Science.gov

Sample records for cultura da uva

  1. Solar UVA exposures

    NASA Astrophysics Data System (ADS)

    Parisi, Alfio V.; Kimlin, Michael G.

    2005-08-01

    Exposures to UVA radiation (320 - 400 nm) have been linked to increasing the risk of skin cancer, premature skin photoageing and skin wrinkling. The relative proportion of the UVA irradiances in the solar spectrum changes with time of day and season. Material such as window glass found in offices, homes and motor vehicles acts as a barrier to the shorter solar UVB wavelengths (280 - 320 nm) and transmits some of the longer UVA wavelengths (dependent on the type of glass). As a result, the spectrum of the filtered UV transmitted through the material may be substantially different from that of the unfiltered solar UV spectrum. This results in a change in the relative ratio of UVA to UVB irradiances and a consequent change in the biologically damaging UV exposures. For these environments where the UVB wavelengths have been removed and the UVA wavelengths are still present, it is necessary to consider the erythemal irradiances due to these UVA wavelengths only. This paper investigates the times taken for an exposure of 1 SED (standard erythemal dose) due to the UVA wavelengths.

  2. The biological effects of UVA radiation

    SciTech Connect

    Urbach, F.; Gange, R.

    1986-01-01

    Interest in the biological effects of longwave radiation has increased dramatically in the last few years. The contributors to this state of the art volume discuss the most current knowledge of biological effects of UVA and provide guidelines regarding acceptable human exposure to this type of radiation. Contents include: historical aspects of UVA effects; mechanisms of UVA photosensitization; photorecovery by UVA; photoaugmentation of UVB effects by UVA; effects of UVA radiation on tissues of the eye; new UVA sunscreen; and recommendations for future research and possible actions.

  3. Cultura Revisited

    ERIC Educational Resources Information Center

    Furstenberg, Gilberte; English, Kathryn

    2016-01-01

    Two of the original authors of "Giving a Virtual Voice to the Silent Language of Culture: The Cultura Project", published in "Language Learning & Technology" in 2001, look back on the origin of the Cultura project, its goals, and the approach and materials used. Their commentary then focuses on the features and the…

  4. UVA photoprotective properties of an artificial carotenylflavonoid hybrid molecule.

    PubMed

    Hundsdörfer, Claas; Stahl, Wilhelm; Müller, Thomas J J; De Spirt, Silke

    2012-08-20

    Carotenoids and flavonoids represent two classes of natural antioxidants, a biological activity, which is determined by their chemical structure. To combine their antioxidant properties, a dual functional carotenylflavonoid hybrid molecule was synthesized. The antioxidant activity of this compound was tested in human dermal fibroblasts exposed to UVA irradiation. Test parameters were hemeoxygenase-1 (HO-1) expression, malondialdehyde (MDA), and reactive oxygen species (ROS) formation and cell viability. For comparison, the substructure components of the carotenylflavonoid, 4-hydroxyflavone and 11'-apo-β-carotenylbenzene, were also tested. Incubation of cells with the carotenylflavonoid and 11'-apo-β-carotenylbenzene attenuated UVA-induced HO-1 expression. In the MDA assay, the carotenylflavonoid and 11'-apo-β-carotenylbenzene were moderately effective at low concentrations. At higher concentrations, the compound provoked an increase of MDA, which was confirmed by the H(2)DCF-DA assay measuring ROS formation. 4-Hydroxyflavone moderately inhibited the formation of MDA at all levels that were tested. The study showed that the carotenylflavonoid counteracts UVA-induced HO-1 expression. However, a photoprotection against lipid oxidation, ROS formation, and cell toxicity could not be proven in the experimental setting.

  5. UVA Generates Pyrimidine Dimers in DNA Directly

    PubMed Central

    Jiang, Yong; Rabbi, Mahir; Kim, Minkyu; Ke, Changhong; Lee, Whasil; Clark, Robert L.; Mieczkowski, Piotr A.; Marszalek, Piotr E.

    2009-01-01

    There is increasing evidence that UVA radiation, which makes up ∼95% of the solar UV light reaching the Earth's surface and is also commonly used for cosmetic purposes, is genotoxic. However, in contrast to UVC and UVB, the mechanisms by which UVA produces various DNA lesions are still unclear. In addition, the relative amounts of various types of UVA lesions and their mutagenic significance are also a subject of debate. Here, we exploit atomic force microscopy (AFM) imaging of individual DNA molecules, alone and in complexes with a suite of DNA repair enzymes and antibodies, to directly quantify UVA damage and reexamine its basic mechanisms at a single-molecule level. By combining the activity of endonuclease IV and T4 endonuclease V on highly purified and UVA-irradiated pUC18 plasmids, we show by direct AFM imaging that UVA produces a significant amount of abasic sites and cyclobutane pyrimidine dimers (CPDs). However, we find that only ∼60% of the T4 endonuclease V-sensitive sites, which are commonly counted as CPDs, are true CPDs; the other 40% are abasic sites. Most importantly, our results obtained by AFM imaging of highly purified native and synthetic DNA using T4 endonuclease V, photolyase, and anti-CPD antibodies strongly suggest that CPDs are produced by UVA directly. Thus, our observations contradict the predominant view that as-yet-unidentified photosensitizers are required to transfer the energy of UVA to DNA to produce CPDs. Our results may help to resolve the long-standing controversy about the origin of UVA-produced CPDs in DNA. PMID:19186150

  6. The influence of ventral UVA exposure on subsequent tumorigenesis in mice by UVA or UVB irradiation.

    PubMed

    Kelfkens, G; de Gruijl, F R; van der Leun, J C

    1992-11-01

    Exposure to ultraviolet-B radiation (UVB: 280-315 nm) can result in a decreased immune response. This immune suppression can be restricted to the exposed skin site (local immune suppression) but may also be systemic. To investigate whether ultraviolet-A radiation (UVA: 315-400 nm) could also exert such a systemic effect, we performed the present investigation. The study consisted of two parts. Experiment I: 24 albino hairless mice (SKH:HRI) were ventrally exposed to UVA radiation for 300 days (glass-filtered Philips TLK09 fluorescent tubes, daily dose: 350 kJ/m2), while 24 control mice were left unexposed. After this period the control animals were still tumour free, but 60% of the exposed animals had developed abdominal tumours. Subsequently ventral exposures were stopped and both groups were dorsally exposed to identical UVB regimens (Westinghouse FS40, daily dose: 900 J/m2). Experiment II: this was virtually the same as experiment I, but here the mice were dorsally exposed to UVA radiation (glass-filtered Philips TLK09, daily dose: 290 kJ/m2) instead of UVB radiation. If we look at all tumours induced dorsally, we find no significant influence of pre-exposures to UVA radiation. This holds for dorsal UVB as well as for dorsal UVA exposures. In contrast to UVB, however, the UVA radiation induced many papillomas. Excluding the papillomas from the analysis we find that the induction of non-papillomas (mainly squamous cell carcinomas) under dorsal UVA exposure, is slightly enhanced in the ventrally pre-exposed group (difference significant at the P < 0.05 level). This suggests that UVA radiation induced only a weak systemic effect. Ventral UVA pre-exposure did not appear to affect dorsal skin irritation as expressed by scratch marks. The induction period for hyperkeratosis, however, was significantly shortened by the ventral UVA pre-exposure; this applied to dorsal UVB as well as dorsal UVA exposures.

  7. UVA-induced cyclobutane pyrimidine dimers in DNA: a direct photochemical mechanism?

    PubMed

    Mouret, Stéphane; Philippe, Coralie; Gracia-Chantegrel, Jocelyne; Banyasz, Akos; Karpati, Szilvia; Markovitsi, Dimitra; Douki, Thierry

    2010-04-07

    The carcinogenic action of UVA radiation is commonly attributed to DNA oxidation mediated by endogenous photosensitisers. Yet, it was recently shown that cyclobutane pyrimidine dimers (CPD), well known for their involvement in UVB genotoxicity, are produced in larger yield than oxidative lesions in UVA-irradiated cells and skin. In the present work, we gathered mechanistic information on this photoreaction by comparing formation of all possible bipyrimidine photoproducts upon UVA irradiation of cells, purified genomic DNA and dA(20):dT(20) oligonucleotide duplex. We observed that the distribution of photoproducts, characterized by the sole formation of CPD and the absence of (6-4) photoproducts was similar in the three types of samples. The CPD involving two thymines represented 90% of the amount of photoproducts. Moreover, the yields of formation of the DNA lesions were similar in cells and isolated DNA. In addition, the effect of the wavelength of the incident photons was found to be the same in isolated DNA and cells. This set of data shows that UVA-induced cyclobutane pyrimidine dimers are formed via a direct photochemical mechanism, without mediation of a cellular photosensitiser. This is possible because the double-stranded structure increases the capacity of DNA bases to absorb UVA photons, as evidenced in the case of the oligomer dA(20):dT(20). These results emphasize the need to consider UVA in the carcinogenic effects of sunlight. An efficient photoprotection is needed that can only be complete by completely blocking incident photons, rather than by systemic approaches such as antioxidant supplementation.

  8. In vitro UV-A protection factor (PF-UVA) of organic and inorganic sunscreens.

    PubMed

    Couteau, C; El-Boury, S; Paparis, E; Sébille-Rivain, V; Coiffard, L J M

    2009-01-01

    The objective of this research was to evaluate the efficacy of various sunscreen agents incorporated into an O/W emulsion. Within the scope of this study only an in vitro method was used. According to selected filter UVA, we can obtain more or less effective creams. With the seven available filters, we can cover a range of values between 2 and 12. In addition to these seven filters absorbing in UVA range, variously coated titanium dioxide and zinc oxide were tested as well. So it appears that the best organic UVA filter is anisotriazine at 10% (PF-UVA = 11.82). Its effectiveness is comparable with that of the titanium dioxide forms used at 25%. Photostability in Suntest showed that the more photostable UVA-filters are the benzophenones.

  9. Diversity of biological effects induced by longwave UVA rays (UVA1) in reconstructed skin.

    PubMed

    Marionnet, Claire; Pierrard, Cécile; Golebiewski, Christelle; Bernerd, Françoise

    2014-01-01

    Despite their preponderance amongst the ultraviolet (UV) range received on Earth, the biological impacts of longwave UVA1 rays (340-400 nm) upon human skin have not been investigated so thoroughly. Nevertheless, recent studies have proven their harmful effects and involvement in carcinogenesis and immunosuppression. In this work, an in vitro reconstructed human skin model was used for exploring the effects of UVA1 at molecular, cellular and tissue levels. A biological impact of UVA1 throughout the whole reconstructed skin structure could be evidenced, from morphology to gene expression analysis. UVA1 induced immediate injuries such as generation of reactive oxygen species and thymine dimers DNA damage, accumulating preferentially in dermal fibroblasts and basal keratinocytes, followed by significant cellular alterations, such as fibroblast apoptosis and lipid peroxidation. The full genome transcriptomic study showed a clear UVA1 molecular signature with the modulation of expression of 461 and 480 genes in epidermal keratinocytes and dermal fibroblasts, respectively (fold change> = 1.5 and adjusted p value<0.001). Functional enrichment analysis using GO, KEGG pathways and bibliographic analysis revealed a real stress with up-regulation of genes encoding heat shock proteins or involved in oxidative stress response. UVA1 also affected a wide panel of pathways and functions including cancer, proliferation, apoptosis and development, extracellular matrix and metabolism of lipids and glucose. Strikingly, one quarter of modulated genes was related to innate immunity: genes involved in inflammation were strongly up-regulated while genes involved in antiviral defense were severely down-regulated. These transcriptomic data were confirmed in dose-response and time course experiments using quantitative PCR and protein quantification. Links between the evidenced UVA1-induced impacts and clinical consequences of UVA1 exposure such as photo-aging, photo-immunosuppression and

  10. Cellular effects of UVA: DNA damages

    SciTech Connect

    Peak, M.J.; Peak, J.G.

    1988-01-01

    Ultraviolet radiation between 320 nm and visible light (UVA) is a major component of both solar radiation and suntan lamps, which are being increasingly used in tanning booths. UVA has generally been considered innocuous, partially because DNA does not absorb appreciably in this region, but UVB radiation (290-320 nm) has widely been considered to be the major etiological factor in human skin carcinogenesis caused by solar uv radiation, largely because DNA absorbs photons of UVB, which is known to produce thymine photoproducts (cyclobutane dimers and adducts). It is true that patients with xeroderma pigmentosum are particularly prone to solar-uv-induced skin cancer, and cells derived from these people have been shown to lack ability to repair pyrimidine photoproducts by excision, evidence that pyrimidine photoproducts might play a role in carcinogenesis in certain specialized situations. Normal cells have the ability to repair these UVB-induced lesions. However, UVA is considerably more penetrating and more abundant than UVB, and others have performed a spectral analysis that claimed that 20-60% (depending upon the solar zenith angle) of the toxic biological effects of solar radiation can be attributed to UVA. The fact that UVA radiations are mutagenic provides motivation for studying DNA changes that might be effected by this region of the electromagnetic spectrum.

  11. UVA, pheomelanin and the carcinogenesis of melanoma.

    PubMed

    Hill, H Z; Hill, G J

    2000-01-01

    Cloudman S91 mouse melanoma cells vary in constitutive and inducible melanin levels. Survival, mutation induction and DNA damage were quantitated after exposure to UVB, UVA and FS20 lamps. Assuming that the observed differences are related to melanin, induced pigment is photo-protective for survival and mutation after UVB and FS20 exposure, and is photosensitizing for survival after UVA exposure. No changes in pyrimidine dimers could be measured. DNA damage in pigmented mouse melanocytes (melan-a and melan-b) was greater than that in albino melanocytes (melan-c) after UVB and FS20, and the pigmented cells were more sensitive to killing. Pigment appears to be protective for killing by UVA in these melanocytes. Human melanocytes from different skin types vary in both melanin amount and composition (eu- and pheomelanin). Effects of pigmentation on UVB responses are unclear. In UVA, heavily pigmented cells have more DNA damage than lightly pigmented cells, but are resistant to killing. Increased pheomelanin photosensitizes DNA damage in lightly pigmented cells. Since eumelanin predominates in the mouse melanoma cells and melanocytes, they are less likely than human cells to provide a satisfactory model for human solar melanomagenesis. In order to understand the mechanism of photocarcinogenesis of melanoma, melanins in human melanocytes from different pigment types should be carefully quantitated and characterized. Mutations induced in them by solar wavelength-emitting lamps with well-characterized spectra should be measured, and mutant DNA should be sequenced to determine the nature of the solar-induced lesions. Research should focus on UVA and pheomelanin.

  12. Base pairing enhances fluorescence and favors cyclobutane dimer formation induced upon absorption of UVA radiation by DNA.

    PubMed

    Banyasz, Akos; Vayá, Ignacio; Changenet-Barret, Pascale; Gustavsson, Thomas; Douki, Thierry; Markovitsi, Dimitra

    2011-04-13

    The photochemical properties of the DNA duplex (dA)(20)·(dT)(20) are compared with those of the parent single strands. It is shown that base pairing increases the probability of absorbing UVA photons, probably due to the formation of charge-transfer states. UVA excitation induces fluorescence peaking at ∼420 nm and decaying on the nanosecond time scale. The fluorescence quantum yield, the fluorescence lifetime, and the quantum yield for cyclobutane dimer formation increase upon base pairing. Such behavior contrasts with that of the UVC-induced processes.

  13. UVA system for human cornea irradiation

    NASA Astrophysics Data System (ADS)

    Pereira, Fernando R. A.; Stefani, Mario; Otoboni, José A.; Richter, Eduardo H.; Rossi, Giuliano; Mota, Alessandro D.; Ventura, Liliane

    2009-02-01

    According to recent studies, an increase in corneal stiffness is a promising alternative for avoiding ectasias and for stagnating keratoconus of grades 1 and 2. The clinical treatment consists essentially of instilling Riboflavin (vitamin B2), in the cornea and then irradiating the corneal tissue, with UVA (365nm) radiation at 3mW/cm2 for 30min. This procedure provides collagen cross-linking in the corneal surface, increasing its stiffness. This work presents a system for UVA irradiation of the corneas at a peak wavelength of 365nm with adjustable power up to 5mW. The system has closed loop electronics to control the emitted power with 20% precision from the sated power output. The system is a prototype for performing corneal cross-linking and has been clinically tested. The closed loop electronics is a differential from the equipments available on the market.

  14. The COLIPA in vitro UVA method: a standard and reproducible measure of sunscreen UVA protection.

    PubMed

    Matts, P J; Alard, V; Brown, M W; Ferrero, L; Gers-Barlag, H; Issachar, N; Moyal, D; Wolber, R

    2010-02-01

    There is a continuing need to measure and communicate reliably the UVA protection offered by commercial sunscreens. To that end, the COLIPA (European Cosmetics Trade Association) 'In Vitro Sun Protection Methods' group has developed a new in vitro method for measuring UVA protection in a standardized, reproducible manner. The method is based on in vitro UV substrate spectrophotometry and convolution of resulting absorbance data with the action spectrum for the in vivo Persistent Pigment Darkening (PPD) endpoint to provide an in vitro UVA protection factor (UVAPF) which is correlated with an in vivo measure. This method has been published as a COLIPA guideline, used currently in European geographies for testing and labelling sunscreen products. This article summarizes two 'ring' studies, involving eight separate testing laboratories, which both defined critical parameters for the method and validated it. In Ring Study 1, eight laboratories tested the in vitro UV transmission of a total of 24 sunscreens and, from the data, a unit dose of UVA (D(0) of 1.2 J cm(-2)) was defined to provide a single irradiation step which, by taking into account potential sunscreen photo-instability, gave the closest agreement with in vivo UVAPF values. In Ring Study 2, eight laboratories tested the in vitro UV transmission of a total of 13 sunscreens using this single irradiation step and established a very good correlation (r(2) = 0.83; slope = 0.84, P < 0.0001) between resulting in vitro UVAPF values and corresponding values derived from the in vivo PPD method. This new method, therefore, can be used to provide a reliable in vitro metric to describe and label UVA efficacy in sunscreen products, in line with the EU Commission recommendation 2006/247/EC.

  15. New insights in photoaging, UVA induced damage and skin types.

    PubMed

    Battie, Claire; Jitsukawa, Setsuko; Bernerd, Françoise; Del Bino, Sandra; Marionnet, Claire; Verschoore, Michèle

    2014-10-01

    UVA radiation is the most prevalent component of solar UV radiation; it deeply penetrates into the skin and induces profound alterations of the dermal connective tissue. In recent years, the detrimental effects of UVA radiation were more precisely demonstrated at cellular and molecular levels, using adequate methods to identify biological targets of UVA radiation and the resulting cascade impairment of cell functions and tissue degradation. In particular gene expression studies recently revealed that UVA radiation induces modulation of several genes confirming the high sensitivity of dermal fibroblasts to UVA radiation. The major visible damaging effects of UVA radiation only appear after years of exposure: it has been clearly evidenced that they are responsible for more or less early signs of photoageing and photocarcinogenesis. UVA radiation appears to play a key role in pigmented changes occurring with age, the major sign of skin photoaging in Asians. Skin susceptibility to photoaging alterations also depends on constitutive pigmentation. The skin sensitivity to UV light has been demonstrated to be linked to skin color type.

  16. Microvascular leakage of plasma proteins after PUVA and UVA

    SciTech Connect

    Staberg, B.; Worm, A.M.; Rossing, N.; Brodthagen, H.

    1982-04-01

    The transcapillary escape rate of albumin (TERalb), is a parameter of the leakage of macromolecules from the total microvasculature. In patients with psoriasis short-term PUVA treatment induces an increase in TERalb. In this study TERalb was measured in 3 groups of normal humans treated with PUVA, UVA and 8-methoxypsoralen. Treatment with PUVA and UVA caused a statistically significant increase in TERalb, whereas treatment with 8-methoxypsoralen did not induce any measurable changes. It is concluded that the UVA irradiation causes the abnormal leakage of macromolecules, whereas psoralen is not the responsible component. Furthermore the phenomenon can be elicited in normals and is not based on a preexisting psoriasis.

  17. Examination of solar simulators used for the determination of sunscreen UVA efficacy.

    PubMed

    Sayre, Robert M; Dowdy, John C

    2010-01-01

    The U.S. FDA recently proposed both in vivo and in vitro UVA efficacy tests for sunscreen products with the lower result used to establish the sunscreen's labeled UVA protection claim. The FDA stated their rationale for dual tests was concern that the in vivo test method overemphasizes UVA-2 (320-340 nm) photoprotection. We attribute FDA's observation to the relative lack, compared to sunlight, of UVA-1 (340-400 nm) radiation in the current JCIA UVA solar simulator specification, allowing the method to generate higher UVA protection factors than sunscreens will provide in sunlight. Our work is based upon comparisons of Air Mass 1.0 sunlight to variously filtered UVA solar simulators. Sources near the JCIA UVA-2/UVA limits (8-20%) had a goodness of fit to solar UVA of only 67-79%. We propose that instead of using ratios of UVA-2 to UVA the standard should be a goodness of fit to the UVA region of an Air Mass 1 solar reference spectrum. As the spectral distribution of solar UVA varies much less than UVB, sunlight of reasonable zenith angles of < or = 60 degrees will have similar spectral shapes and approximate risk spectrum. Goodness of fit to this spectrum will produce UVA protection values predictive to those actually achieved in sunlight of different zenith angles.

  18. UVA Light-mediated Ascorbate Oxidation in Human Lenses.

    PubMed

    Rakete, Stefan; Nagaraj, Ram H

    2017-01-13

    Whether ascorbate oxidation is promoted by UVA light in human lenses and whether this process is influenced by age and GSH levels are not known. In this study, we used paired lenses from human donors. One lens of each pair was exposed to UVA light, whereas the other lens was kept in the dark for the same period of time as the control. Using LC-MS/MS analyses, we found that older lenses (41-73 years) were more susceptible to UVA-induced ascorbate oxidation than younger lenses (18-40 years). Approximately 36% of the ascorbate (relative to control) was oxidized in older lenses compared to ~16% in younger lenses. Furthermore, lenses with higher levels of GSH were less susceptible to UVA-induced ascorbate oxidation compared to those with lower levels, and this effect was not dependent on age. The oxidation of ascorbate led to elevated levels of reactive α-dicarbonyl compounds. In summary, our study showed that UVA light exposure leads to ascorbate oxidation in human lenses and that such oxidation is more pronounced in aged lenses and is inversely related to GSH levels. Our findings suggest that UVA light exposure could lead to protein aggregation through ascorbate oxidation in human lenses.

  19. Effect of UVA-activated riboflavin on dentin bonding.

    PubMed

    Cova, A; Breschi, L; Nato, F; Ruggeri, A; Carrilho, M; Tjäderhane, L; Prati, C; Di Lenarda, R; Tay, F R; Pashley, D H; Mazzoni, A

    2011-12-01

    Recent studies have reported collagen cross-linking after exposure to riboflavin followed by ultraviolet-A (UVA) exposure. This study is the first to investigate the effect of a riboflavin-containing primer on adhesive interface stability and dentinal matrix metalloproteinase activity. Human dentin was etched with 35% phosphoric acid, treated with 0.1% riboflavin, exposed to UVA for 2 min, and bonded with a two-step etch-and-rinse adhesive. Adhesive was applied to control specimens without riboflavin/UVA. Specimens were subjected to microtensile bond strength tests and pulled to failure after storage for 24 hrs, 6 mos, or 1 yr. Interfacial nanoleakage was evaluated by light and transmission electron microscopy. To investigate dentinal matrix metalloproteinase activity, we performed correlative zymographic assays on protein extracts obtained from phosphoric-acid-etched dentin powder with or without riboflavin/UVA treatment and XP Bond. Ultraviolet-activated riboflavin treatment increased the immediate bond strength to dentin at all aging intervals (p < 0.05 vs. control) and decreased interfacial nanoleakage in aged specimens (1 yr; p < 0.05). Zymograms revealed that riboflavin/UVA pre-treatment inhibited dentinal matrix metalloproteinase activity (especially MMP-9). In conclusion, dentinal collagen cross-linking induced by riboflavin/UVA increased immediate bond strength, stabilized the adhesive interface, and inhibited dentin matrix metalloproteinases, thereby increasing the durability of resin-dentin bonds.

  20. Effect of UVA-activated Riboflavin on Dentin Bonding

    PubMed Central

    Cova, A.; Breschi, L.; Nato, F.; Ruggeri, A.; Carrilho, M.; Tjäderhane, L.; Prati, C.; Di Lenarda, R.; Tay, F.R.; Pashley, D.H.; Mazzoni, A.

    2011-01-01

    Recent studies have reported collagen cross-linking after exposure to riboflavin followed by ultraviolet-A (UVA) exposure. This study is the first to investigate the effect of a riboflavin-containing primer on adhesive interface stability and dentinal matrix metalloproteinase activity. Human dentin was etched with 35% phosphoric acid, treated with 0.1% riboflavin, exposed to UVA for 2 min, and bonded with a two-step etch-and-rinse adhesive. Adhesive was applied to control specimens without riboflavin/UVA. Specimens were subjected to microtensile bond strength tests and pulled to failure after storage for 24 hrs, 6 mos, or 1 yr. Interfacial nanoleakage was evaluated by light and transmission electron microscopy. To investigate dentinal matrix metalloproteinase activity, we performed correlative zymographic assays on protein extracts obtained from phosphoric-acid-etched dentin powder with or without riboflavin/UVA treatment and XP Bond. Ultraviolet-activated riboflavin treatment increased the immediate bond strength to dentin at all aging intervals (p < 0.05 vs. control) and decreased interfacial nanoleakage in aged specimens (1 yr; p < 0.05). Zymograms revealed that riboflavin/UVA pre-treatment inhibited dentinal matrix metalloproteinase activity (especially MMP-9). In conclusion, dentinal collagen cross-linking induced by riboflavin/UVA increased immediate bond strength, stabilized the adhesive interface, and inhibited dentin matrix metalloproteinases, thereby increasing the durability of resin-dentin bonds. PMID:21940521

  1. DNA repair inhibition by UVA photoactivated fluoroquinolones and vemurafenib

    PubMed Central

    Peacock, Matthew; Brem, Reto; Macpherson, Peter; Karran, Peter

    2014-01-01

    Cutaneous photosensitization is a common side effect of drug treatment and can be associated with an increased skin cancer risk. The immunosuppressant azathioprine, the fluoroquinolone antibiotics and vemurafenib—a BRAF inhibitor used to treat metastatic melanoma—are all recognized clinical photosensitizers. We have compared the effects of UVA radiation on cultured human cells treated with 6-thioguanine (6-TG, a DNA-embedded azathioprine surrogate), the fluoroquinolones ciprofloxacin and ofloxacin and vemurafenib. Despite widely different structures and modes of action, each of these drugs potentiated UVA cytotoxicity. UVA photoactivation of 6-TG, ciprofloxacin and ofloxacin was associated with the generation of singlet oxygen that caused extensive protein oxidation. In particular, these treatments were associated with damage to DNA repair proteins that reduced the efficiency of nucleotide excision repair. Although vemurafenib was also highly phototoxic to cultured cells, its effects were less dependent on singlet oxygen. Highly toxic combinations of vemurafenib and UVA caused little protein carbonylation but were nevertheless inhibitory to nucleotide excision repair. Thus, for three different classes of drugs, photosensitization by at least two distinct mechanisms is associated with reduced protection against potentially mutagenic and carcinogenic DNA damage. PMID:25414333

  2. UVA phototransduction drives early melanin synthesis in human melanocytes.

    PubMed

    Wicks, Nadine L; Chan, Jason W; Najera, Julia A; Ciriello, Jonathan M; Oancea, Elena

    2011-11-22

    Exposure of human skin to solar ultraviolet radiation (UVR), a powerful carcinogen [1] comprising ~95% ultraviolet A (UVA) and ~5% ultraviolet B (UVB) at the Earth's surface, promotes melanin synthesis in epidermal melanocytes [2, 3], which protects skin from DNA damage [4, 5]. UVB causes DNA lesions [6] that lead to transcriptional activation of melanin-producing enzymes, resulting in delayed skin pigmentation within days [7]. In contrast, UVA causes primarily oxidative damage [8] and leads to immediate pigment darkening (IPD) within minutes, via an unknown mechanism [9, 10]. No receptor protein directly mediating phototransduction in skin has been identified. Here we demonstrate that exposure of primary human epidermal melanocytes (HEMs) to UVA causes calcium mobilization and early melanin synthesis. Calcium responses were abolished by treatment with G protein or phospholipase C (PLC) inhibitors or by depletion of intracellular calcium stores. We show that the visual photopigment rhodopsin [11] is expressed in HEMs and contributes to UVR phototransduction. Upon UVR exposure, significant melanin production was measured within one hour; cellular melanin continued to increase in a retinal- and calcium-dependent manner up to 5-fold after 24 hr. Our findings identify a novel UVA-sensitive signaling pathway in melanocytes that leads to calcium mobilization and melanin synthesis and may underlie the mechanism of IPD in human skin.

  3. Proteomic identification of cathepsin B and nucleophosmin as novel UVA-targets in human skin fibroblasts.

    PubMed

    Lamore, Sarah D; Qiao, Shuxi; Horn, David; Wondrak, Georg T

    2010-01-01

    Solar UVA exposure plays a causative role in skin photoaging and photocarcinogenesis. Here, we describe the proteomic identification of novel UVA-targets in human dermal fibroblasts following a two-dimensional-difference-gel-electrophoresis (2D-DIGE) approach. Fibroblasts were exposed to noncytotoxic doses of UVA or left untreated, and total protein extracts underwent CyDye-labeling followed by 2D-DIGE/mass-spectrometric identification of differentially expressed proteins, confirmed independently by immunodetection. The protein displaying the most pronounced UVA-induced upregulation was identified as the nucleolar protein nucleophosmin. The protein undergoing the most pronounced UVA-induced downregulation was identified as cathepsin B, a lysosomal cysteine-protease displaying loss of enzymatic activity and altered maturation after cellular UVA exposure. Extensive lysosomal accumulation of lipofuscin-like autofluorescence and osmiophilic material occurred in UVA-exposed fibroblasts as detected by confocal fluorescence microscopy and transmission electron microscopy, respectively. Array analysis indicated UVA-induced upregulation of oxidative stress response gene expression, and UVA-induced loss of cathepsin B enzymatic activity in fibroblasts was suppressed by antioxidant intervention. Pharmacological cathepsin B inhibition using CA074Me mimicked UVA-induced accumulation of lysosomal autofluorescence and deficient cathepsin B maturation. Taken together, these data support the hypothesis that cathepsin B is a crucial target of UVA-induced photo-oxidative stress causatively involved in dermal photodamage through the impairment of lysosomal removal of lipofuscin.

  4. Quantification of Thiopurine/UVA-Induced Singlet Oxygen Production

    PubMed Central

    Zhang, Yazhou; Barnes, Ashley N.; Zhu, Xianchun; Campbell, Naomi F.; Gao, Ruomei

    2011-01-01

    Thiopurines were examined for their ability to produce singlet oxygen (1O2) with UVA light. The target compounds were three thiopurine prodrugs, azathioprine (Aza), 6-mercaptopurine (6-MP) and 6-thioguanine (6-TG), and their S-methylated derivatives of 6-methylmercaptopurine (me6-MP) and 6-methylthioguanine (me6-TG). Our results showed that these thiopurines were efficient 1O2 sensitizers under UVA irradiation but rapidly lost their photoactivities for 1O2 production over time by a self-sensitized photooxidation of sulfur atoms in the presence of oxygen and UVA light. The initial quantum yields of 1O2 production were determined to be in the range of 0.30–0.6 in aqueous solutions. Substitution of a hydrogen atom with a nitroimidazole or methyl group at S decreased the efficacy of photosensitized 1O2 production as found for Aza, me6-MP and me6-TG. 1O2-induced formation of 8-oxo-7,8-dihydro-2’-dexyguanosine (8-oxodGuo) was assessed by incubation of 6-methylthiopurine/UVA-treated calf thymus DNA with human repair enzyme 8-oxodGuo DNA glycosylase (hOGG1), followed by apurinic (AP) site determination. Because more 8-oxodGuo was formed in Tris D2O than in Tris H2O, 1O2 is implicated as a key species in the reaction. These findings provided quantitative information on the photosensitization efficacy of thiopurines and to some extent revealed the correlations between photoactivity and phototoxicity. PMID:22081749

  5. NASA-UVa light aerospace alloy and structures technology program

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.; Haviland, John K.; Herakovich, Carl T.; Pilkey, Walter D.; Pindera, Marek-Jerzy; Scully, John R.; Stoner, Glenn E.; Swanson, Robert E.; Thornton, Earl A.; Wawner, Franklin E., Jr.

    1991-01-01

    The general objective of the NASA-UVa Light Aerospace Alloy and Structures Technology Program was to conduct research on the performance of next generation, light weight aerospace alloys, composites, and associated thermal gradient structures. The following research areas were actively investigated: (1) mechanical and environmental degradation mechanisms in advanced light metals and composites; (2) aerospace materials science; (3) mechanics of materials and composites for aerospace structures; and (4) thermal gradient structures.

  6. Homogeneous UVA system for corneal cross-linking treatment

    NASA Astrophysics Data System (ADS)

    Ayres Pereira, Fernando R.; Stefani, Mario A.; Otoboni, José A.; Richter, Eduardo H.; Ventura, Liliane

    2010-02-01

    The treatment of keratoconus and corneal ulcers by collagen cross-linking using ultraviolet type A irradiation, combined with photo-sensitizer Riboflavin (vitamin B2), is a promising technique. The standard protocol suggests instilling Riboflavin in the pre-scratched cornea every 5min for 30min, during the UVA irradiation of the cornea at 3mW/cm2 for 30 min. This process leads to an increase of the biomechanical strength of the cornea, stopping the progression, or sometimes, even reversing Keratoconus. The collagen cross-linking can be achieved by many methods, but the utilization of UVA light, for this purpose, is ideal because of its possibility of a homogeneous treatment leading to an equal result along the treated area. We have developed a system, to be clinically used for treatment of unhealthy corneas using the cross-linking technique, which consists of an UVA emitting delivery device controlled by a closed loop system with high homogeneity. The system is tunable and delivers 3-5 mW/cm2, at 365nm, for three spots (6mm, 8mm and 10mm in diameter). The electronics close loop presents 1% of precision, leading to an overall error, after the calibration, of less than 10% and approximately 96% of homogeneity.

  7. UVA experimental and high energy physics. Final grant report

    SciTech Connect

    Cox, B.

    1999-10-07

    The period 1992--1997 was a mixture of frustrations and of accomplishments for the UVa HEP group. The experimental HEP group began this period with the completion of a truncated run of Experiment E771 at Fermilab in 1992. This experiment was designed to measure the cross section for beauty production in 800 GeV/c pN interactions. It succeeded in this goal as well as in obtaining one of the best limits on FCNC in charm decays by setting an upper limit on D{sup 0} {r_arrow} {mu}{sup +}{mu}{sup {minus}}. In addition, they were able to measure {Psi}, {Psi}, {chi}{sub 1},{chi}{sub 2} and upsilon production. Three UVa PhD theses have resulted from this experiment (as well as 12 other PhD's at other institutions). At the same time, the UVa experimental group was vigorously pursuing the goal of studying CP violation in B production. This took the form of a proposal to the SSC for a super fixed target facility, the SFT, which would focus on studies of B mesons. B. Cox was the spokesman of this experiment that had over thirty institutions. This proposal EOI-14 had a good reception by the SSC PAC. A R and D activity to prove the technique of crystal channeling was undertaken to prove the accelerator aspects of this proposal. This activity, known as E853 or CEX at Fermilab, resulted in proof of the crystal channeling technique as viable for the extraction of 20 TeV beam at the SSC. In addition to this activity, the UVa group investigated many other aspects of B physics at the SSC. They were among the leaders of the 1993 Snowmass meeting on B Physics at Hadronic Accelerators. The UVa HEP group worked vigorously on developing the ideas for B physics at the SSC, as evidenced by the many different studies listed in the publication list given, up to the very day the SSC was terminated by an act of Congress.

  8. Ultraviolet-A (UVA-1) radiation suppresses immunoglobulin production of activated B lymphocytes in vitro.

    PubMed

    Polderman, M C A; van Kooten, C; Smit, N P M; Kamerling, S W A; Pavel, S

    2006-09-01

    Previous studies have shown that low-dose ultraviolet-A (UVA-1) total body irradiations were capable of improving disease activity in patients with systemic lupus erythematosus (SLE). We hypothesized that UVA-1-induced suppression of immunoglobulin production by activated B cells in the dermal capillaries could be (partly) responsible for this effect. Our experiments with donor skin demonstrated that approximately 40% of UVA-1 could penetrate through the epidermis. Irradiation of peripheral blood mononuclear cells (PBMCs) with 2 J/cm(2) of UVA-1 resulted in 20% cell death. This toxic effect could be prevented totally by preincubation of the cell cultures with catalase. This indicates that the generation of hydrogen peroxide plays a role in UVA-1 cytotoxicity. T cells and B cells appeared to be less susceptible to UVA-1 cytotoxicity than monocytes. With the use of a CD40-CD40L B cell activation method we measured immunoglobulin production after various doses of UVA-1 irradiation (0-2 J/cm(2)). The doses of 2 J/cm(2) caused a significant decrease of IgM, IgG, IgA and IgE production under the conditions of interleukin (IL)-10 or IL-4 (IgE) stimulation. Although UVA-1 can cause apoptosis of B lymphocytes, we show that relatively low doses of UVA-1 radiation also affect the function of these cells. Both effects may be responsible for the observed improvement of disease activity in SLE patients.

  9. Effect of UVA fluence rate on indicators of oxidative stress in human dermal fibroblasts.

    PubMed

    Hoerter, James D; Ward, Christopher S; Bale, Kyle D; Gizachew, Admasu N; Graham, Rachelle; Reynolds, Jaclyn; Ward, Melanie E; Choi, Chesca; Kagabo, Jean-Leonard; Sauer, Michael; Kuipers, Tara; Hotchkiss, Timothy; Banner, Nate; Chellson, Renee A; Ohaeri, Theresa; Gant, Langston; Vanderhill, Leah

    2008-02-19

    During the course of a day human skin is exposed to solar UV radiation that fluctuates in fluence rate within the UVA (290-315 nm) and UVB (315-400 nm) spectrum. Variables affecting the fluence rate reaching skin cells include differences in UVA and UVB penetrating ability, presence or absence of sunscreens, atmospheric conditions, and season and geographical location where the exposure occurs. Our study determined the effect of UVA fluence rate in solar-simulated (SSR) and tanning-bed radiation (TBR) on four indicators of oxidative stress---protein oxidation, glutathione, heme oxygenase-1, and reactive oxygen species--in human dermal fibroblasts after receiving equivalent UVA and UVB doses. Our results show that the higher UVA fluence rate in TBR increases the level of all four indicators of oxidative stress. In sequential exposures when cells are exposed first to SSR, the lower UVA fluence rate in SSR induces a protective response that protects against oxidative stress following a second exposure to a higher UVA fluence rate. Our studies underscore the important role of UVA fluence rate in determining how human skin cells respond to a given dose of radiation containing both UVA and UVB radiation.

  10. Ectoin: an effective natural substance to prevent UVA-induced premature photoaging.

    PubMed

    Buenger, J; Driller, H

    2004-01-01

    With the help of a new 'UVA stress model', it was shown that Ectoin protects the skin from the effects of UVA-induced cell damage in a number of different ways. Using cell cultures, high-performance thin-layer chromatography, gel electrophoresis mobility shift assays, reverse transcriptase polymerase chain reaction, ion exchange chromatography and UV spectroscopy, it was demonstrated that the UVA-induced second messenger release, transcription factor AP-2 activation, intercellular adhesion molecule-1 expression and mitochondrial DNA mutation could be prevented. The results obtained clearly demonstrate that Ectoin counteracts the effects of UVA-induced and accelerated skin aging at different cell levels.

  11. Photoprotection by dietary phenolics against melanogenesis induced by UVA through Nrf2-dependent antioxidant responses.

    PubMed

    Chaiprasongsuk, Anyamanee; Onkoksoong, Tasanee; Pluemsamran, Thanyawan; Limsaengurai, Saowalak; Panich, Uraiwan

    2016-08-01

    Dietary phenolics may play a protective role in UV-mediated skin pigmentation through their antioxidant and UV-absorbing actions. In this study, we investigated whether genetic silencing of Nrf2, regulating the transcription of antioxidant genes, affected melanogenesis in primary human epidermal melanocytes (HEMn) and B16F10 melanoma cells subjected to UVA (8J/cm(2)) exposure. Then, we explored the antimelanogenic actions of phenolics; caffeic acid (CA) and ferulic acid (FA) providing partial UVA protection; quercetin (QU) and rutin (RU) providing strong UVA protection and; avobenzone (AV), an efficient UVA filter, in association with modulation of Nrf2-mediated antioxidant defenses in response to UVA insults in B16F10 cells. Upon oxidative insults, Nrf2 silencing promoted melanogenesis in both HEMn and B16F10 cells irradiated with UVA. Stimulation of melanogenesis by UVA correlated with increased ROS and oxidative DNA damage (8-OHdG), GSH depletion as well as a transient downregulation of Nrf2 nuclear translocation and of Nrf2-ARE signaling in B16F10 cells. All test compounds exerted antimelanogenic effects with respect to their abilities to reverse UVA-mediated oxidative damage as well as downregulation of Nrf2 activity and its target antioxidants (GCLC, GST and NQO1) in B16F10 cells. In conclusion, defective Nrf2 may promote melanogenesis under UVA irradiation through oxidative stress mechanisms. Compounds with antioxidant and/or UVA absorption properties could protect against UVA-induced melanogenesis through indirect regulatory effect on Nrf2-ARE pathway.

  12. Photoprotection by dietary phenolics against melanogenesis induced by UVA through Nrf2-dependent antioxidant responses

    PubMed Central

    Chaiprasongsuk, Anyamanee; Onkoksoong, Tasanee; Pluemsamran, Thanyawan; Limsaengurai, Saowalak; Panich, Uraiwan

    2015-01-01

    Dietary phenolics may play a protective role in UV-mediated skin pigmentation through their antioxidant and UV-absorbing actions. In this study, we investigated whether genetic silencing of Nrf2, regulating the transcription of antioxidant genes, affected melanogenesis in primary human epidermal melanocytes (HEMn) and B16F10 melanoma cells subjected to UVA (8 J/cm2) exposure. Then, we explored the antimelanogenic actions of phenolics; caffeic acid (CA) and ferulic acid (FA) providing partial UVA protection; quercetin (QU) and rutin (RU) providing strong UVA protection and; avobenzone (AV), an efficient UVA filter, in association with modulation of Nrf2-mediated antioxidant defenses in response to UVA insults in B16F10 cells. Upon oxidative insults, Nrf2 silencing promoted melanogenesis in both HEMn and B16F10 cells irradiated with UVA. Stimulation of melanogenesis by UVA correlated with increased ROS and oxidative DNA damage (8-OHdG), GSH depletion as well as a transient downregulation of Nrf2 nuclear translocation and of Nrf2-ARE signaling in B16F10 cells. All test compounds exerted antimelanogenic effects with respect to their abilities to reverse UVA-mediated oxidative damage as well as downregulation of Nrf2 activity and its target antioxidants (GCLC, GST and NQO1) in B16F10 cells. In conclusion, defective Nrf2 may promote melanogenesis under UVA irradiation through oxidative stress mechanisms. Compounds with antioxidant and/or UVA absorption properties could protect against UVA-induced melanogenesis through indirect regulatory effect on Nrf2-ARE pathway. PMID:26765101

  13. UVA Causes Dual Inactivation of Cathepsin B and L Underlying Lysosomal Dysfunction in Human Dermal Fibroblasts

    PubMed Central

    Lamore, Sarah D.; Wondrak, Georg T.

    2013-01-01

    Cutaneous exposure to chronic solar UVA-radiation is a causative factor in photocarcinogenesis and photoaging. Recently, we have identified the thiol-dependent cysteine-protease cathepsin B as a novel UVA-target undergoing photo-oxidative inactivation upstream of autophagic-lysosomal dysfunction in fibroblasts. In this study, we examined UVA effects on a wider range of cathepsins and explored the occurrence of UVA-induced cathepsin inactivation in other cultured skin cell types. In dermal fibroblasts, chronic exposure to non-cytotoxic doses of UVA caused pronounced inactivation of the lysosomal cysteine-proteases cathepsin B and L, effects not observed in primary keratinocytes and occurring only to a minor extent in primary melanocytes. In order to determine if UVA-induced lysosomal impairment requires single or dual inactivation of cathepsin B and/or L, we used a genetic approach (siRNA) to selectively downregulate enzymatic activity of these target cathepsins. Monitoring an established set of protein markers (including LAMP1, LC3-II, and p62) and cell ultrastructural changes detected by electron microscopy, we observed that only dual genetic antagonism (targeting both CTSB and CTSL expression) could mimic UVA-induced autophagic-lysosomal alterations, whereas single knockdown (targeting CTSB or CTSL only) did not display ‘UVA-mimetic’ effects failing to reproduce the UVA-induced phenotype. Taken together, our data demonstrate that chronic UVA inhibits both cathepsin B and L enzymatic activity and that dual inactivation of both enzymes is a causative factor underlying UVA-induced impairment of lysosomal function in dermal fibroblasts. PMID:23603447

  14. UVA causes dual inactivation of cathepsin B and L underlying lysosomal dysfunction in human dermal fibroblasts.

    PubMed

    Lamore, Sarah D; Wondrak, Georg T

    2013-06-05

    Cutaneous exposure to chronic solar UVA-radiation is a causative factor in photocarcinogenesis and photoaging. Recently, we have identified the thiol-dependent cysteine-protease cathepsin B as a novel UVA-target undergoing photo-oxidative inactivation upstream of autophagic-lysosomal dysfunction in fibroblasts. In this study, we examined UVA effects on a wider range of cathepsins and explored the occurrence of UVA-induced cathepsin inactivation in other cultured skin cell types. In dermal fibroblasts, chronic exposure to non-cytotoxic doses of UVA caused pronounced inactivation of the lysosomal cysteine-proteases cathepsin B and L, effects not observed in primary keratinocytes and occurring only to a minor extent in primary melanocytes. In order to determine if UVA-induced lysosomal impairment requires single or dual inactivation of cathepsin B and/or L, we used a genetic approach (siRNA) to selectively downregulate enzymatic activity of these target cathepsins. Monitoring an established set of protein markers (including LAMP1, LC3-II, and p62) and cell ultrastructural changes detected by electron microscopy, we observed that only dual genetic antagonism (targeting both CTSB and CTSL expression) could mimic UVA-induced autophagic-lysosomal alterations, whereas single knockdown (targeting CTSB or CTSL only) did not display 'UVA-mimetic' effects failing to reproduce the UVA-induced phenotype. Taken together, our data demonstrate that chronic UVA inhibits both cathepsin B and L enzymatic activity and that dual inactivation of both enzymes is a causative factor underlying UVA-induced impairment of lysosomal function in dermal fibroblasts.

  15. UVB and UVA irradiances from indoor tanning devices.

    PubMed

    Nilsen, Lill Tove N; Aalerud, Tommy Nakken; Hannevik, Merete; Veierød, Marit B

    2011-07-01

    Indoor tanning is common in spite of its classification as carcinogenic. Too high an ultraviolet (UV) irradiance and a lack of compliance with regulations have been reported. We measured UV irradiance from a large number of Norwegian solariums (sunbeds and stand-up cabinets) currently in use. Compliance (solariums and facilities) with national regulations and the effect of inspections delegated to local authorities (since 2004) were also studied. In 2008, 78 tanning facilities were selected from six regions throughout Norway that contained municipalities with and without local inspections. UV irradiance was measured with a CCD spectroradiometer in 194 out of 410 inspected solariums. Mean erythema weighted short (280-320 nm) and long (320-400 nm) wave UV irradiances were 0.194 (95% confidence interval (CI) 0.184-0.205) and 0.156 (95% CI 0.148-0.164) W m(-2), respectively. Only 23% of the solariums were below the UV type 3 limit (<0.15 W m(-2), short and long wave). Irradiances varied between solariums: spectral UVB (280-315 nm) and UVA (315-400 nm) irradiances were 0.5-3.7 and 3-26 times, respectively, higher than from Oslo summer sun. In total, 89.9% of the tanning facilities were unattended. Overall compliance increased since the first study in 1998-1999, but total UV irradiance did not decrease, mainly because of higher UVA irradiance in 2008. Solariums have become even less similar to natural sun due to higher UVA irradiance. Local inspections gave better compliance with regulations, but irradiances were significantly higher in municipalities with inspections (p ≤ 0.001, compared to without). Unpredictable UV irradiance combined with insufficient customer guidance may give a high risk of negative health effects from solarium use.

  16. Functional changes induced by chronic UVA irradiation to cultured human dermal fibroblasts.

    PubMed

    Naru, E; Suzuki, T; Moriyama, M; Inomata, K; Hayashi, A; Arakane, K; Kaji, K

    2005-12-01

    Ultraviolet (UV) irradiation induces damage of the skin, and in particular, photoageing is known to be the result of chronic UV irradiation. Many investigations have attempted to clarify the mechanisms of photoageing induced by chronic UVA irradiation, but consensus has not been achieved yet by in vivo experiments, mostly due to differences among UV sources and animals used for experiments. In vitro experiments have shown that a single exposure to UVA irradiation causes overexpression of matrix metalloproteinases and denaturation of collagen, but the mechanisms of the photoageing effects of chronic UVA irradiation are still unclear. To examine the effects of chronic UVA irradiation, we used an in vitro fibroblast cellular ageing system as a model of photoageing. Chronic UVA irradiation of normal human fibroblasts induced shortening of the cellular life span and an increase of cellular diameter, in parallel with expression of senescence-associated beta-galactosidase. Extracellular degradation enzyme, matrix metalloproteinase 1 (MMP-1) was overexpressed after repeated UVA irradiation, but tissue inhibitor of metalloproteinase 1 (TIMP-1) expression was hardly changed by chronic UVA irradiation. We conclude that chronic UVA irradiation of normal human fibroblasts induces cellular functional changes, leading to accelerated cellular ageing and MMP-1 overexpression.

  17. Exposure of vitamins to UVB and UVA radiation generates singlet oxygen.

    PubMed

    Knak, Alena; Regensburger, Johannes; Maisch, Tim; Bäumler, Wolfgang

    2014-05-01

    Deleterious effects of UV radiation in tissue are usually attributed to different mechanisms. Absorption of UVB radiation in cell constituents like DNA causes photochemical reactions. Absorption of UVA radiation in endogenous photosensitizers like vitamins generates singlet oxygen via photosensitized reactions. We investigated two further mechanisms that might be involved in UV mediated cell tissue damage. Firstly, UVB radiation and vitamins also generate singlet oxygen. Secondly, UVB radiation may change the chemical structure of vitamins that may change the role of such endogenous photosensitizers in UVA mediated mechanisms. Vitamins were irradiated in solution using monochromatic UVB (308 nm) or UVA (330, 355, or 370 nm) radiation. Singlet oxygen was directly detected and quantified by its luminescence at 1270 nm. All investigated molecules generated singlet oxygen with a quantum yield ranging from 0.007 (vitamin D3) to 0.64 (nicotinamide) independent of the excitation wavelength. Moreover, pre-irradiation of vitamins with UVB changed their absorption in the UVB and UVA spectral range. Subsequently, molecules such as vitamin E and vitamin K1, which normally exhibit no singlet oxygen generation in the UVA, now produce singlet oxygen when exposed to UVA at 355 nm. This interplay of different UV sources is inevitable when applying serial or parallel irradiation with UVA and UVB in experiments in vitro. These results should be of particular importance for parallel irradiation with UVA and UVB in vivo, e.g. when exposing the skin to solar radiation.

  18. Essential role of Nrf2 in keratinocyte protection from UVA by quercetin

    SciTech Connect

    Kimura, Shintarou; Warabi, Eiji; Yanagawa, Toru; Ma, Dongmei; Itoh, Ken; Ishii, Yoshiyuki; Kawachi, Yasuhiro; Ishii, Tetsuro

    2009-09-11

    Much of the cell injury caused by ultraviolet A (UVA) irradiation is associated with oxidative stress. Quercetin is a major natural polyphenol that is known to protect cells from UVA-induced damage. Here, we investigated the molecular mechanism of this protection. Quercetin pretreatment strongly suppressed UVA-induced apoptosis in human keratinocyte HaCaT cells, markedly increased protein levels of the transcription factor Nrf2, induced the expression of antioxidative genes, and dramatically reduced the production of reactive oxygen species following UVA irradiation. Importantly, these beneficial effects were greatly attenuated by downregulating Nrf2 expression. Thus, quercetin protects cells from UVA damage mainly by elevating intracellular antioxidative activity via the enhanced accumulation of a transcription factor for antioxidant genes, Nrf2.

  19. Skin cell protection against UVA by Sideroxyl, a new antioxidant complementary to sunscreens.

    PubMed

    Pygmalion, Marie-Jocelyne; Ruiz, Laetitia; Popovic, Evelyne; Gizard, Julie; Portes, Pascal; Marat, Xavier; Lucet-Levannier, Karine; Muller, Benoit; Galey, Jean-Baptiste

    2010-12-01

    Oxidative stress resulting from photosensitized ROS production in skin is widely accepted as the main contributor to the deleterious effects of UVA exposure. Among the mechanisms known to be involved in UVA-induced oxidative damage, iron plays a central role. UVA radiation of skin cells induces an immediate release of iron, which can then act as a catalyst for uncontrolled oxidation reactions of cell components. Such site-specific damage can scarcely be counteracted by classical antioxidants. In contrast, iron chelators potentially offer an effective way to protect skin against UVA insults. However, iron chelation is very difficult to achieve without disturbing iron homeostasis or inducing iron depletion. A novel compound was developed to avoid these potentially harmful side effects. Sideroxyl was designed to acquire its strong chelating capability only during oxidative stress according to an original process of intramolecular hydroxylation. Herein, we describe in vitro results demonstrating the protective efficiency of Sideroxyl against deleterious effects of UVA at the molecular, cellular, and tissular levels. First, the Sideroxyl diacid form protects a model protein against UVA-induced photosensitized carbonylation. Second, intracellular ROS are dose-dependently decreased in the presence of Sideroxyl in both human cultured fibroblasts and human keratinocytes. Third, Sideroxyl protects normal human fibroblasts against UVA-induced DNA damage as measured by the comet assay and MMP-1 production. Finally, Sideroxyl provides protection against UVA-induced alterations in human reconstructed skin. These results suggest that Sideroxyl may prevent UVA-induced damage in human skin as a complement to sunscreens, especially in the long-wavelength UVA range.

  20. Prevention of UVA-Induced Oxidative Damage in Human Dermal Fibroblasts by New UV Filters, Assessed Using a Novel In Vitro Experimental System

    PubMed Central

    Emanuelli, Monica; Damiani, Elisabetta

    2014-01-01

    Background UVA rays present in sunlight are able to reach the dermal skin layer generating reactive oxygen species (ROS) responsible for oxidative damage, alterations in gene expression, DNA damage, leading to cell inflammation, photo-ageing/-carcinogenesis. Sunscreens contain UV filters as active ingredients that absorb/reflect/dissipate UV radiation: their efficiency depends on their spectral profile and photostability which should then be reflected in biological protection of underlying skin. Methods A set of new UV filters was synthesized, and the most photostable one was compared to BMDBM, a widely used UVA filter. Cultured human dermal fibroblasts were exposed to UVA radiation which was filtered by a base cream containing or not UV filters placed above cell culture wells. The endpoints measured were: cell viability (MTT assay), ROS generation (DCFH-DA assay), mitochondrial function (JC-1 assay), DNA integrity (Comet assay) and gene expression (MMP-1, COL1A1) by RT-qPCR. Results The new UV filter resulted more efficient than BMDBM in preserving cell viability, mitochondrial functionality and oxidative DNA damage, despite similar inhibition levels of intracellular ROS. Moreover, expression of genes involved in dermal photoageing were positively affected by the filtering action of the tested molecules. Conclusions The experimental model proposed was able to validate the efficacy of the new UV filter, taking into account important cellular events related to UV-induced intracellular oxidative stress, often underestimated in the assessments of these compounds. General Significance The model may be used to compare the actual biological protection of commercial sunscreens and suncare products aside from their SPF and UVA-PF values. PMID:24409282

  1. Apoptosis induction is involved in UVA-induced autolysis in sea cucumber Stichopus japonicus.

    PubMed

    Qi, Hang; Fu, Hui; Dong, Xiufang; Feng, Dingding; Li, Nan; Wen, Chengrong; Nakamura, Yoshimasa; Zhu, Beiwei

    2016-05-01

    Autolysis easily happens to sea cucumber (Stichopus japonicus, S. japonicus) for external stimulus like UV exposure causing heavy economic losses. Therefore, it is meaningful to reveal the mechanism of S. japonicas autolysis. In the present study, to examine the involvement of apoptosis induction in UVA-induced autolysis of S. japonicas, we investigated the biochemical events including the DNA fragmentation, caspase-3 activation, mitogen-activated protein kinases (MAPKs) phosphorylation and free radical formation. Substantial morphological changes such as intestine vomiting and dermatolysis were observed in S. japonicus during the incubation after 1-h UVA irradiation (10W/m(2)). The degradation of the structural proteins and enhancement of cathepsin L activity were also detected, suggesting the profound impact of proteolysis caused by the UVA irradiation even for 1h. Furthermore, the DNA fragmentation and specific activity of caspase-3 was increased up to 12h after UVA irradiation. The levels of phosphorylated p38 mitogen activated protein kinase (MAPK) and phosphorylated c-Jun.-N-terminal kinase (JNK) were significantly increased by the UVA irradiation for 1h. An electron spin resonance (ESR) analysis revealed that UVA enhanced the free radical formation in S. japonicas, even through we could not identify the attributed species. These results suggest that UVA-induced autolysis in S. japonicas at least partially involves the oxidative stress-sensitive apoptosis induction pathway. These data present a novel insight into the mechanisms of sea cucumber autolysis induced by external stress.

  2. Platelet-Rich Fibrin Lysate Can Ameliorate Dysfunction of Chronically UVA-Irradiated Human Dermal Fibroblasts.

    PubMed

    Wirohadidjojo, Yohanes Widodo; Budiyanto, Arief; Soebono, Hardyanto

    2016-09-01

    To determine whether platelet-rich fibrin lysate (PRF-L) could restore the function of chronically ultraviolet-A (UVA)-irradiated human dermal fibroblasts (HDFs), we isolated and sub-cultured HDFs from six different human foreskins. HDFs were divided into two groups: those that received chronic UVA irradiation (total dosages of 10 J cm⁻²) and those that were not irradiated. We compared the proliferation rates, collagen deposition, and migration rates between the groups and between chronically UVA-irradiated HDFs in control and PRF-L-treated media. Our experiment showed that chronic UVA irradiation significantly decreased (p<0.05) the proliferation rates, migration rates, and collagen deposition of HDFs, compared to controls. Compared to control media, chronically UVA-irradiated HDFs in 50% PRF-L had significantly increased proliferation rates, migration rates, and collagen deposition (p<0.05), and the migration rates and collagen deposition of chronically UVA-irradiated HDFs in 50% PRF-L were equal to those of normal fibroblasts. Based on this experiment, we concluded that PRF-L is a good candidate material for treating UVA-induced photoaging of skin, although the best method for its clinical application remains to be determined.

  3. Platelet-Rich Fibrin Lysate Can Ameliorate Dysfunction of Chronically UVA-Irradiated Human Dermal Fibroblasts

    PubMed Central

    Budiyanto, Arief; Soebono, Hardyanto

    2016-01-01

    To determine whether platelet-rich fibrin lysate (PRF-L) could restore the function of chronically ultraviolet-A (UVA)-irradiated human dermal fibroblasts (HDFs), we isolated and sub-cultured HDFs from six different human foreskins. HDFs were divided into two groups: those that received chronic UVA irradiation (total dosages of 10 J cm-2) and those that were not irradiated. We compared the proliferation rates, collagen deposition, and migration rates between the groups and between chronically UVA-irradiated HDFs in control and PRF-L-treated media. Our experiment showed that chronic UVA irradiation significantly decreased (p<0.05) the proliferation rates, migration rates, and collagen deposition of HDFs, compared to controls. Compared to control media, chronically UVA-irradiated HDFs in 50% PRF-L had significantly increased proliferation rates, migration rates, and collagen deposition (p<0.05), and the migration rates and collagen deposition of chronically UVA-irradiated HDFs in 50% PRF-L were equal to those of normal fibroblasts. Based on this experiment, we concluded that PRF-L is a good candidate material for treating UVA-induced photoaging of skin, although the best method for its clinical application remains to be determined. PMID:27401663

  4. Role of the Pseudomonas quinolone signal (PQS) in sensitising Pseudomonas aeruginosa to UVA radiation.

    PubMed

    Pezzoni, Magdalena; Meichtry, Martín; Pizarro, Ramón A; Costa, Cristina S

    2015-01-01

    One of the main stress factors that bacteria face in the environment is solar ultraviolet-A (UVA) radiation, which leads to lethal effects through oxidative damage. The aim of this work was to investigate the role of 2-heptyl-3-hydroxi-4-quinolone (the Pseudomonas quinolone signal or PQS) in the response of Pseudomonas aeruginosa to UVA radiation. PQS is an intercellular quorum sensing signal associated to membrane vesicles which, among other functions, regulates genes related to iron acquisition, forms stable complexes with iron and participates in oxidative phenomena. UVA exposure of the wild-type PAO1 strain and a pqsA mutant unable to produce PQS revealed a sensitising role for this signal. Research into the mechanism involved in this phenomenon revealed that catalase, an essential factor in the UVA defence, is not related to PQS-mediated UVA sensitivity. Absorption of UVA by PQS produced its own photo-degradation, oxidation of the probe 2',7'- dichlorodihydrofluorescein and generation of singlet oxygen and superoxide anion, suggesting that this signal could be acting as an endogenous photosensitiser. The results presented in this study could explain the high sensitivity to UVA of P. aeruginosa when compared to enteric bacteria.

  5. Glutathione peroxidase-1 inhibits UVA-induced AP-2{alpha} expression in human keratinocytes

    SciTech Connect

    Yu Lei; Venkataraman, Sujatha; Coleman, Mitchell C.; Spitz, Douglas R.; Wertz, Philip W.; Domann, Frederick E. . E-mail: frederick-domann@uiowa.edu

    2006-12-29

    In this study, we found a role for H{sub 2}O{sub 2} in UVA-induced AP-2{alpha} expression in the HaCaT human keratinocyte cell line. UVA irradiation not only increased AP-2{alpha}, but also caused accumulation of H{sub 2}O{sub 2} in the cell culture media, and H{sub 2}O{sub 2} by itself could induce the expression of AP-2{alpha}. By catalyzing the removal of H{sub 2}O{sub 2} from cells through over-expression of GPx-1, induction of AP-2{alpha} expression by UVA was abolished. Induction of transcription factor AP-2{alpha} by UVA had been previously shown to be mediated through the second messenger ceramide. We found that not only UVA irradiation, but also H{sub 2}O{sub 2} by itself caused increases of ceramide in HaCaT cells, and C2-ceramide added to cells induced the AP-2{alpha} signaling pathway. Finally, forced expression of GPx-1 eliminated UVA-induced ceramide accumulation as well as AP-2{alpha} expression. Taken together, these findings suggest that GPx-1 inhibits UVA-induced AP-2{alpha} expression by suppressing the accumulation of H{sub 2}O{sub 2}.

  6. Involvement of lipid peroxidation and organic peroxides in UVA-induced matrix metalloproteinase-1 expression.

    PubMed

    Polte, Tobias; Tyrrell, Rex M

    2004-06-15

    Ultraviolet A (UVA) irradiation causes human skin aging and skin cancer at least partially through the activation of matrix metalloproteinases (MMPs). MMP-1, the interstitial collagenase, is responsible for the degradation of collagen and is involved in tumor progression in human skin. The present study uses human skin fibroblast cells (FEK4) to investigate the involvement of lipid peroxidation and the role of peroxides as possible mediators in MMP-1 activation by UVA. Preincubation with the antioxidants butylated hydroxytoluene and Trolox reduced UVA-dependent MMP-1 upregulation, suggesting that peroxidation of membrane lipids is involved. Blocking the iron-driven generation of lipid peroxides and hydroxyl radicals by different iron chelators led to a decrease in UVA-induced MMP-1 mRNA accumulation. Moreover, modulation of glutathione peroxidase activity by use of the specific inhibitor mercaptosuccinate (MS) or by the depletion of glutathione (using buthionine-S, R-sulfoximine, BSO), enhanced the UVA-dependent MMP-1 response. Finally, UVA irradiation generated a significant increase in intracellular peroxide levels which is augmented by pretreatment of the cells with BSO or MS. Our results demonstrate that lipid peroxidation and the production of peroxides are important events in the signalling pathway of MMP-1 activation by UVA.

  7. Lonicera caerulea fruits reduce UVA-induced damage in hairless mice.

    PubMed

    Vostálová, Jitka; Galandáková, Adéla; Palíková, Irena; Ulrichová, Jitka; Doležal, Dalibor; Lichnovská, Radka; Vrbková, Jana; Rajnochová Svobodová, Alena

    2013-11-05

    UVA photons are less energetic than UVB photons but they are more abundant in solar radiation. Modern tools have shown that UVA light has serious adverse effects on the skin. We investigated the effect of consuming Lonicera caerulea berries on UVA-induced damage in SKH-1 mice. The mice were fed a diet containing L. caerulea berries (10%, w/w) for 14 days before a single UVA (30 J/cm(2)) treatment. Effects on haematological and antioxidant parameters were evaluated 4 and 24h after irradiation. The bioavailability of L. caerulea phenolics was also assessed. Consuming the L. caerulea berry-enriched diet caused reduced malondialdehyde production and increased catalase activity and glutathione levels were found in skin and erythrocytes. UVA-induced NADPH:quinone oxidoreductase-1 and gamma-L-glutamate-L-cysteine ligase protein in skin were reduced in mice fed L. caerulea berries. Enhanced heme oxygenase-1 level in skin, interleukin-17 in plasma and reduced interleukin-12 levels in plasma were found in the mice on the experimental diet. Histological (pyknotic) changes in the nuclei of basal cells induced by UVA exposure were reduced in L. caerulea berry consuming animals. HLPC-MS analysis showed high concentrations of hippuric acid, one of the main metabolites of aromatic amino acids and phenolic compounds, in skin, liver, urine and faeces of mice consuming the berries. Taken together, consumption of L. caerulea berries affords protection from the adverse effects of a single UVA exposure mainly via modulation of antioxidant parameters.

  8. Role of Pin1 in UVA-induced cell proliferation and malignant transformation in epidermal cells

    SciTech Connect

    Han, Chang Yeob; Hien, Tran Thi; Lim, Sung Chul; Kang, Keon Wook

    2011-06-24

    Highlights: {yields} Pin1 expression is enhanced by low energy UVA irradiation in both skin tissues of hairless mice and JB6 C141 epidermal cells. {yields} UVA irradiation increases activator protein-1 activity and cyclin D1 in a Pin1-dependent manner. {yields} UVA potentiates EGF-inducible, anchorage-independent growth of epidermal cells, and this is suppressed by Pin1 inhibition or by anti-oxidant. -- Abstract: Ultraviolet A (UVA) radiation ({lambda} = 320-400 nm) is considered a major cause of human skin cancer. Pin1, a peptidyl prolyl isomerase, is overexpressed in most types of cancer tissues and plays an important role in cell proliferation and transformation. Here, we demonstrated that Pin1 expression was enhanced by low energy UVA (300-900 mJ/cm{sup 2}) irradiation in both skin tissues of hairless mice and JB6 C141 epidermal cells. Exposure of epidermal cells to UVA radiation increased cell proliferation and cyclin D1 expression, and these changes were blocked by Pin1 inhibition. UVA irradiation also increased activator protein-1 (AP-1) minimal reporter activity and nuclear levels of c-Jun, but not c-Fos, in a Pin1-dependent manner. The increases in Pin1 expression and in AP-1 reporter activity in response to UVA were abolished by N-acetylcysteine (NAC) treatment. Finally, we found that pre-exposure of JB6 C141 cells to UVA potentiated EGF-inducible, anchorage-independent growth, and this effect was significantly suppressed by Pin1inhibition or by NAC.

  9. [Is UV-A a cause of malignant melanoma?].

    PubMed

    Moan, J

    1994-03-20

    The first action spectrum for cutaneous malignant melanoma was published recently (2). This spectrum was obtained using the fish Xiphophorus. If the same action spectrum applies to humans, the following statements are true: Sunbathing products (agents to protect against the sun) that absorb UV-B radiation provide almost no protection against cutaneous malignant melanoma. UV-A-solaria are more dangerous than expected so far. If people are determined to use artificial sources of radiation for tanning, they should choose UV-B-solaria rather than UV-A-solaria. Fluorescent tubes and halogen lamps may have weak melanomagnetic effects. Ozone depletion has almost no effect on the incidence rates of CMM, since ozone absorbs very little UV-A radiation. Sunbathing products which contain UV-A-absorbing compounds or neutral filters (like titanium oxide) provide real protection against cutaneous malignant melanoma, at least if they are photochemically inert.

  10. First record of Tenuipalpus uvae De Leon, 1962 (Acari: Tenuipalpidae) in Brazil

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This is the first record of Tenuipalpus uvae De Leon (Tenuipalpidae) in Brazil. Specimens were collected from Spondias mombin L. (Anacardiaceae) in the states of Amapa (Northern Brazil) and Pernambuco (northeast)....

  11. DNA damage in human skin fibroblasts exposed to UVA light used in clinical PUVA treatment

    SciTech Connect

    Bredberg, A.

    1981-06-01

    Human skin fibroblasts were irradiated with a clinically used UVA light source. The doses (1.1 and 3 J/cm2) were similar to those reaching the dermis during clinical PUVA treatment of psoriasis. DNA strand breaks, as determined by alkaline elution, were formed in a dose-dependent way and disappeared within 1 hr of postincubation at 37 degrees C. These findings have clinical implications since UVA-induced DNA damage may be accompanied by mutagenic and tumor promoting effects.

  12. Identification of potentially cytotoxic lesions induced by UVA photoactivation of DNA 4-thiothymidine in human cells

    PubMed Central

    Reelfs, Olivier; Macpherson, Peter; Ren, Xiaolin; Xu, Yao-Zhong; Karran, Peter; Young, Antony R.

    2011-01-01

    Photochemotherapy—in which a photosensitizing drug is combined with ultraviolet or visible radiation—has proven therapeutic effectiveness. Existing approaches have drawbacks, however, and there is a clinical need to develop alternatives offering improved target cell selectivity. DNA substitution by 4-thiothymidine (S4TdR) sensitizes cells to killing by ultraviolet A (UVA) radiation. Here, we demonstrate that UVA photoactivation of DNA S4TdR does not generate reactive oxygen or cause direct DNA breakage and is only minimally mutagenic. In an organotypic human skin model, UVA penetration is sufficiently robust to kill S4TdR-photosensitized epidermal cells. We have investigated the DNA lesions responsible for toxicity. Although thymidine is the predominant UVA photoproduct of S4TdR in dilute solution, more complex lesions are formed when S4TdR-containing oligonucleotides are irradiated. One of these, a thietane/S5-(6-4)T:T, is structurally related to the (6-4) pyrimidine:pyrimidone [(6-4) Py:Py] photoproducts induced by UVB/C radiation. These lesions are detectable in DNA from S4TdR/UVA-treated cells and are excised from DNA more efficiently by keratinocytes than by leukaemia cells. UVA irradiation also induces DNA interstrand crosslinking of S4TdR-containing duplex oligonucleotides. Cells defective in repairing (6-4) Py:Py DNA adducts or processing DNA crosslinks are extremely sensitive to S4TdR/UVA indicating that these lesions contribute significantly to S4TdR/UVA cytotoxicity. PMID:21890905

  13. UVA-induced damage to DNA and proteins: direct versus indirect photochemical processes

    NASA Astrophysics Data System (ADS)

    Girard, P. M.; Francesconi, S.; Pozzebon, M.; Graindorge, D.; Rochette, P.; Drouin, R.; Sage, E.

    2011-01-01

    UVA has long been known for generating an oxidative stress in cells. In this paper we review the different types of DNA damage induced by UVA, i.e. strand breaks, bipyrimidine photoproducts, and oxidatively damaged bases. Emphasis is given to the mechanism of formation that is further illustrated by the presentation of new in vitro data. Examples of oxidation of proteins involved in DNA metabolism are also given.

  14. Lipid nanoparticles based on butyl-methoxydibenzoylmethane: in vitro UVA blocking effect

    NASA Astrophysics Data System (ADS)

    Niculae, G.; Lacatusu, I.; Badea, N.; Meghea, A.

    2012-08-01

    The aim of the present study was to obtain efficient lipid nanoparticles loaded with butyl-methoxydibenzoylmethane (BMDBM) in order to develop cosmetic formulations with enhanced UVA blocking effect. For this purpose, two adequate liquid lipids (medium chain triglycerides and squalene) have been used in combination with two solid lipids (cetyl palmitate and glyceryl stearate) in order to create appropriate nanostructured carriers with a disordered lipid network able to accommodate up to 1.5% BMDBM. The lipid nanoparticles (LNs) were characterized in terms of particle size, zeta potential, entrapment efficiency, loading capacity and in vitro UVA blocking effect. The efficiency of lipid nanoparticles in developing some cosmetic formulations has been evaluated by determining the in vitro erythemal UVA protection factor. In order to quantify the photoprotective effect, some selected cream formulations based on BMDBM-LNs and a conventional emulsion were exposed to photochemical UV irradiation at a low energy to simulate the solar energy during the midday. The results obtained demonstrated the high ability of cream formulations based on BMDBM-LNs to absorb more than 96% of UVA radiation. Moreover, the developed cosmetic formulations manifest an enhanced UVA blocking effect, the erythemal UVA protection factor being four times higher than those specific to conventional emulsions.

  15. UVA radiation impairs phenotypic and functional maturation of human dermal dendritic cells.

    PubMed

    Furio, Laetitia; Berthier-Vergnes, Odile; Ducarre, Blandine; Schmitt, Daniel; Peguet-Navarro, Josette

    2005-11-01

    There is now strong evidence that the ultraviolet A (UVA) part of the solar spectrum contributes to the development of skin cancers. Its effect on the skin immune system, however, has not been fully investigated. Here, we analyzed the effects of UVA radiation on dermal dendritic cells (DDC), which, in addition, provided further characterization of these cells. Dermal sheets were obtained from normal human skin and irradiated, or not, with UVA at 2 or 12 J per cm2. After a 2 d incubation, the phenotype of emigrant cells was analyzed by double immunostaining and flow cytometry. Results showed that migratory DDC were best characterized by CD1c expression and that only few cells co-expressed the Langerhans cell marker Langerin. Whereas the DC extracted from the dermis displayed an immature phenotype, emigrant DDC showed increased expression of HLA-DR and acquired co-stimulation and maturation markers. We showed here that UVA significantly decreased the number of viable emigrant DDC, a process related to increased apoptosis. Furthermore, UVA irradiation impaired the phenotypic and functional maturation of migrating DDC into potent antigen-presenting cells, in a concentration-dependent manner. The results provide further evidence that UVA are immunosuppressive and suggest an additional mechanism by which solar radiation impairs immune response.

  16. Preventive effect of dietary astaxanthin on UVA-induced skin photoaging in hairless mice

    PubMed Central

    Komatsu, Toshiyuki; Sasaki, Suguru; Manabe, Yuki; Hirata, Takashi

    2017-01-01

    Astaxanthin, a carotenoid found mainly in seafood, has potential clinical applications due to its antioxidant activity. In this study, we evaluated the effect of dietary astaxanthin derived from Haematococcus pluvialis on skin photoaging in UVA-irradiated hairless mice by assessing various parameters of photoaging. After chronic ultraviolet A (UVA) exposure, a significant increase in transepidermal water loss (TEWL) and wrinkle formation in the dorsal skin caused by UVA was observed, and dietary astaxanthin significantly suppressed these photoaging features. We found that the mRNA expression of lympho-epithelial Kazal-type-related inhibitor, steroid sulfatase, and aquaporin 3 in the epidermis was significantly increased by UVA irradiation for 70 days, and dietary astaxanthin significantly suppressed these increases in mRNA expression to be comparable to control levels. In the dermis, the mRNA expression of matrix metalloprotease 13 was increased by UVA irradiation and significantly suppressed by dietary astaxanthin. In addition, HPLC-PDA analysis confirmed that dietary astaxanthin reached not only the dermis but also the epidermis. Our results indicate that dietary astaxanthin accumulates in the skin and appears to prevent the effects of UVA irradiation on filaggrin metabolism and desquamation in the epidermis and the extracellular matrix in the dermis. PMID:28170435

  17. The relative roles of DNA damage induced by UVA irradiation in human cells.

    PubMed

    Cortat, Barbara; Garcia, Camila Carrião Machado; Quinet, Annabel; Schuch, André Passaglia; de Lima-Bessa, Keronninn Moreno; Menck, Carlos Frederico Martins

    2013-08-01

    UVA light (320-400 nm) represents approximately 95% of the total solar UV radiation that reaches the Earth's surface. UVA light induces oxidative stress and the formation of DNA photoproducts in skin cells. These photoproducts such as pyrimidine dimers (cyclobutane pyrimidine dimers, CPDs, and pyrimidine (6-4) pyrimidone photoproducts, 6-4PPs) are removed by nucleotide excision repair (NER). In this repair pathway, the XPA protein is recruited to the damage removal site; therefore, cells deficient in this protein are unable to repair the photoproducts. The aim of this study was to investigate the involvement of oxidative stress and the formation of DNA photoproducts in UVA-induced cell death. In fact, similar levels of oxidative stress and oxidised bases were detected in XP-A and NER-proficient cells exposed to UVA light. Interestingly, CPDs were detected in both cell lines; however, 6-4PPs were detected only in DNA repair-deficient cells. XP-A cells were also observed to be significantly more sensitive to UVA light compared to NER-proficient cells, with an increased induction of apoptosis, while necrosis was similarly observed in both cell lines. The induction of apoptosis and necrosis in XP-A cells using adenovirus-mediated transduction of specific photolyases was investigated and we confirm that both types of photoproducts are the primary lesions responsible for inducing cell death in XP-A cells and may trigger the skin-damaging effects of UVA light, particularly skin ageing and carcinogenesis.

  18. Comparison of Solar UVA and UVB Radiation Measured in Selangor, Malaysia

    NASA Astrophysics Data System (ADS)

    Kamarudin, S. U.; Gopir, G.; Yatim, B.; Sanusi, H.; Mahmud, P. S. Megat; Choo, P. Y.

    2010-07-01

    The solar ultraviolet A (UVA) radiation data was measured at Physics Building, Universiti Kebangsaan Malaysia (2°55' N, 101°46' E, 50m asl) by the Xplorer GLX Pasco that connected to UVA Light sensor. The measured solar UVA data were compared with the total daily solar ultraviolet B (UVB) radiation data recorded by the Malaysian Metrological Department at Petaling Jaya, Malaysia (3° 06' N, 101° 39' E, 50m asl) for 18 days in year 2007. The daily total average of UVA radiation received is (298±105) kJm-2 while the total daily maximum is (600±56) kJm-2. From the analysis, it shows that the values of UVA radiation data were higher than UVB radiation data with the average ratio of 6.41% between 3-14%. A weak positive correlation was found (the correlation coefficient, r, is 0.22). The amount of UVA radiation that reached the earth surface is less dependence on UVB radiation and the factors were discussed.

  19. Comparison of Solar UVA and UVB Radiation Measured in Selangor, Malaysia

    SciTech Connect

    Kamarudin, S. U.; Gopir, G.; Yatim, B.; Sanusi, H.; Mahmud, P. S. Megat; Choo, P. Y.

    2010-07-07

    The solar ultraviolet A (UVA) radiation data was measured at Physics Building, Universiti Kebangsaan Malaysia (2 degree sign 55' N, 101 degree sign 46' E, 50m asl) by the Xplorer GLX Pasco that connected to UVA Light sensor. The measured solar UVA data were compared with the total daily solar ultraviolet B (UVB) radiation data recorded by the Malaysian Metrological Department at Petaling Jaya, Malaysia (3 degree sign 06' N, 101 degree sign 39' E, 50m asl) for 18 days in year 2007. The daily total average of UVA radiation received is (298{+-}105) kJm{sup -2} while the total daily maximum is (600{+-}56) kJm{sup -2}. From the analysis, it shows that the values of UVA radiation data were higher than UVB radiation data with the average ratio of 6.41% between 3-14%. A weak positive correlation was found (the correlation coefficient, r, is 0.22). The amount of UVA radiation that reached the earth surface is less dependence on UVB radiation and the factors were discussed.

  20. Epidermal changes in human skin following irradiation with either UVB or UVA

    SciTech Connect

    Pearse, A.D.; Gaskell, S.A.; Marks, R.

    1987-01-01

    We have demonstrated previously that following UVB irradiation to normal volunteers there is an increase in epidermal and stratum corneum thickness and an increase in the thymidine autoradiographic labeling index. These changes are coupled with alterations in epidermal glucose-6-phosphate dehydrogenase and succinic dehydrogenase activities, despite the absence of erythema clinically. The use of a sunscreen did not completely prevent these changes. In this study, we have examined the effects of repeated irradiation of human skin with either UVB or UVA alone in order to compare the changes produced in the epidermis and to ascertain whether UVA irradiation could cause these. Irradiation with either UVB or UVA alone was found to increase the mean epidermal thickness, the mean stratum corneum thickness, and mean keratinocyte height significantly. Glucose-6-phosphate dehydrogenase activity was significantly increased throughout the epidermis, and succinic dehydrogenase activity was significantly decreased. The autoradiographic labeling index was significantly increased following UVB irradiation but not following UVA irradiation. These results demonstrate that UVA alone can have a direct effect on epidermal morphology and metabolism, suggesting that protection of skin from UV radiation should include adequate protection from UVA.

