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Trescher TF, da Silva RJ, Souto PCS, Silva JR, de Souza NC. Growth models of fractal interfaces in the description of microorganism colony growth: effect of photodynamic inactivation. Photochem Photobiol Sci 2023; 22:311-318. [PMID: 36216976 DOI: 10.1007/s43630-022-00315-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Accepted: 09/26/2022] [Indexed: 11/24/2022]
Abstract
Candida albicans is responsible for most of the nosocomial infections that affect immunocompromised individuals. We investigated the application of eosin in photodynamic inactivation as a strategy in the inhibition of the growth of C. albicans and the morphological variation and growth dynamics in light of fractal theory. The damage caused to fungal structures alters the roughness of the colony, and these changes were described by parameters that were defined by mathematical models. Proliferation of the fungi should be inhibited in the center of the colonies and the analysis of the edges gives an indication about the dynamics of growth and cell reproduction.
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Affiliation(s)
- Tarquin F Trescher
- Grupo de Materiais Nanoestruturados, Universidade Federal de Mato Grosso, Barra do Garças, Mato Grosso, Brazil
| | - Romário J da Silva
- Grupo de Materiais Nanoestruturados, Universidade Federal de Mato Grosso, Barra do Garças, Mato Grosso, Brazil
| | - Paula C S Souto
- Grupo de Materiais Nanoestruturados, Universidade Federal de Mato Grosso, Barra do Garças, Mato Grosso, Brazil
| | - Josmary R Silva
- Grupo de Materiais Nanoestruturados, Universidade Federal de Mato Grosso, Barra do Garças, Mato Grosso, Brazil
| | - Nara C de Souza
- Grupo de Materiais Nanoestruturados, Universidade Federal de Mato Grosso, Barra do Garças, Mato Grosso, Brazil. .,Laboratório de Nanosistemas E Tecnologias, Universidade Federal de Goiás, Aparecida de Goiânia, Goiás, Brazil.
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2
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Liu L, Zhang D, Johnson M, Devaraj NK. Light-activated tetrazines enable precision live-cell bioorthogonal chemistry. Nat Chem 2022; 14:1078-1085. [PMID: 35788560 PMCID: PMC10198265 DOI: 10.1038/s41557-022-00963-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Accepted: 05/03/2022] [Indexed: 02/07/2023]
Abstract
Bioorthogonal cycloaddition reactions between tetrazines and strained dienophiles are widely used for protein, lipid and glycan labelling because of their extremely rapid kinetics. However, controlling this chemistry in the presence of living mammalian cells with a high degree of spatial and temporal precision remains a challenge. Here we demonstrate a versatile approach to light-activated formation of tetrazines from photocaged dihydrotetrazines. Photouncaging, followed by spontaneous transformation to reactive tetrazine, enables live-cell spatiotemporal control of rapid bioorthogonal cycloaddition with dienophiles such as trans-cyclooctenes. Photocaged dihydrotetrazines are stable in conditions that normally degrade tetrazines, enabling efficient early-stage incorporation of bioorthogonal handles into biomolecules such as peptides. Photocaged dihydrotetrazines allow the use of non-toxic light to trigger tetrazine ligations on living mammalian cells. By tagging reactive phospholipids with fluorophores, we demonstrate modification of HeLa cell membranes with single-cell spatial resolution. Finally, we show that photo-triggered therapy is possible by coupling tetrazine photoactivation with strategies that release prodrugs in response to tetrazine ligation.
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Affiliation(s)
- Luping Liu
- Department of Chemistry and Biochemistry, University of California, San Diego, CA, USA
| | - Dongyang Zhang
- Department of Chemistry and Biochemistry, University of California, San Diego, CA, USA
| | - Mai Johnson
- Department of Chemistry and Biochemistry, University of California, San Diego, CA, USA
| | - Neal K Devaraj
- Department of Chemistry and Biochemistry, University of California, San Diego, CA, USA.
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3
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Xu J, Liang Q, Li Z, Osipov VY, Lin Y, Ge B, Xu Q, Zhu J, Bi H. Rational Synthesis of Solid-State Ultraviolet B Emitting Carbon Dots via Acetic Acid-Promoted Fractions of sp 3 Bonding Strategy. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2022; 34:e2200011. [PMID: 35246877 DOI: 10.1002/adma.202200011] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Revised: 02/28/2022] [Indexed: 06/14/2023]
Abstract
Carbon dots (CDs) have received tremendous attention for their excellent photoluminescence (PL) properties. However, it remains a great challenge to obtain CDs with ultraviolet (UV, 200-400 nm) emission in solid state, which requires strict control of the CDs structure and overcoming the aggregation-caused quenching (ACQ). Herein, a new sp3 compartmentalization strategy is developed to meet these requirements, by employing acetic acid to promote fractions of sp3 bonding during the synthesis of CDs. It markedly decreases the size of sp2 conjugating units in the CDs, and shifts PL emission to the ultraviolet B (UVB) region (λmax = 308 nm). Moreover, sp2 domains are well spatially compartmentalized by sp3 domains and the ACQ effect is minimized, enabling the high quantum yield in solid state (20.2%, λex = 265 nm) with a narrow bandwidth of 24 nm and environmental robustness. The solid-state UVB emissive CDs are highly desired for application in photonic devices. Hence, a demo of UVB light-emitting diodes is fabricated for plant lighting, leading to a 29% increase of ascorbic acid content in the basil. Overall, a rational and efficient way to construct solid UVB-CDs phosphors for wide applications is provided.
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Affiliation(s)
- Jiahui Xu
- School of Chemistry and Chemical Engineering, Anhui University, 111 Jiulong Road, Hefei, 230601, China
| | - Qingjing Liang
- School of Chemistry and Chemical Engineering, Anhui University, 111 Jiulong Road, Hefei, 230601, China
| | - Zijian Li
- School of Materials Science and Engineering, Anhui University, 111 Jiulong Road, Hefei, 230601, China
| | | | - Yangjian Lin
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Physical Science and Information Technology, Anhui University, 111 Jiulong Road, Hefei, 230601, China
| | - Binghui Ge
- Information Materials and Intelligent Sensing Laboratory of Anhui Province, Institutes of Physical Science and Information Technology, Anhui University, 111 Jiulong Road, Hefei, 230601, China
| | - Qian Xu
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, 42 South Hezuohua Road, Hefei, Anhui, 230029, China
| | - Junfa Zhu
- National Synchrotron Radiation Laboratory, University of Science and Technology of China, 42 South Hezuohua Road, Hefei, Anhui, 230029, China
| | - Hong Bi
- School of Chemistry and Chemical Engineering, Anhui University, 111 Jiulong Road, Hefei, 230601, China
- School of Materials Science and Engineering, Anhui University, 111 Jiulong Road, Hefei, 230601, China
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4
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Facemask Global Challenges: The Case of Effective Synthesis, Utilization, and Environmental Sustainability. SUSTAINABILITY 2022. [DOI: 10.3390/su14020737] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Coronavirus disease (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has caused a rapidly spreading pandemic and is severely threatening public health globally. The human-to-human transmission route of SARS-CoV-2 is now well established. The reported clinical observations and symptoms of this infection in humans appear in the range between being asymptomatic and severe pneumonia. The virus can be transmitted through aerosols and droplets that are released into the air by a carrier, especially when the person coughs, sneezes, or talks forcefully in a closed environment. As the disease progresses, the use and handling of contaminated personal protective equipment and facemasks have become major issues with significant environmental risks. Therefore, providing an effective method for treating used/contaminated facemasks is crucial. In this paper, we review the environmental challenges and risks associated with the surge in facemask production. We also discuss facemasks and their materials as sources of microplastics and how disposal procedures can potentially lead to the contamination of water resources. We herein review the potential of developing nanomaterial-based antiviral and self-cleaning facemasks. This review discusses these challenges and concludes that the use of sustainable and alternative facemask materials is a promising and viable solution. In this context, it has become essential to address the emerging challenges by developing a new class of facemasks that are effective against the virus, while being biodegradable and sustainable. This paper represents the potentials of natural and/or biodegradable polymers for manufacturing facemasks, such as wood-based polymers, chitosan, and other biodegradable synthetic polymers for achieving sustainability goals during and after pandemics.
