Abstract：
:Pyocyanin (PyO-) (1-hydroxy-5-methylphenazine) is a cytotoxic compound secreted by Pseudomonas aeruginosa, an omnipresent bacterium and a human pathogen. We report that visible light illumination in the presence of rose bengal, or riboflavin, in aerated solutions (pH 7.0-7.2) induces irreversible loss of the pigment's characteristic absorption band at 690 nm, indicating its oxidation. This photobleaching was paralleled by generation of a multiline Electron Paramagnetic Resonance (EPR) spectrum attributed to a PyO(-)-derived radical. The reaction was dependent on the presence of air, sensitizers and light, was inhibited by sodium azide and was unaffected by ethanol. This suggests that PyO- was oxidized largely via singlet oxygen and that hydroxyl radicals were not involved. The photochemically modified pigment was less efficient in oxidizing NAD(P)H and generated less superoxide (by approximately 50%) than the intact PyO-, indicating its partial inactivation. 1-Methoxy-5-methylphenazine, a PyO- analog in which the -O- moiety was replaced by the methoxy group (-OMe), was resistant to oxidation, suggesting that oxidation of PyO- involves its phenolate moiety. These results also suggest that photosensitization could be a potentially useful method for inactivation of PyO- and, possibly, detoxification of superficial wounds (skin, eye) infected with P. aeruginosa.
journal_name
Photochem Photobioljournal_title
Photochemistry and photobiologyauthors
Reszka KJ,Denning GM,Britigan BEdoi
10.1562/2005-07-29-RA-626subject
Has Abstractpub_date
2006-03-01 00:00:00pages
466-73issue
2eissn
0031-8655issn
1751-1097pii
2005-07-29-RA-626Rjournal_volume
82pub_type
杂志文章abstract：:Pharmacological therapy is widely used in the treatment of muscle injuries. On the other hand, low-level laser therapy (LLLT) arises as a promising nonpharmacological treatment. The aim of this study was to analyze the effects of sodium diclofenac (topical application) and LLLT on morphological aspects and gene expres...
journal_title：Photochemistry and photobiology
pub_type： 杂志文章
doi：10.1111/j.1751-1097.2012.01232.x
更新日期：2013-03-01 00:00:00
abstract：:Blue visible light damage to retinal pigment epithelial cells occurs through a photooxidative mechanism and the resultant damage is hypothesized to induce or exacerbate age-related macular degeneration. The purpose of the present study was to identify changes in the cell growth and the expression of hepatocyte growth ...
journal_title：Photochemistry and photobiology
pub_type： 杂志文章
doi：10.1562/2006-04-19-RA-880
更新日期：2006-09-01 00:00:00
abstract：:Color variants of Ca2+ -regulated photoprotein obelin were shown to be an important tool for dual-analyte binding assay. To provide site-directed conjugation with biospecific molecules, several obelin color mutants carrying unique cysteine residues were obtained and characterized for their novel properties. A pair of ...
journal_title：Photochemistry and photobiology
pub_type： 杂志文章,评审
doi：10.1111/php.12712
更新日期：2017-03-01 00:00:00
abstract：:The azide ion is a strong physical quencher of singlet molecular oxygen (1O2) and is frequently employed to show involvement of 1O2 in oxidation processes. Rate constants (k(q)) for the quenching of 1O2 by azide are routinely used as standards to calculate k(q) values for quenching by other substrates. We have measure...
journal_title：Photochemistry and photobiology
pub_type： 杂志文章
doi：10.1562/0031-8655(2001)074<0760:qosmoo>2.0.co;2
更新日期：2001-12-01 00:00:00
abstract：:Photodynamic therapy (PDT) is frequently accompanied by induction of systemic immunosuppression. Photochemical mechanisms underlying this effect are not completely understood. Here, we demonstrate the immunosuppressive activity of photooxidation products of protoporphyrin IX dimethyl ester (PPIX) in a murine model of ...
