keyword
MENU ▼
Read by QxMD icon Read
search

Photoprotection

keyword
https://www.readbyqxmd.com/read/28218743/vitamin-d-signaling-and-melanoma-role-of-vitamin-d-and-its-receptors-in-melanoma-progression-and-management
#1
REVIEW
Andrzej T Slominski, Anna A Brożyna, Michal A Zmijewski, Wojciech Jóźwicki, Anton M Jetten, Rebecca S Mason, Robert C Tuckey, Craig A Elmets
Ultraviolet B (UVB), in addition to having carcinogenic activity, is required for the production of vitamin D3 (D3) in the skin which supplies >90% of the body's requirement. Vitamin D is activated through hydroxylation by 25-hydroxylases (CYP2R1 or CYP27A1) and 1α-hydroxylase (CYP27B1) to produce 1,25(OH)2D3, or through the action of CYP11A1 to produce mono-di- and trihydroxy-D3 products that can be further modified by CYP27B1, CYP27A1, and CYP24A1. The active forms of D3, in addition to regulating calcium metabolism, exert pleiotropic activities, which include anticarcinogenic and anti-melanoma effects in experimental models, with photoprotection against UVB-induced damage...
February 20, 2017: Laboratory Investigation; a Journal of Technical Methods and Pathology
https://www.readbyqxmd.com/read/28213741/assembly-of-photoactive-orange-carotenoid-protein-from-its-domains-unravels-a-carotenoid-shuttle-mechanism
#2
Marcus Moldenhauer, Nikolai N Sluchanko, David Buhrke, Dmitry V Zlenko, Neslihan N Tavraz, Franz-Josef Schmitt, Peter Hildebrandt, Eugene G Maksimov, Thomas Friedrich
The photoswitchable orange carotenoid protein (OCP) is indispensable for cyanobacterial photoprotection by quenching phycobilisome fluorescence upon photoconversion from the orange OCP(O) to the red OCP(R) form. Cyanobacterial genomes frequently harbor, besides genes for orange carotenoid proteins (OCPs), several genes encoding homologs of OCP's N- or C-terminal domains (NTD, CTD). Unlike the well-studied NTD homologs, called Red Carotenoid Proteins (RCPs), the role of CTD homologs remains elusive. We show how OCP can be reassembled from its functional domains...
February 17, 2017: Photosynthesis Research
https://www.readbyqxmd.com/read/28212650/skin-cancer-knowledge-and-attitudes-in-the-region-of-fez-morocco-a-cross-sectional-study
#3
Awatef Kelati, Hanane Baybay, Mariam Atassi, Samira Elfakir, Salim Gallouj, Mariame Meziane, Fatima Zahra Mernissi
BACKGROUND: The prevalence of skin cancers is constantly increasing in Morocco, and they have gradually become more aggressive due to a significant delay in the diagnosis. Our aim was to assess the levels of awareness and the influencing factors related to skin cancer knowledge in Morocco. METHODS: This cross-sectional study was carried out in Morocco through the medium of a validated questionnaire, which contained several items - demographics, skin cancer knowledge and attitudes towards skin cancer patients- during a period of 1 year (2014)...
February 17, 2017: BMC Dermatology
https://www.readbyqxmd.com/read/28211527/depth-specific-fluctuations-of-gene-expression-and-protein-abundance-modulate-the-photophysiology-in-the-seagrass-posidonia-oceanica
#4
Gabriele Procaccini, Miriam Ruocco, Lázaro Marín-Guirao, Emanuela Dattolo, Christophe Brunet, Daniela D'Esposito, Chiara Lauritano, Silvia Mazzuca, Ilia Anna Serra, Letizia Bernardo, Amalia Piro, Sven Beer, Mats Björk, Martin Gullström, Pimchanok Buapet, Lina M Rasmusson, Paulo Felisberto, Sylvie Gobert, John W Runcie, João Silva, Irene Olivé, Monya M Costa, Isabel Barrote, Rui Santos
Here we present the results of a multiple organizational level analysis conceived to identify acclimative/adaptive strategies exhibited by the seagrass Posidonia oceanica to the daily fluctuations in the light environment, at contrasting depths. We assessed changes in photophysiological parameters, leaf respiration, pigments, and protein and mRNA expression levels. The results show that the diel oscillations of P. oceanica photophysiological and respiratory responses were related to transcripts and proteins expression of the genes involved in those processes and that there was a response asynchrony between shallow and deep plants probably caused by the strong differences in the light environment...