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5
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Mubeen M, Khalid MA, Mukhtar M, Shahrum S, Zahra S, Shabbir S, Iqbal A. Elucidating the Photoluminescence Quenching in Ensulizole: an Artificial Water Soluble Sunscreen. J Fluoresc 2021; 31:1055-1063. [PMID: 33956267 DOI: 10.1007/s10895-021-02736-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 05/03/2021] [Indexed: 10/21/2022]
Abstract
Employing natural or artificial sunscreens is essential to protect the skin from ultraviolet radiations that cause premature aging and develop melanoma and other forms of skin cancer. The 2-Phenylbenzimidazole-5-sulfonic acid, commonly known as ensulizole is a water-soluble artificial sunscreen that absorb UV-B (280 nm - 315 nm) radiations and protects the skin against the harmful effects of these radiations. We have measured steady-state photoluminescence (SSPL) spectra and photoluminescence (PL) kinetics of this compound in various conditions. Steady-state absorption indicates a strong absorption feature at 303 nm and a weak one at 316 nm that have been identified as π → π* and n → π* transitions, respectively. The spectra of PL induced by these absorptions indicate that the PL of ensulizole is less Stokes-shifted in polar solvents and more Stokes-shifted in non-polar solvents. The average PL lifetime of ensulizole is longer in non-polar solvents than in polar solvents and it exhibits the shortest PL lifetime in aqueous medium that maximize its transition efficiency in water. This suggests in non-polar solvents intersystem crossing is the dominant mode of relaxation of the excited ππ* state. Furthermore, an increase of pH of ensulizole solution decreases the PL intensity and the lifetime. Stern-Volmer equation is employed to evaluate bimolecular quenching rate constant kq. The evaluation result suggests the diffusional dynamic mode of PL quenching is operative.
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Affiliation(s)
- Muhammad Mubeen
- Department of Chemistry, Quaid-I-Azam University, Islamabad, 45320, Pakistan
| | | | - Maria Mukhtar
- Department of Chemistry, Quaid-I-Azam University, Islamabad, 45320, Pakistan
| | - Saba Shahrum
- Department of Chemistry, Quaid-I-Azam University, Islamabad, 45320, Pakistan
| | - Shanila Zahra
- Department of Chemistry, Quaid-I-Azam University, Islamabad, 45320, Pakistan
| | - Saima Shabbir
- Department of Materials Science and Engineering, Institute of Space Technology, 44000, Islamabad, Pakistan
| | - Azhar Iqbal
- Department of Chemistry, Quaid-I-Azam University, Islamabad, 45320, Pakistan.
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6
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Kwon J, Kim SG, Kim HJ, Giri SS, Kim SW, Lee SB, Park SC. Bacteriophage as an alternative to prevent reptile-associated Salmonella transmission. Zoonoses Public Health 2021; 68:131-143. [PMID: 33455089 DOI: 10.1111/zph.12804] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 12/25/2020] [Accepted: 12/26/2020] [Indexed: 01/21/2023]
Abstract
Salmonellosis is a major global public health issue; its most common infection, gastroenteritis, accounts for approximately 90 million illnesses and 150,000 mortalities per year. Eradicating salmonellosis requires surveillance, prevention and treatment, entailing large expenditures. However, it is difficult to control Salmonella transmission because it occurs via multiple routes; exotic reptiles are a reservoir of Salmonella and comprise one such route. As the popularity of exotic pets and animal exhibition has increased, human encounters with reptiles have also increased. As a result, reptile-associated salmonellosis (RAS) has been recognized as an emerging disease. The development of antimicrobial resistance in RAS-causing Salmonella sp. requires alternatives to antibiotics. In this study, bacteriophages have been established as an alternative to antibiotics because only target bacteria are lysed; thus, they are promising biocontrol agents. Here, bacteriophage pSal-SNUABM-02, which infects and lyses reptile Salmonella isolates, was isolated and characterized. The morphology, host range, growth traits and stability of the phage were investigated. The phage was assigned to Myoviridae and was stable in the following conditions: pH 5-9, 4-37°C, and ultravioletA/ultravioletB (UVA/UVB) exposure. Salmonella clearance efficacy was tested using planktonic cell lysis activity and biofilm degradation on polystyrene 96-well plates and reptile skin fragments. The phage exhibited vigorous lysis activity against planktonic cells. In in vitro biofilm degradation tests on reptile skin and polystyrene plates, both low- and high-concentration phage treatments lowered bacterial cell viability by approximately 2.5-3 log colony-forming units and also decreased biomass. Thus, bacteriophages are a promising alternative to antibiotics for the prevention and eradication of RAS.
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Affiliation(s)
- Jun Kwon
- Laboratory of Aquatic Biomedicine, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | - Sang Geun Kim
- Laboratory of Aquatic Biomedicine, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | - Hyoun Joong Kim
- Laboratory of Aquatic Biomedicine, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | - Sib Sankar Giri
- Laboratory of Aquatic Biomedicine, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | - Sang Wha Kim
- Laboratory of Aquatic Biomedicine, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | - Sung Bin Lee
- Laboratory of Aquatic Biomedicine, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
| | - Se Chang Park
- Laboratory of Aquatic Biomedicine, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul, Korea
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7
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Abiola TT, Whittock AL, Stavros VG. Unravelling the Photoprotective Mechanisms of Nature-Inspired Ultraviolet Filters Using Ultrafast Spectroscopy. Molecules 2020; 25:E3945. [PMID: 32872380 PMCID: PMC7504748 DOI: 10.3390/molecules25173945] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2020] [Revised: 08/26/2020] [Accepted: 08/27/2020] [Indexed: 02/07/2023] Open
Abstract
There are several drawbacks with the current commercially available ultraviolet (UV) filters used in sunscreen formulations, namely deleterious human and ecotoxic effects. As a result of the drawbacks, a current research interest is in identifying and designing new UV filters. One approach that has been explored in recent years is to use nature as inspiration, which is the focus of this review. Both plants and microorganisms have adapted to synthesize their own photoprotective molecules to guard their DNA from potentially harmful UV radiation. The relaxation mechanism of a molecule after it has been photoexcited can be unravelled by several techniques, the ones of most interest for this review being ultrafast spectroscopy and computational methods. Within the literature, both techniques have been implemented on plant-, and microbial-inspired UV filters to better understand their photoprotective roles in nature. This review aims to explore these findings for both families of nature-inspired UV filters in the hope of guiding the future design of sunscreens.
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Affiliation(s)
- Temitope T. Abiola
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK; (T.T.A.); (A.L.W.)
| | - Abigail L. Whittock
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK; (T.T.A.); (A.L.W.)
- AS CDT, Senate House, University of Warwick, Coventry CV4 7AL, UK
| | - Vasilios G. Stavros
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK; (T.T.A.); (A.L.W.)