journal_title：Photochemistry and photobiology
pub_type： 杂志文章
doi：10.1562/2005-04-26-RA-500
更新日期：2005-11-01 00:00:00
abstract：:Unlike the enchanting yellow-green flashes of light produced on warm summer evenings by Photinus pyralis, the most common firefly species in North America, the orange lights of Photinus scintillans are infrequently observed. These Photinus species, and likely all bioluminescent beetles, use the same substrates beetle ...
journal_title：Photochemistry and photobiology
pub_type： 杂志文章
doi：10.1111/php.12671
更新日期：2017-03-01 00:00:00
abstract：:Several antibacterial halogenated salicylanilides, including 3,3',4',5-tetrachlorosalicylanilide (TCSA) and 3,4',5-tribromosalicylanilide (TBSA) are known to cause photoallergy. We have carried out photochemical and spin trapping studies to determine whether free radicals may be involved in the photoallergic response....
journal_title：Photochemistry and photobiology
pub_type： 杂志文章
doi：10.1111/j.1751-1097.1989.tb04162.x
更新日期：1989-09-01 00:00:00
abstract：:People can get oral cancers from UV (290-400 nm) exposures. Besides high outdoor UV exposures, high indoor UV exposures to oral tissues can occur when consumers use UV-emitting tanning devices to either tan or whiten their teeth. We compared the carcinogenic risks of skin to oral tissue cells after UVB (290-320 nm) ex...
journal_title：Photochemistry and photobiology
pub_type： 杂志文章
doi：10.1111/php.12030
更新日期：2013-05-01 00:00:00
abstract：:The thermodynamics of binding of Me-alpha(-GalNAc, Gal-beta-1-3GalNAc-alpha-O-Me (T-antigen-alpha), Gal-beta-1-3GalNAc and Gal-alpha-1-6Glc (mellibiose) to Artocarpus hirsuta lectin was studied using fluorescence spectroscopy. The binding affinities of the saccharides are in the order Gal-beta-1-3GalNAc-alpha-O-Me > M...
journal_title：Photochemistry and photobiology
pub_type： 杂志文章
doi：10.1562/2006-05-04-RN-892
更新日期：2006-09-01 00:00:00
abstract：:Using information on solar irradiance at different latitudes derived from a radiative transfer model and a detailed in vivo action spectrum for immune suppression in a murine system, we report here calculations of the "biologically effective" irradiance of sunlight for immune suppression. From 40 degrees N to 40 degre...
journal_title：Photochemistry and photobiology
pub_type： 杂志文章
doi：10.1111/j.1751-1097.1990.tb08686.x
更新日期：1990-10-01 00:00:00
abstract：:Photodynamic therapy (PDT) appears as a promising alternative in the treatment of breast cancer since it can be highly effective in curing cancer while preserving normal tissue. However, predicting outcomes in PDT still constitutes a great challenge. One of the parameters that are usually empirically determined is the...
journal_title：Photochemistry and photobiology
pub_type： 杂志文章
doi：10.1111/php.13182
更新日期：2020-05-01 00:00:00
abstract：:An approximate formula for the UV Index (UVI) under cloud-free, unpolluted, low surface albedo conditions is: UVI approximately 12.5mu(o)(2.42)(Omega/300)(-1.23) where mu(o) is the cosine of the solar zenith angle and Omega is the total vertical ozone column (in Dobson Units, DU). The dependence on mu(o) and Omega is ...
journal_title：Photochemistry and photobiology
pub_type： 杂志文章
doi：10.1111/j.1751-1097.2007.00200.x
更新日期：2007-11-01 00:00:00
abstract：:The photodegradation of the S(+)- and R(-)-ketoprofen (KP) enantiomers in the bovine serum albumin matrix was studied by steady-state photolysis with the use of lambda(irr) > 320 nm and transient absorption spectroscopy with lambda(exc) = 355 nm, at 1/1 and 2/1 KP/BSA molar ratios. R(-)-KP was found to be more labile ...
