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Sample records for 8-mop mas uva

  1. Cytochrome P450 CYP1B1 Interacts with 8-Methoxypsoralen (8-MOP) and Influences Psoralen-Ultraviolet A (PUVA) Sensitivity

    PubMed Central

    Deeni, Yusuf Y.; Ibbotson, Sally H.; Woods, Julie A.; Wolf, C. Roland; Smith, Gillian

    2013-01-01

    Background There are unpredictable inter-individual differences in sensitivity to psoralen-UVA (PUVA) photochemotherapy, used to treat skin diseases including psoriasis. Psoralens are metabolised by cytochrome P450 enzymes (P450), and we hypothesised that variability in cutaneous P450 expression may influence PUVA sensitivity. We previously showed that P450 CYP1B1 was abundantly expressed in human skin and regulated by PUVA, and described marked inter-individual differences in cutaneous CYP1B1 expression. Objectives We investigated whether CYP1B1 made a significant contribution to 8-methoxypsoralen (8-MOP) metabolism, and whether individuality in CYP1B1 activity influenced PUVA sensitivity. Methods We used E. coli membranes co-expressing various P450s and cytochrome P450 reductase (CPR) to study 8-MOP metabolism and cytotoxicity assays in CYP1B1-expressing mammalian cells to assess PUVA sensitivity. Results We showed that P450s CYP1A1, CYP1A2, CYP1B1, CYP2A6 and CYP2E1 influence 8-MOP metabolism. As CYP1B1 is the most abundant P450 in human skin, we further demonstrated that: (i) CYP1B1 interacts with 8-MOP (ii) metabolism of the CYP1B1 substrates 7-ethoxyresorufin and 17-β-estradiol showed concentration-dependent inhibition by 8-MOP and (iii) inhibition of 7-ethoxyresorufin metabolism by 8-MOP was influenced by CYP1B1 genotype. The influence of CYP1B1 on PUVA cytotoxicity was further investigated in a Chinese hamster ovary cell line, stably expressing CYP1B1 and CPR, which was more sensitive to PUVA than control cells, suggesting that CYP1B1 metabolises 8-MOP to a more phototoxic metabolite(s). Conclusion Our data therefore suggest that CYP1B1 significantly contributes to cutaneous 8-MOP metabolism, and that individuality in CYP1B1 expression may influence PUVA sensitivity. PMID:24086543

  2. Dynamics of in-vitro fluorescence of human epidermis with applied 8-MOP

    NASA Astrophysics Data System (ADS)

    Chernova, Svetlana P.; Pravdin, Alexander B.; Bukatova, E. V.; Kochubey, Vyacheslav I.

    1997-02-01

    Experiments on studying of the dynamics of luminescence intensity under continuous 360 plus or minus 20 nm irradiation were conducted on normal human epidermis sampled using surface epidermal stripping technique and treated with 8-MOP in vitro. Alterations in luminescence spectra after one hour continuous UV irradiation differ in pure and psoralen treated epidermis. Kinetic curves (luminescence intensity at different wavelengths versus time of irradiation) for 8-MOP treated epidermis have the period of luminescence 'glowing up' which covers first 300 - 400 sec of irradiation time then much more gently stopping bleaching region which goes in intensity lower than initial (before irradiation) level. In the frame of the kinetic scheme for luminescent photoproduct, comprising two consecutive first order reactions, values of rate constants of luminescence 'growing up' and diminution were calculated.

  3. UVA radiation augments cytotoxic activity of psoralens in melanoma cells.

    PubMed

    Wrześniok, Dorota; Beberok, Artur; Rok, Jakub; Delijewski, Marcin; Hechmann, Anna; Oprzondek, Martyna; Rzepka, Zuzanna; Bacler-Żbikowska, Barbara; Buszman, Ewa

    2017-07-01

    Melanoma is an aggressive form of skin cancer. The aim of the study was to evaluate the influence of UVA radiation and psoralens: 5-methoxypsoralen (5-MOP) or 8-methoxypsoralen (8-MOP) on melanoma cells viability. The amelanotic C32 and melanotic COLO829 human melanoma cell lines were exposed to increasing concentrations of psoralens (0.1-100 μM) in the presence or absence of UVA radiation. Cell viability was evaluated by the WST-1 assay. We demonstrated that 8-MOP, in contrast to 5-MOP, has no cytotoxic effect on both melanoma cell lines. Simultaneous exposure of cells to 8-MOP and UVA radiation caused significant cytotoxic response in C32 cells where the EC50 value was estimated to be 131.0 μM (UVA dose: 1.3 J/cm(2)) and 105.3 μM (UVA dose: 2.6 J/cm(2)). The cytotoxicity of 5-MOP on both C32 and COLO829 cells was significantly augmented by UVA radiation - the EC50 was estimated to be 22.7 or 7.9 μM (UVA dose: 1.3 J/cm(2)) and 24.2 or 7.0 μM (UVA dose: 2.6 J/cm(2)), respectively. The demonstrated high cytotoxic response after simultaneous exposure of melanoma cells to psoralens and UVA radiation in vitro suggests the usefulness of PUVA therapy to treat melanoma in vivo.

  4. Distribution of 3H-8-MOP and its metabolites in rat organs after a single oral administration

    SciTech Connect

    Wulf, H.C.; Andreasen, M.P.

    1981-04-01

    Concentrations of 3H-8-methoxypsoralen (MOP), its lipid- and water soluble metabolites and tritiated water have been measured in rat serum, liver, kidney, and skin, using liquid scintillation, thin-layer chromatography and other techniques. Radioactivity in whole blood, plasma, ovary, adrenals, and pancreas has also been measured. The radioactivty has been measured up to 1 week after medication, while 3H-8-MOP and metabolite concentrations have been measured from 10 min to 24 h after medication with a single dose of 1 mg 3H-8-MOP in solution/kg bodyweight. Maximum 8-MOP concentrations were seen from 10 to 30 min after dosing. The concentrations in microgram/kg 10 min, 2 h, and 24 h after medication were as follows: serum--686, 57, 2.1; liver--489, 45, 3.3; kidney--1708, 139, 4.3; and skin--55, 16, 3.8. The concentrations of water soluble metabolites were very high in the liver and only slightly lower in the kidney. The concentrations of these metabolites might accumulate after doses repeated 4 times a week. 3H-8-MOP and its metabolites would not show similar accumulation. Most of the radioactivity present after 1 week is due to trititated water.

  5. 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.

  6. 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.

  7. Induction of keratinocyte apoptosis by photosensitizing chemicals plus UVA.

    PubMed

    Kurita, Masako; Shimauchi, Takatoshi; Kobayashi, Miwa; Atarashi, Kenji; Mori, Koji; Tokura, Yoshiki

    2007-02-01

    The capacity of photosensitizing chemicals with ultraviolet A light (UVA) to induce apoptosis is one of the methods to assess their phototoxic and potentially photoallergic properties, since apoptotic cells may be easily presented by antigen-presenting cells. We examined the photoaggravated ability to induce keratinocyte apoptosis of various chemicals that are known as causative agents of photocontact dermatitis and drug photosensitivity involving photoallergic and/or phototoxic mechanisms. HaCaT keratinocytes were incubated with 3,3',4',5-tetrachlorosalicylanilide (TCSA), bithionol, diphenylhydramine, chlorpromazine, 6-methylcoumarin, sparfloxacin, and enoxacin at 10(-7) to 10(-4)M and irradiated with UVA at 4J/cm(2). As positive control, 8-methoxypsoralen (8-MOP) was also tested. Apoptosis and necrosis were evaluated by flow cytometric enumeration of annexin V(+) 7-AAD(-) and annexin V(+) 7-AAD(+) cells, respectively. The expression of apoptosis-related molecules, caspase-3 and poly (ADP-ribose) polymerase (PARP), was tested by flow cytometric and Western blotting analyses. In a comparison with non-irradiated cells, significant apoptosis was found in TCSA, bithionol, chlorpromazine, sparfloxacin and enoxacin at 10(-4) or 10(-5)M as well as 8-MOP as assessed by both annexin V and active caspase-3 stainings, while necrosis occurred in most of these chemicals at 10(-4)M. Neither apoptosis nor necrosis was seen in diphenylhydramine or 6-methylcoumarin. PARP were activated in HaCaT cells phototreated with TCSA, bithionol and chlorpromazine. We suggest that our method is useful for in vitro assessment of phototoxicity and potential photoallergenicity of chemicals.

  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. 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.

  10. 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.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. 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.

  18. UVA1 a promising approach for scleroderma

    PubMed Central

    Keyal, Uma; Bhatta, Anil Kumar; Wang, Xiu Li

    2017-01-01

    Scleroderma is a complex connective tissue disease characterized by fibrosis, vasculopathy, and immune system dysfunction. The heterogeneity of disease presentation and poorly understood etiology has made the management of scleroderma difficult. The available treatment options like immunosuppressive agents are associated with potentially hazardous side effects and physiotherapy, which to a certain degree helps to minimize the loss of function in digits and limbs, has only limited success. Also, studies investigating antifibrotic therapies have failed to report any significant improvement. Hence, there is currently no effective therapy for scleroderma. Recently, phototherapy has been extensively studied and found to be effective in treating scleroderma. Initially psoralen + ultraviolet A (PUVA) significantly enriched the therapeutic panel, but more recently ultraviolet A1 (UVA1) is seen to replace PUVA therapy. This might be because of UVA1 therapy being free of side effects seen with psoralens such as nausea, vomiting or photokeratitis. In addition, UVA1 is seen to lower risk of phototoxic reactions with deeper penetration of radiation. The present review will put some light on the use of UVA1 for treating cutaneous lesion in scleroderma and we aim to find the most benefitted group of patients and most effective dose of UVA1 for different types of scleroderma. PMID:28979701

  19. UVA1 a promising approach for scleroderma.

    PubMed

    Keyal, Uma; Bhatta, Anil Kumar; Wang, Xiu Li

    2017-01-01

    Scleroderma is a complex connective tissue disease characterized by fibrosis, vasculopathy, and immune system dysfunction. The heterogeneity of disease presentation and poorly understood etiology has made the management of scleroderma difficult. The available treatment options like immunosuppressive agents are associated with potentially hazardous side effects and physiotherapy, which to a certain degree helps to minimize the loss of function in digits and limbs, has only limited success. Also, studies investigating antifibrotic therapies have failed to report any significant improvement. Hence, there is currently no effective therapy for scleroderma. Recently, phototherapy has been extensively studied and found to be effective in treating scleroderma. Initially psoralen + ultraviolet A (PUVA) significantly enriched the therapeutic panel, but more recently ultraviolet A1 (UVA1) is seen to replace PUVA therapy. This might be because of UVA1 therapy being free of side effects seen with psoralens such as nausea, vomiting or photokeratitis. In addition, UVA1 is seen to lower risk of phototoxic reactions with deeper penetration of radiation. The present review will put some light on the use of UVA1 for treating cutaneous lesion in scleroderma and we aim to find the most benefitted group of patients and most effective dose of UVA1 for different types of scleroderma.

  20. 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.

  1. Pyrimidine dimer formation by UVA radiation: Implications for photoreactivation

    SciTech Connect

    Sutherland, B.M.; Hacham, H.; Sutherland, J.C. ); Gange, R.W. . Dept. of Dermatology)

    1991-01-01

    The duality of biological and biochemical effects mediated by UVA radiation complicates evaluation of its biological role. On the one hand, UVA can drive photoreactivation and prevent inactivation of a UV-irradiated organism; on the other hand, UVA clearly kills cells. We have investigated the ability of UVA to induce pyrimidine dimers in human skin in situ. Results of these studies indicate that UVA induces easily quantifiable levels of pyrimidine dimers in the DNA of human skin exposed in situ; and significant levels of dimers are induced in skin exposed to biologically relevant UVA doses (0--1 minimal erythemal dose (MED)). Also, UVA doses appropriate for photorepair may induce sufficient dimer frequencies to mask photoreactivation in biological systems, including human skin. Therefore, careful design of photoreactivation experiments is essential. The UV lamp used must not reverse or convert photodamage, nor induce additional lesions in the DNA. 29 refs., 4 figs., 2 tabs.

  2. Diversity of Biological Effects Induced by Longwave UVA Rays (UVA1) in Reconstructed Skin

    PubMed Central

    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

  3. 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.

  4. Porphyra-334, a potential natural source for UVA protective sunscreens.

    PubMed

    Torres, Avital; Enk, Claes D; Hochberg, Malka; Srebnik, Morris

    2006-04-01

    The mycosporine-like amino acid (MAA), porphyra-334 (lambda(max) = 334 nm; epsilon = 42,300 M(-1) cm(-1)), was isolated from the aquatic cyanobacterium Aphanizomenon flos-aquae (AFA) and its structure was verified by spectroscopic methods. The UVA absorption properties of the crude methanolic extract were determined against two commercial sun care products in terms of mean critical wavelength, mean UVA/UVB ratios and UVA protection category (Boots the Chemists, Ltd.). The crude methanolic extract from AFA exhibited maximum UVA protection comparable to that determined for Boots SPF 4.

  5. 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.

  6. Phyllosphere Methylobacterium bacteria contain UVA-absorbing compounds.

    PubMed

    Yoshida, Shigenobu; Hiradate, Syuntaro; Koitabashi, Motoo; Kamo, Tsunashi; Tsushima, Seiya

    2017-02-01

    Microbes inhabiting the phyllosphere encounter harmful ultraviolet rays, and must develop adaptive strategies against this irradiation. In this study, we screened bacterial isolates originating from the phyllosphere of various plants which harbored absorbers of ultraviolet A (UVA), a wavelength range which is recognized as harmful to human skin. Of the 200 phyllosphere bacterial isolates we screened, methanol extracts from bacterial cells of seventeen isolates absorbed wavelengths in the range of 315-400nm. All of the UVA-absorbing strains belonged to Methylobacterium species based on 16S ribosomal RNA gene sequences, suggesting that cells of this bacterial genus contain specific UVA-absorbing compounds. When cells of a representative Methylobacterium strain were extracted using various solvents, UVA absorption was observed in the extracts obtained using several aqueous solvents, indicating that the UVA-absorbing compounds were highly polar. A compound was purified using solid columns and HPLC separation, and comparative analysis revealed that the absorption strength and spectrum of the compound were similar to those of the known UVA filter, avobenzone. The compound was also verified to be stable under UVA exposure for at least 480min. Based on these results, the UVA-absorbing compound harbored by Methylobacterium has potential to be used as a novel sunscreen ingredient. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Evaluation of the cloudy sky solar UVA radiation exposures.

    PubMed

    Parisi, A V; Downs, N; Turner, J

    2014-09-05

    The influence of cloud on the solar UVA (320-400 nm) exposures over five minute periods on a horizontal plane has been investigated. The first approach used cloud modification factors that were evaluated using the influence of clouds on the global solar exposures (310-2800 nm) and a model developed to apply these to the clear sky UVA exposures to allow calculation of the five minute UVA exposures for any cloud conditions. The second approach established a relationship between the UVA and the global solar exposures. The models were developed using the first six months of data in 2012 for SZA less than or equal to 70° and were applied and evaluated for the exposures in the second half of 2012. This comparison of the modelled exposures for all cloud conditions to the measured data provided an R(2) of 0.8 for the cloud modification model, compared to an R(2) of 0.7 for the UVA/global model. The cloud modification model provided 73% of the five minute exposures within 20% of the measured UVA exposures. This was improved to 89% of the exposures within 20% of the measured UVA exposures for the cases of cloud with the sun not obscured. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. [Intervention of nicotinamide on skin melanin genesis after UVA exposed].

    PubMed

    Patam, Muhammad; Jin, Xi-peng; Zhang, Yu-bin; Pan, Jian-ying; Shen, Guang-zu

    2007-08-01

    To investigate the interference effect of nicotinamide on UVA-induced melanin genesis and melanin transport in human skin melanocyte. The optimum UVA dose expected to cause cell proliferation: 0.2 J/cm(2), nicotinamide was added immediately after the 0.2 J/cm(2) UVA exposure and the melanin content, cell cycles, cell apoptosis and mRNA express level were measured respectively. Melanin content in melanocytes was increased significantly after exposed to 0.2 J/cm(2) UVA. Melanin content in melanocytes was decreased after treatment with 10.0 mmol/ml nicotinamide following UVA exposure, but the cell cycles and the cell apoptosis rate were not significantly altered. mRNA express levels of TYR, TRP-1 were modulated by nicotinamide. Nicotinamide has more effect on decreasing melanin genesis after UVA exposure, nicotinamide also plays a role in modulating the mRNA express of TYR, TRP-1 gene. It is possible to consider nicotinamide as an efficient and safe sun screen to provide a certain level of protection for UVA exposed skin.

  9. 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.

  10. Environmental UVA radiation and eye protection during PUVA therapy.

    PubMed

    Morison, W L; Strickland, P T

    1983-10-01

    Experimental and clinical evidence suggests that patients receiving psoralens plus UVA radiation (PUVA) therapy for the treatment of psoriasis or other skin diseases run the risk of developing cataracts. The total exposure to UVA radiation of these patients has been difficult to quantify because they are exposed to UVA radiation in the environment as well as during PUVA therapy. In our studies, the spectral irradiances of possible environmental sources of UVA radiation (sunlight, daylight and cool white fluorescent bulbs, and incandescent bulbs) were measured and compared to the spectral irradiance of a bank of PUVA bulbs. Sunlight and PUVA bulbs were found to have similar irradiances in the UVA waveband. Window glass reduced the UVA irradiance from sunlight. Artificial sources of illumination had a very low UVA irradiance compared with PUVA bulbs and sunlight. These results indicate that patients should protect their eyes from sunlight both outdoors and indoors after ingestion of psoralens; however, protection from incandescent bulbs or cool white and daylight fluorescent bulbs is much less important, and possibly unnecessary.

  11. 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.

  12. A review of UVA-mediated photosensitivity disorders.

    PubMed

    Smith, E; Kiss, F; Porter, R M; Anstey, A V

    2012-01-01

    A number of skin conditions are characterised by photosensitivity to UVA. Some of these are exclusively UVA-mediated conditions, while others include UVA in the action spectrum which also include UVB and/or visible light. This review aims to describe this diverse range of conditions for non-dermatologist scientists with an interest in this topic. As such, clinical details, including treatments, are brief and succinct. Recent advances in understanding the pathogenesis of these conditions is highlighted. This journal is © The Royal Society of Chemistry and Owner Societies 2012

  13. UVA/UVA1 phototherapy and PUVA photochemotherapy in connective tissue diseases and related disorders: a research based review

    PubMed Central

    Breuckmann, Frank; Gambichler, Thilo; Altmeyer, Peter; Kreuter, Alexander

    2004-01-01

    Background Broad-band UVA, long-wave UVA1 and PUVA treatment have been described as an alternative/adjunct therapeutic option in a number of inflammatory and malignant skin diseases. Nevertheless, controlled studies investigating the efficacy of UVA irradiation in connective tissue diseases and related disorders are rare. Methods Searching the PubMed database the current article systematically reviews established and innovative therapeutic approaches of broad-band UVA irradiation, UVA1 phototherapy and PUVA photochemotherapy in a variety of different connective tissue disorders. Results Potential pathways include immunomodulation of inflammation, induction of collagenases and initiation of apoptosis. Even though holding the risk of carcinogenesis, photoaging or UV-induced exacerbation, UVA phototherapy seems to exhibit a tolerable risk/benefit ratio at least in systemic sclerosis, localized scleroderma, extragenital lichen sclerosus et atrophicus, sclerodermoid graft-versus-host disease, lupus erythematosus and a number of sclerotic rarities. Conclusions Based on the data retrieved from the literature, therapeutic UVA exposure seems to be effective in connective tissue diseases and related disorders. However, more controlled investigations are needed in order to establish a clear-cut catalogue of indications. PMID:15380024

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. Fluid flow dynamics in MAS systems

    NASA Astrophysics Data System (ADS)

    Wilhelm, Dirk; Purea, Armin; Engelke, Frank

    2015-08-01

    The turbine system and the radial bearing of a high performance magic angle spinning (MAS) probe with 1.3 mm-rotor diameter has been analyzed for spinning rates up to 67 kHz. We focused mainly on the fluid flow properties of the MAS system. Therefore, computational fluid dynamics (CFD) simulations and fluid measurements of the turbine and the radial bearings have been performed. CFD simulation and measurement results of the 1.3 mm-MAS rotor system show relatively low efficiency (about 25%) compared to standard turbo machines outside the realm of MAS. However, in particular, MAS turbines are mainly optimized for speed and stability instead of efficiency. We have compared MAS systems for rotor diameter of 1.3-7 mm converted to dimensionless values with classical turbomachinery systems showing that the operation parameters (rotor diameter, inlet mass flow, spinning rate) are in the favorable range. This dimensionless analysis also supports radial turbines for low speed MAS probes and diagonal turbines for high speed MAS probes. Consequently, a change from Pelton type MAS turbines to diagonal turbines might be worth considering for high speed applications. CFD simulations of the radial bearings have been compared with basic theoretical values proposing considerably smaller frictional loss values. The discrepancies might be due to the simple linear flow profile employed for the theoretical model. Frictional losses generated inside the radial bearings result in undesired heat-up of the rotor. The rotor surface temperature distribution computed by CFD simulations show a large temperature gradient over the rotor.

  19. Fluid flow dynamics in MAS systems.

    PubMed

    Wilhelm, Dirk; Purea, Armin; Engelke, Frank

    2015-08-01

    The turbine system and the radial bearing of a high performance magic angle spinning (MAS) probe with 1.3mm-rotor diameter has been analyzed for spinning rates up to 67kHz. We focused mainly on the fluid flow properties of the MAS system. Therefore, computational fluid dynamics (CFD) simulations and fluid measurements of the turbine and the radial bearings have been performed. CFD simulation and measurement results of the 1.3mm-MAS rotor system show relatively low efficiency (about 25%) compared to standard turbo machines outside the realm of MAS. However, in particular, MAS turbines are mainly optimized for speed and stability instead of efficiency. We have compared MAS systems for rotor diameter of 1.3-7mm converted to dimensionless values with classical turbomachinery systems showing that the operation parameters (rotor diameter, inlet mass flow, spinning rate) are in the favorable range. This dimensionless analysis also supports radial turbines for low speed MAS probes and diagonal turbines for high speed MAS probes. Consequently, a change from Pelton type MAS turbines to diagonal turbines might be worth considering for high speed applications. CFD simulations of the radial bearings have been compared with basic theoretical values proposing considerably smaller frictional loss values. The discrepancies might be due to the simple linear flow profile employed for the theoretical model. Frictional losses generated inside the radial bearings result in undesired heat-up of the rotor. The rotor surface temperature distribution computed by CFD simulations show a large temperature gradient over the rotor. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. MAS-NMR at very high temperatures.

    PubMed

    van Wüllen, Leo; Schwering, Georg; Naumann, Ernst; Jansen, Martin

    2004-09-01

    We report MAS-NMR experiments at temperatures of approx. 1200 K using a CO(2) laser as the heating device. An internal NMR thermometer based on the (7)Li T1 data of Li(0.24)La(0.54)TiO(3) is used for temperature calibration. Using this setup, temperatures as high as 1191 K could be reached under MAS conditions as confirmed by the melting of Li(2)B(4)O(7) at 1191 K which could be followed by (7)Li-MAS-NMR.

  1. MAS NMR of HIV-1 protein assemblies

    NASA Astrophysics Data System (ADS)

    Suiter, Christopher L.; Quinn, Caitlin M.; Lu, Manman; Hou, Guangjin; Zhang, Huilan; Polenova, Tatyana

    2015-04-01

    The negative global impact of the AIDS pandemic is well known. In this perspective article, the utility of magic angle spinning (MAS) NMR spectroscopy to answer pressing questions related to the structure and dynamics of HIV-1 protein assemblies is examined. In recent years, MAS NMR has undergone major technological developments enabling studies of large viral assemblies. We discuss some of these evolving methods and technologies and provide a perspective on the current state of MAS NMR as applied to the investigations into structure and dynamics of HIV-1 assemblies of CA capsid protein and of Gag maturation intermediates.

  2. The effects of UVA-I (340-400 nm), UVA-II (320-340 nm) and UVA-I+II on the photoisomerization of urocanic acid in vivo.

    PubMed

    Webber, L J; Whang, E; De Fabo, E C

    1997-10-01

    Ultraviolet B radiation (280-320 nm) can systemically suppress contact hypersensitivity (CHS), delayed type hypersensitivity (DTH) and tumor rejection responses in mice. Several models have been postulated for the initiation of this UVB-induced immune suppression and, although the complete mechanism is unclear, our early studies suggested that initiation is via the activation of a photoreceptor in the skin, identified as urocanic acid (UCA). Recent preliminary data from our laboratory and others indicated that UVA (320-400 nm)-emitting broad-band sunlamps can also isomerize UCA but may not lead to immune suppression, in contrast to UVB-emitting sunlamps, which cause both effects. Although the reason for this inconsistency is unknown, the emission spectra of UVA lamps contain differing amounts of UVB, UVA-I (340-400 nm) and UVA-II (320-340 nm) from those of UVB sources. In this study we determined a detailed dose-response for the isomerization of UCA in mouse skin using the UVA-I, UVA-II and UVA-I+II wavelength ranges. The dose-response curves obtained were put on an equal energy basis by quantum correction and the possibility of wavelength interaction for this effect investigated. A simple additive wavelength interaction between UVA-I, UVA-II, and UVA-I+II was observed for trans-UCA photoisomerization. This result indicates that the failure of UVA-I, UVA-II or UVA-I+II radiation to induce immune suppression of the CHS response in an animal model is not due to complex wavelength interactions and/or the presence of an in vivo endogenous photosensitizer of UCA isomerization. Other factors, such as downstream blocking by UVA of the cis-UCA generated signal, may be involved.

  3. Millimeter-Wave Atmospheric Sounder (MAS)

    NASA Technical Reports Server (NTRS)

    Hartmann, G. K.

    1988-01-01

    MAS is a remote sensing instrument for passive sounding (limb sounding) of the earth's atmosphere from the Space Shuttle. The main objective of the MAS is to study the composition and dynamic structure of the stratosphere, mesosphere, and lower thermosphere in the height range 20 to 100 km, the region known as the middle atmosphere. The MAS will be flown on the Atmospheric Laboratory for Applications and Science (ATLAS 1) NASA mission scheduled for late 1990. The Millimeter-Wave Atmospheric Sounder will provide, for the first time, information obtained simultaneously on the temperature and on ozone concentrations in the 20 to 90 km altitude region. The information will cover a large area of the globe, will have high accuracy and high vertical resolution, and will cover both day and night times. Additionally, data on the two important molecules, H2O and ClO, will also be provided.

  4. 48 CFR 538.271 - MAS contract awards.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false MAS contract awards. 538... Schedules 538.271 MAS contract awards. (a) MAS awards will be for commercial items as defined in FAR 2.101. Negotiate contracts as a discount from established catalog prices. (b) Before awarding any MAS contract...

  5. Mas' Making and Pedagogy: Imagined Possibilities

    ERIC Educational Resources Information Center

    Fournillier, Janice B.

    2009-01-01

    In this article I draw on an ethnographic case study that examined mas' makers' perceptions of the learning/teaching practices at work in the production of costumes for Trinidad and Tobago's annual Carnival celebrations. During the 2005 Carnival season I spent four months in the field, my country of birth, and collected data through participant…

  6. Mas' Making and Pedagogy: Imagined Possibilities

    ERIC Educational Resources Information Center

    Fournillier, Janice B.