  1. Effects of solar ultraviolet photons on mammalian cell DNA. [UVA (320-400 nm):a2

    SciTech Connect

    Peak, M.J.; Peak, J.G.

    1991-01-01

    This document presents information on the possible mechanisms of carcinogenesis caused by UVA (ultraviolet radiation in the 320--400 nm region). Most studies showing the carcinogenic effects of ultraviolet light have concentrated on UVB (280--320 nm). UVA had been considered harmless even though it penetrates biological tissues better than UVB. Recently, it has become apparent that UVA is also capable of causing damage to cellular DNA. This was unexpected because the DNA UV absorption spectrum indicates a negligible probability that photons of wavelengths longer than 320 nm will be directly absorbed. The most common defects induced in DNA by UVB are pyrimidine photoproducts, such as thymidine dimers. UVA photons produce defects resembling those caused by ionizing radiations: single- and double-strand breaks, and DNA-protein crosslinks. This paper also discusses the role of DNA repair mechanisms in UVA-induced defects and the molecular mechanisms of UVA damage induction. 38 refs. (MHB)

  2. Comparison of the role of attachment, aggregation and internalisation of microorganisms in UVC and UVA (solar) disinfection.

    PubMed

    Bichai, Françoise; Léveillé, Simon; Barbeau, Benoit

    2011-01-01

    In this comparative study, the impact of two microbial protective mechanisms against simulated UVA disinfection was assessed by using protocols previously developed for UVC disinfection assays. (i) The impact of natural microorganism aggregation and attachment to particles was assessed by targeting total coliform bacteria in natural surface water samples. (ii) The impact of bacteria internalisation by zooplankton was assessed by using C. elegans nematodes as a model host and E. coli as a bacterial target for UVA inactivation. Dispersion of natural aggregates by blending prior to UVA exposure was shown to enhance the inactivation rate of total coliforms as compared to untreated raw water. Removal of particles by an 8-microm membrane filtration did not improve UVA disinfection efficiency. Twenty-four per cent of the highest applied UVA fluence was found to reach internalised E. coli in nematodes. Both aggregation and internalisation showed similar impact as protective mechanisms against UVA and UVC bacterial inactivation.

  3. NASA-UVA light aerospace alloy and structures technology program

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.; Haviland, John K.; Herakovich, Carl T.; Pilkey, Walter D.; Pindera, Marek-Jerzy; Thornton, Earl A.; Stoner, Glenn E.; Swanson, Robert E.; Wawner, Franklin E., Jr.; Wert, John A.

    1989-01-01

    The report on progress achieved in accomplishing of the NASA-UVA Light Aerospace Alloy and Structures Technology Program is presented. The objective is to conduct interdisciplinary graduate student research on the performance of next generation, light weight aerospace alloys and associated thermal gradient structures in close collaboration with researchers. The efforts will produce basic understanding of material behavior, new monolithic and composite alloys, processing methods, solid and fluid mechanics analyses, measurement advances, and a pool of educated graduate students. The presented accomplishments include: research on corrosion fatigue of Al-Li-Cu alloy 2090; research on the strengthening effect of small In additions to Al-Li-Cu alloys; research on localized corrosion of Al-Li alloys; research on stress corrosion cracking of Al-Li-Cu alloys; research on fiber-matrix reaction studies (Ti-1100 and Ti-15-3 matrices containing SCS-6, SCS-9, and SCS-10 fibers); and research on methods for quantifying non-random particle distribution in materials that has led to generation of a set of computer programs that can detect and characterize clusters in particles.

  4. Membrane lipid peroxidation by UV-A: Mechanism and implications

    SciTech Connect

    Bose, B.; Agarwal, S.; Chatterjee, S.N. )

    1990-10-01

    UV-A produced a dose-dependent linear increase of lipid peroxidation in liposomal membrane, as detected by the assay of (i) conjugated dienes, (ii) lipid hydroperoxides, (iii) malondialdehydes (MDA), and (iv) the fluorescent adducts formed by the reaction of MDA with glycine and also a linear dose-dependent increase of ({sup 14}C)glucose efflux from the liposomes. UV-A-induced MDA production could not be inhibited by any significant degree by sodium formate, dimethyl sulfoxide, EDTA, or superoxide dismutase but was very significantly inhibited by butylated hydroxytoluene, alpha-tocopherol, sodium azide, L-histidine, dimethylfuran, and beta-carotene. MDA formation increased with an increase in the D{sub 2}O content in water, leading to a maximal amount of nearly 50% enhancement of lipid peroxidation in 100% D{sub 2}O vis-a-vis water used as dispersion medium. The experimental findings indicate the involvement of singlet oxygen as the initiator of the UV-A-induced lipid peroxidation.

  5. Growth and metabolism in the Antarctic brachiopod Liothyrella uva

    PubMed Central

    Peck, L. S.; Brockington, S.; Brey, T.

    1997-01-01

    Summer and winter growth rates were assessed separately for a population of the Antarctic brachiopod Liothyrella uva between early January 1992 and December 1993. Annual shell growth rates (1.6-2.3 mm yr-1 for a 5 mm individual; 0.96-1.44 mm -1 for a 20 mm specimen) were two to six times slower than those reported for temperate species. Growth in specimens less than 20 mm in length was faster in 1992 than in 1993, although differences between years over the whole size range were not significant. Surprisingly, growth was much faster in winter periods than during the summers. A 5 mm long individual grew five times faster in winter than in summer, and for a 20 mm long specimen the difference was 13 times. This runs contrary to current ideas on the effects of seasonality on the biology of polar marine invertebrates, but may be an effect of maximizing the efficiency of resource utilization. Comparisons with previous work showed shell growth to be decoupled from periods of tissue mass increase, and also from the main period of phytoplankton productivity. Oxygen consumption of 75 of the specimens used in the growth study was measured to test the hypothesis that basal metabolic rates should be inversely correlated with growth rates. Unexpectedly, an analysis of residuals produced no significant relationship, positive or negative, between growth rate and basal metabolism (F = 1.37, p=0.25, n = 75).

  6. Pentosidine in advanced glycation end-products (AGEs) during UVA irradiation generates active oxygen species and impairs human dermal fibroblasts.

    PubMed

    Okano, Y; Masaki, H; Sakurai, H

    2001-08-01

    Our previous study reported that advanced glycation end-products (AGE)-modified BSA produced active oxygen species, *O2-, H2O2, and *OH under UVA irradiation and enhanced the cytotoxicity of UVA light. We examined whether pentosidine in AGE-modified BSA was involved in one of the mechanisms generating the active oxygen species. In biological investigations, fibroblasts exposed to UVA (20 J/cm2) in the presence of pentosidine-rich compounds (PRCs), which were prepared with L-arginine, L-lysine and glucose, showed a time-dependent leakage of the cytosolic enzyme LDH. In addition, release of LDH was suppressed by addition of DMSO and deferoxamine under UVA irradiation. From these results, it was determined that PRCs exposed to UVA damaged the plasma membrane of human dermal fibroblasts due to the conversion of *OH from H2O2 via a Fenton-like reaction. These features of PRCs exposed to UVA were consistent with those of AGE-modified BSA. In an ESR study, PRCs under UVA irradiation yielded DMPO-OH (DMPO-OH adduct) using DMPO as a spin-trapping reagent. *O2- generation from UVA-irradiated PRCs was also indicated by the combination of NBT reduction and SOD. When PRCs were exposed to UVA light controlled with a long-pass filter, WG-360, it was found that their production of *O2- was prohibited less than 50% in the NBT reduction assay. The *O2- production profile of PRCs depending on the wavelength of UVA light was similar to that of AGE-modified BSA. Furthermore, it was found that the H2O2 level was increased by PRCs exposed to UVA. These results indicated that pentosidine is an important factor of AGE-modified BSA in active oxygen generation under UVA irradiation.

  7. Adaptive antioxidant response protects dermal fibroblasts from UVA-induced phototoxicity.

    PubMed

    Meewes, C; Brenneisen, P; Wenk, J; Kuhr, L; Ma, W; Alikoski, J; Poswig, A; Krieg, T; Scharffetter-Kochanek, K

    2001-02-01

    In response to the attack of reactive oxygen species (ROS) produced upon UV irradiation, the skin has developed a complex antioxidant defense system. Here we report that, in addition to the previously published induction of manganese superoxide dismutase (MnSOD) activity, single and, to a higher extent, repetitive low-dose UVA irradiation also leads to a substantial upregulation of glutathione peroxidase (GPx) activity. This concomitant adaptive response of two antioxidant enzymes acting in the same detoxification pathway coincided with the protection from high-UVA-dose-induced cytotoxicity conferred by low-dose UVA preirradiation. Whereas an interval of 24 h did not, an interval of 12 h did lead to the induction of MnSOD activity and, under selenium-supplemented conditions, of GPx activity as well, conferring definite cellular protection from UVA-induced phototoxicity. Moreover, under selenium-deficient conditions, which abrogate the UVA-mediated induction of GPx activity, adaptive protection against the cytotoxic effects of high UVA doses was significantly lower compared with selenium supplementation. Isolated 4.6-fold overexpression of MnSOD activity in stably transfected fibroblasts led to specific resistance from UVA-mediated phototoxicity under selenium-deficient conditions. Collectively, these data indicate that the concomitant induction of MnSOD and GPx activity is related to the optimal adaptive protection from photooxidative damage. This adaptive antioxidant protection clearly depends on the irradiation interval and a sufficient selenium concentration, findings that may have important implications for the improvement of photoprotective and phototherapeutic strategies in medicine.

  8. Responses of Crepis japonica induced by supplemental blue light and UV-A radiation.

    PubMed

    Constantino, L F da S; Nascimento, L B Dos S; Casanova, L M; Moreira, N Dos S; Menezes, E A; Esteves, R L; Costa, S S; Tavares, E S

    2017-02-15

    Crepis japonica (L.) D.C. (Asteraceae), a weed with antioxidant, antiallergenic, antiviral and antitumor properties displays both medicinal properties and nutritional value. This study aims to assess the effects of a supplementation of blue light and UV-A radiation on the growth, leaf anatomical structure and phenolic profile of the aerial parts of Crepis japonica. Plants were grown under two light treatments: W (control - white light), W + B (white light supplemented with blue light) and W + UV-A (white light supplemented with UV-A radiation). We recorded the length, width, and weight of fresh and dry leaves, the thickness of the epidermis and mesophyll, and stomata density. The phenolic profiles of the aqueous extracts of the aerial parts were analyzed by HPLC-DAD. There was an increase in the leaf size, stomatal density, and phenolic production, and a thickening of the mesophyll and epidermis. UV-A radiation increased the phenolic production more than blue light. Blue light and UV-A radiation both improved the production of caffeic acid by about 6 and 3 times, respectively, in comparison to control. This compound was first reported as a constituent of the extract from the aerial parts together with caftaric acid. UV-A also promoted the production of chlorogenic acid (about 1.5 times in comparison to the control). We observed that the morphological and chemical parameters of C. japonica are modified in response to blue light and UV-A radiation, which can be used as tools in the cultivation of this species in order to improve its medicinal properties and nutritional value.

  9. Differential Activation of Signaling Pathways by UVA and UVB Radiation in Normal Human Epidermal Keratinocytes†

    PubMed Central

    Syed, Deeba N.; Afaq, Farrukh; Mukhtar, Hasan

    2012-01-01

    Ultraviolet (UV) radiation from the solar spectrum is a major etiological factor for many cutaneous pathologies including cancer. By understanding changes in cell signaling pathways induced by UVA and UVB, novel strategies for prevention and treatment of UV-related pathologies could be developed. However, much of the information in the literature from various laboratories cannot cross talk because of difficulties associated with the use of ill-defined light sources and physiologically irrelevant light dosimetry. Herein, we have assessed the effect of exposure of normal human epidermal keratinocytes (NHEK) to UVA (2 and 4 J cm−2) or UVB (20 and 40 mJ cm−2) radiation. Employing western blot analysis, we found that exposure of NHEK to UVB, but not UVA, phosphorylates JNK1/2 at Th183/Tyr185, STAT3 at Ser727, AKT at Ser473 and increases c-Fos expression, whereas exposure to UVA, but not UVB, phosphorylates AKT at Thr308. UVB as well as UVA exposure leads to increased phosphorylation of (1) ERK1/2 at Th202/Tyr204; (2) p38 at Th180/Tyr204; (3) STAT3 at Tyr705; (4) mTOR at Thr2448; and (v) p70S6k at Thr421/Ser424; enhanced expression of PI3K (p85) and c-jun; and nuclear translocation of NFκB proteins. These findings could be considered as a beginning for understanding the differential effects of UVA and UVB in the human skin and may have implications both with respect to risk assessment from exposure to solar UV radiation, and to target interventions against signaling events mediated by UVA and UVB. PMID:22335604

  10. Sunscreens, skin photobiology, and skin cancer: the need for UVA protection and evaluation of efficacy.

    PubMed

    Gasparro, F P

    2000-03-01

    Sunscreens are ultraviolet radiation (UVR)-absorbing chemicals that attenuate the amount and nature of UVR reaching viable cells in the skin. They are selected and tested for their ability to prevent erythema. No sunscreen prevents photodamage, as it has been demonstrated that suberythemal doses of UVR cause a variety of molecular changes (including DNA damage) in these cells. Furthermore, the spectrum of UVR reaching viable cells is altered by topically applied sunscreen. In this review, the basic aspects of sunscreens and skin photobiology are reviewed briefly. Although there can be no question concerning the efficacy of sunscreens for the prevention of erythema, questions remain because of the possible cumulative effects of chronic suberythemal doses and the increased exposure of skin cells to longer UVR wavelengths. The current major issue surrounding sunscreens involves their ability to protect skin cells against the effects of UVA radiation. These UVA effects may be direct damage (base oxidations) or effects on the skin immune system, yet there is no uniformly accepted method for the evaluation of UVA protection. This review is focused primarily on the latter topic covering action spectra that implicate the need for UVA protection. In addition, in vivo and in vitro methods proposed for the evaluation of candidate sunscreen formulations of UVA protective ability are reviewed. Finally, revisions in the terminology used to describe the protection afforded by sunscreens are suggested. It is proposed that SPF ("sun" protection factor) be renamed "sunburn" protection factor and that "critical wavelength" be designated "long wave index."

  11. Growth of antarctic cyanobacteria under ultraviolet radiation: UVA counteracts UVB inhibition

    SciTech Connect

    Quesada, A. |; Mouget, J.L.; Vincent, W.F.

    1995-04-01

    A mat-forming cyanobacterium (Phormidium murayi West and West) isolated from an ice-shelf pond in Antarctica was grown under white light combined with a range of UVA and UVB irradiance. The 4-day growth rate decreased under increasing ultraviolet (UV) radiation, with a ninefold greater response to UVB relative to UVA. In vivo absorbance spectra showed that UVA and to a greater extent UVB caused a decrease in phycocyanin/chlorophyll a and an increase in carotenoids/chlorophyll a. The phycocyanin/chlorophyll a ratio was closely and positively correlated to the UVB-inhibited growth rate. Under fixed spectral gradients of UV radiation, the growth inhibition effect was dominated by UVB. However, at specific UVB irradiances the inhibition of growth depended on the ratio of UVB to UVA, and growth rates increased linearly with increasing UVA. These results are consistent with the view that UVB inhibition represents the balance between damage and repair processes that are each controlled by separate wavebands. They also underscore the need to consider UV spectral balance in laboratory and field assays of UVB toxicity. 49 refs., 6 figs.

  12. Protective role of extracellular catalase (KatA) against UVA radiation in Pseudomonas aeruginosa biofilms.

    PubMed

    Pezzoni, Magdalena; Pizarro, Ramón A; Costa, Cristina S

    2014-02-05

    One of the more stressful factors that Pseudomonas aeruginosa must face in nature is solar UVA radiation. In this study, the protective role of KatA catalase in both planktonic cells and biofilms of P. aeruginosa against UVA radiation was determined by using the wild-type (PAO1) and an isogenic catalase deficient strain (katA). The katA strain was more sensitive than the wild-type, especially in the case of biofilms. Moreover, the wild-type biofilm was more resistant than its planktonic counterpart, but this was not observed in the katA strain. Striking KatA activity was detected in the matrix of katA(+) strains, and to our knowledge, this is the first report of this activity in the matrix of P. aeruginosa biofilms. Provision of bovine catalase or KatA to the matrix of a katA biofilm significantly increased its UVA tolerance, demonstrating that extracellular KatA is essential to optimal defense against UVA in P. aeruginosa biofilms. Efficiency of photocatalytic treatments using TiO2 and UVA was lower in biofilms than in planktonic cells, but KatA and KatB catalases seem not to be responsible for the higher resistance of the sessile cells to this treatment.

  13. Singlet Oxygen-Mediated Oxidation during UVA Radiation Alters the Dynamic of Genomic DNA Replication

    PubMed Central

    Graindorge, Dany; Martineau, Sylvain; Machon, Christelle; Arnoux, Philippe; Guitton, Jérôme; Francesconi, Stefania; Frochot, Céline; Sage, Evelyne; Girard, Pierre-Marie

    2015-01-01

    UVA radiation (320–400 nm) is a major environmental agent that can exert its deleterious action on living organisms through absorption of the UVA photons by endogenous or exogenous photosensitizers. This leads to the production of reactive oxygen species (ROS), such as singlet oxygen (1O2) and hydrogen peroxide (H2O2), which in turn can modify reversibly or irreversibly biomolecules, such as lipids, proteins and nucleic acids. We have previously reported that UVA-induced ROS strongly inhibit DNA replication in a dose-dependent manner, but independently of the cell cycle checkpoints activation. Here, we report that the production of 1O2 by UVA radiation leads to a transient inhibition of replication fork velocity, a transient decrease in the dNTP pool, a quickly reversible GSH-dependent oxidation of the RRM1 subunit of ribonucleotide reductase and sustained inhibition of origin firing. The time of recovery post irradiation for each of these events can last from few minutes (reduction of oxidized RRM1) to several hours (replication fork velocity and origin firing). The quenching of 1O2 by sodium azide prevents the delay of DNA replication, the decrease in the dNTP pool and the oxidation of RRM1, while inhibition of Chk1 does not prevent the inhibition of origin firing. Although the molecular mechanism remains elusive, our data demonstrate that the dynamic of replication is altered by UVA photosensitization of vitamins via the production of singlet oxygen. PMID:26485711

  14. UVA1 phototherapy in the treatment of palmoplantar pustulosis: a pilot prospective study.

    PubMed

    Su, Li-Na; Xu, Xin; Tang, Li; Yu, Ning; Ding, Yang-Feng

    2016-11-01

    Palmoplantar pustulosis (PPP) is recalcitrant to traditional topical and systemic therapies. Ultraviolet A1 (UVA1) phototherapy, a new therapeutic approach, has recently been shown good efficacy in the treatment of PPP. The purpose of this study was to evaluate the efficacy and safety of UVA1 therapy for the treatment of PPP. Patients with PPP were treated with UVA1 irradiation three times a week for up to 30 sessions and had a 3-month follow-up visit. UVA1 therapy was conducted with a fixed dose (80 J/cm(2)). Clinical evaluation was based on the Palmoplantar Pustular Psoriasis Area and Severity Index (PPPASI) score. Totally, 62 patients completed the study. The mean PPPASI score decreased from a baseline value of 9.4 ± 2.8 to a value of 4.9 ± 2.4 at 15 sessions, 1.7 ± 1.9 at 30 sessions, and 2.0 ± 2.1 at follow-up visit. A reduction of 75 % in the PPPASI score was observed in 4 (6.5 %) patients at 15 sessions and 45 (72.6 %) patients at 30 sessions. The adverse effects were limited including burning sensation, pruritus, and hyperpigmentation. UVA1 is an effective therapy for PPP with mild side effects.

  15. Impacts of antibiotics on in vitro UVA-susceptibility of human skin fibroblasts.

    PubMed

    Le Gall, Rozenn; Marchand, Cécile; Rees, Jean-François

    2005-01-01

    Many studies of UVA-induced cell damage use skin cells obtained during plastic surgery. As the skin is contaminated by micro-organisms, antibiotics need to be added to primary skin cell culture media. This study analysed the impact of the most widely used agents, penicillin, streptomycin, and amphotericin B deoxycholate (amB), on UVA-irradiated human skin fibroblasts. The results show that the presence of amB in cell culture media increases the susceptibility of fibroblasts to UVA and the intracellular level of reactive oxygen species, even when cells are irradiated in amB-free saline. This photosensitising effect of amB can be prevented if the antifungal agent is removed from the culture medium at least 24 hours before irradiation. Moreover, the use of streptomycin during cell culture partly protects cells against the UVA-induced mortality linked to amB. Acellular tests on lipid micelles suggest that this protective effect could result from an inhibition of lipid peroxidation by the antibacterial agent. In conclusion, antibiotics should be used with care in cell culture media if the cells are to be used in physiological studies of fine mechanisms in UVA-susceptibility of skin cells. In other cases, cells should be maintained in antibiotic-free media for 24 hours before irradiation.

  16. Sunscreens, skin photobiology, and skin cancer: the need for UVA protection and evaluation of efficacy.

    PubMed Central

    Gasparro, F P

    2000-01-01

    Sunscreens are ultraviolet radiation (UVR)-absorbing chemicals that attenuate the amount and nature of UVR reaching viable cells in the skin. They are selected and tested for their ability to prevent erythema. No sunscreen prevents photodamage, as it has been demonstrated that suberythemal doses of UVR cause a variety of molecular changes (including DNA damage) in these cells. Furthermore, the spectrum of UVR reaching viable cells is altered by topically applied sunscreen. In this review, the basic aspects of sunscreens and skin photobiology are reviewed briefly. Although there can be no question concerning the efficacy of sunscreens for the prevention of erythema, questions remain because of the possible cumulative effects of chronic suberythemal doses and the increased exposure of skin cells to longer UVR wavelengths. The current major issue surrounding sunscreens involves their ability to protect skin cells against the effects of UVA radiation. These UVA effects may be direct damage (base oxidations) or effects on the skin immune system, yet there is no uniformly accepted method for the evaluation of UVA protection. This review is focused primarily on the latter topic covering action spectra that implicate the need for UVA protection. In addition, in vivo and in vitro methods proposed for the evaluation of candidate sunscreen formulations of UVA protective ability are reviewed. Finally, revisions in the terminology used to describe the protection afforded by sunscreens are suggested. It is proposed that SPF ("sun" protection factor) be renamed "sunburn" protection factor and that "critical wavelength" be designated "long wave index." PMID:10698724

  17. Singlet Oxygen-Mediated Oxidation during UVA Radiation Alters the Dynamic of Genomic DNA Replication.

    PubMed

    Graindorge, Dany; Martineau, Sylvain; Machon, Christelle; Arnoux, Philippe; Guitton, Jérôme; Francesconi, Stefania; Frochot, Céline; Sage, Evelyne; Girard, Pierre-Marie

    2015-01-01

    UVA radiation (320-400 nm) is a major environmental agent that can exert its deleterious action on living organisms through absorption of the UVA photons by endogenous or exogenous photosensitizers. This leads to the production of reactive oxygen species (ROS), such as singlet oxygen (1O2) and hydrogen peroxide (H2O2), which in turn can modify reversibly or irreversibly biomolecules, such as lipids, proteins and nucleic acids. We have previously reported that UVA-induced ROS strongly inhibit DNA replication in a dose-dependent manner, but independently of the cell cycle checkpoints activation. Here, we report that the production of 1O2 by UVA radiation leads to a transient inhibition of replication fork velocity, a transient decrease in the dNTP pool, a quickly reversible GSH-dependent oxidation of the RRM1 subunit of ribonucleotide reductase and sustained inhibition of origin firing. The time of recovery post irradiation for each of these events can last from few minutes (reduction of oxidized RRM1) to several hours (replication fork velocity and origin firing). The quenching of 1O2 by sodium azide prevents the delay of DNA replication, the decrease in the dNTP pool and the oxidation of RRM1, while inhibition of Chk1 does not prevent the inhibition of origin firing. Although the molecular mechanism remains elusive, our data demonstrate that the dynamic of replication is altered by UVA photosensitization of vitamins via the production of singlet oxygen.

  18. Adhesion of leukocytes to dermal endothelial cells is induced after single-dose, but reduced after repeated doses of UVA.

    PubMed

    Heckmann, M; Pirthauer, M; Plewig, G

    1997-12-01

    Approximately 20-50% of ultraviolet A (UVA) irradiation delivered to the skin surface may reach the human dermal microvascular endothelial cells (HDMEC) that play a pivotal role in cellular inflammatory tissue; however, the pathophysiologic role of HDMEC in UVA-induced skin changes is largely unknown. Based on previous in vivo and in vitro studies revealing UVA-induced expression of endothelial adhesion molecules, we studied isolated HDMEC under various conditions in order to further delineate the impact of UVA on these cells. The expression of cell adhesion molecules was determined by flow cytometry and the resulting changes of stable adhesion of leukocytes to endothelial cells were quantitated for granulocytes, lymphocytes, and monocytes using a newly developed multicellular adhesion assay. Additionally, antibody blocking experiments were performed to delineate the role of individual cell adhesion molecules in UVA-induced leukocyte adherence. High-dose polychromatic UVA (25 J per cm2, maximal emission at 375 nm) induced intercellular adhesion molecule-1 and E-selectin with different kinetics but correlating the adhesion of leukocyte subsets. This effect subsided, however, in the course of 3-6 daily applied UVA doses. Moreover, pro-inflammatory cytokine challenge by tumor necrosis factor-alpha and interleukin-1-alpha resulted in significantly weaker induction of intercellular adhesion molecule-1 and E-selectin in repeatedly UVA-exposed HDMEC. Differential quantitation of peripheral blood derived granulocytes, lymphocytes, and monocytes revealed reduced adhesion particularly of lymphocytes followed by monocytes and granulocytes compared with leukocyte adhesion to nonirradiated but cytokine-stimulated HDMEC. It is concluded that UVA substantially influences endothelial cell adhesion molecules expression and thus directly interferes with leukocyte adhesion to endothelial cells. Divergent UVA-induced effects in this respect can be attributed to the mode of UV exposure

  19. Inactivation of bacteria via photosensitization of vitamin K3 by UV-A light.

    PubMed

    Xu, Fei; Vostal, Jaroslav G

    2014-09-01

    This study investigated inactivation of bacteria with ultraviolet light A irradiation in combination with vitamin K3 as a photosensitizer. Six bacteria including Bacillus cereus, Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, Klebsiella pneumoniae, and Escherichia coli suspended in vitamin K3 aqueous solution were exposed to ultraviolet light A. Five of six bacteria, with the exception of Pseudomonas aeruginosa, were reduced by eight logs with 1600 μM of vitamin K3 and 5.8 J cm(-2) UV-A irradiation. Pseudomonas aeruginosa was reduced by four logs under these conditions. Reactive oxygen species including singlet oxygen, hydroxyl radical and superoxide anion radical were generated in vitamin K3 aqueous solution under UV-A irradiation. These results suggest that vitamin K3 and UV-A irradiation may be effective for bacterial inactivation in environmental and medical applications.

  20. Chrysin protects epidermal keratinocytes from UVA- and UVB-induced damage.

    PubMed

    Wu, Nan-Lin; Fang, Jia-You; Chen, Marcelo; Wu, Chia-Jung; Huang, Chieh-Chen; Hung, Chi-Feng

    2011-08-10

    Chrysin (5,7-dihydroxyflavone), a natural flavonoid occurring in various plants and foods such as propolis and honey, reportedly opposes inflammation and carcinogenesis, but has rarely been applied in skin care. This study, therefore, aimed to explore the roles of chrysin in protection against UV-induced damage in HaCaT keratinocytes. Results showed that chrysin can attenuate apoptosis, reactive oxygen species (ROS) production, and cyclooxygenase 2 (COX-2) expression induced by UVB and UVA. Chrysin predominantly reversed the down-regulation of aquaporin 3 (AQP-3) by UVB. It predominantly reversed JNK activation and also mildly inhibited p38 activation triggered by UVA and UVB. Animal studies revealed that chrysin's topical application demonstrated efficient percutaneous absorption and no skin irritation. Overall, results demonstrated significant benefits of chrysin on the protection of keratinocytes against UVA- and UVB-induced injuries and suggested its potential use in skin photoprotection.

  1. Changes of MMP-1 and collagen type Ialpha1 by UVA, UVB and IRA are differentially regulated by Trx-1.

    PubMed

    Buechner, Nicole; Schroeder, Peter; Jakob, Sascha; Kunze, Kerstin; Maresch, Tanja; Calles, Christian; Krutmann, Jean; Haendeler, Judith

    2008-07-01

    Exposure of human skin to solar radiation, which includes ultraviolet (UV) radiation (UVA and UVB) visible light and infrared radiation, induces skin aging. The effects of light have been attributed to irradiation-induced reactive oxygen species (ROS) formation, but the specific signaling pathways are not well understood. Detrimental effects of solar radiation are dermal diseases and photoaging. Exposure of cultured human dermal fibroblasts to UVA, UVB or IRA increased ROS formation in vitro. One important redox regulator is the oxidoreductase thioredoxin-1 (Trx). Trx is ubiquitously expressed and has anti-oxidative and anti-apoptotic properties. Besides its function to reduce H(2)O(2), Trx binds to and regulates transcription factors. The aim of this study was to investigate whether Trx influences the regulation of MMP-1 and collagen Ialpha1 by UVA, UVB and IRA. We irradiated human dermal fibroblasts with UVA, UVB and IRA. UVA, UVB and IRA upregulated MMP-1 expression. Trx inhibited UVA-induced MMP-1 upregulation in a NFkappaB dependent manner. UVA, UVB and IRA reduced collagen Ialpha1 expression. Incubation with Trx inhibited the effects of UVB and IRA on collagen Ialpha1 expression. In conclusion, MMP-1 and collagen Ialpha1, which play important roles in aging processes, seems to be regulated by different transcriptional mechanisms and Trx can only influence distinct signaling pathways induced by UVA, UVB and probably IRA. Thus, Trx may serve as an important contributor to an "anti-aging therapeutic cocktail".

  2. Apoptosis and morphological alterations after UVA irradiation in red blood cells of p53 deficient Japanese medaka (Oryzias latipes).

    PubMed

    Sayed, Alla El-Din Hamid; Watanabe-Asaka, Tomomi; Oda, Shoji; Mitani, Hiroshi

    2016-08-01

    Morphological alterations in red blood cells were described as hematological bioindicators of UVA exposure to investigate the sensitivity to UVA in wild type Japanese medaka (Oryzias latipes) and a p53 deficient mutant. The fewer abnormal red blood cells were observed in the p53 mutant fish under the control conditions. After exposure to different doses of UVA radiation (15min, 30min and 60min/day for 3days), cellular and nuclear alterations in red blood cells were analyzed in the UVA exposed fish compared with non-exposed controls and those alterations included acanthocytes, cell membrane lysis, swollen cells, teardrop-like cell, hemolyzed cells and sickle cells. Those alterations were increased after the UVA exposure both in wild type and the p53 deficient fish. Moreover, apoptosis analyzed by acridine orange assay showed increased number of apoptosis in red blood cells at the higher UVA exposure dose. No micronuclei but nuclear abnormalities as eccentric nucleus, nuclear budding, deformed nucleus, and bilobed nucleus were observed in each group. These results suggested that UVA exposure induced both p53 dependent and independent apoptosis and morphological alterations in red blood cells but less sensitive to UVA than Wild type in medaka fish.

  3. Photosensitized UVA-Induced Cross-Linking between Human DNA Repair and Replication Proteins and DNA Revealed by Proteomic Analysis

    PubMed Central

    2016-01-01

    Long wavelength ultraviolet radiation (UVA, 320–400 nm) interacts with chromophores present in human cells to induce reactive oxygen species (ROS) that damage both DNA and proteins. ROS levels are amplified, and the damaging effects of UVA are exacerbated if the cells are irradiated in the presence of UVA photosensitizers such as 6-thioguanine (6-TG), a strong UVA chromophore that is extensively incorporated into the DNA of dividing cells, or the fluoroquinolone antibiotic ciprofloxacin. Both DNA-embedded 6-TG and ciprofloxacin combine synergistically with UVA to generate high levels of ROS. Importantly, the extensive protein damage induced by these photosensitizer+UVA combinations inhibits DNA repair. DNA is maintained in intimate contact with the proteins that effect its replication, transcription, and repair, and DNA–protein cross-links (DPCs) are a recognized reaction product of ROS. Cross-linking of DNA metabolizing proteins would compromise these processes by introducing physical blocks and by depleting active proteins. We describe a sensitive and statistically rigorous method to analyze DPCs in cultured human cells. Application of this proteomics-based analysis to cells treated with 6-TG+UVA and ciprofloxacin+UVA identified proteins involved in DNA repair, replication, and gene expression among those most vulnerable to cross-linking under oxidative conditions. PMID:27654267

  4. Micronucleated erythrocytes in newborns rats exposed to three different types of ultraviolet-A (UVA) lamps from commonly uses devices.

    PubMed

    Zúñiga-González, Guillermo M; Gómez-Meda, Belinda C; Zamora-Perez, Ana L; Martínez-González, María A; Bautista-Bejarano, Miguel A; Patiño-Valenzuela, Sebastián; Armendáriz-Borunda, Juan; Lazalde-Ramos, Blanca P; Sánchez-Parada, María G; Gallegos-Arreola, Martha P

    2016-12-01

    Exposure to ultraviolet-A (UVA) light can accidentally cause adverse effects in the skin and eyes. UVA induces DNA damage directly by creating pyrimidine dimers or by the formation of reactive oxygen species that can indirectly affect DNA integrity. UVA radiation is emitted by lamps from everyday devices. In adult rats, micronucleated erythrocytes (MNE) are removed from the circulation by the spleen. However, in newborn rats, MNE have been observed in peripheral blood erythrocytes. The objective of this study was to use micronucleus tests to evaluate the DNA damage caused in newborn rats exposed to UVA light from three different types of UVA lamps obtained from commonly used devices: counterfeit detectors, insecticide devices, and equipment used to harden resins for artificial nails. Rat neonates were exposed to UVA lamps for 20min daily for 6days. The neonates were sampled every third day, and the numbers of MNE and micronucleated polychromatic erythrocytes (MNPCE) in the peripheral blood were determined. The rat neonates exposed to the three types of UVA lamps showed increased numbers of MNE and MNPCE from 48h to 144h (P<0.05 and P<0.001 respectively). However, no relationship was observed between the number of MNE and the wattage of the lamps. In conclusion, under these conditions, UVA light exposure induced an increase in MNE without causing any apparent damage to the skin.

  5. Voriconazole N-oxide and its UVB photoproduct sensitize keratinocytes to UVA

    PubMed Central

    Ona-Vu, K.; Oh, D.H.

    2015-01-01

    Background The antifungal agent, voriconazole, is associated with phototoxicity and photocarcinogenicity. Prior work has indicated that voriconazole and its hepatic N-oxide metabolite do not sensitize keratinocytes to ultraviolet B (UVB). Clinical observations have suggested ultraviolet A (UVA) may be involved. Objectives To determine the photochemistry and photobiology of voriconazole and its major hepatic metabolite, voriconazole N-oxide. Methods Voriconazole and voriconazole N-oxide were spectrophotometrically monitored following various doses of UVB. Cultured human keratinocytes were treated with parental drugs or with their UVB photoproducts, and survival following UVA irradiation was measured by thiazolyl blue metabolism. Reactive oxygen species and 8-oxoguanine were monitored by fluorescence microscopy. Results Voriconazole and voriconazole N-oxide have varying ultraviolet B (UVB) absorption but do not acutely sensitize cultured human keratinocytes following UVB exposure. However, sustained UVB exposures produced notable dose- and solvent-dependent changes in the absorption spectra of voriconazole N-oxide which in aqueous solution acquires a prominent ultraviolet A (UVA) absorption band, suggesting formation of a discrete photoproduct. Neither the parental drugs nor their photoproducts sensitized cells to UVB though all but voriconazole N-oxide were moderately toxic to cells in the dark. Notably, both voriconazole N-oxide and its UVB photoproduct, but not voriconazole or its photoproduct, additionally sensitized cells to UVA by >3-fold relative to controls in association with UVA-induced reactive oxygen species and 8-oxoguanine levels. Conclusions Voriconazole N-oxide and its UVB-photoproduct act as UVA-sensitizers that generate reactive oxygen species and that produce oxidative DNA damage. These results suggest a mechanism for the phototoxicity and photocarcinogenicity observed with voriconazole treatment. PMID:25919127

  6. Measurements of UV-A radiation and hazard limits from some types of outdoor lamps

    NASA Astrophysics Data System (ADS)

    El-Moghazy, Essam; Abd-Elmageed, Alaa-Eldin; Reda, Sameh

    2015-05-01

    Illumination using artificial light sources is common in these days. Many manufactures are paying for the design of lamps depending on high efficacy and low UV hazards. This research is focusing on the most useable lamps in the Egyptian markets; High Pressure Mercury (HPM), Metal Halide (MH), and High Pressure Sodium (HPS). A set up for relative spectral power distribution based on single monochromator and UVA silicon detector for absolute irradiance measurements are used. The absolute irradiance in (W/m2) in UVA region of the lamps and their accompanied standard uncertainty are evaluated.

  7. Pilot Study for UVA-LED Disinfection of Escherichia coli in Water for Space and Earth Applications

    NASA Technical Reports Server (NTRS)

    Ragolta, Carolina

    2010-01-01

    To test the efficacy of UVA-LED disinfection, a solution of Escherichia coli was pumped through a modified drip flow reactor at a flow rate of 1 ml/min. The experiment was conducted in a controlled environment chamber to ensure that temperature did not cause disinfection. The reactor featured three wells with different treatments: UVA-LED irradiation, UVA-LEDs with Ti02, and UVA-LEDs with nanosilver. Samples from each well were taken throughout a 340 hour period, inactivated, assayed, and analyzed for E. coli disinfection. Results of the duplicate experiments indicated longer exposure times are needed for UVA-LED disinfection of E. coli in water. Further research would consider a longer sampling period and different test conditions, such as increased contact area and various flow rates.

  8. Possible involvement of ERK 1/2 in UVA-induced melanogenesis in cultured normal human epidermal melanocytes.

    PubMed

    Yanase, H; Ando, H; Horikawa, M; Watanabe, M; Mori, T; Matsuda, N

    2001-04-01

    UV-induced melanogenesis is a well known physiological response of human skin exposed to solar radiation; however, the signaling molecules involved in the stimulation of melanogenesis in melanocytes following UV exposure remain unclear. In this study we induced melanogenesis in vitro in normal human epidermal melanocytes using a single irradiation with UVA at 1 kJ/m2 and examined the potential involvement of mitogen-activated protein kinases (MAPK) as UVA-responsive signaling molecules in those cells. UVA irradiation did not affect the proliferation of melanocytes, but it did increase tyrosinase mRNA expression, which reached a maximum level 4 hr after UVA irradiation. The amount of tyrosinase protein, as quantitated by immunoblotting, was also increased at 24 hr following UVA irradiation. Among the MAPK examined, extracellular signal-related kinase (ERK) 1/2 was phosphorylated within 15 min of UVA irradiation, but no such phosphorylation was observed for c-Jun N-terminal kinases (JNK) or p38. Accordingly, the activity of ERK1/2 was also increased shortly after UVA irradiation. These responses of ERK1/2 to UVA irradiation were markedly inhibited when cells were pre-treated with N-acetyl-L-cysteine, an antioxidant, or with suramin, a tyrosine kinase receptor inhibitor. The formation of (6-4)photoproducts or cyclobutane pyrimidine dimers was not detected in cellular DNA after UVA irradiation. These findings suggest that a single UVA irradiation-induced melanogenesis is associated with the activation of ERK1/2 by upstream signals that originate from reactive oxygen species or from activated tyrosine kinase receptors, but not from damaged DNA.

  9. In vivo UVA irradiation of mouse is more efficient in promoting pulmonary melanoma metastasis than in vitro

    PubMed Central

    2011-01-01

    Background We have previously shown in vitro that UVA increases the adhesiveness of mouse B16-F1 melanoma cells to endothelium. We have also shown in vivo that UVA exposure of C57BL/6 mice, i.v. injected with B16-F1 cells, increases formation of pulmonary colonies of melanoma. The aim of the present animal study was to confirm the previously observed in vivo UVA effect and to determine whether in vitro UVA-exposure of melanoma cells, prior the i.v. injection, will have an enhancing effect on the pulmonary colonization capacity of melanoma cells. As a second aim, UVA-derived immunosuppression was determined. Methods Mice were i.v. injected with B16-F1 cells into the tail vein and then immediately exposed to UVA. Alternatively, to study the effect of UVA-induced adhesiveness on the colonization capacity of B16-F1 melanoma, cells were in vitro exposed prior to i.v. injection. Fourteen days after injection, lungs were collected and the number of pulmonary nodules was determined under dissecting microscope. The UVA-derived immunosuppression was measured by standard contact hypersensitivity assay. Results and Discussion Obtained results have confirmed that mice, i.v. injected with B16-F1 cells and thereafter exposed to UVA, developed 4-times more of melanoma colonies in lungs as compared with the UVA non-exposed group (p < 0.01). The in vitro exposure of melanoma cells prior to their injection into mice, led only to induction of 1.5-times more of pulmonary tumor nodules, being however a statistically non-significant change. The obtained results postulate that the UVA-induced changes in the adhesive properties of melanoma cells do not alone account for the 4-fold increase in the pulmonary tumor formation. Instead, it suggests that some systemic effect in a mouse might be responsible for the increased metastasis formation. Indeed, UVA was found to induce moderate systemic immunosuppression, which effect might contribute to the UVA-induced melanoma metastasis in mice lungs

  10. Dynamic characterization and microprocessor control of the NASA/UVA proof mass actuator

    NASA Technical Reports Server (NTRS)

    Zimmerman, D. C.; Inman, D. J.; Horner, G. C.

    1984-01-01

    The self-contained electromagnetic-reaction-type force-actuator system developed by NASA/UVA for the verification of spacecraft-structure vibration-control laws is characterized and demonstrated. The device is controlled by a dedicated microprocessor and has dynamic characteristics determined by Fourier analysis. Test data on a cantilevered beam are shown.

  11. Alternate trafficking of cathepsin L in dermal fibroblasts induced by UVA radiation.

    PubMed

    Klose, Anke; Wilbrand-Hennes, Astrid; Brinckmann, Jürgen; Hunzelmann, Nicolas

    2010-08-01

    UVA radiation is increasingly used to treat fibrotic skin disorders. However, the mechanisms underlying the therapeutic effects of UVA for these disorders are only partially understood. Cathepsin L is a lysosomal cysteine protease, which has been shown to degrade various matrix proteins thus contributing to extracellular remodeling. Therefore, we investigated whether UVA irradiation regulates the expression and release of cathepsin L in human dermal fibroblasts. No alterations were found after single irradiation; however, a significantly increased extracellular release of cathepsin L was observed after repeated irradiation up to four times. The transcript levels of cathepsin L were elevated after repetitive irradiation, leading to increased amounts of total cathepsin L protein. Furthermore, higher amounts of extracellular cathepsin L were associated with a significant reduction of intracellular processed cathepsin L and an accumulation of unprocessed procathepsin L. The use of specific inhibitors elucidated mannose phosphate-independent sorting pathways of cathepsin L leading to enhanced secretion and reduced intracellular processing. This is the first study which demonstrates that alternate trafficking mechanisms mediate the extracellular release of a cysteine protease induced by repetitive UVA irradiation.

  12. Photoprotective Effects of Cycloheterophyllin against UVA-Induced Damage and Oxidative Stress in Human Dermal Fibroblasts.

    PubMed

    Huang, Cheng-Hua; Li, Hsin-Ju; Wu, Nan-Lin; Hsiao, Chien-Yu; Lin, Chun-Nan; Chang, Hsun-Hsien; Hung, Chi-Feng

    2016-01-01

    Ultraviolet (UV) radiation, particularly ultraviolet A (UVA), is known to play a major role in photoaging of the human skin. Many studies have demonstrated that UV exposure causes the skin cells to generate reactive oxygen species and activates the mitogen-activated protein kinase (MAPK) pathway. Previous studies have also demonstrated that cycloheterophyllin has an antioxidant effect and can effectively scavenge free radicals. Extending the aforementioned investigations, in this study, human dermal fibroblasts were used to investigate the protective effect of cycloheterophyllin against UV-induced damage. We found that cycloheterophyllin not only significantly increased cell viability, but also attenuated the phosphorylation of MAPK after UVA exposure. Furthermore, cycloheterophyllin could reduce hydrogen peroxide (H2O2) generation and down-regulate H2O2-induced MAPK phosphorylation. In the in vivo studies, the topical application of cycloheterophyllin before UVA irradiation significantly decreased trans-epidermal water loss (TEWL), erythema, and blood flow rate. These results indicate that cycloheterophyllin is a photoprotective agent that inhibits UVA-induced oxidative stress and damage, and could be used in the research on and prevention of skin photoaging.

  13. Why soft UV-A damages DNA: An optical micromanipulation study

    NASA Astrophysics Data System (ADS)

    Rapp, A.; Greulich, K. O.

    2013-09-01

    Optical micromanipulation studies have solved a puzzle on DNA damage and repair. Such knowledge is crucial for understanding cancer and ageing. So far it was not understood, why the soft UV component of sunlight, UV-A, causes the dangerous DNA double strand breaks. The energy of UV-A photons is below 4 eV per photon, too low to directly cleave the corresponding chemical bonds in DNA. This is occasionally used to claim that artificial sunbeds, which mainly use UV-A, would not impose a risk on health. UV-A is only sufficient for induction of single strand breaks. The essential new observation is that, when on the opposite strand there is another single strand break at a distance of up to 20 base pairs. These two breaks will be converted into a break of the whole double strand with all its known consequences for cancer and ageing. However, in natural sun the effect is counteracted. Simultaneous red light illumination reduces UV induced DNA damages to 1/3. Since sunlight has a red component, skin tanning with natural sun is not as risky as might appear at a first glance.

  14. Photoprotective Effects of Cycloheterophyllin against UVA-Induced Damage and Oxidative Stress in Human Dermal Fibroblasts

    PubMed Central

    Huang, Cheng-Hua; Li, Hsin-Ju; Wu, Nan-Lin; Hsiao, Chien-Yu; Lin, Chun-Nan; Chang, Hsun-Hsien; Hung, Chi-Feng

    2016-01-01

    Ultraviolet (UV) radiation, particularly ultraviolet A (UVA), is known to play a major role in photoaging of the human skin. Many studies have demonstrated that UV exposure causes the skin cells to generate reactive oxygen species and activates the mitogen-activated protein kinase (MAPK) pathway. Previous studies have also demonstrated that cycloheterophyllin has an antioxidant effect and can effectively scavenge free radicals. Extending the aforementioned investigations, in this study, human dermal fibroblasts were used to investigate the protective effect of cycloheterophyllin against UV-induced damage. We found that cycloheterophyllin not only significantly increased cell viability, but also attenuated the phosphorylation of MAPK after UVA exposure. Furthermore, cycloheterophyllin could reduce hydrogen peroxide (H2O2) generation and down-regulate H2O2-induced MAPK phosphorylation. In the in vivo studies, the topical application of cycloheterophyllin before UVA irradiation significantly decreased trans-epidermal water loss (TEWL), erythema, and blood flow rate. These results indicate that cycloheterophyllin is a photoprotective agent that inhibits UVA-induced oxidative stress and damage, and could be used in the research on and prevention of skin photoaging. PMID:27583973

  15. Functional photostability and cutaneous compatibility of bioactive UVA sun care products.

    PubMed

    de Oliveira, Camila Areias; Peres, Daniela D'Almeida; Rugno, Caynan Mendes; Kojima, Mayara; Pinto, Claudinéia Aparecida Sales de Oliveira; Consiglieri, Vladi Olga; Kaneko, Telma Mary; Rosado, Catarina; Mota, Joana; Velasco, Maria Valéria Robles; Baby, André Rolim

    2015-07-01

    Sunscreens are the most-established approach for photoprotection. The strategy of providing antioxidant properties to sun care products by addition of natural and potent anti-free radical compounds has led to the development of bioactive sunscreens, able to neutralize the harmful effects of ultraviolet (UV) radiation. UVA filters, such as benzophenone-3 (BP) and butyl methoxydibenzoylmethane (BMDBM), can exhibit photodegradation which limits the development of broad spectrum sunscreens. Previous research verified that rutin interacts with filters incorporated in sunscreens. In this work, we focused on the development and evaluation of the efficacy of the sunscreens containing either BP or BMDBM with and without rutin. The addition of rutin to the UVA filters afforded antioxidant properties to the formulations and they were considered safe for human use. Additionally, rutin in combination with either BP or BMDBM increased the antioxidant activity about 40 times when compared with the UVA filters alone. Remarkably, the addition of rutin 0.1% (w/w) to BP 6.0% (w/w) raised the SPF from 24.3±1.53 to 33.3±2.89. In conclusion, these findings demonstrated that the addition of rutin into sunscreens can markedly improve the antioxidant properties of the formulation as well as photostabilize some of the UVA filters.

  16. Plant responses to UV-B irradiation are modified by UV-A irradiation

    SciTech Connect

    Middleton, E.M.; Teramura, A.H. Univ. of Maryland, College Park )

    1993-06-01

    The increasing UV-B radiation (0.28-0.32 [mu]m) reaching the earth's surface is an important concern. Plant response in artificial UV-B irradiation studies has been difficult to assess, especially regarding photosynthetic pigments, because the fluorescent lamps also produce UV-A (0.32-0.40[mu]m) radiation which is involved with blue light in pigment synthesis. Both UV-A and UV-B irradiances were controlled in two glasshouse experiments conducted under relatively high PPFD (> 1300[mu]mol m[sup [minus]2] s[sup [minus]1]) at two biologically effective daily UV-B irradiances (10.7 and 14.1 kJ m[sup [minus]2]); UV-A irradiances were matched in Controls ([approximately]5, 9 kJ m[sup [minus]2]). Normal, chlorophyll-deficient, and flavonoid-deficient isolines of soybean cultivar, Clark, were utilized. Many growth/ pigment variables exhibited a statistically significant interaction between light quality and quantity: in general, UV-A radiation moderated the damaging effects of UV-B radiation. Regression analyses demonstrated that a single negative function related photosynthetic efficiency to carotenoid Content (r[sup 2] =0.73, P[le]0.001), implying a [open quotes]cost[close quotes] in maintaining carotenoids for photoprotection. A stomatal limitation to photosynthesis was verified and carotenoid content was correlated with UV-B absorbing compound levels, in UV-B irradiated plants.

  17. Molecular modifications of dermal and epidermal biomarkers following UVA exposures on reconstructed full-thickness human skin.

    PubMed

    Meloni, Marisa; Farina, Anne; de Servi, Barbara

    2010-04-01

    Ultraviolet A (UVA) radiation adversely affects skin health and appearance via multiple molecular pathways. Biologically relevant UVA damage are classified as short-term effects (e.g. formation of reactive oxygen species [ROS], inflammation, photo-oxidation, DNA damage, immunosuppression, photoallergy and cell-mediated contact hypersensitivity) or long-term effects (elastosis, photoageing and photocarcinogenesis). Single and chronic experimental exposure to UVA are limited in humans by ethical concerns, and furthermore it is impossible to quantify long-term endpoints such as photoageing over the life-span of a human volunteer. The aim of the present study was to investigate the biological relevance of the Phenion FT skin model for use in photobiological studies. Biological responses to acute and repeated UVA exposures were investigated by monitoring the kinetics of gene expression during the post-irradiation period. By using a dynamic approach, we were able to define early and stable markers of UVA-induced effects that could be predictive of UVA damage in vivo. The transcriptomic approach applied to 3D human tissues appears to be an encouraging method for gaining a deeper understanding of the UVA effects on skin and for studying the dermal response with non-invasive techniques.

  18. NF-E2-related factor 2 regulates the stress response to UVA-1-oxidized phospholipids in skin cells.

    PubMed

    Gruber, Florian; Mayer, Herbert; Lengauer, Barbara; Mlitz, Veronika; Sanders, John M; Kadl, Alexandra; Bilban, Martin; de Martin, Rainer; Wagner, Oswald; Kensler, Thomas W; Yamamoto, Masayuki; Leitinger, Norbert; Tschachler, Erwin

    2010-01-01

    Long-wavelength ultraviolet (UVA-1) radiation causes oxidative stress that modifies cellular molecules. To defend themselves against noxious oxidation products, skin cells produce detoxifying enzymes and antioxidants. We have recently shown that UVA-1 oxidized the abundant membrane phospholipid 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphorylcholine (PAPC), which then induced the stress-response protein heme oxygenase 1 (HO-1) in dermal fibroblasts. Here we examined the effects of UVA-1- and UV-oxidized phospholipids on global gene expression in human dermal fibroblasts and keratinocytes. We identified a cluster of genes that were coinduced by UVA-1-oxidized PAPC and UVA-1 radiation. The cluster included HO-1, glutamate-cysteine ligase modifier subunit, aldo-keto reductases-1-C1 and -C2, and IL-8. These genes are members of the cellular stress response system termed "antioxidant response." Accordingly, the regulatory regions of all of these genes contain binding sites for NF-E2-related factor 2 (NRF2), a major regulator of the antioxidant response. Both UVA-1 irradiation and treatment with oxidized lipids led to increased nuclear accumulation and DNA binding of NRF2. Silencing and deficiency of NRF2 suppressed the antioxidant response. Taken together, our data show that UVA-1-mediated lipid oxidation induces expression of antioxidant response genes, which is dependent on the redox-regulated transcription factor NRF2. Our findings suggest a different view on UV-generated lipid mediators that were commonly regarded as detrimental

  19. Propolis Inhibits UVA-Induced Apoptosis of Human Keratinocyte HaCaT Cells by Scavenging ROS

    PubMed Central

    Kim, Han Bit; Yoo, Byung Sun

    2016-01-01

    Propolis is a resinous material collected by honeybees from several plant sources. This research aimed at showing its protective effect against UVA-induced apoptosis of human keratinocyte HaCaT cells. Using Hoechst staining, it was demonstrated that propolis (5 and 10 μg/mL) significantly inhibited the apoptosis of HaCaT cells induced by UVA-irradiation. Propolis also showed the protective effect against loss of mitochondrial membrane potential induced by UVA-irradiaiton in HaCaT cells. Propolis also inhibited the expression of activated caspase-3 induced by UVA-irradiation. To investigate the role of ROS in UVA-induced apoptosis and protection by propolis, the generation of ROS was determined in cells. The results showed that the generation of ROS was markedly reduced in cells pretreated with propolis. Consequently, propolis protected human keratinocyte HaCaT cells against UVA-induced apoptosis, which might be related to the reduction of ROS generation by UVA-irradiation. PMID:27818737

  20. Effects of short time UV-A exposures on compound eyes and haematological parameters in Procambarus clarkii (Girad, 1852).

    PubMed

    El-Bakary, Zeinab A; Sayed, Alaa El-Din H

    2011-05-01

    The amount of ultraviolet radiation (UVR) reaching the Earth's surface has been increasing as a result of an increasingly thinner ozone layer. The UV-A component of the UVR is able to generate oxidative stress in the compound eye and haemolymph of Procambarus clarkii when the latter was exposed for as little as 15 min daily for one week to UV-A. Changes in the eye involved corneal material, crystalline cones, pigments in cone stalks and retinula cells, rhabdom integrity, haemocyte infiltration, and haemal spaces. UV-A had significant impacts on haemolymph iron and glucose, whereas Ca ions were unaffected. Total protein and Cu-ions showed only insignificant changes following UV-A radiation. Involvement of lipid peroxidation and DNA fragmentation was significant with regard to the tissue damage cause by the UV-A. UV-A furthermore induced biological effects on serum electrophoretic patterns: some fractions either increased in size or others decreased. The described changes can be used as reference guidelines in evaluations of UV-A induced stress effects in P. clarkii.

  1. Influence of uvA on the erythematogenic and therapeutic effects of uvB irradiation in psoriasis; photoaugmentation effects

    SciTech Connect

    Boer, J.; Schothorst, A.A.; Suurmond, D.

    1981-01-01

    The effect of repeated exposure to an additive dose of long ultraviolet (uvA) radiation on the erythemogenic and therapeutic effects of middle ultraviolet (uvB) irradiation was investigated in 8 patients with psoriasis. The surface of the backs of these patients was divided into 2 parts, 1 of which received only uvB irradiation 4 times a week and the other uvA + uvB. uvB was provided by Philips TL-12 lamps and uvA by glass-filtered Philips TL-09 lamps. uvA was held constantly at 10 J/cm2, whereas uvB alone were evaluated by 4 tests during the treatment to determine the minimal erythema dose (MED). Test I (at the start of the therapy) showed a photoaugmentative effect which was no longer apparent in Test III (third week). Test III showed a reversal of the ratios of the MEDs of the sites irradiated with the uvA + uvB and uvB (MED A + B/MED B). This is ascribed to the marked pigmentation which appeared after repeated irradiation with the uvA + uvB combination. Comparison showed for the improvement of the psoriasis no distinct differences between uvA + uvB irradiation and uvB alone, but the former had the cosmetic advantage of giving pleasing tan.

  2. Effect of supplemental UV-A irradiation in solid-state lighting on the growth and phytochemical content of microgreens

    NASA Astrophysics Data System (ADS)

    Brazaitytė, A.; Viršilė, A.; Jankauskienė, J.; Sakalauskienė, S.; Samuolienė, G.; Sirtautas, R.; Novičkovas, A.; Dabašinskas, L.; Miliauskienė, J.; Vaštakaitė, V.; Bagdonavičienė, A.; Duchovskis, P.

    2015-01-01

    In this study, we sought to find and employ positive effects of UV-A irradiation on cultivation and quality of microgreens. Therefore, the goal of our study was to investigate the influence of 366, 390, and 402 nm UV-A LED wavelengths, supplemental for the basal solid-state lighting system at two UV-A irradiation levels on the growth and phytochemical contents of different microgreen plants. Depending on the species, supplemental UV-A irradiation can improve antioxidant properties of microgreens. In many cases, a significant increase in the investigated phytochemicals was found under 366 and 390 nm UV-A wavelengths at the photon flux density (12.4 μmol m-2 s-1). The most pronounced effect of supplemental UV-A irradiation was detected in pak choi microgreens. Almost all supplemental UV-A irradiation treatments resulted in increased leaf area and fresh weight, in higher 2,2-diphenyl-1-picrylhydrazyl free-radical scavenging activity, total phenols, anthocyanins, ascorbic acid, and α-tocopherol.

  3. UVA-induced DNA double-strand breaks result from the repair of clustered oxidative DNA damages

    PubMed Central

    Greinert, R.; Volkmer, B.; Henning, S.; Breitbart, E. W.; Greulich, K. O.; Cardoso, M. C.; Rapp, Alexander

    2012-01-01

    UVA (320–400 nm) represents the main spectral component of solar UV radiation, induces pre-mutagenic DNA lesions and is classified as Class I carcinogen. Recently, discussion arose whether UVA induces DNA double-strand breaks (dsbs). Only few reports link the induction of dsbs to UVA exposure and the underlying mechanisms are poorly understood. Using the Comet-assay and γH2AX as markers for dsb formation, we demonstrate the dose-dependent dsb induction by UVA in G1-synchronized human keratinocytes (HaCaT) and primary human skin fibroblasts. The number of γH2AX foci increases when a UVA dose is applied in fractions (split dose), with a 2-h recovery period between fractions. The presence of the anti-oxidant Naringin reduces dsb formation significantly. Using an FPG-modified Comet-assay as well as warm and cold repair incubation, we show that dsbs arise partially during repair of bi-stranded, oxidative, clustered DNA lesions. We also demonstrate that on stretched chromatin fibres, 8-oxo-G and abasic sites occur in clusters. This suggests a replication-independent formation of UVA-induced dsbs through clustered single-strand breaks via locally generated reactive oxygen species. Since UVA is the main component of solar UV exposure and is used for artificial UV exposure, our results shine new light on the aetiology of skin cancer. PMID:22941639

  4. Application of UVA-riboflavin crosslinking to enhance the mechanical properties of extracellular matrix derived hydrogels.

    PubMed

    Ahearne, Mark; Coyle, Aron

    2016-02-01

    Hydrogels derived from extracellular matrix (ECM) have become increasing popular in recent years, particularly for use in tissue engineering. One limitation with ECM hydrogels is that they tend to have poor mechanical properties compared to native tissues they are trying to replicate. To address this problem, a UVA (ultraviolet-A) riboflavin crosslinking technique was applied to ECM hydrogels to determine if it could be used to improve their elastic modulus. Hydrogels fabricated from corneal, cardiac and liver ECM were used in this study. The mechanical properties of the hydrogels were characterized using a spherical indentation technique. The microstructure of the hydrogels and the cytotoxic effect of crosslinking on cell seeded hydrogels were also evaluated. The combination of UVA light and riboflavin solution led to a significant increase in elastic modulus from 6.8kPa to 24.7kPa, 1.4kPa to 6.9kPa and 0.9kPa to 1.6kPa for corneal, cardiac and liver ECM hydrogels respectively. The extent of this increase was dependent on a number of factors including the UVA exposure time and the initial hydrogel concentration. There were also a high percentage of viable cells within the cell seeded hydrogels with 94% of cells remaining viable after 90min exposure to UVA light. These results suggest that UVA-riboflavin crosslinking is an effective approach for improving the mechanical properties of ECM hydrogels without resulting in a significant reduction of cell viability.

  5. Direct participation of DNA in the formation of singlet oxygen and base damage under UVA irradiation.

    PubMed

    Yagura, Teiti; Schuch, André Passaglia; Garcia, Camila Carrião Machado; Rocha, Clarissa Ribeiro Reily; Moreno, Natália Cestari; Angeli, José Pedro Friedmann; Mendes, Davi; Severino, Divinomar; Bianchini Sanchez, Angelica; Di Mascio, Paolo; de Medeiros, Marisa Helena Gennari; Menck, Carlos Frederico Martins

    2017-03-18

    UVA light is hardly absorbed by the DNA molecule, but recent works point to a direct mechanism of DNA lesion by these wavelengths. UVA light also excite endogenous chromophores, which causes DNA damage through ROS. In this study, DNA samples were irradiated with UVA light in different conditions to investigate possible mechanisms involved in the induction of DNA damage. The different types of DNA lesions formed after irradiation were determined through the use of endonucleases, which recognize and cleave sites containing oxidized bases and cyclobutane pyrimidine dimers (CPDs), as well as through antibody recognition. The formation of 8-oxo-7,8-dihydro-2'-deoxyguanine (8-oxodG) was also studied in more detail using electrochemical detection. The results show that high NaCl concentration and concentrated DNA are capable of reducing the induction of CPDs. Moreover, concerning damage caused by oxidative stress, the presence of sodium azide and metal chelators reduce their induction, while deuterated water increases the amounts of oxidized bases, confirming the involvement of singlet oxygen in the generation of these lesions. Curiously, however, high concentrations of DNA also enhanced the formation of oxidized bases, in a reaction that paralleled the increase in the formation of singlet oxygen in the solution. This was interpreted as being due to an intrinsic photosensitization mechanism, depending directly on the DNA molecule to absorb UVA and generate singlet oxygen. Therefore, the DNA molecule itself may act as a chromophore for UVA light, locally producing a damaging agent, which may lead to even greater concerns about the deleterious impact of sunlight.

  6. Effect of surface modification and UVA photoactivation on antibacterial bioactivity of zinc oxide powder

    NASA Astrophysics Data System (ADS)

    Ann, Ling Chuo; Mahmud, Shahrom; Bakhori, Siti Khadijah Mohd; Sirelkhatim, Amna; Mohamad, Dasmawati; Hasan, Habsah; Seeni, Azman; Rahman, Rosliza Abdul

    2014-02-01

    The effects of surface modification of zinc oxide (ZnO) powder and UVA illumination on the powder towards Escherichia coli and Staphylococcus aureus were investigated. FESEM-EDS results showed that oxygen annealing increased the O:Zn ratio on the surface of ZnO-rod and ZnO-plate samples. Surface conductances of ZnO-rod and ZnO-plate pellets were reduced from 1.05 nS to 0.15 nS and 1.34 nS to 0.23 nS, respectively. Meanwhile, UVA illumination on the surface of the ZnO-rod and ZnO-plate samples was found to improve surface conductance to 7.08 nS and 6.51 nS, respectively, due to the release of charge carrier. Photoluminescence results revealed that oxygen annealing halved the UV emission intensity and green emission intensity, presumably caused by oxygen absorption in the ZnO lattice. The antibacterial results showed that oxygen-treated ZnO exhibited slightly higher growth inhibition on E. coli and S. aureus compared with unannealed ZnO. UVA illumination on ZnO causes the greatest inhibition toward E. coli and S. aureus. Under the UVA excitation, the inhibition of E. coli increased by 18% (ZnO-rod) and 13% (ZnO-plate) while the inhibition of S. aureus increased by 22% (ZnO-rod) and 21% (ZnO-plate). Release of reactive oxygen species were proposed in antibacterial mechanisms, which were aided by surface modification and UVA photoactivation. The reactive oxygen species disrupted the DNA and protein synthesis of the bacterial cell, causing bacteriostatic effects toward E. coli and S. aureus.

  7. Disinfection of Spacecraft Potable Water Systems by Photocatalytic Oxidation Using UV-A Light Emitting Diodes

    NASA Technical Reports Server (NTRS)

    Birmele, Michele N.; O'Neal, Jeremy A.; Roberts, Michael S.

    2011-01-01

    Ultraviolet (UV) light has long been used in terrestrial water treatment systems for photodisinfection and the removal of organic compounds by several processes including photoadsorption, photolysis, and photocatalytic oxidation/reduction. Despite its effectiveness for water treatment, UV has not been explored for spacecraft applications because of concerns about the safety and reliability of mercury-containing UV lamps. However, recent advances in ultraviolet light emitting diodes (UV LEDs) have enabled the utilization of nanomaterials that possess the appropriate optical properties for the manufacture of LEDs capable of producing monochromatic light at germicidal wavelengths. This report describes the testing of a commercial-off-the-shelf, high power Nichia UV-A LED (250mW A365nnJ for the excitation of titanium dioxide as a point-of-use (POD) disinfection device in a potable water system. The combination of an immobilized, high surface area photocatalyst with a UV-A LED is promising for potable water system disinfection since toxic chemicals and resupply requirements are reduced. No additional consumables like chemical biocides, absorption columns, or filters are required to disinfect and/or remove potentially toxic disinfectants from the potable water prior to use. Experiments were conducted in a static test stand consisting of a polypropylene microtiter plate containing 3mm glass balls coated with titanium dioxide. Wells filled with water were exposed to ultraviolet light from an actively-cooled UV-A LED positioned above each well and inoculated with six individual challenge microorganisms recovered from the International Space Station (ISS): Burkholderia cepacia, Cupriavidus metallidurans, Methylobacterium fujisawaense, Pseudomonas aeruginosa, Sphingomonas paucimobilis and Wautersia basilensis. Exposure to the Nichia UV-A LED with photocatalytic oxidation resulted in a complete (>7-log) reduction of each challenge bacteria population in <180 minutes of contact

  8. An experimental and theoretical model for solar UVA-irradiation of soluble eumelanin: towards modelling UVA-photoreactions in the melanosome?

    PubMed

    Haywood, Rachel M; Linge, Claire

    2004-10-25

    A model is developed for the UVA-irradiation of soluble eumelanin exposed to levels of irradiation comparable to sunlight. Radical production was determined in soluble dl- and l-dopa melanins exposed to solar levels of UVA, using electron spin resonance spectroscopy and the spin trap 5,5-dimethyl-1-pyrroline N-oxide (DMPO). Steady-state concentrations of DMPO-O(2)H(.-), which increased up to 0.3 mg/ml melanin, and then declined above 0.3 mg/ml, were detected at pH 4.5. The kinetic model incorporated the photosensitizing and radical-scavenging reactions of eumelanin, and assumed semiquinone radical reduction of oxygen to be fast compared to disproportionation. The model is consistent with experimental data for melanin concentrations <0.1 mg/ml; but >0.1 mg/ml melanin is consistent only with data at raised oxygen tension. The rate-constant for reaction of the melanin semiquinone-radical and oxygen is estimated to be 10(3) mol(-1)dm(3)s(-1). In this model, where DMPO competes with melanin for HO(2)(.-), at ambient oxygen levels, eumelanin exposed to solar levels of UVA photosensitizes superoxide at concentrations <0.3 mg/ml melanin, and is increasingly stable towards oxidation when >0.3 mg/ml concentration. Eumelanin could have a negligible screening effect <0.1 mg/ml and very strong screening >1 mg/ml. This model would be biologically relevant if soluble forms of eumelanin were shown to exist in vivo, and is potentially useful for studies of the photochemistry and photophysics of eumelanin and phaeomelanin and to explore the effects of metal-ions, proteins and lipids in a model system.

  9. Skin Treatment with Pulsed Monochromatic UVA1 355 Device and Computerized Morphometric Analysis of Histochemically Identified Langerhans Cells

    PubMed Central

    Zerbinati, Nicola; Riva, Federica; Paulli, Marco; Parodi, Pier Camillo

    2016-01-01

    Fluorescent or metal halide lamps are widely used in therapeutic applications in dermatological diseases, with broadband or narrow band emission UVA/UVA1 (320–400 nm) obtained with suitable passive filters. Recently, it has been possible for us to use a new machine provided with solid state source emitting pulsed monochromatic UVA1 355 nm. In order to evaluate the effects of this emission on immunocells of the skin, human skin samples were irradiated with monochromatic 355 nm UVA1 with different energetic fluences and after irradiation Langerhans cells were labeled with CD1a antibodies. The immunohistochemical identification of these cells permitted evaluating their modifications in terms of density into the skin. Obtained results are promising for therapeutical applications, also considering that a monochromatic radiation minimizes thermic load and DNA damage in the skin tissues. PMID:27525266

  10. Ultrasonic vibration-assisted (UV-A) pelleting of wheat straw: a constitutive model for pellet density.

    PubMed

    Song, Xiaoxu; Zhang, Meng; Pei, Z J; Wang, Donghai

    2015-07-01

    Ultrasonic vibration-assisted (UV-A) pelleting can increase cellulosic biomass density and reduce biomass handling and transportation costs in cellulosic biofuel manufacturing. Effects of input variables on pellet density in UV-A pelleting have been studied experimentally. However, there are no reports on modeling of pellet density in UV-A pelleting. Furthermore, in the literature, most reported density models in other pelleting methods of biomass are empirical. This paper presents a constitutive model to predict pellet density in UV-A pelleting. With the predictive model, relations between input variables (ultrasonic power and pelleting pressure) and pellet density are predicted. The predicted relations are compared with those determined experimentally in the literature. Model predictions agree well with reported experimental results.

  11. Changes in ultraviolet absorbance and hence in protective efficacy against lipid peroxidation of organic sunscreens after UVA irradiation.

    PubMed

    Damiani, Elisabetta; Rosati, Luca; Castagna, Riccardo; Carloni, Patricia; Greci, Lucedio

    2006-03-01

    Owing to the spectral distribution of solar UV, the UVA component of sunlight is now believed to be the main cause of photoaging and photocarcinogenesis and is much more effective than UVB in inducing peroxidative damage. Consequently, most skin care cosmetic products now include UVA filters in their formulations along with UVB filters. These modern sunscreens should provide and maintain their initial absorbance, hence protection, throughout the entire period of exposure to sunlight. However, not all UVA and UVB filters are sufficiently photostable. In this study, we examine the correlation between the photochemical degradation of sunscreen agents under UVA irradiation, with particular reference to the UVA-absorber 4-tert-butyl-4'-methoxydibenzoylmethane, alone and in combination with other organic UV filters (2-ethylhexyl 4 methoxycinnamate and 2-ethylhexyl 2-cyano-3,3-diphenylacrylate) and their ability to prevent UVA-induced lipid peroxidation. Since antioxidants are also added to formulations to deactivate free radicals generated during UVA exposure, vitamin E and the synthetic antioxidant, bis(2,2,6,6-tetramethyl-1-oxyl-piperidine-4-yl)sebacate, a nitroxide derivative, were also included in this study. By using simple in vitro tests, the results show that a decrease in spectral absorbance of the UV filters correlates in most cases with increased UVA-induced lipid peroxidation; this depends on the specific UV absorber analysed and also on whether they are alone or in combination. Furthermore, the combined presence or absence of antioxidants has a profound effect on this oxidative event. In particular, the nitroxide appears to be a more efficient photo-antioxidant than vitamin E. Similar experiments were also performed under natural sunlight and the results obtained did not differ substantially from those performed under UVA. The results presented and discussed in this work may help in understanding the effects of UVA/UVB absorbers and antioxidants upon the

  12. Long-term risks of psoralen and UV-A therapy for psoriasis

    SciTech Connect

    Farber, E.M.; Abel, E.A.; Cox, A.J.

    1983-05-01

    It has been more than eight years since photochemotherapy with methoxsalen and UV-A (psoralen and UV-A (PUVA)) was introduced for the treatment of psoriasis. This treatment remained under investigation until May 1982 because of concerns about possible chronic toxic effects. With recent Food and Drug Administration approval of PUVA therapy for severe psoriasis, strict drug labeling for administration and patient use and continued monitoring of side effects have become essential. The full effects of PUVA in regard to carcinogenicity, prematurelly induced aging of the skin, pigmentary changes, immunologic alterations, and ocular side effects are still unknown. A review of the risks of PUVA therapy is presented, with the aim of maintaining a proper perspective for its limited use in treating selected patients.

  13. Effects of supplemental UV-A on the development, anatomy and metabolite production of Phyllanthus tenellus cultured in vitro.

    PubMed

    Victório, Cristiane Pimentel; Leal-Costa, Marcos Vinicius; Tavares, Eliana Schwartz; Kuster, Ricardo Machado; Lage, Celso Luiz Salgueiro

    2011-01-01

    Phyllanthus tenellus is widely used for its antiviral, analgesic and hepatoprotective properties. Although the production of several chemical classes of secondary metabolites is influenced by UV radiation, particularly phenolic compounds, we also know that UV radiation can result in anatomical and developmental damage. However, the morphological, anatomical and phytochemical changes in response to UV-A exposure are generally understudied in the Phyllanthaceae. Therefore, we evaluated the effects of UV-A radiation on plant development and leaf anatomy, as well as the production of secondary metabolites and the contents of carotenoids and chlorophylls a and b, in P. tenellus. To accomplish this, in vitro cultures of P. tenellus were maintained for 60 days under white light (WL) and WL plus UV-A radiation. Results showed different phenotypic responses under additional UV-A, such as high phenolic metabolite production, increasing dimensions of abaxial epidermis and thickness of palisade parenchyma. Compared to plants cultured under WL, UV-A radiation caused damage to plant morphogenesis, including a reduced number of branches and shoots, consequently reducing the rate of proliferation. On the other hand, geraniin, ellagic acid and carotenoid contents increased after UV-A exposure, indicating that this light source is an important resource for inducing phenolic compounds.

  14. Neoplastic transformation of C3H mouse embryo 10T1/2 cells by 8-methoxypsoralen plus UVA radiation

    SciTech Connect

    Ananthaswamy, H.N.

    1985-08-01

    The effect of 8-methoxypsoralen plus UVA radiation (PUVA) on cell killing and induction of transformation was studied in the C3H mouse embryo 10T1/2 cell line. Dose-response data for both survival and transformation were obtained as a function of 8-methoxypsoralen (8-MOP) concentration and UVA dose. PUVA treatment caused cell death and induced transformation in a dose-dependent manner. Treatment of cells with 8-MOP alone (10 micrograms/ml) or UVA alone (90 J/m2) had no effect on either cell killing or transformation. The product of 8-MOP concentration and UVA dose calculated at 10% survival and 10(-3) transformation frequency levels were quite similar regardless of 8-MOP concentration or UVA dose. This suggests that there exists a simple reciprocal relationship between 8-MOP concentration and UVA dose. Both type II and type III foci induced by PUVA treatment were tumorigenic in vivo. These data provide further evidence for the carcinogenicity of PUVA treatment. In addition, the system described here could serve as a valuable model for studying the relationships between transformation and the specific cellular and molecular lesions induced by PUVA treatment.

  15. Governance of Cutaneous Photocarcinogenesis by Chronic UVA-Exposed Dermal Fibroblasts

    DTIC Science & Technology

    2014-09-01

    melanoma risk. Using a 2-chamber model, we show that UVA-exposed target cells induce an intercellular oxidative signaling to non-irradiated bystander...TERMS Carcinogenesis, melanoma , ultraviolet radiation 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a...UV radiation and is also the predominant constituent of indoor sunlamps, both of which have been shown to increase cutaneous melanoma risk. Using

  16. The bystander effect is a novel mechanism of UVA-induced melanogenesis.

    PubMed

    Nishiura, Hideki; Kumagai, Jun; Kashino, Genro; Okada, Takuya; Tano, Keizo; Watanabe, Masami

    2012-01-01

    We successfully identified the bystander effect in B16 murine melanoma cells exposed to UVA irradiation. The effect was identified based on melanogenesis following the medium transfer of the B16 cells, which had been cultured for 24 h after being exposed to UVA irradiation, to nonirradiated cells (bystander cells). Our confirmation study of the functional mechanism of bystander cells confirmed the reduced levels of mitochondrial membrane potential 1-4 h after the medium transfer. In addition, we observed increased levels of intracellular oxidation after 9-12 h, and the generation of melanin radicals, including long-lived radicals, 24 h after medium transfer. Further analysis of bystander factors revealed that the administration of EGTA treatment at the time of medium transfer led to an inhibition of melanogenesis and to neutralization of the mitochondrial membrane potential level, as well as to the restoration of intracellular oxidation levels to those of controls. The results demonstrated that the UVA irradiation bystander effect in B16 cells, as indicated by melanogenesis, was induced by the increase in intracellular oxidation due to the mitochondrial activity of calcium ions, which were among the bystander factors involved in the increase.

  17. Bacteria and fungi inactivation by photocatalysis under UVA irradiation: liquid and gas phase.

    PubMed

    Rodrigues-Silva, Caio; Miranda, Sandra M; Lopes, Filipe V S; Silva, Mário; Dezotti, Márcia; Silva, Adrián M T; Faria, Joaquim L; Boaventura, Rui A R; Vilar, Vítor J P; Pinto, Eugénia

    2016-06-29

    In the last decade, environmental risks associated with wastewater treatment plants (WWTPs) have become a concern in the scientific community due to the absence of specific legislation governing the occupational exposure limits (OEL) for microorganisms present in indoor air. Thus, it is necessary to develop techniques to effectively inactivate microorganisms present in the air of WWTPs facilities. In the present work, ultraviolet light A radiation was used as inactivation tool. The microbial population was not visibly reduced in the bioaerosol by ultraviolet light A (UVA) photolysis. The UVA photocatalytic process for the inactivation of microorganisms (bacteria and fungi, ATCC strains and isolates from indoor air samples of a WWTP) using titanium dioxide (TiO2 P25) and zinc oxide (ZnO) was tested in both liquid-phase and airborne conditions. In the slurry conditions at liquid phase, P25 showed a better performance in inactivation. For this reason, gas-phase assays were performed in a tubular photoreactor packed with cellulose acetate monolithic structures coated with P25. The survival rate of microorganisms under study decreased with the catalyst load and the UVA exposure time. Inactivation of fungi was slower than resistant bacteria, followed by Gram-positive bacteria and Gram-negative bacteria. Graphical abstract Inactivation of fungi and bacteria in gas phase by photocatalitic process performed in a tubular photoreactor packed with cellulose acetate monolith structures coated with TiO2.

  18. Luteolin decreases the UVA-induced autophagy of human skin fibroblasts by scavenging ROS

    PubMed Central

    Yan, Miaomiao; Liu, Zhongrong; Yang, Huilan; Li, Cuihua; Chen, Hulin; Liu, Yan; Zhao, Minling; Zhu, Yingjie

    2016-01-01

    Luteolin (LUT) is a flavone, which is universally present as a constituent of traditional Chinese herbs, and certain vegetables and spices, and has been demonstrated to exhibit potent radical scavenging and cytoprotective properties. Although LUT has various beneficial effects on health, the effects of LUT on the protection of skin remain to be fully elucidated. The present study investigated whether LUT can protect human skin fibroblasts (HSFs) from ultraviolet (UV) A irradiation. It was found that, following exposure to different doses of UVA irradiation, the HSFs exhibited autophagy, as observed by fluorescence and transmission electron microscopy, and reactive oxygen species (ROS) bursts, analyzed by flow cytometry, to differing degrees. Following incubation with micromolar concentrations of LUT, ROS production decreased and autophagy gradually declined. In addition, the expression of hypoxia-inducible factor-1α and the classical autophagy-associated proteins, LC3 and Beclin 1 were observed by western blotting. Western blot analysis showed that the expression levels of HIF-1α, LC3-II and Beclin 1 gradually decreased in the UVA-irradiated HSFs following treatment with LUT. These data indicated that UVA-induced autophagy was mediated by ROS, suggesting the possibility of resistance against UV by certain natural antioxidants, including LUT. PMID:27430964

  19. Lactobacillus sakei lipoteichoic acid inhibits MMP-1 induced by UVA in normal dermal fibroblasts of human.

    PubMed

    You, Ga-Eun; Jung, Bong-Jun; Kim, Hye-Rim; Kim, Han-Geun; Kim, Tae-Rahk; Chung, Dae-Kyun

    2013-10-28

    Human skin is continuously exposed to ultraviolet (UV)-induced photoaging. UVA increases the activity of MMP-1 in dermal fibroblasts through mitogen-activated protein kinase (MAPK), p38, signaling. The irradiation of keratinocytes by UVA results in the secretion of the inflammatory cytokine, tumor necrosis factor-α (TNF-α), and the stimulation of MMP-1 in normal human dermal fibroblasts (NHDFs). Lipoteichoic acid (LTA) is a component of the cell wall of gram-positive Lactobacillus spp. of bacteria. LTA is well known as an anti-inflammation molecule. LTA of the bacterium Lactobacillus plantarum has an anti-photoaging effect, but the potential anti-photoaging effect of the other bacteria has not been examined to date. The current study showed that L. sakei LTA (sLTA) has an immune modulating effect in human monocyte cells. Our object was whether inhibitory effects of sLTA on MMP-1 are caused from reducing the MAPK signal in NHDFs. It inhibits MMP-1 and MAPK signaling induced by UVA in NHDFs. We also confirmed effects of sLTA suppressing TNF-α inducing MMP-1 in NHDFs.