journal_title：Photochemistry and photobiology
pub_type： 杂志文章
doi：10.1562/2005-07-11-RA-608
更新日期：2006-01-01 00:00:00
abstract：:We describe here the development of monoclonal antibodies to the hapten tryptophan-riboflavin, generated by irradiation of a solution of bovine serum albumin in the presence of riboflavin. The specificity of the three obtained monoclonal antibodies, named 1E6, 5H5, 5A8 all belonging to the IgG1 isotype, was assessed b...
journal_title：Photochemistry and photobiology
pub_type： 杂志文章
doi：10.1111/j.1751-1097.1996.tb09628.x
更新日期：1996-06-01 00:00:00
abstract：:All-trans retinoic acid (ATRA) plays essential roles in the normal biological processes and the treatment of cancer and skin diseases. Considering its photosensitive property, many studies have been focused on the photochemistry of ATRA. In this study, we investigated the transient phenomena in the laser flash photoly...
journal_title：Photochemistry and photobiology
pub_type： 杂志文章
doi：10.1111/php.12128
更新日期：2013-09-01 00:00:00
abstract：:We report the preparation of aminopropyl-functionalized magnesium phyllosilicate (Mg-organoclay) conjugated to fluorescein isothiocyanate (FITC) functionality (FITC-organoclay) by one-pot sol-gel synthesis. The physical characteristics of the Mg- and FITC-organoclays were examined by scanning electron microscopy (SEM)...
journal_title：Photochemistry and photobiology
pub_type： 杂志文章
doi：10.1111/j.1751-1097.2009.00701.x
更新日期：2010-05-01 00:00:00
abstract：:Cryptococus gattii is an emergent primary human pathogen that causes meningismus, papilledema, high intracranial pressure and focal involvement of the central nervous system in immunocompetent hosts. Prolonged antifungal therapy is the conventional treatment, but it is highly toxic, selects for resistant strains, cont...
journal_title：Photochemistry and photobiology
pub_type： 杂志文章
doi：10.1111/j.1751-1097.2010.00868.x
更新日期：2011-03-01 00:00:00
abstract：:The chloride effect on the photobleaching process of iodopsin, a chicken red-sensitive cone visual pigment, was studied in detail by time-resolved low-temperature spectroscopy at -40 degrees C to -10 degrees C. Decay-associated difference spectra obtained by kinetic analysis using the singular value decomposition meth...
journal_title：Photochemistry and photobiology
pub_type： 杂志文章
doi：10.1111/j.1751-1097.2008.00332.x
更新日期：2008-07-01 00:00:00
abstract：:The dependence of autofluorescence properties on the metabolic and functional engagement and on the transformation condition was studied on single cells. Normal Galliera rat fibroblasts at low subculture passage (cell strain), at high subculture passage (stabilized cell line), and transformed cell line derived from a ...
journal_title：Photochemistry and photobiology
pub_type： 杂志文章
doi：10.1562/0031-8655(1999)069<0364:dofapo>2.3.co;2
更新日期：1999-03-01 00:00:00
abstract：:Polarized steady-state fluorescence and fluorescence excitation spectra as well as time-resolved fluorescence for B-phycoerythrin (B-PE) from red algae, Porphyridium cruentum, embedded in polyvinyl stretched films were measured. The lifetimes of polarized fluorescence were analyzed using exponential components and fra...
journal_title：Photochemistry and photobiology
pub_type： 杂志文章
doi：
更新日期：2004-01-01 00:00:00
abstract：:Efficient phagocytosis of photoreceptor outer segments (POS) membranes by retinal pigment epithelium (RPE) plays a key role in biological renewal of these highly peroxidizable structures. Here, we tested whether photodynamic treatment, mediated by merocyanine 540 (MC 540), rose Bengal or a zinc-substituted chlorophyll...
journal_title：Photochemistry and photobiology
pub_type： 杂志文章
doi：10.1111/j.1751-1097.2010.00727.x
更新日期：2010-07-01 00:00:00
abstract：:The ultraviolet (UV) component of solar radiation is the driving force of life on earth, but it can cause photoaging and skin cancer. In this study, we investigated the effects of the glucosamine-derivative 2-(N-Acetyl)-L-phenylalanylamido-2-deoxy-β-D-glucose (NAPA) on human primary fibroblasts (FBs) stimulated in vit...