February 17, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28210627/hyperforin-hp-%C3%AE-cyclodextrin-enhances-mechanosensitive-ca-2-signaling-in-hacat-keratinocytes-and-in-atopic-skin-ex-vivo-which-accelerates-wound-healing
#5
Hiroya Takada, Jun Yonekawa, Masami Matsumoto, Kishio Furuya, Masahiro Sokabe
Cutaneous wound healing is accelerated by mechanical stretching, and treatment with hyperforin, a major component of a traditional herbal medicine and a known TRPC6 activator, further enhances the acceleration. We recently revealed that this was due to the enhancement of ATP-Ca(2+) signaling in keratinocytes by hyperforin treatment. However, the low aqueous solubility and easy photodegradation impede the topical application of hyperforin for therapeutic purposes. We designed a compound hydroxypropyl-β-cyclodextrin- (HP-β-CD-) tetracapped hyperforin, which had increased aqueous solubility and improved photoprotection...
2017: BioMed Research International
https://www.readbyqxmd.com/read/28209050/-active-photoprotection-sunscreens-with-dna-repair-enzymes-a-review-of-the-literature
#6
Matteo Megna, Serena Lembo, Nicola Balato, Giuseppe Monfrecola
Ultraviolet (UV) radiation exerts different harmful effects on human health, being the main etiological agents of certain skin cancers and photoaging. In this context, photoprotection, intended as a set of measures adopted to limit and prevent the effects of UV radiation, plays a critical role in avoiding undesired sunlight outcomes. Traditional sunscreens represent a widely used photoprotective approach, even if they exert a "passive photoprotection" and are not effective once damage to skin cells has been generated after sun exposure...
February 16, 2017: Giornale Italiano di Dermatologia e Venereologia: Organo Ufficiale, Società Italiana di Dermatologia e Sifilografia
https://www.readbyqxmd.com/read/28199904/cyclic-electron-flow-may-provide-some-protection-against-psii-photoinhibition-in-rice-oryza-sativa-l-leaves-under-heat-stress
#7
Jemaa Essemine, Yi Xiao, Mingnan Qu, Hualing Mi, Xin-Guang Zhu
Previously we have shown that a quick down-regulation in PSI activity compares to that of PSII following short-term heat stress for two rice groups including C4023 and Q4149, studied herein. These accessions were identified to have different natural capacities in driving cyclic electron flow (CEF) around PSI; i.e., low CEF (lcef) and high CEF (hcef) for C4023 and Q4149, respectively. The aim of this study was to investigate whether these two lines have different mechanisms of protecting photosystem II from photodamage under heat stress...
January 30, 2017: Journal of Plant Physiology
https://www.readbyqxmd.com/read/28195487/sequential-proton-coupled-electron-transfer-mediates-excited-state-deactivation-of-a-eumelanin-building-block
#8
Juan J Nogueira, Alice Corani, Amal El Nahhas, Alessandro Pezzella, Marco d'Ischia, Leticia Gonzalez, Villy Sundstrom
Skin photoprotection is commonly believed to rely on the photochemistry of 5,6-dihydroxyindole (DHI)- and 5,6-dihydroxyindole-2-carboxylic acid (DHICA)-based eumelanin building blocks. Attempts to elucidate the underlying excited-state relaxation mechanisms have been partly unsuccessful due to the marked instability to oxidation. Herein, we report a study of the excited-state deactivation of DHI using steady-state and time-resolved fluorescence accompanied by high-level quantum chemistry calculations including solvent effects...
February 14, 2017: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/28194795/diversity-of-winter-photoinhibitory-responses-a-case-study-in-co-occurring-lichens-mosses-herbs-and-woody-plants-from-subalpine-environments
#9
Fátima Míguez, Beatriz Fernández-Marín, José-María Becerril, José-Ignacio García-Plazaola
Winter evergreens living in mountainous areas have to withstand a harsh combination of high light levels and low temperatures in wintertime. In response, evergreens can activate a photoprotective process that consists of the down-regulation of photosynthetic efficiency, referred to as winter photoinhibition (WPI). WPI has been studied mainly in woody evergreens and crops even when, in many instances, other functional groups such as lichens or bryophytes dominate in alpine and boreal habitats. Thus, we aimed to (1) assess the occurrence of WPI within overwintering evergreens comprising woody species, herbs, mosses and lichens; (2) compare the recovery kinetics among those groups; and (3) clarify the role of thylakoid proteins and pigments in both processes: WPI and recovery...
