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Internal photoprotection

W D Abdul Kadir, A Jamil, S Sazliyana Shaharir, N Md Nor, A H Abdul Gafor
Objective The objective of this paper is to determine photoprotection awareness, knowledge, practices, and its relationship with disease activity and damage in patients with systemic lupus erythematosus (SLE). Methods A cross-sectional study was performed. Data were acquired from in-person interviews and medical records. Results A total of 199 (89.6%) females and 23 (10.4%) males were recruited. Median age was 39.00 (interquartile range (IQR) 18) years, disease duration 12.12 (IQR 8) years, Fitzpatrick skin phototype III 119 (53...
January 1, 2018: Lupus
Fen Zhou, Xin Huang, Yun Pan, Di Cao, Chuan Liu, Yiyi Liu, Aijun Chen
The skin is the outermost protective barrier between the internal and external environment in humans. Chronic exposure to ultraviolet (UV) radiation is a major cause of photoaging. Evidence suggests that resveratrol suppresses UVB-induced photoaging. In this study, we aimed to investigate the protective effects of resveratrol against UVB-induced photoaging in HaCaT cells and to determine the underlying mechanisms. Apoptosis of normal or HSP27-overexpressing HaCaT cells in the presence of UVB was analyzed by flow cytometry...
March 28, 2018: Biochemical and Biophysical Research Communications
Carlo Mainetti, Benedetta Terziroli Beretta-Piccoli, Carlo Selmi
Dermatomyositis (DM) is an idiopathic inflammatory myopathy characterized by the presence of skin lesions and inflammation of skeletal muscles; however, this feature may be absent in amyopathic DM. DM is a rare disease, occurring at any age, and has two peaks of incidence: one in childhood between 5 and 15 years of age and one in adulthood between 40 and 60 years, with a female preponderance. DM has been associated with malignancy; therefore, every newly diagnosed patient should undergo screening investigations, but evidence-based guidelines on their extension are lacking...
December 2017: Clinical Reviews in Allergy & Immunology
Giuseppina Ioele, Michele De Luca, Antonio Garofalo, Gaetano Ragno
Nowadays, an exciting challenge in the drug chemistry and technology research is represented by the development of methods aimed to protect molecular integrity and therapeutic activity of drugs from effects of light. The photostability characterization is ruled by ICH (The International Council for Harmonization of Technical Requirements for Pharmaceuticals for Human Use), which releases details throughout basic protocols of stability tests to be performed on new medicinal products for human use. The definition of suitable photoprotective systems is fundamental for pharmaceutical manufacturing and for human healthy as well, since light exposure may affect either drugs or drug formulations giving rise even to allergenic or mutagenic by-products...
December 2017: Drug Delivery
Tinghong Tan, Yanni Sun, Shishuai Luo, Chao Zhang, Huapeng Zhou, Honghui Lin
Boea hygrometrica (B. hygrometrica) can tolerate severe desiccation and resume photosynthetic activity rapidly upon water availability. However, little is known about the mechanisms by which B. hygrometrica adapts to dehydration and resumes competence upon rehydration. Here we determine how B. hygrometrica deals with oxidative stress, excessive excitation/electron pressures as well as photosynthetic apparatus modulation during dehydration/rehydration. By measuring ROS generation and scavenging efficiency, we found that B...
November 1, 2017: Plant & Cell Physiology
Mitsuhiko Miyazaki, Ryuhei Ohara, Claude Dedonder, Christophe Jouvet, Masaaki Fujii
Excited-state hydrogen transfer (ESHT) is responsible for various photochemical processes of aromatics, including photoprotection of nuclear basis. Its mechanism is explained by internal conversion from the aromatic ππ* to πσ* states via conical intersection. This means that the electron is transferred to a diffuse Rydberg-like σ* orbital apart from proton migration. This picture means the electron and the proton do not move together and the dynamics are different in principle. Here, we have applied picosecond time-resolved near-infrared (NIR) and infrared (IR) spectroscopy to the phenol-(NH3 )5 cluster, the benchmark system of ESHT, and monitored the electron transfer and proton motion independently...
January 19, 2018: Chemistry: a European Journal
Jessica Walburn, Robert Sarkany, Sam Norton, Lesley Foster, Myfanwy Morgan, Kirby Sainsbury, Vera Araújo-Soares, Rebecca Anderson, Isabel Garrood, Jakob Heydenreich, Falko F Sniehotta, Rute Vieira, Hans Christian Wulf, John Weinman
INTRODUCTION: Xeroderma pigmentosum (XP) is a rare genetic condition caused by defective nucleotide excision repair and characterised by skin cancer, ocular and neurological involvement. Stringent ultraviolet protection is the only way to prevent skin cancer. Despite the risks, some patients' photoprotection is poor, with a potentially devastating impact on their prognosis. The aim of this research is to identify disease-specific and psychosocial predictors of photoprotection behaviour and ultraviolet radiation (UVR) dose to the face...