  20. The stress caused by nitrite with titanium dioxide nanoparticles under UVA irradiation in human keratinocyte cell.

    PubMed

    Tu, Min; Huang, Yi; Li, Hai-Ling; Gao, Zhong-Hong

    2012-09-04

    Our previous work found that in the presence of nitrite, titanium dioxide nanoparticles can cause protein tyrosine nitration under UVA irradiation in vivo. In this paper, the human keratinocyte cells was used as a skin cell model to further study the photo-toxicity of titanium dioxide nanoparticles when nitrite was present. The results showed that nitrite increased the photo-toxicity of titanium dioxide in a dose-dependant manner, and generated protein tyrosine nitration in keratinocyte cells. Morphological study of keratinocyte cells suggested a specific apoptosis mediated by apoptosis inducing factor. It was also found the main target nitrated in cells was cystatin-A, which expressed abundantly in cytoplasm and functioned as a cysteine protease inhibitor. The stress induced by titanium dioxide with nitrite under UVA irradiation in human keratinocyte cells appeared to trigger the apoptosis inducing factor mediated cell death and lose the inhibition of active caspase by cystatin-A. We conclude that nitrite can bring new damage and stress to human keratinocyte cells with titanium dioxide nanoparticles under UVA irradiation.

  1. The human melanocyte as a particular target for UVA radiation and an endpoint for photoprotection assessment.

    PubMed

    Marrot, L; Belaidi, J P; Meunier, J R; Perez, P; Agapakis-Causse, C

    1999-06-01

    The induction of DNA breaks by UVA (320-400 nm) in the nucleus of normal human melanocytes in culture was investigated using single cell gel electrophoresis, also called the comet assay. Endogenous pigment and/or melanin-related molecules were found to enhance DNA breakage: comets were more intense in melanocytes than in fibroblasts, in cells with high melanin content or after stimulation of melanogenesis by supplying tyrosine in the culture medium. After UVA doses where strong comets were observed, neither cytotoxicity nor stimulation of tyrosinase activity were detected. However, the accumulation of p53 protein suggested that cells reacted to genotoxic stress under these experimental conditions. The same approach was used to compare two sunscreens with identical sun protection factors but different UVA protection factors. The results presented in this paper suggest that human melanocytes may be used as a target cell to evidence broadspectrum photoprotection. Moreover, these data appear to be helpful in getting a better understanding of the role of sunlight in the initiating steps of melanocyte transformation.

  2. Evaluation of UVA-induced oxidative stress using a highly sensitive chemiluminescence method

    NASA Astrophysics Data System (ADS)

    Gao, Bo; Xing, Da; Zhu, Debin

    2005-02-01

    Oxidative stress is mainly mediated by reactive oxygen species (ROS). Evaluation of oxidative stress is helpful for choosing an appropriate method to protect the organism from the oxidative damage. In this study, a highly sensitive and simple chemiluminescence method is presented for the evaluation of radiation-induced oxidative stress in human peripheral lymphocytes. The lymphocytes were irradiated by ultraviolet radiation (320-400nm, UVA) with different doses. The ROS generated by the lymphocytes was detected by chemiluminescence method, using a highly sensitive chemiluminescence probe 2-methyl-6-(p-methoxyphenyl)-3,7-dihydroimidazo[1,2-α] pyrazin-3-one (MCLA). The cell viability was detected with Cell Counting Kit-8 (CCK-8). The malondialdehyde (MDA), a marker of lipid peroxidation and oxidative stress, and the total antioxidant capacity (TAC), a parameter that is taken as evidence of oxidative stress, were measured too. The results show that both chemiluminescence intensity, cell mortality and MDA concentration of lymphocytes grow with the increase of UVA dose range from 0.5 to 8 J/cm2, while the TAC decreases. There exists a positive relationship between cell oxidative damage degree and the chemiluminescence intensity of lymphocytes. This highly sensitive chemiluminescence method would potentially provide an easy way to evaluate the level of UVA-induced oxidative stress readily, sensitively and rapidly

  3. Mechanism of Aloe Vera extract protection against UVA: shelter of lysosomal membrane avoids photodamage.

    PubMed

    Rodrigues, Daniela; Viotto, Ana Cláudia; Checchia, Robert; Gomide, Andreza; Severino, Divinomar; Itri, Rosangela; Baptista, Maurício S; Martins, Waleska Kerllen

    2016-03-01

    The premature aging (photoaging) of skin characterized by wrinkles, a leathery texture and mottled pigmentation is a well-documented consequence of exposure to sunlight. UVA is an important risk factor for human cancer also associated with induction of inflammation, immunosuppression, photoaging and melanogenesis. Although herbal compounds are commonly used as photoprotectants against the harmful effects of UVA, the mechanisms involved in the photodamage are not precisely known. In this study, we investigated the effects of Aloe Vera (Aloe barbadensis mil) on the protection against UVA-modulated cell killing of HaCaT keratinocytes. Aloe Vera exhibited the remarkable ability of reducing both in vitro and in vivo photodamage, even though it does not have anti-radical properties. Interestingly, the protection conferred by Aloe Vera was associated with the maintenance of membrane integrity in both mimetic membranes and intracellular organelles. The increased lysosomal stability led to a decrease in lipofuscinogenesis and cell death. This study explains why Aloe Vera extracts offer protection against photodamage at a cellular level in both the UV and visible spectra, leading to its beneficial use as a supplement in protective dermatological formulations.

  4. UVA-mediated down-regulation of MMP-2 and MT1-MMP coincides with impaired angiogenic phenotype of human dermal endothelial cells.

    PubMed

    Cauchard, Jean-Hubert; Robinet, Arnaud; Poitevin, Stéphane; Bobichon, Hélene; Maziere, Jean-Claude; Bellon, Georges; Hornebeck, William

    2006-06-30

    UVA irradiation, dose-dependently (5-20 J/cm2), was shown to impair the morphogenic differentiation of human microvascular endothelial cells (HMECs) on Matrigel. Parallely, UVA down-regulated the expression of MMP-2 and MT1-MMP, both at the protein and the mRNA levels. On the contrary, the production of MMP-1 and TIMP-1 by HMECs increased following UVA treatment. The inhibitory effect of UVA on MMP expression and pseudotubes formation was mediated by UVA-generated singlet oxygen (1O2). The contribution of MT1-MMP, but not TIMP-1, to the regulation of HMECs' angiogenic phenotype following UVA irradiation was suggested using elastin-derived peptides and TIMP-1 blocking antibody, respectively.

  5. UVA-mediated down-regulation of MMP-2 and MT1-MMP coincides with impaired angiogenic phenotype of human dermal endothelial cells

    SciTech Connect

    Cauchard, Jean-Hubert; Robinet, Arnaud; Poitevin, Stephane; Bobichon, Helene; Maziere, Jean-Claude; Bellon, Georges; Hornebeck, William . E-mail: william.hornebeck@univ-reims.fr

    2006-06-30

    UVA irradiation, dose-dependently (5-20 J/cm{sup 2}), was shown to impair the morphogenic differentiation of human microvascular endothelial cells (HMECs) on Matrigel. Parallely, UVA down-regulated the expression of MMP-2 and MT1-MMP, both at the protein and the mRNA levels. On the contrary, the production of MMP-1 and TIMP-1 by HMECs increased following UVA treatment. The inhibitory effect of UVA on MMP expression and pseudotubes formation was mediated by UVA-generated singlet oxygen ({sup 1}O{sub 2}). The contribution of MT1-MMP, but not TIMP-1, to the regulation of HMECs' angiogenic phenotype following UVA irradiation was suggested using elastin-derived peptides and TIMP-1 blocking antibody, respectively.

  6. Photochemopreventive effect of pomegranate fruit extract on UVA-mediated activation of cellular pathways in normal human epidermal keratinocytes.

    PubMed

    Syed, Deeba N; Malik, Arshi; Hadi, Naghma; Sarfaraz, Sami; Afaq, Farrukh; Mukhtar, Hasan

    2006-01-01

    UVA is the major portion (90-99%) of solar radiation reaching the surface of the earth and has been described to lead to formation of benign and malignant tumors. UVA-mediated cellular damage occurs primarily through the release of reactive oxygen species and is responsible for immunosuppression, photodermatoses, photoaging and photocarcinogenesis. Pomegranate fruit extract (PFE) possesses strong antioxidant and anti-inflammatory properties. Our recent studies have shown that PFE treatment of normal human epidermal keratinocytes (NHEK) inhibits UVB-mediated activation of MAPK and NF-kappaB pathways. Signal transducers and activators of transcription 3 (STAT3), Protein Kinase B/AKT and Map Kinases (MAPKs), which are activated by a variety of factors, modulate cell proliferation, apoptosis and other biological activities. The goal of this study was to determine whether PFE affords protection against UVA-mediated activation of STAT3, AKT and extracellular signal-regulated kinase (ERK1/2). Immunoblot analysis demonstrated that 4 J/cm2 of UVA exposure to NHEK led to an increase in phosphorylation of STAT3 at Tyr705, AKT at Ser473 and ERK1/2. Pretreatment of NHEK with PFE (60-100 microg/mL) for 24 h before exposure to UVA resulted in a dose-dependent inhibition of UVA-mediated phosphorylation of STAT3 at Tyr705, AKT at Ser473 and ERK1/2. mTOR, structurally related to PI3K, is involved in the regulation of p70S6K, which in turn phosphorylates the S6 protein of the 40S ribosomal subunit. We found that UVA radiation of NHEK resulted in the phosphorylation of mTOR at Thr2448 and p70S6K at Thr421/Ser424. PFE pretreatment resulted in a dose-dependent inhibition in the phosphorylation of mTOR at Thr2448 and p70S6K at Thr421/Ser424. Our data further demonstrate that PFE pretreatment of NHEK resulted in significant inhibition of UVA exposure-mediated increases in Ki-67 and PCNA. PFE pretreatment of NHEK was found to increase the cell-cycle arrest induced by UVA in the G1 phase of

  7. Electron spin resonance detection of oxygen radicals released by UVA-irradiated human fibroblasts

    NASA Astrophysics Data System (ADS)

    Souchard, J. P.; Pierlot, G.; Barbacanne, M. A.; Charveron, M.; Bonafé, J.-L.; Nepveu, F.

    1999-01-01

    This work reports the electron spin resonance (ESR) detection of oxygenated radicals (OR) released by cultured human fibroblasts after UVA (365 nm) exposure. 5,5-dimethyl-pyrroline-N-oxide (DMPO) was used as spin trap. After a UVA irradiation of one hour, followed by a latent period of at least 45 min., and an incubation time of 30 min. in a trapping medium containing DMPO, glucose, Na^+, K+ and Ca2+ an ESR signal was recorded. By contrast, an ESR signal was produced after only 15 min. incubation when calcium ionophore A23187 was used. Although the ESR signal was characteristic of the hydroxyl adduct DMPO-OH, the use of catalase and superoxide dismutase (SOD) revealed that UVA stimulated fibroblasts released the superoxide anion O2- in the medium. SOD, vitamin C and (+)-catechin inhibited the release of superoxide generated by human fibroblasts stimulated with A23187 calcium ionophore at 5 units/ml, 10-5 M and 2× 10-4 M, respectively. Dans ce travail nous présentons la détection par résonance de spin électronique (RSE) de radicaux oxygénés (RO) libérés par des fibroblastes humains en culture après irradiation aux UVA (365 nm). Le 5,5-diméthyl-1-pyrroline-N-oxyde (DMPO) a été utilisé comme piégeur de spin. Après une irradiation aux UVA d'une heure, suivie d'une période de latence d'au moins 45 min. et d'une incubation de 30 min. dans un milieu de piégeage composé de DMPO, glucose, Na^+, K+ et Ca2+, un signal RPE est enregistré. L'ionophore calcique A23187 entraîne l'apparition d'un signal RPE après seulement 15 min. d'incubation. Bien que le signal RPE obtenu corresponde à l'adduit DMPO-OH du radical hydroxyle, l'utilisation de catalase et de superoxyde dismutase (SOD) a révélé que les fibroblastes libéraient l'anion superoxyde dans le milieu de culture. Sur ce modèle cellulaire la SOD, la vitamine C et la (+) catéchine inhibent la production du radical superoxyde aux concentrations respectivement de 5 unités/ml, 10-5 M et 2× 10-4M.

  8. The lazaroid tirilazad is a new inhibitor of direct and indirect UVA-induced lipid peroxidation in human dermal fibroblasts.

    PubMed

    Dissemond, J; Schneider, L A; Wlaschek, M; Brauns, T C; Goos, M; Scharffetter-Kochanek, K

    2003-12-01

    Lipid peroxidation caused by oxidative stress within the tissue leads to destruction and dysfunction of cellular membranes. Human dermal fibroblasts in the skin are subject to constant photooxidative stress caused mainly by deeply penetrating UVA irradiation. Therefore, the membrane damage caused by this photooxidative stress may be a major promoter of photoaging and photocarcinogenic processes initiated and promoted by long-term UVA exposure of the skin. The oxidative destruction is counterbalanced by a complex network of enzymatic and nonenzymatic antioxidants creating the skin's line of defence against UVA-induced reactive oxygen species. The lazaroid tirilazad represents a new synthetic group of antioxidants with structural molecular similarity to glucocorticosteroids. We investigated the antioxidative capacity of tirilazad by determining its effects on the levels of malondialdehyde (MDA), as a marker of lipid peroxidation, induced directly or indirectly by UVA in human dermal fibroblasts. In a time- and dose-dependent kinetic, we demonstrated that fibroblasts incubated with tirilazad are well protected against subsequent UVA irradiation and show no increase in MDA levels similar to the unirradiated controls. This was also observed when lipid peroxidation was caused chemically by incubation of human dermal fibroblasts with 200 micro M Fe(3+)-citrate and 1 m M ascorbyl phosphate as a model of indirect UVA-induced skin damage. Lysates of fibroblasts treated this way showed a tenfold increase in MDA levels, whereas preincubation with tirilazad resulted in a significantly lower increase in MDA levels. Furthermore, in a comparison with the well-established radical scavenger Trolox, an alpha-tocopherol analogue, tirilazad offered better protection to the membranes. Our results demonstrate for the first time that the lazaroid tirilazad is an effective inhibitor of direct and indirect UVA-induced increases in MDA as a marker of lipid peroxidation in human dermal

  9. Use of potassium bicarbonate (Armicarb) on the control of powdery mildew (Sphaerotheca mors-uvae) of gooseberry (Ribes uva-crispa).

    PubMed

    Wenneker, M; Kanne, J

    2010-01-01

    Powdery mildew (Sphaerotheca mors-uvae) severely infects young shoots, stems and fruits of gooseberry (Ribes uva-crispa). Environmental friendly and biological control measures are being sought throughout the world. Especially in organic gooseberry growing effective control measures are needed, because powdery mildew infections may result in a total loss of the crop. In organic currant growing the number of adequate control methods is very limited. Sulphur as a fungicide against powdery mildew in e.g. gooseberry or table grape growing is not recommendable due to possible bleaching of berries and scorching of tender shoots. Various bicarbonate salts are suggested as a good option to control powdery mildew. In a field trial the effect of potassium bicarbonate (Armicarb) on the on the control of powdery mildew of gooseberry was evaluated. Four treatments; i.e. two preventive strategies and two curative strategies, were applied. PLants were sprayed until runoff. The percent of infected fruits and disease severity were assessed. In the unsprayed control plots very high disease incidences were observed; on average more than 90% of the berries were infected with powdery mildew. The weekly (preventive) spray applications with potassium carbonate reduced the disease incidences on fruits significantly. On average approximately 10% of the fruits were affected by powdery mildew. However, the number of spray applications was high. In conclusion, our results indicate that applications of potassium bicarbonate (as Armicarb) are effective in reducing the incidence and severity of American powdery mildew in gooseberry. Early spray applications are necessary to protect berries against powdery mildew infections. Future research will focus on reducing the number of applications, e.g. warning models based on powdery mildew of rose (Sphaerotheca pannosa).

  10. Solar-UV-signature mutation prefers TCG to CCG: extrapolative consideration from UVA1-induced mutation spectra in mouse skin.

    PubMed

    Ikehata, Hironobu; Kumagai, Jun; Ono, Tetsuya; Morita, Akimichi

    2013-08-01

    UVA1 exerts its genotoxicity on mammalian skin by producing cyclobutane pyrimidine dimers (CPDs) in DNA and preferentially inducing solar-UV-signature mutations, C → T base substitution mutations at methylated CpG-associated dipyrimidine (Py-mCpG) sites, as demonstrated previously using a 364 nm laser as a UVA1 source and lacZ-transgenic mice that utilize the transgene as a mutational reporter. In the present study, we confirmed that a broadband UVA1 source induced the same mutation profiles in mouse epidermis as the UVA1 laser, generalizing the previous result from a single 364 nm to a wider wavelength range of UVA1 (340-400 nm). Combined with our previous data on the mutation spectra induced in mouse epidermis by UVB, UVA2 and solar UVR, we proved that the solar-UV-signature mutation is commonly observed in the wavelength range from UVB to UVA, and found that UVA1 induces this mutation more preferentially than the other shorter wavelength ranges. This finding indicates that the solar-UV-signature mutation-causing CPDs, which are known to prefer Py-mCpG sites, could be produced with the energy provided by the longer wavelength region of UVR, suggesting a photochemical reaction through the excitation of pyrimidine bases to energy states that can be accomplished by absorption of even low-energy UVR. On the other hand, the lower proportions of solar-UV-signature mutations observed in the mutation spectra for UVB and solar UVR indicate that the direct photochemical reaction through excited singlet state of pyrimidine bases, which can be accomplished only by high-energy UVR, is also involved in the mutation induction at those shorter wavelengths of UVR. We also found that the solar-UV signature prefers 5'-TCG-3' to 5'-CCG-3' as mutational target sites, consistent with the fact that UVA induces CPDs selectively at thymine-containing dipyrimidine sites and that solar UVR induces them preferably at Py-mCpG sites. However, the mutation spectrum in human p53 gene from non

  11. Incorporation in lipid microparticles of the UVA filter, butyl methoxydibenzoylmethane combined with the UVB filter, octocrylene: effect on photostability.

    PubMed

    Scalia, Santo; Mezzena, Matteo

    2009-01-01

    The aim of this study was to reduce the photoinstability of butyl methoxydibenzoylmethane (BMDBM), the most widely used UVA filter, by incorporating it in lipid microparticles (LMs) alone or together with the UVB filter octocrylene (OCR), acting also as photostabilizer. Microparticles loaded with BMDBM or with combined BMDBM and OCR were produced by the hot emulsion technique, using glyceryl behenate as lipid material and poloxamer 188 as surfactant. The LMs were characterized by release studies, scanning electron microscopy, and powder X-ray diffractometry. The BMDBM and OCR loading was 15.2% and 10.6%, respectively. In order to reproduce the conditions prevalent in commercial sunscreen products, the photoprotective efficacy of the LMs was evaluated after their introduction in a model cream (oil-in-water emulsion) containing a mixture of UVA and UVB filters. A small but statistically significant decrease in BMDBM photodegradation was obtained when the UVA filter was encapsulated alone into the LMs (the extent of degradation was 28.6% +/-2.4 for non-encapsulated BMDBM and 26.0% +/-2.5 for BMDBM-loaded microparticles). On the other hand, the co-loading of OCR in the LMs produced a more marked reduction in the light-induced decomposition of microencapsulated BMDBM (the UVA filter loss was 21.5% +/-2.2). Therefore, incorporation in lipid microparticles of BMDBM together with the sunscreen OCR is more effective in enhancing the UVA filter photostability than LMs loaded with BMDBM alone.

  12. Synthesis and luminescent properties of ternary complex Eu(UVA)3Phen in nano-TiO2

    NASA Astrophysics Data System (ADS)

    Lü, Yu-guang; Gong, Zhong-ping; Gao, Hong-bing; Zhou, Shu-jing; Lü, Kui-lin; Wang, Ying; A, Du; Du, Hao-ran; Zhang, Li; Zhang, Fu-jun

    2015-01-01

    By introducing 2-hydroxy-4-methoxy-benzophenone (UVA) and 1,10-phenanthroline (Phen) as the ligands, the ternary rare earth complex of Eu(UVA)3Phen is synthesized, and it is characterized by elemental analysis, mass spectra (MS) and infrared (IR) and ultraviolet (UV) spectroscopy. Results show that the Eu(III) in complex emits strong red luminescence when it is excited by UV light, and it has higher sensitized luminescent efficiency and longer lifetime. The organic-inorganic thin film of complex Eu(UVA)3Phen doped with nano-TiO2 is prepared, and the nano-TiO2 is used in the luminescence layer to change the luminescence property of Eu(UVA)3Phen. It is found that there is an efficient energy transfer process between ligands and metal ions. Moreover, in an indium tin oxide (ITO)/poly(N-vinylcar-bazole) (PVK)/Eu(UVA)3Phen/Al device, Eu3+ can be excited by intramolecular ligand-to-metal energy transfer process. The main peak of emission at 613 nm is attributed to 5D0→7F2 transition of the Eu3+, and this process results in the enhanced red emission.

  13. Thymol and Thymus Vulgaris L. activity against UVA- and UVB-induced damage in NCTC 2544 cell line.

    PubMed

    Calò, Rossella; Visone, Clementina M; Marabini, Laura

    2015-09-01

    Many authors focused on the research of natural compounds in order to protect skin from indirect (UVA) and direct (UVB) ultraviolet radiation side effects. The aim of this study to evaluate the protective effect of a dry extract from T. vulgaris L. and of its major synthetic compound thymol (about 60%), against oxidative and genotoxic UVA- and UVB damage. Experiments were reproduced in a low differentiated keratinocytes cell line (NCTC 2544) Cells were pretreated for 1h, in serum-free medium, with thymol (1μg/mL) or T. vulgaris L. (1.82μg/mL) then exposed to different UVA (8-24J/cm(2)) or UVB doses (0.016-0.72J/cm(2)). Immediately after the UV exposure the intracellular redox status was evaluated by ROS quantification and by LPO. Genotoxic aspects were evaluated 24h after the end of irradiations using the alkaline comet assay, the micronucleus formation assay and the immunostaining of phosphorylated H2AX histone protein (detected 1h after the end of UV exposure). Thymol and T. vulgaris L. extract inhibited ROS generation in UVA and UVB-irradiated cells. On the contrary, MDA formation was reduced only in UVA treated cells. Both agents decreased the DNA damage evaluated by the alkaline comet assay, but not in the micronucleus and H2AX tests probably because of the severity of damage (double strands) detected.

  14. Photo-oxidation of 6-thioguanine by UVA: the formation of addition products with low molecular weight thiol compounds.

    PubMed

    Ren, Xiaolin; Xu, Yao-Zhong; Karran, Peter

    2010-01-01

    The thiopurine, 6-thioguanine (6-TG) is present in the DNA of patients treated with the immunosuppressant and anticancer drugs azathioprine or mercaptopurine. The skin of these patients is selectively sensitive to UVA radiation-which comprises >90% of the UV light in incident sunlight-and they suffer high rates of skin cancer. UVA irradiation of DNA 6-TG produces DNA lesions that may contribute to the development of cancer. Antioxidants can protect 6-TG against UVA but 6-TG oxidation products may undergo further reactions. We characterize some of these reactions and show that addition products are formed between UVA-irradiated 6-TG and N-acetylcysteine and other low molecular weight thiol compounds including β-mercaptoethanol, cysteine and the cysteine-containing tripeptide glutathione (GSH). GSH is also adducted to 6-TG-containing oligodeoxynucleotides in an oxygen- and UVA-dependent nucleophilic displacement reaction that involves an intermediate oxidized 6-TG, guanine sulfonate (G(SO3) ). These photochemical reactions of 6-TG, particularly the formation of a covalent oligodeoxynucleotide-GSH complex, suggest that crosslinking of proteins or low molecular weight thiol compounds to DNA may be a previously unrecognized hazard in sunlight-exposed cells of thiopurine-treated patients.

  15. Photolytic degradation of sulfamethoxazole and trimethoprim using UV-A, UV-C and vacuum-UV (VUV).

    PubMed

    Kim, Hyun Young; Kim, Tae-Hun; Yu, Seungho

    2015-01-01

    The photolytic degradation of the non-degradable pharmaceuticals sulfamethoxazole (SMX) and trimethoprim (TMP) in an aqueous solution was investigated using three kinds of low-pressure mercury lamp UV-A (352 nm), UV-C (254 nm), and vacuum-UV (VUV, 185 nm and 254 nm). The degradation rates were highly dependent on the target compounds as well as the UV sources. No degradation of the target compounds was observed using UV-A treatment, because there was no overlap between the UV-A emission spectrum and absorption spectrum of the target compounds. On the other hand, UVC and VUV revealed higher reactivity. The results also indicated that SMX had a greater potential to react photochemically than TMP. Among the UV sources, VUV was the most effective process for the degradation of target compounds. Furthermore, the addition of oxidants such as hydrogen peroxide (H2O2) and sodium persulfate (Na2S2O8) to the reaction system improved the overall degradation rate significantly.The experimental results for the VUV-irradiated samples with the addition of methanol as a hydroxyl radical scavenger revealed that hydroxyl radicals contribute significantly to the elimination of the target compound. Overall, the degradation rate of the target compounds was in the order: VUV = UV-C > UV-A for sulfamethoxazole and VUV/H2O2 > VUV/ Na2S2O8 > VUV >UV-C >UV-A for trimethoprim.

  16. Comparative Analysis of Differentially Expressed Genes in Shewanella oneidensis MR-1 following Exposure to UVC, UVB, and UVA Radiation†

    PubMed Central

    Qiu, Xiaoyun; Sundin, George W.; Wu, Liyou; Zhou, Jizhong; Tiedje, James M.

    2005-01-01

    We previously reported that Shewanella oneidensis MR-1 is highly sensitive to UVC (254 nm), UVB (290 to 320 nm), and UVA (320 to 400 nm). Here we delineated the cellular response of MR-1 to UV radiation damage by analyzing the transcriptional profile during a 1-h recovering period after UVC, UVB, and UVA exposure at a dose that yields about a 20% survival rate. Although the SOS response was observed with all three treatments, the induction was more robust in response to short-wavelength UV radiation (UVB and UVC). Similarly, more prophage-related genes were induced by short-wavelength UV radiation. MR-1 showed an active detoxification mechanism in response to UVA, which included the induction of antioxidant enzymes and iron-sequestering proteins to scavenge reactive oxygen species. In addition, a great number of genes encoding multidrug and heavy metal efflux pumps were induced following UVA irradiation. Our data suggested that activation of prophages appears the major lethal factor in MR-1 following UVC or UVB irradiation, whereas oxidative damage contributes greatly to the high UVA sensitivity in MR-1. PMID:15866945

  17. Exposure to low UVA doses increases KatA and KatB catalase activities, and confers cross-protection against subsequent oxidative injuries in Pseudomonas aeruginosa.

    PubMed

    Pezzoni, Magdalena; Tribelli, Paula M; Pizarro, Ramón A; López, Nancy I; Costa, Cristina S

    2016-05-01

    Solar UVA radiation is one of the main environmental stress factors for Pseudomonas aeruginosa. Exposure to high UVA doses produces lethal effects by the action of the reactive oxygen species (ROS) it generates. P. aeruginosa has several enzymes, including KatA and KatB catalases, which provide detoxification of ROS. We have previously demonstrated that KatA is essential in defending P. aeruginosa against high UVA doses. In order to analyse the mechanisms involved in the adaptation of this micro-organism to UVA, we investigated the effect of exposure to low UVA doses on KatA and KatB activities, and the physiological consequences. Exposure to UVA induced total catalase activity; assays with non-denaturing polyacrylamide gels showed that both KatA and KatB activities were increased by radiation. This regulation occurred at the transcriptional level and depended, at least partly, on the increase in H2O2 levels. We demonstrated that exposure to low UVA produced a protective effect against subsequent lethal doses of UVA, sodium hypochlorite and H2O2. Protection against lethal UVA depends on katA, whilst protection against sodium hypochlorite depends on katB, demonstrating that different mechanisms are involved in the defence against these oxidative agents, although both genes can be involved in the global cellular response. Conversely, protection against lethal doses of H2O2 could depend on induction of both genes and/or (an)other defensive factor(s). A better understanding of the adaptive response of P. aeruginosa to UVA is relevant from an ecological standpoint and for improving disinfection strategies that employ UVA or solar irradiation.

  18. Epidemiological support for an hypothesis for melanoma induction indicating a role for UVA radiation.

    PubMed

    Moan, J; Dahlback, A; Setlow, R B

    1999-08-01

    An hypothesis for melanoma induction is presented: UV radiation absorbed by melanin in melanocytes generates products that may activate the carcinogenic process. Products formed by UV absorption in the upper layers of the epidermis cannot diffuse down as far as to the melanocytes. Thus, melanin in the upper layer of the skin may be protective, while that in melanocytes may be photocarcinogenic. Observations that support this hypothesis include: (1) Africans with dark skin have a reduced risk of getting all types of skin cancer as compared with Caucasians, but the ratio of their incidence rates of cutaneous malignant melanoma to that of squamous cell carcinoma is larger than the corresponding ratio for Caucasians. (2) Albino Africans, as compared with normally pigmented Africans, seem to have a relatively small risk of getting cutaneous malignant melanomas compared to nonmelanomas. This is probably also true for albino and normally pigmented Caucasians. (3) Among sun-sensitive, poorly tanning persons, frequent UV exposures are associated with increased risk of melanoma, whereas among sun-resistant, well-tanning persons, increased frequency of exposure is associated with decreased melanoma risk. (4) It is likely that UVA, being absorbed by melanin, might have a melanoma-inducing effect. This is in agreement with some epidemiological investigations which indicate that sun-screen lotions may not protect sufficiently against melanoma induction. The relative latitude gradient for UVA is much smaller than that for UVB. The same is true for the relative latitude gradient of cutaneous malignant melanoma as compared with squamous cell carcinoma and basal cell carcinoma. Under the assumption that the average slopes of the curves relating incidence rates with fluences of carcinogenic UV radiation are similar for melanomas and nonmelanomas, these facts are in agreement with the assumption that UVA plays a significant role in the induction of melanomas in humans. This is in

  19. Contrasting patterns of tolerance between chemical and biological insecticides in mosquitoes exposed to UV-A.

    PubMed

    Tetreau, Guillaume; Chandor-Proust, Alexia; Faucon, Frédéric; Stalinski, Renaud; Akhouayri, Idir; Prud'homme, Sophie M; Raveton, Muriel; Reynaud, Stéphane

    2013-09-15

    Mosquitoes are vectors of major human diseases, such as malaria, dengue or yellow fever. Because no efficient treatments or vaccines are available for most of these diseases, control measures rely mainly on reducing mosquito populations by the use of insecticides. Numerous biotic and abiotic factors are known to modulate the efficacy of insecticides used in mosquito control. Mosquito breeding sites vary from opened to high vegetation covered areas leading to a large ultraviolet gradient exposure. This ecological feature may affect the general physiology of the insect, including the resistance status against insecticides. In the context of their contrasted breeding sites, we assessed the impact of low-energetic ultraviolet exposure on mosquito sensitivity to biological and chemical insecticides. We show that several mosquito detoxification enzyme activities (cytochrome P450, glutathione S-transferases, esterases) were increased upon low-energy UV-A exposure. Additionally, five specific genes encoding detoxification enzymes (CYP6BB2, CYP6Z7, CYP6Z8, GSTD4, and GSTE2) previously shown to be involved in resistance to chemical insecticides were found over-transcribed in UV-A exposed mosquitoes, revealed by RT-qPCR experiments. More importantly, toxicological bioassays revealed that UV-exposed mosquitoes were more tolerant to four main chemical insecticide classes (DDT, imidacloprid, permethrin, temephos), whereas the bioinsecticide Bacillus thuringiensis subsp. israelensis (Bti) appeared more toxic. The present article provides the first experimental evidence of the capacity of low-energy UV-A to increase mosquito tolerance to major chemical insecticides. This is also the first time that a metabolic resistance to chemical insecticides is linked to a higher susceptibility to a bioinsecticide. These results support the use of Bti as an efficient alternative to chemical insecticides when a metabolic resistance to chemicals has been developed by mosquitoes.

  20. Aerosol forcing efficiency in the UVA region from spectral solar irradiance measurements at an urban environment

    NASA Astrophysics Data System (ADS)

    Kazadzis, S.; Kouremeti, N.; Bais, A.; Kazantzidis, A.; Meleti, C.

    2009-06-01

    Spectral Ultraviolet (UV) measurements using a Brewer MKIII double spectroradiometer were used for the determination of the aerosol forcing efficiency (RFE) under cloud free conditions at Thessaloniki, Greece for the period 1998-2006. Using measured spectral UVA irradiance in combination with synchronous aerosol optical depth (AOD) measurements at 340 nm, we calculated the seasonal and the percent RFE changes with the help of radiative transfer model calculations used for cloud and aerosol free conditions reference. The calculated RFE for the 325-340 nm wavelength integral was found to be -0.71±0.30 W m-2/τs340 nm and corresponds to a mean calculated RFE% value of -15.2%±3.8% (2 σ) per unit of τs340 nm, for the whole period. This indicates a mean reduction of 15.2% of the 325-340 nm irradiance for a unit of aerosol optical depth slant column increase. Lower RFE% was found during summertime, which is a possible indication of lower absorbing aerosols. Mean AOD slant at 340 nm for the city of Thessaloniki were processed in combination with RFE% and a mean monthly UVA attenuation of ~10% for the whole period was revealed. The nine years' analysis results showed a reduction in RFE%, which provides a possible indication of the changes in the optical properties over the city area. If such changes are only due to changes in the aerosol absorbing properties, the above finding suggests a 2% per decade increase in UVA due to changes in the aerosol absorption properties, in addition to the calculated increase by 4.2%, which is attributed only to AOD decrease at Thessaloniki area over the 1998-2006 period.

  1. UV-A induced delayed development in the larvae of coral Seriatopora caliendrum.

    PubMed

    Zhou, Jie; Fan, Tung-Yung; Beardall, John; Gao, Kunshan

    2017-02-01

    Coral reefs are vulnerable to ultraviolet radiation (UVR, 280-400nm). Not only do the fluxes of UVR fluctuate daily, they are also increasing due to global ocean and atmospheric changes. The deleterious effects of UVR on scleractinian corals have been intensively studied, but much less is known about the response of corals in the early pre-settlement phase. In this study, we tested how UVR exposure affects survival and development of Seriatopora caliendrum larvae and examined the photophysiological changes induced in the symbiotic dinoflagellate Symbiodinium. Results showed that the contents of chl c and carotenoids normalized to the number of algae cells in the larvae decreased significantly when larvae were exposed to UVR compared to those protected from UVR, while the cell density of Symbiodinium was higher in UVR-exposed larvae. The effective photochemical efficiency of the symbiotic algae increased when cultured under PAR plus UV-A (here taken as 320-395nm). We further present the novel finding that during the development experiment, presence of UV-A induced a decline in the rates of metamorphosis and settlement, which disappeared when the larvae were also exposed to UV-B (here defined as 295-320nm). However, UVR had no distinguishable effect on the numbers of larvae that either survived, metamorphosed or settled by the end of the culture period. Therefore, it is concluded from this study that UV-A radiation may extend the planktonic duration of coral larvae, but not have an overall inhibitory effect on developmental outcomes.

  2. Mathematical modeling of cell proliferation dynamics in psoriatic epidermis sensitized by the furocoumarins under UVA radiation

    NASA Astrophysics Data System (ADS)

    Baskakov, Pavel V.; Stolnitz, Mikhail M.

    1997-02-01

    In the work the mathematical model is presented which describes the processes in the epidermis sensitized by the furocoumarins under UVA-radiation. The model describes the processes at three levels: molecular (the photochemical transformations of the psoralen molecules and their reactions with the DNA-molecules), cellular (proliferation, differentiation and repairing of injuries), and tissue (humoral regulation, space-time cell dynamics in the epidermis). The results of the numerical simulations of both the latent period and psoriasis manifestation are given. The therapeutical effect of the UV-radiation is considered in the framework of the model.

  3. Prediction of sun protection factors and UVA parameters of sunscreens by using a calibrated step film model.

    PubMed

    Herzog, Bernd; Mongiat, Sébastien; Quass, Katja; Deshayes, Cyrille

    2004-07-01

    At the stage of screening of new sun protection formulations, quick and inexpensive methods for estimation of the ultraviolet (UV) screening performance are highly desirable. It has been shown recently that apart from measurements of sun protection factors in vitro, calculations using a calibrated step film model are also a possibility. In the present investigation, further evidence for the usefulness of the step film model in terms of prediction of the sun protection factor is shown. In addition, it is demonstrated that parameters, which characterize the protection in the UVA range such as the UVA/UVB ratio and the critical wavelength can be calculated in good accordance with experimental data. Although with less accuracy, the estimation of UVA protection factors is also possible, if the photodegradation some filters undergo upon irradiation is taken into consideration.

  4. Tirilazad amelioriates extracellular effects of photooxidative stress by sealing the membrane of UVA irradiated human dermal fibroblasts.

    PubMed

    Schneider, Lars Alexander; Dissemond, Joachim; Schwamborn, Edith; Wlaschek, Meinhard; Brenneisen, Peter; Scharffetter-Kochanek, Karin

    2006-01-01

    The evaluation of antioxidant medication might provide further tools to protect the skin against the detrimental effects of photooxidative stress. In this context we have previously shown that the lazaroid tirilazad protects fibroblasts effectively against lipid peroxidation (LPO). Now we investigated whether and how tirilazad also influences two typical stress responses after UVA exposure, i.e. IL-6 and collagenase (MMP-1) release. Fibroblasts pre-incubated with tirilazad at a concentration of 30 microM show significantly less IL-6 in the extracellular medium after UVA exposure. Correspondingly, pre-incubation with tirilazad also significantly diminishes the extracellular MMP-1 protein concentration 24h post-irradiation. These effects observed are due to a membrane stabilisation, as tirilazad neither diminishes IL-6 mRNA production nor intracellular IL-6/MMP-1 protein levels after UVA exposure and thus most likely acts by sealing off the cell, delaying the typical leakage of IL-6 and MMP-1.

  5. Assessment of extracts of Helichrysum arenarium, Crataegus monogyna, Sambucus nigra in photoprotective UVA and UVB; photostability in cosmetic emulsions.

    PubMed

    Jarzycka, Anna; Lewińska, Agnieszka; Gancarz, Roman; Wilk, Kazimiera A

    2013-11-05

    The aim of our study was to investigate the photoprotective activity and photostability efficacy of sunscreen formulations containing Helichrysum arenarium, Sambucus nigra, Crataegus monogyna extracts and their combination. UV transmission of the emulsion films was performed by using diffuse transmittance measurements coupling to an integrating sphere. In vitro photoprotection and photostability efficacy were evaluated according to the following parameters: sun protection factor (SPF), UVA protection factor (PF-UVA), UVA/UVB ratio and critical wavelength (λc) before and after UV irradiation. The results obtained show that the formulations containing polyphenols fulfill the official requirements for sunscreen products due to their broad spectrum of UV protection combined with their high photostability and remarkable antioxidant properties. Therefore H. arenarium, S. nigra, C. monogyna extracts represent useful additives for cosmetic formulation.

  6. Solar UV-A and UV-B radiation fluxes at two Alpine stations at different altitudes

    NASA Astrophysics Data System (ADS)

    Blumthaler, M.; Ambach, W.; Rehwald, W.

    1992-03-01

    Daily totals of UV-A and UV-B radiation fluxes and global radiation were measured since 1981 at Jungfraujoch (3576 m) a.s.l.) and in Innsbruck (577 m a.s.l.) in their seasonal course. The altitude effect of annual totals yields 19%/1000 m (UV-B), 11%/1000 m (UV-A) and 9%/1000 m (global radiation) with reference to Innsbruck station. The ratio of the daily totals of UV-B/global radiation shows a significant seasonal course with the maximum in summer, whereas the ratio of the daily totals of UV-A/global radiation shows no significant seasonal variation. The biological effective doses of erythema reaction, delayed tanning and immediate tanning by UV-A and UV-B radiant exposure are reported in the seasonal course at Jungfraujoch and in Innsbruck.

  7. Chronic exposure to Rhodobacter sphaeroides extract Lycogen™ prevents UVA-induced malondialdehyde accumulation and procollagen I down-regulation in human dermal fibroblasts.

    PubMed

    Yang, Tsai-Hsiu; Lai, Ying-Hsiu; Lin, Tsuey-Pin; Liu, Wen-Sheng; Kuan, Li-Chun; Liu, Chia-Chyuan

    2014-01-23

    UVA contributes to the pathogenesis of skin aging by downregulation of procollagen I content and induction of matrix metalloproteinase (MMP)-associated responses. Application of antioxidants such as lycopene has been demonstrated as a convenient way to achieve protection against skin aging. Lycogen™, derived from the extracts of Rhodobacter sphaeroides, exerts several biological effects similar to that of lycopene whereas most of its anti-aging efficacy remains uncertain. In this study, we attempted to examine whether Lycogen™ could suppress malondialdehyde (MDA) accumulation and restore downregulated procollagen I expression induced by UVA exposure. In human dermal fibroblasts Hs68 cells, UVA repressed cell viability and decreased procollagen I protein content accompanied with the induction of MMP-1 and MDA accumulation. Remarkably, incubation with 50 µM Lycogen™ for 24 h ameliorated UVA-induced cell death and restored UVA-induced downregulation of procollagen in a dose-related manner. Lycogen™ treatment also prevented the UVA-induced MMP-1 upregulation and intracellular MDA generation in Hs68 cells. Activation of NFκB levels, one of the downstream events induced by UVA irradiation and MMP-1 induction, were also prevented by Lycogen™ administration. Taken together, our findings demonstrate that Lycogen™ may be an alternative agent that prevents UVA-induced skin aging and could be used in cosmetic and pharmaceutical applications.

  8. The tryptophan-derived endogenous arylhydrocarbon receptor ligand 6-formylindolo[3,2-b]carbazole (FICZ) is a nanomolar UVA-photosensitizer in epidermal keratinocytes

    PubMed Central

    Williams, Joshua D.; Cabello, Christopher M.; Qiao, Shuxi; Wondrak, Georg T.

    2014-01-01

    Endogenous UVA-chromophores may act as sensitizers of oxidative stress underlying cutaneous photoaging and photocarcinogenesis, but the molecular identity of non-DNA key chromophores displaying UVA-driven photodyamic activity in human skin remains largely undefined. Here we report that 6-formylindolo[3,2-b]carbazole (FICZ), a tryptophan photoproduct and endogenous high affinity aryl hydrocarbon receptor (AhR) agonist, acts as a nanomolar photosensitizer potentiating UVA-induced oxidative stress irrespective of AhR ligand activity. In human HaCaT and primary epidermal keratinocytes, photodynamic induction of apoptosis was elicited by the combined action of solar simulated UVA and FICZ, whereas exposure to the isolated action of UVA or FICZ did not impair viability. In a human epidermal tissue reconstruct, FICZ/UVA-cotreatment caused pronounced phototoxicity inducing keratinocyte cell death, and FICZ photodynamic activity was also substantiated in a murine skin exposure model. Array analysis revealed pronounced potentiation of cellular heat shock, ER stress, and oxidative stress response gene expression observed only upon FICZ/UVA-cotreatment. FICZ photosensitization caused intracellular oxidative stress, and comet analysis revealed introduction of formamidopyrimidine-DNA glycosylase (FPG)-sensitive oxidative DNA lesions suppressible by antioxidant cotreatment. Taken together, our data demonstrate that the endogenous AhR ligand FICZ displays nanomolar photodynamic activity representing a molecular mechanism of UVA-induced photooxidative stress potentially operative in human skin. PMID:25431849

  9. Positive photocontact responses are not elicited to sunscreen ingredients exposed to UVA prior to application onto the skin.

    PubMed

    Wahie, Shyamal; Lloyd, James J; Farr, Peter M

    2007-10-01

    Photocontact allergic reactions to sunscreen chemicals are investigated by photopatch testing. It has generally been assumed that for photocontact allergy to be shown, the putative pro-allergen must be in the skin at the time of ultraviolet A (UVA) exposure. However, this assumption has not, to our knowledge, been tested. The objective of this study was to determine whether positive photocontact responses can still be elicited when sunscreen chemicals are exposed to UVA prior to application onto the skin. 3 patients known to have positive photocontact reactions to a total of 6 sunscreen chemicals were studied. For conventional photopatch testing, patch test strips were applied onto the back and removed 1 D later, and the area was irradiated with UVA (5 J/cm(2)). For pre-irradiated testing, patches were exposed to the same dose of UVA immediately before application onto the back and then removed 1 D later. Skin responses were visually assessed by a blinded investigator 1 and 2 D after patch test removal. The same photocontact responses of the same magnitude, as previously documented for each patient, were seen at each of the conventional UVA-exposed patch test sites. However, in no patient was a positive response elicited at any of the sites where pre-irradiated patches had been applied. This study shows that positive photocontact responses to sunscreen chemicals do not occur when the putative pro-allergen is irradiated prior to application onto the skin. This suggests that for a photoallergic reaction to occur, the sunscreen chemical needs to be within the skin when activated by UVA.

  10. The effects of derivatives of the nitroxide tempol on UVA-mediated in vitro lipid and protein oxidation.

    PubMed

    Damiani, Elisabetta; Castagna, Riccardo; Greci, Lucedio

    2002-07-01

    Derivatives of tetramethylpiperidines are extensively employed in polymers to prevent photooxidation, and their stabilizing effect is attributed to the activity of the nitroxide radical derived from the parent amine. In this study, we examined the photoprotective effect of a commercial polymer photostabilizer, HALS-1, its corresponding nitroxide, bis(2,2,6,6-tetramethyl-piperidine-1-oxyl-4-yl)sebacate (TINO), and two derivatives of the piperidine nitroxide TEMPOL, 2,2,6,6-tetramethyl-piperidin-4-acetyloxy-1-oxyl (TEMP2) and 2,2,6,6-tetramethyl-piperidin-4-octanoyloxy-1-oxyl (TEMP8) synthesized by us, in liposomes exposed to ultraviolet A (UVA) radiation. For comparison, the UVA-absorber, 4-tert-butyl-4'-methoxydibenzoylmethane (Parsol 1789) used in many suncream formulations, was also included. The nitroxide TINO resulted extremely efficient at inhibiting aldehydic breakdown products deriving from 30 min exposure of liposomes to UVA and the protection was dose-dependent (10-100 microM). The corresponding amine HALS-1 was the least efficient while protection increased in the order: TEMP2 < Parsol 1789 < TEMP 8. HALS-1, TINO, and the two TEMPOL derivatives were also tested in a simple protein system consisting of bovine serum albumin (BSA) exposed to UVA. In this case, these compounds did not inhibit nor enhance UVA-mediated protein carbonyl formation in BSA. The differences in protection between the compounds are discussed in relation to their chemical reactivity, UVA-absorbing capacities, and their molecular structure. Overall, the results obtained envisage the potential use of nitroxide compounds as topical antioxidants.

  11. The sunburn cell in hairless mouse epidermis: quantitative studies with UV-A radiation and mono- and bifunctional psoralens

    SciTech Connect

    Young, A.R.; Magnus, I.A.

    1982-10-01

    The production of the sunburn cell by UV-A radiation and topical psoralens in hairless mouse epidermis has been studied. It has been shown that the appearance of this cell is dependent on the dose of both UV-A radiation and of the psoralen. The time-course with 8-methoxypsoralen has peak sunburn cell numbers at 28 hr postirradiation. A comparison of 2 bifunctional (8-methoxypsoralen and 5-methoxypsoralen) and 2 monofunctional (angelicin and 3-carbethoxypsoralen) psoralens showed the former are more potent. This suggests that DNA crosslink lesions may play a rle in sunburn cell production.

  12. UVA Photoactivation of Harmol Enhances Its Antifungal Activity against the Phytopathogens Penicillium digitatum and Botrytis cinerea

    PubMed Central

    Olmedo, Gabriela M.; Cerioni, Luciana; González, María M.; Cabrerizo, Franco M.; Volentini, Sabrina I.; Rapisarda, Viviana A.

    2017-01-01

    Phytopathogenic fungi responsible for post-harvest diseases on fruit and vegetables cause important economic losses. We have previously reported that harmol (1-methyl-9H-pyrido[3,4-b]indol-7-ol) is active against the causal agents of green and gray molds Penicillium digitatum and Botrytis cinerea, respectively. Here, antifungal activity of harmol was characterized in terms of pH dependency and conidial targets; also photodynamic effects of UVA irradiation on the antimicrobial action were evaluated. Harmol was able to inhibit the growth of both post-harvest fungal disease agents only in acidic conditions (pH 5), when it was found in its protonated form. Conidia treated with harmol exhibited membrane integrity loss, cell wall disruption, and cytoplasm disorganization. All these deleterious effects were more evident for B. cinerea in comparison to P. digitatum. When conidial suspensions were irradiated with UVA in the presence of harmol, antimicrobial activity against both pathogens was enhanced, compared to non-irradiated conditions. B. cinerea exhibited a high intracellular production of reactive oxygen species (ROS) when was incubated with harmol in irradiated and non-irradiated treatments. P. digitatum showed a significant increase in ROS accumulation only when treated with photoexcited harmol. The present work contributes to unravel the antifungal activity of harmol and its photoexcited counterpart against phytopathogenic conidia, focusing on ROS accumulation which could account for damage on different cellular targets. PMID:28326067

  13. UV-A fluorescence of sunscreens and possible energy transfer to skin components

    NASA Astrophysics Data System (ADS)

    Krishnan, Rajagopal; Elmets, Craig A.; Nordlund, Thomas M.

    2008-02-01

    Photophysical studies of UV-B sunscreens showed a measurable UV-A emission from padimate O (2-ethylhexyl-4-(dimethylamino)benzoate). Since recent studies associate UV-A to skin cancer induction pathways, as well as skin aging, we studied the effect of padimate O emission when applied to skin. After application of padimate O to skin the emission spectrum of skin showed a large increase in the intensity of 470 nm peak. The 470 nm emission in skin arises from a skin component, possibly collagen, which absorbs at about 360 nm, where padimate O emits. The excitation spectra of skin with padimate O measured at an emission wavelength of 468 nm show a peak at 310 nm with a broad shoulder at about 350 nm to 370 nm, which increased in intensity with time. However, the excitation spectrum of skin with octyl salicylate (another UV-B emitting sunscreen) did not show such a shoulder or increase in intensity. Thus, we attribute the presence of a shoulder in the excitation spectrum of skin and the increase in its intensity as evidence for energy transfer from padimate O to collagen. The transfer mechanism is not clear.

  14. Protein, lipid, and DNA radicals to measure skin UVA damage and modulation by melanin.

    PubMed

    Haywood, Rachel; Rogge, Fabrice; Lee, Martin

    2008-03-15

    Afro-Caribbeans have a lower incidence of skin cancer than Caucasians, but the effectiveness of melanin as a photoprotective pigment is debated. We investigated the UVA and solar irradiation of ex vivo human skin and DMPO using electron spin resonance spectroscopy, to determine whether pigmented skin is protected by melanin against free radical damage. Initial ascorbate radicals in Caucasian skin were superseded by lipid and/or protein radical adducts with isotropic (a(H)=1.8 mT) and anisotropic spectra comparable to spectra in irradiated pig fat (a(H)=1.9 mT) and BSA. DNA carbon-centered radical adducts (a(H)=2.3 mT) and a broad singlet were detected in genomic DNA/melanin but were not distinguishable in irradiated Caucasian skin. Protein and lipid radicals (n=6 in Caucasian skin) were minimal in Afro-Caribbean skin (n=4) and intermediate skin pigmentations were variable (n=3). In irradiated Afro-Caribbean skin a shoulder to the melanin radical (also in UVA-irradiated pigmented melanoma cells and genomic DNA/melanin and intrinsic to pheomelanin) was detected. In this sample group, protein (but not lipid) radical adducts decreased directly with pigmentation. ESR/spin trapping methodology has potential for screening skin susceptibility to aging and cancer-related radical damage and for measuring protection afforded by melanin, sunscreens, and antiaging creams.

  15. The respiratory chain is the cell's Achilles' heel during UVA inactivation in Escherichia coli.

    PubMed

    Bosshard, Franziska; Bucheli, Margarete; Meur, Yves; Egli, Thomas

    2010-07-01

    Solar disinfection (SODIS) is used as an effective and inexpensive tool to improve the microbiological quality of drinking water in developing countries where no other means are available. Solar UVA light is the agent that inactivates bacteria during the treatment. Damage to bacterial membranes plays a crucial role in the inactivation process. This study showed that even slightly irradiated cells (after less than 1 h of simulated sunlight) were strongly affected in their ability to maintain essential parts of their energy metabolism, in particular of the respiratory chain (activities of NADH oxidase, succinate oxidase and lactate oxidase were measured). The cells' potential to generate ATP was also strongly inhibited. Many essential enzymes of carbon metabolism (glucose-6-phosphate dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase, lactate dehydrogenase and malate dehydrogenase) and defence against oxidative stress (catalases and glutathione-disulfide reductase) were reduced in their activity during SODIS. The work suggests that damage to membrane enzymes is a likely cause of membrane dysfunction (loss of membrane potential and increased membrane permeability) during UVA irradiation. In this study, the first targets on the way to cell death were found to be the respiratory chain and F(1)F(0) ATPase.

  16. UVA-induced phenoxyl radical formation: A new cytotoxic principle in photodynamic therapy.

    PubMed

    Volkmar, Christine M; Vukadinović-Walter, Britta; Opländer, Christian; Bozkurt, Ahmet; Korth, Hans-Gert; Kirsch, Michael; Mahotka, Csaba; Pallua, Norbert; Suschek, Christoph V

    2010-09-15

    Psoralens are regularly used in therapy in combination with ultraviolet A light irradiation (PUVA) to treat skin diseases such as psoriasis, vitiligo, and mycosis fungoides. PUVA therapy is also used within the scope of extracorporeal photopheresis to treat a variety of diseases that have a suspected involvement of pathogenic T cells, including rejection of organ transplants, graft-vs-host disease, cutaneous T cell lymphoma, and autoimmune disorders. Because psoralens are the only photosensitizers used in PUVA therapies and are considered to be responsible for a number of side effects, the identification of alternative drugs is of practical interest. Here we investigated the impact of activated Trolox (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid), a hydrophilic vitamin E analog lacking the phytyl tail, as an alternative photoactivatable agent with T cell cytotoxic properties. Despite the well-known antioxidative capacity of Trolox, we found that at low UVA doses and in the presence of supraphysiological concentration of nitrite, a natural constituent of human skin, this compound selectively enhances radical-mediated cytotoxicity toward T cells but not toward human skin fibroblasts, keratinocytes, or endothelial cells. The cytotoxic mechanism comprises a reaction of Trolox with photo-decomposition products of nitrite, which leads to increased Trolox phenoxyl radical formation, increased intracellular oxidative stress, and a consecutive induction of apoptosis and necrosis in fast proliferating T cells. Thus, the identified UVA/nitrite-induced phenoxyl radical formation provides an opportunity for a new cytotoxic photodynamic therapy.

  17. Photochemical inactivation of chikungunya virus in human apheresis platelet components by amotosalen and UVA light.

    PubMed

    Tsetsarkin, Konstantin A; Sampson-Johannes, Adam; Sawyer, Lynette; Kinsey, John; Higgs, Stephen; Vanlandingham, Dana L

    2013-06-01

    Chikungunya virus (CHIKV) is a mosquito-borne alphavirus that recently re-emerged in Africa and rapidly spread into countries of the Indian Ocean basin and South-East Asia. The mean viremic blood donation risk for CHIKV on La Réunion reached 1.5% at the height of the 2005-2006 outbreaks, highlighting the need for development of safety measures to prevent transfusion-transmitted infections. We describe successful inactivation of CHIKV in human platelets and plasma using photochemical treatment with amotosalen and long wavelength UVA illumination. Platelet components in additive solution and plasma units were inoculated with two different strains of high titer CHIKV stock (6.0-8.0 logs/mL), and then treated with amotosalen and exposure to 1.0-3.0 J/cm² UVA. Based on in vitro assays of infectious virus pre- and post-treatment to identify endpoint dilutions where virus was not detectable, mean viral titers could effectively be reduced by > 6.4 ± 0.6 log₁₀ TCID₅₀/mL in platelets and ≥ 7.6 ± 1.4 logs in plasma, indicating this treatment has the capacity to prevent CHIKV transmission in human blood components collected from infected donors in or traveling from areas of CHIKV transmission.

  18. Efficacy of Punica granatum L. hydroalcoholic extract on properties of dyed hair exposed to UVA radiation.

    PubMed

    Dario, Michelli Ferrera; Pahl, Richard; de Castro, Jordana Rodrigues; de Lima, Fernando Soares; Kaneko, Telma Mary; Pinto, Claudinéia A S O; Baby, André Rolim; Velasco, Maria Valéria Robles

    2013-03-05

    The solar radiation promotes color fading of natural and dyed hair by free radical generation, which oxidize the pigments, and it has been proposed the incorporation of antioxidants in order to reduce the alterations of hair color. Due to its high content of polyphenols and tannins, which are potent antioxidants, the hydroalcoholic extract of Punica granatum L. (pomegranate) was used in this research. Hair care formulations containing pomegranate extract were applied to red dyed hair tresses, and these were exposed to UVA radiation. Non-ionic silicone emulsion presenting color protection properties were also used for comparison purpose between the results obtained with different treatments, including silicone in combination with the pomegranate extract. The pomegranate extract at 5.0% and 10.0%w/w was effective in preventing the hair color fading in 37.6% and 60.8%, respectively, but the association of hydroalcoholic extract and non-ionic silicone emulsion is not encouraged. Mechanical properties were not affected by UVA radiation, since significant differences in breaking strength were not observed. Considering the conditions which the tresses have been exposed, it was concluded that the pomegranate extract at 10.0% w/w in hair care formulations are effective in reducing color fading of red dyed hair.

  19. Effects of UVA and visible light on the photogenotoxicity of benzo[a]pyrene and pyrene.

    PubMed

    Botta, Céline; Di Giorgio, Carole; Sabatier, Anne-Sophie; De Méo, Michel

    2009-10-01

    This study investigated the role of UVA/visible light (U, 320-800 nm) and visible light (V, 400-800 nm) in the phototoxicity and photogenotoxicity of two ubiquitous polycyclic aromatic hydrocarbons (PAH): benzo[a]pyrene (BaP) and Pyrene (Pyr). These mechanisms were evaluated by the WST-1 test and the comet assay on normal human keratinocytes (NHK) and by the micronucleus test on CHO cells. The production of reactive oxygen species (ROS) was assessed through the induction of 8-oxodeoxyguanine (8-oxodG) lesions by immunofluorescence staining in NHK. Results of the WST-1 test revealed the phototoxic properties of BaP and Pyr after irradiation with U and V lights. BaP presented the highest phototoxic properties. Results of the comet assay showed that U- and V-irradiated BaP and Pyr induced increasing rates of DNA single-strand breaks in NHK, in a dose dependent manner. The tested PAH could also induce increased levels of micronuclei in CHO cells after U and V irradiations. Increasing 8-oxodG levels were detected after U and V irradiations in BaP- and Pyr-treated keratinocytes and confirmed the involvement of ROS in the photogenotoxicity of PAH. Overall, this study highlighted the existence of an alternative pathway of PAH genotoxicity that is induced by UVA and/or visible light. Visible light is suggested to photoactivate PAH by a mechanism which is mainly based on oxidative reactions.

  20. UVA Photoactivation of Harmol Enhances Its Antifungal Activity against the Phytopathogens Penicillium digitatum and Botrytis cinerea.

    PubMed

    Olmedo, Gabriela M; Cerioni, Luciana; González, María M; Cabrerizo, Franco M; Volentini, Sabrina I; Rapisarda, Viviana A

    2017-01-01

    Phytopathogenic fungi responsible for post-harvest diseases on fruit and vegetables cause important economic losses. We have previously reported that harmol (1-methyl-9H-pyrido[3,4-b]indol-7-ol) is active against the causal agents of green and gray molds Penicillium digitatum and Botrytis cinerea, respectively. Here, antifungal activity of harmol was characterized in terms of pH dependency and conidial targets; also photodynamic effects of UVA irradiation on the antimicrobial action were evaluated. Harmol was able to inhibit the growth of both post-harvest fungal disease agents only in acidic conditions (pH 5), when it was found in its protonated form. Conidia treated with harmol exhibited membrane integrity loss, cell wall disruption, and cytoplasm disorganization. All these deleterious effects were more evident for B. cinerea in comparison to P. digitatum. When conidial suspensions were irradiated with UVA in the presence of harmol, antimicrobial activity against both pathogens was enhanced, compared to non-irradiated conditions. B. cinerea exhibited a high intracellular production of reactive oxygen species (ROS) when was incubated with harmol in irradiated and non-irradiated treatments. P. digitatum showed a significant increase in ROS accumulation only when treated with photoexcited harmol. The present work contributes to unravel the antifungal activity of harmol and its photoexcited counterpart against phytopathogenic conidia, focusing on ROS accumulation which could account for damage on different cellular targets.

  1. UVA-induced ROS generation inhibition by Oenothera paradoxa defatted seeds extract and subsequent cell death in human dermal fibroblasts.

    PubMed

    Jaszewska, Edyta; Soin, Magdalena; Filipek, Agnieszka; Naruszewicz, Marek

    2013-09-05

    UVA radiation stimulates the production of reactive oxygen species (ROS), which react with lipids, proteins and other intracellular molecules leading to oxidative stress, cellular damage and ultimately cell death. There is, therefore, a growing need for substances exhibiting antioxidant activity, which may support repair mechanisms of the skin. This study evaluates the protective effect of the aqueous Oenothera paradoxa Hudziok defatted seeds extract, rich in polyphenolic compounds, against UVA (25 and 50J/cm(2))-induced changes in normal human dermal fibroblasts (NHDFs). The tested extract (0.1-10μg/ml) has decreased, in a concentration-dependent fashion, the UVA-induced release of lactate dehydrogenase (LDH) into the culture medium, the ROS production (with the use of 2',7'-dichlorodihydrofluorescein diacetate) and lipid peroxidation (utilizing redox reactions with ferrous ions) as compared to the control cells (incubated without the extract). Moreover, the extract increased the number of viable (calcein positive) cells decreasing the number of cells in late apoptosis (annexin V-FITC and propidium iodide positive). Thus our results show that O. paradoxa defatted seeds extract may be beneficial for the prevention of UVA skin damage.

  2. Five Board Games for the Language Classroom: Uvas, Montana Rusa, El Futbol, La Corrida de Verbos, Paso a Paso.

    ERIC Educational Resources Information Center

    Snyder, Barbara

    A collection of five board games for the Spanish language classroom contains gameboards, game markers, and directions for each game. It also contains general instructions for the teacher about the classroom use of board games. The games include: "Uvas," for use in vocabulary development and cultural awareness; "Montana Rusa," for general…

  3. Photoprotective potential of strawberry (Fragaria × ananassa) extract against UV-A irradiation damage on human fibroblasts.

    PubMed

    Giampieri, Francesca; Alvarez-Suarez, Josè M; Tulipani, Sara; Gonzàles-Paramàs, Ana M; Santos-Buelga, Celestino; Bompadre, Stefano; Quiles, José L; Mezzetti, Bruno; Battino, Maurizio

    2012-03-07

    Exposure to UV-A radiation is known to induce discrete lesions in DNA and the generation of free radicals that lead to a wide array of skin diseases. Strawberry (Fragaria × ananassa) contains several polyphenols with strong antioxidant and anti-inflammatory activities. Because the major representative components of strawberry are anthocyanins, these may significantly contribute to its properties. To test this hypothesis, methanolic extracts from the Sveva cultivar were analyzed for anthocyanin content and for their ability to protect human dermal fibroblasts against UV-A radiation, as assayed using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenytetrazolium bromide and Comet assays. Five anthocyanin pigments were identified using high-performance liquid chromatography-diode array detection-electrospray ionization/mass spectrometry. Moreover, the strawberry extract showed a photoprotective activity in fibroblasts exposed to UV-A radiation, increasing cellular viability, and diminishing DNA damage, as compared to control cells. Overall, our data show that strawberry contains compounds that confer photoprotective activity in human cell lines and may protect skin against the adverse effects of UV-A radiation.

  4. Astronomía en la cultura

    NASA Astrophysics Data System (ADS)

    López, A.; Giménez Benitez, S.; Fernández, L.

    La Astronomía en la Cultura es el estudio interdisciplinario a nivel global de la astronomía prehistórica, antigua y tradicional, en el marco de su contexto cultural. Esta disciplina abarca cualquier tipo de estudios o líneas de investigación en que se relacione a la astronomía con las ciencias humanas o sociales. En ella se incluyen tanto fuentes escritas, relatos orales como fuentes arqueológicas, abarcando entre otros, los siguientes temas: calendarios, observación práctica, cultos y mitos, representación simbólica de eventos, conceptos y objetos astronómicos, orientación astronómica de tumbas, templos, santuarios y centros urbanos, cosmología tradicional y la aplicación ceremonial de tradiciones astronómicas, la propia historia de la astronomía y la etnoastronomía (Krupp, 1989) (Iwaniszewski, 1994). En nuestro trabajo abordamos la historia y situación actual de esta disciplina, sus métodos y sus relaciones con otras áreas de investigación.

  5. Inhibition of UVA-mediated melanogenesis by ascorbic acid through modulation of antioxidant defense and nitric oxide system.

    PubMed

    Panich, Uraiwan; Tangsupa-a-nan, Vanida; Onkoksoong, Tasanee; Kongtaphan, Kamolratana; Kasetsinsombat, Kanda; Akarasereenont, Pravit; Wongkajornsilp, Adisak

    2011-05-01

    Ascorbic acid (AA) has been well known as a skin whitening agent, although attempts have been made to evaluate its protective role against ultraviolet (UV)-induced skin hyperpigmentation or increased melanin production. While melanogenesis is a defense mechanism of the skin against UV irradiation, melanin overproduction may also contribute to melanoma initiation. UVA might play a role in melanogenesis through promoting oxidative stress, which occurs as the result of increased formation of oxidants and/or reactive nitrogen species (RNS) including nitric oxide (NO). Therefore, we investigated the antimelanogenic effect of AA (7.5-120 μM) in association with its inhibitory effect on UVA-induced oxidant formation, NO production through endothelial and inducible NO synthases (eNOS and iNOS) activation and impairment of antioxidant defense using G361 human melanoma cells. Our study demonstrated a comparable ability of AA with that of kojic acid, a well-known tyrosinase inhibitor in inhibiting mushroom tyrosinase. Melanin content was reduced by AA, but neither tyrosinase activity nor mRNA levels were reduced by AA at non-cytotoxic concentrations in UVA-irradiated G361 cells. AA was shown to inhibit UVA-mediated catalase (CAT) inactivation, glutathione (GSH) depletion, oxidant formation and NO production through suppression of eNOS and iNOS mRNA. We report herein that AA can protect against UVA-dependent melanogenesis possibly through the improvement of antioxidant defense capacity and inhibition of NO production through down-regulation of eNOS and iNOS mRNA.

  6. Reduced hydroperoxidase (HPI and HPII) activity in the Deltafur mutant contributes to increased sensitivity to UVA radiation in Escherichia coli.

    PubMed

    Hoerter, James D; Arnold, Alan A; Ward, Christopher S; Sauer, Michael; Johnson, Steve; Fleming, Todd; Eisenstark, Abraham

    2005-05-13

    In Escherichia coli, Deltafur (ferric uptake regulator) mutants are hypersensitive to various oxidative agents, including UVA radiation (400-315 nm). Studies suggest that UVA radiation mediates its biological effects on bacteria via oxidative mechanisms that lead to reactive oxygen species, including the superoxide anion radical (O2.-), hydroxyl radical (HO.), hydrogen peroxide (H2O2) and singlet oxygen (1O2). There is accumulating evidence that Fur may play an important role in the defense against UVA radiation. In addition to regulating almost all genes directly involved in iron acquisition, Fur also regulates the expression of manganese and iron superoxide dismutase (MnSOD, FeSOD), key enzymes in the defense against oxygen toxicity in E. coli. In Deltafur mutants, there is a complete absence of FeSOD. Previous results suggest that the native iron chelating agent, enterobactin, which exists in increased levels in Deltafur mutants, is an endogenous chromophore for UVA, releasing Fe2+ into the cytoplasm to catalyze the production of highly reactive hydroxyl radicals. We now report that the hypersensitivity of Deltafur mutants to UVA irradiation is associated with reduced hydroperoxidase I (HPI) and hydroperoxidase II (HPII) activity, and is associated with a decrease in the transcription of katE and katG genes. The observed decrease in HPII activity in Deltafur mutants is also associated with reduced rpoS gene transcription. This study provides additional evidence that the Fur gene product, in addition to its known regulatory effect on the expression of SOD and iron uptake mechanisms, also regulates HPI and HPII activity levels in E. coli. An H2O2-inducible antioxidant defense system leading to an increase in HPI activity, is unaltered in Deltafur mutants.

  7. Towards a high performing UV-A sensor based on Silicon Carbide and hydrogenated Silicon Nitride absorbing layers

    NASA Astrophysics Data System (ADS)

    Mazzillo, M.; Sciuto, A.; Mannino, G.; Renna, L.; Costa, N.; Badalà, P.

    2016-10-01

    Exposure to ultraviolet (UV) radiation is a major risk factor for most skin cancers. The sun is our primary natural source of UV radiation. The strength of the sun's ultraviolet radiation is expressed as Solar UV Index (UVI). UV-A (320-400 nm) and UV-B (290-320 nm) rays mostly contribute to UVI. UV-B is typically the most destructive form of UV radiation because it has enough energy to cause photochemical damage to cellular DNA. Also overexposure to UV-A rays, although these are less energetic than UV-B photons, has been associated with toughening of the skin, suppression of the immune system, and cataract formation. The use of preventive measures to decrease sunlight UV radiation absorption is fundamental to reduce acute and irreversible health diseases to skin, eyes and immune system. In this perspective UV sensors able to monitor in a monolithic and compact chip the UV Index and relative UV-A and UV-B components of solar spectrum can play a relevant role for prevention, especially in view of the integration of these detectors in close at hand portable devices. Here we present the preliminary results obtained on our UV-A sensor technology based on the use of hydrogenated Silicon Nitride (SiN:H) thin passivating layers deposited on the surface of thin continuous metal film Ni2Si/4H-SiC Schottky detectors, already used for UV-Index monitoring. The first UV-A detector prototypes exhibit a very low leakage current density of about 0.2 pA/mm2 and a peak responsivity value of 0.027 A/W at 330 nm, both measured at 0V bias.

  8. The PARP inhibitor PJ-34 sensitizes cells to UVA-induced phototoxicity by a PARP independent mechanism.

    PubMed

    Lakatos, Petra; Hegedűs, Csaba; Salazar Ayestarán, Nerea; Juarranz, Ángeles; Kövér, Katalin E; Szabó, Éva; Virág, László

    2016-08-01

    A combination of a photosensitizer with light of matching wavelength is a common treatment modality in various diseases including psoriasis, atopic dermatitis and tumors. DNA damage and production of reactive oxygen intermediates may impact pathological cellular functions and viability. Here we set out to investigate the role of the nuclear DNA nick sensor enzyme poly(ADP-ribose) polymerase 1 in photochemical treatment (PCT)-induced tumor cell killing. We found that silencing PARP-1 or inhibition of its enzymatic activity with Veliparib had no significant effect on the viability of A431 cells exposed to 8-methoxypsoralen (8-MOP) and UVA (2.5J/cm(2)) indicating that PARP-1 is not likely to be a key player in either cell survival or cell death of PCT-exposed cells. Interestingly, however, another commonly used PARP inhibitor PJ-34 proved to be a photosensitizer with potency equal to 8-MOP. Irradiation of PJ-34 with UVA caused changes both in the UV absorption and in the 1H NMR spectra of the compound with the latter suggesting UVA-induced formation of tautomeric forms of the compound. Characterization of the photosensitizing effect revealed that PJ-34+UVA triggers overproduction of reactive oxygen species, induces DNA damage, activation of caspase 3 and caspase 8 and internucleosomal DNA fragmentation. Cell death in this model could not be prevented by antioxidants (ascorbic acid, trolox, glutathione, gallotannin or cell permeable superoxide dismutase or catalase) but could be suppressed by inhibitors of caspase-3 and -8. In conclusion, PJ-34 is a photosensitizer and PJ-34+UVA causes DNA damage and caspase-mediated cell death independently of PARP-1 inhibition.

  9. Response and Defense Mechanisms of Taxus chinensis Leaves Under UV-A Radiation are Revealed Using Comparative Proteomics and Metabolomics Analyses.

    PubMed

    Zheng, Wen; Komatsu, Setsuko; Zhu, Wei; Zhang, Lin; Li, Ximin; Cui, Lei; Tian, Jingkui

    2016-09-01

    Taxus chinensis var. mairei is a species endemic to south-eastern China and one of the natural sources for the anticancer medicine paclitaxel. To investigate the molecular response and defense mechanisms of T. chinensis leaves to enhanced ultraviolet-A (UV-A) radiation, gel-free/label-free and gel-based proteomics and gas chromatography-mass spectrometry (GC-MS) analyses were performed. The transmission electron microscopy results indicated damage to the chloroplast under UV-A radiation. Proteomics analyses in leaves and chloroplasts showed that photosynthesis-, glycolysis-, secondary metabolism-, stress-, and protein synthesis-, degradation- and activation-related systems were mainly changed under UV-A radiation. Forty-seven PSII proteins and six PSI proteins were identified as being changed in leaves and chloroplasts under UV-A treatment. This indicated that PSII was more sensitive to UV-A than PSI as the target of UV-A light. Enhanced glycolysis, with four glycolysis-related key enzymes increased, provided precursors for secondary metabolism. The 1-deoxy-d-xylulose-5-phosphate reductoisomerase and 4-hydroxy-3-methylbut-2-enyl diphosphate reductase were identified as being significantly increased during UV-A radiation, which resulted in paclitaxel enhancement. Additionally, mRNA expression levels of genes involved in the paclitaxel biosynthetic pathway indicated a down-regulation under UV-A irradiation and up-regulation in dark incubation. These results reveal that a short-term high dose of UV-A radiation could stimulate the plant stress defense system and paclitaxel production.

  10. NASA-UVA Light Aerospace Alloy and Structures Technology Program (LA2ST)

    NASA Technical Reports Server (NTRS)

    Scully, John R.; Shiflet, Gary J.; Stoner, Glenn E.; Wert, John A.

    1996-01-01

    The NASA-UVA Light Aerospace Alloy and Structures Technology (LA2ST) Program was initiated in 1986 and continues with a high level of activity. The objective of the LA2ST Program is to conduct interdisciplinary graduate student research on the performance of next generation, light-weight aerospace alloys, composites and thermal gradient structures in collaboration with NASA-Langley researchers. Specific technical objectives are presented for each research project. We generally aim to produce relevant data and basic understanding of material mechanical response, environmental/corrosion behavior, and microstructure; new monolithic and composite alloys; advanced processing methods; new solid and fluid mechanics analyses; measurement and modeling advances; and a pool of educated graduate students for aerospace technologies. Three research areas are being actively investigated, including: (1) Mechanical and environmental degradation mechanisms in advanced light metals, (2) Aerospace materials science, and (3) Mechanics of materials for light aerospace structures.

  11. Detecting free radicals in sunscreens exposed to UVA radiation using chemiluminescence.

    PubMed

    Millington, Keith R; Osmond, Megan J; McCall, Maxine J

    2014-04-05

    One of the current concerns with the application of nanoparticles in sunscreens, and in particular nano-TiO2 and ZnO, is their potential to photogenerate free radicals and reactive oxygen species (ROS) when they absorb ultraviolet wavelengths from sunlight. Free radicals and ROS are known to be associated with UV-induced skin damage and oxidative stress, from which sunscreens are expected to offer significant protection. Here we describe a simple method, based on chemiluminescence emission, for detecting free radicals generated in commercial sunscreens alone, and when applied to various substrates, following exposure to UVA (320-400nm) radiation. This photo-induced chemiluminescence (PICL) technique could be used to optimise sunscreen formulations so as to minimise free radical photogeneration during exposure to sunlight.

  12. UVA-UVB Photoprotective Activity of Topical Formulations Containing Morinda citrifolia Extract

    PubMed Central

    Serafini, Mairim Russo; Detoni, Cassia Britto; Menezes, Paula dos Passos; Pereira Filho, Rose Nely; Fortes, Vanessa Silveira; Vieira, Maria José Fonseca; Guterres, Sílvia Stanisçuaski; de Albuquerque Junior, Ricardo Luiz Cavalcanti; Araújo, Adriano Antunes de Souza

    2014-01-01

    Exposure to solar radiation, particularly its ultraviolet (UV) component, has a variety of harmful effects on human health. Some of these effects include sunburn cell formations, basal and squamous cell cancers, melanoma, cataracts, photoaging of the skin, and immune suppression. The beneficial photoprotective effects of topical formulations with the extract, Morinda citrifolia, have not been investigated. This present study aims to investigate the potential benefits of M. citrifolia topical application on the dorsal skin of mice, exposed to UVA-UVB light. Using 7 days of treatment, [before (baseline values) and 20 h after UV exposure], the thickness, skin barrier damage (TEWL), erythema, and histological alterations were evaluated. The results showed that the formulations containing the extract protected the skin against UV-induced damage. PMID:25133171

  13. Differences in the immunologic reactivity of mice treated with UVB or methoxsalen plus UVA radiation

    SciTech Connect

    Kripke, M.L.; Morison, W.L.; Parrish, J.A.

    1981-06-01

    Skin tumors induced in mice by chronic exposure to UVB radiation are often highly antigenic and regress when transplanted into normal syngeneic animals, but grow progressively in immunosuppressed mice. Exposure of mice to subtumorigenic doses of UVB radiation can abolish this immunologic rejection phenomenon. In this study, we have investigated the effects of treatment with 8-methoxypsoralen plus UVA radiation (PUVA) on the rejection of antigenic UVB-induced tumors. PUVA treatment, with either topical or systemic administration of the psoralen, did not alter the normal process of rejection of UVB-induced tumors. Mice treated with both minimally and markedly phototoxic doses of PUVA rejected tumors with a frequency similar to that seen in untreated animals, although these tumors grew progressively in UVB-irradiated mice. These results indicate that the effects of PUVA treatment differ from those of UVB irradiation in that PUVA treatment does not alter the immunologic rejection of UVB-induced tumors.

  14. NASA-UVA light aerospace alloy and structures technology program (LA2ST)

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.; Starke, Edger A., Jr.

    1996-01-01

    This progress report covers achievements made between January 1 and June 30, 1966 on the NASA-UVA Light Aerospace Alloy and Structures Technology (LA2ST) Program. The objective of the LA2ST Program is to conduct interdisciplinary graduate student research on the performance of next generation, light-weight aerospace alloys, composites and thermal gradient structures in collaboration with NASA-Langley researchers. Specific technical objectives are presented for each research project. . The accomplishments presented in this report are: (1) Mechanical and Environmental Degradation Mechanisms in Advanced Light Metals, (2) Aerospace Materials Science, and (3) Mechanics of Materials for Light Aerospace Structures. Collective accomplishments between January and June of 1996 include: 4 journal or proceedings publications, 1 NASA progress report, 4 presentations at national technical meetings, and 2 PhD dissertations published.

  15. Protection against UVA-induced photooxidative damage in mammalian cell lines expressing increased levels of metallothionein

    SciTech Connect

    Dudek, E.J. Illinois Inst. of Tech., Chicago, IL . Dept. of Biology); Peak, J.G.; Peak, M.J. ); Roth, R.M. . Dept. of Biology)

    1990-01-01

    Metallothionein (MT) is an endogenous low molecular weight protein that is inducible in a variety of eukaryotic cells and has the ability to selectivity bind heavy metal ions such as zinc and the cadmium. Although the exact physiological role of MT is still not understood, there is strong evidence that MT is involved in providing cellular resistance against the damaging effects of heavy metals and in the regulation of intracellular zinc and copper. Recently, it has been demonstrated that MT can scavenge radiation-induced reactive oxygen intermediates in vitro, specifically hydroxyl and superoxide radicals, and because of these observations it has been suggested that MT may provide protection against radiation-induced oxidative stress in vivo. Cell lines expressing increased levels of MT have demonstrated resistance to ionizing radiation, to ultraviolet radiation, and also to various DNA damaging agents including melphalan and cis-diaminedichloroplatinum. It is therefore important to gain some insight into the relationship between cellular MT content and cellular resistance to radiation and other DNA damaging agents. In this study we investigated the role of MT in providing protection against monochromatic 365-nm UVA radiation, which is known to generate intracellular reactive oxygen species that are involved in both DNA damage and cell killing. For this purpose, we used zinc acetate, a potent inducer of MT, to elevate MT levels in V79 Chinese hamster fibroblasts prior to UVA exposure and determined cell survival for uninduced and induced cultures. In order to eliminate any zinc effects other than MT induction, we also isolated and characterized cadmium chloride-resistant clones of V79 cells that have increased steady-state levels of both MT mRNA and protein, and we examined their survival characteristics against 365-nm radiation in the absence of zinc acetate. 14 refs., 3 figs.