February 14, 2017: Physiologia Plantarum
https://www.readbyqxmd.com/read/28192168/novel-benzophenone-3-derivatives-with-promising-potential-as-uv-filters-relationship-between-structure-photoprotective-potential-and-phototoxicity
#10
María Teresa Páez González, Fernando Fumagalli, Carolina Gomes Benevenuto, Flavio da Silva Emery, Lorena Rigo Gaspar
Benzophenone-3 (BP-3) is a UV filter with absorption at the UVB and UVA wavelengths which has not been extensively studied in experiments involving its absorbing effects and toxicity. We synthetized four BP-3 derivatives and characterized their photoprotective potential by UV absorption and photodegradation, their phototoxicity potential by 3T3 Neutral Red Uptake (3T3 NRU PT) and their photoreactivity by the reactive oxygen species (ROS) assay. The UV absorption, photodegradation, phototoxicity and photoreactivity of the four BP-3 derivatives (BP-3 carbonate, BP-3 carbazole, BP-3 phenylamine and BP-3 methoxy-phenylamine) were evaluated and compared to those of BP-3...
February 10, 2017: European Journal of Pharmaceutical Sciences
https://www.readbyqxmd.com/read/28189068/passiflora-tarminiana-fruits-reduce-uvb-induced-photoaging-in-human-skin-fibroblasts
#11
Karent Bravo, Luisa Duque, Federico Ferreres, Diego A Moreno, Edison Osorio
Skin aging is a complex process that is strongly affected by UV radiation, which stimulates the production of reactive oxygen species (ROS) in the epidermis and dermis and subsequently causes skin damage. Among the major consequences are increased collagen degradation and reduced collagen synthesis. Previous reports have demonstrated the beneficial effects of polyphenols for healthy skin. Passiflora tarminiana Coppens & V.E. Barney, a species of the Passifloraceae family, is widely distributed in South America and is rich in flavonoids...
February 3, 2017: Journal of Photochemistry and Photobiology. B, Biology
https://www.readbyqxmd.com/read/28188782/lipid-and-carotenoid-cooperation-driven-adaptation-to-light-and-temperature-stress-in-synechocystis-sp-pcc6803
#12
Tomas Zakar, Eva Herman, Sindhujaa Vajravel, Laszlo Kovacs, Jana Knoppová, Josef Komenda, Ildiko Domonkos, Mihaly Kis, Zoltan Gombos, Hajnalka Laczko-Dobos
Polyunsaturated lipids are important components of photosynthetic membranes. Xanthophylls are the main photoprotective agents, can assist in protection against light stress, and are crucial in the recovery from photoinhibition. We generated the xanthophyll- and polyunsaturated lipid-deficient ROAD mutant of Synechocystis sp. PCC6803 (Synechocystis) in order to study the little-known cooperative effects of lipids and carotenoids (Cars). Electron microscopic investigations confirmed that in the absence of xanthophylls the S-layer of the cellular envelope is missing...
February 7, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/28188781/the-cyanobacterial-fluorescence-recovery-protein-has-two-distinct-activities-orange-carotenoid-protein-amino-acids-involved-in-frp-interaction
#13
Adrien Thurotte, Céline Bourcier de Carbon, Adjélé Wilson, Léa Talbot, Sandrine Cot, Rocio López-Igual, Diana Kirilovsky
To deal with fluctuating light condition, cyanobacteria have developed a photoprotective mechanism which, under high light conditions, decreases the energy arriving at the photochemical centers. It relies on a photoswitch, the Orange Carotenoid Protein (OCP). Once photoactivated, OCP binds to the light harvesting antenna, the phycobilisome (PBS), and triggers the thermal dissipation of the excess energy absorbed. Deactivation of the photoprotective mechanism requires the intervention of a third partner, the Fluorescence Recovery Protein (FRP)...
February 7, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/28182317/impact-of-light-intensity-and-quality-on-chromatophore-and-nuclear-gene-expression-in-paulinella-chromatophora-an-amoeba-with-nascent-photosynthetic-organelles
#14
Ru Zhang, Eva C M Nowack, Dana C Price, Debashish Bhattacharya, Arthur R Grossman
Plastid evolution has been attributed to a single primary endosymbiotic event that occurred ~1.6 BYA in which a cyanobacterium was engulfed and retained by a eukaryotic cell, although early steps in plastid integration are poorly understood. The photosynthetic amoeba Paulinella chromatophora represents a unique model to study plastid evolution because it contains cyanobacterium-derived photosynthetic organelles termed "chromatophores" that originated relatively recently (0.06-0.14 BYA). The chromatophore genome is ~1/3 the size of the genome of closely related cyanobacteria, but 10-fold larger than most plastid genomes...
February 9, 2017: Plant Journal: for Cell and Molecular Biology
https://www.readbyqxmd.com/read/28181477/eumelanin-releasing-spongy-like-hydrogels-for-skin-re-epithelialization-purposes
#15
Lucília Pereira da Silva, Sílvia Oliveira, Rogério Pirraco, Tírcia Santos, Rui Reis, Alexandra Marques, Vitor Correlo
Melanin function in the skin has been associated to pigmentation but other properties such as electrical conductance, photoprotection, antioxidant and antimicrobial activity, have also been recognized. Nonetheless, the use of melanin in a skin wound healing context was never considered. In this sense, eumelanin particles with a typical round and nano-sized morphology and electrical conductivity of 2.09x10-8S·cm-1 were extracted from the ink of Sepia officinalis. The ability of primary human keratinocytes to phagocyte eumelanin, which was then accumulated in cytosolic vesicles and nuclei surroundings, was demonstrated...
