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Photochemistry and Photobiology

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https://www.readbyqxmd.com/read/28767143/uva%C3%B9-induced-dna-damage-and-apoptosis-in-red-blood-cells-of-the-african-catfish-clarias-gariepinus
#1
Alaa El-Din Hamid Sayed
Ultraviolet-A light (UVA) -induced DNA damage and repair in red blood cells to investigate the sensitivity of African catfish to UVA exposure is reported. Fishes were irradiated with various doses of UVA light (15, 30, and 60 min/day for 3 days). Morphological and nuclear abnormalities in red blood cells were observed in the fish exposed to UVA compared with controls. Morphological alterations such as acanthocytes, crenated cells, swollen cells, teardrop-like cells, hemolyzed cells, and sickle cells were observed...
August 2, 2017: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/28767126/photocrosslinking-of-polyglycidol-and-its-derivative-route-to-thermoresponsive-hydrogels
#2
Alicja Utrata-Wesołek, Iwona Żymełka-Miara, Agnieszka Kowalczuk, Barbara Trzebicka, Andrzej Dworak
Hydrogels of biologically well-tolerated, high-molar-mass polyglycidol and its thermoresponsive derivative poly(glycidol-co-ethyl glycidyl carbamate) have been obtained by direct UV crosslinking in the solid state. Polymers with molar masses up to 1.45 x 10(6) g/mol were crosslinked in the presence of benzophenone or (4-benzoylbenzyl)trimethylammonium chloride as photosensitizers. The photosensitizer concentration was varied from 2 to 10 wt%. The influence of polymer composition and photosensitizer type and amount on the crosslinking efficiency, swelling and temperature behavior of the obtained hydrogels was investigated...
August 2, 2017: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/28763105/physiological-doses-of-red-light-induce-il-4-release-in-co-cultures-between-human-keratinocytes-and-immune-cells
#3
Cheryl Leong, Paul L Bigliardi, Gopu Sriram, Bijin Veonice Au, John Connolly, Mei Bigliardi-Qi
Phototherapy is routinely used for the treatment of various skin conditions and targeted therapy of superficial cancers. However, the molecular mechanisms behind their biological effects and the need for efficacy enhancing photosensitizers are not well addressed. Particularly, not much is known about the inherent effect of light from the visible spectrum on cytokine release and its downstream effects in keratinocytes and immune cells located in skin and therefore exposed to light. To address this, we delivered calibrated doses of well-defined light qualities (380 to 660 nm) to co-cultures of human keratinocytes and macrophage/dendritic cells in the absence or presence of the commonly used photosensitizer 8-methoxypsoralen (8-MOP)...
August 1, 2017: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/28763104/led-phototherapy-with-gelatin-sponge-promotes-wound-healing-in-mice
#4
Heng Zhang, Shupeng Liu, Xiangfei Yang, Na Chen, Fufei Pang, Zhenyi Chen, Tingyun Wang, Jianshe Zhou, Fuji Ren, Xiaoyin Xu, Taihao Li
Tiny but highly efficient, a light emitting diode (LED) can power a therapy device, such as a phototherapy device, and, at the same time, decrease the device's size requirements. In this study, a LED phototherapy device was designed to investigate the possible impact on wound healing using a mouse model and a cell line exposed to red and blue light. To enhance wound phototherapy, a gelatin sponge was fabricated. Results showed that the red and blue lights promoted cell growth and wound healing, while the blue light with a gelatin sponge protected the wound from infection in the early stages of wound healing...
August 1, 2017: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/28763102/resistance-to-hydrogen-peroxide-highlights-gymnodinium-catenatum-dinophyceae-sensitivity-to-geomagnetic-activity
#5
Paulo Vale
The chain-forming dinoflagellate Gymnodinium catenatum was exposed to hydrogen peroxide. Microscopical examination revealed striking dose-response alterations in chain formation above 245 μM: singlets replaced the dominance of long chain formations. These observations were valid for cells acclimated to halogen light. Under fluorescent light, cells were more resistant to modifications in chain length after H2 O2 exposure. Growth along 9-hour in the presence of extracelular H2 O2 followed an hormesis response in both light regimes...