  16. Synthesis and Photoirradiation of Isomeric Ethylchrysenes by UVA Light Leading to Lipid Peroxidation

    PubMed Central

    Chen, Hui-Chan; Xia, Qingsu; Cherng, Shu-Hui; Chen, Shoujun; Lai, Ching-Cheng; Yu, Hongtao; Fu, Peter P.

    2007-01-01

    Polycyclic aromatic hydrocarbons (PAHs) are widespread genotoxic environmental pollutants. We have recently demonstrated that photoirradiation of PAHs leads to cytotoxicity, DNA damage, and induction of lipid peroxidation. In this paper we report the synthesis of all the six isomeric ethylchrysenes and the study of light-induced lipid peroxidation by these ethylchrysenes. 5-Ethylchrysene was synthesized by reaction of 5-keto-5,6,6a,7,8,9,10,10a-octahydrochrysene with CH3CH2MgBr followed by dehydration catalyzed by p-toluenesulfonic acid and dehydrogenation with DDQ in benzene. 1- and 4-Ethylchrysenes were similarly prepared by reaction of 1-keto-1,2,3,4,5,6-hexahydrochrysene and 4-keto-1,2,3,4-tetrahydrochrysenes, respectively with CH3CH2MgBr followed by dehydration and dehydrogenation. Direct acetylation of chrysene followed by Wolff-Kishner or Clemmensen reduction resulted in the formation of 2-, 3-, and 6-ethylchrysenes in 4%, 16%, and 43% yields, respectively. Photoirradiation of these compounds with 7 and 21 J/cm2 UVA light in the presence of methyl linoleate all resulted in lipid peroxidation. For comparison, photoirradiation of 4-methylchrysene and 5-methylchrysene was similarly conducted. For irradiation at a UVA light dose of 21 J/cm2, the level of induced lipid peroxidation is in the order 4-methylchrysene = 5-methylchrysene = 5-ethylchrysene = 4-ethylchrysene = chrysene > 1-ethylchrysene = 2-ethylchrysene > 3-ethylchrysene > 6-ethylchrysene. Compared with chrysene, these results indicate that the ethyl group at C4 or C5 position either slightly enhances or has no effect on the light-induced lipid peroxidation, while at C1-, C2-, C3-, or C6 position reduces light-induced lipid peroxidation. PMID:17617678

  17. UVA mediated synthesis of gold nanoparticles in pharmaceutical-grade heparin sodium solutions

    NASA Astrophysics Data System (ADS)

    Rodríguez-Torres, M. Del P.; Diaz-Torres, L. A.; Olmos-López, M.; Salas, P.; Gutiérrez, Clara

    2013-09-01

    A photochemical-based method in which UVA light (λ=366 nm) is used for synthesizing gold nanoparticles is presented by irradiating gold (III) chloride hydrate (HAuCl4) in the presence of pharmaceutical-grade heparin sodium (PGHEP) as a reducing and stabilizing agent in aqueous solution. Different HAuCl4 to PGHEP concentration ratios were exposed to UVA for up to seven hours. The as-synthesized nanoparticles were characterized by UV-VIS and Raman spectroscopy, transmission electron microscopy (TEM), and pH measurements. The synthesized AuNPs present spherical as well as anisotropic shapes, such as oval, triangular, hexagonal sheets, rods, and some other faceted forms, with dimensions ranging from 20 nm to 300 nm. All obtained products show good temporal stability in solution. Surface plasmons differ when varying HAuCl4 to PGHEP concentration ratio. The obtained samples exhibit two absorption peaks, one in the region between 500-600 nm, and another one in the near-IR between 900-1200 nm; both peaks shift to longer wavelengths and increase their absorption intensity as the HAuCl4 to PGHEP concentration ratio increase. TEM images show the change in nanoparticles yield as well as the shape and sizes change depending on HAuCl4 to PGHEP concentration ratio variation. Ph measurements suggest that acidic media promote anisotropic nanoparticle formation. Raman spectroscopy was used to find out which heparin sodium main groups attached to the nanoparticles surface, and in what amount. In summary, it is found that when modifying the reactants concentrations and keeping the UV exposition time as the only fixed parameter, different nanoparticles with distinctive characteristics can be attained.

  18. A role for Nrf2 in UVA-mediated heme oxygenase induction and protection from membrane damage in human skin fibroblasts

    NASA Astrophysics Data System (ADS)

    Li, Haibin; Li, Linhao; Deng, Linhong; Singh, Gurinder; Tyrrell, Rex M.; Zhong, J. Li

    2010-11-01

    Our previous study has shown that Ultraviolet-A (UVA) irradiation induces heme oxygenase 1 (HO-1) expression in cultured human primary skin fibroblasts FEK4. In the present study, we demonstrate a coordinated induction of HO-1 and NF-E2-related factor 2 (Nrf2) following UVA irradiation or hemin treatment. The induction of HO-1 by either UVA irradiation or hemin treatment was largely abolished by down-regulation of Nrf2 with its targeted short interfering RNA (siNrf2). The study further reveals that knockdown of Nrf2 protein increased UVA-induced cell death measured by MTS assay. These findings together indicate that Nrf2-mediated induction of HO-1 expression may provide a cytoprotection for human skin cells from oxidative damage.

  19. Adaptive cellular protection against UVA-1-induced lipid peroxidation in human dermal fibroblasts shows donor-to-donor variability and is glutathione dependent.

    PubMed

    Schneider, Lars Alexander; Dissemond, Joachim; Brenneisen, Peter; Hainzl, Adelheid; Briviba, Karlis; Wlaschek, Meinhard; Scharffetter-Kochanek, Karin

    2006-01-01

    Photo-oxidative stress and subsequent lipid peroxidation (LPO) is one of the major mechanisms of UVA-related skin pathology. The skin's protection system against photo-oxidative stress involves low molecular scavengers as well as highly specialised antioxidant enzymes like glutathione peroxidase (GPX). Against repetitive UVA-1 exposures in vitro it is partly adaptive, as recent studies have shown exemplarily for antioxidant enzymes. We now investigated in vitro by repetitively irradiating human dermal fibroblasts with UVA-1 whether this adaptive response might reflect itself in reduced cellular membrane damage, that is, LPO. Our experiments show that the degree of cellular protection against LPO and the adaptive potential of the cells against a repetitive UVA-1 exposure varies from donor-to-donor and depends highly on glutathione.

  20. Prevention of polymorphic light eruption with a sunscreen of very high protection level against UVB and UVA radiation under standardized photodiagnostic conditions.

    PubMed

    Schleyer, Verena; Weber, Oliver; Yazdi, Amir; Benedix, Frauke; Dietz, Klaus; Röcken, Martin; Berneburg, Mark

    2008-01-01

    Polymorphic light eruption (PLE), with an overall prevalence of 10-20%, is mainly provoked by ultraviolet A (UVA) (320-400 nm) and to a lesser degree by UVB (280-320 nm). The most effective prophylaxis of PLE, application of UV protection clothing, is not feasible for all sun-exposed areas of the skin and UV-hardening is time-consuming and may be associated with side-effects. Most sunscreens protect predominantly against UVB and therefore fail to prevent PLE. The protection level of potent UVA-protective filters remains unresolved. This single-centre, open, placebo-controlled, intra-individual, comparative study, analysed the efficacy of a sunscreen of very high protection level against UVB and UVA, containing methylene bis-benzotriazolyl tetramethylbutylphenol (Tinosorb M), bis-ethylhexyloxyphenol methoxyphenyl triazine (Tinosorb S) and butyl methoxydibenzoylmethane as UVA absorbing filters, in the prevention of PLE under standardized photodiagnostic conditions. After determination of the minimal erythema dose at day 0, photoprovocation was performed in 12 patients with a clinical history of PLE, on days 1, 2 and 3 with 100 J/cm2 UVA and variable doses of UVB, starting with the 1.5-fold minimal erythema dose of UVB. Prior to irradiation, placebo was applied to the right and sunscreen to the left dorsal forearm under COLIPA (European Cosmetic, Toiletry and Perfumery Association) conditions. In 10 patients PLE could be provoked at the placebo site, with positive reactions in 90% of the UVA, 40% of the UVB and 90% of the UVA/UVB irradiated fields. At the site with the active treatment none of these patients developed PLE. These data demonstrate that a sunscreen with effective filters against UVA and UVB can successfully prevent the development of PLE. Further studies are needed to examine whether regular application of sunscreen under everyday conditions, especially in doses less than the tested COLIPA-norm, could be an equivalent alternative to UV-hardening therapy.

  1. The involvement of heat shock protein and cytochrome P450 genes in response to UV-A exposure in the beetle Tribolium castaneum.

    PubMed

    Sang, Wen; Ma, Wei-Hua; Qiu, Lin; Zhu, Zhi-Hui; Lei, Chao-Liang

    2012-06-01

    Sunlight is an important environmental factor that affects all living organisms on Earth. Ultraviolet A (UV-A) is one of the many frequency bands found in sunlight. Many animals use UV-A to attain visual cues, for example, in foraging and mate selection. However, UV-A can also induce damage, such as oxidative stress, DNA lesions and apoptosis. In the present study, we investigated the effects of UV-A on the survival, fecundity and expression profiles of several stress-responsive genes belonging to the heat shock protein (Hsp) and the cytochrome CYP6BQ families from the adult red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae). The results showed that short-term UV-A exposure (365 nm, <4h) did not influence the survival or fecundity of the beetles; however, Hsp27, Hsp68, Hsp83, CYP6BQ4 and CYP6BQ8 mRNA levels significantly increased during the first 2h of UV-A exposure. Among them, Hsp68 was the most highly up-regulated, increasing by 8.9-fold. These results indicate that these genes may participate in the defense against harmful UV-A radiation. In addition, we investigated the potential transcription factor binding motifs (TFBMs) in the promoter sequences of genes induced in similar pattern from the Hsp and P450 gene families; the results indicated that, these motifs are highly homologous to environmental stress transcription factor binding sites in mammals. Our experiments revealed that UV-A irradiation could influence the expression profile of stress-responsive genes, such as Hsps and P450s, which have universal TFBMs, and that these genes may be involved in reducing the ecological challenges posed by irradiation.

  2. Norovirus and MS2 inactivation kinetics of UV-A and UV-B with and without TiO2.

    PubMed

    Lee, Jung Eun; Ko, GwangPyo

    2013-10-01

    Germicidal ultraviolet, such as 254-nm UV-C, is a common method of disinfection of pathogenic enteric viruses. However, the disinfection efficacies of UV-A or -B in terms of inactivating waterborne viruses such as norovirus have not been characterized. We evaluated the inactivation kinetics of MS2 bacteriophage and murine norovirus (MNV), a surrogate of human norovirus (NoV), by UV-A and -B. In addition to UV disinfection, we further investigated whether the presence of TiO2 could enhance the virus inactivation kinetics of UV-A and -B. Both MS2 and MNV were highly resistant to UV-A. However, the addition of TiO2 enhanced the efficacy of UV-A for inactivating these viruses. UV-A dose of 1379 mJ/cm(2) resulted in a 4 log10 reduction. In comparison, UV-B alone effectively inactivated both MS2 and MNV, as evidenced by the 4 log10 reduction by 367 mJ/cm(2) of UV-B. The addition of TiO2 increased the inactivation of MS2; however, it did not significantly increase the efficacy of UV-B disinfection for inactivating MNV. When these treatments were applied to field water such as groundwater, the results were generally consistent with the laboratory findings. Our results clearly indicated that UV-B is useful for the disinfection of waterborne norovirus. However, MNV was quite resistant to UV-A, and UV-A effectively inactivated the tested viruses only when used in combination with TiO2.

  3. Modulation of gene expression by the oxidative stress generated in human skin cells by UVA radiation and the restoration of redox homeostasis.

    PubMed

    Tyrrell, Rex M

    2012-01-01

    UVA radiation generates a significant oxidative stress in skin cells which is further enhanced by the release of the pro-oxidant catalysts iron and heme, and exacerbated by UVA-mediated destruction of cellular reducing equivalents and the antioxidant enzyme catalase. An important consequence of this altered redox state is the generation of oxidized membrane components in the form of 4-hydroxynonenal, ceramides and oxidized phospholipids, all of which are potent signalling molecules which lead to modulation of the expression of many genes. Transcription factors (such as nuclear factor kappa-light-chain-enhancer of activated B cells) and several genes (e.g. interleukins, intercellular adhesion molecule and 1, hemeoxygenase 1) involved in the inflammatory response are dramatically modified by UVA. Levels of both antioxidant and pro-oxidant proteins, including manganese-dependent superoxide dismutase, glutathione peroxidase, hemeoxygenase 1, NADPH oxidase, ferritin, and methionine-S-sulfoxidereductase, are increased by UVA treatment and following moderate dose levels these will contribute to either the restoration or a further perturbation of redox homeostasis. Finally, UVA induces a whole set of matrix metalloproteinases and proteases, primarily in cells of dermal origin, which can contribute to the long-term consequences of UVA exposure of skin.

  4. Astaxanthin, canthaxanthin and beta-carotene differently affect UVA-induced oxidative damage and expression of oxidative stress-responsive enzymes.

    PubMed

    Camera, Emanuela; Mastrofrancesco, Arianna; Fabbri, Claudia; Daubrawa, Felicitas; Picardo, Mauro; Sies, Helmut; Stahl, Wilhelm

    2009-03-01

    Carotenoids are used for systemic photoprotection in humans. Regarding mechanisms underlying photoprotective effects of carotenoids, here we compared the modulation of UVA-related injury by carotenoids. Human dermal fibroblasts (HDF) were exposed to moderate doses of UVA, which stimulated apoptosis, increased levels of reactive oxygen species and thiobarbituric acid reactive substances, decreased antioxidant enzymes activities, promoted membrane perturbation, and induced the expression of heme oxygenase-1 (HO-1). The carotenoids astaxanthin (AX), canthaxanthin (CX) and beta-carotene (betaC) were delivered to HDF 24 h before exposure to UVA. Astaxanthin exhibited a pronounced photoprotective effect and counteracted all of the above-mentioned UVA-induced alterations to a significant extent. beta-Carotene only partially prevented the UVA-induced decline of catalase and superoxide dismutase activities, but it increased membrane damage and stimulated HO-1 expression. Moreover, betaC dose-dependently induced caspase-3 activity following UVA exposure. In contrast, CX had no effect on oxidative damage, except for HO-1 expression, which was augmented. Uptake of AX by fibroblasts was higher than that of the other two carotenoids. The photostability of the three compounds in fibroblasts was AX > CX > betaC. The data indicate that the oxo-carotenoid AX has a superior preventive effect towards photo-oxidative changes in cell culture.

  5. Ultraviolet A irradiation induces NF-E2-related factor 2 activation in dermal fibroblasts: protective role in UVA-induced apoptosis.

    PubMed

    Hirota, Ayako; Kawachi, Yasuhiro; Itoh, Ken; Nakamura, Yasuhiro; Xu, Xuezhu; Banno, Tomohiro; Takahashi, Takenori; Yamamoto, Masayuki; Otsuka, Fujio

    2005-04-01

    Ultraviolet (UV) radiation is one of the most important environmental factors involved in the pathogenesis of skin aging and cancer. Many harmful effects of UV radiation are associated with the generation of reactive oxygen species, and cellular antioxidants act to prevent the occurrence and reduce the severity of UV-induced skin disorders. Transcription factor NF-E2-related Factor 2 (Nrf2) and its cytoplasmic anchor protein Kelch-like-ECH-associated protein 1 (Keap1) are central regulators of the cellular antioxidant response. In this study, we investigated the effects of UV irradiation on the activation of Nrf2 in dermal fibroblasts. We found that UVA irradiation, but not UVB, causes nuclear translocation and accumulation of Nrf2 by a factor of 6.5 as compared with unirradiated controls. The nuclear accumulation of Nrf2 induced by UVA was enhanced by the photosensitizer hematoporphyrin. To evaluate the protective role of Nrf2 against UVA radiation, we examined UVA-induced apoptosis using dermal fibroblasts derived from nrf2 or keap1 gene knockout mice. Whereas disruption of nrf2 increased the number of apoptotic cells following UVA irradiation by 1.7-fold, disruption of keap1 decreased the apoptotic cell number by half as compared with wild-type controls. These findings thus demonstrate that the Nrf2-Keap1 pathway plays an important role in the protection of the skin against UVA irradiation.

  6. Effects of in vitro UVA irradiation and PUVA treatment on membrane fatty acids and activities of antioxidant enzymes in human keratinocytes

    SciTech Connect

    Punnonen, K.; Jansen, C.T.; Puntala, A.; Ahotupa, M. )

    1991-02-01

    Human Keratinocytes (NCTC 2544) in culture were exposed to either plain ultraviolet A (UVA) irradiation or to 8-methoxypsoralen plus UVA (PUVA) treatment. Lipid peroxidation, activities of antioxidant enzymes, and percentage amounts of 14C-arachidonic acid in various cellular lipid subclasses and in the culture medium were measured. Both UVA irradiation and PUVA treatment induced significant changes in the distribution of arachidonic acid and increased the liberation of arachidonic acid from membrane phospholipids. At 24 h after either UVA irradiation or PUVA treatment the formation of thiobarbituric acid reactive material was significantly increased, whereas the amount of conjugated dienes was unaffected. The activities of the antioxidant enzymes, catalase and superoxide dismutase, were already significantly decreased at 0.5 h after UVA irradiation or PUVA treatment. The enzyme activities were partially restored during the following 24 h incubation. From the present study, we suggest that in keratinocytes both plain UVA irradiation and PUVA treatment induce changes in the distribution of membrane fatty acids and cause an impairment in the enzymic defense system against oxidative stress.

  7. Effect of supplemental UV-B and UV-A on phenolic accumulation, growth and photosynthesis in barley and soybean seedlings

    SciTech Connect

    Liu, Lan; Gitz, D.C. III; Huerta, A.J.; McClure, J.W. )

    1990-05-01

    Barley (Atlas 68) and soybeans (Williams, Pella and Hobbit) were grown under 260 {mu}E m{sup {minus}2} s{sup {minus}1} cool-white fluorescent light plus: (1) no supplemental illumination, (2) UV-B from Phillips FS40 lamps to simulate 30% O{sub 3} depletion at 40{degree}N, or (3) UV-A from Mylar-filtered FS40 lamps. In barley primary leaves, neither UV-A nor UV-B had any effect on the accumulation of flavonoids or ferulic acid in the epidermis. In contrast, in barley mesophyll flavonoids were increased ca. 40% by UV-A and ca. 80% by UV-B and mesophyll ferulic acid increased ca. 10 fold under either UV-A or UV-B. In soybean primary leaves UV-A had no effect on flavonoid (all were epidermal) accumulation in any variety, but UV-B increased flavonoid accumulation ca. 20% in Williams, 100% in Pella and almost 10-fold in Hobbit. UV-A and UV-B effects on growth rates and selected photosynthetic parameters will be presented.

  8. A broad-spectrum sunscreen prevents UVA radiation-induced gene expression in reconstructed skin in vitro and in human skin in vivo.

    PubMed

    Marionnet, Claire; Grether-Beck, Susanne; Seité, Sophie; Marini, Alessandra; Jaenicke, Thomas; Lejeune, François; Bastien, Philippe; Rougier, André; Bernerd, Françoise; Krutmann, Jean

    2011-06-01

    The efficacy of sunscreens to protect against ultraviolet (UV) A radiation is usually assessed by measuring erythema formation and pigmentation. The biological relevance of these endpoints for UVA-induced skin damage, however, is not known. We therefore carried out two complementary studies to determine UVA protection provided by a broad-spectrum sunscreen product at a molecular level by studying UVA radiation-induced gene expression. One study was performed on human reconstructed skin in vitro with a semi-global gene expression analysis of 227 genes in fibroblasts and 244 in keratinocytes. The second one was conducted in vivo in human volunteers and focused on genes involved in oxidative stress response and photo-ageing (haeme oxygenase-1, superoxide dismutase-2, glutathione peroxidase, catalase, matrix metalloproteinase-1). In-vitro UVA radiation induced modulation of genes involved in extracellular matrix homeostasis, oxidative stress, heat shock responses, cell growth, inflammation and epidermal differentiation. Sunscreen pre-application abrogated or significantly reduced these effects, as underlined by unsupervised clustering analysis. The in vivo study confirmed that the sunscreen prevented UVA radiation-induced transcriptional expression of the five studied genes. These findings indicate the high efficacy of a broad-spectrum sunscreen in protecting human skin against UVA-induced gene responses and suggest that this approach is a biologically relevant complement to existing methods.

  9. Iron sensitizes keratinocytes and fibroblasts to UVA-mediated matrix metalloproteinase-1 through TNF-α and ERK activation.

    PubMed

    Jian, Jinlong; Pelle, Edward; Yang, Qing; Pernodet, Nadine; Maes, Daniel; Huang, Xi

    2011-03-01

    Oestrogen deficiency is regarded as the main causative factor in postmenopausal skin ageing and photoageing. While women after menopause experience low levels of oestrogen because of cease of ovarian function, they are also exposed to high levels of iron as a result of cessation of menstruation. In this study, we investigated whether this increase in iron presents a risk to the postmenopausal skin. Because of the lack of appropriate animal models to closely mimic the low oestrogen and high iron conditions, we tested the hypothesis in a high iron and low oestrogen culture model. Here, we showed that primary human dermal fibroblasts exposed to iron did not affect the baseline levels of matrix metalloproteinase-1 (MMP-1) activity. However, the iron-exposed fibroblasts were sensitized to UVA exposure, which resulted in a synergistic increase in MMP-1. UVA activated the three members of MAPK family: ERKs, p38, and JNKs. Additional activation of ERKs by iron contributed to the synergistic increases. Primary normal human epidermal keratinocytes (NHEK) did not respond to iron or UVA exposure as measured by MMP-1, but produced tumor necrosis factor-alpha (TNF-α) in the media, which then stimulated MMP-1 in fibroblasts. Our results indicate that iron and UVA increase MMP-1 activity in dermal fibroblasts not only directly through ERK activation but also by an indirect paracrine loop through TNF-α released by NHEK. We conclude that in addition to oestrogen deficiency, increased iron as a result of menopause could be a novel risk factor by sensitizing postmenopausal skin to solar irradiation.

  10. Apigenin inhibits UVA-induced cytotoxicity in vitro and prevents signs of skin aging in vivo.

    PubMed

    Choi, Sungjin; Youn, Jeungyeun; Kim, Karam; Joo, Da Hye; Shin, Shanghun; Lee, Jeongju; Lee, Hyun Kyung; An, In-Sook; Kwon, Seungbin; Youn, Hae Jeong; Ahn, Kyu Joong; An, Sungkwan; Cha, Hwa Jun

    2016-08-01

    Apigenin (4',5,7-trihydroxyflavone) is a flavone that has been reported to have anti-inflammatory, antioxidant and anti-carcinogenic properties. In this study, we investigated the protective effects of apigenin on skin and found that, in experiments using cells, apigenin restored the viability of normal human dermal fibroblasts (nHDFs), which had been decreased by exposure to ultraviolet (UV) radiation in the UVA range. Using a senescence-associated (SA)-β-gal assay, we also demonstrate that apigenin protects against the UVA-induced senescence of nHDFs. Furthermore, we found that apigenin decreased the expression of the collagenase, matrix metalloproteinase (MMP)-1, in UVA-irradiated nHDFs. UVA, which has been previously identified as a photoaging-inducing factor, has been shown to induce MMP-1 expression. The elevated expression of MMP-1 impairs the collagen matrix, leading to the loss of elasticity and skin dryness. Therefore, we examined the clinical efficacy of apigenin on aged skin, using an apigenin‑containing cream for clinical application. Specifically, we measured dermal density, skin elasticity and the length of fine wrinkles in subjects treated with apigenin cream or the control cream without apigenin. Additionally, we investigated the effects of the apigenin-containing cream on skin texture, moisture and transepidermal water loss (TEWL). From these experiments, we found that the apigenin‑containing cream increased dermal density and elasticity, and reduced fine wrinkle length. It also improved skin evenness, moisture content and TEWL. These results clearly demonstrate the biological effects of apigenin, demonstrating both its cellular and clinical efficacy, and suggest that this compound holds promise as an anti-aging cosmetic ingredient.

  11. Intensity-dependent direct solar radiation- and UVA-induced radical damage to human skin and DNA, lipids and proteins.

    PubMed

    Haywood, Rachel; Andrady, Carima; Kassouf, Nick; Sheppard, Nick

    2011-01-01

    Skin can be exposed to high-intensity UV-radiation in hot countries and during sunbed use; however, the free-radical damage at these intensities is unknown. We used electron spin resonance spectroscopy to measure free-radical generation in ex vivo human skin/substitutes +/- the spin-trap 5,5 dimethyl-1-pyrroline N-oxide (DMPO) exposed to solar-irradiation equivalent to Mediterranean sunlight. Skin-substitutes, model DNA-photosensitizer systems, lipids and proteins were also irradiated with low-intensity UVA/visible light. Without DMPO a broad singlet was detected (using both irradiations) in skin/substitutes, nail-keratin, tendon-collagen, phospholipid and DNA+melanin or riboflavin. In addition to lipid-derived (tentatively tert-alkoxyl/acyl-) and protein radicals detected with DMPO at lower intensities, isotropic carbon-, additional oxygen- and hydrogen-adducts were detected in solar-irradiated skin/substitutes at higher intensities. Carbon-adducts were detected in UVA-irradiated human skin cells, DNA+melanin or riboflavin and soybean-phospholipid. Anisotropic protein-adducts, comparable to adducts in solar-irradiated tendon-collagen, were absent in UVA-irradiated skin fibroblasts suggesting the trapping of extracellular collagen radicals. Absence of hydrogen-adducts in fibroblasts implies formation in the extracellular compartment. We conclude damage at high intensities is part cellular (carbon- and oxygen-radicals) and part extracellular (protein- and hydrogen/H(+)+e(-) ), and skin substitutes are suitable for sunscreen testing. While UVA absorption and lipid-oxidation is direct, DNA and protein-oxidation require photosensitisation.

  12. Iron sensitizes keratinocytes and fibroblasts to UVA-mediated matrix metalloproteinase-1 through TNF-α and ERK activation

    PubMed Central

    Jian, Jinlong; Pelle, Edward; Yang, Qing; Pernodet, Nadine; Maes, Daniel; Huang, Xi

    2010-01-01

    Oestrogen deficiency is regarded as the main causative factor in postmenopausal skin ageing and photoageing. While women after menopause experience low levels of oestrogen because of cease of ovarian function, they are also exposed to high levels of iron as a result of cessation of menstruation. In this study, we investigated whether this increase in iron presents a risk to the postmenopausal skin. Because of the lack of appropriate animal models to closely mimic the low oestrogen and high iron conditions, we tested the hypothesis in a high iron and low oestrogen culture model. Here, we showed that primary human dermal fibroblasts exposed to iron did not affect the baseline levels of matrix metalloproteinase-1 (MMP-1) activity. However, the iron-exposed fibroblasts were sensitized to UVA exposure, which resulted in a synergistic increase in MMP-1. UVA activated the three members of MAPK family: ERKs, p38, and JNKs. Additional activation of ERKs by iron contributed to the synergistic increases. Primary normal human epidermal keratinocytes (NHEK) did not respond to iron or UVA exposure as measured by MMP-1, but produced tumor necrosis factor-alpha (TNF-α) in the media, which then stimulated MMP-1 in fibroblasts. Our results indicate that iron and UVA increase MMP-1 activity in dermal fibroblasts not only directly through ERK activation but also by an indirect paracrine loop through TNF-α released by NHEK. We conclude that in addition to oestrogen deficiency, increased iron as a result of menopause could be a novel risk factor by sensitizing postmenopausal skin to solar irradiation. PMID:20701626

  13. A Class I UV-Blocking (senofilcon A) Soft Contact Lens Prevents UVA-induced Yellow Fluorescence and NADH loss in the Rabbit Lens Nucleus in vivo

    PubMed Central

    Giblin, Frank J.; Lin, Li-Ren; Simpanya, Mukoma F.; Leverenz, Victor R.; Fick, Catherine E.

    2012-01-01

    It is known that fluorescence, much of it caused by UVA light excitation, increases in the aging human lens, resulting in loss of sharp vision. This study used an in vivo animal model to investigate UVA-excited fluorescence in the rabbit lens, which contains a high level of the UVA chromophore NADH, existing both free and bound to λ-crystallin. Also, the ability of a Class I (senofilcon A) soft contact lens to protect against UVA-induced effects on the rabbit lens was tested. Rabbit eyes were irradiated with UVA light in vivo (100 mW/cm2 on the cornea) for 1 hour using monochromatic 365 nm light. Irradiation was conducted in the presence of either a senofilcon A contact lens, a minimally UV-absorbing lotrafilcon A contact lens, or no contact lens at all. Eyes irradiated without a contact lens showed blue 365 nm-excited fluorescence initially, but this changed to intense yellow fluorescence after 1 hour. Isolated, previously irradiated lenses exhibited yellow fluorescence originating from the lens nucleus when viewed under 365 nm light, but showed normal blue fluorescence arising from the cortex. Previously irradiated lenses also exhibited a faint yellow color when observed under visible light. The senofilcon A contact lens protected completely against the UVA-induced effects on fluorescence and lens yellowing, whereas the lotrafilcon A lens showed no protection. The UVA-exposure also produced a 53% loss of total NADH (free plus bound) in the lens nucleus, with only a 13% drop in the anterior cortex. NADH loss in the nucleus was completely prevented with use of a senofilcon A contact lens, but no significant protection was observed with a lotrafilcon A lens. Overall, the senofilcon A lens provided an average of 67% protection against UVA-induced loss of four pyridine nucleotides in four different regions of the lens. HPLC analysis with fluorescence detection indicated a nearly six-fold increase in 365 nm-excited yellow fluorescence arising from lens nuclear

  14. Matrix metalloproteinase-1 inhibitory activities of Morinda citrifolia seed extract and its constituents in UVA-irradiated human dermal fibroblasts.

    PubMed

    Masuda, Megumi; Murata, Kazuya; Naruto, Shunsuke; Uwaya, Akemi; Isami, Fumiyuki; Matsuda, Hideaki

    2012-01-01

    The objective of this study was to examine whether a 50% ethanolic extract (MCS-ext) of the seeds of Morinda citrifolia (noni) and its constituents have matrix metalloproteinase-1 (MMP-1) inhibitory activity in UVA-irradiated normal human dermal fibroblasts (NHDFs). The MCS-ext (10 μg/mL) inhibited MMP-1 secretion from UVA-irradiated NHDFs, without cytotoxic effects, at 48 h after UV exposure. The ethyl acetate-soluble fraction of MCS-ext was the most potent inhibitor of MMP-1 secretion. Among the constituents of the fraction, a lignan, 3,3'-bisdemethylpinoresinol (1), inhibited the MMP-1 secretion at a concentration of 0.3 μM without cytotoxic effects. Furthermore, 1 (0.3 μM) reduced the level of intracellular MMP-1 expression. Other constituents, namely americanin A (2), quercetin (3) and ursolic acid (4), were inactive. To elucidate inhibition mechanisms of MMP-1 expression and secretion, the effect of 1 on mitogen-activated protein kinases (MAPKs) phosphorylation was examined. Western blot analysis revealed that 1 (0.3 μM) reduced the phosphorylations of p38 and c-Jun-N-terminal kinase (JNK). These results suggested that 1 suppresses intracellular MMP-1 expression, and consequent secretion from UVA-irradiated NHDFs, by down-regulation of MAPKs phosphorylation.

  15. Treatment of crystallized-fruit wastewater by UV-A LED photo-Fenton and coagulation-flocculation.

    PubMed

    Rodríguez-Chueca, Jorge; Amor, Carlos; Fernandes, José R; Tavares, Pedro B; Lucas, Marco S; Peres, José A

    2016-02-01

    This work reports the treatment of crystallized-fruit effluents, characterized by a very low biodegradability (BOD5/COD <0.19), through the application of a UV-A LED photo-Fenton process. Firstly, a Box-Behnken design of Response Surface Methodology was applied to achieve the optimal conditions for the UV-A LED photo-Fenton process, trying to maximize the efficiency by saving chemicals and time. Under the optimal conditions ([H2O2] = 5459 mg/L; [Fe(3+)] = 286 mg/L; time >180 min), a COD removal of 45, 64 and 74% was achieved after 360 min, using an irradiance of 23, 70 and 85 W/m(2) respectively. Then a combination of UV-A LED photo-Fenton with coagulation-flocculation-decantation attained a higher COD removal (80%), as well as almost total removal of turbidity (99%) and total suspended solids (95%). Subsequent biodegradability of treated effluents increased, allowing the application of a biological treatment step after the photochemical/CFD with 85 W/m(2).

  16. Photodegradation of pharmaceuticals in the aquatic environment by sunlight and UV-A, -B and -C irradiation.

    PubMed

    Kawabata, Kohei; Sugihara, Kazumi; Sanoh, Seigo; Kitamura, Shigeyuki; Ohta, Shigeru

    2013-01-01

    In order to investigate the effect of sunlight on the persistence and ecotoxicity of pharmaceuticals contaminating the aquatic environment, we exposed nine pharmaceuticals (acetaminophen (AA), amiodarone (AM), dapsone (DP), dexamethasone (DX), indomethacin (IM), naproxen (NP), phenytoin (PH), raloxifene (RL), and sulindac (SL)) in aqueous media to sunlight and to ultraviolet (UV) irradiation at 254, 302 or 365 nm (UV-C, UV-B or UV-A, respectively). Degradation of the pharmaceuticals was monitored by means of high-performance liquid chromatography (HPLC). Sunlight completely degraded AM, DP and DX within 6 hr, and partly degraded the other pharmaceuticals, except AA and PH, which were not degraded. Similar results were obtained with UV-B, while UV-A was less effective (both UV-A and -B are components of sunlight). All the pharmaceuticals were photodegraded by UV-C, which is used for sterilization in sewage treatment plants. Thus, the photodegradation rates of pharmaceuticals are dependent on both chemical structure and the wavelength of UV exposure. Toxicity assay using the luminescent bacteria test (ISO11348) indicated that UV irradiation reduced the toxicity of some pharmaceuticals to aquatic organisms by decreasing their amount (photodegradation) and increased the toxicity of others by generating toxic photoproduct(s). These results indicate the importance of investigating not only parent compounds, but also photoproducts in the risk assessment of pharmaceuticals in aquatic environments.

  17. Phototoxic properties of perfumes containing bergamot oil on human skin: photoprotective effect of UVA and UVB sunscreens.

    PubMed

    Dubertret, L; Serraf-Tircazes, D; Jeanmougin, M; Morlière, P; Averbeck, D; Young, A R

    1990-11-01

    As part of an international cooperative study of the photophysical, photomutagenic and photocarcinogenic properties of bergamot oil and the effect of UVA and UVB sunscreens, the phototoxic properties of model perfumes containing 5, 15 and 50 ppm 5-methoxypsoralen (5-MOP) in bergamot oil with and without a sunscreen have been investigated on human skin. It has been confirmed that the photosensitivity of human skin is maximal 2 h after perfume application. Interestingly the addition of a UVA sunscreen is more efficient for decreasing the phototoxic properties of bergamot oil than is a UVB sunscreen. The addition of sunscreens in a model perfume containing 50 ppm 5-MOP in bergamot oil can reduce the phototoxic properties of this perfume to a toxicity equivalent to that produced by the application of a model perfume containing 15 ppm 5-MOP without sunscreens. However, despite their promising protective effect in vitro, UVB and UVA sunscreens at low concentration (0.5%-1%) in perfumes cannot suppress the phototoxicity of bergamot oil on human skin.

  18. Pea aphid Acyrthosiphon pisum sequesters plant-derived secondary metabolite L-DOPA for wound healing and UVA resistance.

    PubMed

    Zhang, Yi; Wang, Xing-Xing; Zhang, Zhan-Feng; Chen, Nan; Zhu, Jing-Yun; Tian, Hong-Gang; Fan, Yong-Liang; Liu, Tong-Xian

    2016-03-23

    Herbivores can ingest and store plant-synthesized toxic compounds in their bodies, and sequester those compounds for their own benefits. The broad bean, Vicia faba L., contains a high quantity of L-DOPA (L-3,4-dihydroxyphenylalanine), which is toxic to many insects. However, the pea aphid, Acyrthosiphon pisum, can feed on V. faba normally, whereas many other aphid species could not. In this study, we investigated how A. pisum utilizes plant-derived L-DOPA for their own benefit. L-DOPA concentrations in V. faba and A. pisum were analyzed to prove L-DOPA sequestration. L-DOPA toxicity was bioassayed using an artificial diet containing high concentrations of L-DOPA. We found that A. pisum could effectively adapt and store L-DOPA, transmit it from one generation to the next. We also found that L-DOPA sequestration verity differed in different morphs of A. pisum. After analyzing the melanization efficiency in wounds, mortality and deformity of the aphids at different concentrations of L-DOPA under ultraviolet radiation (UVA 365.0 nm for 30 min), we found that A. pisum could enhance L-DOPA assimilation for wound healing and UVA-radiation protection. Therefore, we conclude that A. pisum could acquire L-DOPA and use it to prevent UVA damage. This study reveals a successful co-evolution between A. pisum and V. faba.

  19. UV-A Irradiation Activates Nrf2-Regulated Antioxidant Defense and Induces p53/Caspase3-Dependent Apoptosis in Corneal Endothelial Cells

    PubMed Central

    Liu, Cailing; Vojnovic, Dijana; Kochevar, Irene E.; Jurkunas, Ula V.

    2016-01-01

    Purpose To examine whether Nrf2-regulated antioxidant defense and p53 are activated in human corneal endothelial cells (CEnCs) by environmental levels of ultraviolet A (UV-A), a known stimulator of oxidative stress. Methods Immortalized human CEnCs (HCEnCi) were exposed to UV-A fluences of 2.5, 5, 10, or 25 J/cm2, then allowed to recover for 3 to 24 hours. Control HCEnCi did not receive UV-A. Reactive oxygen species (ROS) were measured using H2DCFDA. Cell cytotoxicity was evaluated by lactate dehydrogenase (LDH) release. Levels of Nrf2, HO-1, NQO-1, p53, and caspase3 were detected by immunnoblotting or real-time PCR. Activated caspase3 was measured by immunoblotting and a fluorescence assay. Results Exposure of HCEnCi to 5, 10, and 25 J/cm2 UV-A increased ROS levels compared with controls. Nrf2, HO-1, and NQO-1 mRNA increased 1.7- to 3.2-fold at 3 and 6 hours after irradiation with 2.5 and 5 J/cm2 UV-A. At 6 hours post irradiation, UV-A (5 J/cm2) enhanced nuclear Nrf2 translocation. At 24 hours post treatment, UV-A (5, 10, and 25 J/cm2) produced a 1.8- to 2.8-fold increase in phospho-p53 and a 2.6- to 6.0-fold increase in activated caspase3 compared with controls, resulting in 20% to 42% cell death. Conclusions Lower fluences of UV-A induce Nrf2-regulated antioxidant defense and higher fluences activate p53 and caspase3, indicating that even near-environmental levels of UV-A may affect normal CEnCs. This data suggest that UV-A may especially damage cells deficient in antioxidant defense, and thus may be involved in the etiology of Fuchs' endothelial corneal dystrophy (FECD). PMID:27127932

  20. NASA-UVA Light Aerospace Alloy and Structures Technology Program: LA(2)ST

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.; Haviland, John K.; Herakovich, Carl T.; Pilkey, Walter D.; Pindera, Marek-Jerzy; Scully, John R.; Stoner, Glenn E.; Thornton, Earl A.; Wawner, Franklin E., Jr.; Wert, John A.

    1993-01-01

    The NASA-UVA Light Aerospace Alloy and Structures Technology (LA(2)ST) Program continues a high level of activity, with projects being conducted by graduate students and faculty advisors in the Departments of Materials Science and Engineering, Civil Engineering and Applied Mechanics, and Mechanical and Aerospace Engineering at the University of Virginia. This work is funded by the NASA-Langley Research Center under Grant NAG-1-745. We report on progress achieved between July 1 and December 31, 1992. The objective of the LA(2)ST Program is to conduct interdisciplinary graduate student research on the performance of next generation, light weight aerospace alloys, composites and thermal gradient structures in collaboration with NASA-Langley researchers. Specific technical objectives are presented for each research project. We generally aim to produce relevant data and basic understanding of material mechanical response, corrosion behavior, and microstructure; new monolithic and composite alloys; advanced processing methods; new solid and fluid mechanics analyses; measurement advances; and critically, a pool of educated graduate students for aerospace technologies.

  1. NASA-UVA light aerospace alloy and structures technology program (LA2ST)

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.; Scully, John R.; Starke, Edgar A., Jr.; Stoner, Glenn E.; Thornton, Earl A.; Wawner, Franklin E., Jr.; Wert, John A.

    1994-01-01

    The NASA-UVA Light Aerospace Alloy and Structures Technology (LA2ST) Program was initiated in 1986, and continues a high level of activity, with projects being conducted by graduate students and faculty advisors in the Departments of Materials Science and Engineering, and Mechanical and Aerospace Engineering at the University of Virginia. This work is funded by the NASA-Langley Research Center under Grant NAG-1-745. Here, we report on progress achieved between July 1 and December 31, 1993. The objective of the LA2ST Program is to conduct interdisciplinary graduate student research on the performance of next generation, light weight aerospace alloys, composites and thermal gradient structures in collaboration with NASA-Langley researchers. Specific technical objectives are presented for each research project. We generally aim to produce relevant data and basic understanding of material mechanical response, environmental/corrosion behavior, and microstructure; new monolithic and composite alloys; advanced processing methods; new solid and fluid mechanics analyses; measurement and modeling advances; and critically, a pool of educated graduate students for aerospace technologies.

  2. NASA-UVA light aerospace alloy and structures technology program (LA2ST)

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.

    1992-01-01

    The NASA-UVa Light Aerospace Alloy and Structure Technology (LAST) Program continues to maintain a high level of activity, with projects being conducted by graduate students and faculty advisors in the Departments of Materials Science and Engineering, Civil Engineering and Applied Mechanics, and Mechanical and Aerospace Engineering at the University of Virginia. This work is funded by the NASA-Langley Research Center under Grant NAG-1-745. Here, we report on progress achieved between January 1 and June 30, 1992. The objectives of the LA2ST Program is to conduct interdisciplinary graduate student research on the performance of the next generation, light weight aerospace alloys, composites and thermal gradient structures in collaboration with Langley researchers. Technical objectives are established for each research project. We aim to produce relevant data and basic understanding of material mechanical response, corrosion behavior, and microstructure; new monolithic and composite alloys; advanced processing methods; new solid and fluid mechanics analyses; measurement advances; and critically, a pool of educated graduate students for aerospace technologies. The accomplishments presented in this report cover topics including: (1) Mechanical and Environmental Degradation Mechanisms in Advance Light Metals and Composites; (2) Aerospace Materials Science; (3) Mechanics of Materials and Composites for Aerospace Structures; and (4) Thermal Gradient Structures.

  3. Pharmacokinetic and toxicology assessment of INTERCEPT (S-59 and UVA treated) platelets.

    PubMed

    Ciaravi, V; McCullough, T; Dayan, A D

    2001-10-01

    The pathogen inactivation process developed by Cerus and Baxter Healthcare Corporations uses the psoralen, S-59 (amotosalen) in an ex vivo photochemical treatment (PCT) process to inactivate viruses, bacteria, protozoans, and leukocytes in platelet concentrates and plasma. Studies were performed by intravenous infusion of S-59 PCT formulations +/- compound adsorption device (CAD) treatment and with non-UVA illuminated S-59, using doses that were multiples of potential clinical exposures. The studies comprised full pharmacokinetic, single- and repeated-dose (up to 13 weeks duration) toxicity, safety pharmacology (CNS, renal, and cardiovascular), reproductive toxicity, genotoxicity, carcinogenicity testing in the p53(+/-) mouse, vein irritation, and phototoxicity. No specific target organ toxicity (clinical or histopathological), reproductive toxicity, or carcinogenicity was observed. S-59 and/or PCT formulations demonstrated CNS, ECG, and phototoxicity only at supraclinical doses. Based on the extremely large safety margins (>30,000-fold expected clinical exposures), the CNS and ECG observations are not considered to have any toxicological relevance. Additionally, after a complete assessment, mutagenicity and phototoxicity results are not considered relevant for the proposed use of INTERCEPT platelets. Thus, the results of an extensive series of in vitro and in vivo studies have not demonstrated any toxicologically relevant effects of platelet concentrates prepared by the INTERCEPT system.

  4. A simplified procedure for semi-targeted lipidomic analysis of oxidized phosphatidylcholines induced by UVA irradiation.

    PubMed

    Gruber, Florian; Bicker, Wolfgang; Oskolkova, Olga V; Tschachler, Erwin; Bochkov, Valery N

    2012-06-01

    Oxidized phospholipids (OxPLs) are increasingly recognized as signaling mediators that are not only markers of oxidative stress but are also "makers" of pathology relevant to disease pathogenesis. Understanding the biological role of individual molecular species of OxPLs requires the knowledge of their concentration kinetics in cells and tissues. In this work, we describe a straightforward "fingerprinting" procedure for analysis of a broad spectrum of molecular species generated by oxidation of the four most abundant species of polyunsaturated phosphatidylcholines (OxPCs). The approach is based on liquid-liquid extraction followed by reversed-phase HPLC coupled to electrospray ionization MS/MS. More than 500 peaks corresponding in retention properties to polar and oxidized PCs were detected within 8 min at 99 m/z precursor values using a single diagnostic product ion in extracts from human dermal fibroblasts. Two hundred seventeen of these peaks were fluence-dependently and statistically significantly increased upon exposure of cells to UVA irradiation, suggesting that these are genuine oxidized or oxidatively fragmented species. This method of semitargeted lipidomic analysis may serve as a simple first step for characterization of specific "signatures" of OxPCs produced by different types of oxidative stress in order to select the most informative peaks for identification of their molecular structure and biological role.

  5. Low-flow transport models for conservative and sorbed solutes; Uvas Creek, near Morgan Hill, California

    USGS Publications Warehouse

    Jackman, A.P.; Walters, R.A.; Kennedy, V.C.

    1984-01-01

    Models describing low-flow transport of conservative (nonreactive) and reactive solutes, which adsorb on the streambed, are developed and tested. Temporary storage within the bed plays an important role in solute movement. Three different models of bed-storage processes are developed for conservative solutes. One model assumes the bed is a well-mixed, nondiffusing, nonreacting zone. Solute flux into the bed is then proportional to the difference between stream and bed-solute concentrations. A second model assumes that solute is transported within the bed by a vertical diffusion process. The bed-solute concentration, which matches the stream concentration at the interface, varies with depth in the bed according to Fick 's law. A third model assumes convection in the downstream direction occurs in certain parts of the bed, while the mechanism of the first model functions elsewhere. Storage of absorbing species is assumed to occur by equilibrium adsorption within streambed particles. Uptake rate is described by an intraparticle diffusion process. Model equations were solved using finite element numerical methods. Models were calibrated using data from a 24-hour injection of conservative chloride and adsorptive Sr ions at Uvas Creek near Morgan Hill, California. All models predict well except for some overestimation by the adsorption model during dieaway. (USGS)

  6. UVA-induced reset of hydroxyl radical ultradian rhythm improves temporal lipid production in Chlorella vulgaris.

    PubMed

    Balan, Ranjini; Suraishkumar, G K

    2014-01-01

    We report for the first time that the endogenous, pseudo-steady-state, specific intracellular levels of the hydroxyl radical (si-OH) oscillate in an ultradian fashion (model system: the microalga, Chlorella vulgaris), and also characterize the various rhythm parameters. The ultradian rhythm in the endogenous levels of the si-OH occurred with an approximately 6 h period in the daily cycle of light and darkness. Further, we expected that the rhythm reset to a shorter period could rapidly switch the cellular redox states that could favor lipid accumulation. We reset the endogenous rhythm through entrainment with UVA radiation, and generated two new ultradian rhythms with periods of approximately 2.97 h and 3.8 h in the light phase and dark phase, respectively. The reset increased the window of maximum lipid accumulation from 6 h to 12 h concomitant with the onset of the ultradian rhythms. Further, the saturated fatty acid content increased approximately to 80% of total lipid content, corresponding to the peak maxima of the hydroxyl radical levels in the reset rhythm.

  7. NASA-UVA light aerospace alloy and structures technology program (LA2ST)

    NASA Technical Reports Server (NTRS)

    Starke, Edgar A., Jr.; Gangloff, Richard P.; Herakovich, Carl T.; Scully, John R.; Shiflet, Gary J.; Stoner, Glenn E.; Wert, John A.

    1995-01-01

    The NASA-UVa Light Aerospace Alloy and Structures Technology (LA2ST) Program was initiated in 1986 and continues with a high level of activity. Projects are being conducted by graduate students and faculty advisors in the Department of Materials Science and Engineering, as well as in the Department of Civil Engineering and Applied Mechanics, at the University of Virginia. Here, we report on progress achieved between July 1 and December 31, 1994. The objective of the LA2ST Program is to conduct interdisciplinary graduate student research on the performance of next generation, light-weight aerospace alloys, composites and thermal gradient structures in collaboration with NASA-Langley researchers. Specific technical objectives are presented for each research project. We generally aim to produce relevant data and basic understanding of material mechanical response, environmental/corrosion behavior, and microstructure; new monolithic and composite alloys; advanced processing methods; new solid and fluid mechanics analyses; measurement and modeling advances; and a pool of educated graduate students for aerospace technologies.

  8. Solid surface photochemistry of montmorillonite: mechanisms for the arsenite oxidation under UV-A irradiation.

    PubMed

    Yuan, Yanan; Wang, Yajie; Ding, Wei; Li, Jinjun; Wu, Feng

    2016-01-01

    Transformation of inorganic arsenic species has drawn great concern in recent decades because of worldwide and speciation-dependent pollution and the hazards that they pose to the environment and to human health. As(III) photooxidation in aquatic systems has received much attention, but little is known about photochemical transformation of arsenic species on top soil. As(III) photooxidation on natural montmorillonite under UV-A radiation was investigated by using a moisture- and temperature-controlled photochemical chamber with two black-light lamps. Initial As(III) concentration, pH, layer thickness, humic acid (HA) concentration, the presence of additional iron ions, and the contribution of reactive oxygen species (ROS) were examined. The results show that pH values of the clay layers greatly influenced As(III) photooxidation on montmorillonite. As(III) photooxidation followed the Langmuir-Hinshelwood model. HA and additional iron ions greatly promoted photooxidation, but excess Fe(II) competed with As(III) for oxidation by ROS. Scavenging experiments revealed that natural montmorillonite induced the conversion of As(III) to As(V) by generating ROS (mainly HO(•) and HO2(•)/O2(•-)) and that HO(•) radical was the predominant oxidant in this system. Our work demonstrates that photooxidation on the surface of natural clay minerals in top soil can be important to As(III) transformation. This allows understanding and predicting the speciation and behavior of arsenic on the soil surface.

  9. Phenylmercury degradation by heterogeneous photocatalysis assisted by UV-A light.

    PubMed

    Miranda, Cristian; Yáñez, Jorge; Contreras, David; Zaror, Claudio; Mansilla, Héctor D

    2013-01-01

    Photocatalytic degradation of phenylmercury was studied using TiO2 in aqueous suspension assisted by UV-A irradiation. Reaction conditions, such as pH and amount of TiO2 were set using a factorial design of experiments resulting in a greater influence of pH on phenylmercury degradation. Hg (II) reduction and simultaneous oxidation of aromatic group was observed. Optimum reaction conditions were obtained under nitrogen atmosphere at pH 10 and 0.35 g/L(-1) TiO2. Under these conditions almost 100% reduction of mercury was reached after 30 min UV irradiation. Total mercury reduction was achieved after 40 min reaction under saturated oxygen. Furthermore, phenol and diphenylmercury were identified as intermediate products of oxidation. It was observed that a major fraction of the reduced mercury was removed as metallic vapor by gas stripping, whereas a minor fraction was adsorbed on the catalyst surface, probably as Hg(OH)2. Under optimal conditions obtained by multivariable analysis, total mineralization of organic matter was achieved after about 60-min irradiation.

  10. Decreased frost hardiness of Vaccinium vitis-idaea in reponse to UV-A radiation.

    PubMed

    Taulavuori, Kari; Keränen, Johanna; Suokanerva, Hanne; Lakkala, Kaisa; Huttunen, Satu; Laine, Kari; Taulavuori, Erja

    2012-08-01

    The aim of this study was to investigate plant frost hardiness responses to ultraviolet (UV) radiation, since the few results reported are largely contradictory. It was hypothesized that functional adaptation of life forms could explain these contradictions. Dwarf shrubs and tree seedlings, representing both evergreen and deciduous forms, were tested (Vaccinium vitis-idaea, Vaccinium myrtillus, Pinus sylvestris, Betula pubescens and its red form f. rubra). The research was performed in Sodankylä, Northern Finland (67°N), with enhanced UV-B- and UV-A-radiation treatments between 2002 and 2009. Plant frost hardiness was determined using the freeze-induced electrolyte leakage method in early autumn, during the onset of the frost hardening process. Additional physiological variables (malondialdehyde, glutathione, total phenols, C and N contents) were analyzed in V. vitis-idaea to explain the possible responses. These variables did not respond significantly to UV-radiation treatments, but explained the frost hardiness well (r² = 0.678). The main finding was that frost hardiness decreased in the evergreen shrub V. vitis-idaea, particularly with enhanced UV-A radiation. No significant responses were observed with the other plants. Therefore, this study does not support the idea that enhanced UV radiation could increase plant frost hardiness.

  11. NASA-UVA Light Aerospace Alloy and Structures Technology Program (LA2ST)

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.; Scully, John R.; Stoner, Glenn E.; Thornton, Earl A.; Wawner, Franklin E., Jr.; Wert, John A.

    1993-01-01

    The NASA-UVA Light Aerospace Alloy and Structures Technology (LA2ST) Program continues a high level of activity. Progress achieved between 1 Jan. and 30 Jun. 1993 is reported. The objective of the LA2ST Program is to conduct interdisciplinary graduate student research on the performance of next generation, light weight aerospace alloys, composites, and thermal gradient structures in collaboration with NASA-Langley researchers. The following projects are addressed: environmental fatigue of Al-Li-Cu alloys; mechanisms of localized corrosion and environmental fracture in Al-Cu-Li-Mg-Ag alloy X2095 and compositional variations; the effect of zinc additions on the precipitation and stress corrosion cracking behavior of alloy 8090; hydrogen interactions with Al-Li-Cu alloy 2090 and model alloys; metastable pitting of aluminum alloys; cryogenic fracture toughness of Al-Cu-Li + In alloys; the fracture toughness of Weldalite (TM); elevated temperature cracking of advanced I/M aluminum alloys; response of Ti-1100/SCS-6 composites to thermal exposure; superplastic forming of Weldalite (TM); research to incorporate environmental effects into fracture mechanics fatigue life prediction codes such as NASA FLAGRO; and thermoviscoplastic behavior.

  12. Protective effect of porphyra-334 on UVA-induced photoaging in human skin fibroblasts.

    PubMed

    Ryu, Jina; Park, Su-Jin; Kim, In-Hye; Choi, Youn Hee; Nam, Taek-Jeong

    2014-09-01

    The significant increase in life expectancy is closely related to the growing interest in the impact of aging on the function and appearance of the skin. Skin aging is influenced by several factors, and solar ultraviolet (UV) irradiation is considered one of the most important causes of skin photoaging. The aim of this study was to examine the anti-photoaging role of porphyra-334 from Porphyra (P.) yezoensis, a mycosporine-like amino acid (MAA), using high-performance liquid chromatography (HPLC), and electrospray ionization‑mass spectrometry (ESI-MS). In the present study, extracted UV‑absorbing compounds from P. yezoensis included palythine, asterina-330 and porphyra-334. Porphyra-334 was the most abundant MAA in P. yezoensis, and it was therefore used for conducting antiphotoaging experiments. The effect of porphyra-334 on the prevention of photoaging was investigated by measuring reactive oxygen species (ROS) production and matrix metalloproteinase (MMP) levels, as well as extracellular matrix (ECM) components and protein expression in UVA‑irradiated human skin fibroblasts. Porphyra-334 suppressed ROS production and the expression of MMPs following UVA irradiation, while increasing levels of ECM components, such as procollagen, type I collagen, elastin. These results suggest that porphyra-334 has various applications in cosmetics and toiletries because of its anti‑photoaging activities and may serve as a novel anti-aging agent.

  13. NASA-UVA Light Aerospace Alloy and Structures Technology Program (LA2ST)

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.; Starke, Edgar A., Jr.; Kelly, Robert G.; Scully, John R.; Shiflet, Gary J.; Stoner, Glenn E.; Wert, John A.

    1997-01-01

    The NASA-UVA Light Aerospace Alloy and Structures Technology (LA2ST) Program was initiated in 1986 and continues with a high level of activity. Here, we report on progress achieved between July I and December 31, 1996. The objective of the LA2ST Program is to conduct interdisciplinary graduate student research on the performance of next generation, light-weight aerospace alloys, composites and thermal gradient structures in collaboration with NASA-Langley researchers. Specific technical objectives are presented for each research project. We generally aim to produce relevant data and basic understanding of material mechanical response, environmental/corrosion behavior, and microstructure; new monolithic and composite alloys; advanced processing methods; new solid and fluid mechanics analyses; measurement and modeling advances; and a pool of educated graduate students for aerospace technologies. The accomplishments presented in this report are summarized as follows. Three research areas are being actively investigated, including: (1) Mechanical and Environmental Degradation Mechanisms in Advanced Light Metals, (2) Aerospace Materials Science, and (3) Mechanics of Materials for Light Aerospace Structures.

  14. NASA-UVA Light Aerospace Alloy and Structures Technology Program (LA2ST)

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.

    1994-01-01

    The NASA-UVA Light Aerospace Alloy and Structures Technology (LA2ST) Program was initiated in 1986 and continues with a high level of activity. Projects are being conducted by graduate students and faculty advisors in the Department of Materials Science and Engineering, as well as in the Department of Civil Engineering and Applied Mechanics, at the University of Virginia. This work is funded by the NASA-Langley Research Center under Grant NAG-1-745. Here, we report on progress achieved between January 1 and June 30, 1994. These results were presented at the Fifth Annual NASA LA2ST Grant Review Meeting held at the Langley Research Center in July of 1994. The objective of the LA2ST Program is to conduct interdisciplinary graduate student research on the performance of next generation, lightweight aerospace alloys, composites, and thermal gradient structures in collaboration with NASA-Langley researchers. Specific technical objectives are presented for each research project. We generally aim to produce relevant data and basic understanding of material mechanical response, environmental/corrosion behavior, and microstructure; new monolithic and composite alloys; advanced processing methods; new solid and fluid mechanics analyses; measurement and modeling advances; and a pool of educated graduate students for aerospace technologies.

  15. Enzymatic Resistance of Corneas Crosslinked Using Riboflavin in Conjunction With Low Energy, High Energy, and Pulsed UVA Irradiation Modes

    PubMed Central

    Aldahlawi, Nada H.; Hayes, Sally; O'Brart, David P. S.; Akhbanbetova, Alina; Littlechild, Stacy L.; Meek, Keith M.

    2016-01-01

    Purpose To investigate the effect of various riboflavin/ultraviolet light (UVA) crosslinking (CXL) protocols on corneal enzymatic resistance. Methods A total of 66 enucleated porcine eyes, with the corneal epithelium removed, were divided into 6 groups. Group 1 remained untreated. Groups 2 to 6 received riboflavin/dextran for 30 minutes. Group 3 underwent standard CXL (SCXL) with 3 mW/cm2 UVA for 30 minutes (total energy dose 5.4 J/cm2). Groups 4 and 5 underwent high intensity CXL (HCXL) using 30 mW/cm2 UVA for 3 minutes (5.4 J/cm2) and 30 mW/cm2 for 4 minutes (7.2 J/cm2), respectively. Group 6 was exposed to 8 minutes of 30 mW/cm2 UVA in a 10-second on/10-second off pulsed-radiation mode (p-HCXL; 7.2 J/cm2). A central 8-mm disk from each cornea was submerged in pepsin digest solution at 23°C and measured daily. After 13 days, the dry weight was recorded from 5 samples in each group. Results The CXL-treated corneas took longer to digest than nonirradiated corneas (P < 0.0001). Differences in digestion time also were observed between CXL groups, such that, HCXL (5.4 J/cm2) < SCXL (5.4 J/cm2) < HCXL (7.2 J/cm2) < p-HCXL (7.2 J/cm2; P < 0.0001). The dry weight of the SCXL (5.4 J/cm2) group was higher than the HCXL (5.4 and 7.2 J/cm2; P < 0.001) and p-HCXL 7.2 J/cm2 (P <0.05) groups. No difference was detected between the HCXL and p-HCXL 7.2 J/cm2 groups. Conclusions The intensity and distribution of the crosslinks formed within the cornea vary with different UVA protocols. The precise location and amount of crosslinking needed to prevent disease progression is unknown. PMID:27046119

  16. Activation of Nrf2 Reduces UVA-Mediated MMP-1 Upregulation via MAPK/AP-1 Signaling Cascades: The Photoprotective Effects of Sulforaphane and Hispidulin

    PubMed Central

    Chaiprasongsuk, Anyamanee; Lohakul, Jinaphat; Soontrapa, Kitipong; Sampattavanich, Somponnat; Akarasereenont, Pravit

    2017-01-01

    UVA irradiation plays a role in premature aging of the skin through triggering oxidative stress-associated stimulation of matrix metalloproteinase-1 (MMP-1) responsible for collagen degradation, a hallmark of photoaged skin. Compounds that can activate nuclear factor E2-related factor 2 (Nrf2), a transcription factor regulating antioxidant gene expression, should therefore serve as effective antiphotoaging agents. We investigated whether genetic silencing of Nrf2 could relieve UVA-mediated MMP-1 upregulation via activation of mitogen-activated protein kinase (MAPK)/activator protein 1 (AP-1) signaling using human keratinocyte cell line (HaCaT). Antiphotoaging effects of hispidulin (HPD) and sulforaphane (SFN) were assessed on their abilities to activate Nrf2 in controlling MMP-1 and collagen expressions in association with phosphorylation of MAPKs (extracellular signal-regulated kinase, c-Jun N-terminal kinase, and p38), c-Jun, and c-Fos, using the skin of BALB/c mice subjected to repetitive UVA irradiation. Our findings suggested that depletion of Nrf2 promoted both mRNA expression and activity of MMP-1 in the UVA-irradiated HaCaT cells. Treatment of Nrf2 knocked-down HaCaT cells with MAPK inhibitors significantly suppressed UVA-induced MMP-1 and AP-1 activities. Moreover, pretreatment of the mouse skin with HPD and SFN, which could activate Nrf2, provided protective effects against UVA-mediated MMP-1 induction and collagen depletion in correlation with the decreased levels of phosphorylated MAPKs, c-Jun, and c-Fos in the mouse skin. In conclusion, Nrf2 could influence UVA-mediated MMP-1 upregulation through the MAPK/AP-1 signaling cascades. HPD and SFN may therefore represent promising antiphotoaging candidates. PMID:28011874

  17. Impact of UV-A radiation on the performance of aphids and whiteflies and on the leaf chemistry of their host plants.

    PubMed

    Dáder, Beatriz; Gwynn-Jones, Dylan; Moreno, Aránzazu; Winters, Ana; Fereres, Alberto

    2014-09-05

    Ultraviolet (UV) radiation directly regulates a multitude of herbivore life processes, in addition to indirectly affecting insect success via changes in plant chemistry and morphogenesis. Here we looked at plant and insect (aphid and whitefly) exposure to supplemental UV-A radiation in the glasshouse environment and investigated effects on insect population growth. Glasshouse grown peppers and eggplants were grown from seed inside cages covered by novel plastic filters, one transparent and the other opaque to UV-A radiation. At a 10-true leaf stage for peppers (53 days) and 4-true leaf stage for eggplants (34 days), plants were harvested for chemical analysis and infested by aphids and whiteflies, respectively. Clip-cages were used to introduce and monitor the insect fitness and populations of the pests studied. Insect pre-reproductive period, fecundity, fertility and intrinsic rate of natural increase were assessed. Crop growth was monitored weekly for 7 and 12 weeks throughout the crop cycle of peppers and eggplants, respectively. At the end of the insect fitness experiment, plants were harvested (68 days and 18-true leaf stage for peppers, and 104 days and 12-true leaf stage for eggplants) and leaves analysed for secondary metabolites, soluble carbohydrates, amino acids, total proteins and photosynthetic pigments. Our results demonstrate for the first time, that UV-A modulates plant chemistry with implications for insect pests. Both plant species responded directly to UV-A by producing shorter stems but this effect was only significant in pepper whilst UV-A did not affect the leaf area of either species. Importantly, in pepper, the UV-A treated plants contained higher contents of secondary metabolites, leaf soluble carbohydrates, free amino acids and total content of protein. Such changes in tissue chemistry may have indirectly promoted aphid performance. For eggplants, chlorophylls a and b, and carotenoid levels decreased with supplemental UV-A over the entire

  18. The role and fate of inorganic nitrogen species during UVA/TiO₂ disinfection.

    PubMed

    Zuo, XiaoJun; Hu, Jiangyong; Chen, MinDong

    2015-09-01

    Inorganic nitrogen species have three states including ammonia nitrogen (NH4(+)/NH3), nitrite (NO2(-)) and nitrate (NO3(-)) and are often found in the disinfection system. However, no available literature could be found on their role and fate in photocatalytic disinfection systems. In this study, batch experiments were conducted to investigate bacteria inactivation, H2O2 generated and inorganic nitrogen variation to understand the role and fate of inorganic nitrogen species during UVA/TiO2 disinfection and evaluate effects of initial pH and bacteria levels on the role and fate. NH4(+)/NH3 and NO2(-) inhibited the photocatalytic disinfection process obviously. It could be confirmed through that H2O2 yield used for pathogen inactivation was dependent on NH4(+)/NH3 and NO2(-) levels. The NH4(+)/NH3 remaining, NH4(+) remaining and NO3(-) yields in only NH4(+)/NH3 photocatalytic oxidation experiments were obviously different from the corresponding values in the photocatalytic disinfection experiments with NH4(+)/NH3, which confirmed that photocatalytic disinfection had an obvious effect on the fate of NH4(+)/NH3. However, photocatalytic disinfection had slight effects on the fate of NO2(-) and NO3(-). Escherischia coli inactivation rate was the highest in neutral solutions (Initial pH 7) while the lowest in alkaline solutions (Initial pH 8.5). The decrease of NH4(+)/NH3 in alkaline solutions was the most significant. In turn, the photocatalysis of NO2(-) was more evident in acidic solutions. E. coli inactivation was reduced with the increase of initial E. coli concentrations. The initial bacteria concentrations significantly influenced the increase of NH4(+)/NH3, NH4(+) and NO3(-), but slightly impacted the decrease of NO2(-).

  19. Modulation of c-jun and c-fos transcription by UVB and UVA radiations in human dermal fibroblasts and KB cells.

    PubMed

    Soriani, M; Hejmadi, V; Tyrrell, R M

    2000-05-01

    We have previously demonstrated that the oxidizing component of ultraviolet-A (UVA) plays a central role in the activation of the nuclear oncogene and transcription factor, c-fos, in cultured human skin fibroblasts. We have now shown that expression of both c-jun and c-fos (AP-1) family of transcription factors is modulated by short and long wavelength solar ultraviolet (UV) radiation in human fibroblasts and human KB cells. UVA radiation activated c-jun and c-fos in both fibroblasts and KB cells, whereas ultraviolet-B (UVB) radiation activates such oncogenes only in KB cells. Moreover, decreasing the intracellular levels of reducing equivalents in human fibroblasts by glutathione (GSH) depletion lowered the UVA dose threshold for c-jun and c-fos activation several-fold and greatly amplified the UVA-mediated activation of such genes. A more modest effect was observed in GSH-depleted KB cells. In both GSH-depleted fibroblasts and KB cells, UVB radiation failed to amplify c-jun and c-fos activation indicating that the oxidative component of UVB plays a minor role in the modulation of such oncogene expression. These findings clearly indicate that both c-jun and c-fos are activated by the oxidizing component of UVA radiation in human fibroblasts and KB cells, while UVB-mediated modulation seems to be restricted to human epithelial cells and does not involve oxidizing intermediates.

  20. Effect of UVC, UVB, UVA and a solar simulator on the survival of mouse melanoma cell lines differing in melanin content

    SciTech Connect

    Hill, H.Z.; Hill, G.J.; Cieszka, K.; Azure, M.

    1994-12-31

    These studies were designed to determine the survival of cells that vary in constitutive pigment levels after exposure to different UV wave lengths. The lamps employed emitted UVC (near monochromatic 254 nm), UVB (Philips TL01-88.7% of UV output is UVB), UVA (Philips HPW125-89% of output is at 365 nm) and Westinghouse FS20 (broad band UVB and UVA). Dish lids were used to cut off UVC in the UVB and FS20 experiments and 0.25 inch plate glass was used to cut off UVB in the UVA experiments. UVC photons interact with putative intracellular photosensitizers which in turn convert O{sub 2} to active oxygen species which damage DNA to produce strand breaks, cross links and base damage. UVB acts by both mechanisms. The two cell lines studied were Cloudman S91/I3 (3.6 pg melanin/cell) and the closely related S91/amel (1.2 pg melanin/cell). Attached cells were covered with Ca{sup ++} and Mg{sup ++} free PBS and irradiated in the cold. Colonies were scored after 2 weeks. The two cell lines exhibit similar survival kinetics after UVC. S91/IE is more sensitive to killing by either UVB (TL01) or UVA. However, S91/amel cells are more sensitive to killing by UVB plus UVA (FS20). It is clear that UV of different qualities can interact to produce effects that would not be predicted based on responses to monochromatic wave lengths.

  1. Gene Expression Patterns Associated with the Biosynthesis of the Sunscreen Scytonemin in Nostoc punctiforme ATCC 29133 in Response to UVA Radiation▿

    PubMed Central

    Soule, Tanya; Garcia-Pichel, Ferran; Stout, Valerie

    2009-01-01

    Under exposure to UV radiation, some cyanobacteria synthesize sunscreen compounds. Scytonemin is a heterocyclic indole-alkaloid sunscreen, the synthesis of which is induced upon exposure to UVA (long-wavelength UV) radiation. We previously identified and characterized an 18-gene cluster associated with scytonemin biosynthesis in the cyanobacterium Nostoc punctiforme ATCC 29133; we now report on the expression response of these genes to a step-up shift in UVA exposure. Using quantitative PCR on cDNAs from the N. punctiforme transcriptome and primers targeting each of the 18 genes in the cluster, we followed their differential expression in parallel subcultures incubated with and without UVA. All 18 genes are induced by UVA irradiation, with relative transcription levels that generally peak after 48 h of continuous UVA exposure. A five-gene cluster implicated in the process of scytonemin biosynthesis solely on the basis of comparative genomics was also upregulated. Furthermore, we demonstrate that all of the genes in the18-gene region are cotranscribed as part of a single transcriptional unit. PMID:19429608

  2. Nrf2 and NF-κB Signaling Pathways Contribute to Porphyra-334-Mediated Inhibition of UVA-Induced Inflammation in Skin Fibroblasts.

    PubMed

    Ryu, Jina; Kwon, Mi-Jin; Nam, Taek-Jeong

    2015-07-31

    In this study, we examined the protective effects of porphyra-334 against UVA-irradiated cellular damage and elucidated the underlying mechanisms. Porphyra-334 prevented UVA-induced cell death and exhibited scavenging activities against intracellular oxidative stress induced by UVA irradiation in skin fibroblasts. We found that porphyra-334 significantly reduced the secretion and expression of IL-6 and TNF-α, reduced nuclear expression of Nuclear factor-κB (NF-κB), and sustained NF-E2-related factor 2 (Nrf2) activation. Further mechanism research revealed that porphyra-334 promoted the Nrf2 signaling pathway in UVA-irradiated skin fibroblasts. Our results show that the antioxidant effect of porphyra-334 is due to the direct scavenging of oxidative stress and its inhibitory effects on NF-κB-dependent inflammatory genes, such as IL-6 and TNF-κ. Therefore, we hypothesize that boosting the Nrf2- NF-κB-dependent response to counteract environmental stress is a promising strategy for the prevention of UVA-related damage.

  3. Removal of penicillin G from aqueous phase by Fe+3-TiO2/UV-A process

    PubMed Central

    2014-01-01

    Background Anomalous use of antibiotics and their entrance into the environment have increased concerns around the world. These compounds enter the environment through an incomplete metabolism and a considerable amount of them cannot be removed using conventional wastewater treatment. Therefore, the main objectives of this research are evaluation of the feasibility of using ultraviolet radiation (UV-A) and fortified nanoparticles of titanium dioxide (TiO2) doped with Fe+3 to remove penicillin G (PENG) from aqueous phase and determining the optimum conditions for maximum removal efficiency. Results The results showed that the maximum removal rate of penicillin G occurred in acidic pH (pH = 3) in the presence of 90 mg/L Fe+3-TiO2 catalyst. In addition, an increase in pH caused a decrease in penicillin G removal rate. As the initial concentration of penicillin G increased, the removal rate of antibiotic decreased. Moreover, due to the effect of UV on catalyst activation in Fe+3-TiO2/UV-A process, a significant increase was observed in the rate of antibiotic removal. All of the variables in the process had a statistically significant effect (p < 0.001). Conclusion The findings demonstrated that the antibiotic removal rate increased by decreasing pH and increasing the amount of catalyst and contact time. In conclusion, Fe+3-TiO2/UV-A process is an appropriate method for reducing penicillin G in polluted water resources. PMID:24598354

  4. The effect of white light and UV-A on the green autofluorescence of the rabbit lens in vivo.

    PubMed

    Van Vreeswijk, H; Boets, E P; Van Best, J A

    1993-03-01

    The part of the light spectrum which is responsible for an increase of lenticular green autofluorescence upon white light exposure was determined for the rabbit. The increase of autofluorescence as a function of the light energy was measured, to assess a possible threshold energy for lens alterations. Thirteen rabbits (Chinchilla Greys) were used. An area of 3 or 4.7 mm2 of the lens was exposed to light from a standard tungsten halogen lamp (250 W, lambda = 360-720 nm). Wavelength selection was performed with the use of light filters. The light dose was adjusted by varying the exposure time between 15 min and 180 min. The green lenticular autofluorescence (lambda exc = 420-490 nm, lambda fluor = 530-600 nm) was measured with a fluorophotometer. A significant increase of lenticular autofluorescence after exposure was observed only if the exposure light contained high wavelength UV-A (lambda = 360-400 nm; 0.8% of the total white light energy); additional white light (without UV-A; up to 13 kJ cm-2) did not have any effect on autofluorescence. The autofluorescence returned to pre-exposure values within 4 days. No lesions could be seen on slitlamp examination. The autofluorescence after exposure to UV-A increased linearly with the exposure energy from 13 J cm-2 (14 mW cm-2 for 15 min) up to 155 J cm-2. The increase was 2.0% of the pre-exposure value per J cm-2 and the correlation coefficient 0.94, P < 0.001. A threshold energy was not found.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. The molecular characterization by SSRs reveals a new South Italian kinship and the origin of the cultivar Uva di Troia.

    PubMed

    Bergamini, C; Perniola, R; Cardone, M F; Gasparro, M; Pepe, R; Caputo, A R; Antonacci, D

    2016-01-01

    Vitis vinifera L. varieties were spread through cuttings following historic migrations of people, trades, or after biological crises due to pests outbreaks. Some today's varieties could be more than a 1000 years old and, although over the centuries these varieties generated most of the remaining cultivars, their origin could be impossible to track back. The Italian grapevine biodiversity is one of most important, most likely due to its strategic position in the middle of the Mediterranean sea. Unravelling of its structure is challenging because of its complexity and the lack of historical documentation. In this paper molecular data are compared with historical documentations. Simple Sequence Repeats fingerprinting are molecular markers best suited to investigate genetic relationships and identify pedigrees. South-Italian germplasm was studied with 54 nuclear microsatellites. A family was identified, consisting of two parents and three siblings and further genetically characterized with six nuclear and five chloroplast microsatellites and described with ampelographic and phylometric analysis. Although these latter were not informative for the kinship identification. The common Bombino bianco was the female parent and the previously unknown Uva rosa antica was the male parent. Bombino nero, Impigno and the popular Uva di Troia, all typical of the south-east Italy, were the offspring. Further research showed that the Uva rosa antica was a synonym of Quagliano and Bouteillan noir, both minor varieties. Quagliano was considered to be autochthonous of some alpine valleys in the north-west of Italy and Bouteillan noir is a neglected variety of Vancluse in France. This finding uncovers the intricate nature of Italian grape cultivars, considered peculiar of an area, but possibly being the remains of ancient latin founding varieties. Consequently, intriguing new hypotheses are discussed and some conclusions are drawn, based on the peculiar geographical origin of the parents

  6. Antimicrobial photodisinfection with Zn(II) phthalocyanine adsorbed on TiO2 upon UVA and red irradiation

    NASA Astrophysics Data System (ADS)

    Mantareva, Vanya; Eneva, Ivelina; Kussovski, Vesselin; Borisova, Ekaterina; Angelov, Ivan

    2015-01-01

    The light exposure on a daily basis has been well accepted as a competitive method for decontamination of wastewater. The catalytic properties of TiO2 offer a great potential to reduce the transmission of pathogens in the environment. Although the titanium dioxide shows high activity against pathogens, its general usage in water cleaning is limited due to the insufficient excitation natural light (about 3% of the solar spectrum). A hydrophobic dodecylpyridyloxy Zn(II)-phthalocyanine with four peripheral hydrocarbon chains of C12 (ZnPcDo) was immobilized on a photocatalyst TiO2 anatase (P25). The resulted greenish colored nanoparticles of phthalocyanine were characterized by the means of absorption, fluorescence and infrared spectroscopy. The laser scanning confocal fluorescence microscopy was used to visualize the phthalocyanine dye by the red fluorescence emission (650 - 740 nm). The intensive Q-band in the far red visible spectral region (~ 690 nm) suggested a monomeric state of phthalocyanine on TiO2 nanoparticles. Two pathogenic bacterial strains (methicillin-resistant Staphylococcus aureus - MRSA and Salmonella enteritidis) associated with wastewater were photoinactivated with the suspension of the particles. The effective photoinactivation was observed with 1 g.L-1 TiO2 anatase at irradiation with UVA 364 nm as with UVA 364 nm and LED 643 nm. The gram-negative Salmonella enteritidis was fully photoinactivated with ZnPcDo-TiO2 and TiO2 alone at UVA 346 nm and at irradiation with two light sources (364 nm + 643 nm). The proposed conjugate appears as an useful composite material for antibacterial disinfection.

  7. Increased UVA exposures and decreased cutaneous Vitamin D(3) levels may be responsible for the increasing incidence of melanoma.

    PubMed

    Godar, Dianne E; Landry, Robert J; Lucas, Anne D

    2009-04-01

    Cutaneous malignant melanoma (CMM) has been increasing at a steady exponential rate in fair-skinned, indoor workers since before 1940. A paradox exists between indoor and outdoor workers because indoor workers get three to nine times less solar UV (290-400 nm) exposure than outdoor workers get, yet only indoor workers have an increasing incidence of CMM. Thus, another "factor(s)" is/are involved that increases the CMM risk for indoor workers. We hypothesize that one factor involves indoor exposures to UVA (321-400 nm) passing through windows, which can cause mutations and can break down vitamin D(3) formed after outdoor UVB (290-320 nm) exposure, and the other factor involves low levels of cutaneous vitamin D(3). After vitamin D(3) forms, melanoma cells can convert it to the hormone, 1,25-dihydroxyvitamin D(3), or calcitriol, which causes growth inhibition and apoptotic cell death in vitro and in vivo. We measured the outdoor and indoor solar irradiances and found indoor solar UVA irradiances represent about 25% (or 5-10 W/m(2)) of the outdoor irradiances and are about 60 times greater than fluorescent light irradiances. We calculated the outdoor and indoor UV contributions toward different biological endpoints by weighting the emission spectra by the action spectra: erythema, squamous cell carcinoma, melanoma (fish), and previtamin D(3). Furthermore, we found production of previtamin D(3) only occurs outside where there is enough UVB. We agree that intense, intermittent outdoor UV overexposures and sunburns initiate CMM; we now propose that increased UVA exposures and inadequately maintained cutaneous levels of vitamin D(3) promotes CMM.

  8. Synthesis and protective effects of bis{4-[N,N-di-(carboxymethyl)amino]phenoxy}alkane derivatives on UVA-induced production of MMP-1 in human skin fibroblasts.

    PubMed

    Hsu, Ling-Yih; Nien, Chih-Ying; Huang, Wei-Ming; Hsu, Shou-Che; Chang, Tsu-Chung

    2014-01-01

    UV-induced matrix metalloproteinase (MMP) production is considered a cause of skin aging. In this study, a number of novel bis{4-[N,N-di-(carboxymethyl)amino]phenoxy}alkane derivatives were synthesized and evaluated as UVA-protective agents. These compounds significantly protected human dermal fibroblast (HDF) cells from UVA-induced cytotoxicity and inhibited MMP-1 activation and expression with potency comparable to desferoxamine (DFO). Promoter activity assay indicated that they inhibited MMP-1 expression at the transcriptional level. Further studies revealed that the mechanism of these compounds may include blockage of the UVA-induced activation of the p38/mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK) pathways. Together, these results suggest that further development of these compounds may be of interest.