journal_title：Photochemistry and photobiology
pub_type： 杂志文章
doi：10.1111/php.13185
更新日期：2020-01-01 00:00:00
abstract：:We report the spectroscopic properties of fluorescein, x-rhodamine, tetramethyl-rhodamine, attached to single strand, duplex DNA, and to the digestion products by DNAse I. The properties reported include: molar absorptivity, quantum yield, absorbance and fluorescence spectra, fluorescence lifetime, intrinsic lifetime ...
journal_title：Photochemistry and photobiology
pub_type： 杂志文章
doi：10.1111/j.1751-1097.2009.00663.x
更新日期：2010-03-01 00:00:00
abstract：:Plant responses to light spectral quality can be exploited to deliver a range of agronomically desirable end points in protected crops. This can be achieved using plastics with specific spectral properties as crop covers. We have studied the responses of a range of crops to plastics that have either (a) increased tran...
journal_title：Photochemistry and photobiology
pub_type： 杂志文章
doi：10.1562/2004-12-06-RA-392
更新日期：2005-09-01 00:00:00
abstract：:UV rays may cause several degrees of skin damage, which makes sunscreen research necessary. In addition, skin sensitivity shows daily variations, which can interfere in the detection of the efficacy of the filters. Here, we studied the UV-induced erythema in hairless rats at two times of the day (light and darkness) u...
journal_title：Photochemistry and photobiology
pub_type： 杂志文章
doi：10.1111/php.12670
更新日期：2017-03-01 00:00:00
abstract：:A novel type of circadian and photoperiodic control of the cell division cycle was found in photoautotrophic Euglena gracilis. When algae entrained to 24 h light-dark (LD) cycles (14 h L) were transferred to continuous darkness (DD) at the eighth hour of the final LD photoperiod, cell-cycle transition was arrested in ...
journal_title：Photochemistry and photobiology
pub_type： 杂志文章
doi：10.1562/0031-8655(2002)076<0105:cgopoc>2.0.co;2
更新日期：2002-07-01 00:00:00
abstract：:Ultraviolet radiation (UVR) is hazardous to patients with photosensitive skin disorders, such as lupus erythematosus, xeroderma pigmentosum and skin cancer. As such, these patients are advised to minimize their exposure to UVR. Classically, this is accomplished through careful avoidance of sun exposure and artificial ...
journal_title：Photochemistry and photobiology
pub_type： 杂志文章
doi：10.1111/j.1751-1097.2009.00540.x
更新日期：2009-07-01 00:00:00
abstract：:In cultured human keratinocytes, the tumor suppressor p53 acts as a control element in the protective response to UVB radiation and is affected by a variety of factors linked to cellular adhesion and differentiation. Because keratinocytes within the epidermis are not a homogeneous population but differ in their prolif...
journal_title：Photochemistry and photobiology
pub_type： 杂志文章
doi：10.1562/0031-8655(2000)071<0321:pduroh>2.0.co;2
更新日期：2000-03-01 00:00:00
abstract：:Singlet oxygen reacts preferentially with three amino acids in proteins, His, Trp and Met. In order to study the specific molecular events that result from such oxidations, calf alpha-crystallin was photooxidized in the presence of uroporphyrin and the reactions were investigated by high performance liquid chromatogra...
journal_title：Photochemistry and photobiology
pub_type： 杂志文章
doi：10.1111/j.1751-1097.1993.tb02330.x
更新日期：1993-03-01 00:00:00
abstract：:Cis-urocanic acid (UCA), formed in the epidermis by UV irradiation of trans-UCA, has been implicated as a mediator of the immunosuppression induced by UV exposure of the skin. This review covers recent work in which the wavelength dependence of cis-UCA formation, the interaction of UCA isomers with DNA, the effects of...
journal_title：Photochemistry and photobiology
pub_type： 杂志文章,评审
doi：10.1111/j.1751-1097.1995.tb05261.x
更新日期：1995-08-01 00:00:00