August 1, 2017: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/28756616/parp-1-par-activity-in-cultured-human-lens-epithelial-cells-exposed-to-two-levels-of-uvb-light
#6
Caroline S Cencer, Shravan K Chintala, Tenira J Townsend, Daniel P Feldmann, Mirna A Awrow, Nahrain A Putris, Mason E Geno, Maria G Donovan, Frank J Giblin
This study investigated poly (ADP-ribose) polymerase-1 (PARP-1) activation in cultured human lens epithelial cells exposed to two levels of UVB light (312 nm peak wavelength), 0.014 and 0.14 J/cm(2) ("low" and "high" dose, respectively). At the low dose, PARP-1 and poly (ADP-ribose) (PAR) polymers acted to repair DNA strand breaks rapidly with no subsequent major effects on either cell morphology or viability. However, following the high UVB dose, there was a dramatic second phase of PARP-1 activation, 90 min later, which included a sudden reappearance of DNA strand breaks, bursts of reactive oxygen species (ROS) formation both within the mitochondria and nucleus, a translocation of PAR from the nucleus to the mitochondria, and an ultimate 70% loss of cell viability occurring after 24 hrs...
July 30, 2017: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/28746749/high-throughput-transcriptome-sequencing-reveals-the-role-of-anthocyanin-metabolism-in-begonia-semperflorens-under-high-light-stress
#7
Jiawan Wang, Meili Guo, Yonghua Li, Ronghua Wu, Kaiming Zhang
Begonia semperflorens is an ornamental perennial herb. The leaves of B. semperflorens turn red under increased light, which increases the ornamental value of the plant. The colour of the leaves is determined by anthocyanin metabolism. In B. semperflorens leaves, anthocyanin metabolism is sensitive to external environmental conditions such as temperature, light, and hormone levels. To explore this process in detail and to assess gene expression under high light stress, transcriptome analysis was performed by RNA sequencing using the sequencing-by-synthesis method...
July 26, 2017: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/28746728/analysis-of-the-electronic-structure-of-the-special-pair-of-a-bacterial-photosynthetic-reaction-center-by-13-c-photochemically-induced-dynamic-nuclear-polarization-magic-angle-spinning-nmr-using-a-double-quantum-axis
#8
Marija Najdanova, Daniel Gräsing, A Alia, Jörg Matysik
The origin of the functional symmetry break in bacterial photosynthesis challenges since several decades. Although structurally very similar, the two branches of cofactors in the reaction center (RC) protein complex act very differently. Upon photochemical excitation, an electron is transported along one branch, while the other remains inactive. Photochemically induced dynamic nuclear polarization (photo-CIDNP) magic-angle spinning (MAS) (13) C NMR revealed that the two bacteriochlorophyll cofactors forming the "Special Pair" donor dimer are already well distinguished in the electronic ground-state...
July 26, 2017: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/28741707/photophysical-and-photochemical-properties-of-naturally-cccurring-normelinonine-f-and-melinonine-f-alkaloids-and-structurally-related-n-2-and-or-n-9-methyl-%C3%AE-carboline-derivatives
#9
Federico A O Rasse-Suriani, Fernando S García-Einschlag, Matías Rafti, Tobías Schmidt De León, Pedro M David Gara, Rosa Erra-Balsells, Franco M Cabrerizo
In the present work, we have synthesized and fully characterized the photophysical and photochemical properties of a selected group of N-methyl-β-carboline derivatives (9-methyl-β-carbolines and iodine salts of 2-methyl- and 2,9-dimethyl-β-carbolinium) in aqueous solutions, in the pH-range 4.0 - 14.5. Moreover, despite the quite extensive studies reported in the literature regarding the overall photophysical behaviour of N-unsubstituted βCs, this work constitutes the first full and unambiguous characterization of anionic species of N-unsubstituted βCs (norharmane, harmane and harmine), present in aqueous solution under highly alkaline conditions (pH > 13...
July 25, 2017: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/28722754/-31-p-nmr-evidence-for-peroxide-intermediates-in-lipid-emulsion-photooxidations-phosphine-substituent-effects-in-trapping
#10
Prabhu P Mohapatra, Callistus O Chiemezie, Arina Kligman, Michele M Kim, Theresa M Busch, Timothy C Zhu, Alexander Greer
Intralipid is a lipid emulsion used in photodynamic therapy (PDT) for its light scattering and tissue-simulating properties. The purpose of this study is to determine whether or not Intralipid undergoes photooxidation, we have carried out an Intralipid peroxide trapping study using a series of phosphines [2'-dicyclohexylphosphino-2,6-dimethoxy-1,1'-biphenyl-3-sulfonate, 3-(diphenylphosphino)benzenesulfonate, triphenylphosphine-3,3',3''-trisulfonate, and triphenylphosphine]. Our new findings are as follows: (i) An oxygen atom is transferred from Intralipid peroxide to the phosphine traps in the dark, after the photooxidation of Intralipid...