  9. Dermal Lipogenesis Inhibits Adiponectin Production in Human Dermal Fibroblasts while Exogenous Adiponectin Administration Prevents against UVA-Induced Dermal Matrix Degradation in Human Skin

    PubMed Central

    Fang, Chien-Liang; Huang, Ling-Hung; Tsai, Hung-Yueh; Chang, Hsin-I

    2016-01-01

    Adiponectin is one of the most abundant adipokines from the subcutaneous fat, and regulates multiple activities through endocrine, paracrine, or autocrine mechanisms. However, its expression in adipogenic induced fibroblasts, and the potential role in photoaging has not been determined. Here, human dermal fibroblasts, Hs68, were presented as a cell model of dermal lipogenesis through stimulation of adipogenic differentiation medium (ADM). Similar to other studies in murine pre-adipocyte models (i.e., 3T3-L1), Hs68 fibroblasts showed a tendency to lipogenesis based on lipid accumulation, triglyceride formation, and the expressions of PPAR-γ, lipoprotein lipase (LPL), and FABP4 mRNA. As expected, ADM-treated fibroblasts displayed a reduction on adiponectin expression. Next, we emphasized the photoprotective effects of adiponectin against UVA-induced damage in Hs68 fibroblasts. UVA radiation can downregulate cell adhesion strength and elastic modulus of Hs68 fibroblasts. Moreover, UVA radiation could induce the mRNA expressions of epidermal growth factor receptor (EGFR), adiponectin receptor 1 (AdipoR1), matrix metalloproteinase-1 (MMP-1), MMP-3, and cyclooxygenase-2 (COX-2), but downregulate the mRNA expressions of type I and type III collagen. On the other hand, post-treatment of adiponectin can partially overcome UVA-induced reduction in the cell adhesion strength of Hs68 fibroblasts through the activation of AdipoR1 and the suppression of EGF-R. In addition, post-treatment of adiponectin indicated the increase of type III collagen and elastin mRNA expression and the decrease of MMP-1 and MMP-3 mRNA expression, but a limited degree of recovery of elastic modulus on UVA-irradiated Hs68 fibroblasts. Overall, these results suggest that dermal lipogenesis may inhibit the expression of adiponectin while exogenous adiponectin administration prevents against UVA-induced dermal matrix degradation in Hs68 fibroblasts. PMID:27428951

  10. Dermal Lipogenesis Inhibits Adiponectin Production in Human Dermal Fibroblasts while Exogenous Adiponectin Administration Prevents against UVA-Induced Dermal Matrix Degradation in Human Skin.

    PubMed

    Fang, Chien-Liang; Huang, Ling-Hung; Tsai, Hung-Yueh; Chang, Hsin-I

    2016-07-14

    Adiponectin is one of the most abundant adipokines from the subcutaneous fat, and regulates multiple activities through endocrine, paracrine, or autocrine mechanisms. However, its expression in adipogenic induced fibroblasts, and the potential role in photoaging has not been determined. Here, human dermal fibroblasts, Hs68, were presented as a cell model of dermal lipogenesis through stimulation of adipogenic differentiation medium (ADM). Similar to other studies in murine pre-adipocyte models (i.e., 3T3-L1), Hs68 fibroblasts showed a tendency to lipogenesis based on lipid accumulation, triglyceride formation, and the expressions of PPAR-γ, lipoprotein lipase (LPL), and FABP4 mRNA. As expected, ADM-treated fibroblasts displayed a reduction on adiponectin expression. Next, we emphasized the photoprotective effects of adiponectin against UVA-induced damage in Hs68 fibroblasts. UVA radiation can downregulate cell adhesion strength and elastic modulus of Hs68 fibroblasts. Moreover, UVA radiation could induce the mRNA expressions of epidermal growth factor receptor (EGFR), adiponectin receptor 1 (AdipoR1), matrix metalloproteinase-1 (MMP-1), MMP-3, and cyclooxygenase-2 (COX-2), but downregulate the mRNA expressions of type I and type III collagen. On the other hand, post-treatment of adiponectin can partially overcome UVA-induced reduction in the cell adhesion strength of Hs68 fibroblasts through the activation of AdipoR1 and the suppression of EGF-R. In addition, post-treatment of adiponectin indicated the increase of type III collagen and elastin mRNA expression and the decrease of MMP-1 and MMP-3 mRNA expression, but a limited degree of recovery of elastic modulus on UVA-irradiated Hs68 fibroblasts. Overall, these results suggest that dermal lipogenesis may inhibit the expression of adiponectin while exogenous adiponectin administration prevents against UVA-induced dermal matrix degradation in Hs68 fibroblasts.

  11. Enhancement of photoprotection potential of catechin loaded nanoemulsion gel against UVA induced oxidative stress.

    PubMed

    Harwansh, Ranjit K; Mukherjee, Pulok K; Kar, Amit; Bahadur, Shiv; Al-Dhabi, Naif Abdullah; Duraipandiyan, V

    2016-07-01

    The present study was aimed to develop a catechin (CA) loaded nanoemulsion based nano-gel for the protection of skin against ultraviolet radiation (UV) induced photo-damage and to ensure its enhanced skin permeability as well as bioavailability through transdermal route. The optimized nanoemulsion (CA-NE4) was prepared by spontaneous nano-emulsification method. It was composed of oil (ethyl oleate), Smix [surfactant (span 80) and co-surfactant (transcutol CG)] and aqueous system in an appropriate ratio of 15:62:23% w/w respectively. The CA-NE4 was characterized through assessment of droplet size, zeta potential, refractive index, transmission electron microscopy (TEM), UV, high performance thin layer chromatography (HPTLC) and Fourier transform infrared spectroscopy (FTIR) analysis. The average droplet size and zeta potential of CA-NE4 were found to be 98.6±1.01nm and -27.3±0.20mV respectively. The enhanced skin permeability was better with CA-NE4 based nano-gel (CA-NG4) [96.62%] compared to conventional gel (CA-CG) [53.01%] for a period of 24h. The enhanced % relative bioavailability (F) of CA (894.73), Cmax (93.79±6.19ngmL(-1)), AUC0-t∞ (2653.99±515.02nghmL(-1)) and Tmax (12.05±0.02h) was significantly obtained with CA-NG4 as compared to oral suspension for extended periods (72h). CA-NG4 could improve the level of cutaneous antioxidant enzymes like superoxide dismutase (SOD), glutathione peroxidase (GPX) and catalase (CAT) and reduce the level of thiobarbituric acid reactive substances (TBRAS) against oxidative stress induced by UVA. Nano-gel formulation of CA showed sustained release profile and enhanced photoprotection potential due to its improved permeability as well as bioavailability (P<0.05) compared to the conventional gel. Therefore, transdermal administration of nano-gel (CA-NG4) of CA offers a better way to develop the endogenous cutaneous protection system and thus could be an effective strategy for decreasing UV-induced oxidative damage in the

  12. Design of p-type cladding layers for tunnel-injected UV-A light emitting diodes

    SciTech Connect

    Zhang, Yuewei; Krishnamoorthy, Sriram; Akyol, Fatih; Allerman, Andrew A.; Moseley, Michael W.; Armstrong, Andrew M.; Rajan, Siddharth

    2016-11-09

    Here, we discuss the engineering of p-AlGaN cladding layers for achieving efficient tunnel-injected III-Nitride ultraviolet light emitting diodes (UV LEDs) in the UV-A spectral range. We show that the capacitance-voltage measurements can be used to estimate the compensation and doping in the p-AlGaN layers located between the multi-quantum well region and the tunnel junction layer. By increasing the p-type doping concentration to overcome the background compensation, on-wafer external quantum efficiency and wall-plug efficiency of 3.37% and 1.62%, respectively, were achieved for the tunnel-injected UV LEDs emitting at 325 nm. We also show that interband tunneling hole injection can be used to realize UV LEDs without any acceptor doping. The work discussed here provides new understanding of hole doping and transport in AlGaN-based UV LEDs and demonstrates the excellent performance of tunnel-injected LEDs for the UV-A wavelength range.

  13. Design of p-type cladding layers for tunnel-injected UV-A light emitting diodes

    DOE PAGES

    Zhang, Yuewei; Krishnamoorthy, Sriram; Akyol, Fatih; ...

    2016-11-09

    Here, we discuss the engineering of p-AlGaN cladding layers for achieving efficient tunnel-injected III-Nitride ultraviolet light emitting diodes (UV LEDs) in the UV-A spectral range. We show that the capacitance-voltage measurements can be used to estimate the compensation and doping in the p-AlGaN layers located between the multi-quantum well region and the tunnel junction layer. By increasing the p-type doping concentration to overcome the background compensation, on-wafer external quantum efficiency and wall-plug efficiency of 3.37% and 1.62%, respectively, were achieved for the tunnel-injected UV LEDs emitting at 325 nm. We also show that interband tunneling hole injection can be usedmore » to realize UV LEDs without any acceptor doping. The work discussed here provides new understanding of hole doping and transport in AlGaN-based UV LEDs and demonstrates the excellent performance of tunnel-injected LEDs for the UV-A wavelength range.« less

  14. Structural, energetic, and UV-Vis spectral analysis of UVA filter 4-tert-butyl-4'-methoxydibenzoylmethane.

    PubMed

    Pinto da Silva, Luís; Ferreira, Paulo J O; Duarte, Darío J R; Miranda, Margarida S; Esteves da Silva, Joaquim C G

    2014-02-27

    The growing awareness of the harmful effects of ultraviolet (UV) solar radiation has increased the production and consumption of sunscreen products, which contain organic and inorganic molecules named UV filters that absorb, reflect, or scatter UV radiation, thus minimizing negative human health effects. 4-tert-Butyl-4'-methoxydibenzoylmethane (BMDBM) is one of the few organic UVA filters and the most commonly used. BMDBM exists in sunscreens in the enol form which absorbs strongly in the UVA range. However, under sunlight irradiation tautomerization occurs to the keto form, resulting in the loss of UV protection. In this study we have performed quantum chemical calculations to study the excited-state molecular structure and excitation spectra of the enol and keto tautomers of BMDBM. This knowledge is of the utmost importance as the starting point for studies aiming at the understanding of its activity when applied on human skin and also its fate once released into the aquatic environment. The efficiency of excitation transitions was rationalized based on the concept of molecular orbital superposition. The loss of UV protection was attributed to the enol → keto phototautomerism and subsequent photodegradation. Although this process is not energetically favorable in the singlet bright state, photodegradation is possible because of intersystem crossing to the first two triplet states.

  15. Highly sensitive UVA and violet photodetector based on single-layer graphene-TiO2 heterojunction.

    PubMed

    Liang, Feng-Xia; Zhang, Deng-Yue; Wang, Jiu-Zhen; Kong, Wei-Yu; Zhang, Zhi-Xiang; Wang, Yi; Luo, Lin-Bao

    2016-11-14

    A highly sensitive ultraviolet A (UVA) and violet photodetector based on p-type single-layer graphene (SLG)-TiO2 heterostructure was fabricated by transferring chemical vapor deposition derived SLG on the surface of commercial single-crystal TiO2 wafer. Optoelectronic analysis reveals the as-fabricated Schottky junction PD was highly sensitive to light illumination in UVA and violet range, with peak sensitivity at 410 nm and excellent stability and reproducibility, but virtually blind to illumination with wavelength less than 350 nm or more than 460 nm. The on/off ratio of the device was calculated to be 6.8 × 104, which is better than the majority of previously reported TiO2 based PDs. What is more, the rise/fall time were estimated to be 0.74/1.18 ms, much faster than other TiO2 based counterparts. The totality of the above result signifies that the present SLG-TiO2 Schottky junction photodetector may have promising application in future high-speed, high-sensitivity optoelectronic nanodevices and systems.

  16. Characterization of carotenoids in soil bacteria and investigation of their photodegradation by UVA radiation via resonance Raman spectroscopy.

    PubMed

    Kumar B N, Vinay; Kampe, Bernd; Rösch, Petra; Popp, Jürgen

    2015-07-07

    A soil habitat consists of an enormous number of pigmented bacteria with the pigments mainly composed of diverse carotenoids. Most of the pigmented bacteria in the top layer of the soil are photoprotected from exposure to huge amounts of UVA radiation on a daily basis by these carotenoids. The photostability of these carotenoids depends heavily on the presence of specific features like a carbonyl group or an ionone ring system on its overall structure. Resonance Raman spectroscopy is one of the most sensitive and powerful techniques to detect and characterize these carotenoids and also monitor processes associated with them in their native system at a single cell resolution. However, most of the resonance Raman profiles of carotenoids have very minute differences, thereby making it extremely difficult to confirm if these differences are attributed to the presence of different carotenoids or if it is a consequence of their interaction with other cellular components. In this study, we devised a method to overcome this problem by monitoring also the photodegradation of the carotenoids in question by UVA radiation wherein a differential photodegradation response will confirm the presence of different carotenoids irrespective of the proximities in their resonance Raman profiles. Using this method, the detection and characterization of carotenoids in pure cultures of five species of pigmented coccoid soil bacteria is achieved. We also shed light on the influence of the structure of the carotenoid on its photodegradation which can be exploited for use in the characterization of carotenoids via resonance Raman spectroscopy.

  17. Synthesis, characterization and photocatalytic properties of SnO2-ZnO composite under UV-A light.

    PubMed

    Kuzhalosai, V; Subash, B; Senthilraja, A; Dhatshanamurthi, P; Shanthi, M

    2013-11-01

    The SnO2 loaded ZnO (SnO2-ZnO) was successfully synthesized by precipitation-decomposition method. The catalyst was characterized by X-ray diffraction (XRD), high resolution scanning electron microscope (HR-SEM) images, energy dispersive spectrum (EDS), diffuse reflectance spectra (DRS), photoluminescence spectra (PL) and BET surface area measurements. The photocatalytic activity of SnO2-ZnO was investigated for the degradation of Acid Orange 10 (AO 10) in aqueous solution using UV-A light. SnO2-ZnO is found to be more efficient than commercial ZnO, bare ZnO, TiO2-P25 and TiO2 (Merck) at pH 12 for the mineralization of AO 10 dye. The effects of operational parameters such as the amount of photocatalyst, dye concentration, initial pH on photo mineralization of AO 10 dye have been analyzed. The mineralization of AO 10 has been confirmed by chemical oxygen demand (COD) measurements. A degradation mechanism is proposed for the degradation of AO 10 with SnO2-ZnO under UV-A light. This catalyst is found to be reusable.

  18. Preillumination of lettuce seedlings with red light enhances the resistance of photosynthetic apparatus to UV-A.

    PubMed

    Kreslavski, Vladimir D; Lyubimov, Valery Yu; Shirshikova, Galina N; Shmarev, Alexander N; Kosobryukhov, Anatoly A; Schmitt, Franz-Josef; Friedrich, Thomas; Allakhverdiev, Suleyman I

    2013-05-05

    Seedlings of 10-day-old lettuce (Lactuca sativa L., cultivar Berlin) were preilluminated by low intensity red light (λmax=660 nm, 10 min, 5 μmol quanta m(-2) s(-1)) and far-red light (λmax=730 nm, 10 min, 5 μmol quanta m(-2) s(-1)) to study the effect of pre-treatment on photosynthesis, photochemical activity of photosystem II (PSII), the contents of photosynthetic and UV-A-absorbing pigments (UAPs) and H2O2, as well as total and ascorbate peroxidase activities in cotyledonary leaves of seedlings exposed to UV-A. UV radiation reduced the photosynthetic rate (Pn), the activity of PSII, and the contents of Chl a and b, carotenoids and UAPs in the leaves, but increased the content of H2O2 and the total peroxidase activity. Preillumination with red light removed these effects of UV. In turn, the illumination with red light, then far-red light removed the effect of the red light. Illumination with red light alone increased the content of UAPs, as well as peroxidase activity. It is suggested that higher resistance of the lettuce photosynthetic apparatus to UV-A radiation is associated with involvement of the active form of phytochrome B, thereby increasing peroxidase activities as well as UAPs and saving preservation of photosynthetic pigment contents due to pre-illumination with red light.

  19. Oxidation of sulfamethoxazole by UVA radiation and modified Fenton reagent: toxicity and biodegradability of by-products.

    PubMed

    Marciocha, D; Kalka, J; Turek-Szytow, J; Wiszniowski, J; Surmacz-Górska, J

    2009-01-01

    Improvement of sulfamethoxazole (4-amino-N-(5-methylisoxazol-3-yl)-benzenesulfonamide-SMX) biodegradability using a modified Fenton's reaction has been studied. The modification consists of replacing hydrogen peroxide with atmospheric air and adding copper sulphate as a reaction promoter. Two series of experiments were carried out. The first (Series 1) was conducted using only the catalysts with aeration. In the second series (Series 2), cycles of UVA radiation and aeration were used. During UVA radiation, the removal of sulfamethoxazole proceeds less rapidly than in only aerated solution. After 1.5 h of these two processes, the SMX degradation was 23% in Series 2 and 59% in Series 1. The opposite trend was observed for mineralization and the removal of DOC was about 5% higher in Series 2 than in Series 1. The FTIR spectra of the extracts of reaction products yielded by four organic solvents of varying polarity revealed a wide diversity of functional groups in the post-reaction mixture in comparison to the extracts from sulfamethoxazole solution. Based on FTIR analysis, several oxidation products of sulfamethoxazole are proposed. Apparently, hydroxyl radicals initially attack sulphonamide bonds, resulting in the formation of sulfanilic acid and 3-amino-5-methylisoxazole. Irrespective of the reference organism used in toxicity tests, the post-reaction mixture in the Series 2 was more toxic than the post-reaction mixture in Series 1. In contrast, the biodegradability calculated as BOD(5)/DOC ratio, was higher for post-reaction mixture 2 and amounted to 0.43.

  20. A Focus on Quality and Safety Traits of Saccharomyces cerevisiae Isolated from Uva di Troia Grape Variety.

    PubMed

    Petruzzi, Leonardo; Bevilacqua, Antonio; Corbo, Maria Rosaria; Speranza, Barbara; Capozzi, Vittorio; Sinigaglia, Milena

    2017-01-01

    The aim of this work was to study Saccharomyces cerevisiae strains isolated from vineyards of the autochthonous grape variety "Uva di Troia" located in different geographical areas of Apulian region (Southern Italy). Four hundred isolates were studied in relation to H2 S production, β-glucosidase activity, and pigments adsorption from grape skin. Thus, 81 isolates were selected, identified through the amplification of the interdelta region, and grouped in 19 biotypes (from I to XIX). The enological performances were assessed to determine the content of residual sugars, ethanol, glycerol, and volatile acidity, after a microfermentation in Uva di Troia must for each isolate. The ability to remove ochratoxin A (OTA) was studied as an additional tool to select promising strains. A geographical-dependent technological variability was found for glycerol and volatile acidity, suggesting that the different indigenous yeasts can have a peculiar impact on the final characteristics of the corresponding wine ("Nero di Troia"). Only 2 biotypes (VI and XVII) were able to remove OTA throughout fermentation, with the highest reduction achieved by the biotype XVII (ca. 30%).

  1. Photocatalytic antibacterial effects on TiO2-anatase upon UV-A and UV-A/VIS threshold irradiation.

    PubMed

    Wu, Yanyun; Geis-Gerstorfer, Jürgen; Scheideler, Lutz; Rupp, Frank

    2016-01-01

    Photocatalysis mediated by the anatase modification of titanium dioxide (TiO2) has shown antibacterial effects in medical applications. The aim of this study was to investigate the possibility of expanding the excitation wavelengths for photocatalytic antibacterial effects from ultraviolet (UV) into the visible light range. After deposition of salivary pellicle and adhesion of Streptococcus gordonii on anatase, different irradiation protocols were applied to induce photocatalysis: ultraviolet A (UV-A) > 320 nm; ultraviolet/visible (UV-A/VIS) light > 380 nm and > 390 nm; and VIS light 400-410 nm. A quartz crystal microbalance with dissipation (QCM-D) tests and microscopic examination were used to observe the photoinduced antibacterial effects. Salivary pellicle could be photocatalytically decomposed under all irradiation protocols. In contrast, effective photocatalytic attack of bacteria could be observed by UV-A as well as by UV-A/VIS at 380 nm < λ < 390 nm only. Wavelengths above 380 nm show promise for in situ therapeutic antifouling applications.

  2. Effect of UV-A radiation as an environmental stress on the development, longevity, and reproduction of the oriental armyworm, Mythimna separata (Lepidoptera: Noctuidae).

    PubMed

    Ali, Arif; Rashid, Muhammad Adnan; Huang, Qiu Ying; Lei, Chao-Liang

    2016-09-01

    The ultraviolet light (UV-A) range of 320-400 nm is widely used as light trap for insect pests. Present investigation was aimed to determine the effect of UV light-A radiation on development, adult longevity, reproduction, and development of F1 generation of Mythimna separata. Our results revealed that the mortality of the second instar larvae was higher than the third and fourth instar larvae after UV-A radiation. As the time of UV-A irradiation for pupae prolonged, the rate of adult emergence reduced. Along with the extension of radiation time decreased the longevity of adult females and males. However, the radiation exposure of 1 and 4 h/day increased fecundity of female adults, and a significant difference was observed in a 1 h/day group. The oviposition rates of female adults in all the treatments were significantly higher than the control. In addition, UV-A radiation treatments resulted in declined cumulative survival of F1 immature stages (eggs, larvae, and pupae). After exposure time of 4 and 7 h/day, the developmental periods of F1 larvae increased significantly, but no significant effects on F1 pupal period were recorded.

  3. ROS production in homogenate from the body wall of sea cucumber Stichopus japonicus under UVA irradiation: ESR spin-trapping study.

    PubMed

    Qi, Hang; Dong, Xiu-fang; Zhao, Ya-ping; Li, Nan; Fu, Hui; Feng, Ding-ding; Liu, Li; Yu, Chen-xu

    2016-02-01

    Sea cucumber Stichopus japonicus (S. japonicus) shows a strong ability of autolysis, which leads to severe deterioration in sea cucumber quality during processing and storage. In this study, to further characterize the mechanism of sea cucumber autolysis, hydroxyl radical production induced by ultraviolet A (UVA) irradiation was investigated. Homogenate from the body wall of S. japonicas was prepared and subjected to UVA irradiation at room temperature. Electron Spin Resonance (ESR) spectra of the treated samples were subsequently recorded. The results showed that hydroxyl radicals (OH) became more abundant while the time of UVA treatment and the homogenate concentration were increased. Addition of superoxide dismutase (SOD), catalase, EDTA, desferal, NaN3 and D2O to the homogenate samples led to different degrees of inhibition on OH production. Metal cations and pH also showed different effects on OH production. These results indicated that OH was produced in the homogenate with a possible pathway as follows: O2(-) → H2O2 → OH, suggesting that OH might be a critical factor in UVA-induced S. japonicus autolysis.

  4. Nanostructured lipid carriers loaded with CoQ10: effect on human dermal fibroblasts under normal and UVA-mediated oxidative conditions.

    PubMed

    Brugè, Francesca; Damiani, Elisabetta; Puglia, Carmelo; Offerta, Alessia; Armeni, Tatiana; Littarru, Gian Paolo; Tiano, Luca

    2013-10-15

    Nanostructured lipid carriers (NLC) represent an emerging tool for drug delivery and are characterized by important features which promote increased bioavailability and epithelial penetration of lipophilic compounds. However, despite these advantages, their potential cytotoxicity should not be underestimated, especially under in vivo usage conditions. Here we analyzed the viability, intracellular reactive oxygen species (ROS), oxidative DNA damage and mitochondrial functionality in human dermal fibroblasts (HDF) in the presence of NLC either empty or loaded with the reduced or oxidized form of Coenzyme Q10. Experiments were carried out under standard culture conditions and under oxidative stress induced by UVA irradiation, where the latter treatment significantly affected all the endpoints tested above compared to the non-UVA condition. The data show that NLC alone, whether exposed or not exposed to UVA, produce a slight, though significant decrease in cell viability associated with enhanced oxidative stress, which did not however lead to oxidative DNA damage nor mitochondrial impairment. Reduced CoQ10-NLC, differently from oxidized CoQ10-NLC, were able to efficiently counteract UVA-associated mitochondrial depolarization suggesting a potential role of this molecule in antiageing cosmetological formulations. In conclusion, our results suggest that interactions of NLC with cells and biomolecules should be routinely assessed for understanding their compatibility and toxicity, not only under normal conditions, but also under any chemical or physical stress which these delivery systems might be subjected to during their employment.

  5. UVA exposure of human skin reconstructed in vitro induces apoptosis of dermal fibroblasts: subsequent connective tissue repair and implications in photoaging.

    PubMed

    Bernerd, F; Asselineau, D

    1998-09-01

    The skin reconstructed in vitro has been previously shown to be a useful model to investigate the effects of UVB exposure (Bernerd and Asselineau, 1997). The present study describes the response to UVA irradiation. Major alterations were observed within the dermal compartment. Apoptosis of fibroblasts located in the superficial area of the dermal equivalent was observed as soon as 6 h after irradiation, leading to their disappearance after 48 h. This effect was obtained without major alterations of epidermal keratinocytes suggesting a differential cell type sensitivity to UVA radiations. In addition, collagenase I was secreted by dermal fibroblasts. The UVA dermal effects could be observed even after removal of the epidermis during the post irradiation period, demonstrating that they were independent of the keratinocyte response. The analysis of the tissue regeneration during the following 2 weeks revealed a connective tissue repair via fibroblasts proliferation, migration and active synthesis of extracellular matrix proteins such as fibronectin and procollagen I. This cellular recolonization of the superficial part of the dermal equivalent was due to activation of surviving fibroblasts located deeply in the dermal equivalent. The direct damage in the dermis and the subsequent connective tissue repair may contribute to the formation of UVA-induced dermal alterations.

  6. DNA repair kinetic of hydrogen peroxide and UVA/B induced lesions in peripheral blood leucocytes from xeroderma pigmentosum patients and healthy subjects.

    PubMed

    Gonzalez, Elio A Prieto; Mudry, Marta D; Palermo, Ana Maria

    2014-01-01

    The objective of the present work was to study the fine kinetics of DNA repair in xeroderma pigmentosum (XP) syndrome, a complex disorder linked to a deficiency in repair that increases cancer susceptibility. The repair process was evaluated by the comet assay (CA) in cells from 2 XP patients and 9 controls exposed to UVA/B (UVA 366/UVB 280 nm) and H2O2 (150 μM) at temperatures of 4, 15, and 37°C. Samples were taken at 2-min intervals during the first 10 min to analyze the "fine kinetics" repair during the initial phase of the curve, and then at 15, 20, 25, 30, 45, 60, and 120 min. CA evaluation of DNA repair activity points to BER/NER initiation in the first 30 min with both inductors at 37°C and 15°C, but final comet length showed differences according to treatment. Repair kinetics during 120 min showed a good correlation with clinical features in both XP patients. Differences in final comet length were less pronounced in XP cells treated with H2O2 than with UVA/B, probably because the peroxide produces mainly base oxidation but less bulky lesions; UVA/B generates a mixture of both. These findings reinforce the value of CA in testing in DNA repair ability or exposure monitoring.

  7. Epidermal UV-A absorbance and whole-leaf flavonoid composition in pea respond more to solar blue light than to solar UV radiation.

    PubMed

    Siipola, Sari M; Kotilainen, Titta; Sipari, Nina; Morales, Luis O; Lindfors, Anders V; Robson, T Matthew; Aphalo, Pedro J

    2015-05-01

    Plants synthesize phenolic compounds in response to certain environmental signals or stresses. One large group of phenolics, flavonoids, is considered particularly responsive to ultraviolet (UV) radiation. However, here we demonstrate that solar blue light stimulates flavonoid biosynthesis in the absence of UV-A and UV-B radiation. We grew pea plants (Pisum sativum cv. Meteor) outdoors, in Finland during the summer, under five types of filters differing in their spectral transmittance. These filters were used to (1) attenuate UV-B; (2) attenuate UV-B and UV-A < 370 nm; (3) attenuate UV-B and UV-A; (4) attenuate UV-B, UV-A and blue light; and (5) as a control not attenuating these wavebands. Attenuation of blue light significantly reduced the flavonoid content in leaf adaxial epidermis and reduced the whole-leaf concentrations of quercetin derivatives relative to kaempferol derivatives. In contrast, UV-B responses were not significant. These results show that pea plants regulate epidermal UV-A absorbance and accumulation of individual flavonoids by perceiving complex radiation signals that extend into the visible region of the solar spectrum. Furthermore, solar blue light instead of solar UV-B radiation can be the main regulator of phenolic compound accumulation in plants that germinate and develop outdoors.

  8. Enhanced inactivation of E. coli and MS-2 phage by silver ions combined with UV-A and visible light irradiation.

    PubMed

    Kim, Jee Yeon; Lee, Changha; Cho, Min; Yoon, Jeyong

    2008-01-01

    Silver ions have been widely used as an effective water disinfectant or antimicrobial material for many decades. In addition, the application of silver ions in combination with other biocides, especially UV(254) (UV-C) irradiation, was reported to be effective in enhancing its germicidal activity. However, it is not yet known how UV-A (300-400 nm) or visible light irradiation, which have little or no antimicrobial activities, affect microorganism inactivation by silver ions. This study newly reports that the inactivation efficiencies of Escherichia coli and MS-2 phage by silver ions were significantly enhanced by UV-A or visible light irradiation. UV-A irradiation enhanced the inactivation of E. coli and MS-2 phage by 3.0 and 2.5 log/30 min, respectively, as compared with the simple summated value of individual applications of silver ions and UV-A. A similar trend was observed with visible light irradiation (>400 nm) although the level of enhancement was lessened. The photochemical reaction of silver-cysteine complex was suggested as a possible mechanism for this enhancement. Spectrophotometric and MALDI-TOF mass analyses support the fact that silver ions coupled with light irradiation causes critical cell damage through the complexation of silver ions with thiol (-SH) groups in structural or enzymatic proteins of the microorganisms and their subsequent photochemical destruction.

  9. Roles of reactive oxygen species in UVA-induced oxidation of 5,6-dihydroxyindole-2-carboxylic acid-melanin as studied by differential spectrophotometric method.

    PubMed

    Ito, Shosuke; Kikuta, Marina; Koike, Shota; Szewczyk, Grzegorz; Sarna, Michal; Zadlo, Andrzej; Sarna, Tadeusz; Wakamatsu, Kazumasa

    2016-05-01

    Eumelanin photoprotects pigmented tissues from ultraviolet (UV) damage. However, UVA-induced tanning seems to result from the photooxidation of preexisting melanin and does not contribute to photoprotection. We investigated the mechanism of UVA-induced degradation of 5,6-dihydroxyindole-2-carboxylic acid (DHICA)-melanin taking advantage of its solubility in a neutral buffer and using a differential spectrophotometric method to detect subtle changes in its structure. Our methodology is suitable for examining the effects of various agents that interact with reactive oxygen species (ROS) to determine how ROS is involved in the UVA-induced oxidative modifications. The results show that UVA radiation induces the oxidation of DHICA to indole-5,6-quinone-2-carboxylic acid in eumelanin, which is then cleaved to form a photodegraded, pyrrolic moiety and finally to form free pyrrole-2,3,5-tricarboxylic acid. The possible involvement of superoxide radical and singlet oxygen in the oxidation was suggested. The generation and quenching of singlet oxygen by DHICA-melanin was confirmed by direct measurements of singlet oxygen phosphorescence.

  10. 1H NMR characterization of the intermediate formed upon UV-A excitation of biopterin, neopterin and 6-hydroxymethylpterin in O 2-free aqueous solutions

    NASA Astrophysics Data System (ADS)

    Vignoni, Mariana; Salum, M. Laura; Erra-Balsells, Rosa; Thomas, Andres H.; Cabrerizo, Franco M.

    2010-01-01

    Pterins belong to a family of heterocyclic compounds present in a wide range of living systems and participate in relevant biological functions. Under anaerobic conditions, the unstable red intermediate generated by UV-A irradiation of biopterin, neopterin and 6-hydroxymethylpterin was identified by 1H NMR analysis, in alkaline D 2O solutions, as 5,8-dihydro-6-formylpterin.

  11. Effects of ultraviolet radiation (UVA+UVB) on young gametophytes of Gelidium floridanum: growth rate, photosynthetic pigments, carotenoids, photosynthetic performance, and ultrastructure.

    PubMed

    Simioni, Carmen; Schmidt, Eder C; Felix, Marthiellen R de L; Polo, Luz Karime; Rover, Ticiane; Kreusch, Marianne; Pereira, Debora T; Chow, Fungyi; Ramlov, Fernanda; Maraschin, Marcelo; Bouzon, Zenilda L

    2014-01-01

    This study investigated the effects of radiation (PAR+UVA+UVB) on the development and growth rates (GRs) of young gametophytes of Gelidium floridanum. In addition, photosynthetic pigments were quantified, carotenoids identified, and photosynthetic performance assessed. Over a period of 3 days, young gametophytes were cultivated under laboratory conditions and exposed to photosynthetically active radiation (PAR) at 80 μmol photons m(-2) s(-1) and PAR+UVA (0.70 W m(-2))+UVB (0.35 W m(-2)) for 3 h per day. The samples were processed for light and electron microscopy to analyze the ultrastructure features, as well as carry out metabolic studies of GRs, quantify the content of photosynthetic pigments, identify carotenoids and assess photosynthetic performance. PAR+UVA+UVB promoted increase in cell wall thickness, accumulation of floridean starch grains in the cytoplasm and disruption of chloroplast internal organization. Algae exposed to PAR+UVA+UVB also showed a reduction in GR of 97%. Photosynthetic pigments, in particular, phycoerythrin and allophycocyanin contents, decreased significantly from UV radiation exposure. This result agrees with the decrease in photosynthetic performance observed after exposure to ultraviolet radiation, as measured by a decrease in the electron transport rate (ETR), where values of ETRmax declined approximately 44.71%. It can be concluded that radiation is a factor that affects the young gametophytes of G. floridanum at this stage of development.

  12. Dermato-protective properties of ergothioneine through induction of Nrf2/ARE-mediated antioxidant genes in UVA-irradiated Human keratinocytes.

    PubMed

    Hseu, You-Cheng; Lo, Heng-Wei; Korivi, Mallikarjuna; Tsai, Yu-Cheng; Tang, Meng-Ju; Yang, Hsin-Ling

    2015-09-01

    UVA irradiation-induced skin damage and redox imbalance have been shown to be ameliorated by ergothioneine (EGT), a naturally occurring sulfur-containing amino acid. However, the responsible molecular mechanism with nanomolar concentrations of EGT remains unclear. We investigated the dermato protective efficacies of EGT (125-500nM) against UVA irradiation (15J/cm(2)), and elucidated the underlying molecular mechanism in human keratinocyte-derived HaCaT cells. We found that EGT treatment prior to UVA exposure significantly increased the cell viability and prevented lactate dehydrogenase release into the medium. UVA-induced ROS and comet-like DNA formation were remarkably suppressed by EGT with a parallel inhibition of apoptosis, as evidenced by reduced DNA fragmentation (TUNEL), caspase-9/-3 activation, and Bcl-2/Bax dysregulation. Furthermore, EGT alleviated UVA-induced mitochondrial dysfunction. Dose-dependent increases of antioxidant genes, HO-1, NQO-1, and γ-GCLC and glutathione by EGT were associated with upregulated Nrf2 and downregulated Keap-1 expressions. This was confirmed by increased nuclear accumulation of Nrf2 and inhibition of Nrf2 degradation. Notably, augmented luciferase activity of ARE may explain Nrf2/ARE-mediated signaling pathways behind EGT dermato-protective properties. We further demonstrated that Nrf2 translocation was mediated by PI3K/AKT, PKC, or ROS signaling cascades. This phenomenon was confirmed with suppressed nuclear Nrf2 activation, and consequently diminished antioxidant genes in cells treated with respective pharmacological inhibitors (LY294002, GF109203X, and N-acetylcysteine). Besides, increased basal ROS by EGT appears to be crucial for triggering the Nrf2/ARE signaling pathways. Silencing of Nrf2 or OCTN1 (EGT carrier protein) signaling with siRNA showed no such protective effects of EGT against UVA-induced cell death, ROS, and apoptosis, which is evidence of the vitality of Nrf2 translocation and protective efficacy of EGT

  13. Enhanced Antimicrobial Activity Based on a Synergistic Combination of Sub-Lethal Levels of Stresses Induced by UV-A Light and Organic Acids.

    PubMed

    de Oliveira, Erick F; Cossu, Andrea; Tikekar, Rohan V; Nitin, Nitin

    2017-03-31

    Reduction of microbial load in food and water systems is critical for their safety and shelf-life. Conventionally, physical processes such as heat or light are used for rapid inactivation of microbes, while natural compounds such as lactic acid may be used as preservatives after the initial physical process. This study demonstrates enhanced and rapid inactivation of bacteria based on a synergistic combination of sub-lethal levels of stresses induced by UV-A light and two food grade organic acids. A 4.7 ± 0.5 log CFU/mL reduction in E.coli O157:H7 was observed using a synergistic combination of UV-A light, gallic acid (GA) and lactic acid (LA), while the individual treatments and the combination of individual organic acids with UV-A light resulted in less than one log CFU/mL reduction. Enhanced inactivation of bacteria on the surface of lettuce and spinach was also observed based on the synergistic combination. Mechanistic investigations suggested that the synergistic combination of GA+LA+UVA treatment resulted in a significant increase in membrane permeation and intracellular thiol oxidation and affected the metabolic machinery of E. coli In addition, the antimicrobial activity of the synergistic combination of GA+LA+UVA treatment was only effective against metabolic active E.coli O157:H7. In summary, this study illustrates the potential of simultaneously using a combination of sub-lethal concentration of natural antimicrobials and low level of physical stress in the form of UV-A light to inactivate bacteria in water and food systems.IMPORTANCE There is critical unmet need to improve microbial safety of food supply, while retaining optimal nutritional and sensory properties of food. Furthermore, there is need to develop novel technologies that can reduce the impact of food processing operations on energy and water resources. Conventionally, physical processes such as heat and light are used for inactivation of microbes in food products, but these processes often

  14. Tropical high-altitude Andean lakes located above the tree line attenuate UV-A radiation more strongly than typical temperate alpine lakes.

    PubMed

    Aguilera, Ximena; Lazzaro, Xavier; Coronel, Jorge S

    2013-09-01

    Tropical high-altitude Andean lakes are physically harsh ecosystems. Located above the treeline (≥4000 m a.s.l.), they share common features with temperate alpine lakes, which impose extreme conditions on their aquatic organisms: e.g., strong winds, broad diel variations in water temperature, and intense solar ultraviolet radiation (UVR). However, because of their latitude, they differ in two major ecological characteristics: they lack ice cover during the winter and they do not present summer water column stratification. We sampled 26 tropical high-altitude Andean lakes from three regions of the Bolivian Eastern Andes Cordillera during the wet period (austral summer). We performed an ordination to better describe the typology of Andean lakes in relation to the environmental variables, and we assessed the relationships among them, focussing on the UV-A transparency (360 nm) throughout the water column. We found a positive correlation between UV-A transparency calculated as Z(1%) (the depth which reaches 1% of the surface UV-A), the lake maximum depth and Secchi transparency (r = 0.61). Z(1%) of UV-A was smaller in shallow lakes than in deep lakes, indicating that shallow lakes are less transparent to UV-A than deep lakes. We hypothesize that, compared to shallow lakes, deep lakes (maximum depth > 10 m) may have lower dissolved organic carbon (DOC) concentrations (that absorb UV radiation) due to lower temperature and reduced macrophyte cover. Based on our data, tropical high-altitude Andean lakes are less transparent to UV-A (K(d) range = 1.4-11.0 m(-1); Z(1%) depth range = 0.4-3.2 m) than typical temperate alpine lakes (1-6 m(-1), 3-45 m, respectively). Moreover, they differ in vertical profiles of UV-A, chlorophyll-a, and temperature, suggesting that they may have a distinct ecological functioning. Such peculiarities justify treating tropical high-altitude Andean lakes as a separate category of alpine lakes. Tropical high-altitude Andean lakes have been poorly

  15. Induction of bystander effects by UVA, UVB, and UVC radiation in human fibroblasts and the implication of reactive oxygen species.

    PubMed

    Widel, Maria; Krzywon, Aleksandra; Gajda, Karolina; Skonieczna, Magdalena; Rzeszowska-Wolny, Joanna

    2014-03-01

    Radiation-induced bystander effects are various types of responses displayed by nonirradiated cells induced by signals transmitted from neighboring irradiated cells. This phenomenon has been well studied after ionizing radiation, but data on bystander effects after UV radiation are limited and so far have been reported mainly after UVA and UVB radiation. The studies described here were aimed at comparing the responses of human dermal fibroblasts exposed directly to UV (A, B, or C wavelength range) and searching for bystander effects induced in unexposed cells using a transwell co-incubation system. Cell survival and apoptosis were used as a measure of radiation effects. Additionally, induction of senescence in UV-exposed and bystander cells was evaluated. Reactive oxygen species (ROS), superoxide radical anions, and nitric oxide inside the cells and secretion of interleukins 6 and 8 (IL-6 and IL-8) into the medium were assayed and evaluated as potential mediators of bystander effects. All three regions of ultraviolet radiation induced bystander effects in unexposed cells, as shown by a diminution of survival and an increase in apoptosis, but the pattern of response to direct exposure and the bystander effects differed depending on the UV spectrum. Although UVA and UVB were more effective than UVC in generation of apoptosis in bystander cells, UVC induced senescence both in irradiated cells and in neighbors. The level of cellular ROS increased significantly shortly after UVA and UVB exposure, suggesting that the bystander effects may be mediated by ROS generated in cells by UV radiation. Interestingly, UVC was more effective at generation of ROS in bystanders than in directly exposed cells and induced a high yield of superoxide in exposed and bystander cells, which, however, was only weakly associated with impairment of mitochondrial membrane potential. Increasing concentration of IL-6 but not IL-8 after exposure to each of the three bands of UV points to its role

  16. Effects of UVA1 Phototherapy on Expression of Human Endogenous Retroviral Sequence (HERV)-K10 gag in Morphea: A Preliminary Study

    PubMed Central

    Kowalczyk, Michał Jacek; Teresiak-Mikołajczak, Ewa; Dańczak-Pazdrowska, Aleksandra; Żaba, Ryszard; Adamski, Zygmunt; Osmola-Mańkowska, Agnieszka

    2017-01-01

    Background Morphea, also known as localized scleroderma, is a rare autoimmune connective tissue disease characterized by skin fibrosis. UVA1 phototherapy is an important asset in the reduction of clinical manifestations in morphea. There are studies claiming that UV light modulates the expression of some human endogenous retroviral sequences. The aim of this study was to determine if the expression of HERV-K10 gag element is lowered by UVA1 phototherapy in morphea, a disease in which such irradiation has a soothing effect. Material/Methods The expression levels of the HERV-K10 gag were assessed by real-time PCR (polymerase chain reaction) in peripheral blood mononuclear cells (PBMC) and skin-punch biopsies of healthy volunteers and 9 morphea patients before and after phototherapy. Additionally, correlations between the HERV-K10 gag expression and age, disease duration, the Localized Scleroderma Skin Severity Index (LoSSI), and antinuclear antibody (ANA) titers were assessed. Results In PBMC, HERV-K10 gag mRNA was significantly elevated after UVA1 phototherapy compared to healthy controls. Most of the patients responded with an increased expression level of this sequence. However, we found no statistical evidence at this point that phototherapy indeed has an effect on the HERV-K10 gag expression (there were no statistical differences in PBMC of morphea patients before and after phototherapy). Similarly, there was no statistically relevant effect of the UVA1 on the expression of HERV-K10 gag in skin. Conclusions At this point, the effect of UVA1 phototherapy on the expression of HERV-K10 gag cannot be statistically confirmed. PMID:28130554

  17. Synergistic effect of the combination of immobilized TiO2, UVA and ozone on the decomposition of dichloroacetic acid.

    PubMed

    Mehrjouei, Mohammad; Müller, Siegfried; Möller, Detlev

    2012-01-01

    The performance of a heterogeneous photocatalytic ozonation system (TiO(2)/UVA/O(3)) was evaluated on the degradation and mineralization of dichloroacetic acid as a contaminant in aqueous solutions by means of a planar reactor. The commercial product "Pilkington Active™ glass" was used as the immobilized TiO(2) photocatalyst and it was irradiated by near UV light in this study. The synergistic interaction between ozone and the photoactivated TiO(2) surface was discussed and highlighted. Furthermore, the influences of initial concentration and temperature on the degradation rate of dichloroacetic acid and the ozone consumption level during the oxidation process were investigated. The concentrations of dichloroacetic acid and chloride anions produced during degradation were measured using ion chromatography. The mineralization of dichloroacetic acid was evaluated by Total Organic Carbon (TOC) measurements. The degradation of dichloroacetic acid by photocatalytic ozonation showed good agreement with the kinetics of first-order reactions with respect to dichloroacetic acid.

  18. Kinetics of (/sup 14/C-5) 8-methoxypsoralen uptake by UVA irradiated and non-irradiated rabbit eye tissues

    SciTech Connect

    Malinin, G.I.; Glew, W.B.; Roberts, W.P.; Nigra, T.P.

    1981-05-01

    Total 8-methoxypsoralen (8-MOP) in intact and UVA irradiated rabbit eye tissues and its unaltered fraction in aqueous and eye lenses were determined over the 24 hours after i.v. injection of (/sup 14/C-5) and carrier 8-MOP at the concentration of 50 microCi and 5 mg/kg. No 8-MOP was detected at the end of 24 hours in intact and irradiated aqueous, vitreous and retina in contrast to one hour when the respective levels were congruent to 220, greater than 0 and congruent to 160 ng/g. Eye-plasma drug concentration ratios were less than 0.5 initially, but increased thereafter. While the average lens 8-MOP levels of congruent to 140 ng/g remained unchanged for 24 hours, no unaltered drug was detected beyond eight hours. Measurable amounts of label at the end of 24 hours also persisted in the cornea, iris, sclera and conjunctiva.

  19. Heterogeneous uptake of NO2 on Arizona Test Dust under UV-A irradiation: An aerosol flow tube study

    NASA Astrophysics Data System (ADS)

    Dupart, Yoan; Fine, Ludovic; D'Anna, Barbara; George, Christian

    2014-12-01

    The uptake rate of NO2 on Arizona Test Dust aerosols was measured using an aerosol flow tube (AFT). While the uptake rate in the dark could not be measured, the uptake under UV-A irradiation was enhanced, with values in the range from (0.6 ± 0.3) × 10-8, (2.4 ± 0.4) × 10-8. The observed gas phase products were HONO and NO, with yields of at 30% and 9.6%, respectively. The difference between these measurements and those previously reported on macroscopic films are discussed and differences highlighted. Interestingly, a reasonable agreement is observed between the uptake kinetics of NO2 on Arizona Test Dust macroscopic films and aerosols, despite the different experimental approaches. The simplest approach i.e. thin films having a significant porosity, provides similar uptake kinetics to the more complex and realistic AFT approach.

  20. NASA-UVa light aerospace alloy and structures technology program supplement: Aluminum-based materials for high speed aircraft

    NASA Technical Reports Server (NTRS)

    Starke, E. A., Jr. (Editor)

    1995-01-01

    This report on the NASA-UVa light aerospace alloy and structure technology program supplement: Aluminum-Based Materials for High Speed Aircraft covers the period from July 1, 1992. The objective of the research is to develop aluminum alloys and aluminum matrix composites for the airframe which can efficiently perform in the HSCT environment for periods as long as 60,000 hours (certification for 120,000 hours) and, at the same time, meet the cost and weight requirements for an economically viable aircraft. Current industry baselines focus on flight at Mach 2.4. The research covers four major materials systems: (1) Ingot metallurgy 2XXX, 6XXX, and 8XXX alloys, (2) Powder metallurgy 2XXX alloys, (3) Rapidly solidified, dispersion strengthened Al-Fe-X alloys, and (4) Discontinuously reinforced metal matrix composites. There are ten major tasks in the program which also include evaluation and trade-off studies by Boeing and Douglas aircraft companies.

  1. Inhibitory effects of antioxidant constituents from Melothria heterophylla on matrix metalloproteinase-1 expression in UVA-irradiated human dermal fibroblasts.

    PubMed

    Cho, Y H; Kim, J H; Sim, G S; Lee, B C; Pyo, H B; Park, H D

    2006-01-01

    Matrix metalloproteinases (MMPs) are known to play an important role in photoaging by mediating the degradation of extracellular matrix proteins. To develop a new anti-aging agent for cosmetics from natural products, Melothria heterophylla (Lour.) Cogn. was selected for its antioxidant activity and inhibitory effect on expression of MMP-1 in UVA-irradiated human skin fibroblasts. Two compounds (compounds 1 and 2 ) were isolated from an ethyl acetate soluble fraction of the ethanolic extracts; they were identified as 1,2,4,6-tetra-O-galloyl-beta-(D)-glucopyranose (1) and 3,4,5-trihydroxybenzoic acid (2). These compounds were found to scavenge radicals and reactive oxygen species (ROS) and were measured to have SC50 values of 3.9 microM and 13.3 microM against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and values of 4.3 microM and 4.0 microM against superoxide radicals in the xanthine/xanthine oxidase system, respectively. Compounds 1 and 2 showed a dose-dependent inhibitory effect on the expression and activity of MMP-1 in UVA-induced human skin fibroblasts, but no inhibition of MMP-1 mRNA expression. Therefore, we concluded that compounds 1 and 2 significantly inhibited MMP-1 expression at the protein level. Also, these compounds were determined to have a potent antioxidant activity. From these results, we suggest that these compounds might be useful as a new anti-aging agent for photodamaged skin, but the in vitro findings must be verified in in vivo studies.

  2. Heber D. Curtis: The Re-entry Graduate Student at UVa Who Became an Outstanding Dynamical Astronomer

    NASA Astrophysics Data System (ADS)

    Osterbrock, D. E.

    1998-09-01

    Heber D. Curtis, the great pioneer of nebular and galactic research, later observatory director at Allegheny and then at the University of Michigan, was a dynamical astronomer in the earliest days of photographic radial-velocity measurements. He did his undergraduate work in classical languages at Michigan, where as a student he showed no apparent interest in astronomy. Curtis's first jobs were teaching Latin and Greek at Napa College, then at the College of the Pacific. Both had small Clark refractors and he began observing, then measuring, visual double stars. He decided to become an astronomer, and spent the summers of 1897 and 1898 as a special student at Lick Observatory, and of 1899 at Ann Arbor. In 1900, at the age of 28, married and with two small children, Curtis entered the University of Virginia as a full-time graduate student. Both Yerkes and Lick Observatories had declined to accept him. At Charlottesville Curtis did his Ph.D. thesis on the orbit of Comet 1898 I, received his degree in 1902, and immediately joined the Lick staff. His work on spectroscopic binaries and high-velocity stars at Mount Hamilton and at the Lick Southern Hemisphere Observatory, will be described in this paper. W. W. Campbell and Curtis published the First Catalogue of Spectroscopic Binaries in 1905; it listed all 140 of these objects then known. In 1909, Curtis was recalled to Lick to take over the Crossley reflector and thus left the field of dynamical astronomy. At Santiago, his assistant was George F. Paddock, a UVa M.A. in astronomy who based his Ph.D. thesis on Chile observational data. When Ormond Stone, UVa professor of astronomy and Leander McCormick Observatory director, retired in 1912, Curtis was the first choice to succeed him, but declined the post to remain at Lick.

  3. Near ultraviolet radiation (UVA and UVB) causes a formamidopyrimidine glycosylase-dependent increase in G to T transversions.

    PubMed

    Palmer, C M; Serafini, D M; Schellhorn, H E

    1997-03-01

    In contrast to far-UV (< 290 nm) DNA damage, a large fraction of the DNA damage caused by near-UV is oxygen-dependent, suggesting the involvement of reactive oxygen species (ROS). The oxidized base 8-oxo-7,8-dihydroguanine (GO) is characteristic of ROS-induced DNA damage and is removed by Fapy (formamidopyrimidine) glycosylase. We have recently shown that Escherichia coli strains deficient in Fapy glycosylase (fpg) are hypersensitive to the lethal effects of UVA but not far-UV (UVC), suggesting lesions recognized by this enzyme may be important premutagenic or lethal lesions generated by near-UV radiation. In this study, we have found that while the far-UV-induced mutation rates of Fapy-deficient and wild-type strains were similar, near-UV (UVA and UVB) was hypermutagenic to a Fapy-deficient strain, causing a dose-dependent increase in induced mutation relative to wild type (up to five-fold at 200 kJ/m2). Using a plasmid back mutation assay, the predominant near-UV-induced mutations in both wild-type and Fapy-deficient strains were found to be C-->T transitions and G -->T transversions. The former is probably due to replicative bypass of pyrimidine dimers or (6-4) photoproducts that are known to be generated by near-UV, whereas the latter may be due to mispairing of GO lesions with adenine during replication. Consistent with this, the frequency of near-UV-induced G-->T transversions was 16-fold higher in a Fapy-deficient strain than a wild-type strain.

  4. Solar disinfection of drinking water (SODIS): an investigation of the effect of UV-A dose on inactivation efficiency.

    PubMed

    Ubomba-Jaswa, Eunice; Navntoft, Christian; Polo-López, M Inmaculada; Fernandez-Ibáñez, Pilar; McGuigan, Kevin G

    2009-05-01

    The effect of solar UV-A irradiance and solar UV-A dose on the inactivation of Escherichia coli K-12 using solar disinfection (SODIS) was studied. E. coli K-12 was seeded in natural well-water contained in borosilicate glass tubes and exposed to sunlight at different irradiances and doses of solar UV radiation. In addition, E. coli K-12 was also inoculated into poly(ethylene) terephthalate (PET) bottles and in a continuous flow system (10 L min(-1)) to determine the effect of an interrupted and uninterrupted solar dose on inactivation. Results showed that inactivation from approximately 10(6) CFU mL(-1) to below the detection level (4 CFU/mL) for E. coli K-12, is a function of the total uninterrupted dose delivered to the bacteria and that the minimum dose should be >108 kJ m(-2) for the conditions described (spectral range of 0.295-0.385 microm). For complete inactivation to below the limit of detection, this dose needs to be received regardless of the incident solar UV intensity and needs to be delivered in a continuous and uninterrupted manner. This is illustrated by a continuous flow system in which bacteria were not fully inactivated (residual viable concentration approximately 10(2) CFU/mL) even after 5 h of exposure to strong sunlight and a cumulative dose of >108 kJ m(-2). This has serious implications for attempts to scale-up solar disinfection through the use of re-circulatory continuous flow reactors.

  5. Row orientation effect on UV-B, UV-A and PAR solar irradiation components in vineyards at Tuscany, Italy

    NASA Astrophysics Data System (ADS)

    Grifoni, D.; Carreras, G.; Zipoli, G.; Sabatini, F.; Dalla Marta, A.; Orlandini, S.

    2008-11-01

    Besides playing an essential role in plant photosynthesis, solar radiation is also involved in many other important biological processes. In particular, it has been demonstrated that ultraviolet (UV) solar radiation plays a relevant role in grapevines ( Vitis vinifera) in the production of certain important chemical compounds directly responsible for yield and wine quality. Moreover, the exposure to UV-B radiation (280-320 nm) can affect plant-disease interaction by influencing the behaviour of both pathogen and host. The main objective of this research was to characterise the solar radiative regime of a vineyard, in terms of photosynthetically active radiation (PAR) and UV components. In this analysis, solar spectral UV irradiance components, broadband UV (280-400 nm), spectral UV-B and UV-A (320-400 nm), the biological effective UVBE, as well as the PAR (400-700 nm) component, were all considered. The diurnal patterns of these quantities and the UV-B/PAR and UV-B/UV-A ratios were analysed to investigate the effect of row orientation of the vineyard in combination with solar azimuth and elevation angles. The distribution of PAR and UV irradiance at various heights of the vertical sides of the rows was also studied. The results showed that the highest portion of plants received higher levels of daily radiation, especially the UV-B component. Row orientation of the vines had a pronounced effect on the global PAR received by the two sides of the rows and, to a lesser extent, UV-A and UV-B. When only the diffused component was considered, this geometrical effect was greatly attenuated. UV-B/PAR and UV-A/PAR ratios were also affected, with potential consequences on physiological processes. Because of the high diffusive capacity of the UV-B radiation, the UV-B/PAR ratio was significantly lower on the plant portions exposed to full sunlight than on those in the shade.

  6. A Questao da Moral na Cultura Contemporanea (The Moral Question in Contemporary Culture).

    ERIC Educational Resources Information Center

    Barcellos, Carine

    2000-01-01

    Extends the debate concerning the discussion about the possibility of ethics on the present configuration of a social ethos based on the reflection of the circumscription of morality within contemporary culture. Turns to the internal debate in psychology, for clarification. (BT)

  7. Topical AC-11 abates actinic keratoses and early squamous cell cancers in hairless mice exposed to Ultraviolet A (UVA) radiation.

    PubMed

    Mentor, Julian M; Etemadi, Amir; Patta, Abrienne M; Scheinfeld, Noah

    2015-04-16

    AC-11 is an aqueous extract of the botanical, Uncaria tomentosa, which has a variety of effects that enhance DNA repair and down regulate inflammation. AC-11 is essentially free of oxindole alkaloids (< 0.05%, w/w) but contains more than 8% carboxy alkyl esters (CAEs) as their active ingredients. Three groups of 10 outbred SK-1 hairless or SK-II hairless strains of mice each were treated with AC-11 at 0.5%, 1.5%, and 3.0% in a non-irritating, dye-free, perfume-free, and fragrance-free vanishing cream vehicle. Ten mice used vehicle only and 10 were untreated. Each concentration of AC-11 and was applied daily to the backs of the mice prior to exposure to a 1,600-watt solar simulator used in this work (Solar Light Co. Philadelphia, PA) emitting (mainly Ultraviolet A (UVA) and B (UVB) radiation) duration of the experimental period with UVB wavelengths was filtered out with a 1.0 cm Schott WG 345 filter. AC-11 with a peak absorption at 200nm does act as a sun block. We tested for and focused on clinical appearance of mice and histological appearance of tumors in mice rather than metrics of radiation generated inflammation. Tumor progression scores were assigned as follows: 4+ = extensive tumor development; 3+ = early malignancies (raised palpable plaques)(early squamous cell cancers) 2+ = firm scaling, palpable keratosis (actinic keratoses); 1+ = light scaling with erythema. Following a total cumulative dose of 738 J/cm2, 85.7% all of the irradiated control animals, which did not receive AC-11 had precancerous actinic keratosis (AK)-type lesions (2+) (64.3% versus 42.9%) or early squamous cell carcinoma (SCC) (3+) (21.4% vs. 4.8%), in comparison with 47.7 % of AC-11-treated animals. There were no significant differences between the AC-11 groups. Three months after cessation of exposure to UVA radiation, the lesions in all but three of the 14 animals which were treated with AC-11 that were still evaluable irradiated with UVA radiation progressed to papillomas and frank

  8. Solar radiation (PAR and UVA) and water temperature in relation to biochemical performance of Gelidium corneum (Gelidiales, Rhodophyta) in subtidal bottoms off the Basque coast

    NASA Astrophysics Data System (ADS)

    Quintano, Endika; Ganzedo, Unai; Díez, Isabel; Figueroa, Félix L.; Gorostiaga, José M.

    2013-10-01

    Gelidium corneum (Hudson) J.V. Lamouroux is a very important primary producer in the Cantabrian coastal ecosystem. Some local declines in their populations have been recently detected in the Basque coast. Occurrences of yellowing and an unusual branch breakdown pattern have also been reported for some G. corneum populations. In order to gain further insight into those environmental stressors operating at a local scale, here we investigate if shallow subtidal populations of G. corneum living under potentially different conditions of irradiance (PAR and UVA) and water temperature exhibit differences in some biochemical indicators of stress, namely C:N, antioxidant activity (radical cation of 2,2‧-azino-bis (3-ethylbenzothiazoline-6-sulfonate); ABTS+ assay) and mycosporine-like amino acids (MAAs) (Asterine 330 and Palythine). We hypothesised that G. corneum subjected to higher ambient levels of irradiance and water temperature would show higher C:N ratios, lower antioxidant activity and higher MAA concentrations. Our results partially support this hypothesis. We found that G. corneum exposed to increased levels of irradiance (PAR, UVA) exhibited greater C:N ratios and lower antioxidant activity (higher IC50), whereas no relationship was found regarding MAAs. No differences in biochemical performance in relation to temperature were detected among G. corneum exposed to comparable high light. Similarly, G. corneum growing under lower UVA radiation levels showed no differences in any of the measured biochemical variables with regard to PAR and water temperature. These findings suggest that, among the environmental factors examined, UVA radiation may be an important driver in regulating the along-shore variation in G. corneum biochemical performance. Therefore, the role of irradiance, especially UV radiation, in potential future alterations in Cantabrian G. corneum populations cannot be ruled out as a potential underlying factor.

  9. UVA photoirradiation of benzo[a]pyrene metabolites: induction of cytotoxicity, reactive oxygen species, and lipid peroxidation.

    PubMed

    Xia, Qingsu; Chiang, Hsiu-Mei; Yin, Jun-Jie; Chen, Shoujun; Cai, Lining; Yu, Hongtao; Fu, Peter P

    2015-10-01

    Benzo[a]pyrene (BaP) is a prototype for studying carcinogenesis of polycyclic aromatic hydrocarbons (PAHs). We have long been interested in studying the phototoxicity of PAHs. In this study, we determined that metabolism of BaP by human skin HaCaT keratinocytes resulted in six identified phase I metabolites, for example, BaP trans-7,8-dihydrodiol (BaP t-7,8-diol), BaP t-4,5-diol, BaP t-9,10-diol, 3-hydroxybenzo[a]pyrene (3-OH-BaP), BaP (7,10/8,9)tetrol, and BaP (7/8,9,10)tetrol. The photocytotoxicity of BaP, 3-OH-BaP, BaP t-7,8-diol, BaP trans-7,8-diol-anti-9,10-epoxide (BPDE), and BaP (7,10/8,9)tetrol in the HaCaT keratinocytes was examined. When irradiated with 1.0 J/cm(2) UVA light, these compounds when tested at doses of 0.1, 0.2, and 0.5 μM, all induced photocytotoxicity in a dose-dependent manner. When photoirradiation was conducted in the presence of a lipid (methyl linoleate), BaP metabolites, BPDE, and three related PAHs, pyrene, 7,8,9,10-tetrahydro-BaP trans-7,8-diol, and 7,8,9,10-tetrahydro-BaP trans-9,10-diol, all induced lipid peroxidation. The formation of lipid peroxides by BaP t-7,8-diol was inhibited by NaN3 and enhanced by deuterated methanol, which suggests that singlet oxygen may be involved in the generation of lipid peroxides. The formation of lipid hydroperoxides was partially inhibited by superoxide dismutase (SOD). Electron spin resonance spin trapping experiments indicated that both singlet oxygen and superoxide radical anion were generated from UVA photoirradiation of BPDE in a light dose responding manner.

  10. Low cost UVA-LED as a radiation source for the photo-Fenton process: a new approach for micropollutant removal from urban wastewater.

    PubMed

    de la Obra, I; Esteban García, B; García Sánchez, J L; Casas López, J L; Sánchez Pérez, J A

    2017-01-18

    Light Emitting Diode (LED) technology has matured sufficiently to be considered as an alternative UVA radiation source in photoreactors. Currently, low energy consuming LEDs with a wide range of wavelengths and radiant flux are readily available. In this study, UVA-LEDs were used as a radiation source for the photo-Fenton process as tertiary treatment. The water matrix used was a simulated secondary effluent doped with 200 μg L(-1) of the pesticide acetamiprid (ACTM) due to its recalcitrant nature. All experiments were carried out in a LED-box reactor at pH 2.8. The main purpose of this research was to gain some insight into the relationships among energy supply, LED consumption, UVA irradiance and reaction rate. The effect of LED wavelength on energy efficiency for ACTM degradation was studied by varying the iron concentration and liquid depth. Three wavelengths (365, 385 and 400 nm) and two iron concentrations (5 and 11 mg L(-1)) for two different liquid depths (5 and 15 cm) were evaluated in order to obtain more energy efficient conditions. The results suggest that while the wavelength of 365 nm with 11 mg Fe(2+) L(-1) was the best condition for ACTM degradation, the wavelength of 385 nm had slower kinetics, but higher energy efficiency.

  11. Penetration of UV-A, UV-B, blue, and red light into leaf tissues of pecan measured by a fiber optic microprobe system

    NASA Astrophysics Data System (ADS)

    Qi, Yadong; Bai, Shuju; Vogelmann, Thomas C.; Heisler, Gordon M.

    2003-11-01

    The depth of light penetration from the adaxial surfaces of the mature leaves of pecan (Carya illinoensis) was measured using a fiber optic microprobe system at four wavelengths: UV-B (310nm), UV-A (360 nm), blue light (430nm), and red light (680nm). The average thickness of the leaf adaxial epidermal layer was 15um and the total leaf thickness was 219um. The patterns of the light attenuation by the leaf tissues exhibited strong wavelength dependence. The leaf adaxial epidermal layer was chiefly responsible for absorbing the UV-A UV-B radiation. About 98% of 310 nm light was steeply attenuated within the first 5 um of the adaxial epidermis; thus, very little UV-B radiation was transmitted to the mesophyll tissues where contain photosynthetically sensitive sites. The adaxial epidermis also attenuated 96% of the UV-A radiation. In contrast, the blue and red light penetrated much deeper and was gradually attenutated by the leaves. The mesophyll tissues attenuated 17% of the blue light and 42% of the red light, which were available for photosynthesis use. Since the epidermal layer absorbed nearly all UV-B light, it acted as an effective filter screening out the harmful radiation and protecting photosynthetically sensitive tissues from the UV-B damage. Therefore, the epidermal function of the UV-B screening effectiveness can be regarded as one of the UV-B protection mechanisms in pecan.

  12. Solar ultraviolet radiation induces biological alterations in human skin in vitro: relevance of a well-balanced UVA/UVB protection.

    PubMed

    Bernerd, Francoise; Marionnet, Claire; Duval, Christine

    2012-06-01

    Cutaneous damages such as sunburn, pigmentation, and photoaging are known to be induced by acute as well as repetitive sun exposure. Not only for basic research, but also for the design of the most efficient photoprotection, it is crucial to understand and identify the early biological events occurring after ultraviolet (UV) exposure. Reconstructed human skin models provide excellent and reliable in vitro tools to study the UV-induced alterations of the different skin cell types, keratinocytes, fibroblasts, and melanocytes in a dose- and time-dependent manner. Using different in vitro human skin models, the effects of UV light (UVB and UVA) were investigated. UVB-induced damages are essentially epidermal, with the typical sunburn cells and DNA lesions, whereas UVA radiation-induced damages are mostly located within the dermal compartment. Pigmentation can also be obtained after solar simulated radiation exposure of pigmented reconstructed skin model. Those models are also highly adequate to assess the potential of sunscreens to protect the skin from UV-associated damage, sunburn reaction, photoaging, and pigmentation. The results showed that an effective photoprotection is provided by broad-spectrum sunscreens with a potent absorption in both UVB and UVA ranges.

  13. Structure activity relationship of antioxidative property of flavonoids and inhibitory effect on matrix metalloproteinase activity in UVA-irradiated human dermal fibroblast.

    PubMed

    Sim, Gwan-Sub; Lee, Bum-Chun; Cho, Ho Seung; Lee, Jae Woong; Kim, Jin-Hwa; Lee, Dong-Hwan; Kim, Jin-Hui; Pyo, Hyeong-Bae; Moon, Dong Cheul; Oh, Ki-Wan; Yun, Yeo Pyo; Hong, Jin Tae

    2007-03-01

    Collagenase, a matrix metalloproteinases (MMPs), is a key regulator in the photoaging process of skin due to the reactive oxygen species generated after exposure to ultraviolet A (UVA). Flavonoid compounds have been demonstrated to possess antioxidant properties, and could be useful in the prevention of photoaging. In this study, to investigate the structure-activity relationship of flavonoid compounds on their antioxidant property and inhibitory effects against the MMP activity, the effects of several flavonoids; myricetin, quercetin, kaempferol, luteolin, apigenin and chrysin, on the reactive oxygen species scavengering activity and inhibitory effect against the MMP activity were examined in vitro and in human dermal fibroblasts induced by UVA. The relative order of antioxidative efficacy, as determined using the 1, 1-diphenyl-2-picrylhydrazyl (DPPH) method and the xanthine/xanthine oxidase system, was as follows; flavones: luteolin > apigenin > chrysin, flavonols: myricetin > quercetin > kaempferol, and correlated with the respective number of OH group on their B-ring. In good correlation with the antioxidant properties, the flavonoids inhibited the collagenase activities, in a dose-dependent manner, and the MMP expression. These results suggested the UVA induced antioxidative activity and inhibitory effects of flavonoids on the collagenase in human dermal fibroblasts depends on the number of OH group in the flavonoid structure, and those with a higher number of OH group may be more useful in the prevention of UV stressed skin aging.

  14. Identification of influential events concerning the Antarctic ozone hole over southern Brazil and the biological effects induced by UVB and UVA radiation in an endemic treefrog species.

    PubMed

    Passaglia Schuch, André; Dos Santos, Mauricio Beux; Mendes Lipinski, Victor; Vaz Peres, Lucas; Dos Santos, Caroline Peripolli; Zanini Cechin, Sonia; Jorge Schuch, Nelson; Kirsh Pinheiro, Damaris; da Silva Loreto, Elgion Lúcio

    2015-08-01

    The increased incidence of solar ultraviolet radiation (UV) due to ozone depletion has been affecting both terrestrial and aquatic ecosystems and it may help to explain the enigmatic decline of amphibian populations in specific localities. In this work, influential events concerning the Antarctic ozone hole were identified in a dataset containing 35 years of ozone measurements over southern Brazil. The effects of environmental doses of UVB and UVA radiation were addressed on the morphology and development of Hypsiboas pulchellus tadpole (Anura: Hylidae), as well as on the induction of malformation after the conclusion of metamorphosis. These analyzes were complemented by the detection of micronucleus formation in blood cells. 72 ozone depletion events were identified from 1979 to 2013. Surprisingly, their yearly frequency increased three-fold during the last 17 years. The results clearly show that H. pulchellus tadpole are much more sensitive to UVB than UVA light, which reduces their survival and developmental rates. Additionally, the rates of micronucleus formation by UVB were considerably higher compared to UVA even after the activation of photolyases enzymes by a further photoreactivation treatment. Consequently, a higher occurrence of malformation was observed in UVB-irradiated individuals. These results demonstrate the severe genotoxic impact of UVB radiation on this treefrog species and its importance for further studies aimed to assess the impact of the increased levels of solar UVB radiation on declining species of the Hylidae family.

  15. On the accuracy of the independent column approximation in calculating the downward fluxes in the UVA, UVB, and PAR spectral ranges

    NASA Astrophysics Data System (ADS)

    Scheirer, Ronald; Macke, Andreas

    2001-07-01

    In order to investigate the accuracy of simplification in modeling the radiative transfer in those solar spectral regions with major impacts on bio-organisms, i.e., the UVA (0.32-0.4 μm), the UVB (0.28-0.32 μm), and the photosynthetically active radiation (PAR, 0.4-0.7 μm), radiative transfer calculations with varying treatments of cloud geometries (plane-parallel homogeneous (PPHOM), independent column approximation (ICA), and three-dimensional (3-D) inhomogeneous) have been performed. The complete sets of atmospheric information for 133 cloud realizations are taken from the three-dimensional nonhydrostatic mesoscale atmospheric model (GESIMA). A Monte Carlo radiative transfer model (GRIMALDI) has been developed that simulates scattering and absorption for arbitrarily three-dimensional distributions of cloud hydrometeors, air molecules, and water vapor. Results are shown for domain-averaged direct and total transmission (and so, implicitly, diffuse transmission) at the ground surface. In the UVA the PPHOM assumption leads to an underestimation in direct (total) downward flux by as much as 43 (28) W m-2, which is about 49% (32%) of the incoming irradiation, whereas results based on the ICA are almost identical to the 3-D case, except for convective clouds where the error in the UVA for direct (total) downward flux reaches 5 (2) W m-2, or 6% (2%) of the incoming solar irradiation.

  16. Effect of Ultraviolet-A (UV-A) and Ultraviolet-C (UV-C) Light on Mechanical Properties of Oyster Mushrooms during Growth

    PubMed Central

    Edward, Tindibale L.; Kirui, M. S. K.; Omolo, Josiah O.; Ngumbu, Richard G.; Odhiambo, Peter M.

    2014-01-01

    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. PMID:25580117

  17. Comparing the effects of mitochondrial targeted and localized antioxidants with cellular antioxidants in human skin cells exposed to UVA and hydrogen peroxide.

    PubMed

    Oyewole, Anne O; Wilmot, Marie-Claire; Fowler, Mark; Birch-Machin, Mark A

    2014-01-01

    Skin cancer and aging are linked to increased cellular reactive oxygen species (ROS), particularly following exposure to ultraviolet A (UVA) in sunlight. As mitochondria are the main source of cellular ROS, this study compared the protective effects of mitochondria-targeted and -localized antioxidants (MitoQ and tiron, respectively) with cellular antioxidants against oxidative stress-induced [UVA and hydrogen peroxide (H2O2)] mitochondrial DNA (mtDNA) damage in human dermal fibroblasts. With the use of a long quantitative PCR assay, tiron (EC50 10 mM) was found to confer complete (100%) protection (P<0.001) against both UVA- and H2O2-induced mtDNA damage, whereas MitoQ (EC50 750 nM) provided less protection (17 and 32%, respectively; P<0.05). This particular protective effect of tiron was greater than a range of cellular antioxidants investigated. The nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway provides cellular protection against oxidative stress. An ELISA assay for the Nrf2 target gene heme oxygenase-1 (HO-1) and studies using Nrf2 small interfering RNA both indicated that tiron's mode of action was Nrf2 independent. The comet assay showed that tiron's protective effect against H2O2-induced nuclear DNA damage was greater than the cellular antioxidants and MitoQ (P<0.001). This study provides a platform to investigate molecules with similar structure to tiron as potent and clinically relevant antioxidants.

  18. In vitro erythemal UV-A protection factors of inorganic sunscreens distributed in aqueous media using carnauba wax-decyl oleate nanoparticles.

    PubMed

    Villalobos-Hernández, J R; Müller-Goymann, C C

    2007-01-01

    This paper describes the in vitro photoprotection in the UV-A range, i.e. 320-400 nm obtained by the use of carnauba wax-decyl oleate nanoparticles either as encapsulation systems or as accompanying vehicles for inorganic sunscreens such as barium sulfate, strontium carbonate and titanium dioxide. Lipid-free inorganic sunscreen nanosuspensions, inorganic sunscreen-free wax-oil nanoparticle suspensions and wax-oil nanoparticle suspensions containing inorganic sunscreens dispersed either in their oil phase or their aqueous phase were prepared by high pressure homogenization. The in vitro erythemal UV-A protection factors (EUV-A PFs) of the nanosuspensions were calculated by means of a sun protection analyzer. EUV-A PFs being no higher than 4 were obtained by the encapsulation of barium sulfate and strontium carbonate, meanwhile by the distribution of titanium dioxide in presence of wax-oil nanoparticles, the EUV-A PFs varied between 2 and 19. The increase in the EUV-A PFs of the titanium dioxide obtained by the use of wax-oil nanoparticles demonstrated a better performance of the sun protection properties of this pigment in the UV-A region.

  19. Photocatalytic degradation and mineralization of microcystin-LR under UV-A, solar and visible light using nanostructured nitrogen doped TiO2.

    PubMed

    Triantis, T M; Fotiou, T; Kaloudis, T; Kontos, A G; Falaras, P; Dionysiou, D D; Pelaez, M; Hiskia, A

    2012-04-15

    In an attempt to face serious environmental hazards, the degradation of microcystin-LR (MC-LR), one of the most common and more toxic water soluble cyanotoxin compounds released by cyanobacteria blooms, was investigated using nitrogen doped TiO(2) (N-TiO(2)) photocatalyst, under UV-A, solar and visible light. Commercial Degussa P25 TiO(2), Kronos and reference TiO(2) nanopowders were used for comparison. It was found that under UV-A irradiation, all photocatalysts were effective in toxin elimination. The higher MC-LR degradation (99%) was observed with Degussa P25 TiO(2) followed by N-TiO(2) with 96% toxin destruction after 20 min of illumination. Under solar light illumination, N-TiO(2) nanocatalyst exhibits similar photocatalytic activity with that of commercially available materials such as Degussa P25 and Kronos TiO(2) for the destruction of MC-LR. Upon irradiation with visible light Degussa P25 practically did not show any response, while the N-TiO(2) displayed remarkable photocatalytic efficiency. In addition, it has been shown that photodegradation products did not present any significant protein phosphatase inhibition activity, proving that toxicity is proportional only to the remaining MC-LR in solution. Finally, total organic carbon (TOC) and inorganic ions (NO(2)(-), NO(3)(-) and NH(4)(+)) determinations confirmed that complete photocatalytic mineralization of MC-LR was achieved under both UV-A and solar light.

  20. Photocatalytic degradation of cylindrospermopsin under UV-A, solar and visible light using TiO2. Mineralization and intermediate products.

    PubMed

    Fotiou, Theodora; Triantis, Theodoros; Kaloudis, Triantafyllos; Hiskia, Anastasia

    2015-01-01

    Cyanobacteria (blue-green algae) are considered an important water quality problem, since several genera can produce toxins, called cyanotoxins that are harmful to human health. Cylindrospermopsin (CYN) is an alkaloid-like potent cyanotoxin that has been reported in water reservoirs and lakes worldwide. In this paper the removal of CYN from water by UV-A, solar and visible light photocatalysis was investigated. Two different commercially available TiO2 photocatalysts were used, i.e., Degussa P25 and Kronos-vlp7000. Complete degradation of CYN was achieved with both photocatalysts in 15 and 40 min under UV-A and 40 and 120 min under solar light irradiation, for Degussa P25 and Kronos vlp-7000 respectively. Experiments in the absence of photocatalysts showed that direct photolysis was negligible. Under visible light irradiation only the Kronos vlp-7000 which is a visible light activated catalyst was able to degrade CYN. A number of intermediates were identified and a complete degradation pathway is proposed, leading to the conclusion that hydroxyl radical attack is the main mechanism followed. TOC and inorganic ions (NO2-, NO3-, SO4(2-) and NH4+) determinations suggested that complete mineralization of CYN was achieved under UV-A in the presence of Degussa P25.

  1. Hydrogen-rich water reestablishes ROS homeostasis but exerts differential effects on anthocyanin synthesis in two varieties of radish sprouts under UV-A irradiation.

    PubMed

    Su, Nana; Wu, Qi; Liu, Yuanyuan; Cai, Jiangtao; Shen, Wenbiao; Xia, Kai; Cui, Jin

    2014-07-09

    The aims of the study were to investigate whether hydrogen gas (H2) was involved in regulation of anthocyanin biosynthesis in two contrasting radish (Raphanus sativus L.) varieties (low [LA] and high [HA] level of anthocyanin) under UV irradiation. The results showed that hydrogen-rich water (HRW) significantly blocked the UV-A-induced increase of H2O2 and O2(•-) accumulation, and enhanced the UV-A-induced increase of superoxide dismutase (SOD) and ascorbate peroxidase (APX) activities in LA and HA. Furthermore, UV-A-induced increase of anthocyanin and total phenols was further enhanced only in HA sprouts cotreated with HRW. LC-MS/MS analysis showed that five anthocyanidins existed in HA sprouts, but only two in LA sprouts. Meanwhile, the cyanidin was the most abundant anthocyanidin in HA, and the cyanidin was 2-fold higher cotreated with HRW than UV-A. Molecular analyses showed that the anthocyanin biosynthesis-related genes were upregulated significantly in both HA (in particular) and LA sprouts treated with HRW plus UV-A. These data imply that HRW reestablishes reactive oxygen species homeostasis in both LA and HA, but exerts different effects on anthocyanin accumulation between them under UV-A.

  2. Coilin is rapidly recruited to UVA-induced DNA lesions and γ-radiation affects localized movement of Cajal bodies.

    PubMed

    Bártová, Eva; Foltánková, Veronika; Legartová, Soňa; Sehnalová, Petra; Sorokin, Dmitry V; Suchánková, Jana; Kozubek, Stanislav

    2014-01-01

    Cajal bodies are important nuclear structures containing proteins that preferentially regulate RNA-related metabolism. We investigated the cell-type specific nuclear distribution of Cajal bodies and the level of coilin, a protein of Cajal bodies, in non-irradiated and irradiated human tumor cell lines and embryonic stem (ES) cells. Cajal bodies were localized in different nuclear compartments, including DAPI-poor regions, in the proximity of chromocenters, and adjacent to nucleoli. The number of Cajal bodies per nucleus was cell cycle-dependent, with higher numbers occurring during G2 phase. Human ES cells contained a high coilin level in the nucleoplasm, but coilin-positive Cajal bodies were also identified in nuclei of mouse and human ES cells. Coilin, but not SMN, recognized UVA-induced DNA lesions, which was cell cycle-independent. Treatment with γ-radiation reduced the localized movement of Cajal bodies in many cell types and GFP-coilin fluorescence recovery after photobleaching was very fast in nucleoplasm in comparison with GFP-coilin recovery in DNA lesions. By contrast, nucleolus-localized coilin displayed very slow fluorescence recovery after photobleaching, which indicates very slow rates of protein diffusion, especially in nucleoli of mouse ES cells.