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8
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Yang X, Liu TC, Liu S, Zhu W, Li H, Liang P, Ye S, Cui S. Promoted Viability and Differentiated Phenotype of Cultured Chondrocytes With Low Level Laser Irradiation Potentiate Efficacious Cells for Therapeutics. Front Bioeng Biotechnol 2020; 8:468. [PMID: 32548098 PMCID: PMC7272569 DOI: 10.3389/fbioe.2020.00468] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 04/22/2020] [Indexed: 12/03/2022] Open
Abstract
Effective clinical treatments of cartilage lesions in affected joints require large numbers of viable chondrogenic cells generated through in vivo stimulation or ex vivo expansion of chondrocytes isolated from small biopsy specimens. Conventional passaging of chondrocytes in culture provides sufficient cells for treatments but these cells usually lose their differentiated phenotype. This leads to the formation of fibrocartilaginous tissue due to a malfunctioning repair process. Biostimulation of passaging chondrocytes with low level laser irradiation (LLLI) may theoretically produce more functional chondrocytes for cell-based repair of cartilage defects. Molecular and cellular analyses, cytochemistry, cell cultivation, and microscopy showed that LLLI treatments were found to (1) increase chondrocyte viability, (2) promote secretion of matrix proteins, (3) upregulate expression of chondrogenic genes, and (4) downregulate gene expression of cell destructive proteases and genes coding for mediators involved in the extrinsic apoptosis signaling pathway. Furthermore, LLLI attenuated induction of genes associated with cell death and matrix breakdown induced by IL-1β, some of which was seen at the protein level, with verification of effects on gene expression in the C28/I2 human chondrocyte line. LLLI treatments during culture generated larger numbers of viable chondrocytes compared to untreated cultures. Moreover, LLLI-treated chondrocytes in culture also rectified and simultaneously maintained their differentiated phenotype. Cultured chondrocytes treated with LLLI are a promising cell source for repairing cartilage lesions in vivo and restoration of articular function using tissue engineering strategies.
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Affiliation(s)
- Xiaohong Yang
- Guangzhou Institute of Traumatic Surgery, Guangzhou Red Cross Hospital, School of Medicine, Jinan University, Guangzhou, China
| | - Timon Chengyi Liu
- Laboratory of Laser Sports Medicine, College of Physical Education and Sports Medicine, South China Normal University, Guangzhou, China
| | - Shaojie Liu
- Surgical Department, Guangzhou Red Cross Hospital, School of Medicine, Jinan University, Guangzhou, China
| | - Weicong Zhu
- Guangzhou Institute of Traumatic Surgery, Guangzhou Red Cross Hospital, School of Medicine, Jinan University, Guangzhou, China
| | - Honglin Li
- Guangzhou Institute of Traumatic Surgery, Guangzhou Red Cross Hospital, School of Medicine, Jinan University, Guangzhou, China
| | - Peihong Liang
- Guangzhou Institute of Traumatic Surgery, Guangzhou Red Cross Hospital, School of Medicine, Jinan University, Guangzhou, China
| | - Suihui Ye
- Surgical Department, Guangzhou Red Cross Hospital, School of Medicine, Jinan University, Guangzhou, China
| | - Shuliang Cui
- Guangzhou Institute of Traumatic Surgery, Guangzhou Red Cross Hospital, School of Medicine, Jinan University, Guangzhou, China.,School of BioSciences, The University of Melbourne, Melbourne, VIC, Australia
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9
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DeMarini DM. The mutagenesis moonshot: The propitious beginnings of the environmental mutagenesis and genomics society. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2020; 61:8-24. [PMID: 31294870 PMCID: PMC6949362 DOI: 10.1002/em.22313] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 06/20/2019] [Indexed: 05/05/2023]
Abstract
A mutagenesis moonshot addressing the influence of the environment on our genetic wellbeing was launched just 2 months before astronauts landed on the moon. Its impetus included the discovery that X-rays (Muller HJ. [1927]: Science 64:84-87) and chemicals (Auerbach and Robson. [1946]: Nature 157:302) were germ-cell mutagens, the introduction of a growing number of untested chemicals into the environment after World War II, and an increasing awareness of the role of environmental pollution on human health. Due to mounting concern from influential scientists that germ-cell mutagens might be ubiquitous in the environment, Alexander Hollaender and colleagues founded in 1969 the Environmental Mutagen Society (EMS), now the Environmental Mutagenesis and Genomics Society (EMGS); Frits Sobels founded the European EMS in 1970. As Fred de Serres noted, such societies were necessary because protecting populations from environmental mutagens could not be addressed by existing scientific societies, and new multidisciplinary alliances were required to spearhead this movement. The nascent EMS gathered policy makers and scientists from government, industry, and academia who became advocates for laws requiring genetic toxicity testing of pesticides and drugs and helped implement those laws. They created an electronic database of the mutagenesis literature; established a peer-reviewed journal; promoted basic and applied research in DNA repair and mutagenesis; and established training programs that expanded the science worldwide. Despite these successes, one objective remains unfulfilled: identification of human germ-cell mutagens. After 50 years, the voyage continues, and a vibrant EMGS is needed to bring the mission to its intended target of protecting populations from genetic hazards. Environ. Mol. Mutagen. 61:8-24, 2020. © 2019 Wiley Periodicals, Inc.
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Affiliation(s)
- David M. DeMarini
- National Health and Environmental Effects Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina
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10
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Non-use of sunscreen among adults and the elderly in southern Brazil. An Bras Dermatol 2019; 94:567-573. [PMID: 31777358 PMCID: PMC6857572 DOI: 10.1016/j.abd.2018.10.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Accepted: 10/25/2018] [Indexed: 11/22/2022] Open
Abstract
Background One of the main prevention methods against skin cancer is the use of sunscreen; however, incidence of this disease has not declined despite prevention campaigns. Objective Investigate the prevalence of non-use of sunscreen and its associated factors. Method A population-based cross-sectional study with individuals aged 18 years or over living in the urban area. Conducted between April and July of 2016. Participants were interviewed about socioeconomic, demographic, and behavioral questions. Non-use of sunscreen was considered as the outcome. For multivariate analysis, Poisson regression with robust adjustment for variance was used. Results Among the 1300 participants, prevalence of non-use of sunscreen was 38.2% (95% CI: 34.6–41.8). The variables independently associated with the outcome were male sex, older age, brown or black skin color, lower income, fewer years of education, no physical activity in leisure time, no medical consultations in the last year, and self-perception of health as regular or poor. Study limitations The prevalence may be underestimated by reports of more use of sunscreen than actually used, which could increase the figure in the outcome. Conclusion It was estimated that about four out of ten adults and elderly do not use sunscreen in this sample. Prevention strategies are needed to advance health policy and ensure that sun protection options are easily accessible.
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11
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Epitaxy of III-Nitrides on β-Ga 2O 3 and Its Vertical Structure LEDs. MICROMACHINES 2019; 10:mi10050322. [PMID: 31086010 PMCID: PMC6562507 DOI: 10.3390/mi10050322] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2019] [Revised: 04/28/2019] [Accepted: 05/08/2019] [Indexed: 11/20/2022]
Abstract
β-Ga2O3, characterized with high n-type conductivity, little lattice mismatch with III-Nitrides, high transparency (>80%) in blue, and UVA (400–320 nm) as well as UVB (320–280 nm) regions, has great potential as the substrate for vertical structure blue and especially ultra violet LEDs (light emitting diodes). Large efforts have been made to improve the quality of III-Nitrides epilayers on β-Ga2O3. Furthermore, the fabrication of vertical blue LEDs has been preliminarily realized with the best result that output power reaches to 4.82 W (under a current of 10 A) and internal quantum efficiency (IQE) exceeds 78% by different groups, respectively, while there is nearly no demonstration of UV-LEDs on β-Ga2O3. In this review, with the perspective from materials to devices, we first describe the basic properties, growth method, as well as doping of β-Ga2O3, then introduce in detail the progress in growth of GaN on (1 0 0) and (−2 0 1) β-Ga2O3, followed by the epitaxy of AlGaN on gallium oxide. Finally, the advances in fabrication and performance of vertical structure LED (VLED) are presented.