    2009-01-01

    In this article I draw on an ethnographic case study that examined mas' makers' perceptions of the learning/teaching practices at work in the production of costumes for Trinidad and Tobago's annual Carnival celebrations. During the 2005 Carnival season I spent four months in the field, my country of birth, and collected data through participant…

  7. Riboflavin/UVA photochemical therapy for severe infectious keratitis.

    PubMed

    Skaat, Alon; Zadok, David; Goldich, Yakov; Varssano, David; Berger, Yoav; Ezra-Nimni, Orit; Avni, Isaac; Barequet, Irina S

    2014-01-01

    To describe the antibacterial activity of treatment with riboflavin and ultraviolet A light (UVA) in cases of severe infectious keratitis. A retrospective analysis was performed of an interventional case series in which 6 eyes of 6 patients with severe infectious keratitis, all of whom were refractive to multidrug conventional therapy, were treated with riboflavin/UVA. The procedure was conducted according to the standardized protocol of corneal collagen crosslinking (CXL) for keratoconus. Best spectacle-corrected visual acuity and clinical outcomes were evaluated before and during the follow-up period. Five of the 6 patients showed rapid reduction in symptoms and decreased infiltrate size after riboflavin/UVA photochemical therapy. Signs of infection and inflammation mostly resolved within 1 to 2 weeks after the treatment. Despite this therapy, one patient continued to deteriorate, and penetrating keratoplasty was performed. The adjunctive use of riboflavin/UVA photochemical therapy has a positive effect on refractory infectious keratitis. The treatment seems to be safe and effective and should be considered as part of the first-line therapy in severe cases of infectious keratitis.

  8. DNA repair inhibition by UVA photoactivated fluoroquinolones and vemurafenib.

    PubMed

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

    2014-12-16

    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. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

  9. 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

  10. 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.

  11. 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.

  12. Comparison of DNA damage responses following equimutagenic doses of UVA and UVB: a less effective cell cycle arrest with UVA may render UVA-induced pyrimidine dimers more mutagenic than UVB-induced ones.

    PubMed

    Rünger, Thomas M; Farahvash, Benyamin; Hatvani, Zsofia; Rees, Adam

    2012-01-01

    Mechanisms of UVA-mutagenesis remain a matter of debate. Earlier described higher rates of mutation formation per pyrimidine dimer with UVA than with UVB and other evidence suggested that a non-pyrimidine dimer-type of DNA damage contributes more to UVA- than to UVB-mutagenesis. However, more recently published data on the spectra of UVA-induced mutations in primary human skin cells and in mice suggest that pyrimidine dimers are the most common type of DNA damage-inducing mutations not only with UVB, but also with UVA. As this rebuts a prominent role of non-dimer type of DNA damage in UVA-mutagenesis, we hypothesized that the higher mutation rate at UVA-induced pyrimidine dimers, as compared to UVB-induced ones, is caused by differences in the way UVA- and UVB-exposed cells process DNA damage. Therefore, we here compared cell cycle regulation, DNA repair, and apoptosis in primary human fibroblasts following UVB- and UVA-irradiation, using the same physiologic and roughly equimutagenic doses (100-300 J m(-2) UVB, 100-300 kJ m(-2) UVA) we have used previously for mutagenesis experiments with the same type of cells. ELISAs for the detection of pyrimidine dimers confirmed that much fewer dimers were formed with these doses of UVA, as compared to UVB. We found that cell cycle arrests (intra-S, G1/S, G2/M), mediated at least in part by activation of p53 and p95, are much more prominent and long-lasting with UVB than with UVA. In contrast, no prominent differences were found between UVA and UVB for other anti-mutagenic cellular responses (DNA repair, apoptosis). Our data suggest that less effective anti-mutagenic cellular responses, in particular different and shorter-lived cell cycle arrests, render pyrimidine dimers induced by UVA more mutagenic than pyrimidine dimers induced by UVB. This journal is © The Royal Society of Chemistry and Owner Societies 2012

  13. Angiotensin (1-7) induces MAS receptor internalization.

    PubMed

    Gironacci, Mariela M; Adamo, Hugo P; Corradi, Gerardo; Santos, Robson A; Ortiz, Pablo; Carretero, Oscar A

    2011-08-01

    Angiotensin (Ang) (1-7) is the endogenous ligand for the G protein-coupled receptor Mas, a receptor associated with cardiac, renal, and cerebral protective responses. Physiological evidence suggests that Mas receptor (MasR) undergoes agonist-dependent desensitization, but the underlying molecular mechanism regulating receptor activity is unknown. We investigated the hypothesis that MasR desensitizes and internalizes on stimulation with Ang-(1-7). For this purpose, we generated a chimera between the MasR and the yellow fluorescent protein (YFP; MasR-YFP). MasR-YFP-transfected HEK 293T cells were incubated with Ang-(1-7), and the relative cellular distribution of MasR-YFP was observed by confocal microscopy. In resting cells, MasR-YFP was mostly localized to the cell membrane. Ang-(1-7) induced a redistribution of MasR-YFP to intracellular vesicles of various sizes after 5 minutes. Following the time course of [(125)I]Ang-(1-7) endocytosis, we observed that half of MasR-YFP underwent endocytosis after 10 minutes, and this was blocked by a MasR antagonist. MasR-YFP colocalized with Rab5, the early endosome antigen 1, and the adaptor protein complex 2, indicating that the R is internalized through a clathrin-mediated pathway and targeted to early endosomes after Ang-(1-7) stimulation. A fraction of MasR-YFP also colocalized with caveolin 1, suggesting that at some point MasR-YFP traverses caveolin 1-positive compartments. In conclusion, MasR undergoes endocytosis on stimulation with Ang-(1-7), and this event may explain the desensitization of MasR responsiveness. In this way, MasR activity and density may be tightly controlled by the cell.

  14. Ultra-low temperature MAS-DNP

    NASA Astrophysics Data System (ADS)

    Lee, Daniel; Bouleau, Eric; Saint-Bonnet, Pierre; Hediger, Sabine; De Paëpe, Gaël

    2016-03-01

    Since the infancy of NMR spectroscopy, sensitivity and resolution have been the limiting factors of the technique. Regular essential developments on this front have led to the widely applicable, versatile, and powerful spectroscopy that we know today. However, the Holy Grail of ultimate sensitivity and resolution is not yet reached, and technical improvements are still ongoing. Hence, high-field dynamic nuclear polarization (DNP) making use of high-frequency, high-power microwave irradiation of electron spins has become very promising in combination with magic angle sample spinning (MAS) solid-state NMR experiments. This is because it leads to a transfer of the much larger polarization of these electron spins under suitable irradiation to surrounding nuclei, greatly increasing NMR sensitivity. Currently, this boom in MAS-DNP is mainly performed at minimum sample temperatures of about 100 K, using cold nitrogen gas to pneumatically spin and cool the sample. This Perspective deals with the desire to improve further the sensitivity and resolution by providing "ultra"-low temperatures for MAS-DNP, using cryogenic helium gas. Different designs on how this technological challenge has been overcome are described. It is shown that stable and fast spinning can be attained for sample temperatures down to 30 K using a large cryostat developed in our laboratory. Using this cryostat to cool a closed-loop of helium gas brings the additional advantage of sample spinning frequencies that can greatly surpass those achievable with nitrogen gas, due to the differing fluidic properties of these two gases. It is shown that using ultra-low temperatures for MAS-DNP results in substantial experimental sensitivity enhancements and according time-savings. Access to this temperature range is demonstrated to be both viable and highly pertinent.

  15. The impact of natural sunlight exposure on the UVB-sun protection factor (UVB-SPF) and UVA protection factor (UVA-PF) of a UVA/UVB SPF 50 sunscreen.

    PubMed

    Stephens, Thomas J; Herndon, James H; Colón, Luz E; Gottschalk, Ronald W

    2011-02-01

    To compare the functional stability of Cetaphil UVA/UVB Defense SPF 50 as measured by its ultraviolet B sun protection factor (UVB-SPF) and ultraviolet A protection factor (UVA-PF) values following exposure to natural sunlight versus the UVB-SPF and UVA-PF values of unexposed product. These two randomized, controlled, evaluator-blinded, single-center trials were conducted according to the methods outlined in the 2007 Proposed Amendment to the Final Monograph, “Sunscreen Drug Products for Over-the-Counter Human Use.” Sunscreen samples were applied to glass plates and exposed to ultraviolet radiation in the form of natural sunlight in four minimal erythemal doses (MED) ranging from 2–6 MED (42–36 mJ/cm2). Three test sites were identified on the back of each study subject. Exposed sunscreen (one of four doses), unexposed sunscreen, and a UVB-SPF 15 control sunscreen were applied to the three test sites in a randomized fashion, followed by UV irradiation of incremental doses. Erythema and pigment darkening responses were assessed immediately following UV exposure and again 16–24 hours (erythema) or three to 24 hours (pigment darkening) after exposure. UVB-SPF and UVA-PF values were calculated for the exposed and unexposed samples. The calculated UVB-SPF and UVA-PF values for all test samples (exposed and unexposed) were >50 and >9, respectively, which were greater than the stated UVB-SPF and UVA-PF values on the product label. No differences were observed between the exposed and unexposed samples in UVB-SPF or UVA-PF. The UVA and UVB protection using standard evaluation techniques of Cetaphil UVA/UVB Defense SPF 50 remains stable despite exposure of the sunscreen to natural sunlight containing UVB ranging from 2–16 MED (41–336 mJ/cm2) and coexistent UVA.

  16. In vitro assessments of UVA protection by popular sunscreens available in the United States.

    PubMed

    Wang, Steven Q; Stanfield, Joseph W; Osterwalder, Uli

    2008-12-01

    The importance of adequate ultraviolet A (UVA) protection has become apparent with improved understanding of the mechanism of UVA-induced damage to tissues. Currently in the United States, there is no regulation on testing and labeling of sunscreens for UVA protection. In August 2007, the Food and Drug Administration (FDA) addressed this issue in a proposed rule. We sought to assess in vitro the degree of UVA protection provided by 13 popular sunscreen products that are commercially available in the United States. Thirteen sunscreen products were purchased. UVA protection of each product was measured and assessed with 3 in vitro UVA labeling indices: (1) the FDA Proposed Amendment of Final Monograph, August 27, 2007; (2) European Commission Recommendation--the Colipa and critical wavelength methods; (3) and United Kingdom's Boots star rating system. Based on the new FDA-proposed guidelines, 8 products achieved the medium protection category, and 5 products achieved high protection. The latter 5 products also fulfilled the UVA protection based on the Colipa guideline desired by the European Commission Recommendation. Nine products achieved the desired critical wavelength value of 370 or higher. Based on the United Kingdom's Boots star rating system, 6 products achieved a rating of 3 stars, and the remaining 7 products achieved no star rating. The study only evaluated a small number of sunscreen products, and only in vitro methods were used to assess the degree of UVA protection. The majority of the tested sunscreens in this study offered a medium degree of UVA protection. Compared with the sunscreens in the past, this study shows that UVA protection of sunscreens has improved. Sunscreens with avobenzone and octocrylene provided a higher degree of UVA protection. Globally, there is no uniform standard on testing and labeling sunscreens for UVA protection. In the United States, the FDA has just started to create a much-needed standard. This effort is necessary to

  17. The Evaluation of Corneal Fragility After UVA/Riboflavin Crosslinking.

    PubMed

    Li, Zhiwei; Wang, Yumeng; Xu, Yanyun; Jhanji, Vishal; Zhang, Chunxiao; Mu, Guoying

    2017-03-01

    To evaluate the fragility of cornea after UVA/riboflavin crosslinking (CXL). Sixty New Zealand rabbits received UVA/riboflavin crosslinking treatment (wavelength 365 nm, irradiance 3.0 mW/cm, and total dose 5.4 J/cm) on right eyes. Animals were sacrificed before and immediately after treatment (day 0), day 1, 3, 7, and 28 after treatment. A 4×10 mm corneal strip for biomechanical evaluation was harvested after sacrifice. The corneal fragility was evaluated by measurement of elongation rate, whereby the elongation rate equals elongation length/baseline length. The Youngs modulus and maximal stress were 1.41±0.51 MPa and 5.56±1.84 MPa before CXL, and increased to 2.31±0.68 MPa (P=0.008) and 9.25±2.74 MPa (P=0.04), respectively, on day 0, then maintained a stable level within a 28 days follow-up. The elongation rate was 62.04±9.34% before CXL and decreased to 48.95%±8.24% (P=0.02) on day 0, then maintained a stable level within a 28 days follow-up. This study showed an increase in the corneal fragility after UVA/riboflavin crosslinking along with an increase in the corneal stiffness. A long-term follow-up should be taken to evaluate the potential deleterious effect of the increasing corneal fragility after UVA/riboflavin crosslinking.

  18. 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

  19. 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.

  20. Sensing and Responding to UV-A in Cyanobacteria

    PubMed Central

    Moon, Yoon-Jung; Kim, Seung Il; Chung, Young-Ho

    2012-01-01

    Ultraviolet (UV) radiation can cause stresses or act as a photoregulatory signal depending on its wavelengths and fluence rates. Although the most harmful effects of UV on living cells are generally attributed to UV-B radiation, UV-A radiation can also affect many aspects of cellular processes. In cyanobacteria, most studies have concentrated on the damaging effect of UV and defense mechanisms to withstand UV stress. However, little is known about the activation mechanism of signaling components or their pathways which are implicated in the process following UV irradiation. Motile cyanobacteria use a very precise negative phototaxis signaling system to move away from high levels of solar radiation, which is an effective escape mechanism to avoid the detrimental effects of UV radiation. Recently, two different UV-A-induced signaling systems for regulating cyanobacterial phototaxis were characterized at the photophysiological and molecular levels. Here, we review the current understanding of the UV-A mediated signaling pathways in the context of the UV-A perception mechanism, early signaling components, and negative phototactic responses. In addition, increasing evidences supporting a role of pterins in response to UV radiation are discussed. We outline the effect of UV-induced cell damage, associated signaling molecules, and programmed cell death under UV-mediated oxidative stress. PMID:23208372

  1. 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.

  2. 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.

  3. Evaluating UVA aerosol optical depth using a smartphone camera.

    PubMed

    Igoe, Damien P; Parisi, Alfio V; Carter, Brad

    2013-01-01

    This research evaluates a smartphone complementary metal oxide semiconductor (CMOS) image sensor's ability to detect and quantify incident solar UVA radiation and subsequently, aerosol optical depth at 340 and 380 nm. Earlier studies revealed that the consumer grade CMOS sensor has inherent UVA sensitivities, despite attenuating effects of the lens. Narrow bandpass and neutral density filters were used to protect the image sensor and to not allow saturation of the solar images produced. Observations were made on clear days, free from clouds. The results of this research demonstrate that there is a definable response to changing solar irradiance and aerosol optical depth can be measured within 5% and 10% error margins at 380 and 340 nm respectively. The greater relative error occurs at lower wavelengths (340 nm) due to increased atmospheric scattering effects, particularly at higher air masses and due to lower signal to noise ratio in the image sensor. The relative error for solar irradiance was under 1% for observations made at 380 nm. The results indicate that the smartphone image sensor, with additional external narrow bandpass and neutral density filters can be used as a field sensor to evaluate solar UVA irradiance and aerosol optical depth. © 2013 The American Society of Photobiology.

  4. 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.

  5. Daily variation of UV-A and UV-B solar radiation on the Adriatic Sea.

    PubMed

    Vojniković, Bozo; Toth, Ivan

    2011-09-01

    During the summer months, from June thru September, in Opatija and island of Rab area, we conducted UVA and UVB measurements using a professional detector: Solar Light Co., Inc. USA. Ordering: PMA2110 UV-A and PMA2101 UV-B detector. We conducted global UVA and UVB measurements in the 2006 to 2011 period. Results of the measurements show June to September daily, 10 am to 3 pm, UVA and UVB variations to be above allowed values especially in the maritime area. The measurements were performed in cooperation with "Dr. B. Vojniković" Daily eye clinic and the University of Applied Sciences Velika Gorica, Velika Gorica, Croatia.

  6. UVA-photoactivated riboflavin effect on isolated vaginal tissues derived from pelvic organ prolapse cases.

    PubMed

    McMillan, Kimberly S; Siddighi, Sam; Hardesty, Jeffrey S; Yune, Joshua J; Chan, Philip J

    2015-01-01

    To determine the optimal riboflavin exposure time before UVA irradiation and to study the effects of exogenous collagen on the mechano-tensile stiffness of isolated vaginal tissue strips after riboflavin UVA photoactivation. Vaginal tissue strips from pelvic organ prolapse (POP) cases were soaked in 0.1% riboflavin (0, 10, 20, 30 min), exposed to UVA photoactivation, and tensile stiffness was measured with a tensiometer. Collagen solution was injected (0.2 mL) into each strip, exposed to riboflavin with or without UVA photoactivation, and tensile stiffness was measured (n=6). Vaginal tissues treated with riboflavin for 10, 20 or 30 min followed by UVA irradiation displayed 21.2, 32.4 and 33.9% stronger tensile stiffness, respectively. Exogenous collagen administered before riboflavin UVA photoactivation resulted in 20% improvement in tensile stiffness. The tensile stiffness of vaginal tissues injected with collagen without the riboflavin UVA treatment was similar to control tissues. The results demonstrated increased tensile stiffness in isolated POP-derived vaginal tissues after riboflavin UVA photoactivation suggesting improved mechanical properties from collagen cross-linking. Administering exogenous collagen before riboflavin UVA treatment also improved tensile stiffness. More studies are needed to corroborate the present minimally invasive approach for strengthening vaginal tissues.

  7. Long-term UVA eye irradiation causes decreased learning ability in mice.

    PubMed

    Hiramoto, Keiichi; Kasahara, Emiko

    2016-05-01

    Long-term eye radiation with ultraviolet A (UVA) denatures the cells of the cerebral hippocampus. However, the influence on memory and learning ability in mice is not known. HR-1 mice were used. We irradiated the eyes or dorsal skin of the mice with UVA at a dose of 110 kJ/m(2) using an FL20SBLB-A lamp for 6, 12, and 24 months. The mean escape latency in the water maze was significantly increased in the UVA-irradiated mice in comparison with that seen in the controls. In the mice in which UVA eye irradiation was performed for 24 months, the depression of memory and learning ability was remarkable. The acetylcholinesterase activity, choline acetyltransferase activity, and acetylcholine content in the brain in the UVA eye-irradiated mice were significantly less than those observed in the control mice. Furthermore, during UVA eye irradiation, the levels of β-amyloid (Aβ), γ-secretase, which produces Aβ peptide, and advanced glycation end products increased. Moreover, the effects of UVA eye irradiation increased with the duration of irradiation (or aging), and the introduction of glucose into the brain also decreased with UVA eye irradiation. These results indicate that UVA eye irradiation induces a decreased memory and learning ability in mice. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  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. Adaptor protein p62 promotes skin tumor growth and metastasis and is induced by UVA radiation.

    PubMed

    Sample, Ashley; Zhao, Baozhong; Qiang, Lei; He, Yu-Ying

    2017-09-08

    Skin cancer is the most common cancer, and exposure to ultraviolet (UV) radiation, namely UVA and UVB, is the major risk factor for skin cancer development. UVA is significantly less effective in causing direct DNA damage than UVB, but UVA has been shown to increase skin cancer risk. The mechanism by which UVA contributes to skin cancer remains unclear. Here, using RNA-Seq, we show that UVA induces autophagy and lysosomal gene expression, including the autophagy receptor and substrate p62. We found that UVA activates transcription factor EB (TFEB), a known regulator of autophagy and lysosomal gene expression, which, in turn, induces p62 transcription. Next, we identified a novel relationship between p62 and cyclooxygenase-2 (COX-2), a prostaglandin synthase critical for skin cancer development. COX-2 expression was up-regulated by UVA-induced p62, suggesting that p62 plays a role in UVA-induced skin cancer. Moreover, we found that p62 stabilizes COX-2 protein through the p62 ubiquitin-associated domain and that p62 regulates prostaglandin E2 production in vitro In a syngeneic squamous cell carcinoma mouse model, p62 knockdown inhibited tumor growth and metastasis. Furthermore, p62-deficient tumors exhibited reduced immune cell infiltration and increased cell differentiation. Because prostaglandin E2 is known to promote pro-tumorigenic immune cell infiltration, increase proliferation, and inhibit keratinocyte differentiation in vivo, this work suggests that UVA-induced p62 acts through COX-2 to promote skin tumor growth and progression. These findings expand our understanding of UVA-induced skin tumorigenesis and tumor progression and suggest that targeting p62 can help prevent or treat UVA-associated skin cancer. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  15. 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.

  16. 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.

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

    DTIC Science & Technology

    2014-09-01

    fibroblasts and determine if bystander oxidative stress is induced by UVA irradiation and abrogated by antioxidants . In initial studies, we selected...primary human skin cells in order to avoid untoward effects of immortalization or transformation. Initial experiments determined direct effects...of UVA on normal human melanocytes (NHMs), fibroblasts (NHFs) and keratinocytes (NHKs). Figure 1A shows dose- dependent toxicity for three skin

  18. 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.

  19. 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.

  20. UV-A radiation effects on higher plants: Exploring the known unknown.

    PubMed

    Verdaguer, Dolors; Jansen, Marcel A K; Llorens, Laura; Morales, Luis O; Neugart, Susanne

    2017-02-01

    Ultraviolet-A radiation (UV-A: 315-400nm) is a component of solar radiation that exerts a wide range of physiological responses in plants. Currently, field attenuation experiments are the most reliable source of information on the effects of UV-A. Common plant responses to UV-A include both inhibitory and stimulatory effects on biomass accumulation and morphology. UV-A effects on biomass accumulation can differ from those on root: shoot ratio, and distinct responses are described for different leaf tissues. Inhibitory and enhancing effects of UV-A on photosynthesis are also analysed, as well as activation of photoprotective responses, including UV-absorbing pigments. UV-A-induced leaf flavonoids are highly compound-specific and species-dependent. Many of the effects on growth and development exerted by UV-A are distinct to those triggered by UV-B and vary considerably in terms of the direction the response takes. Such differences may reflect diverse UV-perception mechanisms with multiple photoreceptors operating in the UV-A range and/or variations in the experimental approaches used. This review highlights a role that various photoreceptors (UVR8, phototropins, phytochromes and cryptochromes) may play in plant responses to UV-A when dose, wavelength and other conditions are taken into account. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  1. 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.

  2. Solar or UVA-Visible Photocatalytic Ozonation of Water Contaminants.

    PubMed

    Beltrán, Fernando J; Rey, Ana

    2017-07-14

    An incipient advanced oxidation process, solar photocatalytic ozonation (SPO), is reviewed in this paper with the aim of clarifying the importance of this process as a more sustainable water technology to remove priority or emerging contaminants from water. The synergism between ozonation and photocatalytic oxidation is well known to increase the oxidation rate of water contaminants, but this has mainly been studied in photocatalytic ozonation systems with lamps of different radiation wavelength, especially of ultraviolet nature (UVC, UVB, UVA). Nowadays, process sustainability is critical in environmental technologies including water treatment and reuse; the application of SPO systems falls into this category, and contributes to saving energy and water. In this review, we summarized works published on photocatalytic ozonation where the radiation source is the Sun or simulated solar light, specifically, lamps emitting radiation to cover the UVA and visible light spectra. The main aspects of the review include photoreactors used and radiation sources applied, synthesis and characterization of catalysts applied, influence of main process variables (ozone, catalyst, and pollutant concentrations, light intensity), type of water, biodegradability and ecotoxicity, mechanism and kinetics, and finally catalyst activity and stability.

  3. Computational structures technology and UVA Center for CST

    NASA Technical Reports Server (NTRS)

    Noor, Ahmed K.

    1992-01-01

    Rapid advances in computer hardware have had a profound effect on various engineering and mechanics disciplines, including the materials, structures, and dynamics disciplines. A new technology, computational structures technology (CST), has recently emerged as an insightful blend between material modeling, structural and dynamic analysis and synthesis on the one hand, and other disciplines such as computer science, numerical analysis, and approximation theory, on the other hand. CST is an outgrowth of finite element methods developed over the last three decades. The focus of this presentation is on some aspects of CST which can impact future airframes and propulsion systems, as well as on the newly established University of Virginia (UVA) Center for CST. The background and goals for CST are described along with the motivations for developing CST, and a brief discussion is made on computational material modeling. We look at the future in terms of technical needs, computing environment, and research directions. The newly established UVA Center for CST is described. One of the research projects of the Center is described, and a brief summary of the presentation is given.

  4. 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.

  5. Broad-spectrum moisturizer effectively prevents molecular reactions to UVA radiation.

    PubMed

    Seité, Sophie; Reinhold, Katja; Jaenicke, Thomas; Brenden, Heidi; Krutmann, Jean; Grether-Beck, Susanne

    2012-12-01

    The damaging effects of UVA radiation have been well-documented. UVA radiation is known to induce molecular, cellular, and clinical damage. Such harm may lead to photoaging, immune system depression, altered gene expression, or oncogene and tumor suppressor gene modulation, all of which are partly responsible for the development of skin cancer. In parallel to an increased understanding of the added damage caused by UVA radiation, progress has been made in sunscreen formulation. A variety of UVA filters are now available for formulators to combine with UVB filters to reach high-level photostable protection using a minimum concentration of active ingredients. The efficacy of products that contain these UV filter combinations usually is determined by noninvasive assessments, which cause either UVA-induced erythema or skin pigmentation. However, the biologic relevance of these end points for UVA radiation-induced skin damage is unknown. In our study, we confirm that the assessment of UVA radiation-induced gene expression in skin specimens obtained from UVA-irradiated human skin by quantitative real-time polymerase chain reaction is a sensitive, reliable, and robust method to prove the efficacy of 2 daily moisturizers containing broad-spectrum sunscreen. Specifically, we demonstrate in vivo that topical application of a daily moisturizer with broad-spectrum sunscreen prevents UVA radiation-induced transcriptional expression of genes that are directly linked to skin aging (ie, matrix metalloproteinase 1 [MMP-1]) and also reflect the skin's antioxidative stress defense response (ie, catalase [CAT], superoxide dismutase [SOD], glutathione peroxidase [GPx]). Furthermore, we demonstrate that the protection against UV-induced skin damage provided by products with different sun protection factor (SPF) but the same UVA protection factor (UVA-PF) is similar, which emphasizes the importance of high UVA protection to maintain unaltered essential biologic functions. These data

  6. Protective effect of UV-A radiation during acclimation of the photosynthetic apparatus to UV-B treatment.

    PubMed

    Štroch, Michal; Materová, Zuzana; Vrábl, Daniel; Karlický, Václav; Šigut, Ladislav; Nezval, Jakub; Špunda, Vladimír

    2015-11-01

    We examined the acclimation response of the photosynthetic apparatus of barley (Hordeum vulgare L.) to a combination of UV-A and UV-B radiation (UVAB) and to UV-B radiation alone. Our aim was to evaluate whether UV-A radiation prevents UV-B-induced damage to the photosynthetic apparatus and whether UV-A pre-acclimation is required to mitigate the negative influence of UV-B radiation. Barley plants were grown from seeds under low photosynthetically active radiation (50 μmol m(-2) s(-1)) either in the absence or presence of UV-A radiation (UVA- and UVA+ plants, respectively). After 8 days of development, plants were exposed simultaneously to UV-A and UV-B radiation for the next 6 days. Additionally, UVA- plants were exposed to UV-B radiation alone. The UVA+ plants had a higher CO2 assimilation rate near the light-saturation region (A(N)) and a higher content of both total chlorophylls (Chls) and total carotenoids than the UVA- plants. Chls content, A(N), the potential quantum yield of photosystem II (PSII) photochemistry (F(V)/F(M)), the capacity of light-induced thermal energy dissipation and the efficiency of excitation energy transfer within PSII remained the same or even increased in both UVA+ and UVA- plants after UVAB treatment. On the contrary, exposure of UVA- plants to UV-B radiation itself led to a reduction in all these characteristics. We revealed that the presence of UV-A radiation during UVAB treatment not only mitigated but completely eliminated the negative effect of UV-B radiation on the functioning of the photosynthetic apparatus and that UV-A pre-acclimation was not crucial for development of this UV-A-induced resistance against UV-B irradiation. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

  7. 48 CFR 538.272 - MAS price reductions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false MAS price reductions. 538... Schedules 538.272 MAS price reductions. (a) Section 552.238-75, Price Reductions, requires the contractor to maintain during the contract period the negotiated price/discount relationship (and/or term and condition...

