Wyniki wyszukiwania

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Cytotoxicity and cell death: apoptosis or necrosis or both?

100%

Cervinka M., Cervinkova Z., Puza V.

Folia Histochemica et Cytobiologica. Supplement

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1997

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tom 35

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nr 2

2

The effect of drought stress and excessive UV-B radiation on the membrane status in cucumber cotyledons and leaves

84%

Rybus-Zajac M., Korbas A., Kubis J.

Electronic Journal of Polish Agricultural Universities. Series Agronomy

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2017

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tom 20

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nr 4

3

Antioxidant enzyme activities and lipid peroxidation in Mytilus galloprovincialis from the French Mediterranean coast

67%

Gwozdzinski K., Gonciarz M., Kilanczyk E., Kowalczyk A., Pieniazek A., Brichon G.

Oceanological and Hydrobiological Studies

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2010

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tom 39

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nr 4

4

Apoptosis induced by membrane damage in human lymphocytes; effects of arachidonic acid and its photoproducts

67%

Zarebska Z., Zielinska J., Zhukov I., Maslinski W.

Acta Biochimica Polonica

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2005

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tom 52

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nr 1

The effect of arachidonic acid (AA) combined with UVA irradiation was studied in a model system mimicking phototherapy PUVA (psoralen+UVA) ex vivo in vitro. The contribution of damage to the plasma membrane by PUVA was tested on human lymphocytes derived from healthy donors. The effect of arachidonic acid (AA) combined with UVA irradiation was compared with that of a psoralen photoadduct to AA added to the culture. The adduct, obtained photochemically and purified, was characterized by NMR and MS spectrometry as a cycloadduct of psoralen to the vinylene bond of the acid (AA<>PSO). The reactions of cultured cells, manifested 20 h after treatment by changes in apoptosis and mitochondrial depolarization, were monitored by flow cytometry by tagging lymphocytes with appropriate fluorescent probes. Treatment of lymphocyte suspension within AA doses from 40 to 100 μM gradually induced a shift from Anx-V+ (single positive cells) to late apoptotic, Anx-V+PI+ (double positive cells) in a dose dependent manner. The adduct, AA<>PSO, induced apoptotic changes at a concentration 2–3 times higher than free AA. Combination of psoralen (1 μM ) or arachidonic acid (20–120 μM) with UVA irradiation (2–6 J/cm2) accelerated the plasma membrane changes in a synergic way. Preliminary studies indicated that changes in the transmembrane potential of mitochondria paralleled the apoptosis when cells were treated by AA alone. Our findings showed that UVA radiation of lymphocytes in the presence of arachidonic acid, as in the presence of psoralen, enhanced apoptosis of cells in a synergic manner. Thus, PUVA-induced apoptosis may proceed in part by a still undefined signaling pathway(s) triggered in lymphocyte membranes.

5

Decrease in beech [Fagus sylvatica] seed viability caused by temperature and humidity conditions as related to membrane damage and lipid composition

67%

Ratajczak E., Pukacka S.

Acta Physiologiae Plantarum

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2005

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tom 27

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nr 1

The aim of this study was to determine if the loss of germinability and viability of beech (Fagus sylvatica L.) seeds stored at different variants of temperature (4, 20, and 30 °C) and relative humidity (RH: 45 and 75 %) is associated with a loss of membrane integrity and changes in lipid composition. Beech seeds stored for 9 weeks gradually lost viability at a rate dependent on temperature and humidity. The harmful effect of temperature increased with growing humidity. The loss of seed viability was strongly correlated with an increase in membrane permeability and with production of lipid hydroxyperoxides (LHPO), which was regarded as an indicator of peroxidation of unsaturated fatty acids. The condition of membranes was assessed on the basis of their permeability and the state of lipid components: phospholipids and fatty acids. During seed storage we obterved a decline in concentration of individual phospholipids and fatty acids, proportional to the loss of seeds viability. We also detected a decrease in concentrations of α-tocopherol and sterols, which play an important role in protection of membranes against the harmful influence of the environment. Our results show that the germinability of beech seeds declines rapidly at temperature above 0 °C and growing humidity. This is due mainly to the loss ofmembrane integrity, caused by peroxidation of unsaturated fatty acids.

6

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Barley winter hardiness in laboratory and field examinations

67%

Rizza F., Portesi A., Pecchioni N., Terzi V., Stanca A. M.

Genetica Polonica

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1994

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tom 35B