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12
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MacKenzie AF, Maltby EA, Harper N, Bueley C, Olender D, Wyeth RC. Periodic ultraviolet-C illumination for marine sensor antifouling. BIOFOULING 2019; 35:483-493. [PMID: 31177838 DOI: 10.1080/08927014.2019.1616698] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/03/2018] [Revised: 04/11/2019] [Accepted: 05/04/2019] [Indexed: 05/22/2023]
Abstract
Ultraviolet light has intriguing potential as a marine antifoulant, targeting almost any species and applicable to almost any surface, while not accumulating in the environment. This study field-tested the effects of periodic ultraviolet-C illumination on marine macrofouling. Across four experiments, several UV illumination duty cycles were tested against controls with no illumination. Duty cycles between 1:2 (time with UV:total time per cycle) and 1:20 were all similarly effective, inhibiting almost all macrofouling at three different temperate Northeast Pacific and Northwest Atlantic sites. Susceptible taxa included barnacles, bryozoans, tunicates (colonial and solitary), and, to a slightly lesser extent, mussels. Duty cycles of 1:30 and 1:60 reduced but did not eliminate biofouling. Measurements of ultraviolet illumination on oceanographic sensors showed similar results. The results suggest further investigation of ultraviolet light as an antifoulant for marine sensors, including susceptibility of other taxa, optimizing illumination patterns, and exploring the potential for evolved resistance.
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Affiliation(s)
- Amelia F MacKenzie
- Department of Biology, St. Francis Xavier University , Antigonish , Nova Scotia , Canada
- Centre for Biofouling Research, St. Francis Xavier University , Antigonish , Nova Scotia , Canada
| | - Ella A Maltby
- Department of Biology, St. Francis Xavier University , Antigonish , Nova Scotia , Canada
- Centre for Biofouling Research, St. Francis Xavier University , Antigonish , Nova Scotia , Canada
- Bamfield Marine Sciences Centre , Bamfield , British Columbia , Canada
| | - Nick Harper
- AML Oceanographic , Sidney , British Columbia , Canada
| | - Chris Bueley
- AML Oceanographic , Sidney , British Columbia , Canada
| | | | - Russell C Wyeth
- Department of Biology, St. Francis Xavier University , Antigonish , Nova Scotia , Canada
- Centre for Biofouling Research, St. Francis Xavier University , Antigonish , Nova Scotia , Canada
- Bamfield Marine Sciences Centre , Bamfield , British Columbia , Canada
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13
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Wang H, Zhou Q, Liang S, Wen R. Fabrication and Characterization of AlGaN-Based UV LEDs with a ITO/Ga₂O₃/Ag/Ga₂O₃ Transparent Conductive Electrode. NANOMATERIALS 2019; 9:nano9010066. [PMID: 30621281 PMCID: PMC6358823 DOI: 10.3390/nano9010066] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 12/27/2018] [Accepted: 12/31/2018] [Indexed: 11/16/2022]
Abstract
We fabricated a complex transparent conductive electrode (TCE) based on Ga₂O₃ for AlGaN-based ultraviolet light-emitting diodes. The complex TCE consists of a 10 nm ITO, a 15 nm Ga₂O₃, a 7 nm Ag, and a 15 nm Ga₂O₃, forming a ITO/Ga₂O₃/Ag/Ga₂O₃ multilayer. The metal layer embedded into Ga₂O₃ and the thin ITO contact layer improves current spreading and electrode contact properties. It is found that the ITO/Ga₂O₃/Ag/Ga₂O₃ multilayer can reach a 92.8% transmittance at 365 nm and a specific contact resistance of 10-3 Ω·cm² with suitable annealing conditions.
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Affiliation(s)
- Hong Wang
- Engineering Research Center for Optoelectronics of Guangdong Province, School of Electronics and Information Engineering, South China University of Technology, Guangzhou 510640, China.
- School of Physics and Optoelectronics, South China university of Technology, Guangzhou 510640, China.
- Zhongshan Institute of Modern Industrial Technology, South China University of Technology, Zhongshan 528437, China.
| | - Quanbin Zhou
- Engineering Research Center for Optoelectronics of Guangdong Province, School of Electronics and Information Engineering, South China University of Technology, Guangzhou 510640, China.
| | - Siwei Liang
- Engineering Research Center for Optoelectronics of Guangdong Province, School of Electronics and Information Engineering, South China University of Technology, Guangzhou 510640, China.
- School of Physics and Optoelectronics, South China university of Technology, Guangzhou 510640, China.
| | - Rulian Wen
- Engineering Research Center for Optoelectronics of Guangdong Province, School of Electronics and Information Engineering, South China University of Technology, Guangzhou 510640, China.
- School of Physics and Optoelectronics, South China university of Technology, Guangzhou 510640, China.
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14
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Negelspach DC, Kaladchibachi S, Fernandez F. The circadian activity rhythm is reset by nanowatt pulses of ultraviolet light. Proc Biol Sci 2018; 285:20181288. [PMID: 30068685 PMCID: PMC6111179 DOI: 10.1098/rspb.2018.1288] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Accepted: 07/09/2018] [Indexed: 12/21/2022] Open
Abstract
The circadian pacemaker synchronizes to the Earth's rotation by tracking step-by-step changes in illumination that occur as the sun passes the horizon. While twilight progressions of irradiance and colour are considered important stimuli in this process, comparably less thought has been given to the possibility that ultraviolet A (UVA) radiation might actually play a more formative role given its evolutionary significance in shaping 24 h timekeeping. Here, we show that Drosophila activity rhythms can be phase-shifted by UVA light at an energy range seated well below that of the visible spectrum. Because the energy threshold for this resetting matches the incident amount of UVA on the human retina at twilight, our results suggest that UVA light has the potential to function as a similar time cue in people.
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Affiliation(s)
| | | | - Fabian Fernandez
- Department of Psychology, University of Arizona, Tucson, AZ, USA
- Department of Neurology, University of Arizona, Tucson, AZ, USA
- BIO5 Institute, University of Arizona, Tucson, AZ, USA
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15
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Aluminum plasmonic nanoshielding in ultraviolet inactivation of bacteria. Sci Rep 2017; 7:9026. [PMID: 28831133 PMCID: PMC5567371 DOI: 10.1038/s41598-017-08593-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Accepted: 07/04/2017] [Indexed: 01/27/2023] Open
Abstract
Ultraviolet (UV) irradiation is an effective bacterial inactivation technique with broad applications in environmental disinfection. However, biomedical applications are limited due to the low selectivity, undesired inactivation of beneficial bacteria and damage of healthy tissue. New approaches are needed for the protection of biological cells from UV radiation for the development of controlled treatment and improved biosensors. Aluminum plasmonics offers attractive opportunities for the control of light-matter interactions in the UV range, which have not yet been explored in microbiology. Here, we investigate the effects of aluminum nanoparticles (Al NPs) prepared by sonication of aluminum foil on the UVC inactivation of E. coli bacteria and demonstrate a new radiation protection mechanism via plasmonic nanoshielding. We observe direct interaction of the bacterial cells with Al NPs and elucidate the nanoshielding mechanism via UV plasmonic resonance and nanotailing effects. Concentration and wavelength dependence studies reveal the role and range of control parameters for regulating the radiation dosage to achieve effective UVC protection. Our results provide a step towards developing improved radiation-based bacterial treatments.
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16
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Abstract
Does the level of sunlight affect the tipping percentage in taxicab rides in New York City? We examined this question using data on 13.82 million cab rides from January to October in 2009 in New York City combined with data on hourly levels of solar radiation. We found a small but statistically significant positive relationship between sunlight and tipping, with an estimated tipping increase of 0.5 to 0.7 percentage points when transitioning from a dark sky to full sunshine. The findings are robust to two-way clustering of standard errors based on hour-of-the-day and day-of-the-year and controlling for day-of-the-year, month-of-the-year, cab driver fixed effects, weather conditions, and ride characteristics. The NYC cab ride context is suitable for testing the association between sunlight and tipping due to the largely random assignment of riders to drivers, direct exposure to sunlight, and low confounding from variation in service experiences.