  8. 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}.

  9. 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.

  10. [The intervention of nicotinamide on skin melanocyte's cell proliferation after UVA (365 nm) exposed.].

    PubMed

    Patam, Muhammad; Jin, Xi-peng; Pan, Jian-ying; Shen, Guang-zu; Jin, Tai-Yi

    2005-02-01

    To investigate the interference effect of nicotinamide on UVA-induced cell proliferation in human skin melanocyte. To apply the optimum UVA dose expected to cause cell proliferation: 0.2 cm2, nicotinamide was added after the 0.2 cm2 UVA exposure immediately or 48 h later, then the rate of cell proliferation, calcium concentration and the activities of Na+-K+, Ca2+-ATP enzymes of melanocytes were measured respectively. After treatment with 1.000 mg/ml nicotinamide following UVA exposure, the rate of cell proliferation was decreased significantly 24 hours later. Treatment with 0.125 mg/ml nicotinamide 48 hours after UVA exposure also significantly inhibited the cell proliferation; 1.25 mg/ml nicotinamide increased calcium concentration in cells; 0.250 mg/ml nicotinamide increased the activities of Na+-K+, Ca2+-ATP enzymes in melanocytes (P < 0.05). Nicotinamide has more obvious effect on inhibiting melanocyte's proliferation if added immediately following UVA exposure. Our discovery indicated that nicotinamide may affect the melanocyte through modulating the calcium concentration. It is possible to consider nicotinamide as an efficient and safe sun screen to provide a certain level of protection for UVA exposed skin.

  11. 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.

  12. 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.

  13. 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.

  14. 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

  15. 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.

  16. UVA-photoactivated riboflavin treatment of vaginal cells derived from pelvic organ prolapse cases.

    PubMed

    Schultz, Kevin J; Siddighi, Sam; Hardesty, Jeffrey S; Waggonner, David B; Yune, J Joshua; Chan, Philip J

    2014-01-01

    The pathophysiology of pelvic organ prolapse (POP) involves vaginal collagen degradation. Strengthening collagen by UVA-photoactivated cross-linking has been demonstrated and suggested target applications include the vaginal wall. To identify UVA irradiation and riboflavin effects on vaginal cells. Vaginal cells were incubated for 24 h (DMEM/F-12 Ham's media) and were exposed to riboflavin (0, 0.1 and 10%) for 30 min before UVA photoactivation. Percentages of live, apoptotic and necrotic cells were determined by propidium iodide/Hoechst 33342 stains. UVA decreased vaginal cell viability [mean ± standard error of the mean: 26.2 ± 0.5% vs. control (43.9 ± 3.8%)], but riboflavin blocked UVA-induced damage (57.9 ± 2.7 and 56.7 ± 2.1% at 0.1 and 10% riboflavin, respectively). Cells treated with low- and high-dose riboflavin had lower apoptosis (32.9 ± 1.0 and 35.5 ± 0.9%, respectively). Furthermore, riboflavin-treated cells had reduced necrosis (9.3 ± 1.7, 7.8 ± 3.0%) versus UVA-only (32.4 ± 5.5%) or control (17.1 ± 2.8%). Viability was similar for cells from the cervical and hymenal segments. The results demonstrated that riboflavin attenuated UVA damage in vaginal cells by inhibiting necrosis. Cervical and hymenal end vaginal cells were equally affected by UVA. UVA phototoxicity was reduced by the presence of riboflavin. © 2014 S. Karger AG, Basel.

  17. 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.

  18. [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.

  19. Optimization of dental CBCT exposures through mAs reduction.

    PubMed

    Pauwels, R; Seynaeve, L; Henriques, J C G; de Oliveira-Santos, C; Souza, P C; Westphalen, F H; Rubira-Bullen, I R F; Ribeiro-Rotta, R F; Rockenbach, M I B; Haiter-Neto, F; Pittayapat, P; Bosmans, H; Bogaerts, R; Jacobs, R

    2015-01-01

    To investigate the effect of tube current-exposure time (mAs) reduction on clinical and technical image quality for different CBCT scanners, and to determine preliminary minimally acceptable values for the mAs and contrast-to-noise ratio (CNR) in CBCT. A polymethyl methacrylate (PMMA) phantom and an anthropomorphic skull phantom, containing a human skeleton embedded in polyurethane, were scanned using four CBCT devices, including seven exposure protocols. For all protocols, the mAs was varied within the selectable range. Using the PMMA phantom, the CNRAIR was measured and corrected for voxel size. Eight axial slices and one coronal slice showing various anatomical landmarks were selected for each CBCT scan of the skull phantom. The slices were presented to six dentomaxillofacial radiologists, providing scores for various anatomical and diagnostic parameters. A hyperbolic relationship was seen between CNRAIR and mAs. Similarly, a gradual reduction in clinical image quality was seen at lower mAs values; however, for several protocols, image quality remained acceptable for a moderate or large mAs reduction compared with the standard exposure setting, depending on the clinical application. The relationship between mAs, CNRAIR and observer scores was different for each CBCT device. Minimally acceptable values for mAs were between 9 and 70, depending on the criterion and clinical application. Although noise increased at a lower mAs, clinical image quality often remained acceptable at exposure levels below the manufacturer's recommended setting, for certain patient groups. Currently, it is not possible to determine minimally acceptable values for image quality that are applicable to multiple CBCT models.

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

    USDA-ARS?s Scientific Manuscript database

    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)....

  1. UVA-induced erythema, pigmentation, and skin surface temperature changes are irradiance dependent

    SciTech Connect

    Kagetsu, N.; Gange, R.W.; Parrish, J.A.

    1985-11-01

    Human cutaneous erythemogenic and melanogenic responses to long-wave (UVA) ultraviolet radiation were investigated using irradiances ranging from 5-50 mW/cm2. Skin surface temperature changes resulting from the different irradiances were also compared. In general, threshold doses for erythema and pigmentation were higher when UVA was administered at the lowest irradiance (5 mW/cm2) than at the highest (50 mW/cm2). Erythema was maximal immediately after exposure to UVA. The most intense responses (erythema with edema, or intense pigmentation) were induced more frequently by the highest irradiance. Components of both the erythema and the pigment response to UVA are therefore irradiance-dependent. The greatest increase in skin surface temperature was observed after exposure to the highest irradiance.

  2. 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

  3. 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.

  4. 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.

  5. Endothelin-1 downregulates Mas receptor expression in human cardiomyocytes.

    PubMed

    Chen, Zhiheng; Tang, Yamei; Yang, Zuocheng; Liu, Shaojun; Liu, Yong; Li, Yan; He, Wei

    2013-09-01

    Endothelin-1 (ET-1) and the renin-angiotensin system (RAS) are involved in the pathogenesis of cardiac dysfunction. The Mas receptor is a functional binding site for angiotensin (Ang)‑(1-7), which is now considered a critical component of the RAS and exerts cardioprotective effects. To the best of our knowledge, the present study aimed to examine, for the first time, the effects of ET-1 on Mas expression in cultured human cardiomyocytes. Human cardiomyocytes were treated with ET-1 at different concentrations (1, 5, 10, 20 and 30 nM) for varied time periods (0.5, 1.5, 3, 4.5 or 6 h) with or without the transcription inhibitor actinomycin D, endothelin A (ETA) receptor blocker BQ123 and ETB receptor blocker BQ788, or different kinase inhibitors. ET-1 decreased the Mas mRNA level in a statistically significant dose- and time-dependent manner within 4.5 h, which was reflected in the dose-dependent downregulation of Mas promoter activity, Mas protein levels and Ang-(1-7) binding on the cell membrane. Actinomycin D (1 mg/ml), BQ123 (1 µM), p38 mitogen-activated protein kinase (MAPK) siRNA and inhibitor PD169316 (25 µM), completely eliminated the inhibitory effects of ET-1 on Mas expression in human cardiomyocytes. In conclusion, the present study demonstrated that ET-1 downregulates Mas expression at the transcription level in human cardiomyocytes via the ETA receptor by a p38 MAPK‑dependent mechanism. This study provides novel insights into the function of ET-1 and the Ang‑(1-7)/Mas axis in cardiac pathophysiology.

  6. 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.

  7. 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.

  8. 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.

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

    PubMed

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

    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.

  10. 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.

  11. 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

  12. 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.

  13. Broadband Direct UVA irradiance measurement for clear skies evaluated using a smartphone.

    PubMed

    Igoe, D; Parisi, A V

    2015-12-01

    UVA wavelengths (320-400 nm) have been implicated in recent studies to contribute to melanoma induction and skin photoaging in humans and damage to plants. The use of smartphones in UVA observations is a way to supplement measurements made by traditional radiometric and spectroradiometric technology. Although the smartphone image sensor is not capable of determining broadband UVA irradiances, these can be reconstructed from narrowband irradiances, which the smartphone, with narrowband and neutral density filters, can quantify with discrepancies not exceeding 5 %. Three models that reconstruct direct broadband clear sky UVA were developed from narrowband irradiances derived from smartphone image sensor pixel data with coefficients of determination of between 0.97 and 0.99. Reasonable accuracy and precision in determining the direct broadband UVA was maintained for observations made with solar zenith angles as high as 70°. The developed method has the potential to increase the uptake of the measurement of broadband UVA irradiances. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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

    PubMed

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

    2012-08-10

    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. 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.

  16. 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)

  17. 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.

  18. 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.

  19. 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).

  20. 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.

  1. Increased vascular sympathetic modulation in mice with Mas receptor deficiency.

    PubMed

    Rabello Casali, Karina; Ravizzoni Dartora, Daniela; Moura, Marina; Bertagnolli, Mariane; Bader, Michael; Haibara, Andrea; Alenina, Natalia; Irigoyen, Maria Claudia; Santos, Robson A

    2016-01-01

    The angiotensin-converting enzyme 2 (ACE2)/angiotensin (Ang)-(1-7)/Mas axis could modulate the heart rate (HR) and blood pressure variabilities (BPV) which are important predictors of cardiovascular risk and provide information about the autonomic modulation of the cardiovascular system. Therefore we investigated the effect of Mas deficiency on autonomic modulation in wild type and Mas-knockout (KO) mice. Blood pressure was recorded at high sample rate (4000 Hz). Stationary sequences of 200-250 beats were randomly chosen. Frequency domain analysis of HR and BPV was performed with an autoregressive algorithm on the pulse interval sequences and on respective systolic sequences. The KO group presented an increase of systolic arterial pressure (SAP; 127.26±11.20 vs 135.07±6.98 mmHg), BPV (3.54±1.54 vs 5.87±2.12 mmHg(2)), and low-frequency component of systolic BPV (0.12±0.11 vs 0.47±0.34 mmHg(2)). The deletion of Mas receptor is associated with an increase of SAP and with an increased BPV, indicating alterations in autonomic control. Increase of sympathetic vascular modulation in absence of Mas evidences the important role of Ang-(1-7)/Mas on cardiovascular regulation. Moreover, the absence of significant changes in HR and HRV can indicate an adaptation of autonomic cardiac balance. Our results suggest that the Ang-(1-7)/Mas axis seems more important in autonomic modulation of arterial pressure than HR. © The Author(s) 2016.

  2. 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.

  3. Quantitative Assessment of UVA-Riboflavin Corneal Cross-Linking Using Nonlinear Optical Microscopy

    PubMed Central

    Chai, Dongyul; Gaster, Ronald N.; Roizenblatt, Roberto; Juhasz, Tibor; Brown, Donald J.

    2011-01-01

    Purpose. Corneal collagen cross-linking (CXL) by the use of riboflavin and ultraviolet-A light (UVA) is a promising and novel treatment for keratoconus and other ectatic disorders. Since CXL results in enhanced corneal stiffness, this study tested the hypothesis that CXL-induced stiffening would be proportional to the collagen autofluorescence intensity measured with nonlinear optical (NLO) microscopy. Methods. Rabbit eyes (n = 50) were separated into five groups including: (1) epithelium intact; (2) epithelium removed; (3) epithelium removed and soaked in riboflavin, (4) epithelium removed and soaked in riboflavin, with 15 minutes of UVA exposure; and (5) epithelium removed and soaked in riboflavin, with 30 minutes of UVA exposure. Corneal stiffness was quantified by measuring the force required to displace the cornea 500 μm. Corneas were then fixed in paraformaldehyde and sectioned, and the collagen autofluorescence over the 400- to 450-nm spectrum was recorded. Results. There was no significant difference in corneal stiffness among the three control groups. Corneal stiffness was significantly and dose dependently increased after UVA (P < 0.0005). Autofluorescence was detected only within the anterior stroma of the UVA-treated groups, with no significant difference in the depth of autofluorescence between different UVA exposure levels. The signal intensity was also significantly increased with longer UVA exposure (P < 0.001). Comparing corneal stiffness with autofluorescence intensity revealed a significant correlation between these values (R2 = 0.654; P < 0.0001). Conclusions. The results of this study indicate a significant correlation between corneal stiffening and the intensity of collagen autofluorescence after CXL. This finding suggests that the efficacy of CXL in patients could be monitored by assessing collagen autofluorescence. PMID:21508101

  4. Effects of UVA (320-400 nm) on the barrier characteristics of the skin

    SciTech Connect

    McAuliffe, D.J.; Blank, I.H. )

    1991-05-01

    The stratum corneum serves as the major barrier to the entrance of most molecules into the skin. In the studies presented here, the effects of UVA radiation (320-400 nm) on the barrier capacity of human stratum corneum were examined. Penetration of a homologous series of primary alcohols through unirradiated (control) and UVA-irradiated (test) human epidermis was determined in vitro. Permeability constants, kp, were calculated. Mean ratios of permeability constants for UVA-irradiated and unirradiated epidermis (mean kp test)/(mean kp control) ranged from 2.3 to 3.0 for methanol and from 2.2 to 2.5 for ethanol. These mean ratios were determined using different pieces of epidermis from the same piece of skin for test and control samples. When kp control and kp test were determined on the same piece of epidermis on successive days, the ratios (kp test/kp control) were similar to the mean ratios determined on different pieces of epidermis. For other primary alcohols, propanol, butanol, hexanol, and heptanol, UVA radiation did not alter their permeability constants significantly. Partition coefficients, Km, were determined for ethanol and heptanol using UVA-irradiated and unirradiated stratum corneum. For ethanol, irradiation resulted in a 1.5 to 2.6 times increase in Km. For heptanol, irradiation caused no change in Km. These results demonstrate that the barrier capacity of stratum corneum for small, polar, primary alcohols is diminished (permeability increases) and for higher molecular weight less polar alcohols, is unaffected by small doses of UVA radiation. This increased permeability of small polar alcohols through human skin may be due to enhanced partitioning into UVA-irradiated stratum corneum, which was not apparent for a higher molecular weight less polar alcohol.

  5. 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.

  6. 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

  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. 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.

  9. Outdoor solar UVA dose assessment with EBT2 radiochromic film using spectrophotometer and densitometer measurements.

    PubMed

    Abukassem, I; Bero, M A

    2015-04-01

    Direct measurements of solar ultraviolet radiations (UVRs) have an important role in the protection of humans against UVR hazard. This work presents simple technique based on the application of EBT2 GAFCHROMIC(®) film for direct solar UVA dose assessment. It demonstrates the effects of different parts of the solar spectrum (UVB, visible and infrared) on performed UVA field measurements and presents the measurement uncertainty budget. The gradient of sunlight exposure level permitted the authors to establish the mathematical relationships between the measured solar UVA dose and two measured quantities: the first was the changes in spectral absorbance at the wavelength 633 nm (A633) and the second was the optical density (OD). The established standard relations were also applied to calculate the solar UVA dose variations during the whole day; 15 min of exposure each hour between 8:00 and 17:00 was recorded. Results show that both applied experimental methods, spectrophotometer absorbance and densitometer OD, deliver comparable figures for EBT2 solar UVA dose assessment with relative uncertainty of 11% for spectral absorbance measurements and 15% for OD measurements. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  10. 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

  11. 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.

  12. 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.

  13. 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.

  14. Comparison of UVA-induced ROS and sunscreen nanoparticle-generated ROS in human immune cells.

    PubMed

    Shen, Cenchao; Turney, Terence W; Piva, Terrence J; Feltis, Bryce N; Wright, Paul F A

    2014-05-01

    Oxidative damage to cells and tissues from free radicals induced by ultraviolet (UV) irradiation can be attenuated by sunscreen components, such as ZnO and TiO2 nanoparticles (NPs). Although it is known that reactive oxygen species (ROS) are generated by cells upon exposure to ZnO and TiO2 NPs, it is unknown to what extent the amount generated is altered with UV co-exposure. As it is a critical component for determining the relative risk of these NPs when used in sunscreen formulations, we have investigated ROS generation by these NPs in human THP-1 monocyte immune cells following UVA co-exposure. Whilst the applied UVA dose (6.7 J cm(-2)) did not alter cell viability after 24 h, it induced significant ROS production - causing a 7-fold increase in intracellular peroxide and 3.3-fold increase in mitochondrial superoxide levels after 1 h. However, co-exposure to NPs and UVA generated the same or less ROS than with UVA exposure alone, with the exception of anatase TiO2, which showed significantly increased levels. These findings indicate that ROS generation from nanosunscreens is, in most cases, an insignificant contributor to the overall risk associated with oxidative stress from UVA exposure itself.

  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. Are the surgeons safe during UV-A radiation exposure in collagen cross-linking procedure?

    PubMed

    Shetty, Rashmi; Shetty, Rohit; Mahendradas, Padmamalini; Shetty, Bhujang K

    2012-02-01

    To quantify the effect of scattered UV-A radiation used in the collagen cross-linking (CXL) procedure and the amount of radiation reaching the surgeon and the surrounding area and to estimate the dampening effect by various protective devices. In this case series, 3 patients [aged 25-30 (±2.5) years] with keratoconus underwent a CXL procedure with UV-A light and riboflavin. Irradiance was measured using a spectrometer (Model USB2000; Ocean Optics, Inc) for various distances from the source, at various angles, and for different durations of radiation. The spectrometer was also used to measure the dampening effect produced by gown, latex gloves, and UV-protective glasses. Maximum UV-A radiation (1.4 × 10(-9) mW/cm(2)) was measured at 2 cm from the limbus, when the probe was held at a 45-degree angle to the floor. UV-A radiation reaching the surgeon's eye and the abdomen was 3.403 × 10(-11) and 2.36 × 10(-11) mW/cm(2), respectively. Gown, latex gloves, and UV-protective glasses showed dampening effects of 99.58%, 95.01%, and 99.73%, respectively. CXL appears to be a safe procedure with respect to UV-A radiation exposure to the surgeon. Further safety can be ensured by UV-protective devices.

  17. 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

  18. 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."

  19. Absorption, distribution, and excretion of 8-methoxypsoralen in HRA/Skh mice

    SciTech Connect

    Muni, I.A.; Schneider, F.H.; Olsson, T.A. III; King, M.

    1984-12-01

    The tissue distribution and excretion of (/sup 3/H)8-methoxypsoralen (8-MOP), a well-accepted therapeutic agent for the treatment of psoriasis, was studied in hairless HRA/Skh female mice. Mice were given single oral doses of 6 mg of (/sup 3/H)8-MOP or 5-(/sup 14/C)8-MOP/kg in corn oil. Radiochemical analyses of tissues and excreta were accomplished by liquid scintillation counting. The 8-MOP appeared to be rapidly absorbed through the gastrointestinal tract, where the tritium levels were highest, followed by skin, blood, and liver; levels were lowest in fat (adipose tissue). In female HRA/Skh mice which had not been irradiated with UVA (320-400 nm), 84% of the carbon-14 and 58% of the tritium were recovered in the urine and feces within 24 hours of oral administration of 5-(/sup 14/C)8-MOP or (/sup 3/H)8-MOP, respectively. Animals that were exposed to UVA and received (3H)8-MOP excreted approximately 12% less tritium in the urine and feces compared with the animals which received no UVA.

  20. Structural biology applications of solid state MAS DNP NMR

    NASA Astrophysics Data System (ADS)

    Akbey, Ümit; Oschkinat, Hartmut

    2016-08-01

    Dynamic Nuclear Polarization (DNP) has long been an aim for increasing sensitivity of nuclear magnetic resonance (NMR) spectroscopy, delivering spectra in shorter experiment times or of smaller sample amounts. In recent years, it has been applied in magic angle spinning (MAS) solid-state NMR to a large range of samples, including biological macromolecules and functional materials. New research directions in structural biology can be envisaged by DNP, facilitating investigations on very large complexes or very heterogeneous samples. Here we present a summary of state of the art DNP MAS NMR spectroscopy and its applications to structural biology, discussing the technical challenges and factors affecting DNP performance.

  1. MAS2-8 radar and digital control unit

    NASA Technical Reports Server (NTRS)

    Oberg, J. M.; Ulaby, F. T.

    1974-01-01

    The design of the MAS 2-8 (2 to 8 GHz microwave-active spectrometer), a ground-based sensor system, is presented. A major modification in 1974 to the MAS 2-8, that of a control subsystem to automate the data-taking operation, is the prime focus. The digital control unit automatically changes all system parameters except FM rate and records the return signal on paper tape. The overall system operation and a detailed discussion of the design and operation of the digital control unit are presented.

  2. 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

  3. 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.

  4. 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. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  5. 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.

  6. 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

  7. UVA-Induced DNA Damage and Apoptosis in Red Blood Cells of the African Catfish Clarias gariepinus.

    PubMed

    Sayed, Alaa El-Din Hamid

    2017-08-02

    Ultraviolet-A light (UVA)-induced DNA damage and repair in red blood cells to investigate the sensitivity of African catfish to UVA exposure is reported. Fishes were irradiated with various doses of UVA light (15, 30, and 60 min day(-1) for 3 days). Morphological and nuclear abnormalities in red blood cells were observed in the fish exposed to UVA compared with controls. Morphological alterations such as acanthocytes, crenated cells, swollen cells, teardrop-like cells, hemolyzed cells, and sickle cells were observed. Those alterations were increased after 24 h exposure to UVA light and decreased at 14 days after exposure. The percentage of apoptosis was higher in red blood cells exposed to higher doses of UVA light. No micronuclei were detected, but small nuclear abnormalities such as deformed and eccentric nuclei were observed in some groups. We concluded that exposure to UVA light induced DNA damage, apoptosis, and morphological alterations in red blood cells in catfish; however, catfish were found to be less sensitive to UVA light than wild-type medaka. © 2017 The American Society of Photobiology.

  8. UVA irradiation of the eye modulates the contact hypersensitivity of the skin and intestines by affecting mast cells in mice.

    PubMed

    Yamate, Yurika; Hiramoto, Keiichi; Kasahara, Emiko; Sato, Eisuke F

    2015-05-01

    Ultraviolet A (UVA) irradiation before allergic sensitization induces immunosuppression, but the precise mechanism remained unclear. In this study, we examined the influence of UVA irradiation of the eye on contact hypersensitivity (CHS) and the role of mast cells in CHS. We used two types of haptens, fluorescein isothiocyanate (FITC: a Th2 type hapten) and 4-ethoxymethylene-2-phenyl-2-oxazolin-5-one (oxazolone: a Th1 type hapten). A 300 kJ/m(2) dose of UVA irradiation was delivered to the eyes. After UVA irradiation, we sensitized abdominal shaved skin and challenged the ear epidermis and colons of these mice with each hapten. After UVA irradiation, the CHS of the skin and colon were not inhibited in the FITC-sensitized mice. However, in the oxazolone-sensitized mice, only the CHS of the skin was inhibited by UVA irradiation. The inflammation of the colon became more severe after UVA irradiation. In mast cell-deficient (W/Wv) mice sensitized to FITC, the CHS was weaker than that in WT mice. Moreover, the reduction of immunosuppression in ear swelling was seen for one of the two models they used. These results suggest that the mast cells induced by UVA irradiation of the eye have different roles in the epidermis and colon and have different responses to different haptens. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. 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

  10. Thioredoxin reductase activity may be more important than GSH level in protecting human lens epithelial cells against UVA light.

    PubMed

    Padgaonkar, Vanita A; Leverenz, Victor R; Bhat, Aparna V; Pelliccia, Sara E; Giblin, Frank J

    2015-01-01

    This study compares the abilities of the glutathione (GSH) and thioredoxin (Trx) antioxidant systems in defending cultured human lens epithelial cells (LECs) against UVA light. Levels of GSH were depleted with either L-buthionine-(S,R)-sulfoximine (BSO) or 1-chloro-2,4-dinitrobenzene (CDNB). CDNB treatment also inhibited the activity of thioredoxin reductase (TrxR). Two levels of O2 , 3% and 20%, were employed during a 1 h exposure of the cells to 25 J cm(-2) of UVA radiation (338-400 nm wavelength, peak at 365 nm). Inhibition of TrxR activity by CDNB, combined with exposure to UVA light, produced a substantial loss of LECs and cell damage, with the effects being considerably more severe at 20% O2 compared to 3%. In contrast, depletion of GSH by BSO, combined with exposure to UVA light, produced only a slight cell loss, with no apparent morphological effects. Catalase was highly sensitive to UVA-induced inactivation, but was not essential for protection. Although UVA light presented a challenge for the lens epithelium, it was well tolerated under normal conditions. The results demonstrate an important role for TrxR activity in defending the lens epithelium against UVA light, possibly related to the ability of the Trx system to assist DNA synthesis following UVA-induced cell damage. © 2014 The American Society of Photobiology.

  11. 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.

  12. 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.

  13. Extracellular Polysaccharide Production in a Scytonemin-Deficient Mutant of Nostoc punctiforme Under UVA and Oxidative Stress.

    PubMed

    Soule, Tanya; Shipe, Dexter; Lothamer, Justin

    2016-10-01

    Some cyanobacteria can protect themselves from ultraviolet radiation by producing sunscreen pigments. In particular, the sheath pigment scytonemin protects cells against long-wavelength UVA radiation and is only found in cyanobacteria which are capable of extracellular polysaccharide (EPS) production. The presence of a putative glycosyltransferase encoded within the scytonemin gene cluster, along with the localization of scytonemin and EPS to the extracellular sheath, prompted us to investigate the relationship between scytonemin and EPS production under UVA stress. In this study, it was hypothesized that there would be a relationship between the biosynthesis of scytonemin and EPS under both UVA and oxidative stress, since the latter is a by-product of UVA radiation. EPS production was measured following exposure of wild-type Nostoc punctiforme and the non-scytonemin-producing strain SCY59 to UVA and oxidative stress. Under UVA, SCY59 produced significantly more EPS than the unstressed controls and the wild type, while both strains produced more EPS under oxidative stress compared to the controls. The results suggest that EPS secretion occurs in response to the oxidative stress by-product of UVA rather than as a direct response to UVA radiation.