  3. Influence of flavonoids and vitamins on the MMP- and TIMP-expression of human dermal fibroblasts after UVA irradiation.

    PubMed

    Hantke, Bernd; Lahmann, Christine; Venzke, Kirsten; Fischer, Tim; Kocourek, Andreas; Windsor, L Jack; Bergemann, Jörg; Stäb, Franz; Tschesche, Harald

    2002-10-01

    UV irradiation leads to distinct changes in skin connective tissue by degradation of collagen, for example. Many of these alterations in the extracellular matrix are mediated by MMPs (matrix metalloproteinases) with reduced content of their antagonist TIMPs (tissue inhibitors of metalloproteinases). Potential candidates to reduce MMP activity in the skin after solar stimulation were examined. The influence of vitamin C, vitamin E and the flavonoids AGR (alpha-glucosylrutin) and 8-prenylnaringenine on the MMP and TIMP expression was investigated. Human dermal fibroblasts were incubated with these additives and irradiated with UVA [10 J cm(-2)]. The gene expression of MMP-1 (collagenase-1) and TIMP-1, the protein expression of MMP-1, MMP-2 (gelatinase-A), TIMP-1 and TIMP-2 as well as the enzyme activity of MMP-1 and MMP-2 were examined. AGR and vitamins C and E were shown to reduce MMP expression and activity, whereas 8-prenylnaringenine appeared to be responsible for the opposite effect. None of the substances considerably influenced the TIMP levels. AGR represented the most effective additive in reducing the collagenase protein expression to 60% and may be useful to level out the MMP activity in the skin after sun exposure. Furthermore, no protein expression of MMP-8, MMP-9, MMP-12 and MMP-13 could be detected.

  4. Visible light and/or UVA offer a strong amplification of the anti-tumor effect of curcumin.

    PubMed

    Bernd, August

    2014-01-01

    Curcumin, a dietary pigment from the plant Curcuma longa, inhibits cell proliferation and induces apoptosis in different cell lines. The therapeutic benefit is hampered by a very low absorption after trans-dermal or oral application. Therefore, great efforts were undertaken to enhance the effectiveness of curcumin. Recently, it was demonstrated that curcumin offers the described effects also at low concentrations (0.2-1 μg/ml) when applied in combination with UVA or visible light. The efficacy of this combination was shown in human epidermal keratinocytes and in a panel of other cell species in vitro as well as in a xenograft tumor model with A431 tumor cells injected subcutaneously in the flanks of NMRI nude mice in vivo. The treatment of keratinocytes with curcumin and light resulted in the inhibition of cell growth, and in the induction of apoptosis, whereas no toxic cell membrane damage was detectable. The treatment of tumor bearing nude mice with curcumin and visible light resulted in reduced tumor volumes, reduced proliferation rates, and the induction of apoptosis in the tumors. On the molecular level inhibition of extracellular regulated kinases 1/2 and epidermal growth factor receptor was observed which may aid to inhibition of proliferation and induction of apoptosis. This review covers the experiences of the new combination treatment of human tumors.

  5. Triplet-triplet energy transfer from a UV-A absorber butylmethoxydibenzoylmethane to UV-B absorbers.

    PubMed

    Kikuchi, Azusa; Oguchi-Fujiyama, Nozomi; Miyazawa, Kazuyuki; Yagi, Mikio

    2014-01-01

    The phosphorescence decay of a UV-A absorber, 4-tert-butyl-4'-methoxydibenzolymethane (BMDBM) has been observed following a 355 nm laser excitation in the absence and presence of UV-B absorbers, 2-ethylhexyl 4-methoxycinnamate (octyl methoxycinnamate, OMC) and octocrylene (OCR) in ethanol at 77 K. The lifetime of the lowest excited triplet (T1) state of BMDBM is significantly reduced in the presence of OMC and OCR. The observed quenching of BMDBM triplet by OMC and OCR suggests that the intermolecular triplet-triplet energy transfer occurs from BMDBM to OMC and OCR. The T1 state of OCR is nonphosphorescent or very weakly phosphorescent. However, we have shown that the energy level of the T1 state of OCR is lower than that of the enol form of BMDBM. Our methodology of energy-donor phosphorescence decay measurements can be applied to the study of the triplet-triplet energy transfer between UV absorbers even if the energy acceptor is nonphosphorescent. In addition, the delayed fluorescence of BMDBM due to triplet-triplet annihilation was observed in the BMDBM-OMC and BMDBM-OCR mixtures in ethanol at 77 K. Delayed fluorescence is one of the deactivation processes of the excited states of BMDBM under our experimental conditions.

  6. Low-dose psoralen and UVA (PUVA) therapy-enhanced arterial shrinkage after balloon angioplasty in rabbits

    NASA Astrophysics Data System (ADS)

    Perree, Jop; van Leeuwen, Ton G. J. M.; Velema, Evelyn; Borst, Cornelius

    1998-07-01

    Restenosis after balloon angioplasty is caused by both intimal hyperplasia and arterial shrinkage (constrictive remodeling). Previous studies have indicated the inhibitory effect of photodynamic therapy on intimal hyperplasia development after angioplasty. The potential of a photoactivation regime (Psoralen + UVA irradiation: PUVA), which does not cause unwanted systemic side effects, for the prevention of both intimal hyperplasia formation and constrictive remodeling following balloon dilation was explored in the present study. In the rabbit iliac artery, balloon dilation followed by PUVA- therapy at a radiant exposure of 1 J/cm2 was performed (n equals 10). Control balloon dilation was performed in the contralateral arteries (n equals 10). After 4 weeks of survival, angiographic lumen renarrowing was determined in terms of intimal hyperplasia and constrictive remodeling. Late loss, but not intimal hyperplasia, was significantly larger in the PUVA group as compared to the control group (p less than 0.05). This difference in angiographic lumen loss can only be attributed to the difference in constrictive remodeling (arterial shrinkage). Thus, PUVA-therapy did not prevent intimal hyperplasia following balloon dilation. PUVA-therapy even enhanced luminal narrowing by augmented constrictive arterial remodeling.

  7. UVA Photoirradiation of Nitro-Polycyclic Aromatic Hydrocarbons—Induction of Reactive Oxygen Species and Formation of Lipid Peroxides †

    PubMed Central

    Xia, Qingsu; Yin, Jun J.; Zhao, Yuewei; Wu, Yuh-Sen; Wang, Yu-Qui; Ma, Liang; Chen, Shoujun; Sun, Xin; Fu, Peter P.; Yu, Hongtao

    2013-01-01

    Nitro-polycyclic aromatic hydrocarbons (nitro-PAHs) are a class of genotoxic environmental contaminants. We have long been interested in determining the mechanisms by which nitro-PAHs induce genotoxicity. Although the metabolic activation of nitro-PAHs leading to toxicological activities has been well studied, the photo-induced activation of nitro-PAHs has seldom been reported. In this paper, we report photo-induced lipid peroxidation by 19 nitro-PAHs. The results indicated that all but two of the nitro-PAHs can induce lipid peroxidation. Mechanistic studies suggest that lipid peroxidation by nitro-PAHs is mediated by free radicals generated in the reaction. There was no structural correlation between the nitro-PAHs and their ability to induce lipid peroxidation upon UVA irradiation, or between the HOMO-LUMO gap and the ability to cause lipid peroxidation. Most of the nitro-PAHs are less potent in terms of causing lipid peroxidation than their parent PAHs. The lack of correlation is attributed to the complex photophysics and photochemistry of the nitro-PAHs and the yield of reactive oxygen species (ROS) and other factors. PMID:23493032

  8. Rutin as a Mediator of Lipid Metabolism and Cellular Signaling Pathways Interactions in Fibroblasts Altered by UVA and UVB Radiation

    PubMed Central

    Rybałtowska-Kawałko, Paula

    2017-01-01

    Background. Rutin is a natural nutraceutical that is a promising compound for the prevention of UV-induced metabolic changes in skin cells. The aim of this study was to examine the effects of rutin on redox and endocannabinoid systems, as well as proinflammatory and proapoptotic processes, in UV-irradiated fibroblasts. Methods. Fibroblasts exposed to UVA and UVB radiation were treated with rutin. The activities and levels of oxidants/antioxidants and endocannabinoid system components, as well as lipid, DNA, and protein oxidation products, and the proinflammatory and pro/antiapoptotic proteins expression were measured. Results. Rutin reduced UV-induced proinflammatory response and ROS generation and enhanced the activity/levels of antioxidants (SOD, GSH-Px, vitamin E, GSH, and Trx). Rutin also normalized UV-induced Nrf2 expression. Its biological activity prevented changes in the levels of the lipid mediators: MDA, 4-HNE, and endocannabinoids, as well as the endocannabinoid receptors CB1/2, VR1, and GPR55 expression. Furthermore, rutin prevented the protein modifications (tyrosine derivatives formation in particular) and decreased the levels of the proapoptotic markers—caspase-3 and cytochrome c. Conclusion. Rutin prevents UV-induced inflammation and redox imbalance at protein and transcriptional level which favors lipid, protein, and DNA protection. In consequence rutin regulates endocannabinoid system and apoptotic balance. PMID:28168010

  9. Solar urticaria with a wide action spectrum from UVB to visible light complicated with UVA-induced polymorphous light eruption.

    PubMed

    Kishimoto, Izumi; Uetsu, Naoko; Tanimura, Hirotsugu; Fujii, Hidetaka; Okamoto, Hiroyuki

    2017-02-04

    Solar urticaria and polymorphous light eruption (PLE) are acquired idiopathic photosensitivity disorders, but each phenomenon is extremely different; one is an immediate reaction, and one is a delayed-type reaction. Phototesting is necessary not only for the diagnosis of these photosensitivity disorders but also for the determination of the action spectrum so that the patient can try to avoid the triggering wavelengths in ordinary life. Solar urticaria is unique in that the particular spectra that inhibit or enhance the reactions by action spectra are present in some cases. In contrast, with PLE, phototesting is difficult, because a single or even repeated exposure of ultraviolet light or visible light sometimes fails to provoke the reaction. Here, we report a case of solar urticaria complicated with PLE. Solar urticaria with an action spectrum ranging from UVB to visible light was diagnosed by clinical presentation, phototesting and intradermal injections of photo-irradiated autologous serum. PLE induced by UVA was diagnosed by clinical presentation and phototesting. This article is protected by copyright. All rights reserved.

  10. NASA-UVa light aerospace alloy and structure technology program supplement: Aluminum-based materials for high speed aircraft

    NASA Technical Reports Server (NTRS)

    Starke, E. A., Jr.

    1993-01-01

    This report on the NASA-UVa Light Aerospace Alloy and Structure Technology Program Supplement: Aluminum-Based Materials for High Speed Aircraft covers the period from January 1, 1992 to June 30, 1992. The objective of the research is to develop aluminum alloys and aluminum matrix composites for the airframe which can efficiently perform in the HSCT environment for periods as long as 60,000 hours (certification for 120,000 hours) and, at the same time, meet the cost and weight requirements for an economically viable aircraft. Current industry baselines focus on flight at Mach 2.4. The research covers four major materials systems: (1) ingot metallurgy 2XXX, 6XXX, and 8XXX alloys, (2) powder metallurgy 2XXX alloys, (3) rapidly solidified, dispersion strengthened Al-Fe-X alloys, and (4) discontinuously reinforced metal matrix composites. There are ten major tasks in the program which also include evaluation and trade-off studies by Boeing and Douglas aircraft companies.

  11. Comparative study of the leaf volatiles of Arctostaphylos uva-ursi (L.) Spreng. and Vaccinium vitis-idaea L. (Ericaceae).

    PubMed

    Radulović, Niko; Blagojević, Polina; Palić, Radosav

    2010-09-02

    The first GC and GC/MS analyses of the essential oils hydrodistilled from dry leaves of Arctostaphylos uva-ursi and Vaccinium vitis-idaea enabled the identification of 338 components in total (90.4 and 91.7% of the total GC peak areas, respectively). Terpenoids, fatty acids, fatty acid- and carotenoid derived compounds were predominant in the two samples. Both oils were characterized by high relative percentages of α-terpineol and linalool (4.7-17.0%). Compositional data on the volatiles of the presently analyzed and some other Ericaceae taxa (literature data) were mutually compared by means of multivariate statistical analyses (agglomerative hierarchical cluster analysis and principal component analysis). This was done in order to determine, based on the essential oil profiles, possible mutual relationships of the taxa within the family, especially that of species from the genera Arctostaphylos and Vaccinium. Results of the chemical and statistical analyses pointed to a strong relation between the genera Vaccinium and Arctostaphylos.

  12. Insight into photocatalytic degradation of dissolved organic matter in UVA/TiO₂ systems revealed by fluorescence EEM-PARAFAC.

    PubMed

    Phong, Diep Dinh; Hur, Jin

    2015-12-15

    Photocatalytic degradation of dissolved organic matter (DOM) using TiO2 as a catalyst and UVA as a light source was examined under various experimental settings with different TiO2 doses, solution pH, and the light intensities. The changes in UV absorbance and fluorescence with the irradiation time followed a pseudo-first order model much better than those of dissolved organic carbon. In general, the degradation rates were increased by higher TiO2 doses and light intensities. However, the exact photocatalytic responses of DOM to the irradiation were affected by many other factors such as aggregation of TiO2, light scattering, hydroxyl radicals produced, and DOM sorption on TiO2. Fluorescence excitation-emission matrix (EEM) coupled with parallel factor analysis (PARAFAC) revealed that the DOM changes in fluorescence could be described by the combinations of four dissimilar components including one protein-like, two humic-like, and one terrestrial humic-like components, each of which followed well the pseudo-first order model. The photocatalytic degradation rates were higher for protein-like versus humic-like component, whereas the opposite order was displayed for the degradation rates in the absence of TiO2, suggesting different dominant mechanisms operating between the systems with and without TiO2. Our results based on EEM-PARAFAC provided new insights into the underlying mechanisms associated with the photocatalytic degradation of DOM as well as the potential environmental impact of the treated water. This study demonstrated a successful application of EEM-PARAFAC for photocatalytic systems via directly comparing the kinetic rates of the individual DOM components with different compositions.

  13. Accelerated Corneal Collagen Cross-Linking Using Topography-Guided UV-A Energy Emission: Preliminary Clinical and Morphological Outcomes

    PubMed Central

    Mazzotta, Cosimo; Traversi, Claudio; Baiocchi, Stefano; Fontana, Luigi

    2016-01-01

    Purpose. To assess the clinical and morphological outcomes of topography-guided accelerated corneal cross-linking. Design. Retrospective case series. Methods. 21 eyes of 20 patients with progressive keratoconus were enrolled. All patients underwent accelerated cross-linking using an ultraviolet-A (UVA) exposure with an energy release varying from 7.2 J/cm2 up to 15 J/cm2, according to the topographic corneal curvature. Uncorrected (UDVA) and corrected (CDVA) distance visual acuity, topography, in vivo confocal microscopy (IVCM), and anterior segment optic coherence tomography (AS-OCT) were evaluated preoperatively and at the 1, 3, 6, and 12 months postoperatively. Results. 12 months after surgery UDVA and CDVA did not significantly vary from preoperative values. The average topographic astigmatism decreased from −4.61 ± 0.74 diopters (D) to −3.20 ± 0.81 D and coma aberration improved from 0.95 ± 0.03 μm to 0.88 ± 0.04 μm after surgery. AS-OCT and IVCM documented differential effects on the treated areas using different energies doses. The depths of demarcation line and keratocyte apoptosis were assessed. Conclusions. Preliminary results show correspondence between the energy dose applied and the microstructural stromal changes induced by the cross-linking at various depths in different areas of treated cornea. One year after surgery a significant reduction in the topographic astigmatism and comatic aberration was detected. None of the patients developed significant complications. PMID:28018671

  14. Colour Changes on the Surface of the Rock Materials Due to UV-A and UV-B Rays

    NASA Astrophysics Data System (ADS)

    Binal, Adil; Ayderman, Aykut; Sel, Aylin

    2015-04-01

    The colour of the rocks used in the current buildings, and historical monuments is an important parameter in architecture and engineering. In addition, engineering geologists use the colour in order to identify the weathering class of rock material. The main colour of the stone, especially, are affected by the mineral size, the colour of the primary minerals and matrix material, as well as the colour of the accessory minerals. Due to atmospheric effects, changes in the outer surface colour of the rocks used as siding materials occur with over time. Factors causing the colour change are carbon dioxide (CO2), ozone (O3), sulphate (SO2, SO3) and nitrate (NOx) from the atmosphere with aerosols as well as UV rays from the sun. There is no more work in the literature on colour changes caused by UV-A and UV-B rays. In this study, the effects of ultraviolet in the colour of the surfaces of basalt, limestone, ignimbrite, travertine and sandstone have been simulated with a new experimental device in the laboratory medium. Lutron colour analyser (RGB-1002) was used for the measurements of RGB colours. Colour differences between the beginning and end of tests were determined with the standard practice for calculation of colour tolerances and colour differences from instrumentally measured colour coordinates (ASTM D2244). As a result of the experiments performed, lighten that seem on dark-grey micritic limestone (colour change ratio, CCR: 17.06) and basalt samples (CCR: 8.24) become even visually noticeable. Black and red ignimbrite samples having high porosity were presented the lower rate of colour changes. Finally, colour darkening has been observed in the light-coloured travertine (CCR: 13.8) and sandstone samples (CCR: 20.99).

  15. Corneal Cross-Linking with Riboflavin and UV-A in the Mouse Cornea in Vivo: Morphological, Biochemical, and Physiological Analysis

    PubMed Central

    Kling, Sabine; Hammer, Arthur; Conti, Alain; Hafezi, Farhad

    2017-01-01

    Purpose To morphologically, biochemically, and physiologically characterize corneal cross-linking with riboflavin and UV-A light (CXL) in a newly established in vivo murine model. Methods C57BL/6 wild-type mice (N = 67) were treated with various CXL protocols, with modification of the following parameters: total energy (fluence) used, duration of UV-A irradiation, continuous versus pulsed irradiation, and CXL under hypoxic conditions (contact lens). Corneas were evaluated biomicroscopically, histologically, and using optical coherence tomography. Conformational collagen changes were evaluated via changes in the speed of enzymatic digestion. Results A fluence of 5.4 J/cm2 induced scar formation, while fluences of < 0.18 J/cm2 induced neovascularization. Fluences between 1.62 and 2.7 J/cm2 reduced epithelial thickness, but maintained a transparent cornea after 1 month. Pulsed UV irradiation inhibited neovascularization, but favored scar formation. Changes in the speed of enzymatic digestion suggest that CXL in mice, when compared to humans, requires less UV-A energy than the difference in corneal thickness between the species would suggest. Conclusions We demonstrated the in vivo response of very strong and very weak CXL and identified the best suited range of UV fluence in murine corneas. The presented murine CXL model may be helpful in future research addressing cellular and molecular pathways associated to CXL treatment. Translational Relevance Adverse tissue reactions following CXL treatment were observed, if the administered UV energy was out of the treatment window—raising concern about novel CXL treatment protocols that have not been previously validated in an experimental setting. PMID:28149672

  16. Nrf2 deficiency causes lipid oxidation, inflammation, and matrix-protease expression in DHA-supplemented and UVA-irradiated skin fibroblasts.

    PubMed

    Gruber, Florian; Ornelas, Cayo Mecking; Karner, Susanne; Narzt, Marie-Sophie; Nagelreiter, Ionela Mariana; Gschwandtner, Maria; Bochkov, Valery; Tschachler, Erwin

    2015-11-01

    Fish oil rich in docosahexaenoic acid (DHA) has beneficial effects on human health. Omega-3 polyunsaturated fatty acids are precursors of eicosanoids and docosanoids, signaling molecules that control inflammation and immunity, and their dietary uptake improves a range of disorders including cardiovascular diseases, ulcerative colitis, rheumatoid arthritis, and psoriasis. The unsaturated nature of these fatty acids, however, makes them prone to oxidation, especially when they are incorporated into (membrane) phospholipids. The skin is an organ strongly exposed to oxidative stress, mainly due to solar ultraviolet radiation. Thus, increased levels of PUFA in combination with oxidative stress could cause increased local generation of oxidized lipids, whose action spectrum reaches from signaling molecules to reactive carbonyl compounds that can crosslink biomolecules. Here, we investigated whether PUFA supplements to fibroblasts are incorporated into membrane phospholipids and whether an increase of PUFA within phospholipids affects the responses of the cells to UV exposure. The redox-sensitive transcription factor Nrf2 is the major regulator of the fibroblast stress response to ultraviolet radiation or exposure to oxidized lipids. Here we addressed how Nrf2 signaling would be affected in PUFA-supplemented human dermal fibroblasts and mouse dermal fibroblasts from Nrf2-deficient and wild type mice. We found, using HPLC-tandem MS, that DHA supplements to culture media of human and murine fibroblasts were readily incorporated into phospholipids and that subsequent irradiation of the supplemented cells with UVA resulted in an increase in 1-palmitoyl-2-(epoxyisoprostane-E2)-sn-glycero-3-phosphorylcholine and Oxo-DHA esterified to phospholipid, both of which are Nrf2 agonists. Also, induction of Nrf2 target genes was enhanced in the DHA-supplemented fibroblasts after UVA irradiation. In Nrf2-deficient murine fibroblasts, the expression of the target genes was, as expected

  17. Effect of preillumination with red light on photosynthetic parameters and oxidant-/antioxidant balance in Arabidopsis thaliana in response to UV-A.

    PubMed

    Kreslavski, Vladimir D; Shirshikova, Galina N; Lyubimov, Valery Yu; Shmarev, Alexander N; Boutanaev, Alexander M; Kosobryukhov, Anatoly A; Schmitt, Franz-Josef; Friedrich, Thomas; Allakhverdiev, Suleyman I

    2013-10-05

    The effect of preillumination with low intensity (10μmol quanta m(-2)s(-1), 10min) light of different wavelengths in the spectral range of 550-730nm on photosynthesis and activity of PSII, the content of photosynthetic pigments and H2O2, as well as the peroxidase activity in the leaves of 26-d-old Arabidopsis thaliana wild-type (WT) plants in response to UV-A radiation was studied. UV-A decreased the activity of the PSII, the content of Chl a, Chl b and carotenoids, as well as increased the peroxidase activity and H2O2 level in the WT leaves. Preillumination of the leaves with red light (RL, λmax=664nm) reduced the inhibitory effect of UV radiation on photosynthesis and activity of the PSII, indicated by delayed light emission as well as the H2O2 level, but increased the peroxidase activity in the leaves compared to illumination by UV radiation only. Illumination with RL alone and the subsequent exposure of plants to darkness increased the peroxidase activity and the transcription activity of genes of the transcription factors APX1 and HYH. Preillumination of leaves with RL, then far red light (FRL, λmax=727nm) partially compensated the effect of the RL for all studied parameters, suggesting that the active form of phytochrome (PFR) is involved in these processes. Preillumination with the wavelengths of 550, 594 and 727nm only did not have a marked effect on photosynthesis. The hy2 mutant of Arabidopsis with reduced synthesis of the phytochrome B chromophore showed decreased resistance of PSII to UV-A compared with the WT of Arabidopsis. UV radiation reduced Chl a fluorescence much faster in the hy2 mutant compared to the WT. Preillumination of the hy2 mutant with RL did not affect the PSII activity and H2O2 level in UV-irradiated leaves. It is assumed that the formation of the increased resistance of the photosynthetic apparatus of Arabidopsis to UV-A radiation involves PFR and the antioxidant system of plants, partly by inducing transcriptional activity of

  18. Overexpression of phospholipid-hydroperoxide glutathione peroxidase in human dermal fibroblasts abrogates UVA irradiation-induced expression of interstitial collagenase/matrix metalloproteinase-1 by suppression of phosphatidylcholine hydroperoxide-mediated NFkappaB activation and interleukin-6 release.

    PubMed

    Wenk, Jutta; Schüller, Jutta; Hinrichs, Christina; Syrovets, Tatjana; Azoitei, Ninel; Podda, Maurizio; Wlaschek, Meinhard; Brenneisen, Peter; Schneider, Lars-A; Sabiwalsky, Andrea; Peters, Thorsten; Sulyok, Silke; Dissemond, Joachim; Schauen, Matthias; Krieg, Thomas; Wirth, Thomas; Simmet, Thomas; Scharffetter-Kochanek, Karin

    2004-10-29

    Phospholipid-hydroperoxide glutathione peroxidase (PHGPx) exhibits high specific activity in reducing phosphatidylcholine hydroperoxides (PCOOHs) and thus may play a central role in protecting the skin against UV irradiation-triggered detrimental long term effects like cancer formation and premature skin aging. Here we addressed the role of PHGPx in the protection against UV irradiation-induced expression of matrix metalloproteinase-1 (MMP-1). For this purpose, we created human dermal fibroblast cell lines overexpressing human PHGPx. Overexpression led to a significant increase in PHGPx activity. In contrast to a maximal 4.5-fold induction of specific MMP-1 mRNA levels in vector-transfected cells at 24 h after UVA irradiation, no MMP-1 induction occurred at any studied time point after UVA treatment of PHGPx-overexpressing fibroblasts. As interleukin-6 (IL-6) was earlier shown to mediate the UVA induction of MMP-1, we studied whether PHGPx overexpression might interfere with the NFkappaB-mediated IL-6 induction and downstream signaling. Using transient transfections of IL-6 promoter constructs containing NFkappaB binding sites, we observed a high induction of the reporter gene luciferase in vector-transfected control cells and a significantly lower induction in PHGPx-overexpressing fibroblasts following UVA irradiation. Consistently both UVA irradiation and treatment of fibroblasts with PCOOHs led to phosphorylation and nuclear translocation of the p65 subunit, whereas cells overexpressing PHGPx exhibited impaired NFkappaB activation, p65 phosphorylation, and nuclear translocation. In line with this, the PHGPx-overexpressing fibroblasts showed a reduced constitutive and UVA irradiation-induced IL-6 release. After incubating PHGPx-overexpressing cells with PCOOHs a reduced induction of IL-6 was observed. This together with the suppression of UVA irradiation-induced IL-6 release in the presence of Trolox, a chain breaker of PCOOH-initiated lipid peroxidation

  19. IL-1 receptor antagonist attenuates MAP kinase/AP-1 activation and MMP1 expression in UVA-irradiated human fibroblasts induced by culture medium from UVB-irradiated human skin keratinocytes.

    PubMed

    Wang, Xiaoyong; Bi, Zhigang; Chu, Wenming; Wan, Yinsheng

    2005-12-01

    Solar UV light comprises UVB wavelengths (290-320 nm) and UVA wavelengths (320-400 nm). UVB radiation reaches the epidermis and, to a lesser extent, the upper part of the dermis, while UVA radiation penetrates more deeply into human skin. Existing studies have demonstrated that UV-irradiated epidermal keratinocytes release cytokines that indirectly promote MMP-1 production in dermal fibroblasts. In this study, we first investigated the effect of IL-1 on MAPK activity, c-Jun and c-Fos mRNA expression, and MMP-1 and MMP-2 production in UVA-irradiated human dermal fibroblasts. The results showed that UVA irradiation dose-dependently increased MMP-1 but not MMP-2 production in human skin fibroblasts. IL-1alpha and IL-1beta promoted MMP-1 but not MMP-2 production in UVA-irradiated fibroblasts. Both IL-1alpha and IL-1beta activated MAP kinase, significantly elevating c-Jun and c-Fos mRNA expression. We then investigated the indirect effect of UVB-irradiated keratinocyte culture medium on MMP-1 production in UVA-irradiated primary cultured human dermal fibroblasts and the effect of IL-1Ra. The results showed that cell culture medium from UVB-irradiated keratinocytes increased MMP-1 production in UVA-irradiated fibroblasts, and IL-1Ra dose-dependently inhibited MMP-1 production. IL-1Ra dose-dependently inhibited c-Jun mRNA expression of fibroblasts with no significant effect on c-Fos mRNA expression. These results demonstrate that UVB-irradiated keratinocytes promoted MMP-1 production in UVA-irradiated fibroblasts in a paracrine manner while IL-1Ra reduced MMP-1 production through inhibiting c-Jun mRNA expression. Collectively, our data suggest that IL-1 plays an important role in the dermal collagen degradation associated with UV-induced premature aging of the skin and IL-1Ra may be applied for the prevention and treatment of photoaging.

  20. [Effect of long-wave ultraviolet light (UV-A) and medium-wave ultraviolet rays (UV-B) on human skin. Critical comparison].

    PubMed

    Raab, W

    1980-04-15

    When discussing the effects of ultraviolet radiation on human skin, one should carefully distinguish between the long wave ultraviolet light (UV-A) and the short wave radiations (UV-B and UV-C). Ultraviolet A induces immediate pigmentation but, if high energies are applied, a permanent pigmentation is elicited. This type of ultraviolet A-induced pigmentation has been called "spontaneous" pigmentation as no erythematous reaction is necessary to induce or accelerate melanine formation. Ultraviolet B provokes erythema and consecutive pigmentation. Upon chronic exposure, ultraviolet B causes the wellknown actinic damage of the skin and even provokes carcinoma. With exposures to the sunlight (global radiation), one should be most careful. The public must be informed extensively about the dangers of excessive sunbaths. The use of artificial "suns" with spectra between 260 and 400 nm is limited as it may cause the same type of damage as the global radiation. An exact schedule for use of artificial lamps is strongly recommended. After one cycle of exposures, an interruption is necessary until the next cycle of irradiations may start. Upon continual use for tanning of the skin, artificial lamps may provoke irreversible damage of the skin. Radiation sources with emission spectra of wavelengths between 315 and 400 nm exclusively are well suited for the induction of skin pigmentation (cosmetic use). Potent radiation such as UVASUN systems provoke a "pleasant" permanent pigmentation after exposures for less than one hour. The use of ultraviolet A (UV-A) does not carry any risk for the human skin.

  1. NASA-UVA Light Aerospace Alloy and Structures Technology Program (LA2ST). Research on Materials for the High Speed Civil Transport

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.; Starke, Edgar A., Jr.; Kelly, Robert G.; Scully, John R.; Stoner, Glenn E.; Wert, John A.

    1997-01-01

    Since 1986, the NASA-Langley Research Center has sponsored the NASA-UVa Light Alloy and Structures Technology (LA2ST) Program at the University of Virginia (UVa). The fundamental objective of the LA2ST program is to conduct interdisciplinary graduate student research on the performance of next generation, light-weight aerospace alloys, composites and thermal gradient structures. The LA2ST program has aimed to product relevant data and basic understanding of material mechanical response, environmental/corrosion behavior, and microstructure; new monolithic and composite alloys; advanced processing methods; measurement and modeling advances; and a pool of educated graduate students for aerospace technologies. The scope of the LA2ST Program is broad. Research areas include: (1) Mechanical and Environmental Degradation Mechanisms in Advanced Light Metals and Composites, (2) Aerospace Materials Science, (3) Mechanics of materials for Aerospace Structures, and (4) Thermal Gradient Structures. A substantial series of semi-annual progress reports issued since 1987 documents the technical objectives, experimental or analytical procedures, and detailed results of graduate student research in these topical areas.

  2. Effect of prestorage UV-A, -B, and -C radiation on fruit quality and anthocyanin of 'Duke' blueberries during cold storage.

    PubMed

    Nguyen, Chau T T; Kim, Jeongyun; Yoo, Kil Sun; Lim, Sooyeon; Lee, Eun Jin

    2014-12-17

    Ultraviolet (UV)-A, -B, and -C were radiated to full-ripe blueberries (cv. 'Duke'), and their effects on fruit qualities and phytonutrients during subsequent cold storage were investigated. The blueberries were exposed to each UV light at 6 kJ/m(2) and then stored at 0 °C for 28 days. Weight loss and decay of the fruits after UV treatment were significantly decreased during the cold storage. The total phenolics and antioxidant activities of blueberries after UV-B and -C treatments were always higher than those of the control and UV-A treatment. Individual anthocyanins were markedly increased during the 3 h after the UV-B and -C treatments. The correlation matrix between total phenolics, anthocyanins, and antioxidant activity measured by the 2,2'-azinobis(3-ethylbenzthiazoline-6-sulfonic acid) assay indicated a significantly close correlation with the individual anthocyanin contents. It was confirmed that the prestorage treatments of UV-B and -C increased the storability and phytochemical accumulation of the full-ripe 'Duke' blueberries during cold storage.

  3. Effects of ultraviolet radiation (UVA+UVB) and copper on the morphology, ultrastructural organization and physiological responses of the red alga Pterocladiella capillacea.

    PubMed

    Schmidt, Éder C; Kreusch, Marianne; Felix, Marthiellen R de L; Pereira, Debora T; Costa, Giulia B; Simioni, Carmen; Ouriques, Luciane C; Farias-Soares, Francine L; Steiner, Neusa; Chow, Fungyi; Ramlov, Fernanda; Maraschin, Marcelo; Bouzon, Zenilda L

    2015-01-01

    The effect of ultraviolet (UV) radiation and copper (Cu) on apical segments of Pterocladiella capillacea was examined under two different conditions of radiation, PAR (control) and PAR+UVA+UVB (PAR+UVAB), and three copper concentrations, ranging from 0 (control) to 0.62, 1.25 and 2.50 μm. Algae were exposed in vitro to photosynthetically active radiation (PAR) at 70 μmol photons m(-2)  s(-1) , PAR + UVB at 0.35 W m(-2) and PAR +UVA at 0.70 W m(-2) during a 12-h photocycle for 3 h each day for 7 days. The effects of radiation and copper on growth rates, content of photosynthetic pigments and photosynthetic performance were analyzed. In addition, samples were processed for light and transmission electron microscopy. The content of photosynthetic pigments decreased after exposure to radiation and Cu. Compared with PAR radiation and copper treatments modified the kinetics patterns of the photosynthesis/irradiance curve. The treatments also caused changes in the ultrastructure of cortical and subcortical cells, including increased cell wall thickness and accumulation of plastoglobuli, as well as changes in the organization of chloroplasts. The results indicate that the synergistic interaction between UV radiation and Cu in P. capillacea, led to the failure of protective mechanisms and causing more drastic changes and cellular imbalances.

  4. An approach to utilize the artificial high power LED UV-A radiation in photoreactors for the degradation of methylene blue.

    PubMed

    Betancourt-Buitrago, L A; Vásquez, C; Veitia, L; Ossa-Echeverry, O; Rodriguez-Vallejo, J; Barraza-Burgos, J; Marriaga-Cabrales, N; Machuca-Martínez, F

    2017-01-18

    Utilization of UV LED light is trending in the development of photoreactors for pollutant treatment. In this study, two different geometries were studied in the degradation of methylenebBlue (MB) using high power UVA LED as a source of light. The dosage, initial concentration, electric power, and H2O2 addition were evaluated in the two geometries: a mini CPC (Cilindrical Parabolic Collector) and a vertical cylindrical with external irradiation both coupled with LED UVA. Best degradation was obtained for 0.3 g L(-1) TiO2, 40 min, and 15 ppm of MB of initial concentration in the standard batch reactor. It was found that the best system was a cpc geometry. Also, hydrogen peroxide was used as an electron acceptor and 97% degradation was obtained in 30 min with 10 mM H2O2 and 0.4 g TiO2/L. Power of the LEDs was also evaluated and it was found that 20 W m(-2) is the best operational condition to achieve the best MB degradation avoiding the oxidant species recombination.

  5. Effects of solar UV-A and UV-B radiation on gene expression and phenolic accumulation in Betula pendula leaves.

    PubMed

    Morales, Luis O; Tegelberg, Riitta; Brosché, Mikael; Keinänen, Markku; Lindfors, Anders; Aphalo, Pedro J

    2010-07-01

    Ultraviolet (UV) radiation is an important environmental factor for plant communities; however, plant responses to solar UV are not fully understood. Here, we report differential effects of solar UV-A and UV-B radiation on the expression of flavonoid pathway genes and phenolic accumulation in leaves of Betula pendula Roth (silver birch) seedlings grown outdoors. Plants were exposed for 30 days to six UV treatments created using three types of plastic film. Epidermal flavonoids measured in vivo decreased when UV-B was excluded. In addition, the concentrations of six flavonoids determined by high-performance liquid chromatography-mass spectrometry declined linearly with UV-B exclusion, and transcripts of PAL and HYH measured by quantitative real-time polymerase chain reaction were expressed at lower levels. UV-A linearly regulated the accumulation of quercetin-3-galactoside and quercetin-3-arabinopyranoside and had a quadratic effect on HYH expression. Furthermore, there were strong positive correlations between PAL expression and accumulation of four flavonols under the UV treatments. Our findings in silver birch contribute to a more detailed understanding of plant responses to solar UV radiation at both molecular and metabolite levels.

  6. Studies of DNA and chromosome damage in skin fibroblasts and blood lymphocytes from psoriasis patients treated with 8-methoxypsoralen and UVA irradiation

    SciTech Connect

    Bredberg, A.; Lambert, B.; Lindblad, A.; Swanbeck, G.; Wennersten, G.

    1983-08-01

    Exposure of human lymphocytes and skin fibroblasts in vitro to a single, clinically used dose of PUVA, i.e., 0.1 micrograms/ml of 8-methoxypsoralen (8-MOP) plus 0.9-4 J/cm2 of longwave ultraviolet radiation (UVA), lead to the formation of DNA damage as determined by alkaline elution, and to chromosome aberrations and sister chromatid exchanges (SCE). When lymphocyte-enriched plasma was obtained from psoriasis patients 2 h after oral intake of 8-MOP and then UVA irradiated (1.8-3.6 J/cm2) in vitro, an increased frequency of chromosome aberrations and SCE was observed. Normal levels of chromosome aberrations and SCE were found in lymphocytes of psoriasis patients after 3-30 weeks of PUVA treatment in vivo. A small but statistically significant increase in the SCE frequency was observed in the lymphocytes of psoriasis patients treated for 1-6 years with PUVA (mean 18.0 SCE/cell) as compared with before PUVA (mean 15.8, p less than 0.05). Skin fibroblasts of psoriasis patients analyzed 5 years after the start of PUVA treatment showed a normal number of SCE but a high fraction of filter-retained DNA in the alkaline elution assay, suggesting the presence of cross-linked DNA.

  7. Enhanced coagulation-photocatalytic treatment of Acid red 73 dye and real textile wastewater using UVA/synthesized MgO nanoparticles.

    PubMed

    Jorfi, Sahand; Barzegar, Gelavizh; Ahmadi, Mehdi; Darvishi Cheshmeh Soltani, Reza; Alah Jafarzadeh Haghighifard, Nemat; Takdastan, Afshin; Saeedi, Reza; Abtahi, Mehrnoosh

    2016-07-15

    Sequencing coagulation - photocatalytic degradation using UVA/MgO nanoparticles process was investigated for Acid red 73dye removal and then treatment of a real textile wastewater. Effective operational parameters including pH and coagulant and photocatalyst dosage were studied in synthetic wastewater and then the process was applied for real wastewater. Both coagulation and photocatalytic processes were pH dependent. At coagulant dosage of 200 mg/L and initial pH of 6, the dye concentration decreased from 200 to 31 mg/L. Complete removal of AR73 was observed with MgO nanoparticles of 0.8 g/L, initial pH of 5 and reaction time of 60 min. Langmuir-Hinshelwood model was well fitted with removal results (R(2): 0.939-0.988 for different initial dye concentration). In the case of real textile wastewater, the sequence coagulation-UVA/MgO nanoparticles photocatalytic degradation yielded considerable total COD and TOC removal 98.3% and 86.9%respectively, after 300 min.

  8. Effects of zinc oxide and titanium dioxide nanoparticles on green algae under visible, UVA, and UVB irradiations: no evidence of enhanced algal toxicity under UV pre-irradiation.

    PubMed

    Lee, Woo-Mi; An, Youn-Joo

    2013-04-01

    Some metal oxide nanoparticles are photoreactive, thus raising concerns regarding phototoxicity. This study evaluated ecotoxic effects of zinc oxide nanoparticles and titanium dioxide nanoparticles to the green algae Pseudokirchneriella subcapitata under visible, UVA, and UVB irradiation conditions. The nanoparticles were prepared in algal test medium, and the test units were pre-irradiated by UV light in a photoreactor. Algal assays were also conducted with visible, UVA or UVB lights only without nanoparticles. Algal growth was found to be inhibited as the nanoparticle concentration increased, and ZnO NPs caused destabilization of the cell membranes. We also noted that the inhibitory effects on the growth of algae were not enhanced under UV pre-irradiation conditions. This phenomenon was attributed to the photocatalytic activities of ZnO NPs and TiO2 NPs in both the visible and UV regions. The toxicity of ZnO NPs was almost entirely the consequence of the dissolved free zinc ions. This study provides us with an improved understanding of toxicity of photoreactive nanoparticles as related to the effects of visible and UV lights.

  9. Statistical analysis and inter-comparison of the solar UVB, UVA and global radiation for Beer Sheva and Neve Zohar (Dead Sea), Israel

    NASA Astrophysics Data System (ADS)

    Kudish, A. I.; Lyubansky, V.; Evseev, E. G.; Ianetz, A.

    2005-02-01

    A statistical analysis and inter-comparison of the solar UVB, UVA and global radiation for Beer Sheva and Neve Zohar (Dead Sea) are presented utilizing data measured from January 1995 through December 2002. Beer Sheva is located approximately 65 km to the west of and ˜700 m above Neve Zohar. The monthly average hourly and daily values for all radiation types at both sites are reported. The standard errors of the monthly average daily values have been calculated in order to ascertain whether the average daily radiation intensities are representative, i.e. if the magnitude of the standard error is less than the inherent measurement uncertainty of the instruments, and, thereby, justify an inter-comparison between the two sites. The relative magnitude of the global, UVB and UVA radiation intensity at the two sites is attributed to the enhanced scattering of the incident solar radiation at the Dead Sea location due to the longer optical path length it must traverse to arrive at the Dead Sea, the lowest terrestrial point on earth. The degree of attenuation of solar radiation due to the scattering phenomena is inversely proportional to the wavelength raised to some power and, consequently, it is greatest for UVB and negligible for global radiation.

  10. UVA and visible light photons produce frank strand breaks in human P3 cell DNA as well as a new class of alkali-labile lesion

    SciTech Connect

    Peak, M.J.; Peak, J.G.

    1994-05-01

    Human P3 epithelioid cells were exposed to UVA (290--400 nm), as well as to blue and green photons in the 400--520 mm region of the spectrum, and the production of strand breaks in their DNA was measured by using elution. After exposure to blue photons the profiles were convex (downturning), shown to be due to the induction of a mixture of frank single-strand DNA breaks (SSB) plus rapidly developing alkali-labile sites (ALS). as well as latent breaks that develop during the first 6 h of the elution, termed slowly developing alkali-labile sites (SDALS). A significant proportion of the lesions produced by P3 cells by blue light photons are SDALS, whereas green light photons at 520 nm and UVA photons at 365 nm produce no SDALS and the elution profiles are exponential. This is also the case for Chinese hamster ovary cells exposed to 405 nm, evidence that a unique chromophore in P3 cells that absorbs strongly in the blue region leads to the formation of SDALS. The similarity in induction of SDALS at 460 and 405 nm is evidence that the chromophore is not a porphyrin, because these compounds have sharp absorption maxima in the lower 400 nm region. The chemical nature of these lesions as well as the cellular responses to them remain enigmatic.

  11. Content Analysis Schedule for Bilingual Education Programs: BICEP Intercambio de la Cultura.

    ERIC Educational Resources Information Center

    Shore, Marietta Saravia; Nafus, Charles

    This content analysis schedule for BICEP Intercambio de la Cultura (San Bernardino, California), presents information on the history, funding, and scope of the project. Included are sociolinguistic process variables such as the native and dominant languages of students and their interaction. Information is provided on staff selection and the…

  12. Experiences of Serveis de Cultura Popular in the Field of Co-Production and Exchange.

    ERIC Educational Resources Information Center

    Tuni, Lluis

    1992-01-01

    Describes efforts of Serveis de Cultura Popular, a nonprofit foundation in Barcelona (Spain), in the coproduction of educational videos. Highlights include contests that awarded prizes for completed videos, video scripts, or ideas for videos; coproduction with educational television; coproduction of an interactive videodisc; and international…

  13. Giving a Virtual Voice to the Silent Language of Culture: The "Cultura" Project.

    ERIC Educational Resources Information Center

    Furstenberg, Gilberte; Levet, Sabine; English, Kathryn; Maillet, Katherine

    2001-01-01

    Presents a Web-based, cross-cultural, curricular initiative entitled, "Cultura," designed to develop foreign language students' understanding of foreign cultural attitudes, concepts, beliefs, and ways of interacting and looking at the world. Focuses on the pedagogy of electronic media, with particular emphasis on the ways the Web can be used to…

  14. N-terminal 5-mer peptide analog P165 of amyloid precursor protein inhibits UVA-induced MMP-1 expression by suppressing the MAPK pathway in human dermal fibroblasts.

    PubMed

    Wang, Ying; Chen, Hui; Wang, Wen; Wang, Rong; Liu, Zi-Lian; Zhu, Wei; Lian, Shi

    2014-07-05

    Exposure to ultraviolet (UV) radiation leads to a progressive increase in dermal damage through the degradation of collagen, which is mediated by matrix metalloproteinases (MMPs). UV radiation alters the intracellular signaling events that regulate the elaboration of MMPs. Our previous study showed that P165, the N-terminal 5-mer peptide analog of amyloid precursor protein, exerts a protective effect on ultraviolet A (UVA)-induced loss of collagen type I in human dermal fibroblasts (HDFs) by inhibiting the generation of intracellular reactive oxygen species and MMP-1. In this study, we focused on specific signal transduction pathways to elucidate the possible photoprotective mechanisms of P165 in controlling MMP-1 inhibition. Results from western blot analyses indicated that pretreatment with P165 dose-dependently inhibited UVA-induced phosphorylation of extracellular regulated protein kinases (ERK), c-Jun N-terminal kniase (JNK), p38 mitogen-activated protein kinases (MAPKs), and the phosphorylation of their downstream targets c-Jun and c-Fos. The photoprotective effects of P165 were further demonstrated in collagen type I secretion and cellular senescence induced by UVA irradiation. These findings suggest that P165 exerts photoprotective activity in UVA-treated HDFs by regulating MMP-1 generation. This activity may be mediated by inhibiting the MAPK signaling pathways. Thus, P165 is a potential agent for the prevention of skin photoaging.

  15. Reference gene validation for qPCR on normoxia- and hypoxia-cultured human dermal fibroblasts exposed to UVA: is β-actin a reliable normalizer for photoaging studies?

    PubMed

    Brugè, F; Venditti, E; Tiano, L; Littarru, G P; Damiani, E

    2011-12-10

    Data normalization of gene expression on human dermal fibroblasts (HDF) exposed to UVA has commonly been done using either GAPDH or β-actin as reference genes without any validation of their expression stability. Since this aspect, important for accurate normalization, has been overlooked, we aimed to establish a suitable set of reference genes for studies on UVA-treated HDF cultured under both standard atmospheric oxygen tension (normoxia, 21%) and under a physiological, low oxygen tension for these cells (hypoxia, 5%). The stability of six commonly used reference genes was assessed using the geNorm and NormFinder softwares subsequent to reverse-transcription quantitative real-time PCR (RT-qPCR). GAPDH/SDHA were found to be the most stable genes under normoxia, while SDHA/TBP or HPRT1/β2M were the most stable ones under hypoxia in HDF exposed to 18 J/cm(2) UVA. β-Actin was always the most unstable reference gene. To emphasize the importance of selecting the most stably expressed reference genes for obtaining reliable results, mRNA expression levels of MMP-1 and COL1A1 were analyzed vs the best reference genes and the worst one. These reference genes are hence recommended for future qPCR analyses in studies concerning photo-damage on UVA-treated HDF.

  16. Scleral Cross-Linking Using Riboflavin UVA Irradiation for the Prevention of Myopia Progression in a Guinea Pig Model: Blocked Axial Extension and Altered Scleral Microstructure

    PubMed Central

    Wang, Bingjie; Lin, Xiao; Wu, Yi; Liu, Hong; Qu, Xiaomei; Dai, Jinhui; Zhou, Xingtao; Zhou, Hao

    2016-01-01

    Purpose To develop methods of collagen cross-linking (CXL) in the sclera for the treatment of progressive myopia and to investigate the biomechanical and histological changes that occur in as a result. Methods Twenty 14-day-old guinea pigs were divided into 3 groups: the cross-linking group (CL, n = 8), non cross-linking group (NCL, n = 8), and control group (n = 4). The scleras of the right eyes of the guinea pigs in the CL group were surgically exposed and riboflavin was dropped onto the irradiation zone for 20 seconds prior to ultraviolet-A (UVA) irradiation. The same procedure was conducted on the NCL group but without UVA irradiation. No procedure was conducted on the control group. The right eyes of the guinea pigs in the CL and NCL groups were then fitted with -10.00DS optics for six weeks. Retinoscopy and the axial lengths (AXL) were measured at baseline, and at the second, fourth and sixth weeks post-treatment in all three groups. All animal subjects were euthanized after the sixth week and then biomechanical and histopathological examinations of the scleras were conducted. Results The mean AXL of the NCL group was longer than both the control and CL groups at six weeks (P = 0.001). The mean refractive error in the NCL group was statistically significantly more negative than both the control and the CL groups at six weeks (P = 0.001). The scleral collagen fiber arrangements of the CL and control groups were denser and more regularly distributed than the NCL group. Ultimate stress of the sclera was lowest in the NCL group, followed by the CL then the control group (P<0.05). Ultimate strain (%) of the sclera was lowest in the CL group followed by the NCL and then the control group (P<0.05). Conclusion Our study demonstrates that scleral CXL using riboflavin UVA irradiation effectively prevents the progression of myopia by increasing scleral biomechanical strength in a guinea pig model. PMID:27829051

  17. Fullerene-C60/liposome complex: Defensive effects against UVA-induced damages in skin structure, nucleus and collagen type I/IV fibrils, and the permeability into human skin tissue.

    PubMed

    Kato, Shinya; Aoshima, Hisae; Saitoh, Yasukazu; Miwa, Nobuhiko

    2010-01-21

    We previously reported biological safety of fullerene-C60 (C60) incorporated in liposome consisting of hydrogenated lecithin and glycine soja sterol, as Liposome-Fullerene (0.5% aqueous phase; a particle size, 76nm; Lpsm-Flln), and its cytoprotective activity against UVA. In the present study, Lpsm-Flln was administered on the surface of three-dimensional human skin tissue model, rinsed out before each UVA-irradiation at 4 J/cm(2), and thereafter added again, followed by 19-cycle-repetition for 4 days (sum: 76 J/cm(2)). UVA-caused corneum scaling and disruption of epidermis layer were detected by scanning electron microscopy. Breakdown of collagen type I/IV, DNA strand cleavage and pycnosis/karyorrhexis were observed in vertical cross-sections of UVA-irradiated skin models visualized with fluorescent immunostain or Hoechst 33342 stain. These skin damages were scarcely repressed by liposome alone, but appreciably repressed by Lpsm-Flln of 250 ppm, containing 0.75 ppm of C60-equivalent to a 1/3300-weight amount vs. the whole liposome. Upon administration with Lpsm-Flln [16.7 microM (12 ppm): C60-equivalent] on human abdomen skin biopsies mounted in Franz diffusion cells, C60 permeated after 24h into the epidermis at 1.86 nmol/g tissue (1.34 ppm), corresponding to 0.3% of the applied amount and a 9.0-fold dilution rate, but C60 was not detected in the dermis by HPLC, suggesting no necessity for considering a toxicity of C60 due to systemic circulation via dermal veins. Thus Lpsm-Flln has a potential to be safely utilized as a cosmetic anti-oxidative ingredient for UVA-protection.

  18. UV-A light induces anthocyanin biosynthesis in a manner distinct from synergistic blue + UV-B light and UV-A/blue light responses in different parts of the hypocotyls in turnip seedlings.

    PubMed

    Wang, Yu; Zhou, Bo; Sun, Mei; Li, Yuhua; Kawabata, Saneyuki

    2012-08-01

    The effects of irradiating blue, UV-A, UV-B and a combination of the lights on anthocyanin accumulation at different hypocotyl positions were investigated in seedlings of the purple top turnip 'Tsuda'. The location of anthocyanin accumulation varied depending on different light spectra. Stronger accumulation of anthocyanin was induced (i) at the upper hypocotyl positions by blue light; (ii) mainly at the upper position, but also at the middle position by UV-B light; and (iii) at the upper to lower position by UV-A light. There were synergistic effects between blue and UV-B, while such effects were not observed for the other light combinations. Among the six chalcone synthase (CHS) genes identified in the 'Tsuda' turnip, BrCHS1, 4 and 5 exhibited light-dependent expression patterns, while the other three showed no apparent light responses. The expression of BrCHS1, 4 and 5 was increased particularly by UV-A and blue + UV-B irradiation at the middle to lower hypocotyl positions, in accordance with anthocyanin accumulation patterns. The highest induction of gene expression was observed for BrCHS4 upon blue + UV-B co-irradiation. In contrast, CHS expression was induced only slightly at higher hypocotyl positions by blue light. The R2R3-type MYB transcription factor genes PAP1, MYB4, MYB12 and MYB111 exhibited differential expression patterns at different hypocotyl positions; these patterns were unique for different light spectra. These unique anthocyanin accumulation patterns and gene expression profiles depending on hypocotyl positions and light sources demonstrate that there is a distinct UV-A response, blue + UV-B synergistic response and blue/UV-A light response for anthocyanin biosynthesis in turnip. UV-A light-dependent anthocyanin biosynthesis appeared to be regulated in a manner that is distinct from that mediated by cryptochromes and UV-B photoreceptors.

  19. Effects of UVA irradiation, aryl azides, and reactive oxygen species on the orthogonal inactivation of the human immunodeficiency virus (HIV-1)

    SciTech Connect

    Belanger, Julie M.; Raviv, Yossef; Viard, Mathias; Cruz, M. Jason de la; Nagashima, Kunio; Blumenthal, Robert

    2011-08-15

    Previously we reported that hydrophobic aryl azides partition into hydrophobic regions of the viral membrane of enveloped viruses and inactivate the virus upon UVA irradiation for 2 min. Prolonged irradiation (15 min) resulted in viral protein aggregation as visualized via Western blot analysis, due to reactive oxygen species (ROS) formation, with preservation of the surface antigenic epitopes. Herein, we demonstrate that these aggregates show detergent resistance and that this property may be useful towards the creation of a novel orthogonal virus inactivation strategy for use in preparing experimental vaccines. When ROS-modified HIV virus preparations were treated with 1% Triton X-100, there was an increase in the percent of viral proteins (gp41, p24) in the viral pellet after ultracentrifugation through sucrose. Transmission electron microscopy (TEM) of these detergent-resistant pellets shows some recognizable virus fragments, and immunoprecipitation studies of the gp41 aggregates suggest the aggregation is covalent in nature, involving short-range interactions.

  20. BAC-EDTA transepithelial riboflavin-UVA crosslinking has greater biomechanical stiffening effect than standard epithelium-off in rabbit corneas.

    PubMed

    Torricelli, Andre A M; Ford, Matthew R; Singh, Vivek; Santhiago, Marcony R; Dupps, William J; Wilson, Steven E

    2014-08-01

    Studies suggest that standard corneal collagen crosslinking (CXL) is a safe and effective treatment to stiffen the cornea for keratoconus and other ectatic corneal disorders. The purpose of the present study was to compare the biomechanical effects of transepithelial benzalkonium chloride-EDTA (BAC-EDTA) riboflavin-UVA crosslinking to standard epithelium-off riboflavin-UVA crosslinking in a rabbit model. Corneal stiffness was quantified using optical coherence elastography at two months after treatment. The mean lateral-to-axial displacement ratio for the BAC-EDTA transepithelial CXL group was lower (greater stiffness) [0.062 ± 0.042, mean ± SD] than epithelium-off CXL (mean ± SD: 0.065 ± 0.045) or untreated control eyes (0.069 ± 0.044). Using ANOVA with Tukey correction, a statistically significant difference was found between the BAC-EDTA transepithelial CXL group and standard epithelium-off CXL (p = 0.0019) or the untreated control (p < 0.0001) groups. A graph of the probability density functions for biomechanical stiffness also showed a greater shift in stiffening in the BAC-EDTA transepithelial CXL group than the standard epithelium-off CXL or untreated control group. These results demonstrated that the biomechanical stiffening effect produced by BAC-EDTA transepithelial CXL was greater than that produced by standard epithelium-off CXL in a rabbit model.

  1. Disinfection of water and wastewater by UV-A and UV-C irradiation: application of real-time PCR method.

    PubMed

    Chatzisymeon, Efthalia; Droumpali, Ariadni; Mantzavinos, Dionissios; Venieri, Danae

    2011-03-02

    The disinfection efficiency of synthetic and real wastewater by means of UV-A and UV-C irradiation in the presence or absence of TiO(2) was investigated. A reference strain of Escherichia coli suspended in sterile 0.8% (w/v) NaCl aqueous solution was used as a synthetic wastewater, while real wastewater samples were collected from the outlet of the secondary treatment of a municipal wastewater treatment plant. E. coli inactivation was monitored both by the conventional culture technique and by the real-time PCR method. Culture method showed that UV-C irradiation (11 W lamp) achieved total E. coli inactivation of 100% within 3 min of photolytic treatment. On the other hand, UV-A (9 W lamp)/TiO(2); [TiO(2)]=200 mg L(-1) (i.e. best operating conditions) required 60 min to achieve total disinfection of the synthetic wastewater. Real time PCR revealed compatible results, regarding the better efficiency of UV-C. However, it showed different times of bacterial inactivation, probably due to the phenomenon of "viable but not culturable bacteria". Disinfection durability tests in the dark and under natural sunlight irradiation showed that there is cell repair when UV-C irradiation is used for synthetic wastewater disinfection. Regarding real wastewater it was observed that only UV-C irradiation was capable of totally inactivating E. coli population in short time. Comparing results obtained from both methods, real time PCR proved to be more reliable and accurate, concerning the bacterial detection and enumeration in aquatic samples after the application of UV irradiation.

  2. Characterizing reactive oxygen generation and bacterial inactivation by a zerovalent iron-fullerene nano-composite device at neutral pH under UV-A illumination.

    PubMed

    Erdim, Esra; Badireddy, Appala Raju; Wiesner, Mark R

    2015-01-01

    A nano-composite device composed of nano-scale zerovalent iron (ZVI) and C60 fullerene aggregates (ZVI/nC60) was produced via a rapid nucleation method. The device was conceived to deliver reactive oxygen species (ROS) generated by photosensitization and/or electron transfer to targeted contaminants, including waterborne pathogens under neutral pH conditions. Certain variations of the nano-composite were fabricated differing in the amounts of (1) ZVI (0.1mM and 2mM) but not nC60 (2.5mg-C/L), and (2) nC60 (0-25mg-C/L) but not ZVI (0.1mM). The generation of ROS by the ZVI/nC60 nano-composites and ZVI nanoparticles was quantified using organic probe compounds. 0.1mM ZVI/2.5mg-C/L C60 generated 3.74-fold higher O2(-) concentration and also resulted in an additional 2-log inactivation of Pseudomonas aeruginosa when compared to 0.1mM ZVI (3-log inactivation). 2mM ZVI/2.5mg-C/L nC60 showed negligible improvement over 2mM ZVI in terms of O2(-) generation or inactivation. Further, incremental amounts of nC60 in the range of 0-25mg-C/L in 0.1mM ZVI/nC60 led to increased O2(-) concentration, independent of UV-A. This study demonstrates that ZVI/nC60 device delivers (1) enhanced O2(-) with nC60 as a mediator for electron transfer, and (2) (1)O2 (only under UV-A illumination) at neutral pH conditions.

  3. Influence of the absorption behavior of sunscreens in the short-wavelength UV range (UVB) and the long-wavelength UV range (UVA) on the relation of the UVB absorption to sun protection factor

    NASA Astrophysics Data System (ADS)

    Weigmann, Hans-Juergen; Schanzer, Sabine; Antoniou, Christina; Sterry, Wolfram; Lademann, Juergen

    2010-09-01

    The absorption of filter substances in sunscreens, reducing the incident ultraviolet (UV) radiation, is the basis for the protecting ability of such formulations. The erythema-correlated sun protection factor (SPF), depending mainly on the intensity of the UVB radiation, is the common value to quantify the efficacy of the formulations avoiding sunburn. An ex vivo method combining tape stripping and optical spectroscopy is applied to measure the absorption of sunscreens in the entire UV spectral range. The obtained relations between the short-wavelength UV (UVB) absorption and the SPF confirm a clear influence of the long-wavelength UV (UVA) absorption on the SPF values. The data reflect the historical development of the relation of the concentration of UVB and UVA filters in sunscreens and points to the influence of additional ingredients, e.g., antioxidants and cell-protecting agents on the efficacy of the products.

  4. Influence of the absorption behavior of sunscreens in the short-wavelength UV range (UVB) and the long-wavelength UV range (UVA) on the relation of the UVB absorption to sun protection factor.

    PubMed

    Weigmann, Hans-Juergen; Schanzer, Sabine; Antoniou, Christina; Sterry, Wolfram; Lademann, Juergen

    2010-01-01

    The absorption of filter substances in sunscreens, reducing the incident ultraviolet (UV) radiation, is the basis for the protecting ability of such formulations. The erythema-correlated sun protection factor (SPF), depending mainly on the intensity of the UVB radiation, is the common value to quantify the efficacy of the formulations avoiding sunburn. An ex vivo method combining tape stripping and optical spectroscopy is applied to measure the absorption of sunscreens in the entire UV spectral range. The obtained relations between the short-wavelength UV (UVB) absorption and the SPF confirm a clear influence of the long-wavelength UV (UVA) absorption on the SPF values. The data reflect the historical development of the relation of the concentration of UVB and UVA filters in sunscreens and points to the influence of additional ingredients, e.g., antioxidants and cell-protecting agents on the efficacy of the products.

  5. In vivo activation of human immunodeficiency virus type 1 long terminal repeat by UV type A (UV-A) light plus psoralen and UV-B light in the skin of transgenic mice.

    PubMed Central

    Morrey, J D; Bourn, S M; Bunch, T D; Jackson, M K; Sidwell, R W; Barrows, L R; Daynes, R A; Rosen, C A

    1991-01-01

    UV irradiation has been shown to activate the human immunodeficiency virus type 1 (HIV-1) long terminal repeat (LTR) in cell culture; however, only limited studies have been described in vivo. UV light has been categorized as UV-A (400 to 315 nm), -B (315 to 280 nm), or -C (less than 280 nm); the longer wavelengths are less harmful but more penetrative. Highly penetrative UV-A radiation constitutes the vast majority of UV sunlight reaching the earth's surface but is normally harmless. UV-B irradiation is more harmful but less prevalent than UV-A. In this report, the HIV-1 LTR-luciferase gene in the skin of transgenic mice was markedly activated when exposed to UV-B irradiation. The LTR in the skin of transgenic mice pretreated topically with a photosensitizing agent (psoralen) was also activated to similar levels when exposed to UV-A light. A 2-h exposure to sunlight activated the LTR in skin treated with psoralen, whereas the LTR in skin not treated with psoralen was activated after 7 h of sunlight exposure. The HIV-1 LTR-beta-galactosidase reporter gene was preferentially activated by UV-B irradiation in a small population of epidermal cells. The transgenic mouse models carrying HIV-1 LTR-luciferase and LTR-beta-galactosidase reporter genes have been used to demonstrate the in vivo UV-induced activation of the LTR and might be used to evaluate other environmental factors or pharmacologic substances that might potentially activate the HIV-1 LTR in vivo. Images PMID:1908029

  6. NASA-UVA Light Aerospace Alloy and Structures Technology Program (LA2ST). Supplement: Research on Materials for the High Speed Civil Transport

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.; Starke, Edgar A., Jr.

    1997-01-01

    This report documents the progress achieved over the past 6 to 12 months on four graduate student projects conducted within the NASA-UVA Light Aerospace Alloy and Structures Technology Program. These studies were aimed specifically at light metallic alloy issues relevant to the High Speed Civil Transport. Research on Hydrogen-Enhanced Fracture of High-Strength Titanium Alloy Sheet refined successfully the high resolution R-curve method necessary to characterize initiation and growth fracture toughnesses. For solution treated and aged Low Cost Beta without hydrogen precharging, fracture is by ductile transgranular processes at 25 C, but standardized initiation toughnesses are somewhat low and crack extension is resolved at still lower K-levels. This fracture resistance is degraded substantially, by between 700 and 1000 wppm of dissolved hydrogen, and a fracture mode change is affected. The surface oxide on P-titanium alloys hinders hydrogen uptake and complicates the electrochemical introduction of low hydrogen concentrations that are critical to applications of these alloys. Ti-15-3 sheet was obtained for study during the next reporting period. Research on Mechanisms of deformation and Fracture in High-Strength Titanium Alloys is examining the microstructure and fatigue resistance of very thin sheet. Aging experiments on 0. 14 mm thick (0.0055 inch) foil show microstructural agility that may be used to enhance fatigue performance. Fatigue testing of Ti-15-3 sheet has begun. The effects of various thermo-mechanical processing regimens on mechanical properties will be examined and deformation modes identified. Research on the Effect of Texture and Precipitates on Mechanical Property Anisotropy of Al-Cu-Mg-X and Al-Cu alloys demonstrated that models predict a minor influence of stress-induced alignment of Phi, caused by the application of a tensile stress during aging, on the yield stress anisotropy of both modified AA2519 and a model Al-Cu binary alloy. This project

  7. Technology and mechanism of neuron inactivation by N2 laser radiation (λ=337 nm), mercury-vapor lamp (Hg λ=365 nm), and low-coherence UV-A sun radiation

    NASA Astrophysics Data System (ADS)

    Akchurin, Garif G.; Akchurin, George G.; Seliverstov, George A.; Trofimov, Artyom Y.

    2005-04-01

    The method of the local functional injury of somatic frog's nerve using high coherent UV-A radiation of N2 laser (λ=337nm, P~10 mW), coherent mercury-vapor lamp radiation (λ=365 312 nm PΣ~2 mW/cm2) and low-coherence UV-A sun radiation (400-315 nm, PΣ~10 mW) was realized. The level of injury was assessed from the decrease of compound action potential of the nerve stimulated extracellularly by electrical pulses of millisecond duration. Study of dynamic response of the bundle of axons revealed the decrease of the number of action potential which can be generated (less than 105). This decrease may be attributed to destruction of action transport and/or voltage-activated ion channels of axon membrane. The dose dependence of the level of nerve injury was studied using varied both intensity and duration of high and low-coherent UV-A irradiation.

  8. Effect of the product type, of the amount of applied sunscreen product and the level of protection in the UVB range on the level of protection achieved in the UVA range.

    PubMed

    Couteau, C; Diarra, H; Coiffard, L

    2016-03-16

    Using a topical product is part of the overall strategy for skin cancer prevention. The level of protection attainable when using commercial products is indicated by the Sun Protection Factor (SPF) value, in use everywhere. This value reflects the level of protection primarily in the UVB range. However, UVA radiation also has deleterious effects on the skin, and it is essential to prevent it, which is why products must offer a wide spectrum of protection. Tests conducted in vivo, before any marketing, are done by applying the studied product at a rate of 2.0 mg cm(-2), while users, in practice, only use 1.0-1.5 mg cm(-2). We now know that this reduction in the amount of applied product greatly affects the SPF. To complete the state of knowledge in this area, we sought to evaluate the effect of a decrease in the amount of applied sunscreen product by studying sunscreen creams and oils on the level of protection attainable in the UVA range. We have shown that the PF-UVA is divided by a factor of 2.2, on average, when the amount of applied product is reduced by half, with differences depending on the product type under consideration (cream or oil) and depending on the SPF of the preparation.

  9. Redox Mechanisms of AVS022, an Oriental Polyherbal Formula, and Its Component Herbs in Protection against Induction of Matrix Metalloproteinase-1 in UVA-Irradiated Keratinocyte HaCaT Cells

    PubMed Central

    Pluemsamran, Thanyawan; Tripatara, Pinpat; Phadungrakwittaya, Rattana; Akarasereenont, Pravit; Laohapand, Tawee

    2013-01-01

    Ayurved Siriraj HaRak (AVS022) formula has been used for topical remedy of dermatologic disorders. Oxidative stress induced by ultraviolet (UV) A irradiation could be implicated in photoaged skin through triggering matrix metalloproteinase-1 (MMP-1). We, therefore, explored the antioxidant mechanisms by which AVS022 formulation and its individual components protected against UVA-dependent MMP-1 upregulation in keratinocyte HaCaT cells. TLC analysis revealed the presence of multiple phenolics including gallic acid (GA) in the AVS022 extracts. We demonstrated that pretreatment with the whole formula and individual herbal components except T. triandra protected against increased MMP-1 activity in irradiated HaCaT cells. Moreover, all herbal extracts and GA, used as the reference compound, were able to reverse cytotoxicity, oxidant production, glutathione (GSH) loss, and inactivation of catalase and glutathione peroxidase (GPx). F. racemosa was observed to yield the strongest abilities to abolish UVA-mediated induction of MMP-1 and impairment of antioxidant defenses including GSH and catalase. Our observations suggest that upregulation of endogenous antioxidants could be the mechanisms by which AVS022 and its herbal components suppressed UVA-stimulated MMP-1 in HaCaT cells. In addition, pharmacological actions of AVS022 formula may be attributed to the antioxidant potential of its components, in particular F. racemosa, and several phenolics including GA. PMID:24171043

  10. Zinc l-pyrrolidone carboxylate inhibits the UVA-induced production of matrix metalloproteinase-1 by in vitro cultured skin fibroblasts, whereas it enhances their collagen synthesis.

    PubMed

    Takino, Y; Okura, F; Kitazawa, M; Iwasaki, K; Tagami, H

    2012-02-01

    Reduced collagen matrix in the dermis constitutes one of the characteristic features of chronologically aged skin, which is further enhanced on the sun-exposed portions of the body by chronic ultraviolet light (UV) irradiation, inducing the unique changes associated with skin photoageing. The zinc salt of l-pyrrolidone carboxylate (Zinc PCA) has long been used as a cosmetic ingredient, because of its astringent and anti-microbial properties. In the present study, by employing cultured normal human dermal fibroblasts, we found that Zinc PCA suppressed UVA-induced activation of activator protein-1 (AP-1) and reduced matrix metalloproteinase-1 production in these cells, which is thought to be involved in collagen degradation in photoaged skin. Moreover, Zinc PCA treatment of the cells increased the expression of an ascorbic acid transporter mRNA, SVCT2, but not SVCT1, resulting in the enhanced production of type I collagen. Based on these in vitro findings, we consider Zinc PCA to be a promising candidate for an anti-skin ageing agent.

  11. Decomposition of sulfamethoxazole and trimethoprim by continuous UVA/LED/TiO2 photocatalysis: Decomposition pathways, residual antibacterial activity and toxicity.

    PubMed

    Cai, Qinqing; Hu, Jiangyong

    2017-02-05

    In this study, continuous LED/UVA/TiO2 photocatalytic decomposition of sulfamethoxazole (SMX) and trimethoprim (TMP) was investigated. More than 90% of SMX and TMP were removed within 20min by the continuous photoreactor (with the initial concentration of 400ppb for each). The removal rates of SMX and TMP decreased with higher initial antibiotics loadings. SMX was much easier decomposed in acidic condition, while pH affected little on TMP's decomposition. 0.003% was found to be the optimum H2O2 dosage to enhance SMX photocatalytic decomposition. Decomposition pathways of SMX and TMP were proposed based on the intermediates identified by using LC-MS-MS and GC-MS. Aniline was identified as a new intermediate generated during SMX photocatalytic decomposition. Antibacterial activity study with a reference Escherichia coli strain was also conducted during the photocatalytic process. Results indicated that with every portion of TMP removed, the residual antibacterial activity decreased by one portion. However, the synergistic effect between SMX and TMP tended to slow down the antibacterial activity removal of SMX and TMP mixture. Chronic toxicity studies conducted with Vibrio fischeri exhibited 13-20% bioluminescence inhibition during the decomposition of 1ppm SMX and 1ppm TMP, no acute toxicity to V. fischeri was observed during the photocatalytic process.

  12. Requirements of blue, UV-A, and UV-B light for normal growth of higher plants, as assessed by action spectra for growth and related phenomena

    NASA Technical Reports Server (NTRS)

    Hashimoto, T.

    1994-01-01

    Artificial lighting is very important for experimental purposes, as well as for the practical use of plants when not enough sunlight is available. To grow green higher plants in their normal forms under artificial lighting constructing efficient and economically reasonable lighting systems is not an easy task. One possible approach would be to simulate sunlight in intensity and the radiation spectrum, but its high construction and running costs are not likely to allow its use in practice. Sunlight may be excessive in irradiance in some or all portions of the spectrum. Reducing irradiance and removing unnecessary wavebands might lead to an economically feasible light source. However, removing or reducing a particular waveband from sunlight for testing is not easy. Another approach might be to find the wavebands required for respective aspects of plant growth and to combine them in a proper ratio and intensity. The latter approach seems more practical and economical, and the aim of this Workshop lies in advancing this approach. I summarize our present knowledge on the waveband requirements of higher plants for the regions of blue, UV-A and UV-B.

  13. UV-A light-induced photodegradation of Acid Blue 113 in the presence of Sm-doped ZnO nanostructures

    NASA Astrophysics Data System (ADS)

    Pandiyarajan, Thangaraj; Mangalaraja, Ramalinga Viswanathan; Karthikeyan, Balasubramanian; Sathishkumar, Panneerselvam; Mansilla, Héctor D.; Contreras, David; Ruiz, José

    2015-05-01

    In this report, optical and photocatalytic degradation of Acid Blue 113 (AB 113) has been investigated in an aqueous heterogeneous media containing pure and Sm-doped ZnO nanostructures which were prepared by a simple wet chemical route. X-ray diffraction measurement confirmed that the prepared nanostructures were in hexagonal wurtzite structure and the dopant Sm ion was incorporated into the Zn lattice. Interesting morphological changes involving a nanosheet-star-spherical transition were observed upon Sm doping and annealing, which were identified through transmission electron microscope. Optical absorption measurements showed an exciton absorption band and a band gap narrowing with respect to the Sm concentrations. The photodegradation of Acid Blue 113 under UV-A radiation by using pure and Sm-doped ZnO nanostructures showed that samarium played an important role in the significant improvement of the photodegradation efficiency and the optimum amount of Sm ion was found to be 1 mmol %. Further, the possible degradation mechanism was proposed herein.

  14. Photocatalytic degradation of an azo dye Sunset Yellow under UV-A light using TiO2/CAC composite catalysts

    NASA Astrophysics Data System (ADS)

    Rajamanickam, D.; Shanthi, M.

    2014-07-01

    The photocatalytic activity and the promoting effect of titania (TiO2) by commercial activated carbon (CAC) for removing the pollutant in wastewater were investigated. The TiO2/CAC composite photocatalysts with various ratios of CAC to TiO2 were prepared by sol-gel method. The catalyst was characterized by X-ray diffraction (XRD), high resolution scanning electron microscope (HR-SEM), energy dispersive spectra (EDS), diffuse reflectance spectra (DRS), photoluminescence spectra (PL), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) surface area measurement methods. The photocatalytic activity of TiO2/CAC was investigated for the degradation of Sunset Yellow (SY) in aqueous solution using UV-A light. The TiO2/CAC is found to be more efficient than prepared TiO2 and TiO2-P25 at pH 7 for the mineralization of SY. The synergism between TiO2 and CAC may increase the catalytic activity. The effects of operational parameters such as the amount of photocatalyst, dye concentration and initial pH on photo mineralization of SY have been analyzed. The mineralization of SY has been confirmed by COD measurements. The catalyst is found to be reusable.

  15. Photocatalytic degradation of an azo dye Sunset Yellow under UV-A light using TiO2/CAC composite catalysts.

    PubMed

    Rajamanickam, D; Shanthi, M

    2014-07-15

    The photocatalytic activity and the promoting effect of titania (TiO2) by commercial activated carbon (CAC) for removing the pollutant in wastewater were investigated. The TiO2/CAC composite photocatalysts with various ratios of CAC to TiO2 were prepared by sol-gel method. The catalyst was characterized by X-ray diffraction (XRD), high resolution scanning electron microscope (HR-SEM), energy dispersive spectra (EDS), diffuse reflectance spectra (DRS), photoluminescence spectra (PL), X-ray photoelectron spectroscopy (XPS) and Brunauer-Emmett-Teller (BET) surface area measurement methods. The photocatalytic activity of TiO2/CAC was investigated for the degradation of Sunset Yellow (SY) in aqueous solution using UV-A light. The TiO2/CAC is found to be more efficient than prepared TiO2 and TiO2-P25 at pH 7 for the mineralization of SY. The synergism between TiO2 and CAC may increase the catalytic activity. The effects of operational parameters such as the amount of photocatalyst, dye concentration and initial pH on photo mineralization of SY have been analyzed. The mineralization of SY has been confirmed by COD measurements. The catalyst is found to be reusable.

  16. An in vitro systematic spectroscopic examination of the photostabilities of a random set of commercial sunscreen lotions and their chemical UVB/UVA active agents.

    PubMed

    Serpone, Nick; Salinaro, Angela; Emeline, Alexei V; Horikoshi, Satoshi; Hidaka, Hisao; Zhao, Jincai

    2002-12-01

    The photostabilities of a random set of commercially available sunscreen lotions and their active ingredients are examined spectroscopically subsequent to simulated sunlight UV exposure. Loss of filtering efficacy can occur because of possible photochemical modifications of the sunscreen active agents. Changes in absorption of UVA/ UVB sunlight by agents in sunscreen lotions also leads to a reduction of the expected photoprotection of human skin and DNA against the harmful UV radiation. The active ingredients were investigated in aqueous media and in organic solvents of various polarities (methanol, acetonitrile, and n-hexane) under aerobic and anaerobic conditions The UV absorption features are affected by the nature of the solvents with properties closely related to oil-in-water (o/w) or water-in-oil (w/o) emulsions actually used in sunscreen formulations, and by the presence of molecular oxygen. The photostabilities of two combined chemical ingredients (oxybenzone and octyl methoxycinnamate) and the combination oxybenzone/titanium dioxide were also explored. In the latter case, oxybenzone undergoes significant photodegradation in the presence of the physical filter TiO2.

  17. Action spectrum analysis of UVR genotoxicity for skin: the border wavelengths between UVA and UVB can bring serious mutation loads to skin.

    PubMed

    Ikehata, Hironobu; Higashi, Shoichi; Nakamura, Shingo; Daigaku, Yasukazu; Furusawa, Yoshiya; Kamei, Yasuhiro; Watanabe, Masakatsu; Yamamoto, Kazuo; Hieda, Kotaro; Munakata, Nobuo; Ono, Tetsuya

    2013-07-01

    UVR causes erythema, which has been used as a standardized index to evaluate the risk of UVR for human skin. However, the genotoxic significance of erythema has not been elucidated clearly. Here, we characterized the wavelength dependence of the genotoxic and erythematic effects of UVR for the skin by analyzing the induction kinetics of mutation and inflammation in mouse skin using lacZ-transgenic mice and monochromatic UVR sources. We determined their action spectra and found a close correlation between erythema and an epidermis-specific antigenotoxic response, mutation induction suppression (MIS), which suppressed the mutant frequencies (MFs) to a constant plateau level only 2-3-fold higher than the background MF at the cost of apoptotic cell death, suggesting that erythema may represent the threshold beyond which the antigenotoxic but tissue-destructive MIS response commences. However, we unexpectedly found that MIS attenuates remarkably at the border wavelengths between UVA and UVB around 315 nm, elevating the MF plateaus up to levels ∼40-fold higher than the background level. Thus, these border wavelengths can bring heavier mutation loads to the skin than the otherwise more mutagenic and erythematic shorter wavelengths, suggesting that erythema-based UVR risk evaluation should be reconsidered.

  18. Broad-spectrum antimicrobial photocatalysis mediated by titanium dioxide and UVA is potentiated by addition of bromide ion via formation of hypobromite.

    PubMed

    Wu, Ximing; Huang, Ying-Ying; Kushida, Yu; Bhayana, Brijesh; Hamblin, Michael R

    2016-06-01

    Antimicrobial photocatalysis involves the UVA excitation of titanium dioxide (TiO2) nanoparticles (particularly the anatase form) to produce reactive oxygen species (ROS) that kill microbial cells. For the first time we report that the addition of sodium bromide to photoactivated TiO2 (P25) potentiates the killing of Gram-positive, Gram-negative bacteria and fungi by up to three logs. The potentiation increased with increasing bromide concentration in the range of 0-10mM. The mechanism of potentiation is probably due to generation of both short and long-lived oxidized bromine species including hypobromite as shown by the following observations. There is some antimicrobial activity remaining in solution after switching off the light, that lasts for 30min but not 2h, and oxidizes 3,3',5,5'-tetramethylbenzidine. N-acetyl tyrosine ethyl ester was brominated in a light dose-dependent manner, however no bromine or tribromide ion could be detected by spectrophotometry or LC-MS. The mechanism appears to have elements in common with the antimicrobial system (myeloperoxidase+hydrogen peroxide+bromide).

  19. Treatment of a mixture of food color additives (E122, E124 and E129) in different water matrices by UVA and solar photoelectro-Fenton.