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Affiliation(s)
- Srikant Devaraj
- Center for Business and Economic Research, Miller College of Business, Ball State University, Muncie, Indiana, United States of America
| | - Pankaj C. Patel
- Villanova School of Business, Villanova University, Villanova, Pennsylvania, United States of America
- * E-mail:
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17
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Bodvard K, Peeters K, Roger F, Romanov N, Igbaria A, Welkenhuysen N, Palais G, Reiter W, Toledano MB, Käll M, Molin M. Light-sensing via hydrogen peroxide and a peroxiredoxin. Nat Commun 2017; 8:14791. [PMID: 28337980 PMCID: PMC5376668 DOI: 10.1038/ncomms14791] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 01/27/2017] [Indexed: 02/08/2023] Open
Abstract
Yeast lacks dedicated photoreceptors; however, blue light still causes pronounced oscillations of the transcription factor Msn2 into and out of the nucleus. Here we show that this poorly understood phenomenon is initiated by a peroxisomal oxidase, which converts light into a hydrogen peroxide (H2O2) signal that is sensed by the peroxiredoxin Tsa1 and transduced to thioredoxin, to counteract PKA-dependent Msn2 phosphorylation. Upon H2O2, the nuclear retention of PKA catalytic subunits, which contributes to delayed Msn2 nuclear concentration, is antagonized in a Tsa1-dependent manner. Conversely, peroxiredoxin hyperoxidation interrupts the H2O2 signal and drives Msn2 oscillations by superimposing on PKA feedback regulation. Our data identify a mechanism by which light could be sensed in all cells lacking dedicated photoreceptors. In particular, the use of H2O2 as a second messenger in signalling is common to Msn2 oscillations and to light-induced entrainment of circadian rhythms and suggests conserved roles for peroxiredoxins in endogenous rhythms. While yeasts lack dedicated photoreceptors, they nonetheless possess metabolic rhythms responsive to light. Here the authors find that light signalling in budding yeast involves the production of H2O2, which in turn regulates protein kinase A through a peroxiredoxin-thioredoxin redox relay.
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Affiliation(s)
- Kristofer Bodvard
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, S-413 90 Göteborg, Sweden.,Department of Physics, Chalmers University of Technology, S-412 96 Göteborg, Sweden
| | - Ken Peeters
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, S-413 90 Göteborg, Sweden
| | - Friederike Roger
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, S-413 90 Göteborg, Sweden
| | - Natalie Romanov
- Mass Spectrometry Facility, Max F. Perutz Laboratories, University of Vienna, Dr Bohrgasse 9, A-1030 Vienna, Austria
| | - Aeid Igbaria
- Oxidative Stress and Cancer, SBIGEM, iBiTec-S, FRE3377 CEA-CNRS-Université Paris-Sud, CEA-Saclay, bat 142 F-91191 Gif Sur Yvette, France
| | - Niek Welkenhuysen
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, S-413 90 Göteborg, Sweden.,Hohmann Lab, Department of Biology and Biological Engineering, Chalmers University of Technology, S-412 96 Göteborg, Sweden
| | - Gaël Palais
- Oxidative Stress and Cancer, SBIGEM, iBiTec-S, FRE3377 CEA-CNRS-Université Paris-Sud, CEA-Saclay, bat 142 F-91191 Gif Sur Yvette, France
| | - Wolfgang Reiter
- Department of Biochemistry, Max F. Perutz Laboratories, University of Vienna, Dr Bohrgasse 9, A-1030 Vienna, Austria
| | - Michel B Toledano
- Oxidative Stress and Cancer, SBIGEM, iBiTec-S, FRE3377 CEA-CNRS-Université Paris-Sud, CEA-Saclay, bat 142 F-91191 Gif Sur Yvette, France
| | - Mikael Käll
- Department of Physics, Chalmers University of Technology, S-412 96 Göteborg, Sweden
| | - Mikael Molin
- Department of Chemistry and Molecular Biology, University of Gothenburg, Box 462, S-413 90 Göteborg, Sweden
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18
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Kim BH, Choi MS, Lee HG, Lee SH, Noh KH, Kwon S, Jeong AJ, Lee H, Yi EH, Park JY, Lee J, Joo EY, Ye SK. Photoprotective Potential of Penta-O-Galloyl-β-DGlucose by Targeting NF-κB and MAPK Signaling in UVB Radiation-Induced Human Dermal Fibroblasts and Mouse Skin. Mol Cells 2015; 38:982-90. [PMID: 26537189 PMCID: PMC4673413 DOI: 10.14348/molcells.2015.0169] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Revised: 08/21/2015] [Accepted: 09/04/2015] [Indexed: 01/01/2023] Open
Abstract
Exposure of the skin to ultraviolet radiation can cause skin damage with various pathological changes including inflammation. In the present study, we identified the skin-protective activity of 1,2,3,4,6-penta-O-galloyl-β-D-glucose (pentagalloyl glucose, PGG) in ultraviolet B (UVB) radiation-induced human dermal fibroblasts and mouse skin. PGG exhibited antioxidant activity with regard to intracellular reactive oxygen species (ROS) generation as well as ROS and reactive nitrogen species (RNS) scavenging. Furthermore, PGG exhibited anti-inflammatory activity, inhibiting the activation of nuclear factor-kappaB (NF-κB) and mitogen-activated protein kinase (MAPK) signaling, resulting in inhibition of the expression of pro-inflammatory mediators. Topical application of PGG followed by chronic exposure to UVB radiation in the dorsal skin of hairless mice resulted in a significant decrease in the progression of inflammatory skin damages, leading to inhibited activation of NF-κB signaling and expression of pro-inflammatory mediators. The present study demonstrated that PGG protected from skin damage induced by UVB radiation, and thus, may be a potential candidate for the prevention of environmental stimuli-induced inflammatory skin damage.
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Affiliation(s)
- Byung-Hak Kim
- Department of Pharmacology, Seoul National University College of Medicine, Seoul 110-799,
Korea
- Biomedical Science Project (BK21 PLUS), Seoul National University College of Medicine, Seoul 110-799,
Korea
| | - Mi Sun Choi
- Department of Herbal Biotechnology, Daegu Haany University, Gyeongsan 38610,
Korea
| | - Hyun Gyu Lee
- Department of Microbiology and Immunology, Yonsei University College of Medicine, Seoul 03722,
Korea
| | - Song-Hee Lee
- Department of Pharmacology, Seoul National University College of Medicine, Seoul 110-799,
Korea
| | - Kum Hee Noh
- Department of Pharmacology, Seoul National University College of Medicine, Seoul 110-799,
Korea
| | - Sunho Kwon
- Department of Pharmacology, Seoul National University College of Medicine, Seoul 110-799,
Korea
| | - Ae Jin Jeong
- Department of Pharmacology, Seoul National University College of Medicine, Seoul 110-799,
Korea
| | - Haeri Lee
- Department of Pharmacology, Seoul National University College of Medicine, Seoul 110-799,
Korea
| | - Eun Hee Yi
- Department of Pharmacology, Seoul National University College of Medicine, Seoul 110-799,
Korea
- Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul 110-799,
Korea
| | - Jung Youl Park
- Industry-Academic Cooperation Foundation, Hanbat National University, Daejeon 305-719,
Korea
| | - Jintae Lee
- Department of Cosmeceutical Science, Daegu Haany University, Gyeongsan 38610,
Korea
| | - Eun Young Joo
- Department of Herbal Biotechnology, Daegu Haany University, Gyeongsan 38610,
Korea
| | - Sang-Kyu Ye
- Department of Pharmacology, Seoul National University College of Medicine, Seoul 110-799,
Korea
- Biomedical Science Project (BK21 PLUS), Seoul National University College of Medicine, Seoul 110-799,
Korea
- Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Seoul 110-799,
Korea
- Neuro-Immune Information Storage Network Research Center, Seoul National University College of Medicine, Seoul 110-799,
Korea
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19
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Benković ET, Kreft S. Fagopyrins and Protofagopyrins: Detection, Analysis, and Potential Phototoxicity in Buckwheat. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2015; 63:5715-5724. [PMID: 26024291 DOI: 10.1021/acs.jafc.5b01163] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Buckwheat contains many healthy nutrients, and its consumption is therefore increasing. Buckwheat also contains fluorescent phototoxic fagopyrins. A systematic review of fagopyrins and the phototoxicity of buckwheat found that reliable quantitative data on fagopyrin toxicity are not yet available. Generally, buckwheat seeds, flour, and teas are safe in normal amounts. Diets extensively composed of buckwheat sprouts, herbs, and particularly flowers or of fagopyrin-rich buckwheat extracts may cause fagopyrism. A reference standard is needed, as it would enable the accurate evaluation of fagopyrin content in buckwheat products and would allow proper testing of their as yet unknown physical, chemical, and biological characteristics.