  14. 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".

  15. Project MAS 1984-1985. OEA Evaluation Report.

    ERIC Educational Resources Information Center

    New York City Board of Education, Brooklyn. Office of Educational Assessment.

    This multi-site instructional program (Project MAS) provides instruction in English as a second language and native language arts, as well as bilingual instruction in mathematics and science to approximately 400 Spanish-speaking schools. It serves third through eighth graders at four sites in the Bronx. Its instructional and non-instructional…

  16. ADP-MAS: A Math and Science Curriculum.

    ERIC Educational Resources Information Center

    National Council of La Raza, Washington, DC.

    This curriculum, Academia del Pueblo-Math and Science (ADP-MAS), is an outgrowth of the National Council of La Raza's Project EXCEL, a supplemental educational enrichment model for at-risk Latino students to be operated by Latino community-based organizations or public institutions, including schools with substantial Latino populations. ADP-MAS…

  17. Size-exclusion chromatographic NMR under HR-MAS.

    PubMed

    Lucena Alcalde, Guillermo; Anderson, Natalie; Day, Iain J

    2017-05-01

    The addition of stationary phases or sample modifiers can be used to modify the separation achievable in the diffusion domain of diffusion NMR experiments or provide information on the nature of the analyte-sample modifier interaction. Unfortunately, the addition of insoluble chromatographic stationary phases can lead to line broadening and degradation in spectral resolution, largely because of differences in magnetic susceptibility between the sample and the stationary phase. High-resolution magic angle spinning (HR-MAS) techniques can be used to remove this broadening. Here, we attempt the application of HR-MAS to size-exclusion chromatographic NMR with limited success. Observed diffusion coefficients for polymer molecular weight reference standards are shown to be larger than those obtained on static samples. Further investigation reveals that under HR-MAS it is possible to obtain reasonably accurate estimates of diffusion coefficients, using either full rotor synchronisation or sophisticated pulse sequences. The requirement for restricting the sample to the centre of the MAS rotor to ensure homogeneous magnetic and RF fields is also tested. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  18. Resolution and polarization distribution in cryogenic DNP/MAS experiments

    PubMed Central

    Barnes, Alexander B.; Corzilius, Björn; Mak-Jurkauskas, Melody L.; Andreas, Loren B.; Bajaj, Vikram S.; Matsuki, Yoh; Belenky, Marina L.; Lugtenburg, Johan; Sirigiri, Jagadishwar R.; Temkin, Richard J.; Herzfeld, Judith; Griffin, Robert G.

    2014-01-01

    This contribution addresses four potential misconceptions associated with high-resolution dynamic nuclear polarization/magic angle spinning (DNP/MAS) experiments. First, spectral resolution is not generally compromised at the cryogenic temperatures at which DNP experiments are performed. As we demonstrate at a modest field of 9 T (380 MHz 1H), 1 ppm linewidths are observed in DNP/MAS spectra of a membrane protein in its native lipid bilayer, and <0.4 ppm linewidths are reported in a crystalline peptide at 85 K. Second, we address the concerns about paramagnetic broadening in DNP/MAS spectra of proteins by demonstrating that the exogenous radical polarizing agents utilized for DNP are distributed in the sample in such a manner as to avoid paramagnetic broadening and thus maintain full spectral resolution. Third, the enhanced polarization is not localized around the polarizing agent, but rather is effectively and uniformly dispersed throughout the sample, even in the case of membrane proteins. Fourth, the distribution of polarization from the electron spins mediated via spin diffusion between 1H–1H strongly dipolar coupled spins is so rapid that shorter magnetization recovery periods between signal averaging transients can be utilized in DNP/MAS experiments than in typical experiments performed at ambient temperature. PMID:20454732

  19. 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.

  20. [Hepatic manifestation of a macrophage activation syndrome (MAS)].

    PubMed

    Nagel, Michael; Schwarting, Andreas; Straub, Beate K; Galle, Peter R; Zimmermann, Tim

    2017-04-04

    Background Elevated liver values are the most common pathological laboratory result in Germany. Frequent findings, especially in younger patients, are nutritive- or medicamentous- toxic reasons, viral or autoimmune hepatitis. A macrophage activation syndrome (MAS) may manifest like a viral infectious disease with fever, hepatosplenomegaly and pancytopenia and is associated with a high mortality. It is based on an enhanced activation of macrophages with increased cytokine release, leading to organ damage and multi-organ failure. In addition to genetic causes, MAS is commonly associated with infections and rheumatic diseases. We report the case of a 26-year-old female patient suffering from MAS as a rare cause of elevated liver enzymes. Methods Patient characteristics, laboratory values, liver histology, bone marrow and radiological imaging were documented and analyzed. Case Report After an ordinary upper airway infection with bronchitis, a rheumatic arthritis appeared and was treated with leflunomide und methotrexate. In the further course of the disease, the patient developed an acute hepatitis with fever, pancytopenia and massive hyperferritinemia. Immunohistochemistry of the liver biopsy revealed hemophagocytosis and activation of CD68-positive macrophages. In the radiological and histological diagnostics of the liver and bone marrow, an MAS was diagnosed as underlying disease of the acute hepatitis. Under therapy with prednisolone, the fever disappeared and transaminases and ferritin rapidly normalized. Conclusion Aside from the frequent causes of elevated liver values in younger patients, such as nutritive toxic, drug induced liver injury, viral or autoimmune hepatitis, especially in case of massive hyperferritinemia, a MAS should be considered as a rare cause of acute liver disease.

  1. Effects of UV-A Radiation on Desmodesmus armatus: Changes in Growth Rate, Pigment Content and Morphological Appearance

    NASA Astrophysics Data System (ADS)

    Pálffy, Károly; Vörös, Lajos

    2006-10-01

    Laboratory cultures of Desmodesmus armatus (R. Chod.) Hegew. were grown under different levels of photosynthetically active radiation (PAR) supplemented with 3.75 mW . cm-2 UV-A radiation. Growth rate was monitored daily, chlorophyl-a concentration, total carotenoid content, cell number and the relative abundance of different coenobial forms was determined at the end of each experiment. Exposure to UV-A radiation resulted in an increasing inhibition of growth towards higher PAR levels, reaching 100% at 400 μmol . m-2 . s-1. Cellular carotenoid content was higher in the presence of UV-A radiation, on the other hand no differences were observed in cellular chlorophyll-a concentration. UV-A radiation also induced changes in coenobium formation with a decreasing proportion of 4-celled coenobia and an increase in the abundance of 2-celled and teratologic coenobia, suggesting that high intensity UV-A radiation may influence cell cycle events or morphology development.

  2. Photobiological implications of melanin photoprotection after UVB-induced tanning of human skin but not UVA-induced tanning.

    PubMed

    Coelho, Sergio G; Yin, Lanlan; Smuda, Christoph; Mahns, Andre; Kolbe, Ludger; Hearing, Vincent J

    2015-03-01

    Repetitive suberythemal UVA and/or UVB exposures were used to generate comparable UV-induced tans in human skin over the course of 2 weeks. To evaluate the potential photoprotective values of those UVA- and/or UVB- induced tans and to avoid the confounding issue of residual UV-induced DNA damage, we waited 1 week before challenging those areas with a 1.5 MED of UVA+UVB after which we measure DNA damage. The results show that the type of UV used to induce skin pigmentation affects the redistribution of melanin in the skin and/or de novo melanin synthesis. The UVA-induced tans failed to even provide a minimal SPF of 1.5, which suggests that producing a tan with UVA-rich sunlamps prior to a holiday or vacation is completely counterproductive. Published 2014. This article is a US Government work and is in the public domain in the USA.

  3. 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.

  4. 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.

  5. Differential sensitivity of T lymphocytes and hematopoietic precursor cells to photochemotherapy with 8-methoxypsoralen and ultraviolet A light.

    PubMed

    Mabed, Mohamed; Coffe, Christian; Racadot, Evelyne; Angonin, Regis; Pavey, Jean-Jaques; Tiberghien, Pierre; Herve, Patrick

    2006-01-01

    The combination of 8-methoxypsoralen (8-MOP) and long wave ultraviolet radiation (UV-A) has immunomodulatory effects and might abolish both graft-vs-host and host-vs-graft reactions after allogeneic hematopoietic stem cell transplantation. In the present study, we have confirmed the sensitivity of T lymphocytes to 8-MOP treatment plus UV-A exposure as evidenced by the abrogation of the alloreactivity in mixed lymphocyte cultures as well as the inhibition of the response to phytohemagglutinin A. However, the clonogenic capacity of the bone marrow hematopoietic progenitors was inhibited with UV-A doses lower than the doses needed to inhibit T-lymphocytes alloreactivity. Moreover, long-term bone marrow cultures showed that 8-MOP plus UV-A treatment had detrimental effects on the more immature bone marrow stem cells. These data were confirmed when murine bone marrow graft was treated with 8-MOP, exposed to UV-A, then transplanted into semiallogeneic recipient mice. The treated cells could not maintain their clonogenic capacity in vivo resulting in death of all animals. Taken together, these data show that ex vivo 8-MOP plus UV-A treatment of the marrow graft cannot be used to prevent post-bone marrow transplantation alloreactivity.

  6. 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

  7. Stabilization of the angiotensin-(1-7) receptor Mas through interaction with PSD95.

    PubMed

    Bian, Weihua; Sun, Licui; Yang, Longyan; Li, Ji-Feng; Hu, Jia; Zheng, Shuai; Guo, Ruihan; Feng, Duiping; Ma, Qian; Shi, Xiaocui; Xiong, Ying; Yang, Xiaomei; Song, Ran; Xu, Jianguo; Wang, Songlin; He, Junqi

    2013-08-01

    The functions and signalling mechanisms of the Ang-(1-7) [angiotensin-(1-7)] receptor Mas have been studied extensively. However, less attention has been paid to the intracellular regulation of Mas protein. In the present study, PSD95 (postsynaptic density 95), a novel binding protein of Mas receptor, was identified, and their association was characterized further. Mas specifically interacts with PDZ1-2, but not the PDZ3, domain of PSD95 via Mas-CT (Mas C-terminus), and the last four amino acids [ETVV (Glu-Thr-Val-Val)] of Mas-CT were determined to be essential for this interaction, as shown by GST pull-down, co-immunoprecipitation and confocal co-localization experiments. Gain-of-function and loss-of-function studies indicated that PSD95 enhanced Mas protein expression by increasing the stabilization of the receptor. Mas degradation was robustly inhibited by the proteasome inhibitor MG132 in time- and dose-dependent manners, and the expression of PSD95 impaired Mas ubiquitination, indicating that the PSD95-Mas association inhibits Mas receptor degradation via the ubiquitin-proteasome proteolytic pathway. These findings reveal a novel mechanism of Mas receptor regulation by which its expression is modulated at the post-translational level by ubiquitination, and clarify the role of PSD95, which binds directly to Mas, blocking the ubiquitination and subsequent degradation of the receptor via the ubiquitin-proteasome proteolytic pathway.

  8. Activation of p38 MAP Kinase and JNK Pathways by UVA Irradiation

    PubMed Central

    Zhang, Jack; Bowden, G. Tim

    2014-01-01

    There are more than two million new cases of non-melanoma skin cancers (NMSCs) diagnosed each year in the United States. The clear etiological factor is chronic exposure to solar radiation from the sun. The wavelengths of solar light that reach the earth’s surface include UVB (280-320nm) which accounts for 1-10% and UVA (320-400nm) which accounts for 90-99% of the radiation. While most of the published research has focused on the effects of UVB, little is known concerning UVA-mediated signal transduction pathways and their role in skin tumor promotion and progression giving rise to squamous cell carcinomas (SCCs). Here we have focused on UVA-mediated activation of p38 MAP kinase and c-Jun N-terminal kinase (JNK) and their roles in activator protein-1 (AP-1) mediated transcription, cyclooxygenase-2 (COX-2) and Bcl-XL expression. Since p38 MAP kinase and JNK play major roles in the expression of UVA-induced AP-1, COX-2 and Bcl-XL, pharmacological inhibitors of these kinases may be useful in the chemoprevention of SCC skin cancer. PMID:21858326

  9. Epidemiological evidence that UVA radiation is involved in the genesis of cutaneous melanoma.

    PubMed

    Autier, Philippe; Doré, Jean-François; Eggermont, Alexander M M; Coebergh, Jan W

    2011-03-01

    Epidemiological data have contributed to the classification in 2009 of the full ultraviolet (UV) radiation spectrum as carcinogenic to humans. We reviewed the epidemiological evidence that UVA could be involved in the genesis of cutaneous melanoma. Use of artificial UV tanning devices (sunbeds) consists mainly of repeated exposure to high UVA doses. Epidemiological studies published over the last years confirmed the association between sunbed use and melanoma. Sunbed use is the most probable cause of an epidemic of melanoma that took place in Iceland from 1990 to 2006. The four-fold increase in melanoma incidence was not followed by an increase in melanoma mortality. Sunscreens were primarily devised for the prevention of sunburn, and UVB is the wavelength causing most sunburns. All observational studies and randomized trials show that sunscreen use may extend sun exposure intended for getting a tan, while it does not necessarily decrease sunburn occurrence. Sunscreen use for tan acquisition would thus lead to similar exposure to UVB and greater exposure to UVA, which could explain the slightly higher melanoma risk often found among sunscreen users. UVA could be involved in the occurrence of nonlife-threatening melanoma. The increasing use of sunbeds and of sunscreens may partly explain why melanoma incidence increases in most light-skinned populations without concomitant increase in mortality.

  10. Effects of UV-A radiation on lens epithelial NaK-ATPase in organ culture.

    PubMed

    Dovrat, A; Weinreb, O

    1999-06-01

    To investigate the mechanisms involved in the damage caused by UV-A irradiation at 365 nm on the eye lens. Bovine lenses obtained from animals 1 to 5 years of age were placed in specially designed organ culture chambers for preincubation. Twenty-four hours later, the lenses were irradiated by 33 J/cm2 UV-A at 365 nm. During irradiation, the lenses were oriented in the culture so that the anterior surface faced the incident UV-A radiation source. After irradiation, lens optical quality was monitored throughout the 8 days of the culture period, and lens samples were taken for analysis of NaK-ATPase activity. Lens optics and NaK-ATPase activity were affected by irradiation of 33 J/cm2. The effects on lens epithelial NaK-ATPase activity were stronger at the equators than at the center. The damage to the activity at the center was reversible, as the lens optically recovered from the LW-A damage. Lens NaK-ATPase activity can recover from damage caused by UV-A at 365 nm. When the lenses received irradiation of 33 J/cm2, NaK-ATPase activity recovered from the damage during the culture period only at the center and not at the equators of the epithelium.

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Smartphone-Based Android app for Determining UVA Aerosol Optical Depth and Direct Solar Irradiances.

    PubMed

    Igoe, Damien P; Parisi, Alfio; Carter, Brad

    2014-01-01

    This research describes the development and evaluation of the accuracy and precision of an Android app specifically designed, written and installed on a smartphone for detecting and quantifying incident solar UVA radiation and subsequently, aerosol optical depth at 340 and 380 nm. Earlier studies demonstrated that a smartphone image sensor can detect UVA radiation and the responsivity can be calibrated to measured direct solar irradiance. This current research provides the data collection, calibration, processing, calculations and display all on a smartphone. A very strong coefficient of determination of 0.98 was achieved when the digital response was recalibrated and compared to the Microtops sun photometer direct UVA irradiance observations. The mean percentage discrepancy for derived direct solar irradiance was only 4% and 6% for observations at 380 and 340 nm, respectively, lessening with decreasing solar zenith angle. An 8% mean percent difference discrepancy was observed when comparing aerosol optical depth, also decreasing as solar zenith angle decreases. The results indicate that a specifically designed Android app linking and using a smartphone image sensor, calendar and clock, with additional external narrow bandpass and neutral density filters can be used as a field sensor to evaluate both direct solar UVA irradiance and low aerosol optical depths for areas with low aerosol loads. © 2013 The American Society of Photobiology.

  18. Strawberry-Based Cosmetic Formulations Protect Human Dermal Fibroblasts against UVA-Induced Damage.

    PubMed

    Gasparrini, Massimiliano; Forbes-Hernandez, Tamara Y; Afrin, Sadia; Reboredo-Rodriguez, Patricia; Cianciosi, Danila; Mezzetti, Bruno; Quiles, Josè L; Bompadre, Stefano; Battino, Maurizio; Giampieri, Francesca

    2017-06-14

    Extreme exposure of skin to Ultraviolet A (UVA)-radiation may induce a dysregulated production of reactive oxygen species (ROS) which can interact with cellular biomolecules leading to oxidative stress, inflammation, DNA damage, and alteration of cellular molecular pathways, responsible for skin photoaging, hyperplasia, erythema, and cancer. For these reasons, the use of dietary natural bioactive compounds with remarkable antioxidant activity could be a strategic tool to counteract these UVA-radiation-caused deleterious effects. Thus, the purpose of the present work was to test the efficacy of strawberry (50 μg/mL)-based formulations supplemented with Coenzyme Q10 (100 μg/mL) and sun protection factor 10 in human dermal fibroblasts irradiated with UVA-radiation. The apoptosis rate, the amount of intracellular reactive oxygen species (ROS) production, the expression of proteins involved in antioxidant and inflammatory response, and mitochondrial functionality were evaluated. The results showed that the synergic topical use of strawberry and Coenzyme Q10 provided a significant (p < 0.05) photoprotective effect, reducing cell death and ROS, increasing antioxidant defense, lowering inflammatory markers, and improving mitochondrial functionality. The obtained results suggest the use of strawberry-based formulations as an innovative, natural, and useful tool for the prevention of UVA exposure-induced skin diseases in order to decrease or substitute the amount of synthetic sunscreen agents.

  19. Strawberry-Based Cosmetic Formulations Protect Human Dermal Fibroblasts against UVA-Induced Damage

    PubMed Central

    Gasparrini, Massimiliano; Forbes-Hernandez, Tamara Y.; Afrin, Sadia; Reboredo-Rodriguez, Patricia; Cianciosi, Danila; Mezzetti, Bruno; Quiles, Josè L.; Bompadre, Stefano; Battino, Maurizio; Giampieri, Francesca

    2017-01-01

    Extreme exposure of skin to Ultraviolet A (UVA)-radiation may induce a dysregulated production of reactive oxygen species (ROS) which can interact with cellular biomolecules leading to oxidative stress, inflammation, DNA damage, and alteration of cellular molecular pathways, responsible for skin photoaging, hyperplasia, erythema, and cancer. For these reasons, the use of dietary natural bioactive compounds with remarkable antioxidant activity could be a strategic tool to counteract these UVA-radiation-caused deleterious effects. Thus, the purpose of the present work was to test the efficacy of strawberry (50 μg/mL)-based formulations supplemented with Coenzyme Q10 (100 μg/mL) and sun protection factor 10 in human dermal fibroblasts irradiated with UVA-radiation. The apoptosis rate, the amount of intracellular reactive oxygen species (ROS) production, the expression of proteins involved in antioxidant and inflammatory response, and mitochondrial functionality were evaluated. The results showed that the synergic topical use of strawberry and Coenzyme Q10 provided a significant (p < 0.05) photoprotective effect, reducing cell death and ROS, increasing antioxidant defense, lowering inflammatory markers, and improving mitochondrial functionality. The obtained results suggest the use of strawberry-based formulations as an innovative, natural, and useful tool for the prevention of UVA exposure-induced skin diseases in order to decrease or substitute the amount of synthetic sunscreen agents. PMID:28613256

  20. 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.

  1. Structural biology applications of solid state MAS DNP NMR.

    PubMed

    Akbey, Ümit; Oschkinat, Hartmut

    2016-08-01

    Dynamic Nuclear Polarization (DNP) has long been an aim for increasing sensitivity of nuclear magnetic resonance (NMR) spectroscopy, delivering spectra in shorter experiment times or of smaller sample amounts. In recent years, it has been applied in magic angle spinning (MAS) solid-state NMR to a large range of samples, including biological macromolecules and functional materials. New research directions in structural biology can be envisaged by DNP, facilitating investigations on very large complexes or very heterogeneous samples. Here we present a summary of state of the art DNP MAS NMR spectroscopy and its applications to structural biology, discussing the technical challenges and factors affecting DNP performance. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Commercial facility site selection simulating based on MAS

    NASA Astrophysics Data System (ADS)

    Chao, Yi; Li, Qingquan; Zheng, Guizhou

    2008-10-01

    The location of commercial facility decides the benefit of the operator to a large degree. Existing location methods can express the static relationships between site selection result and location factors, but there still are some limites when express the dynamic and uncertain relationship between them. Hence, a dynamic, stochastic and forecastable location model should be built which can introduce the customer's behavior into the model and combine the macro pattern and micro spatial interaction. So the authors proposes Geosim-LM based on MAS. Geosim-LM has 3 kinds of agents, CustAgent, SiteAgent and GovAgent. They represent the customers, commercial fercilities and government. The land type, land price and traffic are the model environment. Then Geosim-LM is applied in the bank branches site evaluation and selection in Liwan district, Guangzhou. In existing bank branches site evaluation, there are 70% consistent in score grade between result of Geosim-LM after 200 round runing and actual rebust location. It proves the model is reliable and feasible. The conclusions can be get from the paper. MAS have advantages in location choice than existed methods. The result of Geosim-LM running can powerfully proves that building location model based on MAS is feasible.

  3. Solvent signal suppression for high-resolution MAS-DNP

    NASA Astrophysics Data System (ADS)

    Lee, Daniel; Chaudhari, Sachin R.; De Paëpe, Gaël

    2017-05-01

    Dynamic nuclear polarization (DNP) has become a powerful tool to substantially increase the sensitivity of high-field magic angle spinning (MAS) solid-state NMR experiments. The addition of dissolved hyperpolarizing agents usually results in the presence of solvent signals that can overlap and obscure those of interest from the analyte. Here, two methods are proposed to suppress DNP solvent signals: a Forced Echo Dephasing experiment (FEDex) and TRAnsfer of Populations in DOuble Resonance Echo Dephasing (TRAPDORED) NMR. These methods reintroduce a heteronuclear dipolar interaction that is specific to the solvent, thereby forcing a dephasing of recoupled solvent spins and leaving acquired NMR spectra free of associated resonance overlap with the analyte. The potency of these methods is demonstrated on sample types common to MAS-DNP experiments, namely a frozen solution (of L-proline) and a powdered solid (progesterone), both containing deuterated glycerol as a DNP solvent. The proposed methods are efficient, simple to implement, compatible with other NMR experiments, and extendable past spectral editing for just DNP solvents. The sensitivity gains from MAS-DNP in conjunction with FEDex or TRAPDORED then permits rapid and uninterrupted sample analysis.

  4. 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

  5. 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

  6. 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.

  7. 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.

  8. 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.

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

    PubMed

    Kim, Han Bit; Yoo, Byung Sun

    2016-10-01

    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.

  10. 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.

  11. 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

  12. 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

  13. 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

    2017-07-01

    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. Copyright © 2017 Elsevier Inc. All rights reserved.

  14. 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  15. 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.

  16. Activation of transcription factor AP-2 mediates UVA radiation- and singlet oxygen-induced expression of the human intercellular adhesion molecule 1 gene

    SciTech Connect

    Grether-Beck, S.; Olaizola-Horn, S.; Schmitt, H.; Grewe, M.

    1996-12-10

    UVA radiation is the major component of the UV solar spectrum that reaches the earth, and the therapeutic application of UVA radiation is increasing in medicine. Analysis of the cellular effects of UVA radiation has revealed that exposure of human cells to UVA radiation at physiological doses leads to increased gene expression and that this UVA response is primarily mediated through the generation of singlet oxygen. In this study, the mechanisms by which UVA radiation induces transcriptional activation of the human intercellular adhesion molecule 1 (ICAM-1) were examined. UVA radiation was capable of inducing activation of the human ICAM-1 promoter and increasing OCAM-1 mRNA and protein expression. These UVA radiation effects were inhibited by singlet oxygen quenchers, augmented by enhancement of singlet oxygen life-time, and mimicked in unirradiated cells by a singlet oxygen-generating system. UVA radiation as well as singlet oxygen-induced ICAM-1 promoter activation required activation of the transcription factor AP-2. Accordingly, both stimuli activated AP-2, and deletion of the putative AP-2-binding site abrogated ICAM-1 promoter activation in this system. This study identified the AP-2 site as the UVA radiation- and singlet oxygen-responsive element of the human ICAM-1 gene. The capacity of UVA radiation and/or singlet oxygen to induce human gene expression through activation of AP-2 indicates a previously unrecognized role of this transcription factor in the mammalian stress response. 38 refs., 3 figs., 3 tabs.

  17. The MicroMAS CubeSat Mission

    NASA Astrophysics Data System (ADS)

    Cahoy, K.; Blackwell, W. J.; Allen, G.; Bury, M.; Efromson, R.; Galbraith, C.; Hancock, T.; Leslie, V.; Osaretin, I.; Retherford, L.; Scarito, M.; Shields, M.; Toher, D.; Wight, K.; Miller, D.; Marinan, A.; Paek, S.; Peters, E.; Schmidt, F. H.; Alvisio, B.; Wise, E.; Masterson, R.; Franzim Miranda, D.; Crail, C.; Kingsbury, R.; Souffrant, A.; Orrego, L.; Eslinger, G.; Nicholas, A.; Pong, C.