    PubMed

    Thiam, Abdoulaye; Sirés, Ignasi; Brillas, Enric

    2015-09-15

    The degradation of 130 mL of mixtures of food azo dyes E122, E124 and E129 has been studied by electro-Fenton (EF) and UVA photoelectro-Fenton (PEF) using a stirred tank reactor with either a boron-doped diamond (BDD) or Pt anode and an air-diffusion cathode. The main oxidant was hydroxyl radical formed at the anode from water oxidation and in the bulk from Fenton's reaction between added Fe(2+) and H2O2 generated at the cathode. In sulfate medium, fast decolorization was found for all systems, but the almost total mineralization was more rapidly achieved by PEF with BDD. The performance with a real water matrix was slightly worse, although the removal of total organic load was still as high as 95%. The solar PEF (i.e., SPEF) treatment of dye mixtures using a 2.5 L flow plant with a BDD/air-diffusion cell coupled to a planar solar photoreactor is also reported. Fast decolorization and almost total mineralization was found in the presence of either sulfate, perchlorate, nitrate or a mixture of sulfate + chloride ions. In chloride medium, however, the formation of recalcitrant chloroderivatives decelerated the degradation process. Greater current efficiency and lower specific energy consumption were attained in sulfate medium at lower current density and higher azo dye content. A plausible reaction sequence based on 18 aromatic intermediates identified by GC-MS and 6 short-linear carboxylic acids detected by ion-exclusion HPLC has been proposed. The SPEF process promoted the photodegradation of Fe(III)-oxalate complexes and other undetected products. Sulfate and nitrate ions were always released to the medium.

  20. A prospective, active haemovigilance study with combined cohort analysis of 19 175 transfusions of platelet components prepared with amotosalen–UVA photochemical treatment

    PubMed Central

    Knutson, F; Osselaer, J; Pierelli, L; Lozano, M; Cid, J; Tardivel, R; Garraud, O; Hervig, T; Domanovic, D; Cukjati, M; Gudmundson, S; Hjalmarsdottir, I B; Castrillo, A; Gonzalez, R; Brihante, D; Santos, M; Schlenke, P; Elliott, A; Lin, J-S; Tappe, D; Stassinopoulos, A; Green, J; Corash, L

    2015-01-01

    Background and Objectives A photochemical treatment process (PCT) utilizing amotosalen and UVA light (INTERCEPT™ Blood System) has been developed for inactivation of viruses, bacteria, parasites and leucocytes that can contaminate blood components intended for transfusion. The objective of this study was to further characterize the safety profile of INTERCEPT-treated platelet components (PCT-PLT) administered across a broad patient population. Materials and Methods This open-label, observational haemovigilance programme of PCT-PLT transfusions was conducted in 21 centres in 11 countries. All transfusions were monitored for adverse events within 24 h post-transfusion and for serious adverse events (SAEs) up to 7 days post-transfusion. All adverse events were assessed for severity (Grade 0–4), and causal relationship to PCT-PLT transfusion. Results Over the course of 7 years in the study centres, 4067 patients received 19 175 PCT-PLT transfusions. Adverse events were infrequent, and most were of Grade 1 severity. On a per-transfusion basis, 123 (0·6%) were classified an acute transfusion reaction (ATR) defined as an adverse event related to the transfusion. Among these ATRs, the most common were chills (77, 0·4%) and urticaria (41, 0·2%). Fourteen SAEs were reported, of which 2 were attributed to platelet transfusion (<0·1%). No case of transfusion-related acute lung injury, transfusion-associated graft-versus-host disease, transfusion-transmitted infection or death was attributed to the transfusion of PCT-PLT. Conclusion This longitudinal haemovigilance safety programme to monitor PCT-PLT transfusions demonstrated a low rate of ATRs, and a safety profile consistent with that previously reported for conventional platelet components. PMID:25981525

  1. Title VII Enhancement Project for Compartiendo Culturas/Sharing Cultures 1995-96. Research Report on Educational Programs.

    ERIC Educational Resources Information Center

    Houston Independent School District, TX. Dept. of Research and Evaluation.

    Compartiendo Culturas/Sharing Cultures, a Title VII Two-Way Developmental Bilingual Education Program at the Gary L. Herod Elementary School in the Houston Independent School District (Texas) was designed to end the isolation typically experienced by language minority students in traditional bilingual education and to provide language majority…

  2. Activity Report: "Escola de Cultura de Pau", the Laureate of the First Evens Prize for Peace Education

    ERIC Educational Resources Information Center

    Delvou, Marjolein

    2011-01-01

    On March 18th 2011 an independent jury of experts convened in Antwerp, Belgium, to select the laureate of the first Evens Prize for Peace Education from a shortlist of eleven organizations from all over Europe. After a long day of intense discussions, the jury agreed unanimously to award the prize to the "Escola de Cultura de Pau"…

  3. Photopheresis with UV-A light and 8-methoxypsoralen leads to cell death and to release of blebs with anti-inflammatory phenotype in activated and non-activated lymphocytes

    SciTech Connect

    Stadler, K.; Frey, B.; Munoz, L.E.; Finzel, S.; Rech, J.; Fietkau, R.; Herrmann, M.; Hueber, A.; Gaipl, U.S.

    2009-08-14

    Background: Extracorporeal photopheresis is a therapy for treatment of autoimmune diseases, cutaneous T-cell lymphoma, organ graft rejection as well as graft-versus-host diseases. The exact mechanism how the combination of 8-methoxypsoralen plus UV-A irradiation (PUVA) acts is still unclear. We investigated the cell death of activated and non-activated lymphocytes after PUVA treatment as well as the rate of released blebs and their antigen composition. Results: In presence of 8-MOP, UV-A light highly significantly increased the cell death of activated lymphocytes. The same was observed to a lesser extent in non-activated cells. Blebs derived from activated lymphocytes after PUVA treatment showed the highest surface exposition of phosphatidylserine. These blebs also displayed a high exposure of the antigens CD5 and CD8 as well as a low exposure of CD28 and CD86. Conclusion: PUVA treatment exerts anti-inflammatory effects by inducing apoptosis and apoptotic cell-derived blebs with immune suppressive surface composition.

  4. Different Cultures in Astronomy Education and Their Meanings in the Classroom. (Spanish Title: Las Diferentes Culturas en la Educación en Astronomía y Sus Significados EN EL Aula. ) As Diferentes Culturas na Educação em Astronomia E Seus Significados em Sala de Aula

    NASA Astrophysics Data System (ADS)

    Pereira de Barros, Vicente; Bovolenta Ovigli, Daniel Fernando

    2014-12-01

    el trabajo con Astronomía(s) en la clase. Se observó que los participantes todavía no habían presentado estos temas en sus clases y tampoco habían participado en cursos de formación que abordaran estos temas. O presente trabalho apresenta uma reflexão acerca da utilização da História da Ciência no currículo da educação formal, por meio da discussão relativa ao emprego de elementos culturais de grupos étnicos em ações voltadas à educação em Astronomia. O trabalho foi desenvolvido no âmbito de um curso de extensão e a análise aqui empreendida refere-se a um encontro que abordou sequências didáticas relativas àquele tema, com fundamento na lei 11.645/2008 e a obrigatoriedade de abordagem da temática "História e Cultura Afro-Brasileira e Indígena" no currículo oficial. A ação de extensão ocorreu junto a professores que ensinam Ciências da Natureza, no interior do estado de São Paulo, discutindo-se temas relativos ao uso de História da Ciência e o relacionamento com cosmogonias oriundas dos povos Iorubá e Tupi, evidenciando como podem enriquecer o trabalho com a(s) Astronomia(s) em sala de aula. Observou-se que os participantes ainda não haviam apresentado estes temas em suas aulas e, igualmente, não participaram de cursos de formação que contemplassem a referida temática.

  5. Ministerio da Educacao e Cultura. Trinta Anos de Organizacao e Situacao Atual (Ministry of Education and Culture [Brazil]. Thirty Years Ago and Now). Volumes I and III.

    ERIC Educational Resources Information Center

    Porto, Norma Carneiro Monteiro

    The economic rather than the educational aspect of Brazil's Ministry of Education and Culture is presented in this historical summary. The study was done as part of Brazil's national program of educational reform. Brazil is currently re-evaluating its school system with the view of adopting a nationally-administered system similar to that in…

  6. Evaluating the toxicity/fixation balance for corneal cross-linking with sodium hydroxymethylglycinate (SMG) and riboflavin-UVA (CXL) in an ex vivo rabbit model using confocal laser scanning fluorescence microscopy

    PubMed Central

    Kim, Su-Young; Babar, Natasha; Takaoka, Anna; Zyablitskaya, Mariya; Nagasaki, Takayuki; Trokel, Stephen L.; Paik, David C.

    2015-01-01

    Purpose To develop methods to delineate the relationship between endothelial cell toxicity and tissue fixation (toxicity/fixation) using sodium hydroxymethylglycinate (SMG), a formaldehyde releaser, and riboflavin-UVA (CXL) for therapeutic tissue cross-linking of the cornea. Methods Eleven (11) fresh cadaveric rabbit heads were used for ex vivo corneal cross-linking simulation. Following epithelial debridement, the tissue was exposed to 1/4 Max (9.765mM) or 1/3Max (13.02mM) SMG at pH 8.5 for 30min or riboflavin-UVA (CXL). The contralateral cornea served as a paired control. Post-exposure, cross-linking efficacy was determined by thermal denaturation temperature (Tm) and endothelial damage was assessed using calcein AM and ethidium homodimer staining (Live/Dead Kit). Confocal laser scanning fluorescence microscopy was used to generate live/dead cell counts following a standardized algorithm. Results The ΔTm following CXL, 1/3 SMG, and 1/4 SMG was 2.19±0.91°C, 1.33±0.49 °C, and 1.10 ±0.46 °C, respectively. Endothelial cell damage was expressed as the percent of dead cells/live + dead cells counted per high powered field. The values were 2.95±1.74% (control) and 8.86±11.10% (CXL) [p=0.390]; 0.98±0.20% (control) and 19.53±32.22% (1/3max SMG) [p=0.426]; and 2.70±2.37% (control) and 2.84±2.24% (1/4 max SMG) [p=0.938];. The values for endothelial toxicity were then indexed over the shift in Tm in order to yield a toxicity/fixation index. The values were as follows: 2.70 for CXL, 13.95 for 1/3 max, and 0.13 for 1/4 max. Conclusions Quarter max (1/4 Max = 9.765mM) SMG effectively cross-linked tissue and was non-toxic to endothelial cells. Thus, SMG is potentially a compound that could achieve both desired effects. PMID:26807905

  7. UVA light stimulates the production of cathepsin G and elastase-like enzymes by dermal fibroblasts: a possible contribution to the remodeling of elastotic areas in sun-damaged skin.

    PubMed

    Cavarra, Eleonora; Fimiani, Michele; Lungarella, Giuseppe; Andreassi, Lucio; de Santi, Margherita; Mazzatenta, Carlo; Ciccoli, Lucia

    2002-01-01

    Solar elastosis is characterized by accumulation of large amounts of material staining similarly to elastin in the dermis. The nature of this material and the process responsible for its accumulation are still unknown. Elastolytic proteases have important functions in the catabolism of the interstitial matrix and can also generate, by the digestion of the interstitial proteins, soluble peptides which can induce collagen and elastin synthesis and deposition. We investigated whether (i) elastolytic enzymes can be detected in samples from sun-exposed and non-exposed skin, and (ii) ultraviolet (UV) rays influence the production of elastolytic activities in cultured dermal fibroblasts. Immunoelectron microscopy showed a positive reaction for neutrophil elastase and cathepsin G in fibroblast-like cells from specimens of sun-exposed areas. Little or no reaction was found in biopsies of sun-protected skin. Fibroblast cultures from sun-exposed skin expressed higher levels of hydrolytic activity against synthetic substrates of elastases and cathepsin G than those obtained from sun-protected areas. Irradiation with UVA strongly stimulated the production of these activities in fibroblasts from sun-protected sites. No significant change was detected in parallel sets of cultures after UVB irradiation. Inhibition experiments indicated that the elastase-like activity expressed by fibroblasts can be attributed to at least two enzymes.

  8. Henrique da Rocha Lima.

    PubMed

    Bernardes Filho, Fred; Avelleira, João Carlos Regazzi

    2015-01-01

    Brazilian physician and researcher Henrique da Rocha Lima was born in 1879 in the city of Rio de Janeiro, where he studied medicine and obtained the degree of M.D. in 1901. He specialized in Clinical Medicine in Germany and was the ambassador in European countries of the scientific medicine that emerged from the Oswaldo Cruz Institute in the early twentieth century. Rocha Lima has discovered the causative agent of typhus and had a major contribution to the studies of yellow fever, Chagas disease, Carrión's disease and histoplasmosis. His genius, his research and his discoveries projected his name, and, with it, the image of Brazil in the international scientific scene.

  9. Berengario da Carpi.

    PubMed

    De Santo, N G; Bisaccia, C; De Santo, L S; De Santo, R M; Di Leo, V A; Papalia, T; Cirillo, M; Touwaide, A

    1999-01-01

    Berengario da Carpi was magister of anatomy and surgery at the University of Bologna from 1502 to 1527. Eustachio and Falloppia defined him as 'the restaurator of anatomy'. He was a great surgeon, anatomist and physician of illustrious patients including Lorenzo II dei Medici, Giovanni dalle Bande Nere, Galeazzo Pallavicini, Cardinal Colonna, and Alessandro Soderini. He had strong links to the intellectuals of his time (Forni, Bonamici, Manuzio, Pomponazzi) as well as with the Medici family. He was respected by the Popes Julius II, Leo X and Clement VII. His main contributions are the Isogogae Breves, De Fractura calvae sive cranei, and the illustrated Commentaria on the Anatomy of Mondino de Liucci, a textbook utilized for more than 200 years, which Berengario aimed to restore to its initial text. The Commentaria constitutes the material for the last part of this paper which concludes with a personal translation of some passages on 'The kidney', where the author gives poignant examples of experimental ingenuity.

  10. Henrique da Rocha Lima*

    PubMed Central

    Bernardes Filho, Fred; Avelleira, João Carlos Regazzi

    2015-01-01

    Brazilian physician and researcher Henrique da Rocha Lima was born in 1879 in the city of Rio de Janeiro, where he studied medicine and obtained the degree of M.D. in 1901. He specialized in Clinical Medicine in Germany and was the ambassador in European countries of the scientific medicine that emerged from the Oswaldo Cruz Institute in the early twentieth century. Rocha Lima has discovered the causative agent of typhus and had a major contribution to the studies of yellow fever, Chagas disease, Carrión’s disease and histoplasmosis. His genius, his research and his discoveries projected his name, and, with it, the image of Brazil in the international scientific scene. PMID:26131867

  11. Identification of protein phosphatase interacting proteins from normal and UVA-irradiated HaCaT cell lysates by surface plasmon resonance based binding technique using biotin-microcystin-LR as phosphatase capturing molecule.

    PubMed

    Bécsi, Bálint; Dedinszki, Dóra; Gyémánt, Gyöngyi; Máthé, Csaba; Vasas, Gábor; Lontay, Beáta; Erdődi, Ferenc

    2014-09-05

    Identification of the interacting proteins of protein phosphatases is crucial to understand the cellular roles of these enzymes. Microcystin-LR (MC-LR), a potent inhibitor of protein phosphatase-1 (PP1), -2A (PP2A), PP4, PP5 and PP6, was biotinylated, immobilized to streptavidin-coupled sensorchip surface and used in surface plasmon resonance (SPR) based binding experiments to isolate phosphatase binding proteins. Biotin-MC-LR captured PP1 catalytic subunit (PP1c) stably and the biotin-MC-LR-PP1c complex was able to further interact with the regulatory subunit (MYPT1) of myosin phosphatase. Increased biotin-MC-LR coated sensorchip surface in the Surface Prep unit of Biacore 3000 captured PP1c, PP2Ac and their regulatory proteins including MYPT1, MYPT family TIMAP, inhibitor-2 as well as PP2A-A and -Bα-subunits from normal and UVA-irradiated HaCaT cell lysates as revealed by dot blot analysis of the recovered proteins. Biotin-MC-LR was used for the subcellular localization of protein phosphatases in HaCaT cells by identification of phosphatase-bound biotin-MC-LR with fluorescent streptavidin conjugates. Partial colocalization of the biotin-MC-LR signals with those obtained using anti-PP1c and anti-PP2Ac antibodies was apparent as judged by confocal microscopy. Our results imply that biotin-MC-LR is a suitable capture molecule in SPR for isolation of protein phosphatase interacting proteins from cell lysates in sufficient amounts for immunological detection.

  12. Differential survival of Escherichia coli uvrA, uvrB, and uvrC mutants to psoralen plus UV-A (PUVA): Evidence for uncoupled action of nucleotide excision repair to process DNA adducts.

    PubMed

    Lage, Claudia; Gonçalves, Silvia R F; Souza, Luciana L; de Pádula, Marcelo; Leitão, Alvaro C

    2010-01-21

    The nucleotide excision repair mechanism (NER) of Escherichia coli is responsible for the recognition and elimination of more than twenty different DNA lesions. Herein, we evaluated the in vivo role of NER in the repair of DNA adducts generated by psoralens (mono- or bi-functional) and UV-A light (PUVA) in E. coli. Cultures of wild-type E. coli K12 and mutants for uvrA, uvrB, uvrC or uvrAC genes were treated with PUVA and cell survival was determined. In parallel, kinetics of DNA repair was also evaluated by the comparison of DNA sedimentation profiles in all the strains after PUVA treatment. The uvrB mutant was more sensitive to PUVA treatment than all the other uvr mutant strains. Wild-type strain, and uvrA and uvrC mutants were able to repair PUVA-induced lesions, as seen by DNA sedimentation profiles, while the uvrB mutant was unable to repair the lesions. In addition, a quadruple fpg nth xth nfo mutant was unable to nick PUVA-treated DNA when the crude cell-free extract was used to perform plasmid nicking. These data suggest that DNA repair of PUVA-induced lesions may require base excision repair functions, despite proficient UvrABC activity. These results point to a specific role for UvrB protein in the repair of psoralen adducts, which appear to be independent of UvrA or UvrC proteins, as described for the classical UvrABC endonuclease mechanism.

  13. Transport and concentration controls for chloride, strontium, potassium and lead in Uvas Creek, a small cobble-bed stream in Santa Clara County, California, U.S.A. 2. Mathematical modeling

    USGS Publications Warehouse

    Jackman, A.P.; Walters, R.A.; Kennedy, V.C.

    1984-01-01

    Three models describing solute transport of conservative ion species and another describing transport of species which adsorb linearly and reversibly on bed sediments are developed and tested. The conservative models are based on three different conceptual models of the transient storage of solute in the bed. One model assumes the bed to be a well-mixed zone with flux of solute into the bed proportional to the difference between stream concentration and bed concentration. The second model assumes solute in the bed is transported by a vertical diffusion process described by Fick's law. The third model assumes that convection occurs in a selected portion of the bed while the mechanism of the first model functions everywhere. The model for adsorbing species assumes that the bed consists of particles of uniform size with the rate of uptake controlled by an intraparticle diffusion process. All models are tested using data collected before, during and after a 24-hr. pulse injection of chloride, strontium, potassium and lead ions into Uvas Creek near Morgan Hill, California, U.S.A. All three conservative models accurately predict chloride ion concentrations in the stream. The model employing the diffusion mechanism for bed transport predicts better than the others. The adsorption model predicts both strontium and potassium ion concentrations well during the injection of the pulse but somewhat overestimates the observed concentrations after the injection ceases. The overestimation may be due to the convection of solute deep into the bed where it is retained longer than the 3-week post-injection observation period. The model, when calibrated for strontium, predicts potassium equally well when the adsorption equilibrium constant for strontium is replaced by that for potassium. ?? 1984.

  14. Leonardo da Vinci and the Downburst.

    NASA Astrophysics Data System (ADS)

    Gedzelman, Stanley David

    1990-05-01

    Evidence from the drawings, experiments, and writings of Leonardo da Vinci are presented to demonstrate that da Vinci recognized and, possibly, discovered the downburst and understood its associated airflow. Other early references to vortex flows resembling downbursts are mentioned.

  15. Pro-apoptotic effect of new quinolone 7- ethyl 9-ethyl-6-oxo-6,9-dihydro[1,2,5]selenadiazolo [3,4-h]quinoline-7-carboxylate on cervical cancer cell line HeLa alone/with UVA irradiation.

    PubMed

    Jantová, Soňa; Mrvová, Nataša; Hudec, Roman; Sedlák, Ján; Pánik, Miroslav; Milata, Viktor

    2016-06-01

    7- ethyl 9-ethyl-6-oxo-6,9-dihydro[1,2,5]selenadiazolo [3,4-h]quinoline-7-carboxylate (E2h) is a new synthetically prepared quinolone derivative, which in our primary study showed cytotoxic effects towards tumor cells. The aim of the present study was to examine the antiproliferative and apoptosis inducing activities of E2h towards human cervical cancer cell line HeLa with/without the presence of UVA irradiation. Further, the molecular mechanism involved in E2h-induced apoptosis in HeLa cells was investigated. Our results showed that both non-photoactivated and photoactivated E2h caused morphological changes and inhibited the cell growth of HeLa cells in a time- and dose-dependent manner. Irradiation increased the sensitivity of HeLa cells to E2h. Quinolone induced S and G2/M arrest and apoptosis in HeLa cells, as characterized by DNA fragmentation and flow cytometry. In addition, E2h elevated the level of reactive oxygen species and activated caspases 3. In conclusions, E2h alone/in combination with UVA irradiation induced apoptosis in HeLa cells through the ROS-mitochondrial/caspase 3-dependent pathway.

  16. Teaching the principles of robotics at UVA

    SciTech Connect

    Inigo, R.M.

    1983-01-01

    A description is given of a graduate course in robotics, at the University of Virginia, which covers mechanics (kinematics and dynamics), control theory, machine vision and artificial intelligence, and computer language for simulation and control, among other subjects. Future objectives are outlined. 4 references.

  17. UV-A Curable Aerospace Topcoats

    DTIC Science & Technology

    2011-02-01

    UV -A Curable Aerospace Topcoats Mike Dvorchak Chuck Gambino Coatings , Adhesives, and Specialties Todd Williams Mike Gallagher Alan Bushmire Katrina... curable stencil coating for aircraft (’07) Evaluated by CTIO – Reduce gloss – Increase flexibility – Match color (Deft) Weathering of UV -A...Stencil Coatings on C-130 ΔE reduction in UV coatings most likely due to self cleaning – reduced film thickness over time Fluorourethane

  18. The major histocompatibility complex genes impact pain response in DA and DA.1U rats.

    PubMed

    Guo, Yuan; Yao, Fan-Rong; Cao, Dong-Yuan; Li, Li; Wang, Hui-Sheng; Xie, Wen; Zhao, Yan

    2015-08-01

    Our recent studies have shown that the difference in basal pain sensitivity to mechanical and thermal stimulation between Dark-Agouti (DA) rats and a novel congenic DA.1U rats is major histocompatibility complex (MHC) genes dependent. In the present study, we further used DA and DA.1U rats to investigate the role of MHC genes in formalin-induced pain model by behavioral, electrophysiological and immunohistochemical methods. Behavioral results showed biphasic nociceptive behaviors increased significantly following the intraplantar injection of formalin in the hindpaw of DA and DA.1U rats. The main nociceptive behaviors were lifting and licking, especially in DA rats (P<0.001 and P<0.01). The composite pain scores (CPS) in DA rats were significantly higher than those in DA.1U rats in both phases of the formalin test (P<0.01). Electrophysiological results also showed the biphasic increase in discharge rates of C and Aδ fibers of L5 dorsal root in the two strains, and the net change of the discharge rate of DA rats was significantly higher than that of DA.1U rats (P<0.05). The mechanical thresholds decreased after formalin injection in both strains (P<0.01), and the net change in the mechanical threshold in DA was greater than that in DA.1U rats (P<0.05). The expression of RT1-B, representation of MHC class II molecule, in laminae I-II of L4/5 spinal cord in DA rats was significantly higher than that in DA.1U rats in the respective experimental group (P<0.05). These results suggested that both DA and DA.1U rats exhibited nociceptive responses in formalin-induced pain model and DA rats were more sensitive to noxious chemical stimulus than DA.1U rats, indicating that MHC genes might contribute to the difference in pain sensitivity.

  19. Promoting La Cultura Hispana

    ERIC Educational Resources Information Center

    Pluviose, David

    2007-01-01

    Launched in 1985 at Arizona State University, the Hispanic Research Center's (HRC) efforts to promote Latino and Chicano art and issues have flourished in recent years. In 2004, the HRC hosted the Arizona International Latina/o Arts Festival in collaboration with the Mesa Southwest Museum. The HRC has also founded a mentoring institute for…

  20. Autocorrelation descriptor improvements for QSAR: 2DA_Sign and 3DA_Sign

    NASA Astrophysics Data System (ADS)

    Sliwoski, Gregory; Mendenhall, Jeffrey; Meiler, Jens

    2016-03-01

    Quantitative structure-activity relationship (QSAR) is a branch of computer aided drug discovery that relates chemical structures to biological activity. Two well established and related QSAR descriptors are two- and three-dimensional autocorrelation (2DA and 3DA). These descriptors encode the relative position of atoms or atom properties by calculating the separation between atom pairs in terms of number of bonds (2DA) or Euclidean distance (3DA). The sums of all values computed for a given small molecule are collected in a histogram. Atom properties can be added with a coefficient that is the product of atom properties for each pair. This procedure can lead to information loss when signed atom properties are considered such as partial charge. For example, the product of two positive charges is indistinguishable from the product of two equivalent negative charges. In this paper, we present variations of 2DA and 3DA called 2DA_Sign and 3DA_Sign that avoid information loss by splitting unique sign pairs into individual histograms. We evaluate these variations with models trained on nine datasets spanning a range of drug target classes. Both 2DA_Sign and 3DA_Sign significantly increase model performance across all datasets when compared with traditional 2DA and 3DA. Lastly, we find that limiting 3DA_Sign to maximum atom pair distances of 6 Å instead of 12 Å further increases model performance, suggesting that conformational flexibility may hinder performance with longer 3DA descriptors. Consistent with this finding, limiting the number of bonds in 2DA_Sign from 11 to 5 fails to improve performance.

  1. Percepcion de los profesores universitarios acerca del concepto cultura cientifica y de sus implicaciones en el nuevo bachillerato del Recinto de Rio Piedras de la Universidad de Puerto Rico

    NASA Astrophysics Data System (ADS)

    Ramos Pastrana, Nilsa

    El Senado Academico del Recinto de Rio Piedras de la Universidad de Puerto Rico aprobo en el ano academico 2005-2006 la Certificacion 46, que contiene los lineamientos de un nuevo bachillerato. Este nuevo bachillerato introdujo cambios significativos en el curriculo tradicional. Entre ellos se encuentra la reduccion del componente de educacion general y el de Ciencias Biologicas en particular. La reduccion de creditos en el componente de Ciencias Biologicas ha obligado a reevaluar el concepto de cultura cientifica que desarrollan esos cursos. El proposito del estudio consistio en auscultar las percepciones de los profesores de las Facultades de Administracion de Empresas, Humanidades, Ciencias Sociales, Ciencias Naturales, Educacion y Estudios Generales del Recinto de Rio Piedras de la Universidad de Puerto Rico en torno al concepto de cultura cientifica, los contenidos disciplinares del curso de Ciencias Biologicas y la reduccion de creditos en el nuevo bachillerato. Las preguntas que guiaron la investigacion fueron: ¿cuales son las percepciones que tienen los profesores de las Facultades de Administracion de Empresas, Ciencias Sociales, Estudios Generales, Ciencias Naturales, Humanidades y Educacion, en torno al concepto de cultura cientifica y los contenidos disciplinares del curso de Ciencias Biologicas? ¿cuales son las percepciones que tienen los profesores de Ciencias Biologicas en torno al concepto cultura cientifica y los contenidos disciplinares del curso de Ciencias Biologicas? ¿existen diferencias significativas por facultad, genero, experiencia, rango y nombramiento en las percepciones que tienen los profesores del Recinto de Rio Piedras de la Universidad de Puerto Rico sobre los elementos que caracterizan la cultura cientifica y los contenidos biologicos que deben tener los egresados del Recinto? ¿que implicaciones curriculares tienen estos testimonios en el desarrollo del concepto de cultura cientifica en el nuevo bachillerato? Para realizar la

  2. The potentially dangerous asteroid 2012 DA14

    NASA Astrophysics Data System (ADS)

    Wlodarczyk, I.

    2012-12-01

    We present computing methods that allow us to study the behaviour of the dynamically interesting potentially dangerous asteroid 2012 DA14. Using the freely available ORBFIT software, we can follow the orbit of the asteroid backward and forward in the future, searching for close approaches to the Earth that might lead to possible impacts. The possible impact orbit for 2026 is computed. We show that it should be possible to recover asteroid 2012 DA14, mainly in 2013 February. It is highly unlikely that asteroid 2012 DA14 will hit any geosynchronous satellites during its close approach on 2013 February 15.

  3. Origin of the DA and non-DA white dwarf stars

    NASA Technical Reports Server (NTRS)

    Shipman, Harry L.

    1989-01-01

    Various proposals for the bifurcation of the white dwarf cooling sequence are reviewed. 'Primordial' theories, in which the basic bifurcation of the white dwarf sequence is rooted in events predating the white dwarf stage of stellar evolution, are discussed, along with the competing 'mixing' theories in which processes occurring during the white dwarf stage are responsible for the existence of DA or non-DA stars. A new proposal is suggested, representing a two-channel scenario. In the DA channel, some process reduces the hydrogen layer mass to the value of less than 10 to the -7th. The non-DA channel is similar to that in the primordial scenario. These considerations suggest that some mechanism operates in both channels to reduce the thickness of the outermost layer of the white dwarf. It is also noted that accretion from the interstellar medium has little to do with whether a particular white dwarf becomes a DA or a non-DA star.

  4. An extension of PPLS-DA for classification and comparison to ordinary PLS-DA.

    PubMed

    Telaar, Anna; Liland, Kristian Hovde; Repsilber, Dirk; Nürnberg, Gerd

    2013-01-01

    Classification studies are widely applied, e.g. in biomedical research to classify objects/patients into predefined groups. The goal is to find a classification function/rule which assigns each object/patient to a unique group with the greatest possible accuracy (classification error). Especially in gene expression experiments often a lot of variables (genes) are measured for only few objects/patients. A suitable approach is the well-known method PLS-DA, which searches for a transformation to a lower dimensional space. Resulting new components are linear combinations of the original variables. An advancement of PLS-DA leads to PPLS-DA, introducing a so called 'power parameter', which is maximized towards the correlation between the components and the group-membership. We introduce an extension of PPLS-DA for optimizing this power parameter towards the final aim, namely towards a minimal classification error. We compare this new extension with the original PPLS-DA and also with the ordinary PLS-DA using simulated and experimental datasets. For the investigated data sets with weak linear dependency between features/variables, no improvement is shown for PPLS-DA and for the extensions compared to PLS-DA. A very weak linear dependency, a low proportion of differentially expressed genes for simulated data, does not lead to an improvement of PPLS-DA over PLS-DA, but our extension shows a lower prediction error. On the contrary, for the data set with strong between-feature collinearity and a low proportion of differentially expressed genes and a large total number of genes, the prediction error of PPLS-DA and the extensions is clearly lower than for PLS-DA. Moreover we compare these prediction results with results of support vector machines with linear kernel and linear discriminant analysis.

  5. Investigaccion-accion en la sala de clases sobre las creencias de la cultura de la ciencia de un grupo de estudiantes universitarios y su relacion reciproca con el aprendizaje de las ciencias biologicas

    NASA Astrophysics Data System (ADS)

    Cordova-Santiago, Lizzette Astrid

    La investigacion---accion que se llevo a cabo en la sala de clases tenia como punto de partida las creencias de la cultura de la ciencia de un grupo de estudiantes universitarios para luego examinar sus implicaciones en el proceso de aprendizaje de las Ciencias Biologicas. ¿Que se supone que hagan las creencias en relacion con el aprendizaje? ¿En que consiste incorporar este aspecto a la practica educativa universitaria? Utilizando el modelo de Kemmis y McTaggart (1987) la investigacion-accion se planteo como un proceso dinamico en cuatro momentos en espiral constituidos por la planificacion, la accion, la observacion y la reflexion. Cada una de las fases tuvo una intencion retrospectiva y prospectiva formando una espiral de autorreflexion del conocimiento y la accion. Se llevaron a cabo audio grabaciones en clases y analisis de documentos. Ademas, la profesora-investigadora hizo un portafolio para reflexionar sobre las creencias de la cultura de la ciencia que tienen los estudiantes y las creencias del aprendizaje que tiene la profesora y sobre como la comprension de estos elementos ayudo a mejorar su practica educativa a traves del tiempo. Los resultados obtenidos apuntan a que las creencias de la cultura de la ciencia que tiene el grupo de estudiantes son diversas. Ellos si creen que la ciencia tiene una cultura la cual describieron como: complicada y desconocida que evoluciona constantemente, que es un conjunto de metodos, que es altamente tecnologica, que resuelve problemas de salud, ayuda a interpretar la realidad del mundo que los rodea y su origen y que existen unas intersecciones entre la ciencia y el poder. Sobre las creencias del proceso de aprendizaje de la profesora-investigadora, estas senalan que el modelaje de actores, la vision de la academia que tiene ella asi como la participacion y negociacion entre todos los involucrados en el proceso educativo, son factores que inciden en el proceso de aprendizaje.

  6. DA white dwarfs in the Kepler field

    NASA Astrophysics Data System (ADS)

    Doyle, T. F.; Howell, S. B.; Petit, V.; Lépine, S.

    2017-01-01

    We present 16 new, and confirm 7 previously identified, DA white dwarfs in the Kepler field through ground-based spectroscopy with the Hale 200″, Kitt Peak 4-m, and Bok 2.3-m telescopes. Using atmospheric models, we determine their effective temperatures and surface gravities to constrain their position with respect to the ZZ Ceti (DA pulsator) instability strip, and look for the presence or absence of pulsation with Kepler's unprecedented photometry. Our results are as follows. (i) From our measurements of temperature and surface gravity, 12 of the 23 DA white dwarfs from this work fall well outside of the instability strip. The Kepler photometry available for 11 of these WDs allows us to confirm that none are pulsating. One of these 11 happens to be a presumed binary, KIC 11604781, with a period of ˜5 d. (ii) The remaining 11 DA white dwarfs are instability strip candidates, potentially falling within the current, empirical instability strip, after accounting for uncertainties. These WDs will help constrain the strip's location further, as eight are near the blue edge and three are near the red edge of the instability strip. Four of these WDs do not have Kepler photometry, so ground-based photometry is needed to determine the pulsation nature of these white dwarfs. The remaining seven have Kepler photometry available, but do not show any periodicity on typical WD pulsation time-scales.

  7. How to Think Like Leonardo da Vinci

    ERIC Educational Resources Information Center

    Caouette, Ralph

    2008-01-01

    To be effective and relevant in twenty-first-century learning, art needs to be more inclusive. In this article, the author discusses how teachers can find a good example in Leonardo da Vinci for building an art program. His art, design, and curiosity are the perfect foundation for any art program, at any level. (Contains 3 resources and 3 online…

  8. Hidden sketches by Leonardo da Vinci revealed

    NASA Astrophysics Data System (ADS)

    Dumé, Belle

    2009-02-01

    Three drawings on the back of Leonardo da Vinci's The Virgin and Child with St Anne (circa 1508) have been discovered by researchers led by Michel Menu from the Centre de Recherche et de Restauration des Musées de France (C2RMF) and the Louvre Museum in Paris.

  9. The local effect of octreotide on mechanical pain sensitivity is more sensitive in DA rats than DA.1U rats.

    PubMed

    Yao, Fan-Rong; Wang, Hui-Sheng; Guo, Yuan; Zhao, Yan

    2016-02-01

    A recent study by the authors indicated that major histocompatibility complex (MHC) genes are associated with the differences in basal pain sensitivity and in formalin model between Dark-Agouti (DA) and novel congenic DA.1U rats, which have the same genetic background as DA rats except for the u alleles of MHC. The objective of the present study is to investigate whether there is a difference in the pristane-induced arthritis (PIA) model and local analgesic effect of octreotide (OCT) between DA and DA.1U rats. The hindpaw mechanical withdrawal threshold (MWT) and heat withdrawal latency (HWL) were observed. The C unit firings of the tibial nerve evoked by non-noxious and noxious toe movements were recorded by electrophysiological methods in normal and PIA models in DA and DA.1U rats before and after local OCT administration. The expression of somatostatin receptor 2A (SSTR2A) was observed by immunohistochemistry. The results demonstrate that DA rats have a higher mechanical sensitivity than DA.1U rats after PIA. Local OCT administration significantly elevated MWT in DA rats under normal and PIA sate, but not in DA.1U rats. The electrophysiological experiments showed OCT significantly attenuated the firings of C units evoked by non-noxious and noxious stimulation in DA rats more than those in DA.1U rats both in normal and PIA states. In addition, the expression of SSTR2A in the dorsal horn of the spinal cord was significantly higher in DA than in DA.1U rats. All of the findings suggest a higher local analgesic effect of OCT in DA rats than DA.1U rats, which might be associated with the MHC genes.

  10. A Day in the Life at DaVita Academy

    ERIC Educational Resources Information Center

    Weinstein, Margery

    2010-01-01

    When a company name means "giving life," the bar for learning and development programs is held high. In this article, the author describes what it takes to graduate from DaVita Academy, the soft skills training program dialysis services company DaVita offers all its employees. DaVita's chief executive officer, Kent Thiry, states that the Academy…

  11. 32 CFR 516.25 - DA Form 4.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 3 2010-07-01 2010-07-01 true DA Form 4. 516.25 Section 516.25 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY AID OF CIVIL AUTHORITIES AND PUBLIC RELATIONS LITIGATION Reporting Legal Proceedings to HQDA § 516.25 DA Form 4. (a) General. The DA Form 4 (See figure...

  12. PanDA for COMPASS at JINR

    NASA Astrophysics Data System (ADS)

    Petrosyan, A. Sh.

    2016-09-01

    PanDA (Production and Distributed Analysis System) is a workload management system, widely used for data processing at experiments on Large Hadron Collider and others. COMPASS is a high-energy physics experiment at the Super Proton Synchrotron. Data processing for COMPASS runs locally at CERN, on lxbatch, the data itself stored in CASTOR. In 2014 an idea to start running COMPASS production through PanDA arose. Such transformation in experiment's data processing will allow COMPASS community to use not only CERN resources, but also Grid resources worldwide. During the spring and summer of 2015 installation, validation and migration work is being performed at JINR. Details and results of this process are presented in this paper.

  13. DA 495: An Aging Pulsar Wind Nebula

    NASA Astrophysics Data System (ADS)

    Kothes, R.; Landecker, T. L.; Reich, W.; Safi-Harb, S.; Arzoumanian, Z.

    2008-11-01

    We present a radio continuum study of the pulsar wind nebula (PWN) DA 495 (G65.7+1.2), including images of total intensity and linear polarization from 408 to 10550 MHz based on the Canadian Galactic Plane Survey and observations with the Effelsberg 100 m Radio Telescope. Removal of flux density contributions from a superimposed H II region and from compact extragalactic sources reveals a break in the spectrum of DA 495 at 1.3 GHz, with a spectral index α = - 0.45 +/- 0.20 below the break and α = - 0.87 +/- 0.10 above it (Sν propto να). The spectral break is more than 3 times lower in frequency than the lowest break detected in any other PWN. The break in the spectrum is likely the result of synchrotron cooling, and DA 495, at an age of ~20,000 yr, may have evolved from an object similar to the Vela X nebula, with a similarly energetic pulsar. We find a magnetic field of ~1.3 mG inside the nebula. After correcting for the resulting high internal rotation measure, the magnetic field structure is quite simple, resembling the inner part of a dipole field projected onto the plane of the sky, although a toroidal component is likely also present. The dipole field axis, which should be parallel to the spin axis of the putative pulsar, lies at an angle of ~50° east of the north celestial pole and is pointing away from us toward the southwest. The upper limit for the radio surface brightness of any shell-type supernova remnant emission around DA 495 is Σ1GHz ~ 5.4 × 10-23 W m-2 Hz-1 sr-1 (assuming a radio spectral index of α = - 0.5), lower than the faintest shell-type remnant known to date.

  14. [Leonardo da Vinci--a dyslectic genius?].

    PubMed

    Røsstad, Anna

    2002-12-10

    Leonardo da Vinci's texts consist almost exclusively of scientific notes. Working on a book on Leonardo's art, I studied all Leonardo's published texts carefully for any new information. In some prefaces I came to suspect that Leonardo might have suffered from dyslexia. This article considers the question of whether it is possible to find indications of dyslexia in Leonardo's texts and in the accounts of his life.

  15. Leonardo da Vinci's studies of the heart.

    PubMed

    Shoja, Mohammadali M; Agutter, Paul S; Loukas, Marios; Benninger, Brion; Shokouhi, Ghaffar; Namdar, Husain; Ghabili, Kamyar; Khalili, Majid; Tubbs, R Shane

    2013-08-20

    Leonardo da Vinci's detailed drawings are justly celebrated; however, less well known are his accounts of the structures and functions of the organs. In this paper, we focus on his illustrations of the heart, his conjectures about heart and blood vessel function, his experiments on model systems to test those conjectures, and his unprecedented conclusions about the way in which the cardiovascular system operates. In particular, da Vinci seems to have been the first to recognize that the heart is a muscle and that systole is the active phase of the pump. He also seems to have understood the functions of the auricles and pulmonary veins, identified the relationship between the cardiac cycle and the pulse, and explained the hemodynamic mechanism of valve opening and closure. He also described anatomical variations and changes in structure and function that occurred with age. We outline da Vinci's varied career and suggest ways in which his personality, experience, skills and intellectual heritage contributed to these advances in understanding. We also consider his influence on later studies in anatomy and physiology.

  16. Rational design of D-A1-D-A2 conjugated polymers with superior spectral coverage.

    PubMed

    Hedström, Svante; Tao, Qiang; Wang, Ergang; Persson, Petter

    2015-10-28

    The spectral coverage of a light-harvesting polymer largely determines the maximum achievable photocurrent in organic photovoltaics, and therefore constitutes a crucial parameter for improving their performance. The D-A1-D-A2 copolymer motif is a new and promising design strategy for extending the absorption range by incorporating two acceptor units with complementary photoresponses. The fundamental factors that promote an extended absorption are here determined for three prototype D-A1-D-A2 systems through a combination of experimental and computational methods. Systematic quantum chemical calculations are then used to reveal the intrinsic optical properties of ten further D-A1-D-A2 polymer candidates. These investigated polymers are all predicted to exhibit intense primary absorption peaks at 615-954 nm, corresponding to charge-transfer (CT) transitions to the stronger acceptor, as well as secondary absorption features at 444-647 nm that originate from CT transitions to the weaker acceptors. Realization of D-A1-D-A2 polymers with superior spectral coverage is thereby found to depend critically on the spatial and energetic separation between the two distinct acceptor LUMOs. Two promising D-A1-D-A2 copolymer candidates were finally selected for further theoretical and experimental study, and demonstrate superior light-harvesting properties in terms of significantly extended spectral coverage. This demonstrates great potential for enhanced light-harvesting in D-A1-D-A2 polymers via multiple absorption features compared to traditional D-A polymers.

  17. Polarization-switching D/A converter.

    PubMed

    Sun, Shunming; Kalkur, Thottam S

    2005-05-01

    This paper describes a novel digital-to-analog (D/A) conversion technique, which uses the analog quantity polarization as a D/A conversion medium. It can be implemented by CMOS capacitors or by ferroelectric capacitors, which exhibit strong nonlinearity in charge versus voltage behavior. Because a ferroelectric material inherently has spontaneous polarization and generally has a large dielectric constant, the effective capacitance of a ferroelectric capacitor is much larger than that of a CMOS capacitor of the same size. This ensures less influence of bottom-electrode parasitic capacitance on a ferroelectric capacitor. Furthermore, a data converter based on ferroelectric capacitors possesses the potential nonvolatile memory function owing to ferroelectric hysteresis. Along with the architecture proposed for polarization-switching digital-to-analog converter (PDAC), its circuit implementation is introduced. Described is implementation of two 9-bit bipolar PDACs: one is based on CMOS capacitors and the other on off-chip ferroelectric capacitors. Experimental results are presented for the performance of these two prototypes.

  18. The Case: Bunche-Da Vinci Learning Partnership Academy

    ERIC Educational Resources Information Center

    Eisenberg, Nicole; Winters, Lynn; Alkin, Marvin C.

    2005-01-01

    The Bunche-Da Vinci case described in this article presents a situation at Bunche Elementary School that four theorists were asked to address in their evaluation designs (see EJ791771, EJ719772, EJ791773, and EJ792694). The Bunche-Da Vinci Learning Partnership Academy, an elementary school located between an urban port city and a historically…

  19. DA-6034 Induces [Ca(2+)]i Increase in Epithelial Cells.

    PubMed

    Yang, Yu-Mi; Park, Soonhong; Ji, Hyewon; Kim, Tae-Im; Kim, Eung Kweon; Kang, Kyung Koo; Shin, Dong Min

    2014-04-01

    DA-6034, a eupatilin derivative of flavonoid, has shown potent effects on the protection of gastric mucosa and induced the increases in fluid and glycoprotein secretion in human and rat corneal and conjunctival cells, suggesting that it might be considered as a drug for the treatment of dry eye. However, whether DA-6034 induces Ca(2+) signaling and its underlying mechanism in epithelial cells are not known. In the present study, we investigated the mechanism for actions of DA-6034 in Ca(2+) signaling pathways of the epithelial cells (conjunctival and corneal cells) from human donor eyes and mouse salivary gland epithelial cells. DA-6034 activated Ca(2+)-activated Cl(-) channels (CaCCs) and increased intracellular calcium concentrations ([Ca(2+)]i) in primary cultured human conjunctival cells. DA-6034 also increased [Ca(2+)]i in mouse salivary gland cells and human corneal epithelial cells. [Ca(2+)]i increase of DA-6034 was dependent on the Ca(2+) entry from extracellular and Ca(2+) release from internal Ca(2+) stores. Interestingly, these effects of DA-6034 were related to ryanodine receptors (RyRs) but not phospholipase C/inositol 1,4,5-triphosphate (IP3) pathway and lysosomal Ca(2+) stores. These results suggest that DA-6034 induces Ca(2+) signaling via extracellular Ca(2+) entry and RyRs-sensitive Ca(2+) release from internal Ca(2+) stores in epithelial cells.

  20. 32 CFR 643.121 - Private organizations on DA installations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 4 2011-07-01 2011-07-01 false Private organizations on DA installations. 643... (CONTINUED) REAL PROPERTY REAL ESTATE Additional Authority of Commanders § 643.121 Private organizations on DA installations. (a) AR 210-1 defines and classifies private organizations, such as thrift shops...

  1. NASA-UVA light aerospace alloy and structures technology program

    NASA Technical Reports Server (NTRS)

    Gangloff, Richard P.; Haviland, John K.; Herakovich, Carl T.; Pilkey, Walter D.; Pindera, Marek-Jerzy; Stoner, Glenn E.; Swanson, Robert E.; Thornton, Earl A.; Wawner, Franklin E., Jr.; Wert, John A.

    1990-01-01

    The objective of the Light Aerospace Alloy and Structures Technology Program is to conduct interdisciplinary graduate student research on the performance of next generation, light weight aerospace alloys, composites, and associated thermal gradient structures. Individual technical objectives are established for each project. Efforts aim to produce basic understanding of material behavior, monolithic and composite alloys, processing methods, solid and mechanics analyses, measurement advances, and a pool of educated graduate students. Progress is reported for 11 areas of study.

  2. Da Costa's syndrome or neurocirculatory asthenia.

    PubMed Central

    Paul, O

    1987-01-01

    The syndrome variously called Da Costa's syndrome, effort syndrome, neurocirculatory asthenia, etc has been studied for more than 100 years by many distinguished physicians. Originally identified in men in wartime, it has been widely recognised as a common chronic condition in both sexes in civilian life. Although the symptoms may seem to appear after infections and various physical and psychological stresses, neurocirculatory asthenia is most often encountered as a familial disorder that is unrelated to these factors, although they may aggravate an existing tendency. Respiratory complaints (including breathlessness, with and without effort, and smothering sensations) are almost universal, and palpitation, chest discomfort, dizziness and faintness, and fatigue are common. The physical examination is normal. The aetiology is obscure but patients usually have a normal life span. Reassurance and measures to improve physical fitness are helpful. PMID:3314950

  3. Leonardo da Vinci's contributions to neuroscience.

    PubMed

    Pevsner, Jonathan

    2002-04-01

    Leonardo da Vinci (1452-1519) made far-reaching contributions to many areas of science, technology and art. Leonardo's pioneering research into the brain led him to discoveries in neuroanatomy (such as those of the frontal sinus and meningeal vessels) and neurophysiology (he was the first to pith a frog). His injection of hot wax into the brain of an ox provided a cast of the ventricles, and represents the first known use of a solidifying medium to define the shape and size of an internal body structure. Leonardo developed an original, mechanistic model of sensory physiology. He undertook his research with the broad goal of providing physical explanations of how the brain processes visual and other sensory input, and integrates that information via the soul.

  4. 75 FR 52292 - Airworthiness Directives; Diamond Aircraft Industries GmbH Models DA 40 and DA 40F Airplanes

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-08-25

    ... Directives; Diamond Aircraft Industries GmbH Models DA 40 and DA 40F Airplanes AGENCY: Federal Aviation...: We propose to adopt a new airworthiness directive (AD) for all Diamond Aircraft Industries GmbH... Federal holidays. For service information identified in this proposed AD, contact Diamond...

  5. Current Status of the Hot White Dwarf Luminosity Function and non-DA to DA Ratio from SDSS Data

    NASA Astrophysics Data System (ADS)

    Krzesinski, J.; Stachowski, G.

    2017-03-01

    Recent advances in the determination of the hot white dwarf (WD) luminosity function have reached the point where we have good agreement between the observed and theoretical DA and non-DA LFs for WDs from SDSS DR4. The main progress in calculation of the DA LF was obtained when the WD sample was restricted to only carbon-oxygen core WDs. However, one remaining effect which could influence the LF and the non-DA to DA ratio is the difference in visibility of helium- and hydrogen-atmosphere WDs in a magnitude-limited sample. In this work we explore this effect for the SDSS g filter as a function of effective temperature, as well as make an attempt to evaluate data relevant to the WD sample and LFs from more recent data releases of the SDSS.

  6. Der Telemanipulator daVinci als mechanisches Trackingsystem

    NASA Astrophysics Data System (ADS)

    Käst, Johannes; Neuhaus, Jochen; Nickel, Felix; Kenngott, Hannes; Engel, Markus; Short, Elaine; Reiter, Michael; Meinzer, Hans-Peter; Maier-Hein, Lena

    Der Telemanipulator daVinci (Intuitive Surgical, Sunnyvale, Kalifornien) ist ein M aster-Slave System für roboterassistierte minimalinvasive Chirurgie. Da er über integrierte Gelenksensoren verfügt, kann er unter Verwendung der daVinci-API als mechanisches Trackingsystem verwendet werden. In dieser Arbeit evaluieren wir die Präzision und Genauigkeit eines daVinci mit Hilfe eines Genauigkeitsphantoms mit bekannten Maßen. Der ermittelte Positionierungsfehler liegt in der Größenordnung von 6 mm und ist somit für einen Großteil der medizinischen Fragestellungen zu hoch. Zur Reduktion des Fehlers schlagen wir daher eine Kalibrierung der Gelenksensoren vor.

  7. 40 CFR 60.51Da - Reporting requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... Generating Units § 60.51Da Reporting requirements. (a) For SO2, NOX, PM, and NOX plus CO emissions, the... emission rates (so) and inlet emission rates (si) as applicable. (3) The lower confidence limit for...

  8. 40 CFR 60.51Da - Reporting requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... Generating Units § 60.51Da Reporting requirements. (a) For SO2, NOX, PM, and NOX plus CO emissions, the... emission rates (so) and inlet emission rates (si) as applicable. (3) The lower confidence limit for...

  9. Tree branching: Leonardo da Vinci's rule versus biomechanical models.

    PubMed

    Minamino, Ryoko; Tateno, Masaki

    2014-01-01

    This study examined Leonardo da Vinci's rule (i.e., the sum of the cross-sectional area of all tree branches above a branching point at any height is equal to the cross-sectional area of the trunk or the branch immediately below the branching point) using simulations based on two biomechanical models: the uniform stress and elastic similarity models. Model calculations of the daughter/mother ratio (i.e., the ratio of the total cross-sectional area of the daughter branches to the cross-sectional area of the mother branch at the branching point) showed that both biomechanical models agreed with da Vinci's rule when the branching angles of daughter branches and the weights of lateral daughter branches were small; however, the models deviated from da Vinci's rule as the weights and/or the branching angles of lateral daughter branches increased. The calculated values of the two models were largely similar but differed in some ways. Field measurements of Fagus crenata and Abies homolepis also fit this trend, wherein models deviated from da Vinci's rule with increasing relative weights of lateral daughter branches. However, this deviation was small for a branching pattern in nature, where empirical measurements were taken under realistic measurement conditions; thus, da Vinci's rule did not critically contradict the biomechanical models in the case of real branching patterns, though the model calculations described the contradiction between da Vinci's rule and the biomechanical models. The field data for Fagus crenata fit the uniform stress model best, indicating that stress uniformity is the key constraint of branch morphology in Fagus crenata rather than elastic similarity or da Vinci's rule. On the other hand, mechanical constraints are not necessarily significant in the morphology of Abies homolepis branches, depending on the number of daughter branches. Rather, these branches were often in agreement with da Vinci's rule.

  10. ECTA/DaSy Framework Self-Assessment Comparison Tool

    ERIC Educational Resources Information Center

    Center for IDEA Early Childhood Data Systems (DaSy), 2016

    2016-01-01

    The Self-Assessment Comparison (SAC) Tool is for state Part C and Section 619/Preschool programs to use to assess changes in the implementation of one or more components of the ECTA System Framework and/or subcomponenets of the DaSy Data System Framework. It is a companion to the ECTA/DaSy Framework Self-Assessment. Key features of the SAC are…

  11. Mycobacterium tuberculosis 19-kDa lipoprotein promotes neutrophil activation.

    PubMed

    Neufert, C; Pai, R K; Noss, E H; Berger, M; Boom, W H; Harding, C V

    2001-08-01

    Certain microbial substances, e.g., LPS, can activate neutrophils or prime them to enhance their response to other activating agents, e.g., fMLP. We investigated the role of the Mycobacterium tuberculosis (MTB) 19-kDa lipoprotein in activation of human neutrophils. MTB 19-kDa lipoprotein initiated phenotypic changes characteristic of neutrophil activation, including down-regulation of CD62 ligand (L-selectin) and up-regulation of CD35 (CR1) and CD11b/CD18 (CR3, Mac-1). In addition, exposure of neutrophils to MTB 19-kDa lipoprotein enhanced the subsequent oxidative burst in response to fMLP as assessed by oxidation of dihydrorhodamine 123 (determined by flow cytometry). LPS also produced these effects with similar kinetics, but an oligodeoxynucleotide containing a CpG motif failed to induce any priming or activation response. Although the effects of LPS required the presence of serum, neutrophil activation by MTB 19-kDa lipoprotein occurred independently of serum factors, suggesting the involvement of different receptors and signaling mechanisms for LPS and MTB 19-kDa lipoprotein. Thus, MTB 19-kDa lipoprotein serves as a pathogen-associated molecular pattern that promotes neutrophil priming and activation.

  12. Migration of ATLAS PanDA to CERN

    NASA Astrophysics Data System (ADS)

    Stewart, Graeme Andrew; Klimentov, Alexei; Koblitz, Birger; Lamanna, Massimo; Maeno, Tadashi; Nevski, Pavel; Nowak, Marcin; Emanuel De Castro Faria Salgado, Pedro; Wenaus, Torre

    2010-04-01

    The ATLAS Production and Distributed Analysis System (PanDA) is a key component of the ATLAS distributed computing infrastructure. All ATLAS production jobs, and a substantial amount of user and group analysis jobs, pass through the PanDA system, which manages their execution on the grid. PanDA also plays a key role in production task definition and the data set replication request system. PanDA has recently been migrated from Brookhaven National Laboratory (BNL) to the European Organization for Nuclear Research (CERN), a process we describe here. We discuss how the new infrastructure for PanDA, which relies heavily on services provided by CERN IT, was introduced in order to make the service as reliable as possible and to allow it to be scaled to ATLAS's increasing need for distributed computing. The migration involved changing the backend database for PanDA from MySQL to Oracle, which impacted upon the database schemas. The process by which the client code was optimised for the new database backend is discussed. We describe the procedure by which the new database infrastructure was tested and commissioned for production use. Operations during the migration had to be planned carefully to minimise disruption to ongoing ATLAS offline computing. All parts of the migration were fully tested before commissioning the new infrastructure and the gradual migration of computing resources to the new system allowed any problems of scaling to be addressed.

  13. DaTo: an atlas of biological databases and tools.

    PubMed

    Li, Qilin; Zhou, Yincong; Jiao, Yingmin; Zhang, Zhao; Bai, Lin; Tong, Li; Yang, Xiong; Sommer, Björn; Hofestädt, Ralf; Chen, Ming

    2016-12-18

    This work presents DaTo, a semi-automatically generated world atlas of biological databases and tools. It extracts raw information from all PubMed articles which contain exact URLs in their abstract section, followed by a manual curation of the abstract and the URL accessibility. DaTo features a user-friendly query interface, providing extensible URL-related annotations, such as the status, the location and the country of the URL. A graphical interaction network browser has also been integrated into the DaTo web interface to facilitate exploration of the relationship between different tools and databases with respect to their ontology-based semantic similarity. Using DaTo, the geographical locations, the health statuses, as well as the journal associations were evaluated with respect to the historical development of bioinformatics tools and databases over the last 20 years. We hope it will inspire the biological community to gain a systematic insight into bioinformatics resources. DaTo is accessible via http://bis.zju.edu.cn/DaTo/.

  14. The Ubiquitin Receptor DA1 Interacts with the E3 Ubiquitin Ligase DA2 to Regulate Seed and Organ Size in Arabidopsis[C][W

    PubMed Central

    Xia, Tian; Li, Na; Dumenil, Jack; Li, Jie; Kamenski, Andrei; Bevan, Michael W.; Gao, Fan; Li, Yunhai

    2013-01-01

    Seed size in higher plants is determined by the coordinated growth of the embryo, endosperm, and maternal tissue. Several factors that act maternally to regulate seed size have been identified, such as AUXIN RESPONSE FACTOR2, APETALA2, KLUH, and DA1, but the genetic and molecular mechanisms of these factors in seed size control are almost totally unknown. We previously demonstrated that the ubiquitin receptor DA1 acts synergistically with the E3 ubiquitin ligase ENHANCER1 OF DA1 (EOD1)/BIG BROTHER to regulate the final size of seeds in Arabidopsis thaliana. Here, we describe another RING-type protein with E3 ubiquitin ligase activity, encoded by DA2, which regulates seed size by restricting cell proliferation in the maternal integuments of developing seeds. The da2-1 mutant forms large seeds, while overexpression of DA2 decreases seed size of wild-type plants. Overexpression of rice (Oryza sativa) GRAIN WIDTH AND WEIGHT2, a homolog of DA2, restricts seed growth in Arabidopsis. Genetic analyses show that DA2 functions synergistically with DA1 to regulate seed size, but does so independently of EOD1. Further results reveal that DA2 interacts physically with DA1 in vitro and in vivo. Therefore, our findings define the genetic and molecular mechanisms of three ubiquitin-related proteins DA1, DA2, and EOD1 in seed size control and indicate that they are promising targets for crop improvement. PMID:24045020

  15. PKC phosphorylates residues in the N-terminal of the DA transporter to regulate amphetamine-induced DA efflux.

    PubMed

    Wang, Qiang; Bubula, Nancy; Brown, Jason; Wang, Yunliang; Kondev, Veronika; Vezina, Paul

    2016-05-27

    The DA transporter (DAT), a phosphoprotein, controls extracellular dopamine (DA) levels in the central nervous system through transport or reverse transport (efflux). Multiple lines of evidence support the claim that PKC significantly contributes to amphetamine-induced DA efflux. Other signaling pathways, involving CaMKII and ERK, have also been shown to regulate DAT mediated efflux. Here we assessed the contribution of putative PKC residues (S4, S7, S13) in the N-terminal of the DAT to amphetamine-induced DA efflux by transfecting DATs containing different serine to alanine (S-A) point mutations into DA pre-loaded HEK-293 cells and incubating these cells in amphetamine (2μM). The effects of a S-A mutation at the non-PKC residue S12 and a threonine to alanine (T-A) mutation at the ERK T53 residue were also assessed for comparison. WT-DATs were used as controls. In an initial experiment, we confirmed that inhibiting PKC with Go6976 (130nM) significantly reduced amphetamine-induced DA efflux. In subsequent experiments, cells transfected with the S4A, S12A, S13A, T53A and S4,7,13A mutants showed a reduction in amphetamine-induced DA efflux similar to that observed with Go6976. Interestingly, cells transfected with the S7A mutant, identified by some as a PKC-PKA residue, showed unperturbed WT-DAT levels of amphetamine-induced DA efflux. These results indicate that phosphorylation by PKC of select residues in the DAT N-terminal can regulate amphetamine-induced efflux. PKC can act either independently or in concert with other kinases such as ERK to produce this effect.

  16. Secretion of 10-kDa and 12-kDa thioredoxin species from blood monocytes and transformed leukocytes.

    PubMed

    Sahaf, B; Rosén, A

    2000-01-01

    Thioredoxins (TRX) are ubiquitous, small redox-active proteins with multiple functions, including antioxidant, cytoprotective, and chemoattractant activities. In addition to a 12-kDa intracellular form, extracellular 10-kDa and 12-kDa TRX have been defined. The biological activities of the 10-kDa TRX were previously measured as eosinophil cytotoxicity enhancing activity or B-cell stimulatory activity. Cytotrophoblastic cell lines also release a 10-kDa TRX form. To study the biological role of 10-kDa TRX, we established two highly sensitive enzyme-linked immuno-spot assays (ELISPOT), which detect secreted truncated 10-kDa and full-length 12-kDa TRX at the single cell level. TRX secretion was investigated in several cell lines including the T-helper cell hybridoma MP6, the Jurkat T-cell leukemia, the U-937 myelomonocytic leukemia, and the 3B6, EBV-transformed, lymphoblastoid B-cell line. The highest number of secreting cells was found in 3B6 cultures, median = 34 (quartiles, 27-39) per well (10(5) cells). Peripheral blood monocytes isolated from healthy donors secreted significantly more TRX after stimulation with ionomycin, phorbol myristate acetate (PMA), fMLP, and lipopolysaccharide (LPS), compared to unstimulated cells. Oxidative stress induced by thioloxidant diamide also induced the secretion of both truncated and full-length TRX measured in ELISPOT (p = 0.047 and p = 0.031, respectively). The biological activity of the truncated and full-length forms was tested in a cell migration assay. Truncated TRX was devoid of protein disulfide reductase activity, but retained strong chemoattractant activity for human monocytes, in the same range as full-length TRX, as previously reported (Bertini et al., 1999).

  17. Purification and characterization of 94kDa and 80kDa forms of the muscarinic cholinergic receptor

    SciTech Connect

    Fracek, S.P. Jr.; Venter, J.C.; Kerlavage, A.R.

    1986-05-01

    Two molecular forms of the muscarinic cholinergic receptor have been consistently observed in a variety of species, albeit in variable amounts. Proteins which are specifically labeled by (/sup 3/H)propylbenzilylcholine mustard ((/sup 3/H)PrBCM) were observed at 94kDa and 80kDa upon SDS-PAGE of membrane proteins prepared from brains and hearts of trout, frog, turtle, chicken, rat, and pig. They have developed a purification procedure which yields each of these proteins in a homogeneous form suitable for structural analysis. The four step procedure involves affinity chromatography on 3-(2'-aminobenzhydryloxy)tropane-sepharose, concentration on hydroxylapatite, preparative SDS-PAGE and extraction of individual bands from the gel. Limited tryptic digestion of purified (/sup 3/H)PrBCM-labeled porcine atrial muscarinic receptor yields (/sup 3/H)-labeled fragments of 75, 65, 52, 40, 35, 30, 25, and 20kDa, in close agreement with results of analogous digestions of muscarinic receptor from other species and tissues. Complete tryptic digestion and subsequent mapping by reverse-phase HPLC yields very similar profiles for (/sup 125/I)-labeled 94kDa and 80kDA receptor forms. Most peaks which elute in the hydrophobic region of the profile overlap for the two proteins while the 94kDa protein contains several additional peaks of apparent low hydrophobicity.

  18. 76 FR 12627 - Airworthiness Directives; Diamond Aircraft Industries GmbH Models DA 42, DA 42 NG, and DA 42 M-NG...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-03-08

    ... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Diamond Aircraft... on Diamond aeroplanes, the majority of which were DA 40. In additional, at least 18 doors have been replaced because of damage found on the hinge. Diamond Aircraft Industries conducted analyses...

  19. A cosmologia no ensino da geografia

    NASA Astrophysics Data System (ADS)

    Santos, S. C.; Chiaradia, A. P. M.

    2003-08-01

    O principal objetivo deste trabalho é auxiliar o professor de Geografia em sala de aula no ensino de tópicos relacionados com a Cosmologia. A idéia deste trabalho surgiu quando foi constatado que o professor de Geografia tem dificuldades de ensinar este tópico. Esta constatação foi feita por uma das autoras ao lecionar este tópico no ensino fundamental e em discussões com outros professores de Geografia. Da mesma maneira que ocorria desde os tempos mais antigos, os alunos têm muito interesse em conhecer os fenômenos que ocorrem no Cosmo, porém os livros didáticos de Geografia utilizados em sala de aula não são ricos em informações sobre este assunto. Assim, o professor de Geografia tem poucas informações para discutir este assunto em sala de aula e não dá a devida importância para este tópico. Então, foi desenvolvido um material de apoio para professores de Geografia sobre a origem do Universo, sua evolução e seu possível futuro evolutivo segundo as mais recentes teorias, com base em perguntas feitas pelos alunos de ensino fundamental e as informações trazidas nos livros didáticos Não cabe a este material inovar e tão pouco trazer uma metodologia de ensino de Cosmologia. Neste material o professor de Geografia pode encontrará um banco de informações, que constitui no estabelecimento de conceitos, teorias e hipóteses, sobre a Cosmologia, em linguagem simples e de fácil entendimento. Para desenvolvê-lo, foram feitas pesquisas não exaustivas em livros e revistas científicas, compilação e discussão em forma cronológica das teorias aceitas sobre modelos cosmológicos. Portanto, este material será apresentado neste trabalho.

  20. Overview of ATLAS PanDA Workload Management

    NASA Astrophysics Data System (ADS)

    Maeno, T.; De, K.; Wenaus, T.; Nilsson, P.; Stewart, G. A.; Walker, R.; Stradling, A.; Caballero, J.; Potekhin, M.; Smith, D.; ATLAS Collaboration

    2011-12-01

    The Production and Distributed Analysis System (PanDA) plays a key role in the ATLAS distributed computing infrastructure. All ATLAS Monte-Carlo simulation and data reprocessing jobs pass through the PanDA system. We will describe how PanDA manages job execution on the grid using dynamic resource estimation and data replication together with intelligent brokerage in order to meet the scaling and automation requirements of ATLAS distributed computing. PanDA is also the primary ATLAS system for processing user and group analysis jobs, bringing further requirements for quick, flexible adaptation to the rapidly evolving analysis use cases of the early datataking phase, in addition to the high reliability, robustness and usability needed to provide efficient and transparent utilization of the grid for analysis users. We will describe how PanDA meets ATLAS requirements, the evolution of the system in light of operational experience, how the system has performed during the first LHC data-taking phase and plans for the future.

  1. The ATLAS PanDA Monitoring System and its Evolution

    NASA Astrophysics Data System (ADS)

    Klimentov, A.; Nevski, P.; Potekhin, M.; Wenaus, T.

    2011-12-01

    The PanDA (Production and Distributed Analysis) Workload Management System is used for ATLAS distributed production and analysis worldwide. The needs of ATLAS global computing imposed challenging requirements on the design of PanDA in areas such as scalability, robustness, automation, diagnostics, and usability for both production shifters and analysis users. Through a system-wide job database, the PanDA monitor provides a comprehensive and coherent view of the system and job execution, from high level summaries to detailed drill-down job diagnostics. It is (like the rest of PanDA) an Apache-based Python application backed by Oracle. The presentation layer is HTML code generated on the fly in the Python application which is also responsible for managing database queries. However, this approach is lacking in user interface flexibility, simplicity of communication with external systems, and ease of maintenance. A decision was therefore made to migrate the PanDA monitor server to Django Web Application Framework and apply JSON/AJAX technology in the browser front end. This allows us to greatly reduce the amount of application code, separate data preparation from presentation, leverage open source for tools such as authentication and authorization mechanisms, and provide a richer and more dynamic user experience. We describe our approach, design and initial experience with the migration process.

  2. Overview of ATLAS PanDA Workload Management

    SciTech Connect

    Maeno T.; De K.; Wenaus T.; Nilsson P.; Stewart G. A.; Walker R.; Stradling A.; Caballero J.; Potekhin M.; Smith D.

    2011-01-01

    The Production and Distributed Analysis System (PanDA) plays a key role in the ATLAS distributed computing infrastructure. All ATLAS Monte-Carlo simulation and data reprocessing jobs pass through the PanDA system. We will describe how PanDA manages job execution on the grid using dynamic resource estimation and data replication together with intelligent brokerage in order to meet the scaling and automation requirements of ATLAS distributed computing. PanDA is also the primary ATLAS system for processing user and group analysis jobs, bringing further requirements for quick, flexible adaptation to the rapidly evolving analysis use cases of the early datataking phase, in addition to the high reliability, robustness and usability needed to provide efficient and transparent utilization of the grid for analysis users. We will describe how PanDA meets ATLAS requirements, the evolution of the system in light of operational experience, how the system has performed during the first LHC data-taking phase and plans for the future.

  3. 1991 DA: An asteroid in a bizarre orbit

    NASA Technical Reports Server (NTRS)

    Steel, Duncan; Mcnaught, Robert H.; Asher, David

    1992-01-01

    Asteroidal object 1991 DA has an orbit of high inclination, crossing the planets from Mars to Uranus. This is unique for an asteroid, but not unusual for a comet of the Halley-type: it therefore seems likely that 1991 DA is an extinct or dormant comet. Previous CCD imaging has shown no indication of a coma; spectroscopic observations of 1991 DA which lack any evidence of strong comet-like emissions are reported. Numerical integrations of the orbit of this object were performed which show that is has been remarkably stable for the past approximately 20,000 yr, but chaotic before that. This may allow a new estimate to be made of the physical lifetimes of comets.

  4. Geomagnetic observations on tristan da cunha, south atlantic ocean

    USGS Publications Warehouse

    Matzka, J.; Olsen, N.; Maule, C.F.; Pedersen, L.W.; Berarducci, A.M.; Macmillan, S.

    2009-01-01

    Few geomagnetic ground observations exist of the Earth's strongest core field anomaly, the South Atlantic Anomaly (SAA). The geomagnetic repeat station on the island Tristan da Cunha, located half-way between South Africa and South America at 37?? 05' S, 12?? 18' W, is therefore of crucial importance. We have conducted several sets of repeat station measurements during magnetically quiet conditions (Kp 2o or less) in 2004. The procedures are described and the results are compared to those from earlier campaigns and to the predictions of various global field models. Features of the local crustal bias field and the solar quiet daily variation are discussed. We also evaluate the benefit of continuous magnetic field recordings from Tristan da Cunha, and argue that such a data set is a very valuable addition to geomagnetic satellite data. Recently, funds were set up to establish and operate a magnetometer station on Tristan da Cunha during the Swarm magnetic satellite mission (2011-2014).

  5. The future of PanDA in ATLAS distributed computing

    NASA Astrophysics Data System (ADS)

    De, K.; Klimentov, A.; Maeno, T.; Nilsson, P.; Oleynik, D.; Panitkin, S.; Petrosyan, A.; Schovancova, J.; Vaniachine, A.; Wenaus, T.

    2015-12-01

    Experiments at the Large Hadron Collider (LHC) face unprecedented computing challenges. Heterogeneous resources are distributed worldwide at hundreds of sites, thousands of physicists analyse the data remotely, the volume of processed data is beyond the exabyte scale, while data processing requires more than a few billion hours of computing usage per year. The PanDA (Production and Distributed Analysis) system was developed to meet the scale and complexity of LHC distributed computing for the ATLAS experiment. In the process, the old batch job paradigm of locally managed computing in HEP was discarded in favour of a far more automated, flexible and scalable model. The success of PanDA in ATLAS is leading to widespread adoption and testing by other experiments. PanDA is the first exascale workload management system in HEP, already operating at more than a million computing jobs per day, and processing over an exabyte of data in 2013. There are many new challenges that PanDA will face in the near future, in addition to new challenges of scale, heterogeneity and increasing user base. PanDA will need to handle rapidly changing computing infrastructure, will require factorization of code for easier deployment, will need to incorporate additional information sources including network metrics in decision making, be able to control network circuits, handle dynamically sized workload processing, provide improved visualization, and face many other challenges. In this talk we will focus on the new features, planned or recently implemented, that are relevant to the next decade of distributed computing workload management using PanDA.

  6. The DaCHS Multi-protocol VO Server

    NASA Astrophysics Data System (ADS)

    Demleitner, M.

    2014-05-01

    GAVO's Data Center Helper Suite (DaCHS) is a suite of tools for publishing data to the Virtual Observatory. It implements all major VO protocols (SCS, SIAP, SSAP, TAP, OAI-PMH). The integrated management and ingestion component allow defining metadata, structure, and services once and re-use the definition throughout the publication cycle from initial metadata aquisition to registry record generation. It has been driving GAVO's data center since 2008 and is now deployed in multiple locations around the globe. This poster briefly describes the design of the system as well as a bird's-eye view of data publishing with DaCHS.

  7. Using DA White Dwarfs to Calibrate Synthetic Photometry

    NASA Astrophysics Data System (ADS)

    Holberg, J. B.

    2007-04-01

    Four widely used photometric systems, namely the Johnson-Kron-Cousins UBVRI, the Strömgren uvby, the 2MASS JHKs and the Sloan Digital Sky Survey ugriz systems have been directly compared with the HST absolute photometric scale of Bohlin & Gilliland (2004). These comparisons are subsequently used to construct a large grid of accurate synthetic magnitudes for DA white dwarfs. This grid is, in turn, critically evaluated with respect to the observed photometry from substantial samples of actual white dwarfs. The advantages of DA white dwarfs as photometric stars are emphasized, and the prospects for extending the use of these stars into the near infrared are highlighted.

  8. 40 CFR 60.48Da - Compliance provisions.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... used in combined cycle systems, either of the procedures described in paragraph (j)(1) or (2) of this... (O2) (or carbon dioxide (CO2)) and meet the requirements of § 60.49Da. Alternatively, data from a NOX... shall constitute the NOX emission rate from the duct burner of the combined cycle system. (k)...

  9. 40 CFR 60.48Da - Compliance provisions.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... combined cycle systems, either of the procedures described in paragraph (j)(1) or (2) of this section may... carbon dioxide (CO2)) and meet the requirements of § 60.49Da. Alternatively, data from a NOX emission... shall constitute the NOX emission rate from the duct burner of the combined cycle system. (k)...

  10. 40 CFR 60.48Da - Compliance provisions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... using the CEMS specified under § 60.49Da for measuring NOX and oxygen (O2) (or carbon dioxide (CO2)) and... using electronic or other means (e.g., using a strip chart recorder or a data logger.) (C) The bag...

  11. 40 CFR 60.51Da - Reporting requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) STANDARDS OF PERFORMANCE FOR NEW STATIONARY SOURCES Standards of Performance for Electric Utility Steam Generating Units for Which Construction is Commenced After September 18, 1978 § 60.51Da Reporting... the quarter; reasons for non-compliance with the emission standards; and, description of...

  12. Studying and Working Abroad. Leonardo da Vinci Series: Good Practices.

    ERIC Educational Resources Information Center

    Commission of the European Communities, Brussels (Belgium). Directorate-General for Education and Culture.

    This document profiles recent successful examples of students studying and working abroad as part of the European Commission's Leonardo da Vinci program, which is designed to give students across the European Union the opportunity to experience vocational training in a foreign country. The following examples are presented: (1) 3 Finnish students…

  13. The DaVinci Project: Multimedia in Art and Chemistry.

    ERIC Educational Resources Information Center

    Simonson, Michael; Schlosser, Charles

    1998-01-01

    Provides an overview of the DaVinci Project, a collaboration of students, teachers, and researchers in chemistry and art to develop multimedia materials for grades 3-12 visualizing basic concepts in chemistry and visual art. Topics addressed include standards in art and science; the conceptual framework for the project; and project goals,…

  14. 40 CFR 60.47Da - Commercial demonstration permit.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Commercial demonstration permit. 60... Steam Generating Units for Which Construction is Commenced After September 18, 1978 § 60.47Da Commercial... technology may apply to the Administrator for a commercial demonstration permit. The Administrator will...

  15. The Potential da Vinci in All of Us

    ERIC Educational Resources Information Center

    Petto, Sarah; Petto, Andrew

    2009-01-01

    The study of the human form is fundamental to both science and art curricula. For vertebrates, perhaps no feature is more important than the skeleton to determine observable form and function. As Leonard da Vinci's famous Proportions of the Human Figure (Virtruvian Man) illustrates, the size, shape, and proportions of the human body are defined by…

  16. Training and Health. Leonardo da Vinci Series: Good Practices.

    ERIC Educational Resources Information Center

    Commission of the European Communities, Brussels (Belgium). Directorate-General for Education and Culture.

    This document profiles programs in the fields of health and medicine that are offered through the European Commission's Leonardo da Vinci program. The following programs are profiled: (1) CYTOTRAIN (a transnational vocational training program in cervical cancer screening); (2) Apollo (a program of open and distance learning for paramedical…

  17. Women and Technical Professions. Leonardo da Vinci Series: Good Practices.

    ERIC Educational Resources Information Center

    Commission of the European Communities, Brussels (Belgium). Directorate-General for Education and Culture.

    This document profiles programs for women in technical professions that are offered through the European Commission's Leonardo da Vinci program. The following programs are profiled: (1) Artemis and Diana (vocational guidance programs to help direct girls toward technology-related careers); (2) CEEWIT (an Internet-based information and…

  18. 40 CFR 60.45Da - Standard for mercury (Hg).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for mercury (Hg). 60.45Da... for mercury (Hg). (a) For each coal-fired electric utility steam generating unit other than an IGCC... gases that contain mercury (Hg) emissions in excess of each Hg emissions limit in paragraphs...

  19. 40 CFR 60.45Da - Standard for mercury (Hg).

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standard for mercury (Hg). 60.45Da... for mercury (Hg). (a) For each coal-fired electric utility steam generating unit other than an IGCC... gases that contain mercury (Hg) emissions in excess of each Hg emissions limit in paragraphs...

  20. Modelagem do vento e da fotosfera de AG Carinae

    NASA Astrophysics Data System (ADS)

    Groh, J. H.; Damineli, A.

    2003-08-01

    A trajetória evolutiva das estrelas de alta massa depende fortemente de suas taxas de perda de massa. Apesar do rápido progresso no estudo destas estrelas, a taxa de perda de massa e outros parâmetros físicos básicos, como a temperatura superficial e a velocidade terminal do vento ainda não estão bem determinados. Isto ocorre devido à presença de ventos irregulares, rápidos e fortes ao redor destas estrelas, tornando a interpretação dos seus espectros uma tarefa difícil. Assim, a modelagem do vento e da fotosfera dessas estrelas está sendo cada vez mais usada para obter tais parâmetros a partir dos espectros. O aumento da taxa de perda de massa durante a fase LBV (Variáveis Luminosas Azuis), comparado com outros tipos de estrelas, tem sido atribuído a instabilidades do tipo S Doradus. Dispomos de uma base de dados espectroscópicos cobrindo 22 anos de observações de AG Carinae, incluindo um ciclo S Doradus completo, com espectros CCD em alta resolução na faixa óptica e infravermelha. Utilizamos o programa desenvolvido por Schmutz (1997) para uma análise preliminar desse ciclo, obtendo a taxa de perda de massa a partir da linha do Ha. Não existe uma correlação clara da taxa de perda de massa com mudanças da temperatura efetiva, do raio da estrela e do fluxo na banda V. A estrela atingiu seu mínimo fotométrico (raio mínimo) em 1990 e o máximo fotométrico (raio máximo) em 1995, enquanto que o fluxo máximo da linha do Ha ocorreu em 1996. Além disso a taxa de perda de massa não segue esse ciclo, contrariamente às idéias correntes. Para fazer um modelo mais realista estamos usando o programa CMFGEN (Hillier & Miller), que trata a fotosfera e o vento estelar de forma consistente, considerando a radiação fora do equilíbrio termodinâmico (NLTE) e com blanketting total de linhas. Simulamos o espectro de AG Carinae em duas épocas extremas do ciclo S Dor para testar os resultados obtidos com o modelo mais simplificado.

  1. 49 CFR 178.58 - Specification 4DA welded steel cylinders for aircraft use.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 3 2014-10-01 2014-10-01 false Specification 4DA welded steel cylinders for...) SPECIFICATIONS FOR PACKAGINGS Specifications for Cylinders § 178.58 Specification 4DA welded steel cylinders for aircraft use. (a) Type, size, and service pressure. A DOT 4DA is a welded steel sphere (two...

  2. 49 CFR 178.58 - Specification 4DA welded steel cylinders for aircraft use.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 3 2012-10-01 2012-10-01 false Specification 4DA welded steel cylinders for...) SPECIFICATIONS FOR PACKAGINGS Specifications for Cylinders § 178.58 Specification 4DA welded steel cylinders for aircraft use. (a) Type, size, and service pressure. A DOT 4DA is a welded steel sphere (two...