July 19, 2017: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/28715145/the-autophagy-receptor-adaptor-p62-is-up-regulated-by-uva-radiation-in-melanocytes-and-in-melanoma-cells
#11
Ashley Sample, Baozhong Zhao, Chunli Wu, Steven Qian, Xianglin Shi, Andrew Aplin, Yu-Ying He
UVA (315-400 nm) is the most abundant in sunlight and is used in indoor tanning beds. However, much remains to be understood about the regulation of the UVA damage response in melanocytes and melanoma. Here we show that UVA, but not the shorter waveband UVB (280-315 nm), up-regulates adaptor protein p62 in an Nrf2- and ROS-dependent manner, suggesting a UVA-specific effect on p62 regulation. UVA-induced p62 up-regulation was inhibited by a mitochondria-targeted antioxidant or Nrf2 knockdown. In addition, p62 knockdown inhibited UVA-induced ROS production and Nrf2 up-regulation...
July 17, 2017: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/28710897/early-life-uv-and-risk-of-basal-and-squamous-cell-carcinoma-in-new-south-wales-australia
#12
Anne Kricker, Marianne Weber, Freddy Sitas, Emily Banks, Bayzidur Rahman, Chris Goumas, Ahsanul Kabir, Verity S Hodgkinson, Cathelijne H van Kemenade, Tim Waterboer, Bruce K Armstrong
Sun exposure is the main cause of squamous (SCC) and basal cell carcinoma (BCC) although pattern and amount differ by cancer type, and sun sensitivity is the major host risk factor. Our study investigated risk factors and residential ambient UV in a population-based sample of Australian 45 and Up Study participants: 916 BCC cases, 433 SCC cases, 1224 controls. Unconditional logistic regression models adjusting for key covariates demonstrated 60% increased BCC risk and 2-fold increased SCC risk with sun sensitivity, and 3- and 4-fold increased risk respectively with solar keratoses...
July 15, 2017: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/28710892/photochemical-reaction-between-1-2-naphthoquinone-and-adenine-in-binary-water-acetonitrile-solutions
#13
Qiaohui Zhou, Yaxiong Wei, Xiang Liu, Lin Chen, Xiaoguo Zhou, Shilin Liu
The photochemical reaction between 1,2-naphthoquinone (NQ) and adenine was investigated using nanosecond time-resolved laser flash photolysis. With photolysis at 355 nm, the lowest triplet state T1 of NQ was produced via intersystem crossing from its singlet excited state. The triplet-triplet absorption of the state contributes three bands of transient spectra at374, 596 and 650 nm, respectively, in pure acetonitrile and binary water-acetonitrile solutions. In the presence of adenine, the observation of A•(+) (at 363nm) and NQ+H • radical (at 343 and 485 nm) indicates a multi-step mechanism of electron transfer process followed by a proton transfer between (3) NQ* and adenine...
July 15, 2017: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/28708285/various-led-wavelengths-affected-myofiber-development-and-satellite-cell-proliferation-of-chick-embryos-via-the-igf-1-signaling-pathway
#14
Yao Wang, Xinjie Bai, Zixu Wang, Jing Cao, Yulan Dong, Yanjun Dong, Yaoxing Chen
An effect of monochromatic light illumination on muscle mass has been discovered in chickens; however, its effect on the development of embryonic muscle remains unclear. Our previous studies demonstrated that monochromatic green light promoted satellite cell proliferation and muscle growth in post-hatching broilers. In this study, we investigated the effects and mechanisms of monochromatic light exposure on muscle development in late-embryogenesis. Seven hundred and fifty (750) fertile broiler eggs were randomly assigned to blue (B-group), green (G-group), red (R-group), white (W-group) lights or darkness (D-group) throughout the incubation period...
July 14, 2017: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/28696576/nad-p-h-and-flavin-autofluorescence-correlation-with-atp-in-rat-livers-with-different-metabolic-steady-state-conditions
#15
Anna C Croce, Andrea Ferrigno, Laura G Di Pasqua, Clarissa Berardo, Giovanni Bottiroli, Mariapia Vairetti
The monitoring of NAD(P)H and flavin autofluorescence (AF) is at the basis of numerous investigations on energy metabolism. Nevertheless, the ability of these AF biomarkers to accurately represent the energy currency, ATP, is poorly explored. Here we focused on the AF/ATP correlation in lean and fatty livers with different steady-state metabolic conditions, achieved after organ isolation, preservation and recovery, in a likely dependence on both liver intrinsic metabolic features and externally induced perturbations...