August 21, 2017: BMJ Open
Lars Nichelmann, Wolfgang Bilger
Up to 40% of incident light was screened in red Berberis leaves in vivo by anthocyanins, resulting also in up to 40% reduction of light-limited photosynthesis. The biological function of anthocyanins in leaves has been strongly discussed, but the hypothesis of a screening function is favored by most authors. For an evaluation of the function as photoprotective pigments, a quantification of their screening of the mesophyll is important. Here, chlorophyll fluorescence excitation of leaves of a red and a green variety of Berberis thunbergii was used to estimate the extent of screening by anthocyanins at 545 nm and over the whole photosynthetically active wavelength range...
December 2017: Planta
Beatriz Fernández-Marín, Antonio Hernández, Jose I Garcia-Plazaola, Raquel Esteban, Fátima Míguez, Unai Artetxe, Maria T Gómez-Sagasti
Despite being a small geographic extension, Mediterranean Basin is characterized by an exceptional plant biodiversity. Adaptive responses of this biocoenosis are delineated by an unusual temporal dissociation along the year between optimal temperature for growth and water availability. This fact generates the combination of two environmental stress factors: a period of summer drought, variable in length and intensity, and the occurrence of mild to cold winters. Both abiotic factors, trigger the generation of (photo)oxidative stress and plants orchestrate an arsenal of structural, physiological, biochemical, and molecular mechanisms to withstand such environmental injuries...
2017: Frontiers in Plant Science
Lewis A Baker, Sarah L Clark, Scott Habershon, Vasilios G Stavros
The ultrafast photoprotection mechanisms in operation in ethylhexyl triazone (EHT, octyl triazone), an approved ultraviolet-B (UV-B) chemical filter for commercial sunscreens, remain elusive, with a notable absence of ultrafast time-resolved measurements. These large organic molecules are of increasing interest as they are suspected to be less likely to penetrate the skin than some of the smaller approved filters, thereby reducing the possible adverse effects from sunscreen products. We apply femtosecond transient absorption spectroscopy with electronic structure calculations to unravel the complete photodeactivation mechanism that EHT undergoes after UV-B irradiation...
May 18, 2017: Journal of Physical Chemistry Letters
Pierre Çarçabal, Dominique Descamps, Stéphane Petit, Yann Mairesse, Valérie Blanchet, Raluca Cireasa
5-Fluorouracil (5FU) is a radiosensitiser molecule routinely used in combined chemo- and radio-therapies to enhance and localize cancer treatments. We have employed ultra-short XUV pulses produced by high harmonic generation (HHG) as a pump pulse to study the dynamics underlying the photo-stability and the radiation damage of this molecule. This work shows that it is possible to resolve individual dynamics even when using unselected HH. By comparing the results with those obtained in the multiphoton absorption at 400 nm, we were able to identify the frequencies of the HH comb relevant to the recorded dynamics: HH5 and HH3...
December 16, 2016: Faraday Discussions
Yi Xiao, Danny Tholen, Xin-Guang Zhu
Leaf photosynthesis is determined by biochemical properties and anatomical features. Here we developed a three-dimensional leaf model that can be used to evaluate the internal light environment of a leaf and its implications for whole-leaf electron transport rates (J). This model includes (i) the basic components of a leaf, such as the epidermis, palisade and spongy tissues, as well as the physical dimensions and arrangements of cell walls, vacuoles and chloroplasts; and (ii) an efficient forward ray-tracing algorithm, predicting the internal light environment for light of wavelengths between 400 and 2500nm...
November 2016: Journal of Experimental Botany
Yazhe Wang, Cheng Wang, Yang Ding, Jing Li, Min Li, Xiao Liang, Jianping Zhou, Wei Wang
Photodynamic therapy has emerged as a promising strategy for cancer treatment. To ensure the efficient delivery of a photosensitizer to tumor for anticancer effect, a safe and tumor-specific delivery system is highly desirable. Herein, we introduce a novel biomimetic nanoparticle named rHDL/ICG (rHDL/I), by loading amphiphilic near-infrared (NIR) fluorescent dye indocyanine green (ICG) into reconstituted high density lipoproteins (rHDL). In this system, rHDL can mediate photoprotection effect and receptor-guided tumor-targeting transportation of cargos into cells...