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Affiliation(s)
- Eva Tavčar Benković
- Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, 1000 Ljubljana, Slovenia
| | - Samo Kreft
- Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, 1000 Ljubljana, Slovenia
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20
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Effect of Ultraviolet-A (UV-A) and Ultraviolet-C (UV-C) Light on Mechanical Properties of Oyster Mushrooms during Growth. JOURNAL OF BIOPHYSICS 2015; 2014:687028. [PMID: 25580117 PMCID: PMC4279123 DOI: 10.1155/2014/687028] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/14/2014] [Accepted: 11/27/2014] [Indexed: 11/18/2022]
Abstract
This study investigated the effects of ultraviolet-A (UV-A) and ultraviolet-C (UV-C) light on the mechanical properties in oyster mushrooms during the growth. Experiments were carried out with irradiation of the mushrooms with UV-A (365 nm) and UV-C (254 nm) light during growth. The exposure time ranged from 10 minutes to 60 minutes at intervals of 10 minutes and irradiation was done for three days. The samples for experimental studies were cut into cylindrical shapes of diameter 12.50 mm and thickness 3.00 mm. The storage modulus, loss modulus, and loss factor of the irradiated samples and control samples were determined for both UV bands and there was a significant difference between the storage modulus, loss modulus, and loss factor of the irradiated samples by both UV bands with reference to the control sample, P < 0.05. UV-C light irradiated samples had higher loss modulus and loss factor but low storage modulus as temperature increased from 35 to 100°C with respect to the control sample while UV-A light irradiated samples had lower loss modulus, low loss factor, and higher storage modulus than UV-C irradiated samples.
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21
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Chang C, Murzaku EC, Penn L, Abbasi NR, Davis PD, Berwick M, Polsky D. More skin, more sun, more tan, more melanoma. Am J Public Health 2014; 104:e92-9. [PMID: 25211764 DOI: 10.2105/ajph.2014.302185] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Although personal melanoma risk factors are well established, the contribution of socioeconomic factors, including clothing styles, social norms, medical paradigms, perceptions of tanned skin, economic trends, and travel patterns, to melanoma incidence has not been fully explored. We analyzed artwork, advertisements, fashion trends, and data regarding leisure-time activities to estimate historical changes in UV skin exposure. We used data from national cancer registries to compare melanoma incidence rates with estimated skin exposure and found that they rose in parallel. Although firm conclusions about melanoma causation cannot be made in an analysis such as this, we provide a cross-disciplinary, historical framework in which to consider public health and educational measures that may ultimately help reverse melanoma incidence trends.
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Affiliation(s)
- Caroline Chang
- Caroline Chang, Era Caterina Murzaku, Lauren Penn, Naheed R. Abbasi, and David Polsky are with The Ronald O. Perelman Department of Dermatology, New York University School of Medicine, New York, NY. Paula D. Davis is with Bucknell University, Lewisburg, PA. Marianne Berwick is with University of New Mexico Cancer Center, Albuquerque
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22
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Avila Acevedo JG, Espinosa González AM, Campos DMDMY, Benitez Flores JDC, Delgado TH, Maya SF, Contreras JC, López JLM, García Bores AM. Photoprotection of Buddleja cordata extract against UVB-induced skin damage in SKH-1 hairless mice. Altern Ther Health Med 2014; 14:281. [PMID: 25086781 PMCID: PMC4131034 DOI: 10.1186/1472-6882-14-281] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Accepted: 07/23/2014] [Indexed: 11/24/2022]
Abstract
Background In recent years, there has been considerable interest in using botanical agents to prevent skin damage resulting from solar UV-irradiation. Buddleja cordata is a plant that is known as “tepozan”. Some people in Mexico use the leaves of this plant to treat tumours, abscesses, sores and burns. The purpose of this study is to investigate the photoprotective properties of Buddleja cordata methanolic extract (BCME) against UVB-induced skin damage in SKH-1 hairless mice at the macroscopic and histological levels. Methods BCME was characterised to determine its spectroscopic, chromatographic and antioxidant (DPPH, superoxide and hydroxyl radicals) properties. To conduct the photoprotection studies, BCME was applied topically to the skin of SKH-1 mice before acute exposure to UVB for 10 minutes. The murine skin samples were used for macroscopic and histological studies to assess tissue damage. Penetration of active components of BCME into stratum corneum on the dorsal area of mice was investigated in vivo by the tape stripping method. Moreover, genotoxicity of BCME was evaluated in a Vicia faba cell root micronucleus model. Results BCME displayed absorbance over the entire UVB spectrum, and its principal components included verbascoside and linarin. BCME exhibited antioxidant activity and significantly scavenged hydroxyl radicals. BCME reduced erythema, sunburn cell production, vessel congestion and epidermal thickening of UVB irradiated mouse skin. BCME penetrate the skin of mice. BCME did not exhibit genotoxic activity in the micronucleus test. Conclusion The topical administration of BCME protected against acute UVB-induced damage in mouse SKH-1 skin, and our results suggest that BCME may potentially prevent photodamage.
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23
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Gupta A, Avci P, Dai T, Huang YY, Hamblin MR. Ultraviolet Radiation in Wound Care: Sterilization and Stimulation. Adv Wound Care (New Rochelle) 2013; 2:422-437. [PMID: 24527357 DOI: 10.1089/wound.2012.0366] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2012] [Indexed: 01/09/2023] Open
Abstract
SIGNIFICANCE Wound care is an important area of medicine considering the increasing age of the population who may have diverse comorbidities. Light-based technology comprises a varied set of modalities of increasing relevance to wound care. While low-level laser (or light) therapy and photodynamic therapy both have wide applications in wound care, this review will concentrate on the use of ultraviolet (UV) radiation. RECENT ADVANCES UVC (200-280 nm) is highly antimicrobial and can be directly applied to acute wound infections to kill pathogens without unacceptable damage to host tissue. UVC is already widely applied for sterilization of inanimate objects. UVB (280-315 nm) has been directly applied to the wounded tissue to stimulate wound healing, and has been widely used as extracorporeal UV radiation of blood to stimulate the immune system. UVA (315-400 nm) has distinct effects on cell signaling, but has not yet been widely applied to wound care. CRITICAL ISSUES Penetration of UV light into tissue is limited and optical technology may be employed to extend this limit. UVC and UVB can damage DNA in host cells and this risk must be balanced against beneficial effects. Chronic exposure to UV can be carcinogenic and this must be considered in planning treatments. FUTURE DIRECTIONS New high-technology UV sources, such as light-emitting diodes, lasers, and microwave-generated UV plasma are becoming available for biomedical applications. Further study of cellular signaling that occurs after UV exposure of tissue will allow the benefits in wound healing to be better defined.
