Preferencje help
Polish version English version Język
Widoczny [Schowaj] Abstrakt
Liczba wyników

Znaleziono wyników: 12

Liczba wyników na stronie
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników

Wyniki wyszukiwania

Wyszukiwano:
w słowach kluczowych:  porphyrin
help Sortuj według:

help Ogranicz wyniki do:
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
1

Photodynamic effect of lanthanide derivatives of meso-tetra[N-methyl-4-pyridyl]porphine against Staphylococcus aureus

100%
Jurczak A., Szramka B., Grinholc M., Legendziewicz J., Bielawski K. P.
Acta Biochimica Polonica
|
2008
|
tom 55
|
nr 3
581-585
Photodynamic therapy (PDT), used for cancer treatment, is also an alternative method for eradication of drug-resistant bacteria. This method utilizes a nontoxic light-activated dye, called a photosensitizer, and visible light to produce reactive oxygen species that lead to bacterial cell death. The purpose of this study was to investigate the bactericidal effect of PDT using lanthanide derivatives of meso-tetra(N-methyl-4-pyridyl)porphine against Staphylococcus aureusstrains. The new photosensitizers appeared to be photodynamically ineffective. No enhancement of antistaphylococcal activity of TMPyP was observed after the conjugation of the porphyrin with lanthanide ions. Additionally, a significant difference in the susceptibility of two bacterial strains to unmodified TMPyP was observed.
2

Tritolylporphyrin dimer as a new potent hydrophobic sensitizer for photodynamic therapy of melanoma

86%
Drzewiecka A., Urbanska K., Matuszak Z., Pineiro M., Arnaut L. G., Habdas J., Ratuszna A., Stochel G.
Acta Biochimica Polonica
|
2001
|
tom 48
|
nr 1
We report the synthesis, photochemical and photophysical properties and preliminary studies on biological effect of a new tritolylporphyrin dimer (T-D). Absorption and emis­sion properties of T-D suggest its possible use in photodynamic therapy. T-D is capable of singlet oxygen production with 0.8 quantum yield. It also has a high photostability. The photodynamic properties of the dimer were examined following the growth of SKMEL 188 (human melanoma) cells irradiated with red light (cut off < 630 nm). The surviving frac­tion of the cells decreased about 3-fold (us. non-irradiated cells) for an 81 J/cm dose. Our results suggest that tritolylporphyrine dimer T-D may be an interesting hydrophobic sensitizer for photodynamic therapy.
3

Application of electrophoretic methods for detection of protein-porphyrin complexes

86%
Kowalska A., Kwiek P., Milosz E., Gondek G., Romiszewska A., Graczyk A., Podhajska A. J.
Acta Biochimica Polonica
|
2003
|
tom 50
|
nr 4
Simple methods for detection and isolation of protein-porphyrin complexes were elaborated in our laboratory. They are based on the separation of protein-porphyrin complexes in native polyacrylamide gel and measurement of their fluorescence, with the use of two detection systems: the commercially available Gel Doc™ 2000 system, and a system specially designed for the purpose of these investigations, concerning protein-porphyrin interactions. The fluorescent complexes can be electro-trans­ferred from the gel onto PVDF membrane, eluted and analyzed in order to identify the protein interacting with porphyrins.
4
Content available remote

Light pulse induces ALA-S gene expression in the rat Harderian gland

72%
Djeridane Y., Lyoumi S., Puy H., Touitou Y.
Journal of Physiology and Pharmacology
|
2010
|
tom 61
|
nr 1
115-117
The rodent Harderian glands (HGs) are large paired orbital organs with highest porphyrinogenic rates. We have previously shown that continuous light exposure abolished the day/night variations of the -aminolevulinate synthase (ALA-S; the rate-limiting enzyme for porphyrin biosynthesis) gene expression observed under standard light: dark cycles (LD 12:12) in the rat HGs. This study was designed to examine whether the ALA-S changes were actually associated directly with light. The response of ferrochelatase (enzyme that converts protoporphyrin IX into heme) to light was also examined. Male Wistar rats were acclimatized to light: dark cycles regimen of 12:12 for 2 weeks. At the end of the 2 weeks, a 1 h-light pulse was applied in the middle of the dark phase. Animals were sacrificed immediately after the end of the light pulse. HGs were collected and stored at -80°C until processed for quantitative RT-PCR. A 1 h-light pulse applied during mid-dark caused a significant increase of ALA-S gene expression (3-fold higher than in controls), whereas it was without effect on ferrochelatase gene expression. Our results suggest that light per se may regulate ALA-S gene expression in the rat HGs, and reveal that the ALA-S gene expression, and so heme biosynthesis, is under a photodynamic control.
5

Tetrabromobenzene induced hepatotoxicity in rats following repeated exposure

72%
Frydrych B., Czerski J., Szymanska J. A.
Bromatologia i Chemia Toksykologiczna
|
2002
|
tom 35
|
nr 3
231-239
The aim of the present study was to investigate the influence of tetrabromobenzene after 28 days administration on biochemical indicators. The increase in relative liver mass as well as changes in the levels of cytochromes P-450 were observed. Porphyrins excreted in urine does not indicate strong porphyrogenic effect. No statistically significant changes were detected in other indicators of toxicity (MDA, GSH, ALT, rGT).
6

Bactericidal effect of photodynamic therapy against methicillin-resistant Staphylococcus aureus strain with the use of various porphyrin photosensitizers