    2012-12-01

    The recently published Midterm Assessment of NASA's Implementation of the Decadal Survey finds that, "The nation's Earth observing system is beginning a rapid decline in capability as long-running missions end and key new missions are delayed, lost, or canceled. The projected loss of observing capability could have significant adverse consequences for science and society." In this presentation, we explore low-cost, mission-flexible, and rapidly deployable spaceborne sensors that can meet stringent performance requirements pervading the NASA Earth Science measurement programs, including especially the recommended NRC Decadal Survey missions. New technologies have enabled a novel approach toward this science observational goal, and in this paper we describe recent technology develop efforts to address the challenges above through the use of CubeSat radiometers. The Micro-sized Microwave Atmospheric Satellite (MicroMAS) is a 3U cubesat (30x10x10 cm, ~4kg) hosting a passive microwave spectrometer operating near the 118.75-GHz oxygen absorption line. The focus of the first MicroMAS mission (hereafter, MicroMAS-1) is to observe convective thunderstorms, tropical cyclones, and hurricanes from a near-equatorial orbit at approximately 500-km altitude. A MicroMAS flight unit is currently being developed in anticipation of a 2014 launch to be provided by NASA. A parabolic reflector is mechanically rotated as the spacecraft orbits the earth, thus directing a cross-track scanned beam with FWHM beamwidth of 2.4-degrees, yielding an approximately 25-km diameter footprint from a nominal altitude of 500 km. Radiometric calibration is carried out using observations of cold space, the earth's limb, and an internal noise diode that is weakly coupled through the RF front-end electronics. A key technology feature is the development of an ultra-compact intermediate frequency processor module for channelization, detection, and A-to-D conversion. The antenna system and RF front

  18. The Possible Pre- and Post-UVA Radiation Protective Effect of Amaranth Oil on Human Skin Fibroblast Cells

    PubMed Central

    Wolosik, Katarzyna; Zareba, Ilona; Surazynski, Arkadiusz; Markowska, Agnieszka

    2017-01-01

    Background: The health effects of Amaranth Oil (AO) are attributed to its specific chemical composition. That makes it an outstanding natural product for the prevention and treatment of ultraviolet (UV) irradiation-related pathologies such as sunburn, photoaging, photoimmunosuppression, and photocarcinogenesis. Most of the studies are taken on animal model, and there is a lack of research on the endogenous effect of AO on fibroblast level, where UVA takes it harmful place. Objective: The aim of this study was evaluation if AO can protect or abolish UVA exposure effect on human skin fibroblast. Materials and Methods: The 0.1% AO, 0.25% AO, and 0.5% AO concentration and irradiation for 15 min under UVA-emitting lamp were studied in various condition. In all experiments, the mean values for six assays ± standard deviations were calculated. Results: Pretreatment with various concentrations of AO was tested. The highest concentration of AO where cell survival was observed was 0.5%. Cytotoxicity assays provided evidence for pre- and post-UVA protective effect of 0.1% AO among three tested concentrations. The results also provide evidence that UVA has inhibitory effect on collagen biosynthesis in confluent skin fibroblast, but presence of 0.1% AO abolishes pre- and post-UVA effect comparing to other used AO concentration. The assessment results on DNA biosynthesis show the significant abolished post-UVA effect when 0.1% and 0.5% of AO were added. Conclusion: AO gives pre- and post-UVA protection in low concentration. This provides the evidence for using it not as a main protective factor against UV but as one of the combined components in cosmetic formulation. SUMMARY The recommended Amaranth Oil (AO) concentration in cosmetic formulation is between 0.1 and 5%Pretreatment with various concentrations of AO suggests to use the highest 0.5% concentration of AO in human skin fibroblast culturesThe 0.1% of AO in fibroblast cultures, protects and abolishes effect of

  19. Rapid acquisition of wideline MAS solid-state NMR spectra with fast MAS, proton detection, and dipolar HMQC pulse sequences.

    PubMed

    Rossini, Aaron J; Hanrahan, Michael P; Thuo, Martin

    2016-09-14

    The solid-state NMR spectra of many NMR active elements are often extremely broad due to the presence of chemical shift anisotropy (CSA) and/or the quadrupolar interaction (for nuclei with spin I > 1/2). These NMR interactions often give rise to wideline solid-state NMR spectra which can span hundreds of kHz or several MHz. Here we demonstrate that by using fast MAS, proton detection and dipolar hetero-nuclear multiple-quantum (D-HMQC) pulse sequences, it is possible to rapidly acquire 2D spectra which correlate (1)H chemical shifts to the indirectly detected wideline MAS powder patterns of dipolar coupled hetero-nuclei. The D-HMQC pulse sequence enables broadband excitation of the wideline hetero-nuclear NMR spectrum and provides higher sensitivity by detecting the narrower and more sensitive (1)H NMR signal. This approach is demonstrated for the rapid acquisition of 2D (1)H detected (195)Pt solid-state NMR spectra of cisplatin and transplatin and the (71)Ga solid-state NMR spectrum of a self-assembled Ga coordination polymer of unconfirmed structure. This approach should be broadly applicable for the rapid acquisition of wideline MAS solid-state NMR spectra of moderately abundant NMR nuclei.

  20. 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.

  1. Coexistence effect of UVA absorbers to increase their solubility and stability of supersaturation.

    PubMed

    Endo, M; Mukawa, T; Sato, N; Maezawa, D; Ohtsu, Y; Kuroda, A; Wakabayashi, M; Asakura, K

    2014-12-01

    Sunscreens containing UVA absorbers in high concentrations are expected to be developed, since recent studies have suggested the possibility of involvement of UVA ray in skin cancer and early skin aging. Solubility and stability of supersaturation of UVA absorbers in UVB absorber were determined in the absence and the presence of cosmetic oil. Coexistence effect of UVA absorbers was analyzed to dissolve them in high concentrations. Two UVA absorbers, diethylamino hydroxybenzoyl hexyl benzoate (DHHB) and butyl methoxydibenzoylmethane (BMDM), a UVB absorber, 2-ethylhexyl methoxycinnamate (EHMC), and a cosmetic oil, 2-ethylhexyl ester of oligomer of hydroxystearic acid (EH-O-HSA), were used. Their solutions were prepared at 80°C and cooled to 5°C. The solid DHHB and/or BMDM were added to it, and the time evolution of concentrations of the UVA absorbers in the solution phase was monitored. At the saturation in the absence of EH-O-HSA at 5°C, weight ratio of DHHB and BMDM to EHMC was 0.39/1.00 and 0.22/1.00, respectively. Addition of EH-O-HSA slightly changed the solubility of DHHB and BMDM. When the weight ratio of EH-O-HSA to EHMC was 0.20/1.00, weight ratio of DHHB and BMDM to EHMC was 0.35/1.00 and 0.25/1.00, respectively at the saturation at 5°C. In the presence of EH-O-HSA, a strong coexistence effect of DHHB and BMDM was found on their solubility. A thermodynamically stable saturated solution at 5°C having the composition that DHHB: BMDM: EHMC: EH-O-HSA = 0.47: 0.46: 1.00: 0.20 was obtained by the simultaneous addition of solid DHHB and BMDM into the initial solution. The solution type composite having the highest concentrations of DHHB and BMDM prepared in this study exhibited critical wavelength at 368 nm that was just below the border for sunscreens being qualified as 'Broad Spectrum' protection under the new rule launched by US FDA. © 2014 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

  2. Protective effects of phenolic fraction of blue honeysuckle fruits against UVA-induced damage to human keratinocytes.

    PubMed

    Svobodová, Alena; Rambousková, Jana; Walterová, Daniela; Vostálová, Jitka

    2008-06-01

    In this study, the UVA (photo)protective activity of the phenolic fraction of L. caerulea fruits (PFLC) was assessed in human keratinocytes HaCaT. The keratinocytes were pre- or post-treated with PFLC (1-250 mg/l) and exposed to UVA irradiation (10-30 J/cm(2)). The results showed that both pre- and post-treatment with PFLC significantly suppressed UVA-induced ROS production, which was also revealed as a decrease in intracellular lipid peroxidation and elevation of reduced glutathione. Protection was concentration-dependent with a maximum at 50 mg/l. These results suggest that PFLC attenuates UVA-induced oxidative stress by reduction of ROS generation and ROS-mediated damage. For this reason, PFLC has potentially skin-protective functions against the deleterious effects of sunlight.

  3. 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

  4. 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.

  5. 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

  6. beta-carotene production enhancement by UV-A radiation in Dunaliella bardawil cultivated in laboratory reactors.

    PubMed

    Mogedas, Benito; Casal, Carlos; Forján, Eduardo; Vílchez, Carlos

    2009-07-01

    beta-carotene is an antioxidant molecule of commercial value that can be naturally produced by certain microalgae that mostly belong to the genus Dunaliella. So far, nitrogen starvation has been the most efficient condition for enhancing beta-carotene accumulation in Dunaliella. However, while nitrogen starvation promotes beta-carotene accumulation, the cells become non-viable; consequently under such conditions, continuous beta-carotene production is limited to less than 1 week. In this study, the use of UV-A radiation as a tool to enhance long-term beta-carotene production in Dunaliella bardawil cultures was investigated. The effect of UV-A radiation (320-400 nm) added to photosynthetically active radiation (PAR, 400-700 nm) on growth and carotenoid accumulation of D. bardawil in a laboratory air-fluidized bed photobioreactor was studied. The results were compared with those from D. bardawil control cultures incubated with PAR only. The addition of 8.7 W.m(-2) UV-A radiation to 250 Wm(-2) PAR stimulated long-term growth of D. bardawil. Throughout the exponential growth period the UV-A irradiated cultures showed enhanced carotenoid accumulation, mostly as beta-carotene. After 24 days, the concentration of beta-carotene in UV-A irradiated cultures was approximately two times that of control cultures. Analysis revealed that UV-A clearly induced major accumulation of all-trans beta-carotene. In N-starved culture media, beta-carotene biosynthesis in UV-A irradiated cultures was stimulated. We conclude that the addition of UV-A to PAR enhances carotenoid production processes, specifically all-trans beta-carotene, in D. bardawil cells without negative effects on cell growth.

  7. 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.

  8. Ultraviolet (UVB and UVA) photoprotector activity and percutaneous penetration of extracts obtained from Arrabidaea chica.

    PubMed

    Siraichi, Jackeline T G; Pedrochi, Franciana; Natali, Maria R M; Ueda-Nakamura, Tânia; Filho, Benedito P Dias; Bento, Antonio C; Baesso, Mauro L; Nakamura, Celso V

    2013-10-01

    The aim of this work is to investigate the photoprotection activity and toxicity level of formulations containing the extract and its fractions obtained from leaves of Arrabidaea chica. The ex vivo percutaneous penetration of the extract was evaluated using the photoacoustic spectroscopy technique. The formulation presented optical absorption in the ultraviolet region, including UVA and UVB. This formulation was obtained without adding inorganic UV filters, as is frequently used in commercial sunscreens. The results showed a penetration rate similar to those of commercial sunscreens with its presence on the skin surface at least 180 min after the application. This formulation presented no toxic effects evaluated using hematological, biochemical, and histological assays. The results suggest that the formulation from the leaves of A. chica provides substantial protection against UVA + UVB radiation with a possible advantage of being natural and free of inorganic compounds compared with the majority of available commercial sunscreens.

  9. Cyanobacterial phytochrome Cph2 is a negative regulator in phototaxis toward UV-A.

    PubMed

    Moon, Yoon-Jung; Kim, Soo Youn; Jung, Kwang-Hwan; Choi, Jong-Soon; Park, Young Mok; Chung, Young-Ho

    2011-01-21

    We investigated the wavelength dependence and photon-fluence rate response relationship for phototaxis of wild-type and a cyanobacterial phytochrome 2 (cph2) mutant in cyanobacterium Synechocystis sp. PCC 6803. Compared to wild-type, the cph2 mutant exhibited maximal activity for positive phototaxis at the near-UV spectral range. Two cysteine to serine substitutions in two chromophore-binding domains showed a similar cph2 mutant phenotype under UV-A. Epistasis of a pixJ mutation over a cph2 mutation implied that pixJ gene acts downstream of the cph2 gene with respect to UV-A-induced positive phototaxis. Therefore, we suggest that Cph2 is essential for the inhibition of positive phototaxis toward UV-A. Copyright © 2010 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  10. Photoirradiation of polycyclic aromatic hydrocarbon diones by UVA light leading to lipid peroxidation.

    PubMed

    Zhao, Yuewei; Xia, Qingsu; Yin, Jun-Jie; Yu, Hongtao; Fu, Peter P

    2011-09-01

    Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous genotoxic environmental pollutants and potentially pose a health risk to humans. In most if not all cases, PAHs in the environment can be oxidized into their corresponding PAH-diones. This process is considered a detoxification pathway with regard to tumorigenicity. Nevertheless, photo-induced toxicological activity of PAH-diones has not been systematically investigated. In this study, we show that 27 potential environmental PAH-diones induced lipid peroxidation, in a dose (light) response manner, when irradiated with UVA at 7 and 21 J cm(-2). Photoirradiation in the presence of sodium azide, deuterated methanol, or superoxide dismutase revealed that lipid peroxidation is mediated by reactive oxygen species. Electron spin resonance (ESR) spin trapping studies supported this observation. These results suggest that UVA photoirradiation of PAH-diones generates reactive oxygen species and induces lipid peroxidation. Published by Elsevier Ltd.

  11. 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.

  12. The global response of Nostoc punctiforme ATCC 29133 to UVA stress, assessed in a temporal DNA microarray study.

    PubMed

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

    2013-01-01

    Cyanobacteria in nature are exposed not only to the visible spectrum of sunlight but also to its harmful ultraviolet components (UVA and UVB). We used Nostoc punctiforme ATCC 29133 as a model to study the UVA response by analyzing global gene expression patterns using genomic microarrays. UVA exposure resulted in the statistically detectable differential expression of 573 genes of the 6903 that were probed, compared with that of the control cultures. Of those genes, 473 were up-regulated, while only 100 were down-regulated. Many of the down-regulated genes were involved in photosynthetic pigment biosynthesis, indicating a significant shift in this metabolism. As expected, we detected the up-regulation of genes encoding antioxidant enzymes and the sunscreen, scytonemin. However, a majority of the up-regulated genes, 47%, were unassignable bioinformatically to known functional categories, suggesting that the UVA stress response is not well understood. Interestingly, the most dramatic up-regulation involved several contiguous genes of unassigned metabolism on plasmid A. This is the first global UVA stress response analysis of any phototrophic microorganism and the differential expression of 8% of the genes of the Nostoc genome indicates that adaptation to UVA in Nostoc has been an evolutionary force of significance. © 2012 Wiley Periodicals, Inc. Photochemistry and Photobiology © 2012 The American Society of Photobiology.

  13. The deceptive nature of UVA-tanning versus the modest protective effects of UVB-tanning on human skin

    PubMed Central

    Miyamura, Yoshinori; Coelho, Sergio G.; Schlenz, Kathrin; Batzer, Jan; Smuda, Christoph; Choi, Wonseon; Brenner, Michaela; Passeron, Thierry; Zhang, Guofeng; Kolbe, Ludger; Wolber, Rainer; Hearing, Vincent J.

    2010-01-01

    Summary The relationship between human skin pigmentation and protection from ultraviolet (UV) radiation is an important element underlying differences in skin carcinogenesis rates. The association between UV damage and the risk of skin cancer is clear, yet a strategic balance in exposure to UV needs to be met. Dark skin is protected from UV-induced DNA damage significantly more than light skin due to the constitutively higher pigmentation but an as yet unresolved and important question is what photoprotective benefit, if any, is afforded by facultative pigmentation (i.e. a tan induced by UV exposure). To address that and to compare the effects of various wavelengths of UV, we repetitively exposed human skin to suberythemal doses of UVA and/or UVB over 2 weeks after which a challenge dose of UVA&UVB was given. Although visual skin pigmentation (tanning) elicited by the different UV exposure protocols was similar, the melanin content and UV-protective effects against DNA damage in UVB-tanned skin (but not in UVA-tanned skin) were significantly higher. UVA-induced tans seem to result from the photooxidation of existing melanin and its precursors with some redistribution of pigment granules while UVB stimulates melanocytes to up-regulate melanin synthesis and increases pigmentation coverage, effects that are synergistically stimulated in UVA and UVB-exposed skin. Thus, UVA-tanning contributes essentially no photoprotection, although all types of UV-induced tanning result in DNA and cellular damage which can eventually lead to photocarcinogenesis. PMID:20979596

  14. Milli-Arcsecond (MAS) Imaging of the Solar Corona

    NASA Astrophysics Data System (ADS)

    Davila, Joseph M.; Oktem, Figen S.; Kamalabadi, Farzad; O'Neill, John; Novo-Gradac, Anne-Marie; Daw, Adrian N.; Rabin, Douglas M.

    2016-05-01

    Dissipation in the solar corona is believed to occur in extremely thin current sheets of order 1-100 km. Emission from these hot but thin current sheets should be visible in coronal EUV emission lines. However, this spatial scale is far below the resolution of existing imaging instruments, so these dissipation sites have never been observed individually. Conventional optics cannot be manufactured with sufficient surface figure accuracy to obtain the required spatial resolution in the extreme-ultraviolet where these hot plasmas radiate. A photon sieve, a diffractive imaging element similar to a Fresnel zone plate, can be manufactured to provide a few milli-arcsec (MAS) resolution, with much more readily achievable tolerances than with conventional imaging technology. Prototype photon sieve elements have been fabricated and tested in the laboratory. A full-scale ultra-high resolution instrument will require formation flying and computational image deconvolution. Significant progress has been made in overcoming these challenges, and some recent results in these areas are discussed. A simple design for a sounding rocket concept demonstration payload is presented that obtains 80 MAS (0.080 arcsec) imaging with a 100 mm diameter photon sieve to image Fe XIV 334 and Fe XVI 335. These images will show the structure of the corona at a resolution never before obtained, and they will also allow a study of the temperature structure in the dissipation region.

  15. UV-A and UV-C light induced hydrophilization of dental implants.

    PubMed

    Al Qahtani, Mohammed S A; Wu, Yanyun; Spintzyk, Sebastian; Krieg, Peter; Killinger, Andreas; Schweizer, Ernst; Stephan, Ingrid; Scheideler, Lutz; Geis-Gerstorfer, Jürgen; Rupp, Frank

    2015-08-01

    Wettability is increasingly considered to be an important factor determining biological responses to implant materials. In this context, the purpose of this study was to compare the dynamic wettability of dental implants made from different bulk materials and modified by different surface modifications, and to analyze the respective changes of wettability upon irradiating these implants by UV-A or UV-C light. Four original screw-type implants were investigated: One grit-blasted/acid-etched and one anodically oxidized titanium, one zirconia and one polyetheretherketone implant. Additionally, experimental, screwless, machined titanium cylinders were included in the study. Part of that cylinders and of blasted/etched implants were further modified by a magnetron-sputtered photocatalytic anatase thin film. Scanning electron microscopy was used to investigate the surface micro- and nanostructures. Samples were treated by UV-A (382nm, 25mWcm(-2)) and UV-C (260nm, 15mWcm(-2)) for entire 40min, respectively, and their wettability was quantified by dynamic contact angle (CA) analysis from multi-loop Wilhelmy experiments. All implants are characterized by submicron- and nanosized surface features. Unexposed implants were hydrophobic (CA>90°). Upon UV-A, solely the implants with anatase coating became superhydrophilic (CA<5°). Upon UV-C, the blasted/etched implants turned superhydrophilic, the anodized titanium and the zirconia implants were considerably (CA=34° and 27°, respectively) and the PEEK implants slightly (CA=79°) hydrophilized. The wettability of implant surfaces can be improved by UV irradiation. The efficiency of UV-A and UV-C irradiation to lower the CA by photocatalysis or photolysis, however, is strongly dependent on the specific material and surface. Thus, attempts to photofunctionalize these surfaces by irradiation is expected to result in a different pattern of bioresponses. Copyright © 2015 Academy of Dental Materials. Published by Elsevier Ltd. All

  16. Assessing the effects of UVA photocatalysis on soot-coated TiO2-containing mortars.

    PubMed

    De la Rosa, José M; Miller, Ana Z; Pozo-Antonio, J Santiago; González-Pérez, José A; Jiménez-Morillo, Nicasio T; Dionisio, Amelia

    2017-12-15

    The deposition of soot on building surfaces darkens their colour and leads to undesirable black crusts, which are one of the most serious problems on the conservation of built cultural heritage. As a preventive strategy, self-cleaning systems based on the use of titanium dioxide (TiO2) coatings have been employed on building materials for degrading organic compounds deposited on building surfaces, improving their durability and performance. In this study, the self-cleaning effect of TiO2-containing mortars coated with diesel soot has been appraised under laboratory conditions. The mortar samples were manufactured using lime putty and two different doses of TiO2 (2.5% and 5%). The lime mortars were then coated with diesel engine soot and irradiated with ultraviolet A (UVA) illumination for 30days. The photocatalytic efficiency was evaluated by visual inspection, field emission scanning electron microscopy (FESEM) and colour spectrophotometry. Changes in the chemical composition of the soot particles (including persistent organic pollutants) were assessed by analytical pyrolysis (Py-GC/MS) and solid state (13)C NMR spectroscopy. The FESEM and colour spectrophotometry revealed that the soot-coated TiO2-containing mortars promoted a self-cleaning effect after UVA irradiation. The combination of analytical pyrolysis and (13)C solid state NMR showed that the UVA irradiation caused the cracking of polycyclic aromatic structures and n-alkyl compounds of the diesel soot and its transformation into methyl polymers. Our findings also revealed that the inclusion of TiO2 in the lime mortar formulations catalysed these transformations promoting the self-cleaning of the soot-stained mortars. The combined action of TiO2 and UVA irradiation is a promising proxy to clean lime mortars affected by soot deposition. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. UVA-riboflavin photochemical therapy of bacterial keratitis: a pilot study.

    PubMed

    Makdoumi, Karim; Mortensen, Jes; Sorkhabi, Omid; Malmvall, Bo-Eric; Crafoord, Sven

    2012-01-01

    The aim of this work as to investigate the photochemical interaction used in corneal crosslinking (CXL) as the primary therapy for bacterial keratitis. A prospective non-randomized study was conducted including 16 patients with a clinical diagnosis of bacterial keratitis. No patient had any prior antibiotic treatment for the current infection. Photography and microbial culturing of the infected cornea were performed. Riboflavin was topically administered for 20 min and ultraviolet light (UVA) exposure settings for treatment of keratoconus were used. After the procedure, clinical examinations were done at least once daily until signs of improvement had been established. The frequency of examinations was thereafter reduced. Antibiotic therapy was initiated if infectious progression was suspected. The trial was registered at ISCRTN.org (no: 21432643). All eyes responded to the photochemical treatment with improvement in symptoms and signs of reduced inflammation. Epithelial healing was achieved in all cases. Antibiotic administration was necessary in two cases. One patient required a human amniotic membrane transplant. This trial illustrates that photosensitization of riboflavin using UVA at 365 nm has the potential to induce healing in patients with microbial keratitis. The results from the treatment of these 16 patients with corneal ulcers indicate that UVA-riboflavin photochemical therapy merits a controlled study in order to assess its efficacy and safety compared to antibiotics.

  18. 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

  19. Antioxidant Activity of Caffeic Acid through a Novel Mechanism under UVA Irradiation

    PubMed Central

    Mori, Hiroko; Iwahashi, Hideo

    2009-01-01

    Effect of caffeic acid on the formation of hydroxyl radicals was examined during xanthone-mediated photosensitization. The reaction was performed on irradiation (λ = 365 nm) of the standard reaction mixture containing 15 µM xanthone, 0.1 M 5,5-dimethyl-1-pyrroline N-oxide (DMPO) and 20 mM phosphate buffer (pH 7.4) using electron paramagnetic resonance (EPR) with spin trapping. Caffeic acid inhibited the formation of hydroxyl radicals. Caffeic acid hardly scavenged both hydroxyl radicals and superoxide radicals under conditions employed in this paper in spite of its ability to act as a hydrogen donor or a reagent for the aromatic hydroxylation, because high concentration of DMPO trapped hydroxyl radicals overwhelmingly. Furthermore, caffeic acid inhibited the formation of hydroxyl radicals in the standard reaction mixture with EDTA under UVA irradiation. Accordingly, the inhibitory effect of caffeic acid on the formation of hydroxyl radicals in the standard reaction mixture under UVA irradiation is not due to its ability to chelate iron. Thus, the inhibitory effect of caffeic acid seems to occur in the standard reaction mixture under UVA irradiation through a novel antioxidation activity, i.e., ability to quench the exited xanthone. PMID:19590707

  20. Photo-Fenton treatment of valproate under UVC, UVA and simulated solar radiation.

    PubMed

    Funai, Daniel Haranaka; Didier, Florian; Giménez, Jaime; Esplugas, Santiago; Marco, Pilar; Machulek, Amilcar

    2017-02-05

    The abatement of valproic acid sodium salt (VA) via photo-Fenton process was investigated to evaluate the effect of irradiation type. Three different light sources have been used: UVA (black light blue lamps, BLB reactor), UVC (UVC reactor) and simulated sunlight in a Solarbox (SB). Using the highest concentrations of Fe(2+) (10mgL(-1)) and H2O2 (150mgL(-1)), 100% of VA degradation was observed in BLB and UVC devices, and 89.7% in Solarbox. Regarding mineralization, 67.4% and 76.4% of TOC conversion were achieved in BLB and UVC, respectively. In Solarbox, mineralization was negligible. Treated solutions under UVA or UVC radiation became biodegradable (BOD5/COD≥0.25), which was not observed in Solarbox where BOD5/COD achieved was only 0.20. Regarding to toxicity (Vibrio Fischeri method), all processes have promoted the overall toxicity reduction of VA solution. Transformation products were identified by a LC-ESI-TOF mass spectrometer, and degradation pathways were proposed. Operating costs and the energy needed by mg of VA removed were estimated and compared, for the different installations, showing that UVA can remove around 3 times more VA than SB and 2 times more VA than UVC, under the same conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. Terrestrial humic substances in Daliao River and its estuary: optical signatures and photoreactivity to UVA light.

    PubMed

    Chen, Hao; Lei, Kun; Wang, Xuechun

    2016-04-01

    Fluorescent dissolved organic matter (FDOM) components were identified by Parallel Factor Analysis (PARAFAC) in surface water of Daliao River and its estuary with a focus on terrestrial humic substance-(HS)-like FDOM identified under two contrasting hydrological conditions. The hydrological conditions did not have noticeable effect on the spectral features of the terrestrial HS-like FDOM, but did affect the components' intensities and photoreactivity: (1) the intensities of terrestrial HS-like components were higher in the normal flow period than in the high flow period, and (2) a spectrally similar terrestrial HS-like FDOM identified under the two contrasting hydrological conditions showed distinct photoreactivity to the same dose of UVA illumination. The findings indicated that terrestrial HS was generated at lower intensities at the terrestrial sources during the high flow period than during the normal flow period and that the transport of terrestrial HS material through the river-estuary system was affected dominantly by seawater dilution along the salinity gradient while fine-tuned by solar UVA illumination. This study exemplifies the effect of hydrological conditions on optical signatures of terrestrial HS-like FDOM and their photoreactivity towards UVA illumination, improving our understanding of the dynamics of terrestrial HS material in river-estuary systems in the framework of the currently proposed new conceptual model for terrestrial organic matter.

  6. 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.

  7. 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. © 2011 Wiley Periodicals, Inc. Photochemistry and Photobiology © 2011 The American Society of Photobiology.

  8. 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.

  9. Photocarcinogenesis in the Tg.AC mouse: lomefloxacin and 8-methoxypsoralen.

    PubMed

    Chignell, C F; Haseman, J K; Sik, R H; Tennant, R W; Trempus, C S

    2003-01-01

    The Tg.AC mouse is a good predictor of carcinogenic potential when the test article is administered by dorsal painting (Tennant et al. (1995) Environ. Health Perspect. 103, 942). We have used lomefloxacin (LOME) and 8-methoxypsoralen (8-MOP) in combination with UVA to determine whether the Tg.AC transgenic mouse also responds to parenterally administered photocarcinogens. Female Tg.AC mice were given LOME (25 mg/kg intraperitoneal in normal saline) followed by UVA (25 J/cm2) 1-2 h later, five times every 2 weeks on a repetitive schedule. Other groups received LOME, UVA or vehicle alone. After 16 weeks, the mean numbers of papillomas/mouse +/- SD (% responding) were: saline, 0.3 +/- 0.5 (33%); UVA + saline, 1.3 +/- 0.6 (100%); LOME, 1.9 +/- 1.6 (86%) and LOME-UVA, 1.5 +/- 1.9 (64%). Only the 100% incidence of tumors in the UVA group and the maximum tumor yields in the LOME and UVA groups are significant (P < 0.05) when compared with the control. In a second study, Tg.AC mice were administered the classical photocarcinogen 8-MOP (8 mg/kg intragastric in corn oil) followed by 2 J/cm2 UVA 1-2 h later, five times every 2 weeks on a repetitive schedule. The second group received 8-MOP, whereas the third was exposed to UVA alone. Papillomas began to appear at 2 weeks in the 8-MOP-UVA group, and after 17 weeks the mean numbers of papillomas/mouse +/- SD (% responding) were: 8-MOP-UVA, 6.9 +/- 8.6 (93%); UVA + corn oil, 1.1 +/- 1.2 (69%) and 8-MOP, 1.1 +/- 1.6 (50%). The maximum tumor yield in the 8-MOP-UVA group was significantly higher (P < 0.01) than that in the other two groups. Our findings suggest that more studies need to be done before the Tg.AC mouse can be used with confidence to identify parenterally administered photocarcinogens.