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Affiliation(s)
- Asheesh Gupta
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts
- Department of Dermatology, Harvard Medical School, Boston, Massachusetts
- Defense Institute of Physiology and Allied Sciences (DIPAS), Delhi, India
| | - Pinar Avci
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts
| | - Tianhong Dai
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts
- Department of Dermatology, Harvard Medical School, Boston, Massachusetts
| | - Ying-Ying Huang
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts
- Department of Dermatology, Harvard Medical School, Boston, Massachusetts
- Department of Pathology, Guangxi Medical University, Nanning, China
| | - Michael R. Hamblin
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, Massachusetts
- Department of Dermatology, Harvard Medical School, Boston, Massachusetts
- Harvard–MIT Division of Health Sciences and Technology, Cambridge, Massachusetts
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24
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Ruiz-González C, Simó R, Sommaruga R, Gasol JM. Away from darkness: a review on the effects of solar radiation on heterotrophic bacterioplankton activity. Front Microbiol 2013; 4:131. [PMID: 23734148 PMCID: PMC3661993 DOI: 10.3389/fmicb.2013.00131] [Citation(s) in RCA: 74] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2013] [Accepted: 05/06/2013] [Indexed: 12/22/2022] Open
Abstract
Heterotrophic bacterioplankton are main consumers of dissolved organic matter (OM) in aquatic ecosystems, including the sunlit upper layers of the ocean and freshwater bodies. Their well-known sensitivity to ultraviolet radiation (UVR), together with some recently discovered mechanisms bacteria have evolved to benefit from photosynthetically available radiation (PAR), suggest that natural sunlight plays a relevant, yet difficult to predict role in modulating bacterial biogeochemical functions in aquatic ecosystems. Three decades of experimental work assessing the effects of sunlight on natural bacterial heterotrophic activity reveal responses ranging from high stimulation to total inhibition. In this review, we compile the existing studies on the topic and discuss the potential causes underlying these contrasting results, with special emphasis on the largely overlooked influences of the community composition and the previous light exposure conditions, as well as the different temporal and spatial scales at which exposure to solar radiation fluctuates. These intricate sunlight-bacteria interactions have implications for our understanding of carbon fluxes in aquatic systems, yet further research is necessary before we can accurately evaluate or predict the consequences of increasing surface UVR levels associated with global change.
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Affiliation(s)
- Clara Ruiz-González
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar, CSICBarcelona, Spain
- Département des Sciences Biologiques, Université du Québéc à MontréalMontréal, QC, Canada
| | - Rafel Simó
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar, CSICBarcelona, Spain
| | - Ruben Sommaruga
- Laboratory of Aquatic Photobiology and Plankton Ecology, Institute of Ecology, University of InnsbruckInnsbruck, Austria
| | - Josep M. Gasol
- Department of Marine Biology and Oceanography, Institut de Ciències del Mar, CSICBarcelona, Spain
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25
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Dai T, Kharkwal GB, Zhao J, St Denis TG, Wu Q, Xia Y, Huang L, Sharma SK, d'Enfert C, Hamblin MR. Ultraviolet-C light for treatment of Candida albicans burn infection in mice. Photochem Photobiol 2011; 87:342-9. [PMID: 21208209 DOI: 10.1111/j.1751-1097.2011.00886.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Burn patients are at high risk of invasive fungal infections, which are a leading cause of morbidity, mortality, and related expense exacerbated by the emergence of drug resistant fungal strains. In this study, we investigated the use of UVC light (254 nm) for the treatment of yeast Candida albicans infection in mouse third degree burns. In vitro studies demonstrated that UVC could selectively kill the pathogenic C. albicans compared with a normal mouse keratinocyte cell line in a light exposure dependent manner. A mouse model of chronic C. albicans infection in non-lethal third degree burns was developed. The C. albicans strain was stably transformed with a version of the Gaussia princeps luciferase gene that allowed real-time bioluminescence imaging of the progression of C. albicans infection. UVC treatment with a single exposure carried out on day 0 (30 min postinfection) gave an average 2.16-log(10)-unit (99.2%) loss of fungal luminescence when 2.92 J cm(-2) UVC had been delivered, while UVC 24 h postinfection gave 1.94-log(10)-unit (95.8%) reduction of fungal luminescence after 6.48 J cm(-2). Statistical analysis demonstrated that UVC treatment carried out on both day 0 and day 1 significantly reduced the fungal bioburden of infected burns. UVC was found to be superior to a topical antifungal drug, nystatin cream. UVC was tested on normal mouse skin and no gross damage was observed 24 h after 6.48 J cm(-2). DNA lesions (cyclobutane pyrimidine dimers) were observed by immunofluorescence in normal mouse skin immediately after a 6.48 J cm(-2) UVC exposure, but the lesions were extensively repaired at 24 h after UVC exposure.
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Affiliation(s)
- Tianhong Dai
- Wellman Center for Photomedicine, Massachusetts General Hospital, Boston, MA, USA
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26
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Xia L, Lenaghan SC, Zhang M, Zhang Z, Li Q. Naturally occurring nanoparticles from English ivy: an alternative to metal-based nanoparticles for UV protection. J Nanobiotechnology 2010; 8:12. [PMID: 20534157 PMCID: PMC2893082 DOI: 10.1186/1477-3155-8-12] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2010] [Accepted: 06/09/2010] [Indexed: 11/25/2022] Open
Abstract
Background Over the last decade safety concerns have arisen about the use of metal-based nanoparticles in the cosmetics field. Metal-based nanoparticles have been linked to both environmental and animal toxicity in a variety of studies. Perhaps the greatest concern involves the large amounts of TiO2 nanoparticles that are used in commercial sunscreens. As an alternative to using these potentially hazardous metal-based nanoparticles, we have isolated organic nanoparticles from English ivy (Hedera helix). In this study, ivy nanoparticles were evaluated for their potential use in sunscreens based on four criteria: 1) ability to absorb and scatter ultraviolet light, 2) toxicity to mammalian cells, 3) biodegradability, and 4) potential for diffusion through skin. Results Purified ivy nanoparticles were first tested for their UV protective effects using a standard spectrophotometric assay. Next the cell toxicity of the ivy nanoparticles was compared to TiO2 nanoparticles using HeLa cells. The biodegradability of these nanoparticles was also determined through several digestion techniques. Finally, a mathematical model was developed to determine the potential for ivy nanoparticles to penetrate through human skin. The results indicated that the ivy nanoparticles were more efficient in blocking UV light, less toxic to mammalian cells, easily biodegradable, and had a limited potential to penetrate through human skin. When compared to TiO2 nanoparticles, the ivy nanoparticles showed decreased cell toxicity, and were easily degradable, indicating that they provided a safer alternative to these nanoparticles. Conclusions With the data collected from this study, we have demonstrated the great potential of ivy nanoparticles as a sunscreen protective agent, and their increased safety over commonly used metal oxide nanoparticles.
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Affiliation(s)
- Lijin Xia
- Department of Mechanical, Aerospace and Biomedical Engineering, University of Tennessee, Knoxville, TN, 37996, USA.
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27
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Abstract
Public health concerns such as multi- and extensive drug-resistant tuberculosis, bioterrorism, pandemic influenza, and severe acute respiratory syndrome have intensified efforts to prevent transmission of infections that are completely or partially airborne using environmental controls. One such control, ultraviolet germicidal irradiation (UVGI), has received renewed interest after decades of underutilization and neglect. With renewed interest, however, come renewed questions, especially regarding efficacy and safety. There is a long history of investigations concluding that, if used properly, UVGI can be safe and highly effective in disinfecting the air, thereby preventing transmission of a variety of airborne infections. Despite this long history, many infection control professionals are not familiar with the history of UVGI and how it has, and has not, been used safely and effectively. This article reviews that history of UVGI for air disinfection, starting with its biological basis, moving to its application in the real world, and ending with its current status.
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Affiliation(s)
- Nicholas G Reed
- U.S. Army Center for Health Promotion and Preventive Medicine, Laser/Optical Radiation Program, Aberdeen Proving Ground, MD, USA.