February 9, 2017: Biomedical Materials
https://www.readbyqxmd.com/read/28176042/acclimation-of-shade-tolerant-and-light-resistant-tradescantia-species-to-growth-light-chlorophyll-a-fluorescence-electron-transport-and-xanthophyll-content
#16
Vladimir I Mishanin, Boris V Trubitsin, Svetlana V Patsaeva, Vasily V Ptushenko, Alexei E Solovchenko, Alexander N Tikhonov
In this study, we have compared the photosynthetic characteristics of two contrasting species of Tradescantia plants, T. fluminensis (shade-tolerant species), and T. sillamontana (light-resistant species), grown under the low light (LL, 50-125 µmol photons m(-2) s(-1)) or high light (HL, 875-1000 µmol photons m(-2) s(-1)) conditions during their entire growth period. For monitoring the functional state of photosynthetic apparatus (PSA), we measured chlorophyll (Chl) a emission fluorescence spectra and kinetics of light-induced changes in the heights of fluorescence peaks at 685 and 740 nm (F 685 and F 740)...
February 8, 2017: Photosynthesis Research
https://www.readbyqxmd.com/read/28174567/in-vivo-microscale-measurements-of-light-and-photosynthesis-during-coral-bleaching-evidence-for-the-optical-feedback-loop
#17
Daniel Wangpraseurt, Jacob B Holm, Anthony W D Larkum, Mathieu Pernice, Peter J Ralph, David J Suggett, Michael Kühl
Climate change-related coral bleaching, i.e., the visible loss of zooxanthellae from the coral host, is increasing in frequency and extent and presents a major threat to coral reefs globally. Coral bleaching has been proposed to involve accelerating light stress of their microalgal endosymbionts via a positive feedback loop of photodamage, symbiont expulsion and excess in vivo light exposure. To test this hypothesis, we used light and O2 microsensors to characterize in vivo light exposure and photosynthesis of Symbiodinium during a thermal stress experiment...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28172898/p184-photoprotective-behaviours-in-inflammatory-bowel-disease-patients-on-azathioprine-and-tnf-%C3%AE-inhibitors
#18
C Gallagher, A Ridge, A M Tobin, D Kevans, D McNamara
No abstract text is available yet for this article.
February 1, 2017: Journal of Crohn's & Colitis
https://www.readbyqxmd.com/read/28167950/small-one-helix-proteins-are-essential-for-photosynthesis-in-arabidopsis
#19
Jochen Beck, Jens N Lohscheider, Susanne Albert, Ulrica Andersson, Kurt W Mendgen, Marc C Rojas-Stütz, Iwona Adamska, Dietmar Funck
The extended superfamily of chlorophyll a/b binding proteins comprises the Light-Harvesting Complex Proteins (LHCs), the Early Light-Induced Proteins (ELIPs) and the Photosystem II Subunit S (PSBS). The proteins of the ELIP family were proposed to function in photoprotection or assembly of thylakoid pigment-protein complexes and are further divided into subgroups with one to three transmembrane helices. Two small One-Helix Proteins (OHPs) are expressed constitutively in green plant tissues and their levels increase in response to light stress...
2017: Frontiers in Plant Science
https://www.readbyqxmd.com/read/28167040/induction-of-cyclic-electron-flow-around-photosystem-i-during-heat-stress-in-grape-leaves
#20
Yongjiang Sun, Qingwei Geng, Yuanpeng Du, Xinghong Yang, Heng Zhai
Photosystem II (PSII) in plants is susceptible to high temperatures. The cyclic electron flow (CEF) around PSI is thought to protect both PSII and PSI from photodamage. However, the underlying physiological mechanisms of the photosynthetic electron transport process and the role of CEF in grape at high temperatures remain unclear. To investigate this issue, we examined the responses of PSII energy distribution, the P700 redox state and CEF to high temperatures in grape leaves. After exposing 'Cabernet Sauvignon' leaves to various temperatures (25, 30, 35, 40 and 45°C) in the light (600μmol photons m(-2)s(-1)) for 4h, the maximum quantum yield of PSII (Fv/Fm) significantly decreased at high temperatures (40 and 45°C), while the maximum photo-oxidizable P700 (Pm) was not affected...
March 2017: Plant Science: An International Journal of Experimental Plant Biology
keyword
keyword
13408
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"