72%
Grinholc M., Szramka B., Olender K., Graczyk A.
Acta Biochimica Polonica
|
2007
|
tom 54
|
nr 3
Photodynamic therapy (PDT) is based on photosensitizers activated by light of appropriate wavelength. Their activation leads to generation of singlet oxygen and free radicals responsible for the cytotoxic effect. The aim of this project was to compare the bactericidal effect of PDT using different porphyrin photosensitizers against a methicillin-resistant Staphylococcus aureus strain. Exogenous sensitizers (protoporphyrin IX and newly synthesized derivative, protoporphyrin diarginate) induced a 3 log10-unit reduction in bacterial viable counts. With the use of endogenous, ALA-induced porphyrins, a 1.6 log10-unit reduction was obtained. The sensitizers tested executed their antibacterial activity with no essential change in the antibiotic resistance pattern of the studied strain.
7

The incorporation of various porphyrins into blood cells measured via flow cytometry, absorption and emission spectroscopy

72%
Ion R. M., Planner A., Wiktorowicz K., Frackowiak D.
Acta Biochimica Polonica
|
1998
|
tom 45
|
nr 3
The incorporation of the five following porphyrins: meso-tetra(4-phenyl)porphyrin (TPP); meso-tetra(4-sulfonato-phenyl)porphyrin (TPPS4); meso-tetra(4-naphthyl)porphyrin (TNP); tri-sulfo-tetra-phenyl porphyrin (TPPS3) and tetra-sulfonato-naphthyl porphyrin (TNPS4) into human blood cells was investigated using flow cytometry, and absorption and emission spectroscopy. The percentage of stained cells, measured in a fluorescence cytometer, provided information on the efficiency of incorporation of fluorescent dye molecules into different types of cells. The yield of the incorporation of a dye was dependent on the type of dye and the solvent used for cell incubation. The degree of dye aggregation and ionization varied with the incubation medium, but dye molecules incorporated into cells seemed to be restricted to those in the monomeric state, exhibiting similar fluorescence yield. Of the three sulfonated porphyrins investigated only TPPS4 was efficiently incorporated into leukocytes. In the incubation solvent, this dye was in monomeric and neutral form. TPPS3 which was also in monomeric form, practically was not incorporated into cells. TPP and TNP dissolved in 5% aqueous dimethyl sulfoxide were present mostly in aggregated forms but they penetrated the cells with high efficiency. The results obtained seem to indicate that porphyrins are promising candidates for application in phytodynamic therapy.
8

Concentration of porphyrins in rat liver and kidneys repeated administration of hexabromobenzene and tetrabromobisphenol-A

72%
Frydrych B., Szymanska J. A., Swiderska-Comer A.
Polish Journal of Environmental Studies
|
2006
|
tom 15
|
nr 4
The aim of this study was to complete research on the porphyrogenic effect of hexabrombenzene (HBB) and tetrabromobisphenol-A (TBBP-A). Experiments were performed on female Wistar rats. The examined compounds were administered in sunflower oil intragastrically in 3 doses. The determination of porphyrins in tissues was carried out by means of high-performance liquid chromatography. Repeated HBB administration caused a 3-8 times increase of total concentration of high carboxylated porphyrins (octa- and heptacarboxyporphyrins). The concentrations of these porphyrins were significantly lower in the liver of rats exposed to tbbp-a. However, in the kidneys significant alterations in porphyrins concentrations concerned only HBB.
9

Porfirynuria w przewleklych chorobach watroby

58%
Goljan J.
Acta Biologica et Medica
|
1992
|
tom 19
103-114
10

Photodynamic effects of two water soluble porphyrins evaluated on human malignant melanoma cells in vitro

58%
Szurko A., Kramer-Marek G., Widel M., Ratuszna A., Habdas J., Kus P.
Acta Biochimica Polonica
|
2003
|
tom 50
|
nr 4
Two water soluble porphyrins: meso-tetra-4-N-methylpyridyl-porphyrin iodide (P1) and 5,10-di-(4-acetamidophenyl)-15,20-di-(4-N-methylpyridyl) porphyrin (P2) were synthesised and evaluated in respect to their photochemical and photophysical properties as well as biological activity. Cytotoxic and phototoxic effects were evaluated in human malignant melanoma Me45 line using clonogenic assay, cytological study of micronuclei, apoptosis and necrosis frequency and inhibition of growth of megacolonies. Both porphyrins were characterised by high UV and low visible light absorptions. Dark toxicity measured on the basis of the clonogenic assay and inhibition of megacolony growth area indicated that P1 was non-toxic at concentrations up to 50 ug/ml (42.14 uM) and P2 at concentrations up to 20 ug/ml (16.86 uM). The photodynamic effect induced by red light above 630 nm indicated that both porphyrins were able to inhibit growth of melanoma megacolonies at non-toxic concentrations. Cytologic examination showed that the predominant mode of cell death was necrosis.
11

Szlachetne kamienie

44%
Syga P.
Kwietnik
|
2006
|
nr 11
40-42
12

Metalloporphyrins in recent sediments of the Baltic Sea

44%
Kowalewska G.
Oceanologia
|
1995
|
tom 37
|
nr 1
Pierwsza strona wyników Pięć stron wyników wstecz Poprzednia strona wyników Strona / 1 Następna strona wyników Pięć stron wyników wprzód Ostatnia strona wyników
JavaScript jest wyłączony w Twojej przeglądarce internetowej. Włącz go, a następnie odśwież stronę, aby móc w pełni z niej korzystać.