July 11, 2017: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/28696570/effects-of-combined-lysosomal-and-mitochondrial-photodamage-in-a-non-small-cell-lung-cancer-cell-line-the-role-of-paraptosis
#16
David Kessel, John J Reiners
We previously reported that a low-level of lysosomal photodamage potentiated the phototoxic effect of subsequent mitochondrial photodamage mediated by the benzoporphyrin derivative BPD in murine hepatoma 1c1c7 cells. This was attributed to release of Ca(2+) from damaged lysosomes and a calpain-mediated conversion of the autophagy-related protein ATG5 to a pro-apoptotic fragment. We now report a comparison of these results with those obtained with the human non small-cell lung cancer A549 cell line. A549 cells contained lower levels of ATG5 and were less responsive than 1c1c7 cultures to the PDT combination...
July 11, 2017: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/28608526/clothing-protection-from-uvr-a-new-method-for-assessment
#17
Ryan Gage, William Leung, James Stanley, Anthony Reeder, Michelle Barr, Tim Chambers, Moira Smith, Louise Signal
Clothing modifies ultraviolet radiation exposure from the sun, and has an impact on skin cancer risk and the endogenous synthesis of vitamin D3 . There is no standardized method available for assessing body surface area covered by clothing, which limits generalizability between study findings. We calculated the body cover provided by 38 clothing items using diagrams of body surface area (BSA), adjusting the values to account for differences in BSA by age. Diagrams displaying each clothing item were developed and incorporated into a coverage assessment procedure (CAP)...
June 13, 2017: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/28599356/an-in-vitro-model-for-fibroblast-photoaging-comparing-single-and-repeated-uva-irradiations
#18
Wongnapa Nakyai, Aurasorn Saraphanchotiwitthaya, Celine Viennet, Philippe Humbert, Jarupa Viyoch
The current method for efficient evaluation of anti-photoaging compounds is an in vitro skin culture model using a single ultraviolet A (UVA) irradiation of fibroblasts. However, skin photoaging is caused by repeated exposure to UVA radiation. The objective of this study was to develop an appropriate model for in vitro skin photoaging by comparing the different effects of single (5 J/cm(2) ) and repeated exposures (5 J/cm(2) x 3 times) of fibroblasts to UVA irradiation. Our results demonstrated that a single and repeated exposure to UVA irradiation had different effects on fibroblasts...
June 9, 2017: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/28597944/a-quantum-mechanical-study-of-the-binding-pocket-of-proteorhodopsin-absorption-and-vibrational-spectra-modulated-by-analogue-chromophores
#19
Francesco Buda, Tom Keijer, Srividya Ganapathy, Willem J de Grip
Proteorhodopsin is a light-driven proton pumping membrane protein related to bacteriorhodopsin. It contains an all-trans retinal A1 chromophore covalently bound to a lysine residue via a protonated Schiff base. In this study, we exploited density functional theory (DFT) calculations to investigate the retinal binding pocket in the dark state and after mimicking photoisomerization. The model of the binding pocket is constructed incrementally by adding the residues near the retinal that are necessary to ensure a stable protonated Schiff base...
June 9, 2017: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/28574176/a-photosensitizer-lanthanide-nanoparticle-formulation-that-induces-singlet-oxygen-with-direct-light-excitation-but-not-by-photon-or-x-ray-energy-transfer
#20
Rima Chouikrat, Francis Baros, Jean-Claude André, Régis Vanderesse, Bruno Viana, Anne-Laure Bulin, Christophe Dujardin, Philippe Arnoux, Marc Verelst, Céline Frochot
We report the design and synthesis of europium-doped gadolinium oxysulfide nanoscintillators Gd2 O2 S:Eu(3+) conjugated with two different photosensitizers (PSs): a zinc chlorin (ZnTPC) and a zinc phtalocyanine (ZnPc) by covalent bonding through a layer of N-(3-trimethoxysilylpropyl)diethylenetriamine (TPDA). These conjugates were designed to be activated under X-ray excitation to allow a photodynamic effect, although this desired outcome was not achieved in this study. The monodispersed nanoparticles of ∼70 nm diameter were pegylated to be stabilized in aqueous suspension...
June 2, 2017: Photochemistry and Photobiology
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