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Abstract
Throughout history, humankind has won the battle against deadly diseases, including small pox and polio, by defeating them through prevention. Cancer prevention is a global priority, but studying history suggests that the journey towards achieving this goal is difficult and full of detours and roadblocks. Epidemiology and clinical evidence clearly indicate that specific genetic, environmental and behavioural factors are associated with an increased risk for cancer development. What can we learn from the past that is applicable to the reality of successful cancer prevention?
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Affiliation(s)
- Ann M Bode
- The Hormel Institute, University of Minnesota, 801 16th Ave NE, Austin, Minnesota 55912, USA
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29
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Abstract
The H1N1 "Spanish flu" outbreak of 1918-1919 was the most devastating pandemic on record, killing between 50 million and 100 million people. Should the next influenza pandemic prove equally virulent, there could be more than 300 million deaths globally. The conventional view is that little could have been done to prevent the H1N1 virus from spreading or to treat those infected; however, there is evidence to the contrary. Records from an "open-air" hospital in Boston, Massachusetts, suggest that some patients and staff were spared the worst of the outbreak. A combination of fresh air, sunlight, scrupulous standards of hygiene, and reusable face masks appears to have substantially reduced deaths among some patients and infections among medical staff. We argue that temporary hospitals should be a priority in emergency planning. Equally, other measures adopted during the 1918 pandemic merit more attention than they currently receive.
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Affiliation(s)
- Richard A Hobday
- Department of Architectural Studies, University of Wales Institute, Cardiff, Llandaff Campus, Western Avenue, Cardiff, CF5 2YB, United Kingdom.
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30
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Edwards SL, Charlie NK, Milfort MC, Brown BS, Gravlin CN, Knecht JE, Miller KG. A novel molecular solution for ultraviolet light detection in Caenorhabditis elegans. PLoS Biol 2008; 6:e198. [PMID: 18687026 PMCID: PMC2494560 DOI: 10.1371/journal.pbio.0060198] [Citation(s) in RCA: 214] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2008] [Accepted: 07/09/2008] [Indexed: 11/19/2022] Open
Abstract
For many organisms the ability to transduce light into cellular signals is crucial for survival. Light stimulates DNA repair and metabolism changes in bacteria, avoidance responses in single-cell organisms, attraction responses in plants, and both visual and nonvisual perception in animals. Despite these widely differing responses, in all of nature there are only six known families of proteins that can transduce light. Although the roundworm Caenorhabditis elegans has none of the known light transduction systems, we show here that C. elegans strongly accelerates its locomotion in response to blue or shorter wavelengths of light, with maximal responsiveness to ultraviolet light. Our data suggest that C. elegans uses this light response to escape the lethal doses of sunlight that permeate its habitat. Short-wavelength light drives locomotion by bypassing two critical signals, cyclic adenosine monophosphate (cAMP) and diacylglycerol (DAG), that neurons use to shape and control behaviors. C. elegans mutants lacking these signals are paralyzed and unresponsive to harsh physical stimuli in ambient light, but short-wavelength light rapidly rescues their paralysis and restores normal levels of coordinated locomotion. This light response is mediated by LITE-1, a novel ultraviolet light receptor that acts in neurons and is a member of the invertebrate Gustatory receptor (Gr) family. Heterologous expression of the receptor in muscle cells is sufficient to confer light responsiveness on cells that are normally unresponsive to light. Our results reveal a novel molecular solution for ultraviolet light detection and an unusual sensory modality in C. elegans that is unlike any previously described light response in any organism.
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Affiliation(s)
- Stacey L Edwards
- Genetic Models of Disease Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, United States of America
| | - Nicole K Charlie
- Genetic Models of Disease Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, United States of America
| | - Marie C Milfort
- Genetic Models of Disease Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, United States of America
| | - Brandon S Brown
- Genetic Models of Disease Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, United States of America
| | - Christen N Gravlin
- Genetic Models of Disease Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, United States of America
| | - Jamie E Knecht
- Genetic Models of Disease Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, United States of America
| | - Kenneth G Miller
- Genetic Models of Disease Program, Oklahoma Medical Research Foundation, Oklahoma City, Oklahoma, United States of America
- * To whom correspondence should be addressed. E-mail:
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31
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Callegari AJ, Kelly TJ. UV irradiation induces a postreplication DNA damage checkpoint. Proc Natl Acad Sci U S A 2006; 103:15877-82. [PMID: 17043220 PMCID: PMC1613229 DOI: 10.1073/pnas.0607343103] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Eukaryotic cells irradiated with high doses of UV exhibit cell-cycle responses referred to as G(1)/S, intraS, and G(2)/M checkpoints. After a moderate UV dose that approximates sunlight exposure and is lethal to fission yeast checkpoint mutants, we found unexpectedly that these cell-cycle responses do not occur. Instead, cells at all stages of the cell cycle carry lesions into S phase and delay cell-cycle progression for hours after the completion of bulk DNA synthesis. Both DNA replication and the checkpoint kinase, Chk1, are required to generate this cell-cycle response. UV-irradiation of Deltachk1 cells causes chromosome damage and loss of viability only after cells have replicated irradiated DNA and entered mitosis. These data suggest that an important physiological role of the cell-cycle response to UV is to provide time for postreplication repair.
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Affiliation(s)
- A. John Callegari
- *Program in Molecular Biology, Memorial Sloan–Kettering Cancer Center, New York, NY 10021; and
- Cellular and Molecular Medicine Program, Johns Hopkins University School of Medicine, Baltimore, MD 21205
| | - Thomas J. Kelly
- *Program in Molecular Biology, Memorial Sloan–Kettering Cancer Center, New York, NY 10021; and
- To whom correspondence should be addressed. E-mail:
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32
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Wokosin DL, Loughrey CM, Smith GL. Characterization of a range of fura dyes with two-photon excitation. Biophys J 2004; 86:1726-38. [PMID: 14990500 PMCID: PMC1304008 DOI: 10.1016/s0006-3495(04)74241-1] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Two-photon excitation (TPE) spectra of Fura-2, -4F, -6F, -FF, and Furaptra were characterized using a tunable (750-850 nM) ultra-short pulse laser. Two-photon fluorescence of these dyes was studied in free solution and in the cytosol of isolated rabbit ventricular cardiomyocytes. The TPE spectra of the Ca(2+)-free and Ca(2+)-bound forms of the dyes were measured in free solution and expressed in terms of the two-photon fluorescence cross section (Goppert-Meyer units). The Fura dyes displayed the same Ca(2+)-free TPE spectrum in the intracellular volume of permeabilized and intact cardiomyocytes. Fluorescence measurements over a range of laser powers confirmed the TPE of both Ca(2+)-free and Ca(2+)-bound forms of the dyes. Single-wavelength excitation at 810 nM was used to determine the effective dissociation constants (K(eff)) and dynamic ranges (R(f)) of Fura-2, -4F, -6F, -FF, and Furaptra dyes (K(eff) = 181 +/- 52 nM, 1.16 +/- 0.016 micro M, 5.18 +/- 0.3 micro M, 19.2 +/- 1 micro M, and 58.5 +/- 2 micro M; and R(f) = 22.4 +/- 3.8, 12.2 +/- 0.34, 6.3 +/- 0.17, 16.1 +/- 2.8, and 25.4 +/- 4, respectively). Single-wavelength excitation of intracellular Fura-4F resolved diastolic and peak [Ca(2+)] in isolated stimulated cardiomyocytes after calibration of the intracellular signal using reversible exposure to low (100 micro M) extracellular [Ca(2+)]. Furthermore, TPE of Fura-4F allowed continuous, long-term (5-10 min) Ca(2+) imaging in ventricular cardiomyocytes using laser-scanning microscopy without significant cellular photodamage or photobleaching of the dye.
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Affiliation(s)
- D L Wokosin
- Centre for Biophotonics, Strathclyde University, Glasgow, United Kingdom
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