December 1, 2016: Colloids and Surfaces. B, Biointerfaces
Nuria Blázquez-Sánchez, Magdalena De Troya-Martín, Francisco Rivas-Ruiz, Sara Bueno-Fernández, Maria Teresa Fernández-Morano, Salvador Arias-Santiago
Sun exposure in childhood is the main risk determinant for skin cancer in adulthood. Several questionnaires have been used to examine behaviour patterns in terms of sun exposure in childhood, but none have been subjected to a rigorous analysis of their measurement properties. To evaluate the psychometric properties of a questionnaire adapted to investigate children's sun exposure behaviour, a two-stage validation study was carried out. First, in a transverse study, the questionnaire was administered to a sample of 333 children recruited from schools, and the validity and internal consistency were analysed...
January 2018: European Journal of Cancer Prevention
Federico Gonzalez-Fernandez, Brandi Betts-Obregon, Andrew T Tsin, Richard J DeSa
PURPOSE: Assaying photodecomposition is challenging because light must be used to initiate the photodamage and light must be used to monitor the photodecomposition. The experimental requirements are as follows: 1) During exposure of the actinic beam, continuously monitor the spectral characteristics of the sample, 2) uniformly expose the reactants to the actinic source, 3) obtain informative spectra in the presence of light scatter, and 4) achieve sufficient sensitivity for dilute reactants...
2016: Molecular Vision
Marko Kojić, Milena Petković, Mihajlo Etinski
Avobenzone (4-tert-butyl-4'-methoxydibenzoylmethane, AB) is one of the most widely used filters in sunscreens for skin photoprotection in the UVA band. The photochemistry of AB includes keto-enol tautomerization, cis-trans isomerization, rotation about the single bond and α bond cleavages of carbonyl groups. In this contribution we study chelated and non-chelated enol, rotamers Z and E, and keto tautomers of AB in the ground and excited states in gas phase and acetonitrile by means of a coupled cluster method...
August 10, 2016: Physical Chemistry Chemical Physics: PCCP
Vera Slaveykova, Bettina Sonntag, Juan Carlos Gutiérrez
We report a summary of the symposium "Stress and Protists: No life without stress", which was held in September 2015 on the VII European Congress of Protistology in partnership with the International Society of Protistologists (Seville, Spain). We present an overview on general comments and concepts on cellular stress which can be also applied to any protist. Generally, various environmental stressors may induce similar cell responses in very different protists. Two main topics are reported in this manuscript: (i) metallic nanoparticles as environmental pollutants and stressors for aquatic protists, and (ii) ultraviolet radiation - induced stress and photoprotective strategies in ciliates...
August 2016: European Journal of Protistology
I Aloisi, G Cai, D Serafini-Fracassini, S Del Duca
Transglutaminases (TGases) are ubiquitous enzymes catalyzing many biological reactions. The best-known TGase activity, namely the transamidation of specific proteins by polyamines (PAs), has been studied in plants to verify if TGase is a mediator of PAs mechanism of action to re-interpret some of PAs effects. Usually, the TGase activity is present at basal level in plant cells, but it can be induced by internal or external events or stresses, like rehydration, wounding, light, developmental differentiation and programmed cell death (PCD)...
October 2016: Amino Acids
Michele De Luca, Giuseppina Ioele, Claudia Spatari, Gaetano Ragno
1,4-dihydropyridine antihypertensives (DHPs) are almost all dispensed in solid pharmaceutical formulations for their easy lability when exposed to light. This paper reports a study on the photoprotective effect of containers in different glassy or polymeric matrices with regard to four known DHPs when in solutions. The samples were subjected to forced degradation by means of a Xenon lamp, in accordance with the international rules on drug stability evaluation. The simultaneous determination of the drugs and their photoproducts was carried out by applying the multivariate curve resolution (MCR) methodology to the spectral data recorded along the irradiation test...
May 30, 2016: International Journal of Pharmaceutics
Lewis A Baker, Michael D Horbury, Simon E Greenough, Florent Allais, Patrick S Walsh, Scott Habershon, Vasilios G Stavros
We explore the ultrafast photoprotective properties of a series of sinapic acid derivatives in a range of solvents, utilizing femtosecond transient electronic absorption spectroscopy. We find that a primary relaxation mechanism displayed by the plant sunscreen sinapoyl malate and other related molecular species may be understood as a multistep process involving internal conversion of the initially photoexcited 1(1)ππ* state along a trans-cis photoisomerization coordinate, leading to the repopulation of the original trans ground-state isomer or the formation of a stable cis isomer...
January 7, 2016: Journal of Physical Chemistry Letters
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