  10. MAS C-Terminal Tail Interacting Proteins Identified by Mass Spectrometry- Based Proteomic Approach

    PubMed Central

    Tirupula, Kalyan C.; Zhang, Dongmei; Osbourne, Appledene; Chatterjee, Arunachal; Desnoyer, Russ; Willard, Belinda; Karnik, Sadashiva S.

    2015-01-01

    Propagation of signals from G protein-coupled receptors (GPCRs) in cells is primarily mediated by protein-protein interactions. MAS is a GPCR that was initially discovered as an oncogene and is now known to play an important role in cardiovascular physiology. Current literature suggests that MAS interacts with common heterotrimeric G-proteins, but MAS interaction with proteins which might mediate G protein-independent or atypical signaling is unknown. In this study we hypothesized that MAS C-terminal tail (Ct) is a major determinant of receptor-scaffold protein interactions mediating MAS signaling. Mass-spectrometry based proteomic analysis was used to comprehensively identify the proteins that interact with MAS Ct comprising the PDZ-binding motif (PDZ-BM). We identified both PDZ and non-PDZ proteins from human embryonic kidney cell line, mouse atrial cardiomyocyte cell line and human heart tissue to interact specifically with MAS Ct. For the first time our study provides a panel of PDZ and other proteins that potentially interact with MAS with high significance. A ‘cardiac-specific finger print’ of MAS interacting PDZ proteins was identified which includes DLG1, MAGI1 and SNTA. Cell based experiments with wild-type and mutant MAS lacking the PDZ-BM validated MAS interaction with PDZ proteins DLG1 and TJP2. Bioinformatics analysis suggested well-known multi-protein scaffold complexes involved in nitric oxide signaling (NOS), cell-cell signaling of neuromuscular junctions, synapses and epithelial cells. Majority of these protein hits were predicted to be part of disease categories comprising cancers and malignant tumors. We propose a ‘MAS-signalosome’ model to stimulate further research in understanding the molecular mechanism of MAS function. Identifying hierarchy of interactions of ‘signalosome’ components with MAS will be a necessary step in future to fully understand the physiological and pathological functions of this enigmatic receptor. PMID

  11. MAS C-Terminal Tail Interacting Proteins Identified by Mass Spectrometry- Based Proteomic Approach.

    PubMed

    Tirupula, Kalyan C; Zhang, Dongmei; Osbourne, Appledene; Chatterjee, Arunachal; Desnoyer, Russ; Willard, Belinda; Karnik, Sadashiva S

    2015-01-01

    Propagation of signals from G protein-coupled receptors (GPCRs) in cells is primarily mediated by protein-protein interactions. MAS is a GPCR that was initially discovered as an oncogene and is now known to play an important role in cardiovascular physiology. Current literature suggests that MAS interacts with common heterotrimeric G-proteins, but MAS interaction with proteins which might mediate G protein-independent or atypical signaling is unknown. In this study we hypothesized that MAS C-terminal tail (Ct) is a major determinant of receptor-scaffold protein interactions mediating MAS signaling. Mass-spectrometry based proteomic analysis was used to comprehensively identify the proteins that interact with MAS Ct comprising the PDZ-binding motif (PDZ-BM). We identified both PDZ and non-PDZ proteins from human embryonic kidney cell line, mouse atrial cardiomyocyte cell line and human heart tissue to interact specifically with MAS Ct. For the first time our study provides a panel of PDZ and other proteins that potentially interact with MAS with high significance. A 'cardiac-specific finger print' of MAS interacting PDZ proteins was identified which includes DLG1, MAGI1 and SNTA. Cell based experiments with wild-type and mutant MAS lacking the PDZ-BM validated MAS interaction with PDZ proteins DLG1 and TJP2. Bioinformatics analysis suggested well-known multi-protein scaffold complexes involved in nitric oxide signaling (NOS), cell-cell signaling of neuromuscular junctions, synapses and epithelial cells. Majority of these protein hits were predicted to be part of disease categories comprising cancers and malignant tumors. We propose a 'MAS-signalosome' model to stimulate further research in understanding the molecular mechanism of MAS function. Identifying hierarchy of interactions of 'signalosome' components with MAS will be a necessary step in future to fully understand the physiological and pathological functions of this enigmatic receptor.

  12. Validation of commercial Mas receptor antibodies for utilization in Western Blotting, immunofluorescence and immunohistochemistry studies.

    PubMed

    Burghi, Valeria; Fernández, Natalia Cristina; Gándola, Yamila Belén; Piazza, Verónica Gabriela; Quiroga, Diego Tomás; Guilhen Mario, Érica; Felix Braga, Janaína; Bader, Michael; Santos, Robson Augusto Souza; Dominici, Fernando Pablo; Muñoz, Marina Cecilia

    2017-01-01

    Mas receptor (MasR) is a G protein-coupled receptor proposed as a candidate for mediating the angiotensin (Ang)-converting enzyme 2-Ang (1-7) protective axis of renin-angiotensin system. Because the role of this receptor is not definitively clarified, determination of MasR tissue distribution and expression levels constitutes a critical knowledge to fully understanding its function. Commercially available antibodies have been widely employed for MasR protein localization and quantification, but they have not been adequately validated. In this study, we carried on an exhaustive evaluation of four commercial MasR antibodies, following previously established criteria. Western Blotting (WB) and immunohistochemistry studies starting from hearts and kidneys from wild type (WT) mice revealed that antibodies raised against different MasR domains yielded different patterns of reactivity. Furthermore, staining patterns appeared identical in samples from MasR knockout (MasR-KO) mice. We verified by polymerase chain reaction analysis that the MasR-KO mice used were truly deficient in this receptor as MAS transcripts were undetectable in either heart or kidney from this animal model. In addition, we evaluated the ability of the antibodies to detect the human c-myc-tagged MasR overexpressed in human embryonic kidney cells. Three antibodies were capable of detecting the MasR either by WB or by immunofluorescence, reproducing the patterns obtained with an anti c-myc antibody. In conclusion, although three of the selected antibodies were able to detect MasR protein at high expression levels observed in a transfected cell line, they failed to detect this receptor in mice tissues at physiological expression levels. As a consequence, validated antibodies that can recognize and detect the MasR at physiological levels are still lacking.

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 8-methoxypsoralen reduces AKT phosphorylation, induces intrinsic and extrinsic apoptotic pathways, and suppresses cell growth of SK-N-AS neuroblastoma and SW620 metastatic colon cancer cells.

    PubMed

    Bartnik, Magdalena; Sławińska-Brych, Adrianna; Żurek, Aleksandra; Kandefer-Szerszeń, Martyna; Zdzisińska, Barbara

    2017-07-31

    8-methoxypsoralen (8-MOP) is a furanocoumarin and an active compound of a traditional Egyptian medicinal plant Ammi majus L, whose juice/fruit has been used for many years in folk phototherapy for the treatment of vitiligo or a hyperproliferative skin disorder, psoriasis. 8-MOP together with UVA light is also used as an anticancer drug for the treatment of cutaneous T-cell lymphoma. However, furanocoumarins exert anticancer activity even without UV irradiation. Evaluation UV-independent anticancer activity of 8-MOP in human cancer cell lines and identification of the mechanisms involved in this action. Results could provide new data about a potential role of 8-MOP in prevention and growth suppression in a broad spectrum of cancers. 8-MOP (99%, HPLC/MS assay) was isolated from A. majus fruits by chromatographic methods. The effect of 8-MOP on cell viability was evaluated by the MTT test in several human cancer cell lines. Anti-proliferative activity of 8-MOP was evaluated by the BrdU assay in neuroblastoma (SK-N-AS) and metastatic colon cancer (SW620) cells. The Hoechst/PI staining was used for morphological analysis of cell death. An annexin V-FITC/PI double labelling and Cell Death Detection ELISA kit were used to detect apoptosis. The expression of apoptosis-associated proteins and the AKT activation status were determined by Western blot analysis. 8-MOP inhibited cell growth in several cancer cell lines. The SK-N-AS and SW620 cells were the most sensitive to the compound. 8-MOP reduced the phosphorylation of AKT(308), decreased the expression of Bcl-2, increased the Bax protein level, and activated caspases -8, -9, and -3 in both cell lines. 8-MOP impairs the PI3K/AKT signalling pathway and, independently of photoactivation, can inhibit the growth of neuroblastoma and colon cancer cells by induction of apoptosis via intrinsic and extrinsic pathways. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.

  18. MODIS Airborne simulator (MAS) Final Report for CLASIC

    SciTech Connect

    Thomas Arnold; Steven Platnick

    2010-11-24

    The MAS was flown aboard the NASA ER-2 for the CLASIC field experiment, and for all data collected, provided calibrated and geolocated (Level-1B) radiance data for it’s 50 spectral bands (ranging in wavelength for 0.47 to 14.3 µm). From the Level-1B data, as directed in the Statement of Work, higher order (Level-2) data products were derived. The Level-2 products include: a) cloud optical thickness, b) cloud effective radius, c) cloud top height (temperature), d) cloud fraction, e) cloud phase products. Preliminary Level-1B and Level-2 products were provided during the field experiment (typically within one or two days of data collection). Final version data products were made available in December 2008 following considerable calibration analysis. Data collection, data processing (to Level-2), and discussion of the calibration work are summarized below.

  19. Food Waste Composting Study from Makanan Ringan Mas

    NASA Astrophysics Data System (ADS)

    Kadir, A. A.; Ismail, S. N. M.; Jamaludin, S. N.

    2016-07-01

    The poor management of municipal solid waste in Malaysia has worsened over the years especially on food waste. Food waste represents almost 60% of the total municipal solid waste disposed in the landfill. Composting is one of low cost alternative method to dispose the food waste. This study is conducted to compost the food waste generation in Makanan Ringan Mas, which is a medium scale industry in Parit Kuari Darat due to the lack knowledge and exposure of food waste recycling practice. The aim of this study is to identify the physical and chemical parameters of composting food waste from Makanan Ringan Mas. The physical parameters were tested for temperature and pH value and the chemical parameter are Nitrogen, Phosphorus and Potassium. In this study, backyard composting was conducted with 6 reactors. Tapioca peel was used as fermentation liquid and soil and coconut grated were used as the fermentation bed. Backyard composting was conducted with six reactors. The overall results from the study showed that the temperature of the reactors were within the range which are from 30° to 50°C. The result of this study revealed that all the reactors which contain processed food waste tend to produce pH value within the range of 5 to 6 which can be categorized as slightly acidic. Meanwhile, the reactors which contained raw food waste tend to produce pH value within the range of 7 to 8 which can be categorized as neutral. The highest NPK obtained is from Reactor B that process only raw food waste. The average value of Nitrogen is 48540 mg/L, Phosphorus is 410 mg/L and Potassium is 1550 mg/L. From the comparison with common chemical fertilizer, it shows that NPK value from the composting are much lower than NPK of the common chemical fertilizer. However, comparison with NPK of organic fertilizer shown only slightly difference value in NPK.

  20. Multiple non-coding exons and alternative splicing in the mouse Mas protooncogene.

    PubMed

    Alenina, Natalia; Böhme, Ilka; Bader, Michael; Walther, Thomas

    2015-09-01

    The Mas protooncogene encodes a G protein-coupled receptor with the common seven transmembrane domains, expressed mainly in the testis and brain. We provided evidence that Mas is a functional angiotensin-(1-7) receptor and can interact with the angiotensin II type 1 (AT1) receptor. The gene is transcriptionally regulated during development in the brain and testis, but its structure was unresolved. In this study we used 5'- and 3'-RACE, RT-PCR, and RNase-protection assays to elucidate the complete Mas gene structure and organization. We identified 12 exons in the mouse Mas gene with 11 in the 5' untranslated mRNA, which can be alternatively spliced. We also showed that Mas transcription can start from 4 tissue-specific promoters, whereby testis-specific Mas mRNA is transcribed from two upstream promoters, and the expression of Mas in the brain starts from two downstream promoters. Alternative splicing and multiple promoter usage result in at least 12 Mas transcripts in which different 5' untranslated regions are fused to a common coding sequence. Moreover, termination of Mas mRNA is regulated by two different polyadenylation signals. The gene spans approximately 27 kb, and the longest detected mRNA contains 2,451 bp. Thus, our results characterize the Mas protooncogene as the gene with the most complex gene structure of all described members of the gene family coding for G protein-coupled receptors. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Angiotensin-(1-7)/Mas axis modulates fear memory and extinction in mice.

    PubMed

    Lazaroni, Thiago Luiz do Nascimento; Bastos, Cristiane Perácio; Moraes, Márcio Flávio Dutra; Santos, Robson Souza; Pereira, Grace Schenatto

    2016-01-01

    Inappropriate defense-alerting reaction to fear is a common feature of neuropsychiatric diseases. Therefore, impairments in brain circuits, as well as in molecular pathways underlying the neurovegetative adjustments to fear may play an essential role on developing neuropsychiatric disorders. Here we tested the hypothesis that interfering with angiotensin-(1-7) [Ang-(1-7)]/Mas receptor axis homeostasis, which appears to be essential to arterial pressure control, would affect fear memory and extinction. Mas knockout (MasKO) mice, in FVB/N background, showed normal cued fear memory and extinction, but increased freezing in response to context. Next, as FVB/N has poor performance in contextual fear memory, we tested MasKO in mixed 129xC57BL/6 background. MasKO mice behaved similarly to wild-type (WT), but memory extinction was slower in contextual fear conditioning to a weak protocol (1CS/US). In addition, delayed extinction in MasKO mice was even more pronounced after a stronger protocol (3CS/US). We showed previously that Angiotensin II receptor AT1 antagonist, losantan, rescued object recognition memory deficit in MasKO mice. Here, losartan was also effective. Memory extinction was accelerated in MasKO mice after treatment with losartan. In conclusion, we showed for the first time that Ang-(1-7)/Mas axis may modulate fear memory extinction. Furthermore, we suggest MasKO mice as an animal model to study post-traumatic stress disorder (PTSD).

  2. Chronic allergic pulmonary inflammation is aggravated in angiotensin-(1-7) Mas receptor knockout mice.

    PubMed

    Magalhães, Giselle S; Rodrigues-Machado, Maria Glória; Motta-Santos, Daisy; Alenina, Natalia; Bader, Michael; Santos, Robson A; Barcelos, Lucíola S; Campagnole-Santos, Maria José

    2016-12-01

    The angiotensin-(1-7) [ANG-(1-7)]/Mas receptor pathway is currently recognized as a counterbalancing mechanism of the renin-angiotensin system in different pathophysiological conditions. We have previously described that treatment with ANG-(1-7) attenuates lung inflammation and remodeling in an experimental model of asthma. In the present study, we investigated whether lack of the Mas receptor could alter the inflammatory response in a model of chronic allergic lung inflammation induced by ovalbumin (OVA). Mas receptor wild-type (MasWT) and knockout (MasKO) mice were subjected to four doses of OVA (20 μg/mice ip) with a 14-day interval. At the 21st day, nebulization with OVA (1%) was started, three times per week until the 46th day. Control groups received saline (0.9% ip) and were nebulized with saline (0.9%). MasWT-OVA developed a modest inflammatory response and minor pulmonary remodeling to OVA challenge. Strikingly, MasKO-OVA presented a significant increase in inflammatory cell infiltrate, increase in extracellular matrix deposition, increase in thickening of the alveolar parenchyma, increase in thickening of the smooth muscle layer of the pulmonary arterioles, increase in proinflammatory cytokine and chemokine levels in the lungs, characteristic of chronic asthma. Additionally, MasKO-OVA presented an increase in ERK1/2 phosphorylation compared with MasWT-OVA. Furthermore, MasKO-OVA showed a worse performance in a test of maximum physical exercise compared with MasWT-OVA. Our study shows that effects triggered by the Mas receptor are important to attenuate the inflammatory and remodeling processes in a model of allergic lung inflammation in mice. Our data indicate that impairment of the ANG-(1-7)/Mas receptor pathway may lead to worsening of the pathophysiological changes of asthma. Copyright © 2016 the American Physiological Society.

  3. Reverse Induced Fit-Driven MAS-Downstream Transduction: Looking for Metabotropic Agonists.

    PubMed

    Pernomian, Larissa; Gomes, Mayara Santos; de Paula da Silva, Carlos Henrique Tomich; Campos, Joaquin

    2017-09-11

    The protective effects assigned to MAS receptors activation have spurred a great interest in the development of MAS agonists for clinical purposes. However, the current bases that drive the design of these ligands preclude important concepts recently addressed for MAS activation. Emerging data confirmed that physiological concentrations of peptide MAS agonists induce an atypical signaling that does not reach the metabotropic efficacy of constitutive MAS activation. The canonical activation of MAS-coupled G proteins is only achieved by supraphysiological concentrations of peptide MAS agonists or physiological concentrations of chemically modified analogues. These pleiotropic differences are because of two overlapped but non-identical ligand binding domains (LBD): one non-metabotropic site that recognizes peptide agonists and one metabotropic domain that recognizes modified analogues. Accordingly, it is feasible that supraphysiological concentrations of peptide MAS agonists undergo to chemical modifications that make them suitable for binding to the metabotropic LBD. Recent advances on Receptor Theory confirmed that G protein-coupled receptor (GPCR) oligomerization enhances pharmacological parameters coupled to metabotropic signaling from GPCR ligands, including MAS agonists. For instance, the formation of GPCR-signalosome complex (higher order heteroligomers of GPCR involved in signaling crosstalk) makes the transduction of agonists a more adaptive signal. Considering the recent identification of MAS-signalosome, we postulate the reverse induced fit hypothesis in which MAS-signalosome would trigger chemical modifications required for agonists bind to the metabotropic MAS/LBD. In view of this hypothesis, we cover rational perspectives that consider this information for the development of novel metabotropic MAS agonists provided with constitutive efficacy at physiological concentrations. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  4. Modulation of antioxidant defense by Alpinia galanga and Curcuma aromatica extracts correlates with their inhibition of UVA-induced melanogenesis.

    PubMed

    Panich, Uraiwan; Kongtaphan, Kamolratana; Onkoksoong, Tassanee; Jaemsak, Kannika; Phadungrakwittaya, Rattana; Thaworn, Athiwat; Akarasereenont, Pravit; Wongkajornsilp, Adisak

    2010-04-01

    Ultraviolet A (UVA) irradiation is suggested to contribute to melanogenesis through promoting cellular oxidative stress and impairing antioxidant defenses. An overproduction of melanin can be associated with melanoma skin cancer and hyperpigmentation. Therefore, developing effective antimelanogenic agents is of importance. Alpinia galanga (AG) and Curcuma aromatica (CA) are traditional medicinal plants widely used for skin problems. Hence, this study investigated the antimelanogenic effects of AG and CA extracts (3.8-30 microg/ml) by assessing tyrosinase activity, tyrosinase mRNA levels, and melanin content in human melanoma cells (G361) exposed to UVA. The roles in protecting against melanogenesis were examined by evaluating their inhibitory effects on UVA-induced cellular oxidative stress and modulation of antioxidant defenses including antioxidant enzymes, catalase (CAT) and glutathione peroxidase (GPx), and intracellular glutathione (GSH). In addition, possible active compounds accountable for biological activities of the extracts were identified by thin layer chromatography (TLC)-densitometric analysis. Our study demonstrated that UVA (8 J/cm(2)) induced both tyrosinase activity and mRNA levels and UVA (16 J/cm(2))-mediated melanin production were suppressed by the AG or CA extracts at noncytotoxic concentrations. Both extracts were able to protect against UVA-induced cellular oxidant formation and depletion of CAT and GPx activities and GSH content in a dose-dependent manner. Moreover, TLC-densitometric analysis detected the presence of eugenol and curcuminoids in AG and CA, respectively. This is the first report representing promising findings on AG and CA extract-derived antityrosinase properties correlated with their antioxidant potential. Inhibiting cellular oxidative stress and improving antioxidant defenses might be the mechanisms by which the extracts yield the protective effects on UVA-dependent melanogenesis.

  5. 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

  6. The Antithrombotic Effect of Angiotensin-(1–7) Involves Mas-Mediated NO Release from Platelets

    PubMed Central

    Fraga-Silva, Rodrigo Araújo; Pinheiro, Sergio Veloso Brant; Gonçalves, Andrey Christian Costa; Alenina, Nathalia; Bader, Michael; Santos, Robson Augusto Souza

    2008-01-01

    The antithrombotic effect of angiotensin(Ang)-(1–7) has been reported, but the mechanism of this effect is not known. We investigated the participation of platelets and receptor Mas-related mechanisms in this action. We used Western blotting to test for the presence of Mas protein in rat platelets and used fluorescent-labeled FAM-Ang-(1–7) to determine the specific binding for Ang-(1–7) and its displacement by the receptor Mas antagonist A-779 in rat platelets and in Mas−/ − and Mas+/+ mice platelets. To test whether Ang-(1–7) induces NO release from platelets, we used the NO indicator DAF-FM. In addition we examined the role of Mas in the Ang-(1–7) antithrombotic effect on induced thrombi in the vena cava of male Mas−/ − and Mas+/+ mice. The functional relevance of Mas in hemostasis was evaluated by determining bleeding time in Mas+/+ and Mas−/ − mice. We observed the presence of Mas protein in platelets, as indicated by Western Blot, and displacement of the binding of fluorescent Ang-(1–7) to rat platelets by A-779. Furthermore, in Mas+/+ mouse platelets we found specific binding for Ang-(1–7), which was absent in Mas−/ − mouse platelets. Ang-(1–7) released NO from rat and Mas+/+ mouse platelets, and A-779 blocked this effect. The NO release stimulated by Ang-(1–7) was abolished in Mas−/ − mouse platelets. Ang-(1–7) inhibited thrombus formation in Mas+/+ mice. Strikingly, this effect was abolished in Mas−/ −mice. Moreover, Mas deficiency resulted in a significant decrease in bleeding time (8.50 ± 1.47 vs. 4.28 ± 0.66 min). This study is the first to show the presence of Mas protein and specific binding for Ang-(1–7) in rat and mouse platelets. Our data also suggest that the Ang-(1–7) antithrombotic effect involves Mas-mediated NO release from platelets. More importantly, we showed that the antithrombotic effect of Ang-(1–7) in vivo is Mas dependent and that Mas is functionally important in hemostasis. PMID

  7. Combination of 8-methoxypsoralen and ultraviolet A inhibits smooth muscle proliferation in vitro and in vivo after angioplasty

    NASA Astrophysics Data System (ADS)

    March, Keith L.; Spaedy, Tony J.; Aita, Michael; Wilensky, Robert L.; Gradus-Pizlo, Ionina; Hathaway, David R.

    1994-07-01

    Smooth muscle cell proliferation plays a major role in restenosis following angioplasty. We have studied the effects of ultraviolet A (UVA) activation of 8-methoxypsoralen (8-MOP) on cultured SMC as well as atherosclerotic rabbit femoral arteries following angioplasty. 8-MOP and UVA display synergistic proliferation inhibition of cultured SMC in a cell-cycle independent manner. At intermediate doses, a cytostatic effect was seen over a 28 day period following a single exposure. In conclusion, a combination of 8-MOP and UVA significantly lowered SMC proliferation and cellularity in cell culture as well as in the neointima and media after balloon-induced vascular injury in the atherosclerotic rabbit model. This approach of systemic administration and local activation is feasible and offers a potential therapy for restenosis.

  8. 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).

  9. 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

  10. 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

  11. 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.

  12. 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.

  13. Influence of UV-A radiation on oxidative stress and antioxidant enzymes in Mythimna separata (Lepidoptera: Noctuidae).

    PubMed

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

    2017-03-01

    Abiotic stress factors, including ultraviolet (UV) radiation, significantly affect insect life. UV-A radiation (320-400 nm) has been widely used for insect control since it increases the production of ROS and causes oxidative cell damage. In the present study, we evaluated the effects of UV-A irradiation on an important pest in China, the ear-cutting caterpillar, Mythimna separata (Lepidoptera: Noctuidae). We exposed 3-day-old M. separata adults to UV-A radiation for different periods of time (0, 30, 60, 90, and 120 min) and evaluated the resulting total antioxidant capacity and the activity of the antioxidant enzymes superoxide dismutase, catalase, peroxidase, and glutathione-S-transferase. The total antioxidant capacity significantly increased after exposure to UV-A radiation for 60 min but decreased after 90 and 120 min of exposure, compared with the control. The antioxidant activity of glutathione-S-transferase, superoxide dismutase, catalase, and peroxidase increased after 60-min exposure, and it was decreased at the longest exposure period 120 min. The longest exposure time period relatively activates the xenobiotic detoxifying enzymes like glutathione-S-transferase, superoxide dismutase, catalase, and peroxidase enzymes. The longest duration of UV-A radiation may cooperate with pesticide detoxification mechanism in insects, making them more susceptible to insecticides. Our results demonstrated that UV irradiation causes oxidative stress, affects the activity of antioxidant enzymes, and disturbs the physiology of M. separata adults.

  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. Mycorrhiza of the host-specific Lactarius deterrimus on the roots of Picea abies and Arctostaphylos uva-ursi.

    PubMed

    Mühlmann, O; Göbl, F

    2006-06-01

    The ectomycorrhizal basidiomycete species Lactarius deterrimus Gröger is considered to be a strictly host-specific mycobiont of Picea abies (L.) Karst. However, we identified arbutoid mycorrhiza formed by this fungus on the roots of Arctostaphylos uva-ursi (L.) Spreng. in a mixed stand at the alpine timberline; typical ectomycorrhiza of P. abies were found in close relation. A. uva-ursi is known as an extremely unspecific phytobiont. The mycorrhizae of both associations are described and compared morphologically. The mycorrhiza formed by L. deterrimus on both A. uva-ursi and P. abies show typical ectomycorrhizal features such as a hyphal mantle and a Hartig net. The main difference between the mycorrhizal symbioses with the different phytobionts is the occurrence of intracellular hyphae in the epidermal cells of A. uva-ursi. This emphasizes the importance of the plant partner for mycorrhizal anatomy. This is the first report of a previously considered host-specific ectomycorrhizal fungus in association with A. uva-ursi under natural conditions. The advantages of this loose specificity between the fungus and plant species is discussed.

  16. 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.

  17. 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.

