha, and Jaroslav Kuneš
- Format:
- print, bez média, and svazek
- Type:
- article, články, model:article, and TEXT
- Subject:
- Fyziologie člověka a srovnávací fyziologie, fyziologie, hypertenze, tepny, physiology, hypertension, arteries, pertussis toxin, adrenergic contractions, conduit arteries, angiotensin II, Gi proteins, 14, and 612
- Language:
- English
- Description:
- Treatment with pertussis toxin (PTX) which eliminates the activity of Gi proteins effectively reduces blood pressure (BP) and vascular resistance in spontaneously hypertensive rats (SHR). In this study we have compared the functional characteristics of isolated arteries from SHR with and without PTX-treatment (10 μg/kg i.v., 48 h before the experiment). Rings of thoracic aorta, superior mesenteric artery and main pulmonary artery were studied under isometric conditions to measure the reactivity of these vessels to receptor agonists and to transmural electrical stimuli. We have found that the treatment of SHR with PTX had no effect on endothelium-dependent relaxation of thoracic aorta induced by acetylcholine. In PTX-treated SHR, the maximum contraction of mesenteric artery to exogenous noradrenaline was reduced and the dose-response curve to cumulative concentration of noradrenaline was shifted to the right. Similarly, a reduction in the magnitude of neurogenic contractions elicited by electrical stimulation of perivascular nerves was observed in the mesenteric artery from PTX-treated SHR. PTX treatment of SHR also abolished the potentiating effect of angiotensin II on neurogenic contractions of the main pulmonary artery. These results indicate that PTX treatment markedly diminishes the effectiveness of adrenergic stimuli in vasculature of SHR. This could importantly affect BP regulation in genetic hypertension., A. Zemančíková, J. Török, J. Zicha, J. Kuneš., and Obsahuje bibliografii a bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public