  3. 49 CFR 178.58 - Specification 4DA welded steel cylinders for aircraft use.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 3 2013-10-01 2013-10-01 false Specification 4DA welded steel cylinders for...) SPECIFICATIONS FOR PACKAGINGS Specifications for Cylinders § 178.58 Specification 4DA welded steel cylinders for aircraft use. (a) Type, size, and service pressure. A DOT 4DA is a welded steel sphere (two...

  4. 49 CFR 178.58 - Specification 4DA welded steel cylinders for aircraft use.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 3 2011-10-01 2011-10-01 false Specification 4DA welded steel cylinders for...) SPECIFICATIONS FOR PACKAGINGS Specifications for Cylinders § 178.58 Specification 4DA welded steel cylinders for aircraft use. (a) Type, size, and service pressure. A DOT 4DA is a welded steel sphere (two...

  5. PanDaTox: A tool for accelerated metabolic engineering

    SciTech Connect

    Amitai, Gil; Sorek, Rotem

    2012-07-18

    Metabolic engineering is often facilitated by cloning of genes encoding enzymes from various heterologous organisms into E. coli. Such engineering efforts are frequently hampered by foreign genes that are toxic to the E. coli host. We have developed PanDaTox (www.weizmann.ac.il/pandatox), a web-based resource that provides experimental toxicity information for more than 1.5 million genes from hundreds of different microbial genomes. The toxicity predictions, which were extensively experimentally verified, are based on serial cloning of genes into E. coli as part of the Sanger whole genome shotgun sequencing process. PanDaTox can accelerate metabolic engineering projects by allowing researchers to exclude toxic genes from the engineering plan and verify the clonability of selected genes before the actual metabolic engineering experiments are conducted.

  6. A novel 29-kDa chicken heat shock protein.

    PubMed

    Einat, M F; Haberfeld, A; Shamay, A; Horev, G; Hurwitz, S; Yahav, S

    1996-12-01

    The family of small heat shock proteins is the more variable among the highly conserved superfamily of heat shock proteins (HSP). Using a metabolic labeling procedure with tissue explants, we have detected in chickens a new member of the small HSP family with an apparent molecular weight of 29-kDa. This protein was induced in broiler chickens' heart muscle and lungs following an in vivo heat stress. The 29-kDa band appears after 3 h of heat stress, much later than the induction of HSP 90, HSP 70, and HSP 27. The late onset of induction suggests that HSP 29 plays a more specific role of a "second stage defense protein".

  7. TA-DA: A TOOL FOR ASTROPHYSICAL DATA ANALYSIS

    SciTech Connect

    Da Rio, Nicola; Robberto, Massimo

    2012-12-01

    We present the Tool for Astrophysical Data Analysis (TA-DA), a new software aimed to greatly simplify and improve the analysis of stellar photometric data in comparison with theoretical models, and allow the derivation of stellar parameters from multi-band photometry. Its flexibility allows one to address a number of such problems: from the interpolation of stellar models, or sets of stellar physical parameters in general, to the computation of synthetic photometry in arbitrary filters or units; from the analysis of observed color-magnitude diagrams to a Bayesian derivation of stellar parameters (and extinction) based on multi-band data. TA-DA is available as a pre-compiled Interactive Data Language widget-based application; its graphical user interface makes it considerably user-friendly. In this paper, we describe the software and its functionalities.

  8. DaVinci's Mona Lisa entering the next dimension.

    PubMed

    Carbon, Claus-Christian; Hesslinger, Vera M

    2013-01-01

    For several of Leonardo da Vinci's paintings, such as The Virgin and Child with St Anne or the Mona Lisa, there exist copies produced by his own studio. In case of the Mona Lisa, a quite exceptional, rediscovered studio copy was presented to the public in 2012 by the Prado Museum in Madrid. Not only does it mirror its famous counterpart superficially; it also features the very same corrections to the lower layers, which indicates that da Vinci and the 'copyist' must have elaborated their panels simultaneously. On the basis of subjective (thirty-two participants estimated painter-model constellations) as well as objective data (analysis of trajectories between landmarks of both paintings), we revealed that both versions differ slightly in perspective. We reconstructed the original studio setting and found evidence that the disparity between both paintings mimics human binocular disparity. This points to the possibility that the two Giocondas together might represent the first stereoscopic image in world history.

  9. Calibration of Synthetic Photometry Using DA White Dwarfs

    NASA Astrophysics Data System (ADS)

    Holberg, J. B.; Bergeron, P.

    2005-12-01

    We have calibrated four major ground-based photometric systems with respect to the Hubble Space Telescope absolute flux scale, which is defined by Vega and four fundamental DA white dwarfs. These photometric systems include the Johnson-Kron-Cousins UBVRI, the Stromgren uvby filters, the 2MASS JHKs and the Sloan Digital Sky Survey ugriz filters. Synthetic magnitudes are calculated from model white dwarf spectra folded through the published filter response functions, these magnitudes in turn are absolutely calibrated with respect to the HST flux scale. Effective zero magnitude fluxes and zero point offsets of each system are determined. In order to verify the external observational consistency as well as to demonstrate the applicability of these definitions, the synthetic magnitudes are compared with the respective observed magnitudes of larger sets of DA white dwarfs that have well determined effective temperatures and surface gravities and which span a wide range in both of these parameters.

  10. Da Vinci's codex and the anatomy of healthcare.

    PubMed

    Stephens-Borg, Keith

    2012-08-01

    We usually display a laid-back approach to medical jargon throughout our theatre work. The word 'perioperative' is built from the Greek word 'peri' (around) and the Latin 'operari' (to work). Latin and Greek became the prefixed language of choice for Leonardo da Vinci, and his research was pivotal in determining the way in which surgical procedures are documented. Ancient manuscripts aided the unfolding of the secrets of anatomy, and Leonardo revealed that art was the key in expressive detailed explanation.

  11. GEODSS Tracking Results on Asteroid 2012 DA14

    DTIC Science & Technology

    2013-06-12

    meteor until stony or metallic material remnants make it to the surface of the planet in which case they become meteorites . Theoretically, the...passing in close proximity to the planet are a daily manifestation. In fact within days of the 2012 DA14 transit of the planet a large meteorite entered...although meteorites approximately basketball size hit the Earth about once per day, and objects the size of an automobile reach us roughly on a weekly

  12. Improving Security in the ATLAS PanDA System

    NASA Astrophysics Data System (ADS)

    Caballero, J.; Maeno, T.; Nilsson, P.; Stewart, G.; Potekhin, M.; Wenaus, T.

    2011-12-01

    The security challenges faced by users of the grid are considerably different to those faced in previous environments. The adoption of pilot jobs systems by LHC experiments has mitigated many of the problems associated with the inhomogeneities found on the grid and has greatly improved job reliability; however, pilot jobs systems themselves must then address many security issues, including the execution of multiple users' code under a common 'grid' identity. In this paper we describe the improvements and evolution of the security model in the ATLAS PanDA (Production and Distributed Analysis) system. We describe the security in the PanDA server which is in place to ensure that only authorized members of the VO are allowed to submit work into the system and that jobs are properly audited and monitored. We discuss the security in place between the pilot code itself and the PanDA server, ensuring that only properly authenticated workload is delivered to the pilot for execution. When the code to be executed is from a 'normal' ATLAS user, as opposed to the production system or other privileged actor, then the pilot may use an EGEE developed identity switching tool called gLExec. This changes the grid proxy available to the job and also switches the UNIX user identity to protect the privileges of the pilot code proxy. We describe the problems in using this system and how they are overcome. Finally, we discuss security drills which have been run using PanDA and show how these improved our operational security procedures.

  13. DA-9801 promotes neurite outgrowth via ERK1/2-CREB pathway in PC12 cells.

    PubMed

    Won, Jong Hoon; Ahn, Kyong Hoon; Back, Moon Jung; Ha, Hae Chan; Jang, Ji Min; Kim, Ha Hyung; Choi, Sang-Zin; Son, Miwon; Kim, Dae Kyong

    2015-01-01

    In the present study, we examined the mechanisms underlying the effect of DA-9801 on neurite outgrowth. We found that DA-9801 elicits its effects via the mitogen-activated protein kinase (MEK) extracellular signal-regulated kinase (ERK)1/2-cAMP response element-binding protein (CREB) pathway. DA-9801, an extract from a mixture of Dioscorea japonica and Dioscorea nipponica, was reported to promote neurite outgrowth in PC12 cells. The effects of DA-9801 on cell viability and expression of neuronal markers were evaluated in PC12 cells. To investigate DA-9801 action, specific inhibitors targeting the ERK signaling cascade were used. No cytotoxicity was observed in PC12 cells at DA-9801 concentrations of less than 30 µg/mL. In the presence of nerve growth factor (NGF, 2 ng/mL), DA-9801 promoted neurite outgrowth and increased the relative mRNA levels of neurofilament-L (NF-L), a marker of neuronal differentiation. The Raf-1 inhibitor GW5074 and MEK inhibitor PD98059 significantly attenuated DA-9801-induced neurite outgrowth. Additionally, the MEK1 and MEK2 inhibitor SL327 significantly attenuated the increase in the percentage of neurite-bearing PC12 cells induced by DA-9801 treatment. Conversely, the selective p38 mitogen-activated protein kinase inhibitor SB203580 did not attenuate the DA-9801 treatment-induced increase in the percentage of neurite-bearing PC12 cells. DA-9801 enhanced the phosphorylation of ERK1/2 and CREB in PC12 cells incubated with and without NGF. Pretreatment with PD98059 blocked the DA-9801-induced phosphorylation of ERK1/2 and CREB. In conclusion, DA-9801 induces neurite outgrowth by affecting the ERK1/2-CREB signaling pathway. Insights into the mechanism underlying this effect of DA-9801 may suggest novel potential strategies for the treatment of peripheral neuropathy.

  14. OpenDA-NEMO framework for ocean data assimilation

    NASA Astrophysics Data System (ADS)

    van Velzen, Nils; Altaf, Muhammad Umer; Verlaan, Martin

    2016-05-01

    Data assimilation methods provide a means to handle the modeling errors and uncertainties in sophisticated ocean models. In this study, we have created an OpenDA-NEMO framework unlocking the data assimilation tools available in OpenDA for use with NEMO models. This includes data assimilation methods, automatic parallelization, and a recently implemented automatic localization algorithm that removes spurious correlations in the model based on uncertainties in the computed Kalman gain matrix. We have set up a twin experiment where we assimilate sea surface height (SSH) satellite measurements. From the experiments, we can conclude that the OpenDA-NEMO framework performs as expected and that the automatic localization significantly improves the performance of the data assimilation algorithm by successfully removing spurious correlations. Based on these results, it looks promising to extend the framework with new kinds of observations and work on improving the computational speed of the automatic localization technique such that it becomes feasible to include large number of observations.

  15. The ATLAS PanDA Pilot in Operation

    NASA Astrophysics Data System (ADS)

    Nilsson, P.; Caballero, J.; De, K.; Maeno, T.; Stradling, A.; Wenaus, T.; ATLAS Collaboration

    2011-12-01

    The Production and Distributed Analysis system (PanDA) [1-2] was designed to meet ATLAS [3] requirements for a data-driven workload management system capable of operating at LHC data processing scale. Submitted jobs are executed on worker nodes by pilot jobs sent to the grid sites by pilot factories. This paper provides an overview of the PanDA pilot [4] system and presents major features added in light of recent operational experience, including multi-job processing, advanced job recovery for jobs with output storage failures, gLExec [5-6] based identity switching from the generic pilot to the actual user, and other security measures. The PanDA system serves all ATLAS distributed processing and is the primary system for distributed analysis; it is currently used at over 100 sites worldwide. We analyze the performance of the pilot system in processing real LHC data on the OSG [7], EGI [8] and Nordugrid [9-10] infrastructures used by ATLAS, and describe plans for its evolution.

  16. Domain annotation of trimeric autotransporter adhesins—daTAA

    PubMed Central

    Szczesny, Pawel; Lupas, Andrei

    2008-01-01

    Motivation: Trimeric autotransporter adhesins (TAAs), such as Yersinia YadA, Neisseria NadA, Moraxella UspAs, Haemophilus Hia and Bartonella BadA, are important pathogenicity factors of proteobacteria. Their high sequence diversity and distinct mosaic-like structure lead to difficulties in the annotation of their sequences. These stem from the large number of short repeats, the presence of compositionally unusual coiled-coils, fuzzy domain boundaries and regions of seemingly low sequence complexity. Results: We have developed a workflow, named daTAA, for the accurate domain annotation of TAAs. Its core consists of manually curated alignments and of knowledge-based rules that enhance assignments made by sequence similarity. Compared to general domain annotation servers such as PFAM, daTAA captures more domains and provides more sensitive domain detection, as well as integrated and detailed coiled-coil assignments. Availability: The daTAA server is freely accessible at http://toolkit.tuebingen.mpg.de/dataa Contact: andrei.lupas@tuebingen.mpg.de Supplementary information: Supplementary data are available at Bioinformatics online. PMID:18397894

  17. Identification of an abundant 56 kDa protein implicated in food allergy as granule-bound starch synthase

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Rice, the staple food of South and East Asian counties, is considered to be hypoallergenic. However, several clinical studies have documented rice-induced allergy in sensitive patients. Rice proteins with molecular weights of 14-16 kDa, 26 kDa, 33 kDa and 56 kDa have been identified as allergens. Re...

  18. [The Arabic influence in the "Colóquios dos simples e drogas da India" of Garcia da Orta].

    PubMed

    Ricordel, Joëlle

    2015-09-01

    The "Colóquios dos simples e drogas he cousas medicinais de Índia" (Conversations on the simples, drugs and medicinal substances of India) (1563) of Garcia da Orta is a botanical and pharmacognosy book. The author is a Portuguese physician who studied in the Spanish universities and practiced medicine mainly in India. He studies in short chapters presented in the form of dialogues about sixty simples. Sources to which he refers are indicative of a "classical" training, but also the mark of a curious and open mind to different cultures. The Arabic sources are numerous and mainly concern the identification of substances by abundant synonyms of their names in foreign languages and different medicinal uses that may have been done by the ancient physicians. However, Da Orta is critical with respect to these sources, seeking contradictions and differences of opinion among authors. He confronts them with the oral information collected thanks to a wide network of contacts.

  19. Characterization of a dopamine receptor (DA sub 2K ) in the kidney inner medulla

    SciTech Connect

    Huo, T.; Ye, M.Q.; Healy, D.P. )

    1991-04-15

    Dopamine (DA) produces a natriuretic/diuretic response in the kidney by mechanisms that are still not well understood. There is some indication that DA{sub 2} receptors may be involved in mediating the effects of DA, but little is known regarding the nature of this receptor in the kidney. Autoradiographic localization of ({sup 3}H)spiperone, a DA{sub 2} antagonist, indicated that high-density binding was restricted to inner medullary collecting ducts (IMCDs). ({sup 3}H)Spiperone binding was saturable, high affinity and high density. Functionally, DA stimulated prostaglandin E{sub 2} production by IMCD cells, an effect that could be blocked by the DA{sub 2} antagonist domperidone. These results indicate that the kidney inner medulla expresses a functional DA receptor that may represent a newly identified DA receptor subtype (here designated DA{sub 2K}). Moreover, these results suggest that the kidney inner medulla may be a significant site at which DA, either directly or indirectly, influences water and electrolyte excretion.

  20. Reflecting on Culture. (Reflexionando Sobre la Cultura.)

    ERIC Educational Resources Information Center

    Irizarry, Estelle

    1980-01-01

    The article comments on two articles, previously published in the same journal, which address the relationship between the "little" cultural tradition of Chicanos, Cubans, and Puerto Ricans and the "great" tradition of Hispanic arts and letters. Notes similarities among these groups and calls for the banding together of…

  1. Culture and Illness (Cultura y Enfermedad)

    ERIC Educational Resources Information Center

    Martinez, Pedro Daniel

    1975-01-01

    Every culture has unique attitudes and values toward health and sickness. This article explores Mexican medical culture on native, folk and scientific levels, and its effect on national health and medical practice. (In Spanish). (CK)

  2. Leonardo da Vinci and the origin of semen

    PubMed Central

    Noble, Denis; DiFrancesco, Dario; Zancani, Diego

    2014-01-01

    It is well known that Leonardo da Vinci made several drawings of the human male anatomy. The early drawings (before 1500) were incorrect in identifying the origin of semen, where he followed accepted teaching of his time. It is widely thought that he did not correct this mistake, a view that is reflected in several biographies. In fact, he made a later drawing (after 1500) in which the description of the anatomy is remarkably accurate and must have been based on careful dissection. In addition to highlighting this fact, acknowledged previously in only one other source, this article reviews the background to Leonardo's knowledge of the relevant anatomy. PMID:27494016

  3. Visual tracking of da Vinci instruments for laparoscopic surgery

    NASA Astrophysics Data System (ADS)

    Speidel, S.; Kuhn, E.; Bodenstedt, S.; Röhl, S.; Kenngott, H.; Müller-Stich, B.; Dillmann, R.

    2014-03-01

    Intraoperative tracking of laparoscopic instruments is a prerequisite to realize further assistance functions. Since endoscopic images are always available, this sensor input can be used to localize the instruments without special devices or robot kinematics. In this paper, we present an image-based markerless 3D tracking of different da Vinci instruments in near real-time without an explicit model. The method is based on different visual cues to segment the instrument tip, calculates a tip point and uses a multiple object particle filter for tracking. The accuracy and robustness is evaluated with in vivo data.

  4. A quasi-passive CMOS pipeline D/A converter

    NASA Technical Reports Server (NTRS)

    Wang, Fong-Jim; Temes, Gabor C.; Law, Simon

    1989-01-01

    A novel pipeline digital-to-analog converter configuration, based on switched-capacitor techniques, is described. An n-bit D/A conversion can be implemented by cascading n + 1 unit cells. The device count of the circuit increases linearly, not exponentially, with the conversion accuracy. The new configuration can be pipelined. Hence, the conversion rate can be increased without requiring a higher clock rate. An experimental 10-bit DAC prototype has been fabricated using a 3-micron CMOS process. The results show that high-speed, high-accuracy, and low-power operation can be achieved without special process or postprocess trimming.

  5. Ultratight crystal packing of a 10 kDa protein

    SciTech Connect

    Trillo-Muyo, Sergio; Chruszcz, Maksymilian; Minor, Wladek; Kuisiene, Nomeda

    2013-03-01

    The crystal structure of the C-terminal domain of a putative U32 peptidase from G. thermoleovorans is reported; it is one of the most tightly packed protein structures reported to date. While small organic molecules generally crystallize forming tightly packed lattices with little solvent content, proteins form air-sensitive high-solvent-content crystals. Here, the crystallization and full structure analysis of a novel recombinant 10 kDa protein corresponding to the C-terminal domain of a putative U32 peptidase are reported. The orthorhombic crystal contained only 24.5% solvent and is therefore among the most tightly packed protein lattices ever reported.

  6. Leonardo da Vinci and Kethem-Kiveris vena.

    PubMed

    Dolezal, Antonín; Skorepova-Honzlova, Zita; Jelen, Karel

    2012-01-01

    In the drawing of coitus by Leonardo da Vinci are pictured the contemporary hypotheses regarding this act. The authors analyze the mamillaruteral connection depicted by the artist and grow up to believe that this is a hypothetical kiveris vena, female vein described by Anatomist Master Nicolai Physicus from the Salerno School. The Hebrew roots were found in the name. The connection is described also by Mondino in The Anathomia. The same connection can be found in the picture of the pregnant woman in Fasciculus Medicinæ by Johannes De Ketham.

  7. LEONARDO DA VINCI AND THE ORIGIN OF SEMEN.

    PubMed

    Noble, Denis; DiFrancesco, Dario; Zancani, Diego

    2014-12-20

    It is well known that Leonardo da Vinci made several drawings of the human male anatomy. The early drawings (before 1500) were incorrect in identifying the origin of semen, where he followed accepted teaching of his time. It is widely thought that he did not correct this mistake, a view that is reflected in several biographies. In fact, he made a later drawing (after 1500) in which the description of the anatomy is remarkably accurate and must have been based on careful dissection. In addition to highlighting this fact, acknowledged previously in only one other source, this article reviews the background to Leonardo's knowledge of the relevant anatomy.

  8. An improvement of LLNA:DA to assess the skin sensitization potential of chemicals.

    PubMed

    Zhang, Hongwei; Shi, Ying; Wang, Chao; Zhao, Kangfeng; Zhang, Shaoping; Wei, Lan; Dong, Li; Gu, Wen; Xu, Yongjun; Ruan, Hongjie; Zhi, Hong; Yang, Xiaoyan

    2017-01-01

    We developed a modified local lymph node assay based on ATP (LLNA:DA), termed the Two-Stage LLNA:DA, to further reduce the animal numbers in the identification of sensitizers. In the Two-Stage LLNA:DA procedure, 13 chemicals ranging from non-sensitizers to extreme sensitizers were selected. The first stage used reduced LLNA:DA (rLLNA:DA) to screen out sensitive chemicals. The second stage used LLNA:DA based on OECD 442 (A) to classify those potential sensitizers screened out in the first stage. In the first stage, the SIs of the methyl methacrylate, salicylic acid, methyl salicylate, ethyl salicylate, isopropanol and propanediol were below 1.8 and need not to be tested in the second step. Others continued to be tested by LLNA:DA. In the second stage, sodium lauryl sulphate and xylene were classified as weak sensitizers. a-hexyl cinnamic aldehyde and eugenol were moderate sensitizers. Benzalkonium chloride and glyoxal were strong sensitizers, and phthalic anhydride was an extreme sensitizer. The 9/9, 11/12, 10/11, and 8/13 (positive or negative only) categories of the Two-Stage LLNA:DA were consistent with those from the other methods (LLNA, LLNA:DA, GPMT/BT and HMT/HPTA), suggesting that Two-Stage LLNA:DA have a high coincidence rate with reported data. In conclusion, The Two-Stage LLNA:DA is in line with the "3R" rules, and can be a modification of LLNA:DA but needs more study.

  9. Purification, characterization and gene cloning of Da-36, a novel serine protease from Deinagkistrodon acutus venom.

    PubMed

    Zheng, Ying; Ye, Feng-Ping; Wang, Jie; Liao, Guo-Yang; Zhang, Yun; Fan, Quan-Shui; Lee, Wen-Hui

    2013-06-01

    A serine protease termed Da-36 was isolated from crude venom of Deinagkistrodon acutus. The enzyme was a single chain protein with an apparent molecular weight of 36,000 on SDS-PAGE with an isoelectric point of 6.59. Da-36 could clot human plasma by cleaving the Aα, Bβ and γ chains of fibrinogen and also exhibited arginine esterase activity. The proteolytic activity of Da-36 toward TAME was strongly inhibited by PMSF and moderately affected by benzamidine and aprotinin, indicating that it was a serine protease. Meanwhile, Da-36 showed stability with wide temperature (20-50 °C) and pH value ranges (pH 6-10). Divalent metal ions of Ca(2+), Mg(2+), and Mn(2+) had no effects but Zn(2+) and Cu(2+) inhibited the arginine esterase activity of Da-36. Total DNA was extracted directly from the lyophilized crude venom and the gene (5.5 kbp) coding for Da-36 had been successfully cloned. Sequence analysis revealed that the Da-36 gene contained five exons and four introns. The mature Da-36 was encoded by four separate exons. The deduced mature amino acid sequence of Da-36 was in good agreement with the determined N-terminal sequence of the purified protein and shared high homology with other serine proteases isolated from different snake venoms. Blast search using amino acid sequence of Da-36 against public database revealed that Da-36 showed a maximal identity of 90% with both Dav-X (Swiss-Prot: Q9I8W9.1) and thrombin-like protein 1 (GenBank: AAW56608.1) from the same snake species, indicating that Da-36 is a novel serine protease.

  10. Identification of Methylated Deoxyadenosines in Genomic DNA by dA6m DNA Immunoprecipitation

    PubMed Central

    Koziol, Magdalena J.; Bradshaw, Charles R.; Allen, George E.; Costa, Ana S.H.; Frezza, Christian

    2017-01-01

    dA6m DNA immunoprecipitation followed by deep sequencing (DIP-Seq) is a key tool in identifying and studying the genome-wide distribution of N6-methyldeoxyadenosine (dA6m). The precise function of this novel DNA modification remains to be fully elucidated, but it is known to be absent from transcriptional start sites and excluded from exons, suggesting a role in transcriptional regulation (Koziol et al., 2015). Importantly, its existence suggests that DNA might be more diverse than previously believed, as further DNA modifications might exist in eukaryotic DNA (Koziol et al., 2015). This protocol describes the method to perform dA6m DNA immunoprecipitation (DIP), as was applied to characterize the first dA6m methylome analysis in higher eukaryotes (Koziol et al., 2015). In this protocol, we describe how genomic DNA is isolated, fragmented and then DNA containing dA6m is pulled down with an antibody that recognizes dA6m in genomic DNA. After subsequent washes, DNA fragments that do not contain dA6m are eliminated, and the dA6m containing fragments are eluted from the antibody in order to be processed further for subsequent analyses. Background This protocol was developed in order to identify regions in the genome that contain dA6m. It can be used to detect dA6m in different genomes. As a guideline, this protocol was established from existing approaches used to detect adenosine methylation in RNA (Dominissini et al., 2013). We developed this protocol and adapted it for the detection of dA6m in DNA, rather than detecting adenosine methylation RNA. This was required, as no protocol was available at that time to allow the genome-wide identification of dA6m in eukaryotic DNA. PMID:28180135

  11. Effects of DA-Phen, a dopamine-aminoacidic conjugate, on alcohol intake and forced abstinence.

    PubMed

    Sutera, Flavia Maria; De Caro, Viviana; Cannizzaro, Carla; Giannola, Libero Italo; Lavanco, Gianluca; Plescia, Fulvio

    2016-09-01

    The mesolimbic dopamine (DA) system plays a key role in drug reinforcement and is involved in the development of alcohol addiction. Manipulation of the DAergic system represents a promising strategy to control drug-seeking behavior. Previous studies on 2-amino-N-[2-(3,4-dihydroxy-phenyl)-ethyl]-3-phenyl-propionamide (DA-Phen) showed in vivo effects as a DA-ergic modulator. This study was aimed at investigate DA-Phen effects on operant behavior for alcohol seeking behavior, during reinstatement following subsequent periods of alcohol deprivation. For this purpose, male Wistar rats were tested in an operant paradigm of self-administration; behavioral reactivity and anxiety like-behavior during acute abstinence were evaluated. A characterization of DA-Phen CNS targeting by its quantification in the brain was also carried out. Our findings showed that DA-Phen administration was able to reduce relapse in alcohol drinking by 50% and reversed the alterations in behavioral reactivity and emotionality observed during acute abstinence. In conclusion, DA-Phen can reduce reinstatement of alcohol drinking in an operant-drinking paradigm following deprivation periods and reverse abstinence-induced behavioral phenotype. DA-Phen activity seems to be mediated by the modulation of the DAergic transmission. However further studies are needed to characterize DA-Phen pharmacodynamic and pharmacokinetic properties, and its potential therapeutic profile in alcohol addiction.

  12. A 45-kDa acetylcholinesterase protoxin of Aeromonas hydrophila: purification and immunogenicity in fish.

    PubMed

    Pérez, M J; Rodríguez, L A; Fernández-Briera, A; Nieto, T P

    2002-05-21

    A rabbit antiserum to the 15-kDa acetylcholinesterase toxin neutralised the lethal effect of the 15-kDa toxin of Aeromonas hydrophila when injected into trout. However, immunisation of fish with the 15-kDa toxoid failed to induce an antibody response, and a higher molecular mass form of this toxin was purified from the extracellular products with the aim of inducing an immune response in fish. The optimal conditions for production of extracellular products by A. hydrophila strain B32 were studied to increase the concentration of this protoxin. The extracellular products were fractionated by molecular exclusion chromatography to yield a purified protoxin with an estimated molecular mass of 45 kDa by SDS-PAGE and which gave a positive reaction in Western blotting with the rabbit anti-15-kDa toxin serum. Since the 45-kDa protoxin showed lower specific acetylcholinesterase activity than the active 15-kDa toxin, the behaviour of the active site was studied using specific inhibitors. This 45-kDa protoxin was 13.3-fold less toxic than the 15-kDa toxin and induced antibody production in fish.

  13. PX-52, A novel inhibitor of 14 kDa secretory and 85 kDa cytosolic phospholipases A2.

    PubMed

    Franson, R C; Rosenthal, M D

    1997-01-01

    Previously we reported that PGBx, a prostaglandin oligomer with anti-inflammatory activity, inhibited 14 kDa phospholipase A2 (PLA2) activity and blocked arachidonic acid mobilization in prelabeled human neutrophils (Biochim. Biophys. Acta 1006:272-277, 278-286, 1989) This study describes a new inhibitor of phospholipase A2, PX-52, that also blocks agonist induced arachidonic acid mobilization in prelabeled cells. PX-52, a fatty acid polymer, inhibited hydrolysis of 14C-oleate labeled E.coli by a variety of 14 kDa PLA2s including human PMN, sperm, synovial fluid and disc, as well as porcine pancreas, N. naja, and bee venom in a dose-dependent manner with IC50s ranging from 1.0-3.7 uM. Inhibition of activity was comparable at different Ca2+ concentrations, but was relieved by increasing substrate concentration or by methylation of PX-52. Hydrolysis of [14C]-arachidonyl phosphatidylcholine by 85 kDa, cytosolic PLA2 from U937 cells was similarly inhibited by PX-52, the IC50 = 5 uM. Arachidonic acid mobilization induced by A23187 in prelabeled human PMNs was blocked by PX-52; IC50 = 10-15 uM while concentrations of up to 80 uM oleate had no effect. These results demonstrate that PX-52 inhibits the in vitro activity of secretory and cytosolic PLA2s and agonist-induced arachidonic acid release from human cells. Given its ability to block the arachidonic acid cascade, PX-52 may be useful in the control of inflammation.

  14. Chandra Confirmation of a Pulsar Wind Nebula in DA 495

    NASA Technical Reports Server (NTRS)

    Arzoumanian, Z.; Safi-Harb, S.; Landecker, T.L.; Kothes, R.; Camilo, F.

    2008-01-01

    As part of a multiwavelength study of the unusual radio supernova remnant DA 495, we present observations made with the Chandra X-ray Observatory. Imaging and spectroscopic analysis confirms the previously detected X-ray source at the heart of the annular radio nebula, establishing the radiative properties of two key emission components: a soft unresolved source with a blackbody temperature of 1 MK consistent with a neutron star, surrounded by a nontherma1 nebula 40" in diameter exhibiting a power-law spectrum with photon index Gamma = 1.63, typical of a pulsar wind nebula. Morphologically, the nebula appears to be slightly extended along a direction, in projection on the sky, previously demonstrated to be of significance in radio and ASCA observations; we argue that this represents the orientation of the pulsar spin axis. At smaller scales, a narrow X-ray feature is seen extending out 5" from the point source, but energetic arguments suggest that it is not the resolved termination shock of the pulsar wind against the ambient medium. Finally, we argue based on synchrotron lifetimes in the nebular magnetic field that DA 495 represents the first example of a pulsar wind nebula in which electromagnetic flux makes up a significant part, together with particle flux, of the neutron star's wind.

  15. Calibration of Synthetic Photometry Using DA White Dwarfs

    NASA Astrophysics Data System (ADS)

    Holberg, J. B.; Bergeron, Pierre

    2006-09-01

    We have calibrated four major ground-based photometric systems with respect to the Hubble Space Telescope (HST) absolute flux scale, which is defined by Vega and four fundamental DA white dwarfs. These photometric systems include the Johnson-Kron-Cousins UBVRI, the Strömgren uvby filters, the Two Micron All Sky Survey JHKs, and the Sloan Digital Sky Survey ugriz filters. Synthetic magnitudes are calculated from model white dwarf spectra folded through the published filter response functions; these magnitudes in turn are absolutely calibrated with respect to the HST flux scale. Effective zero-magnitude fluxes and zero-point offsets of each system are determined. In order to verify the external observational consistency, as well as to demonstrate the applicability of these definitions, the synthetic magnitudes are compared with the respective observed magnitudes of larger sets of DA white dwarfs that have well-determined effective temperatures and surface gravities and span a wide range in both of these parameters.

  16. D-A and D-2 dopamine receptor function in the rabbit retina: a model for the central nervous system

    SciTech Connect

    Hensler, J.G.

    1987-01-01

    Studies were done investigating the effect of the synaptic concentration of the transmitter DA, modified by changes in the frequency of electrical field stimulation and by the DA uptake inhibitor nomifensine, on the modulation of /sup 3/H-DA release by D-2 DA autoreceptors and by melatonin receptor sites. At lower synaptic concentrations of the transmitter dopamine, D-2 DA receptor agonists were more potent, while antagonists were more potent when the synaptic concentration of transmitter was higher. The potency of melatonin to inhibit DA release was not altered by the frequency of field stimulation of by frequency-dependent changes in the synaptic concentration of the transmitter.

  17. Immunoreactivity of the Mycobacterium avium subsp. paratuberculosis 19-kDa lipoprotein

    PubMed Central

    Huntley, Jason FJ; Stabel, Judith R; Bannantine, John P

    2005-01-01

    Background The Mycobacterium tuberculosis 19-kDa lipoprotein has been reported to stimulate both T and B cell responses as well as induce a number of Th1 cytokines. In order to evaluate the Mycobacterium avium subsp. paratuberculosis (M. avium subsp. paratuberculosis) 19-kDa lipoprotein as an immunomodulator in cattle with Johne's disease, the gene encoding the 19-kDa protein (MAP0261c) was analyzed. Results MAP0261c is conserved in mycobacteria, showing a 95% amino acid identity in M. avium subspecies avium, 84% in M. intracellulare and 76% in M. bovis and M. tuberculosis. MAP0261c was cloned, expressed, and purified as a fusion protein with the maltose-binding protein (MBP-19 kDa) in Escherichia coli. IFN-γ production was measured from 21 naturally infected and 9 control cattle after peripheral blood mononuclear cells (PBMCs) were stimulated with a whole cell lysate (WCL) of M. avium subsp. paratuberculosis or the recombinant MBP-19 kDa. Overall, the mean response to MBP-19 kDa was not as strong as the mean response to the WCL. By comparison, cells from control, non-infected cattle did not produce IFN-γ after stimulation with either WCL or MBP-19 kDa. To assess the humoral immune response to the 19-kDa protein, sera from cattle with clinical Johne's disease were used in immunoblot analysis. Reactivity to MBP-19 kDa protein, but not MBP alone, was observed in 9 of 14 infected cattle. Antibodies to the 19-kDa protein were not observed in 8 of 9 control cows. Conclusions Collectively, these results demonstrate that while the 19-kDa protein from M. avium subsp. paratuberculosis stimulates a humoral immune response and weak IFN-γ production in infected cattle, the elicited responses are not strong enough to be used in a sensitive diagnostic assay. PMID:15663791

  18. The 37kDa/67kDa Laminin Receptor acts as a receptor for Aβ42 internalization

    PubMed Central

    Da Costa Dias, Bianca; Jovanovic, Katarina; Gonsalves, Danielle; Moodley, Kiashanee; Reusch, Uwe; Knackmuss, Stefan; Weinberg, Marc S.; Little, Melvyn; Weiss, Stefan F. T.

    2014-01-01

    Neuronal loss is a major neuropathological hallmark of Alzheimer's disease (AD). The associations between soluble Aβ oligomers and cellular components cause this neurotoxicity. The 37 kDa/67 kDa laminin receptor (LRP/LR) has recently been implicated in Aβ pathogenesis. In this study the mechanism underlying the pathological role of LRP/LR was elucidated. Försters Resonance Energy Transfer (FRET) revealed that LRP/LR and Aβ form a biologically relevant interaction. The ability of LRP/LR to form stable associations with endogenously shed Aβ was confirmed by pull down assays and Aβ-ELISAs. Antibody blockade of this association significantly lowered Aβ42 induced apoptosis. Furthermore, antibody blockade and shRNA mediated downregulation of LRP/LR significantly hampered Aβ42 internalization. These results suggest that LRP/LR is a receptor for Aβ42 internalization, mediating its endocytosis and contributing to the cytotoxicity of the neuropeptide by facilitating intra-cellular Aβ42 accumulation. These findings recommend anti-LRP/LR specific antibodies and shRNAs as potential therapeutic tools for AD treatment. PMID:24990253

  19. Foxa2 acts as a co-activator potentiating expression of the Nurr1-induced DA phenotype via epigenetic regulation.

    PubMed

    Yi, Sang-Hoon; He, Xi-Biao; Rhee, Yong-Hee; Park, Chang-Hwan; Takizawa, Takumi; Nakashima, Kinichi; Lee, Sang-Hun

    2014-02-01

    Understanding how dopamine (DA) phenotypes are acquired in midbrain DA (mDA) neuron development is important for bioassays and cell replacement therapy for mDA neuron-associated disorders. Here, we demonstrate a feed-forward mechanism of mDA neuron development involving Nurr1 and Foxa2. Nurr1 acts as a transcription factor for DA phenotype gene expression. However, Nurr1-mediated DA gene expression was inactivated by forming a protein complex with CoREST, and then recruiting histone deacetylase 1 (Hdac1), an enzyme catalyzing histone deacetylation, to DA gene promoters. Co-expression of Nurr1 and Foxa2 was established in mDA neuron precursor cells by a positive cross-regulatory loop. In the presence of Foxa2, the Nurr1-CoREST interaction was diminished (by competitive formation of the Nurr1-Foxa2 activator complex), and CoREST-Hdac1 proteins were less enriched in DA gene promoters. Consequently, histone 3 acetylation (H3Ac), which is responsible for open chromatin structures, was strikingly increased at DA phenotype gene promoters. These data establish the interplay of Nurr1 and Foxa2 as the crucial determinant for DA phenotype acquisition during mDA neuron development.

  20. 40 CFR 60.44Da - Standard for nitrogen oxides (NOX).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standard for nitrogen oxides (NOX). 60.44Da Section 60.44Da Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS... for nitrogen oxides (NOX). (a) On and after the date on which the initial performance test...

  1. 76 FR 37684 - Airworthiness Directives; Diamond Aircraft Industries GmbH Model (Diamond) DA 40 Airplanes...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-28

    ... Federal Aviation Administration 14 CFR Part 39 RIN 2120-AA64 Airworthiness Directives; Diamond Aircraft Industries GmbH Model (Diamond) DA 40 Airplanes Equipped With Certain Cabin Air Conditioning Systems AGENCY... inspections of the Diamond Model DA 40 airplanes equipped with a VCS installed per Premier Aircraft...

  2. 76 FR 19903 - Special Conditions: Diamond Aircraft Industry Model DA-40NG; Diesel Cycle Engine

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-11

    ... Conditions: Diamond Aircraft Industry Model DA-40NG; Diesel Cycle Engine AGENCY: Federal Aviation... conditions are issued for the Diamond Aircraft Industry (DAI) GmbH model DA-40NG the Austro Engine GmbH model... the postcard and mail it back to you. Background On May 11, 2010 Diamond Aircraft Industry...

  3. The Indicative and Subjunctive "da"-complements in Serbian A Syntactic-Semantic Approach

    ERIC Educational Resources Information Center

    Todorovic, Natasa

    2012-01-01

    A syntactic-semantic investigation of subjunctive and indicative "da"-complements in Serbian is conducted in this project. After a careful comparison of Serbian sentence constructions with "da"-complements to the equivalent sentence structures in languages of the Balkans as well as other Slavic languages, it is clearly…

  4. Tuning PEG-DA hydrogel properties via solvent-induced phase separation (SIPS)†

    PubMed Central

    Bailey, Brennan Margaret; Hui, Vivian; Fei, Ruochong

    2012-01-01

    Poly(ethylene glycol) diacrylate (PEG-DA) hydrogels are widely utilized to probe cell-material interactions and ultimately for a material-guided approach to tissue regeneration. In this study, PEG-DA hydrogels were fabricated via solvent-induced phase separation (SIPS) to obtain hydrogels with a broader range of tunable physical properties including morphology (e.g. porosity), swelling and modulus (G′). In contrast to conventional PEG-DA hydrogels prepared from an aqueous precursor solution, the reported SIPS protocol utilized a dichloromethane (DCM) precursor solution which was sequentially photopolymerized, dried and hydrated. Physical properties were further tailored by varying the PEG-DA wt% concentration (5 wt%–25 wt%) and Mn (3.4k and 6k g mol −1). SIPS produced PEG-DA hydrogels with a macroporous morphology as well as increased G′ values versus the corresponding conventional PEG-DA hydrogels. Notably, since the total swelling was not significantly changed versus the corresponding conventional PEG-DA hydrogels, pairs or series of hydrogels represent scaffolds in which morphology and hydration or G′ and hydration are uncoupled. In addition, PEG-DA hydrogels prepared via SIPS exhibited enhanced degradation rates. PMID:22956857

  5. Augmenting Effect of DA-9601 on Ghrelin in an Acute Gastric Injury Model

    PubMed Central

    Baek, Yoo Hum; Lee, Kang Nyeong; Jun, Dae Won; Yoon, Byung Chul; Kim, Ju Mi; Oh, Tae Young

    2011-01-01

    Background/Aims Acute gastric injury by alcohol or indomethacin has been reported to be prevented by DA-9601, an extract of the herb Artemisia asiatica. Ghrelin, an endogenously produced gastrointestinal peptide hormone, has also been demonstrated to play a role in gastric mucosal defense. The aim of this study was to investigate the effects of DA-9601 on ghrelin in an acute gastric injury model induced by alcohol or indomethacin. Methods A total of 140 Sprague-Dawley rats were divided into two groups, a placebo group and a DA-9601-pretreated group. Thirty minutes later, half of the rats in each group received ethanol injury and the other half received indomethacin injury. Levels of serum ghrelin and gastric mucosal ghrelin mRNA were measured by ELISA and RT-PCR, respectively. Results Immediately after ethanol administration, ghrelin increased in both groups pretreated with DA-9601 and placebo. However, the increase occurred more rapidly and was higher in the DA-9601-pretreated rats than in the controls that did not receive DA-9601-pretreatment. Similarly, from 30 minutes to 2 hours after indomethacin administration, the DA-9601-pretreated rats showed a significant increase in serum and gastric mucosal ghrelin concentrations, whereas placebo-pretreated rats showed only a mild increase. Conclusions DA-9601 potentiates the endogenous production and secretion of ghrelin in acute gastric injury models induced by ethanol or indomethacin. PMID:21461072

  6. A Creative Approach to the Common Core Standards: The Da Vinci Curriculum

    ERIC Educational Resources Information Center

    Chaucer, Harry

    2012-01-01

    "A Creative Approach to the Common Core Standards: The Da Vinci Curriculum" challenges educators to design programs that boldly embrace the Common Core State Standards by imaginatively drawing from the genius of great men and women such as Leonardo da Vinci. A central figure in the High Renaissance, Leonardo made extraordinary contributions as a…

  7. Paśu Ayurvĕda (veterinary medicine) in Garudapurăņa.

    PubMed

    Varanasi, Subhose; Narayana, A

    2007-01-01

    The history of veterinary medicine is closely tied to the development of human medicine. Evidence of animal medicine has been found in ancient civilizations, such as those of the Hindu, Babylonians, Hebrews, Arabs, Greeks, and Romans. Ancient Indian literature in the form of the holy Vĕda, Purăna, Brăhmaņa, epics, etc. is flooded with information on animal care. The Purăņa are ancient scriptures discuss varied topics like devotion to God and his various aspects, traditional sciences like Ayurvĕda, Jyŏtişa (Astrology), cosmology, concepts like dharma, karma, reincarnation and many others. The treatment of animal diseases using Ayurvedic medicine has been mentioned in Garudapurăna, Agnipurăņa, Atri-samhită, Matsyapurăņa and many other texts. The Garudapurăņa is one of the important Săttvika purăna, the subject matter is divided into two parts, viz. Pŭrvakhaņda (first part) and an Uttarakhaņda (subsequent part). Gavăyurvĕda, Gajăyurvĕda narrated briefly and Aśvăyurvĕda described detailly in Pŭrvakhaņda.

  8. 32 CFR Appendix F to Part 623 - Power of Attorney (DA Form 4881-4-R)

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 3 2010-07-01 2010-07-01 true Power of Attorney (DA Form 4881-4-R) F Appendix F to Part 623 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY SUPPLIES AND EQUIPMENT LOAN OF ARMY MATERIEL Pt. 623, App. F Appendix F to Part 623—Power of Attorney (DA Form...

  9. 32 CFR Appendix F to Part 623 - Power of Attorney (DA Form 4881-4-R)

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 3 2011-07-01 2009-07-01 true Power of Attorney (DA Form 4881-4-R) F Appendix F to Part 623 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY SUPPLIES AND EQUIPMENT LOAN OF ARMY MATERIEL Pt. 623, App. F Appendix F to Part 623—Power of Attorney (DA Form...

  10. 32 CFR Appendix E to Part 623 - Surety Bond (DA Form 4881-3-R)

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 3 2010-07-01 2010-07-01 true Surety Bond (DA Form 4881-3-R) E Appendix E to Part 623 National Defense Department of Defense (Continued) DEPARTMENT OF THE ARMY SUPPLIES AND EQUIPMENT LOAN OF ARMY MATERIEL Pt. 623, App. E Appendix E to Part 623—Surety Bond (DA Form...

  11. Tyrosine phosphorylation of two cytosolic proteins of 50 kDa and 35 kDa in rat liver by insulin-receptor kinase in vitro.

    PubMed Central

    Kwok, Y C; Yip, C C

    1987-01-01

    Insulin-receptor tyrosine kinase can phosphorylate a variety of artificial substrates in vitro. Its physiological substrate(s), however, remains unknown. In the present study, we show that immobilized insulin receptors phosphorylate tyrosine residues of two cytosolic proteins of 50 kDa and 35 kDa in rat liver. Phosphorylation of these two proteins required Mn2+- or Mg2+-ATP as the phosphate donor. Phosphorylation was time- and temperature-dependent. Furthermore, the rate of phosphorylation of the two proteins was related to the autophosphorylated state of the insulin receptor. The pI of the phosphorylated 50 kDa and 35 kDa proteins was 5.4 and 5.6 respectively. These proteins were present in low abundance. They were not related to each other, nor to the insulin receptor, as demonstrated by in-gel proteolytic digestion and by immunoprecipitation using antibodies produced against them. They were specific substrates for the insulin receptor kinase, since they were not phosphorylated by epidermal-growth-factor-receptor kinase. These observations suggest that the 50 kDa and 35 kDa cytosolic proteins may be endogenous substrates for the insulin-receptor kinase. Images Fig. 1. Fig. 2. Fig. 5. Fig. 6. Fig. 7. Fig. 8. Fig. 9. PMID:2829823

  12. The 10 kDa protein of Taenia solium metacestodes shows genus specific antigenicity.

    PubMed

    Park, S K; Yun, D H; Chung, J Y; Kong, Y; Cho, S Y

    2000-09-01

    Genus specific antigenicity of the 10 kDa protein in cyst fluid (CF) of Taenia solium metacestodes was demonstrated by comparative immunoblot analysis. When CFs from taeniid metacestodes of T. saginata, T. solium, T. taeniaeformis and T. crassiceps were probed with specific monoclonal antibody (mAb) raised against 150 kDa protein of T. solium metacestodes, specific antibody reactions were observed in 7 and 10 kDa proteins of T. solium and in 7/8 kDa of T. saginata, T. taeniaeformis and T. crassiceps. The mAb did not react with any protein in hydatid fluid of Echinococcus granulosus and E. multilocularis. This result revealed that the 10 kDa peptide of T. solium metacestodes and its equivalent proteins of different Taenia metacestodes are genus specific antigens that are shared among different Taenia species.

  13. Growth-Promoting Hormone DA-6 Assists Phytoextraction and Detoxification of Cd by Ryegrass.

    PubMed

    He, Shanying; Wu, Qiuling; He, Zhenli

    2015-01-01

    A pot experiment was carried out to study the effect of growth-promoting hormone diethyl aminoethyl hexanoate (DA-6) on Cd phytoextraction and detoxification in ryegrass. Foliar spray of DA-6 significantly enhanced Cd extraction efficiency (P<0.05), with 1 μM DA-6 the most effective. At the subcellular level, 43-53% of Cd was soluble fraction and 23-46% in cell wall, and 9-25% in organelles. Chemical speciation analysis showed that 52.7-58.5% of Cd was NaCl extractable, 12.1-22.7% ethanol extractable, followed by other fractions. DA-6 alleviated metal toxicity by fixing more Cd in cell wall and decreasing Cd migration in plant. In conclusion, ryegrass tolerates Cd by cell wall compartmentalization along with protein and organic acids combination, and the treatment of 1 μM DA-6 appears to be optimal for enhancing the remediation efficiency of ryegrass for Cd contaminated soil.

  14. DA-9701: A New Multi-Acting Drug for the Treatment of Functional Dyspepsia.

    PubMed

    Kwon, Yong Sam; Son, Miwon

    2013-05-30

    Motilitone(®) (DA-9701) is a new herbal drug that was launched for the treatment of functional dyspepsia in December 2011 in Korea. The heterogeneous symptom pattern and multiple causes of functional dyspepsia have resulted in multiple drug target strategies for its treatment. DA-9701, a compound consisting of a combination of Corydalis Tuber and Pharbitidis Semen, has being developed for treatment of functional dyspepsia. It has multiple mechanisms of action such as fundus relaxation, visceral analgesia, and prokinetic effects. Furthermore, it was found to significantly enhance meal-induced gastric accommodation and increase gastric compliance in dogs. DA-9701 also showed an analgesic effect in rats with colorectal distension induced visceral hypersensitivity and an antinociceptive effect in beagle dogs with gastric distension-induced nociception. The pharmacological effects of DA-9701 also include conventional effects, such as enhanced gastric emptying and gastrointestinal transit. The safety profi le of DA-9701 is also preferable to that of other treatments.

  15. DA-9701: A New Multi-Acting Drug for the Treatment of Functional Dyspepsia

    PubMed Central

    Kwon, Yong Sam; Son, Miwon

    2013-01-01

    Motilitone® (DA-9701) is a new herbal drug that was launched for the treatment of functional dyspepsia in December 2011 in Korea. The heterogeneous symptom pattern and multiple causes of functional dyspepsia have resulted in multiple drug target strategies for its treatment. DA-9701, a compound consisting of a combination of Corydalis Tuber and Pharbitidis Semen, has being developed for treatment of functional dyspepsia. It has multiple mechanisms of action such as fundus relaxation, visceral analgesia, and prokinetic effects. Furthermore, it was found to significantly enhance meal-induced gastric accommodation and increase gastric compliance in dogs. DA-9701 also showed an analgesic effect in rats with colorectal distension induced visceral hypersensitivity and an antinociceptive effect in beagle dogs with gastric distension-induced nociception. The pharmacological effects of DA-9701 also include conventional effects, such as enhanced gastric emptying and gastrointestinal transit. The safety profi le of DA-9701 is also preferable to that of other treatments. PMID:24265862

  16. The First Six Outbursting Cool DA White Dwarf Pulsators

    NASA Astrophysics Data System (ADS)

    Bell, K. J.; Hermes, J. J.; Montgomery, M. H.; Winget, D. E.; Gentile Fusillo, N. P.; Raddi, R.; Gänsicke, B. T.

    2017-03-01

    Extensive observations from the Kepler spacecraft have recently revealed a new outburst phenomenon operating in cool pulsating DA (hydrogen atmosphere) white dwarfs (DAVs). With the introduction of two new outbursting DAVs from K2 Fields 7 (EPIC 229228364) and 8 (EPIC 220453225) in these proceedings, we presently know of six total members of this class of object. We present the observational commonalities of the outbursting DAVs: (1) outbursts that increase the mean stellar flux by up to ≍15%, last many hours, and recur irregularly on timescales of days; (2) effective temperatures that locate them near the cool edge of the DAV instability strip; and (3) rich pulsation spectra with modes that are observed to wander in amplitude/frequency.

  17. A 92-kDa human immunostimulatory protein.

    PubMed Central

    Fontan, E; Briend, E; Saklani-Jusforgues, H; d'Alayer, J; Vandekerckhove, J; Fauve, R M

    1994-01-01

    We purified to apparent homogeneity a human urinary glycoprotein of 92 kDa (HGP.92) that, administered intravenously at 250 micrograms/kg, fully protected mice against a lethal inoculum of Listeria monocytogenes. Since HGP.92 protected scid mice, which lack B and T lymphocytes, this increased resistance to Listeria did not appear to be lymphocyte mediated. Furthermore, inflammatory macrophages incubated with 6 nM HGP.92 inhibited the growth of Lewis carcinoma cells in vitro. These two activities appeared to depend on an oligosaccharide moiety, as they were lost after N-Glycanase treatment of HGP.92. Thus, the biological activity of HGP.92 was in some way related to a glycan moiety. Images PMID:8078887

  18. VLBI Radar of the 2012 DA14 Asteroid

    NASA Astrophysics Data System (ADS)

    Nechaeva, M. B.; Dugin, N. A.; Antipenko, A. A.; Bezrukov, D. A.; Bezrukov, V. V.; Voytyuk, V. V.; Dement'ev, A. F.; Jekabsons, N.; Klapers, M.; Konovalenko, A. A.; Kulishenko, V. F.; Nabatov, A. S.; Nesteruk, V. N.; Putillo, D.; Reznichenko, A. M.; Salerno, E.; Snegirev, S. D.; Tikhomirov, Yu. V.; Khutornoy, R. V.; Skirmante, K.; Shmeld, I.; Chagunin, A. K.

    2015-03-01

    An experiment on VLBI radar of the 2012 DA14 asteroid was carried out on February 15-16, 2011 at the time of its closest approach to the Earth. The research teams of Kharkov (Institute of Radio Astronomy of the National Academy of Sciences of Ukraine), Evpatoria (National Space Facilities Control and Test Center), Nizhny Novgorod (Radiophysical Research Institute), Bologna (Istituto di Radioastronomia (INAF)), and Ventspils (Ventspils International Radioastronomy Center) took part in the experiment. The asteroid was irradiated by the RT-70 planetary radar (Evpatoria) at a frequency of 5 GHz. The reflected signal was received using two 32-m radio telescopes in Medicina (Italy) and Irbene (Latvia) in radiointerferometric mode. The Doppler frequency shifts in bi-static radar mode and interference frequency in VLBI mode were measured. Accuracy of the VLBI radar method for determining the radial and angular velocities of the asteroid were estimated.

  19. Leonardo da Vinci: the search for the soul.

    PubMed

    Del Maestro, R F

    1998-11-01

    The human race has always contemplated the question of the anatomical location of the soul. During the Renaissance the controversy crystallized into those individuals who supported the heart ("cardiocentric soul") and others who supported the brain ("cephalocentric soul") as the abode for this elusive entity. Leonardo da Vinci (1452-1519) joined a long list of other explorers in the "search for the soul." The method he used to resolve this anatomical problem involved the accumulation of information from ancient and contemporary sources, careful notetaking, discussions with acknowledged experts, and his own personal search for the truth. Leonardo used a myriad of innovative methods acquired from his knowledge of painting, sculpture, and architecture to define more clearly the site of the "senso comune"--the soul. In this review the author examines the sources of this ancient question, the knowledge base tapped by Leonardo for his personal search for the soul, and the views of key individuals who followed him.

  20. [Regarding the Manuscript D " Dell' occhio " of Leonardo da Vinci].

    PubMed

    Heitz, Robert F

    2009-01-01

    Leonardo da Vinci's Manuscript D consists of five double pages sheets, which, folded in two, comprise ten folios. This document, in the old Tuscan dialect and mirror writing, reveals the ideas of Leonardo on the anatomy of the eye in relation to the formation of images and visual perception. Leonardo explains in particular the behavior of the rays in the eye in terms of refraction and reflection, and is very mechanistic in his conception of the eye and of the visual process. The most significant innovations found in these folios are the concept of the eye as a camera obscura and the intersection of light rays in the interior of the eye. His texts nevertheless show hesitation, doubts and a troubled confusion, reflecting the ideas and uncertainties of his era. He did not share his results in his lifetime, despite both printing and etching being readily available to him.

  1. Sine ars scientia nihil est: Leonardo da Vinci and beyond.

    PubMed

    Kickhöfel, Eduardo H P

    2009-01-01

    The aim of this article is to reflect on the relationship between art and science so far as it concerns a symposium on neurosciences. We undertake a historical overview of that relationship, paying particular attention to the sui generis case of Leonardo da Vinci, who very often is regarded as the man who worked on art and science with equal ease. We then explain why his idea of merging these two forms of knowledge failed, considering the clear-cut distinction between art and science in his time. With this clarification, we explore the matter today. We look at Raphael's The Transfiguration, in which the representation of the possessed boy is seen by neuroscientists as indicative of an epileptic seizure. We also look at the ideas of neuroscientists Semir Zeki and Vilayanur Ramachandran, who study particular aspects of brain function and suggest a new merging of art and science.

  2. DaVinci-assisted laparoscopic radical prostatectomy: the learning curve

    NASA Astrophysics Data System (ADS)

    Le, Carter Q.; Ho, Khai-Linh V.; Gettman, Matthew T.

    2007-02-01

    Objective: To define the learning curve for daVinci-assisted laparoscopic radical prostatectomy (DLP) at our institution. Methods: The data from 170 patients who underwent DLP between August 2002 and December 2004 by a single surgeon (MTG) were reviewed. Operative time, hemoglobin decrease, conversion to open procedure, positive margin rates, complications, length of stay (LOS), length of catheterization, continence, and erectile function were analyzed. Results: Hemoglobin decrease (p=0.11), positive margin rates (p=0.80), and early urinary continence (p=0.17) did not significantly correlate with surgical experience. A trend towards lower complications (p=0.07) and an earlier return of erectile function (p=0.09) was noted with increased experience with DLP. Operative time, hospital stay, catheterization time, and open conversion showed significant association with patient sequence. Median operative time for the first 60 and the last 110 patients was 323.5 and 239.5 minutes (p=<0.0001), respectively. Median LOS for the aforementioned groups was 53 and 51 hours (p=0.009). Length of catheterization declined significantly between the first 60 and the remaining 110 patients, 14 as compared to 11.5 days (p=<0.0001). Eight open conversions occurred, six were in the first 30 patients (p=0.03). Conclusion: As an indicator of the learning curve, the operative time in our series showed no correlation with sequence after the 60 th patient. Thus, despite the advantages of robotics, the learning curve to efficient performance of daVinciassisted laparoscopic radical prostatectomy is long. Oncological and functional outcomes should not be affected during the learning curve.

  3. Beyond the Classic VTA: Extended Amygdala Projections to DA-Striatal Paths in the Primate.

    PubMed

    Fudge, Julie L; Kelly, Emily A; Pal, Ria; Bedont, Joseph L; Park, Lydia; Ho, Brian

    2017-03-22

    The central extended amygdala (CEA) has been conceptualized as a 'macrosystem' that regulates various stress-induced behaviors. Consistent with this, the CEA highly expresses corticotropin-releasing factor (CRF), an important modulator of stress responses. Stress alters goal-directed responses associated with striatal paths, including maladaptive responses such as drug seeking, social withdrawal, and compulsive behavior. CEA inputs to the midbrain dopamine (DA) system are positioned to influence striatal functions through mesolimbic DA-striatal pathways. However, the structure of this amygdala-CEA-DA neuron path to the striatum has been poorly characterized in primates. In primates, we combined neuronal tracer injections into various arms of the circuit through specific DA subpopulations to assess: (1) whether the circuit connecting amygdala, CEA, and DA cells follows CEA intrinsic organization, or a more direct topography involving bed nucleus vs central nucleus divisions; (2) CRF content of the CEA-DA path; and (3) striatal subregions specifically involved in CEA-DA-striatal loops. We found that the amygdala-CEA-DA path follows macrostructural subdivisions, with the majority of input/outputs converging in the medial central nucleus, the sublenticular extended amygdala, and the posterior lateral bed nucleus of the stria terminalis. The proportion of CRF+ outputs is >50%, and mainly targets the A10 parabrachial pigmented nucleus (PBP) and A8 (retrorubal field, RRF) neuronal subpopulations, with additional inputs to the dorsal A9 neurons. CRF-enriched CEA-DA projections are positioned to influence outputs to the 'limbic-associative' striatum, which is distinct from striatal regions targeted by DA cells lacking CEA input. We conclude that the concept of the CEA is supported on connectional grounds, and that CEA termination over the PBP and RRF neuronal populations can influence striatal circuits involved in associative learning.Neuropsychopharmacology advance online

  4. Pharmacological action of DA-9701 on the motility of feline stomach circular smooth muscle.

    PubMed

    Nguyen, Thanh Thao; Song, Hyun Ju; Ko, Sung Kwon; Sohn, Uy Dong

    2015-03-01

    DA-9701, a new prokinetic agent for the treatment of functional dyspepsia, is formulated with Pharbitis semen and Corydalis tuber. This study wasconducted to determine the pharmacological action of DA-9701 and to identify the receptors involved in DA-9701 -induced contractile responsesin the feline gastric corporal, fundic and antral circular smooth muscle. Concentration-response curve to DA-9701 was established. The tissue trips were exposed to methylsergide, ketanserin, ondansetron, GR 113808, atropine and dopamine before administration of DA-9701. The contractile force was determined before and after administration of drugs by a polygraph.DA-9701 enhanced the spontaneous contractile amplitude of antrum, corpus and fundus. However, it did not change the spontaneous contractile frequency of antrum and corpus, but concentration-dependently reduced that of fundus. In the fundus, DA-9701 -induced tonic contractions were inhibited by dopamine, methylsergide, ketanserine, ondansetron or GR 113808 respectively, but not by atropine, indicating that the contractile responses are mediated by multiple receptors: 5-HT2, 5-HT3, 5-HT4, and dopamine receptors. In the corpus, DA-9701-induced contractions were blocked by atropine, dopamine or GR 113808, but not by methysergide, ketanserin or ondansetron, indicating that they are involved in receptors on both, smooth muscles and neurons: 5-HT4 and dopamine receptors. However, contractile responses to DA-9701 are mainly mediated by dopamine receptors in the antrum. These results suggest that DA-9701 has important roles in gastric accommodation by enhancing tonic activity of fundus, and in gastric emptying and gastrointestinal transit by phasic contractions of corpus and antrum mediated by multiple receptors.

  5. Reduced striatal dopamine DA D2 receptor function in dominant-negative GSK-3 transgenic mice.

    PubMed

    Gomez-Sintes, Raquel; Bortolozzi, Analia; Artigas, Francesc; Lucas, José J

    2014-09-01

    Glycogen synthase kinase-3 (GSK-3) is a serine/threonine kinase with constitutive activity involved in cellular architecture, gene expression, cell proliferation, fate decision and apoptosis, among others. GSK-3 expression is particularly high in brain where it may be involved in neurological and psychiatric disorders such as Alzheimer׳s disease, bipolar disorder and major depression. A link with schizophrenia is suggested by the antipsychotic drug-induced GSK-3 regulation and by the involvement of the Akt/GSK-3 pathway in dopaminergic neurotransmission. Taking advantage of the previous development of dominant negative GSK-3 transgenic mice (Tg) showing a selective reduction of GSK-3 activity in forebrain neurons but not in dopaminergic neurons, we explored the relationship between GSK-3 and dopaminergic neurotransmission in vivo. In microdialysis experiments, local quinpirole (DA D2-R agonist) in dorsal striatum reduced dopamine (DA) release significantly less in Tg mice than in wild-type (WT) mice. However, local SKF-81297 (selective DA D1-R agonist) in dorsal striatum reduced DA release equally in both control and Tg mice indicating a comparable function of DA D1-R in the direct striato-nigral pathway. Likewise, systemic quinpirole administration - acting preferentially on presynaptic DA D2- autoreceptors to modulate DA release-reduced striatal DA release similarly in both control and Tg mice. Quinpirole reduced locomotor activity and induced c-fos expression in globus pallidus (both striatal DA D2-R-mediated effects) significantly more in WT than in Tg mice. Taking together, the present results show that dominant negative GSK-3 transgenic mice show reduced DA D2-R-mediated function in striatum and further support a link between dopaminergic neurotransmission and GSK-3 activity.

  6. Therapeutic effect of DA-9601 on chronic reflux gastritis induced by sodium taurocholate in rats

    PubMed Central

    Oh, Tae Young; Shin, Chang Yell; Sohn, Yong Sung; Kim, Dong Hwan; Ahn, Byoung Ok; Lee, Eun Bang; Park, Cho Hyun

    2005-01-01

    AIM: To investigate the therapeutic effects of DA-9601 on sodium taurocholate (TCA)-induced chronic reflux gastritis in SD rats. METHODS: In this study, we have investigated the therapeutic effects of DA-9601 on chronic erosive and atrophic gastritis induced by 6 mo of TCA administration (5 mmol/L in drinking water) in SD rats. RESULTS: Four weeks of DA-9601 administration (0.065%, 0.216% in rat chow), following the withdrawal of TCA treatment, resulted in a significant decrease in total length of erosions in rats in a dose-dependent manner. Furthermore, the indicators of atrophic gastritis, such as reduced mucosal thickness and reduction in the number of parietal cells, were improved by the administration of DA-9601 in a dose-related manner. DA-9601 also attenuated inflammatory cell infiltration and the proliferation of collagenous fiber in the gastric mucosa. The improvement in the reduction of the gastric mucus was observed in the rats receiving a high dose of DA-9601 (0.216%). The therapeutic effect of DA-9601 on experimental chronic erosive gastritis was superior to that of rebamipide (1.08% in rat chow). Biochemical analyses showed increased mucosal prostaglandin E2 and reduced glutathione levels by DA-9601 treatment. CONCLUSION: We suggest that DA-9601 is a promising agent for the treatment of chronic erosive and atrophic gastritis with an etiological factor of bile reflux. Increased mucosal prostaglandin E2 and reduced glutathione by DA-9601 treatment may be therapeutic mechanisms for chronic erosive and atrophic gastritis. PMID:16437712

  7. The Effect of DA-9701 in Opioid-induced Bowel Dysfunction of Guinea Pig

    PubMed Central

    Hussain, Zahid; Rhee, Kwang Won; Lee, Young Ju; Park, Hyojin

    2016-01-01

    Background/Aims Opioid induced bowel dysfunction (OIBD) is associated with decreased gastrointestinal (GI) propulsive activity due to intake of opioid analgesics. DA-9701, a novel prokinetic agent formulated with Pharbitis Semen and Corydalis Tuber has promising effects on GI motor function. Therefore, we aim to evaluate the prokinetic effects of DA-9701 in an OIBD model of guinea pig. Methods The ileal and distal colon muscle contraction in presence of different doses of DA-9701, morphine, and combination (morphine + DA-9701) was measured by tissue bath study. The prokinetic effect of DA-9701 was assessed by charcoal transit and fecal pellet output assay in an OIBD model of guinea pig. Results DA-9701 significantly increased the amplitude and area under the curve of ileal muscle contraction, while there was insignificant effect on the distal colon compared to the control. The maximal amplitude of ileal muscle contraction was acquired at a concentration of 10 μg/mL of DA-9701. In contrast, morphine significantly decreased the amplitude of ileal and distal colon muscle contraction compared to the control. Morphine delayed both upper (P < 0.01) and lower (P < 0.05) GI transit, and delayed GI transit was restored by the administration of DA-9701. Morphine induced reduction of contractility was significantly ameliorated by addition of DA-9701 in both ileal and distal colon muscles. Conclusions DA-9701 significantly increased the amplitude of contraction of the ileal muscle, however the distal colon muscle contraction was insignificant. Additionally, it restored delayed upper and lower GI transit in an OIBD model of guinea pig, and it might prove to be a useful candidate drug in a clinical trial for OIBD. PMID:26932898

  8. Beyond Donor-Acceptor (D-A) Approach: Structure-Optoelectronic Properties-Organic Photovoltaic Performance Correlation in New D-A1 -D-A2 Low-Bandgap Conjugated Polymers.

    PubMed

    Chochos, Christos L; Drakopoulou, Sofia; Katsouras, Athanasios; Squeo, Benedetta M; Sprau, Christian; Colsmann, Alexander; Gregoriou, Vasilis G; Cando, Alex-Palma; Allard, Sybille; Scherf, Ullrich; Gasparini, Nicola; Kazerouni, Negar; Ameri, Tayebeh; Brabec, Christoph J; Avgeropoulos, Apostolos

    2017-04-01

    Low-bandgap near-infrared polymers are usually synthesized using the common donor-acceptor (D-A) approach. However, recently polymer chemists are introducing more complex chemical concepts for better fine tuning of their optoelectronic properties. Usually these studies are limited to one or two polymer examples in each case study so far, though. In this study, the dependence of optoelectronic and macroscopic (device performance) properties in a series of six new D-A1 -D-A2 low bandgap semiconducting polymers is reported for the first time. Correlation between the chemical structure of single-component polymer films and their optoelectronic properties has been achieved in terms of absorption maxima, optical bandgap, ionization potential, and electron affinity. Preliminary organic photovoltaic results based on blends of the D-A1 -D-A2 polymers as the electron donor mixed with the fullerene derivative [6,6]-phenyl-C71 -butyric acid methyl ester demonstrate power conversion efficiencies close to 4% with short-circuit current densities (J sc ) of around 11 mA cm(-2) , high fill factors up to 0.70, and high open-circuit voltages (V oc s) of 0.70 V. All the devices are fabricated in an inverted architecture with the photoactive layer processed in air with doctor blade technique, showing the compatibility with roll-to-roll large-scale manufacturing processes.

  9. 43 kDa and 66 kDa, two blood stage antigens induce immune response in Plasmodium berghei malaria.

    PubMed

    Pirta, Chhaya; Banyal, H S

    2014-08-01

    The hunt for an effective vaccine against malaria still continues. Several new target antigens as candidates for vaccine design are being explored and tested for their efficacy. In the present study the sera from mice immunized with 24,000 x g fraction of Plasmodium berghei has been used to identify highly immunogenic blood stage antigens. The protective antibodies present in immune sera were covalently immobilized on CNBr activated sepharose 4B and used for affinity chromatography purification of antigens present in blood stages of P. berghei. Two polypeptides of 66 and 43 kDa molecular weights proved to be highly immunogenic. They exhibited a strong humoral immune response in mice as evident by high titres in ELISA and IFA. Protective immunity by these two antigens was apparent by in vivo and in vitro studies. These two proteins could further be analysed and used as antigens in malaria vaccine design.

  10. Vectra DA for the objective measurement of disease activity in patients with rheumatoid arthritis.

    PubMed

    Segurado, O G; Sasso, E H

    2014-01-01

    Quantitative and regular assessment of disease activity in rheumatoid arthritis (RA) is required to achieve treatment targets such as remission and to optimize clinical outcomes. To assess inflammation accurately, predict joint damage and monitor treatment response, a measure of disease activity in RA should reflect the pathological processes resulting in irreversible joint damage and functional disability. The Vectra DA blood test is an objective measure of disease activity for patients with RA. Vectra DA provides an accurate, reproducible score on a scale of 1 to 100 based on the concentrations of 12 biomarkers that reflect the pathophysiologic diversity of RA. The analytical validity, clinical validity, and clinical utility of Vectra DA have been evaluated for patients with RA in registries and prospective and retrospective clinical studies. As a biomarker-based instrument for assessing disease activity in RA, the Vectra DA test can help monitor therapeutic response to methotrexate and biologic agents and assess clinically challenging situations, such as when clinical measures are confounded by non-inflammatory pain from fibromyalgia. Vectra DA scores correlate with imaging of joint inflammation and are predictive for radiographic progression, with high Vectra DA scores being associated with more frequent and severe progression and low scores being predictive for non-progression. In summary, the Vectra DA score is an objective measure of RA disease activity that quantifies inflammatory status. By predicting risk for joint damage more effectively than conventional clinical and laboratory measures, it has the potential to complement these measures and optimise clinical decision making.

  11. Biofortification of soybean meal: immunological properties of the 27 kDa γ-zein.

    PubMed

    Krishnan, Hari B; Jang, Sungchan; Kim, Won-Seok; Kerley, Monty S; Oliver, Melvin J; Trick, Harold N

    2011-02-23

    Legumes, including soybeans ( Glycine max ), are deficient in sulfur-containing amino acids, which are required for the optimal growth of monogastric animals. This deficiency can be overcome by expressing heterologous proteins rich in sulfur-containing amino acids in soybean seeds. A maize 27 kDa γ-zein, a cysteine-rich protein, has been successfully expressed in several crops including soybean, barley, and alfalfa with the intent to biofortify these crops for animal feed. Previous work has shown that the maize 27 kDa zein can withstand digestion by pepsin and elicit an immunogenic response in young pigs. By use of sera from patients who tested positive by ImmunoCAP assay for elevated IgE to maize proteins, specific IgE binding to the 27 kDa γ-zein is demonstrated. Bioinformatic analysis using the full-length and 80 amino acid sliding window FASTA searches identified significant sequence homology of the 27 kDa γ-zein with several known allergens. Immunoblot analysis using human serum that cross-reacts with maize seed proteins also revealed specific IgE-binding to the 27 kDa γ-zein in soybean seed protein extracts containing the 27 kDa zein. This study demonstrates for the first time the allergenicity potential of the 27 kDa γ-zein and the potential that this protein has to limit livestock performance when used in soybeans that serve as a biofortified feed supplement.

  12. Essential roles of Da transactivation domains in neurogenesis and in E(spl)-mediated repression.

    PubMed

    Zarifi, Ioanna; Kiparaki, Marianthi; Koumbanakis, Konstantinos A; Giagtzoglou, Nikolaos; Zacharioudaki, Evanthia; Alexiadis, Anastasios; Livadaras, Ioannis; Delidakis, Christos

    2012-11-01

    E proteins are a special class of basic helix-loop-helix (bHLH) proteins that heterodimerize with many bHLH activators to regulate developmental decisions, such as myogenesis and neurogenesis. Daughterless (Da) is the sole E protein in Drosophila and is ubiquitously expressed. We have characterized two transcription activation domains (TADs) in Da, called activation domain 1 (AD1) and loop-helix (LH), and have evaluated their roles in promoting peripheral neurogenesis. In this context, Da heterodimerizes with proneural proteins, such as Scute (Sc), which is dynamically expressed and also contributes a TAD. We found that either one of the Da TADs in the Da/Sc complex is sufficient to promote neurogenesis, whereas the Sc TAD is incapable of doing so. Besides its transcriptional activation role, the Da AD1 domain serves as an interaction platform for E(spl) proteins, bHLH-Orange family repressors which antagonize Da/Sc function. We show that the E(spl) Orange domain is needed for this interaction and strongly contributes to the antiproneural activity of E(spl) proteins. We present a mechanistic model on the interplay of these bHLH factors in the context of neural fate assignment.

  13. Antimicrobial Properties of an Immunomodulator - 15 kDa Human Granulysin

    PubMed Central

    Wei, Hung-Mu; Lin, Li-Chih; Wang, Chiu-Feng; Lee, Yi-Jang; Chen, Yuan-Tsong; Liao, You-Di

    2016-01-01

    Granulysin, a cationic protein expressed by human natural killer cells and cytotoxic T lymphocytes, is a mediator for drug-induced Stevens-Johnson syndrome and graft-versus-host disease. Some 15 kDa granulysin are processed into 9 kDa forms and sequestered in cytolytic granules, while others are constitutively secreted into body fluids. Both 9 and 15 kDa granulysin have been shown to be a serum marker for cell-mediated immunity. Furthermore, 15 kDa is able to activate monocyte differentiation. However, its antimicrobial properties have not been clearly addressed. Here, we report a novel method to prepare both the soluble 9 and 15 kDa granulysin and show that the 15 kDa form is more effective than the 9 kDa form in exerting specific antimicrobial activity against Pseudomonas aeruginosa within a range of few micromolars. We also show that the 15 kDa granulysin is able to hyperpolarize the membrane potential and increase membrane permeability of treated bacteria. Interestingly, the bactericidal activity and membrane permeability of the granulysins were markedly reduced at lower pH (pH 5.4) as a result of probable increase in hydrophobicity of the granulysins. Additionally, we’ve also shown the granulysin to inhibit biofilm formation by P. aeruginosa. These results suggest that the 15 kDa granulysin exhibits a novel mechanism in bacteria killing in a way that’s different from most antimicrobial peptides. Our novel granulysin preparation methodology will be useful for further study of action mechanisms of other antimicrobial, cytotoxic and immunomodulating properties in granulysin-mediated diseases. PMID:27276051

  14. Therapeutic effect of infused Fluosol-DA/carbogen with ephedrine, flunarizine, or nitroprusside

    SciTech Connect

    Teicher, B.A.; Holden, S.A.; Northey, D.; Dewhirst, M.W.; Herman, T.S.

    1993-04-30

    The perfluorochemical emulsion Fluosol-DA plus carbogen breathing has been shown to increase the effectiveness of radiation therapy in preclinical solid tumors when the emulsion was administered by i.v. bolus injection. Much of the enhancement in tumor radiation response was lost when the emulsion was administered slowly. The authors hypothesized that an increase in tumor perfusion resulted when Fluosol-DA was administered rapidly. In the present study, the [alpha]/[beta] agonist ephedrine, the Ca[sup 2+] channel blocker flunarizine and the nitric oxide producing vasodilating drug nitroprusside have been tested. Ephedrine administration resulted in a decrease in the radiation plus Fluosol-DA [+-] carbogen antitumor effects in both the Lewis lung carcinoma and FSaIIC tumor systems. In contrast, flunarizine administration resulted in an increase in the efficacy of the radiation plus carbogen and the radiation plus Fluosol-DA/carbogen in both emulsion was given rapidly. Even with flunarizine administration Fluosol-DA delivered slowly was less effective than when the emulsion was given rapidly. Flunarizine with Fluosol-DA infused i.v. over 30 min followed by carbogen breathing prior to and during radiation therapy resulted in a 1.7-1.6-fold increase in response compared with 2.4-2.2-fold with Fluosol-DA administered by injection i.v. and carbogen breathing prior to and during radiation therapy using growth delay of the Lewis lung carcinoma. The effects of nitroprusside were complex. This drug had considerably more effect at 10 Gy than at higher radiation doses. These studies suggest that Fluosol-DA given by i.v. injection may increase tumor perfusion and that a drug like flunarizine may be beneficial if the Fluosol-DA is administered slowly followed by carbogen breathing and radiation therapy. 45 refs., 4 figs.

  15. Pharmacokinetics of intravenous and oral DA-8159, a new erectogenic, in rats with protein-calorie malnutrition.

    PubMed

    Shim, Hyun J; Kim, Yu C; Lee, Joo H; Ahn, Byung O; Kwon, Jong W; Kim, Won B; Lee, Inchul; Lee, Myung G

    2004-12-01

    Influence of dietary protein deficiency on the pharmacokinetics of DA-8159 and one of its metabolites, DA-8164, was investigated after intravenous and oral administration of DA-8159 at a dose of 30 mg kg(-1) to male Sprague-Dawley rats allowed free access to a 23% (control) or 5% (protein-calorie malnutrition, PCM) casein diet for 4 weeks. The total area under the plasma concentration-time curve from time zero to time infinity (AUC) values of DA-8164 were significantly smaller after both intravenous (87.0 vs 162 microg min mL(-1)) and oral (144 vs 319 microg min mL(-1)) administration of DA-8159 to PCM rats. This could be due to the decrease in CYP3A1/2 (50-60%) in the rats because DA-8164 was mainly formed via CYP3A1/2 in rats. This could be supported by significantly slower in-vitro CL(int) (2.04+/-0.646 vs 3.15+/-0.693 microL min(-1) (mg protein)(-1)) for the formation of DA-8164 in hepatic microsomal fraction of PCM rats. After intravenous administration of DA-8159, the AUC values of DA-8159 were not significantly different between the two groups of rats although the AUC of DA-8164 was significantly smaller in PCM rats, and this may be due to the minor metabolic pathway of DA-8164 in rats. However, after oral administration of DA-8159, the AUC of DA-8159 was significantly greater in PCM rats (194 vs 122 microg min mL(-1)). This was not due to enhanced absorption of DA-8159 from the gastrointestinal tract in the rats but may be due to a decreased intestinal first-pass effect of DA-8159 in the rats.

  16. Respostas religiosas à aids no Brasil: impressões de pesquisa acerca da Pastoral de DST/Aids da Igreja Católica1

    PubMed Central

    Seffner, Fernando; Silva, Cristiane Gonçalves Meireles da; Maksud, Ívia; Garcia, Jonathan; Rios, Luís Felipe; Natividade, Marcelo; Borges, Priscila Rodrigues; Parker, Richard; Terto, Veriano

    2009-01-01

    O texto encontra-se estruturado em quatro partes. Na primeira delas, apresentamos um conjunto de considerações e informações acerca da situação da aids no Brasil, das relações entre religião, sexualidade, aids e estado laico, bem como uma descrição mais clara do Projeto Respostas Religiosas ao HIV/Aids no Brasil, do qual este texto apresenta algumas impressões de pesquisa preliminares. A seguir, dedicamos um item a apresentação da Pastoral de DST/Aids, sua história, estrutura e objetivos. No item seguinte problematizamos diversas questões em particular no âmbito das relações Estado e Igreja, relações entre agentes de pastoral e hierarquia da Igreja, e questões ligadas mais diretamente à sexualidade e aids, todas referenciadas ao trabalho da Pastoral de DST/Aids. Ao final, apresentamos a bibliografia e fontes consultadas. PMID:20442806

  17. MALDI-TOF High Mass Calibration up to 200 kDa Using Human Recombinant 16 kDa Protein Histidine Phosphatase Aggregates

    PubMed Central

    Ludwig, Katrin; Habbach, Schähdi; Krieglstein, Josef; Klumpp, Susanne; König, Simone

    2011-01-01

    Background Protein histidine phosphatase (PHP) is an enzyme which removes phosphate groups from histidine residues. It was described for ver