  18. Evidence for Heterodimerization and Functional Interaction of the Angiotensin Type 2 Receptor and the Receptor MAS.

    PubMed

    Leonhardt, Julia; Villela, Daniel C; Teichmann, Anke; Münter, Lisa-Marie; Mayer, Magnus C; Mardahl, Maibritt; Kirsch, Sebastian; Namsolleck, Pawel; Lucht, Kristin; Benz, Verena; Alenina, Natalia; Daniell, Nicholas; Horiuchi, Masatsugu; Iwai, Masaru; Multhaup, Gerhard; Schülein, Ralf; Bader, Michael; Santos, Robson A; Unger, Thomas; Steckelings, Ulrike Muscha

    2017-06-01

    The angiotensin type 2 receptor (AT2R) and the receptor MAS are receptors of the protective arm of the renin-angiotensin system. They mediate strikingly similar actions. Moreover, in various studies, AT2R antagonists blocked the effects of MAS agonists and vice versa. Such cross-inhibition may indicate heterodimerization of these receptors. Therefore, this study investigated the molecular and functional interplay between MAS and the AT2R. Molecular interactions were assessed by fluorescence resonance energy transfer and by cross correlation spectroscopy in human embryonic kidney-293 cells transfected with vectors encoding fluorophore-tagged MAS or AT2R. Functional interaction of AT2R and MAS was studied in astrocytes with CX3C chemokine receptor-1 messenger RNA expression as readout. Coexpression of fluorophore-tagged AT2R and MAS resulted in a fluorescence resonance energy transfer efficiency of 10.8 ± 0.8%, indicating that AT2R and MAS are capable to form heterodimers. Heterodimerization was verified by competition experiments using untagged AT2R and MAS. Specificity of dimerization of AT2R and MAS was supported by lack of dimerization with the transient receptor potential cation channel, subfamily C-member 6. Dimerization of the AT2R was abolished when it was mutated at cysteine residue 35. AT2R and MAS stimulation with the respective agonists, Compound 21 or angiotensin-(1-7), significantly induced CX3C chemokine receptor-1 messenger RNA expression. Effects of each agonist were blocked by an AT2R antagonist (PD123319) and also by a MAS antagonist (A-779). Knockout of a single of these receptors made astrocytes unresponsive for both agonists. Our results suggest that MAS and the AT2R form heterodimers and that-at least in astrocytes-both receptors functionally depend on each other. © 2017 American Heart Association, Inc.

  19. 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.

  20. [Biologically active substances of cornelian cherry fruits (Cornus mas L.)].

    PubMed

    Perova, I B; Zhogova, A A; Poliakova, A V; Éller, K I; Ramenskaia, G V; Samylina, I A

    2014-01-01

    10 samples of fresh-frozen cornelian cherry fruits (Cornus mas L.), collected in the Tambov and the Caucasus regions, were investigated for the total amount and composition of the main biologically active substances (BAS): anthocyanins (AC), proanthocyanidins (OPC), dihydroxycinnamic acids (DHCA), iridoids, organic acids, mono- and disaccharides and antiradical activity in the DPPH-test in vitro. Total phenolics content determined by Folin-Ciocalteu method, was 150-400 mg/100 g fresh fruit weight. The OPC content, estimated by Bate-Smith method, varied from 20-25 mg/100 g of unripe cornelian cherries to 80-430 mg/100 g of mature cornelian cherries. Total AC amount evaluated by pH-differential spectrophotometry was minimal in unripe fruits (11,2 mg/100 g), and maximal in mature fruits (92,2 mg/100 g). Profile of individual AC was determined by HPLC with UV/Vis and ESI-TOF-MS detections. 3-galactosides of cyanidin (19,0-80,3%) and pelargonidin (15,1-75,6%) were found as main anthocyanins. An original methodology for iridoid determination based on HPLC with UV and ESI-TOF-MS detection was developed. The main iridoids were identified as loganic acid, loganin, sweroside and cornuside. Total iridoids content was 130-400 mg/100 g, and loganic acid was predominant in all samples (87,6-94,8%). Only minor amount of the DHCA derivatives (<10 mg/100 g) were found. The malic acid was predominant among organic acids, the total content of which varied from 0,4 to 2,8%. Relatively high amount of ascorbic acid (35-60 mg/100 g) was found. The carbohydrates profile of cornielian cherries was represented by fructose (2,2-3,8%) and glucose (2,5-7,0%). 70% water-ethanol extracts of Cornus mas fruits have showed pronounced antiradical activity in DPPH-test (470,5-932,0 mg TE/100 g). The data on specific minor BAS can be used in the standardization and evaluation of potential biological activity of extracts and dietary supplements based on the cornelian cherry fruits.

  1. Determination of minimal erythema dose and anomalous reactions to UVA radiation by skin phototype.

    PubMed

    Pérez Ferriols, A; Aguilera, J; Aguilera, P; de Argila, D; Barnadas, M A; de Cabo, X; Carrrascosa, J M; de Gálvez Aranda, M V; Gardeazábal, J; Giménez-Arnau, A; Lecha, M; Lorente, J; Martínez-Lozano, J A; Rodríguez Granados, M T; Sola, Y; Utrillas, M P

    2014-10-01

    Phototesting is a technique that assesses the skin's sensitivity to UV radiation by determining the smallest dose of radiation capable of inducing erythema (minimal erythema dose [MED]) and anomalous responses to UV-A radiation. No phototesting protocol guidelines have been published to date. This was a multicenter prospective cohort study in which 232 healthy volunteers were recruited at 9 hospitals. Phototests were carried out with solar simulators or fluorescent broadband UV-B lamps. Each individual received a total of 5 or 6 incremental doses of erythemal radiation and 4 doses of UV-A radiation. The results were read at 24hours. At hospitals where solar simulators were used, the mean (SD) MED values were 23 (8), 28 (4), 35 (4), and 51 (6) mJ/cm(2) for skin phototypes i to iv, respectively. At hospitals where broadband UV-B lamps were used, these values were 28 (5), 32 (3), and 34 (5) mJ/cm(2) for phototypes ii to iv, respectively. MED values lower than 7, 19, 27, and 38 mJ/cm(2) obtained with solar simulators were considered to indicate a pathologic response for phototypes I to IV, respectively. MED values lower than 18, 24, and 24mJ/cm(2) obtained with broadband UV-B lamps were considered to indicate a pathologic response for phototypes ii to iv, respectively. No anomalous responses were observed at UV-A radiation doses of up to 20J/cm(2). Results were homogeneous across centers, making it possible to standardize diagnostic phototesting for the various skin phototypes and establish threshold doses that define anomalous responses to UV radiation. Copyright © 2014 Elsevier España, S.L.U. y AEDV. All rights reserved.

  2. Photodynamic UVA-riboflavin bacterial elimination in antibiotic-resistant bacteria.

    PubMed

    Makdoumi, Karim; Bäckman, Anders

    2016-09-01

    To evaluate the bactericidal effect of clinical ultraviolet A (UVA) settings used in photoactivated chromophore for infectious keratitis (PACK)-collagen cross-linking (CXL) in antibiotic-resistant and non-resistant bacterial strains. Well-characterized bacterial strains from clinical isolates, without and with antibiotic resistance, were studied in a pairwise comparison. The evaluated pathogens were Staphylococcus epidermidis, Staphylococcus aureus, Pseudomonas aeruginosa, and Enterococcus faecalis. Bacteria were dispersed in PBS and diluted to a concentration of approximately 4 × 10(5) /ml. Riboflavin was added to a concentration of 0.01%. By spreading the solution on a microscope slide, a fluid film layer, with a thickness of around 400 mm, was formed and UVA exposure followed. Eight separate exposures were made for each strain (n = 8). The degree of elimination in resistant and non-resistant pathogens was compared. The bactericidal efficacy of exposure differed between the tested microorganisms, and the mean elimination ranged between 60 and 92%, being most extensive in both of the evaluated Pseudomonas strains and least in the E. faecalis strains. Similar reductions were seen in antibiotic-resistant and non-resistant strains, with the exception of S. aureus, in which the resistant strain metchicillin-resistant Staphylococcus aureus (MRSA) was eradicated in a greater extent than the non-resistant strain (P = 0.030). UVA-riboflavin settings used in PACK-CXL are effective in reducing both antibiotic-resistant and non-resistant bacteria. Antibiotic resistance does not appear to be protective against the photooxidative exposure. © 2016 Royal Australian and New Zealand College of Ophthalmologists.

  3. 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.

  4. 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. Copyright

  5. 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

  6. 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.

  7. 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.

  8. MAS-mediated antioxidant effects restore the functionality of angiotensin converting enzyme 2-angiotensin-(1-7)-MAS axis in diabetic rat carotid.

    PubMed

    Pernomian, Larissa; Gomes, Mayara Santos; Restini, Carolina Baraldi Araujo; de Oliveira, Ana Maria

    2014-01-01

    We hypothesized that endothelial AT1-activated NAD(P)H oxidase-driven generation of reactive oxygen species during type I-diabetes impairs carotid ACE2-angiotensin-(1-7)-Mas axis functionality, which accounts for the impaired carotid flow in diabetic rats. We also hypothesized that angiotensin-(1-7) chronic treatment of diabetic rats restores carotid ACE2-angiotensin-(1-7)-Mas axis functionality and carotid flow. Relaxant curves for angiotensin II or angiotensin-(1-7) were obtained in carotid from streptozotocin-induced diabetic rats. Superoxide or hydrogen peroxide levels were measured by flow cytometry in carotid endothelial cells. Carotid flow was also determined. We found that endothelial AT1-activated NAD(P)H oxidase-driven generation of superoxide and hydrogen peroxide in diabetic rat carotid impairs ACE2-angiotensin-(1-7)-Mas axis functionality, which reduces carotid flow. In this mechanism, hydrogen peroxide derived from superoxide dismutation inhibits ACE2 activity in generating angiotensin-(1-7) seemingly by activating I(Cl,SWELL0, while superoxide inhibits the nitrergic Mas-mediated vasorelaxation evoked by angiotensin-(1-7). Angiotensin-(1-7) treatment of diabetic rats restored carotid ACE2-angiotensin-(1-7)-Mas axis functionality by triggering a positive feedback played by endothelial Mas receptors, that blunts endothelial AT1-activated NAD(P)H oxidase-driven generation of reactive oxygen species. Mas-mediated antioxidant effects also restored diabetic rat carotid flow, pointing to the contribution of ACE2-angiotensin-(1-7)-Mas axis in maintaining carotid flow.

  9. Distributed Cooperation Solution Method of Complex System Based on MAS

    NASA Astrophysics Data System (ADS)

    Weijin, Jiang; Yuhui, Xu

    To adapt the model in reconfiguring fault diagnosing to dynamic environment and the needs of solving the tasks of complex system fully, the paper introduced multi-Agent and related technology to the complicated fault diagnosis, an integrated intelligent control system is studied in this paper. Based on the thought of the structure of diagnostic decision and hierarchy in modeling, based on multi-layer decomposition strategy of diagnosis task, a multi-agent synchronous diagnosis federation integrated different knowledge expression modes and inference mechanisms are presented, the functions of management agent, diagnosis agent and decision agent are analyzed, the organization and evolution of agents in the system are proposed, and the corresponding conflict resolution algorithm in given, Layered structure of abstract agent with public attributes is build. System architecture is realized based on MAS distributed layered blackboard. The real world application shows that the proposed control structure successfully solves the fault diagnose problem of the complex plant, and the special advantage in the distributed domain.

  10. Differential effects of Mas receptor deficiency on cardiac function and blood pressure in obese male and female mice.

    PubMed

    Wang, Yu; Shoemaker, Robin; Powell, David; Su, Wen; Thatcher, Sean; Cassis, Lisa

    2017-03-01

    Angiotensin-(1-7) [ANG-(1-7)] acts at Mas receptors (MasR) to oppose effects of angiotensin II (ANG II). Previous studies demonstrated that protection of female mice from obesity-induced hypertension was associated with increased systemic ANG-(1-7), whereas male obese hypertensive mice exhibited increased systemic ANG II. We hypothesized that MasR deficiency (MasR(-/-) ) augments obesity-induced hypertension in males and abolishes protection of females. Male and female wild-type (MasR(+/+) ) and MasR(-/-) mice were fed a low-fat (LF) or high-fat (HF) diet for 16 wk. MasR deficiency had no effect on obesity. At baseline, male and female MasR(-/-) mice had reduced ejection fraction (EF) and fractional shortening than MasR(+/+) mice. Male, but not female, HF-fed MasR(+/+) mice had increased systolic and diastolic (DBP) blood pressures compared with LF-fed controls. In HF-fed females, MasR deficiency increased DBP compared with LF-fed controls. In contrast, male HF-fed MasR(-/-) mice had lower DBP than MasR(+/+) mice. We quantified cardiac function after 1 mo of HF feeding in males of each genotype. HF-fed MasR(-/-) mice had higher left ventricular (LV) wall thickness than MasR(+/+) mice. Moreover, MasR(+/+) , but not MasR(-/-) , mice displayed reductions in EF from HF feeding that were reversed by ANG-(1-7) infusion. LV fibrosis was reduced in HF-fed MasR(+/+) but not MasR(-/-) ANG-(1-7)-infused mice. These results demonstrate that MasR deficiency promotes obesity-induced hypertension in females. In males, HF feeding reduced cardiac function, which was restored by ANG-(1-7) in MasR(+/+) but not MasR(-/-) mice. MasR agonists may be effective therapies for obesity-associated cardiovascular conditions.NEW & NOTEWORTHY MasR deficiency abolishes protection of female mice from obesity-induced hypertension. Male MasR-deficient obese mice have reduced blood pressure and declines in cardiac function. ANG-(1-7) infusion restores obesity-induced cardiac dysfunction of wild

  11. 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. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. 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.

  13. 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.

  14. 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.

  15. Receptor MAS protects mice against hypothermia and mortality induced by endotoxemia.

    PubMed

    Souza, Laura L; Duchene, Johan; Todiras, Mihail; Azevedo, Luciano C P; Costa-Neto, Claudio M; Alenina, Natalia; Santos, Robson A; Bader, Michael

    2014-04-01

    The renin-angiotensin (Ang) system is involved in maintaining cardiovascular function by regulating blood pressure and electrolyte homeostasis. More recently, alternative pathways within the renin-angiotensin system have been described, such as the ACE-2/Ang-(1-7)/Mas axis, with opposite effects to the ones of the ACE/Ang-II/AT1 axis. Correspondingly, our previous work reported that Ang-(1-7) via its receptor Mas inhibits the mRNA expression of the proinflammatory cytokines interleukin 6 (IL-6) and tumor necrosis factor-α increased by lipopolysaccharide (LPS) in mouse peritoneal macrophages. These data led us to investigate the functional role of the Ang-(1-7)/Mas axis in an in vivo LPS model. In this work, we present evidence that Ang-(1-7) via Mas significantly reduced the LPS-increased production of circulating cytokines, such as IL-6, IL-12, and CXCL-1. This inhibitory effect was mediated by Mas because it was not detectable in Mas-deficient (Mas) mice. Accordingly, IL-6, CXCL-1, and CXCL-2 levels were higher after LPS treatment in the absence of Mas. Mas mice were less resistant to LPS-induced endotoxemia, their survival rate being 50% compared with 95% in wild-type mice. Telemetric analyses showed that Mas mice presented more pronounced LPS-induced hypothermia with a 3°C lower body temperature compared with wild-type mice. Altogether, our findings suggest that Ang-(1-7) and Mas inhibit LPS-induced cytokine production and hypothermia and thereby protect mice from the fatal consequences of endotoxemia.

  16. Mas receptor deficiency exacerbates lipopolysaccharide-induced cerebral and systemic inflammation in mice.

    PubMed

    Oliveira-Lima, Onésia C; Pinto, Mauro C X; Duchene, Johan; Qadri, Fatimunnisa; Souza, Laura L; Alenina, Natalia; Bader, Michael; Santos, Robson A S; Carvalho-Tavares, Juliana

    2015-12-01

    Beyond the classical actions of the renin-angiotensin system on the regulation of cardiovascular homeostasis, several studies have shown its involvement in acute and chronic inflammation. The G protein-coupled receptor Mas is a functional binding site for the angiotensin-(1-7); however, its role in the immune system has not been fully elucidated. In this study, we evaluated the effect of genetic deletion of Mas receptor in lipopolysaccharide (LPS)-induced systemic and cerebral inflammation in mice. Inflammatory response was triggered in Mas deficient (Mas(-/-)) and C57BL/6 wild-type (WT) mice (8-12 weeks-old) by intraperitoneal injection of LPS (5 mg/kg). Mas(-/-) mice presented more intense hypothermia compared to WT mice 24 h after LPS injection. Systemically, the bone marrow of Mas(-/-) mice contained a lower number of neutrophils and monocytes 3 h and 24 h after LPS injection, respectively. The plasma levels of inflammatory mediators KC, MCP-1 and IL-10 were higher in Mas(-/-) mice 24 h after LPS injection in comparison to WT. In the brain, Mas(-/-) animals had a significant increase in the number of adherent leukocytes to the brain microvasculature compared to WT mice, as well as, increased number of monocytes and neutrophils recruited to the pia-mater. The elevated number of adherent leukocytes on brain microvasculature in Mas(-/-) mice was associated with increased expression of CD11b - the alpha-subunit of the Mac-1 integrin - in bone marrow neutrophils 3h after LPS injection, and with increased brain levels of chemoattractants KC, MIP-2 and MCP-1, 24 h later. In conclusion, we demonstrated that Mas receptor deficiency results in exacerbated inflammation in LPS-challenged mice, which suggest a potential role for the Mas receptor as a regulator of systemic and brain inflammatory response induced by LPS. Copyright © 2015 Elsevier GmbH. All rights reserved.

  17. Impact of crosslinking/riboflavin-UVA-photodynamic inactivation on viability, apoptosis and activation of human keratocytes in vitro

    PubMed Central

    Stachon, Tanja; Wang, Jiong; Song, Xufei; Langenbucher, Achim; Seitz, Berthold; Szentmáry, Nóra

    2015-01-01

    Abstract Riboflavin-UVA photodynamic inactivation is a potential treatment alternative in therapy resistant infectious keratitis. The purpose of our study was to determine the impact of riboflavin-UVA photodynamic inactivation on viability, apoptosis and activation of human keratocytes in vitro. Primary human keratocytes were isolated from human corneal buttons and cultured in DMEM/Ham's F12 medium supplemented with 10% fetal calf serum. Keratocytes underwent UVA light illumination (375 nm) for 4.10 minutes (2 J/cm2) during exposure to different concentrations of riboflavin. Twenty-four hours after treatment, cell viability was evaluated photometrically, whereas apoptosis, CD34 and alpha-smooth muscle actin (α-SMA) expression were assessed using flow cytometry. We did not detect significant changes in cell viability, apoptosis, CD34 and α-SMA expression in groups only treated with riboflavin or UVA light. In the group treated with riboflavin-UVA-photodynamic inactivation, viability of keratocytes decreased significantly at 0.1% riboflavin (P<0.01) while the percentage of CD34 (P<0.01 for both 0.05% and 0.1% riboflavin) and alpha-SMA positive keratocytes (P<0.01 and P<0.05 for 0.05% and 0.1% riboflavin, respectively) increased significantly compared to the controls. There was no significant change in the percentage of apoptotic keratocytes compared to controls at any of the used riboflavin concentrations (P = 0.09 and P = 0.13). We concluded that riboflavin-UVA-photodynamic-inactivation decreases viability of myofibroblastic transformation and multipotent haematopoietic stem cell transformation; however, it does not have an impact on apoptosis of human keratocytes in vitro. PMID:26243519

  18. 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.

  19. 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.

  20. 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

  1. 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.

  2. 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.

  3. 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.

  4. 47 CFR 101.1317 - Competitive bidding procedures for mutually exclusive MAS EA applications.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Competitive bidding procedures for mutually exclusive MAS EA applications. 101.1317 Section 101.1317 Telecommunication FEDERAL COMMUNICATIONS COMMISSION... License Requirements § 101.1317 Competitive bidding procedures for mutually exclusive MAS EA...

  5. Role of the receptor Mas in macrophage-mediated inflammation in vivo.

    PubMed

    Hammer, Anna; Yang, Guang; Friedrich, Juliane; Kovacs, Agnes; Lee, De-Hyung; Grave, Katharina; Jörg, Stefanie; Alenina, Natalia; Grosch, Janina; Winkler, Jürgen; Gold, Ralf; Bader, Michael; Manzel, Arndt; Rump, Lars C; Müller, Dominik N; Linker, Ralf A; Stegbauer, Johannes

    2016-12-06

    Recently, an alternative renin-angiotensin system pathway has been described, which involves binding of angiotensin-(1-7) to its receptor Mas. The Mas axis may counterbalance angiotensin-II-mediated proinflammatory effects, likely by affecting macrophage function. Here we investigate the role of Mas in murine models of autoimmune neuroinflammation and atherosclerosis, which both involve macrophage-driven pathomechanisms. Mas signaling affected macrophage polarization, migration, and macrophage-mediated T-cell activation. Mas deficiency exacerbated the course of experimental autoimmune encephalomyelitis and increased macrophage infiltration as well as proinflammatory gene expression in the spleen and spinal cord. Furthermore, Mas deficiency promoted atherosclerosis by affecting macrophage infiltration and migration and led to increased oxidative stress as well as impaired endothelial function in ApoE-deficient mice. In summary, we identified the Mas axis as an important factor in macrophage function during inflammation of the central nervous and vascular system in vivo. Modulating the Mas axis may constitute an interesting therapeutic target in multiple sclerosis and/or atherosclerosis.

  6. Hydronephrosis alters cardiac ACE2 and Mas receptor expression in mice.

    PubMed

    Zhang, Yanling; Ma, Lulu; Wu, Junyan; Chen, Tingting

    2015-06-01

    Hydronephrosis is characterized by substantial loss of tubules and affects renin secretion in the kidney. However, whether alterations of angiotensin-converting enzyme (ACE), ACE2 and Mas receptor in the heart are observed in hydronephrosis is unknown. Thus, we assessed these components in hydronephrotic mice treated with AT1 receptor blockade and ACE inhibitor. Hydronephrosis was induced by left ureteral ligation in Balb/C mice except sham-operated animals. The levels of cardiac ACE, ACE2 and Mas receptor were measured after treatment of losartan or enalapril. Hydronephrosis led to an increase of ACE level and a decrease of ACE2 and Mas receptor in the heart. Losartan decreased cardiac ACE level, but ACE2 and Mas receptor levels significantly increased in hydronephrotic mice (p < 0.01). Enalapril increased ACE2 levels (p < 0.01), but did not affect Mas receptor in the heart. Plasma renin activity (PRA) and Ang II decreased in hydronephrotic mice, but significantly increased after treatment with losartan or enalapril. Hydronephrosis increased cardiac ACE and suppressed ACE2 and Mas receptor levels. AT1 blockade caused sustained activation of cardiac ACE2 and Mas receptor, but ACE inhibitor had the limitation of such activation of Mas receptor in hydronephrotic animals. © The Author(s) 2015.

  7. Psychometric Comparison of the Motivation Assessment Scale (MAS) and the Questions about Behavioral Function (QABF)

    ERIC Educational Resources Information Center

    Koritsas, S.; Iacono, T.

    2013-01-01

    Background: The Motivation Assessment Scale (MAS) and the Questions About Behavioral Function (QABF) are frequently used to assess the learned function of challenging behaviour in people with intellectual disability (ID). The aim was to explore and compare the psychometric properties of the MAS and the QABF. Method: Seventy adults with ID and…

  8. Role of the receptor Mas in macrophage-mediated inflammation in vivo

    PubMed Central

    Hammer, Anna; Yang, Guang; Friedrich, Juliane; Kovacs, Agnes; Lee, De-Hyung; Grave, Katharina; Jörg, Stefanie; Alenina, Natalia; Grosch, Janina; Winkler, Jürgen; Gold, Ralf; Bader, Michael; Manzel, Arndt; Rump, Lars C.; Müller, Dominik N.; Linker, Ralf A.; Stegbauer, Johannes

    2016-01-01

    Recently, an alternative renin–angiotensin system pathway has been described, which involves binding of angiotensin-(1–7) to its receptor Mas. The Mas axis may counterbalance angiotensin-II–mediated proinflammatory effects, likely by affecting macrophage function. Here we investigate the role of Mas in murine models of autoimmune neuroinflammation and atherosclerosis, which both involve macrophage-driven pathomechanisms. Mas signaling affected macrophage polarization, migration, and macrophage-mediated T-cell activation. Mas deficiency exacerbated the course of experimental autoimmune encephalomyelitis and increased macrophage infiltration as well as proinflammatory gene expression in the spleen and spinal cord. Furthermore, Mas deficiency promoted atherosclerosis by affecting macrophage infiltration and migration and led to increased oxidative stress as well as impaired endothelial function in ApoE-deficient mice. In summary, we identified the Mas axis as an important factor in macrophage function during inflammation of the central nervous and vascular system in vivo. Modulating the Mas axis may constitute an interesting therapeutic target in multiple sclerosis and/or atherosclerosis. PMID:27872279

  9. Genomic mapping and candidate genes as approaches to MAS of VSH

    USDA-ARS?s Scientific Manuscript database

    Introduction: Identification of genes and proteins associated with traits of interest allows for identification of molecular or biochemical markers which can be used to screen parents for desirable alleles and used in marker-assisted selection (MAS). Employing MAS for improvement or maintenance of r...

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. UVA, UVB Light Doses and Harvesting Time Differentially Tailor Glucosinolate and Phenolic Profiles in Broccoli Sprouts.

    PubMed

    Moreira-Rodríguez, Melissa; Nair, Vimal; Benavides, Jorge; Cisneros-Zevallos, Luis; Jacobo-Velázquez, Daniel A

    2017-06-26

    Broccoli sprouts contain health-promoting glucosinolate and phenolic compounds that can be enhanced by applying ultraviolet light (UV). Here, the effect of UVA or UVB radiation on glucosinolate and phenolic profiles was assessed in broccoli sprouts. Sprouts were exposed for 120 min to low intensity and high intensity UVA (UVAL, UVAH) or UVB (UVBL, UVBH) with UV intensity values of 3.16, 4.05, 2.28 and 3.34 W/m², respectively. Harvest occurred 2 or 24 h post-treatment; and methanol/water or ethanol/water (70%, v/v) extracts were prepared. Seven glucosinolates and 22 phenolics were identified. Ethanol extracts showed higher levels of certain glucosinolates such as glucoraphanin, whereas methanol extracts showed slight higher levels of phenolics. The highest glucosinolate accumulation occurred 24 h after UVBH treatment, increasing 4-methoxy-glucobrassicin, glucobrassicin and glucoraphanin by ~170, 78 and 73%, respectively. Furthermore, UVAL radiation and harvest 2 h afterwards accumulated gallic acid hexoside I (~14%), 4-O-caffeoylquinic acid (~42%), gallic acid derivative (~48%) and 1-sinapoyl-2,2-diferulolyl-gentiobiose (~61%). Increases in sinapoyl malate (~12%), gallotannic acid (~48%) and 5-sinapoyl-quinic acid (~121%) were observed with UVBH Results indicate that UV-irradiated broccoli sprouts could be exploited as a functional food for fresh consumption or as a source of bioactive phytochemicals with potential industrial applications.

  20. A generic, computerized nuclear materials accountability system (NucMAS) and its layered products

    SciTech Connect

    Davis, Jr, J M

    1989-01-01

    NucMAS provides a material balance area with a computerized data management system for nuclear materials accountability. NucMAS is a generic application. It handles the data management and reporting functions for different processing facilities by storing all process-specific information as data rather than procedure. A NucMAS application is configured for each facility it supports. NucMAS and its layered products are compatible with three types of data clients. Core NucMAS has a screen-oriented user interface to support the accountability clerk as a client. Accountability clerks enter data from operating logs and laboratory analyses one to three days after actual processing. Layered products support process operators and automated systems as near-real-time and real-time data clients. The core and layered products use a data-driven approach which results in software that is configurable and maintainable. 3 refs., 5 figs.

  1. UVA radiation is highly mutagenic in cells that are unable to repair 7,8-dihydro-8-oxoguanine in Saccharomyces cerevisiae.

    PubMed

    Kozmin, S; Slezak, G; Reynaud-Angelin, A; Elie, C; de Rycke, Y; Boiteux, S; Sage, E

    2005-09-20

    UVA (320-400 nm) radiation constitutes >90% of the environmentally relevant solar UV radiation, and it has been proposed to have a role in skin cancer and aging. Because of the popularity of UVA tanning beds and prolonged periods of sunbathing, the potential deleterious effect of UVA has emerged as a source of concern for public health. Although generally accepted, the impact of DNA damage on the cytotoxic, mutagenic, and carcinogenic effect of UVA radiation remains unclear. In the present study, we investigated the sensitivity of a panel of yeast mutants affected in the processing of DNA damage to the lethal and mutagenic effect of UVA radiation. The data show that none of the major DNA repair pathways, such as base excision repair, nucleotide excision repair, homologous recombination, and postreplication repair, efficiently protect yeast from the lethal action of UVA radiation. In contrast, the results show that the Ogg1 DNA glycosylase efficiently prevents UVA-induced mutagenesis, suggesting the formation of oxidized guanine residues. Furthermore, sequence analysis of UVA-induced canavanine-resistant mutations reveals a bias in favor of GC-->TA events when compared with spontaneous or H(2)O(2)-, UVC-, and gamma-ray- induced canavanine-resistant mutations in the WT strain. Taken together, our data point out a major role of oxidative DNA damage, mostly 7,8-dihydro-8-oxoguanine, in the genotoxicity of UVA radiation in the yeast Saccharomyces cerevisiae. Therefore, the capacity of skin cells to repair 7,8-dihydro-8-oxoguanine may be a key parameter in the mutagenic and carcinogenic effect of UVA radiation in humans.

  2. Mas receptor contributes to pregnancy-induced cardiac remodeling.

    PubMed

    Carmos-Silva, Cintia; Almeida, Jônathas Fernandes Queiroz de; Macedo, Larissa Matuda; Melo, Marcos Barrouin B; Pedrino, Gustavo Rodrigues; Santos, Fernanda Fernanda Cristina Alcantara; Biancardi, Manoel Francisco; Santos, Robson Augusto Souza Dos Augusto Souza; Carvalho, Adryano Augustto; Mendes, Elizabeth Pereira; Colugnati, Diego Basile; Mazaro-Costa, Renata; Castro, Carlos Henrique de

    2016-09-13

    Previous studies have demonstrated a protective effect of the Ang-(1-7)/Mas receptor axis on pathological cardiac hypertrophy. Also, the involvement of Mas receptor in the exercise-induced cardiac hypertrophy has been suggested. However, the role of the Ang-(1-7)/Mas receptor on pregnancy-induced cardiac remodeling remains unknown. The objective of this study was to evaluate the participation of the Mas receptor in the development of the cardiac hypertrophy and fibrosis induced by gestation. Female Wistar rats were shared in 3 groups: control , pregnant , and pregnant treated with Mas receptor antagonist A-779 . Wild type (WT) and Mas-knockout mice (KO) were distributed in non-pregnant  and pregnant  groups. Systolic blood pressure (SBP) was measured by tail-cuff plethysmography. The medial part of the left ventricle (LV) was collected for histological analysis. Echocardiographic analysis was used to evaluate the cardiac function. SBP was not changed by pregnancy or A-779 treatment in the Wistar rats. Pharmacological blockade or genetic deletion of Mas receptor attenuates the pregnancy-induced myocyte hypertrophy. The treatment with A-779 or genetic deletion of the Mas receptor increased the collagen III deposition in LV from pregnant animals without changing the fibroblast proliferation. KO mice presented a lower ejection fraction, fraction shortening, stroke volume and higher end systolic volume compared to WT. Interestingly, the pregnancy restored these parameters. In conclusion, these data show that while Mas receptor blockade or deletion decreases physiological hypertrophy of pregnancy, it is associated with more extracellular matrix deposition. These alterations are associated with improvement of the cardiac function through Mas-independent mechanism. ©2016 The Author(s).

  3. MAS receptors mediate vasoprotective and atheroprotective effects of candesartan upon the recovery of vascular angiotensin-converting enzyme 2-angiotensin-(1-7)-MAS axis functionality.

    PubMed

    Pernomian, Larissa; do Prado, Alejandro F; Gomes, Mayara S; Pernomian, Laena; da Silva, Carlos H T P; Gerlach, Raquel F; de Oliveira, Ana M

    2015-10-05

    AT1 antagonists effectively prevent atherosclerosis since AT1 upregulation and angiotensin II-induced proinflammatory actions are critical to atherogenesis. Despite the classic mechanisms underlying the vasoprotective and atheroprotective actions of AT1 antagonists, the cross-talk between angiotensin-converting enzyme-angiotensin II-AT1 and angiotensin-converting enzyme 2-angiotensin-(1-7)-MAS axes suggests other mechanisms beyond AT1 blockage in such effects. For instance, angiotensin-converting enzyme 2 activity is inhibited by reactive oxygen species derived from AT1-mediated proinflammatory signaling. Since angiotensin-(1-7) promotes antiatherogenic effects, we hypothesized that the vasoprotective and atheroprotective effects of AT1 antagonists could result from their inhibitory effects on the AT1-mediated negative modulation of vascular angiotensin-converting enzyme 2-angiotensin-(1-7)-MAS axis functionality. Interestingly, our results showed that early atherosclerosis triggered in thoracic aorta from high cholesterol fed-Apolipoprotein E-deficient mice impairs angiotensin-converting enzyme 2-angiotensin-(1-7)-MAS axis functionality by a proinflammatory-redox AT1-mediated pathway. In such mechanism, AT1 activation leads to the aortic release of tumor necrosis factor-α, which stimulates NAD(P)H oxidase/Nox1-driven generation of superoxide and hydrogen peroxide. While hydrogen peroxide inhibits angiotensin-converting enzyme 2 activity, superoxide impairs MAS functionality. Candesartan treatment restored the functionality of angiotensin-converting enzyme 2-angiotensin-(1-7)-MAS axis by inhibiting the proinflammatory-redox AT1-mediated mechanism. Candesartan also promoted vasoprotective and atheroprotective effects that were mediated by MAS since A779 (MAS antagonist) co-treatment inhibited them. The role of MAS receptors as the final mediators of the vasoprotective and atheroprotective effects of candesartan was supported by the vascular actions of angiotensin

  4. Atypical Signaling and Functional Desensitization Response of MAS Receptor to Peptide Ligands

    PubMed Central

    Tirupula, Kalyan C.; Desnoyer, Russell; Speth, Robert C.; Karnik, Sadashiva S.

    2014-01-01

    MAS is a G protein-coupled receptor (GPCR) implicated in multiple physiological processes. Several physiological peptide ligands such as angiotensin-(1–7), angiotensin fragments and neuropeptide FF (NPFF) are reported to act on MAS. Studies of conventional G protein signaling and receptor desensitization upon stimulation of MAS with the peptide ligands are limited so far. Therefore, we systematically analyzed G protein signals activated by the peptide ligands. MAS-selective non-peptide ligands that were previously shown to activate G proteins were used as controls for comparison on a common cell based assay platform. Activation of MAS by the non-peptide agonist (1) increased intracellular calcium and D-myo-inositol-1-phosphate (IP1) levels which are indicative of the activation of classical Gαq-phospholipase C signaling pathways, (2) decreased Gαi mediated cAMP levels and (3) stimulated Gα12-dependent expression of luciferase reporter. In all these assays, MAS exhibited strong constitutive activity that was inhibited by the non-peptide inverse agonist. Further, in the calcium response assay, MAS was resistant to stimulation by a second dose of the non-peptide agonist after the first activation has waned suggesting functional desensitization. In contrast, activation of MAS by the peptide ligand NPFF initiated a rapid rise in intracellular calcium with very weak IP1 accumulation which is unlike classical Gαq-phospholipase C signaling pathway. NPFF only weakly stimulated MAS-mediated activation of Gα12 and Gαi signaling pathways. Furthermore, unlike non-peptide agonist-activated MAS, NPFF-activated MAS could be readily re-stimulated the second time by the agonists. Functional assays with key ligand binding MAS mutants suggest that NPFF and non-peptide ligands bind to overlapping regions. Angiotensin-(1–7) and other angiotensin fragments weakly potentiated an NPFF-like calcium response at non-physiological concentrations (≥100 µM). Overall, our data

  5. Atypical signaling and functional desensitization response of MAS receptor to peptide ligands.

    PubMed

    Tirupula, Kalyan C; Desnoyer, Russell; Speth, Robert C; Karnik, Sadashiva S

    2014-01-01

    MAS is a G protein-coupled receptor (GPCR) implicated in multiple physiological processes. Several physiological peptide ligands such as angiotensin-(1-7), angiotensin fragments and neuropeptide FF (NPFF) are reported to act on MAS. Studies of conventional G protein signaling and receptor desensitization upon stimulation of MAS with the peptide ligands are limited so far. Therefore, we systematically analyzed G protein signals activated by the peptide ligands. MAS-selective non-peptide ligands that were previously shown to activate G proteins were used as controls for comparison on a common cell based assay platform. Activation of MAS by the non-peptide agonist (1) increased intracellular calcium and D-myo-inositol-1-phosphate (IP1) levels which are indicative of the activation of classical Gαq-phospholipase C signaling pathways, (2) decreased Gαi mediated cAMP levels and (3) stimulated Gα12-dependent expression of luciferase reporter. In all these assays, MAS exhibited strong constitutive activity that was inhibited by the non-peptide inverse agonist. Further, in the calcium response assay, MAS was resistant to stimulation by a second dose of the non-peptide agonist after the first activation has waned suggesting functional desensitization. In contrast, activation of MAS by the peptide ligand NPFF initiated a rapid rise in intracellular calcium with very weak IP1 accumulation which is unlike classical Gαq-phospholipase C signaling pathway. NPFF only weakly stimulated MAS-mediated activation of Gα12 and Gαi signaling pathways. Furthermore, unlike non-peptide agonist-activated MAS, NPFF-activated MAS could be readily re-stimulated the second time by the agonists. Functional assays with key ligand binding MAS mutants suggest that NPFF and non-peptide ligands bind to overlapping regions. Angiotensin-(1-7) and other angiotensin fragments weakly potentiated an NPFF-like calcium response at non-physiological concentrations (≥100 µM). Overall, our data suggest

  6. Effect of Light Irradiation and Sex Hormones on Jurkat T Cells: 17β-Estradiol but Not Testosterone Enhances UVA-Induced Cytotoxicity in Jurkat Lymphocytes

    PubMed Central

    Cohly, Hari H.P.; Graham-Evans, Barbara; Ndebele, Kenneth; Jenkins, John K.; McMurray, Robert; Yan, Jian; Yu, Hongtao; Angel, Michael F

    2005-01-01

    In Eastern cultures, such as India, it is traditionally recommended that women but not men cover their heads while working in the scorching sun. The purpose of this pilot study was to determine whether there was any scientific basis for this cultural tradition. We examined the differential cytotoxic effects of ultraviolet A light (UVA) on an established T cell line treated with female and male sex hormones. CD4+ Jurkat T cells were plated in 96 well plates at 2 × 106 cells/ml and treated with 17β-estradiol (EST) or testosterone (TE). These cells were irradiated by UVA light with an irradiance of 170 J/cm2 for 15min at a distance of 6 cm from the surface of the 96-well plate. Controls included cells not treated with hormones or UVA. The effects of EST and TE were investigated between 1 and 20 ng/mL. Cytotoxicity by fluorescein-diacetate staining and COMET assay generating single strand DNA cleavage, tail length and tail moment measurements were examined. The effect of estrogen (5ng/mL) on apoptosis and its mediators was further studied using DNA laddering and western blotting for bcl-2 and p53. We found that EST alone, without UVA, enhanced Jurkat T cell survival. However, EST exhibited a dose-related cytotoxicity in the presence of UVA; up to 28% at 20 ng/ml. TE did not alter UVA-induced cytotoxicity. Since TE did not alter cell viability in the presence of UVA further damaging studies were not performed. COMET assay demonstrated the harmful effects of EST in the presence of UVA while EST without UVA had no significant effect on the nuclear damage. Apoptosis was not present as indicated by the absence of DNA laddering on agarose gel electrophoresis at 5ng/ml EST or TE ± UVA. Western blot showed that estrogen down regulated bcl-2 independently of UVA radiation while p53 was down regulated in the presence of UVA treatment. EST and TE have differential effects on UVA-induced cytotoxicity in Jurkat T-lymphocyte which suggested that women may be more susceptible to

  7. 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.

  8. Ultrasensitive and Highly Selective Photodetections of UV-A Rays Based on Individual Bicrystalline GaN Nanowire.

    PubMed

    Zhang, Xinglai; Liu, Baodan; Liu, Qingyun; Yang, Wenjin; Xiong, Changmin; Li, Jing; Jiang, Xin

    2017-01-25

    The detection of UV-A rays (wavelength of 320-400 nm) using functional semiconductor nanostructures is of great importance in either fundamental research or technological applications. In this work, we report the catalytic synthesis of peculiar bicrystalline GaN nanowires and their utilization for building high-performance optoelectronic nanodevices. The as-prepared UV-A photodetector based on individual bicrystalline GaN nanowire demonstrates a fast photoresponse time (144 ms), a high wavelength selectivity (UV-A light response only), an ultrahigh photoresponsivity of 1.74 × 10(7) A/W and EQE of 6.08 × 10(9)%, a sensitivity of 2 × 10(4)%, and a very large on/off ratio of more than two orders, as well as robust photocurrent stability (photocurrent fluctuation of less than 7% among 4000 s), showing predominant advantages in comparison with other peer semiconductor photodetectors. The outstanding optoelectronic performance of the bicrystalline GaN nanowire UV-A photodetector is further analyzed based on a detailed high-resolution transmission electron microscope (HRTEM) study, and the two separated crystal domains within the GaN nanowires are believed to provide separated and rapid carrier transfer channels. This work paves a solid way toward the integration of high-performance optoelectronic nanodevices based on bicrystalline or horizontally aligned one-dimensional semiconductor nanostructures.

  9. 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…

  10. 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.

  11. 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…

  12. Specific Growth Rate Determines the Sensitivity of Escherichia coli to Thermal, UVA, and Solar Disinfection

    PubMed Central

    Berney, Michael; Weilenmann, Hans-Ulrich; Ihssen, Julian; Bassin, Claudio; Egli, Thomas

    2006-01-01

    Knowledge about the sensitivity of the test organism is essential for the evaluation of any disinfection method. In this work we show that sensitivity of Escherichia coli MG1655 to three physical stresses (mild heat, UVA light, and sunlight) that are relevant in the disinfection of drinking water with solar radiation is determined by the specific growth rate of the culture. Batch- and chemostat-cultivated cells from cultures with similar specific growth rates showed similar stress sensitivities. Generally, fast-growing cells were more sensitive to the stresses than slow-growing cells. For example, slow-growing chemostat-cultivated cells (D = 0.08 h−1) and stationary-phase bacteria from batch culture that were exposed to mild heat had very similar T90 (time until 90% of the population is inactivated) values (T90, chemostat = 2.66 h; T90, batch = 2.62 h), whereas T90 for cells growing at a μ of 0.9 h−1 was 0.2 h. We present evidence that the stress sensitivity of E. coli is correlated with the intracellular level of the alternative sigma factor RpoS. This is also supported by the fact that E. coli rpoS mutant cells were more stress sensitive than the parent strain by factors of 4.9 (mild heat), 5.3 (UVA light), and 4.1 (sunlight). Furthermore, modeling of inactivation curves with GInaFiT revealed that the shape of inactivation curves changed depending on the specific growth rate. Inactivation curves of cells from fast-growing cultures (μ = 1.0 h−1) that were irradiated with UVA light showed a tailing effect, while for slow-growing cultures (μ = 0.3 h−1), inactivation curves with shoulders were obtained. Our findings emphasize the need for accurate reporting of specific growth rates and detailed culture conditions in disinfection studies to allow comparison of data from different studies and laboratories and sound interpretation of the data obtained. PMID:16597961

  13. Wound healing in the rabbit cornea after corneal collagen cross-linking with riboflavin and UVA.

    PubMed

    Wollensak, Gregor; Iomdina, Elena; Dittert, Dag-Daniel; Herbst, Hermann

    2007-06-01

    This study was undertaken to investigate the wound healing process of the first 6 weeks after photodynamic cross-linking treatment in the rabbit cornea, using the photosensitizer riboflavin and UVA. After removal of the central epithelium, the right corneas of 8 Chinchilla rabbits were cross-linked with a photosensitizing 0.1% riboflavin solution and UVA light (370 nm; irradiance, 3 mW/cm(2); dose, 5.4 J/cm(2)) for 30 minutes. Two animals were euthanized 3 days, 7 days, 4 weeks, and 6 weeks postoperatively. The corneas of the enucleated eyes were evaluated using 4-microm light microscopic sections with routine stains and avidin-biotin complex immunostaining with anti-alpha-smooth muscle actin. By day 3 after treatment, complete apoptotic damage and loss of the endothelial cells and the stromal keratocytes were found in the irradiated area through the entire thickness of the stroma. There was marked stromal edema (850 +/- 66 vs. 332 +/- 43 microm in the untreated controls; P < 0.01). The epithelium was already closed again. At the margins of the lesion, there was a mild inflammatory reaction with scattered macrophages, lymphocytes, and neutrophils. By day 7, the endothelium was already intact again, and keratocyte repopulation of the posterior stroma was noted. By week 4, the keratocyte repopulation of the anterior stroma was observed with some acellular areas between. By week 6, the cytoarchitecture of the cornea seemed normal again. By weeks 4 and 6, alpha-actin-positive keratocytes were identified, especially in the periphery of the irradiated area. After riboflavin/UVA cross-linking of rabbit cornea, a complete cell loss occurs in the irradiation area with an irradiance of 3 mW/cm(2). The cytotoxic damage is repaired by repopulation after approximately 4-6 weeks. A combination of cross-linking with other procedures such as the implantation of intracorneal rings should be performed only after a sufficient time interval of approximately 2 months, allowing cellular

  14. Carbonylated proteins exposed to UVA and to blue light generate reactive oxygen species through a type I photosensitizing reaction.

    PubMed

    Mizutani, Taeko; Sumida, Hijiri; Sagawa, Yuki; Okano, Yuri; Masaki, Hitoshi

    2016-12-01

    Carbonylated proteins (CPs) are generated by the reaction of basic amino acid residues in proteins with aldehyde compounds produced during lipid peroxidation. CPs in the stratum corneum (SC) impact skin conditions such as skin moisture functions including water content and transepidermal water loss (TEWL). In addition, CPs can be frequently seen in the SC from sun-exposed sites compared with sun-protected sites. The aim of this study was to reveal whether CPs could be a generation source of reactive oxygen species (ROS) in the SC following exposure to ultraviolet (UV) radiation and to identify the type of ROS and its generation mechanism. ROS generation was detected using a methyl cypridina luciferin analog (MCLA) chemiluminescence system and an ESR spin-trapping method. CPs in porcine SC, in a keratin film and in bovine serum albumin (BSA) were prepared by reaction with acrolein. Levels of protein carbonylation were quantified by detecting aldehyde residues. CP levels in the SC were increased in a UVA energy-dependent manner. That result suggested that a source of ROS generation existed in the SC initiated and produced the carbonylation of SC proteins. Carbonylated BSA and carbonylated porcine SC sheets exhibited fluorescence spectra at an excitation wavelength of 430nm and an emission wavelength of 520nm. Irradiation of the SC with UVA increased protein carbonylation and the amount of autofluorescence in the SC. ROS generation in the SC caused by UVA and by short-wavelength visible light (blue light, 400-470nm) was detected by the MCLA chemiluminescence system. Artificially carbonylated porcine SCs and keratin films had increases of chemiluminescence intensity after exposure to both light sources as well. The addition of superoxide dismutase to the MCLA system completely abolished the incremental chemiluminescence intensity after both UVA and blue light exposure of the SC. In addition, acrolein-treated BSA gave ESR signals like hydroxyl radicals (OH) converted

  15. Sealed rotors for in situ high temperature high pressure MAS NMR

    SciTech Connect

    Hu, Jian Z.; Hu, Mary Y.; Zhao, Zhenchao; Xu, Souchang; Vjunov, Aleksei; Shi, Hui; Camaioni, Donald M.; Peden, Charles H. F.; Lercher, Johannes A.

    2015-07-06

    Magic angle spinning (MAS) nuclear magnetic resonance (NMR) investigations on heterogeneous samples containing solids, semi-solids, liquid and gases or a mixture of them under non-conventional conditions of a combined high pressure and high temperature, or cold temperature suffer from the unavailability of a perfectly sealed rotor. Here, we report the design of reusable and perfectly-sealed all-zircornia MAS rotors. The rotors are easy to use and are suitable for operation temperatures from below 0 to 250 °C and pressures up to 100 bar. As an example of potential applications we performed in situ MAS NMR investigations of AlPO₄-5 molecular sieve crystallization, a kinetic study of the cyclohexanol dehydration reaction using 13C MAS NMR, and an investigation of the metabolomics of intact biological tissue at low temperature using 1H HR-MAS NMR spectroscopy. The in situ MAS NMR experiments performed using the reported rotors allowed reproduction of the results from traditional batch reactions, while offering more detailed quantitative information at the molecular level, as demonstrated for the molecular sieve synthesis and activation energy measurements for cyclohexanol dehydration. The perfectly sealed rotor also shows promising application for metabolomics studies using 1H HR-MAS NMR.

  16. Sealed rotors for in situ high temperature high pressure MAS NMR

    DOE PAGES

    Hu, Jian Z.; Hu, Mary Y.; Zhao, Zhenchao; ...

    2015-07-06

    Magic angle spinning (MAS) nuclear magnetic resonance (NMR) investigations on heterogeneous samples containing solids, semi-solids, liquid and gases or a mixture of them under non-conventional conditions of a combined high pressure and high temperature, or cold temperature suffer from the unavailability of a perfectly sealed rotor. Here, we report the design of reusable and perfectly-sealed all-zircornia MAS rotors. The rotors are easy to use and are suitable for operation temperatures from below 0 to 250 °C and pressures up to 100 bar. As an example of potential applications we performed in situ MAS NMR investigations of AlPO₄-5 molecular sieve crystallization,more » a kinetic study of the cyclohexanol dehydration reaction using 13C MAS NMR, and an investigation of the metabolomics of intact biological tissue at low temperature using 1H HR-MAS NMR spectroscopy. The in situ MAS NMR experiments performed using the reported rotors allowed reproduction of the results from traditional batch reactions, while offering more detailed quantitative information at the molecular level, as demonstrated for the molecular sieve synthesis and activation energy measurements for cyclohexanol dehydration. The perfectly sealed rotor also shows promising application for metabolomics studies using 1H HR-MAS NMR.« less

  17. Pattern of Mas expression in acute and post-acute stage of nerve injury in mice.

    PubMed

    Assis, Alex Dias; de Assis Araújo, Fernanda; Dos Santos, Robson Augusto Souza; Andrade, Silvia Passos; Zanon, Renata Graciele

    2017-09-01

    Angiotensin-(1-7) (Ang [1-7]) and its receptor Mas are involved in a number of physiological processes, including control of arterial pressure and modulation of nervous system actions. However, the involvement of the Ang-(1-7)/Mas axis in peripheral nerve injury has not been investigated. Using a model of sciatic nerve injury in mice, we demonstrated opposing changes in Mas receptor expression at days 2 and 14 post-injury. Mas receptor expression was more intense 2days after the nerve lesion, compared with the intensity of the intact nerve. At this time point, the sciatic nerve functional index was -20. At day 14 after the lesion, the intensity of the immunostaining labeling in longitudinal sections of the nerve was reduced (∼30%) and the functional index increased +36 (gait improvement). In the axotomized group treated with A779 (a Mas receptor antagonist), the functional recovery index decreased in relation to the untreated axotomized group. The Mas receptor inhibitor also altered the intensity of labeling of S-100, GAP43, and IBA-1 (morphological features compatible with delayed axon growth). This study demonstrated that Ang-(1-7)/Mas axis activity was differentially modulated in the acute and post-acute stages of nerve injury. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. MasABK proteins interact with proteins of the type IV pilin system to affect social motility of Myxococcus xanthus.

    PubMed

    Fremgen, Sarah; Williams, Amanda; Furusawa, Gou; Dziewanowska, Katarzyna; Settles, Matthew; Hartzell, Patricia

    2013-01-01

    Gliding motility is critical for normal development of spore-filled fruiting bodies in the soil bacterium Myxococcus xanthus. Mutations in mgl block motility and development but one mgl allele can be suppressed by a mutation in masK, the last gene in an operon adjacent to the mgl operon. Deletion of the entire 5.5 kb masABK operon crippled gliding and fruiting body development and decreased sporulation. Expression of pilAGHI, which encodes type IV pili (TFP) components essential for social (S) gliding, several cryptic pil genes, and a LuxR family protein were reduced significantly in the Δmas mutant while expression of the myxalamide operon was increased significantly. Localization and two-hybrid analysis suggest that the three Mas proteins form a membrane complex. MasA-PhoA fusions confirmed that MasA is an integral cytoplasmic membrane protein with a ≈100 amino acid periplasmic domain. Results from yeast two-hybrid assays showed that MasA interacts with the lipoprotein MasB and MasK, a protein kinase and that MasB and MasK interact with one another. Additionally, yeast two-hybrid analysis revealed a physical interaction between two gene products of the mas operon, MasA and MasB, and PilA. Deletion of mas may be accompanied by compensatory mutations since complementation of the Δmas social gliding and developmental defects required addition of both pilA and masABK.

  19. MasABK Proteins Interact with Proteins of the Type IV Pilin System to Affect Social Motility of Myxococcus xanthus

    PubMed Central

    Fremgen, Sarah; Williams, Amanda; Furusawa, Gou; Dziewanowska, Katarzyna; Settles, Matthew; Hartzell, Patricia

    2013-01-01

    Gliding motility is critical for normal development of spore-filled fruiting bodies in the soil bacterium Myxococcus xanthus. Mutations in mgl block motility and development but one mgl allele can be suppressed by a mutation in masK, the last gene in an operon adjacent to the mgl operon. Deletion of the entire 5.5 kb masABK operon crippled gliding and fruiting body development and decreased sporulation. Expression of pilAGHI, which encodes type IV pili (TFP) components essential for social (S) gliding, several cryptic pil genes, and a LuxR family protein were reduced significantly in the Δmas mutant while expression of the myxalamide operon was increased significantly. Localization and two-hybrid analysis suggest that the three Mas proteins form a membrane complex. MasA-PhoA fusions confirmed that MasA is an integral cytoplasmic membrane protein with a ≈100 amino acid periplasmic domain. Results from yeast two-hybrid assays showed that MasA interacts with the lipoprotein MasB and MasK, a protein kinase and that MasB and MasK interact with one another. Additionally, yeast two-hybrid analysis revealed a physical interaction between two gene products of the mas operon, MasA and MasB, and PilA. Deletion of mas may be accompanied by compensatory mutations since complementation of the Δmas social gliding and developmental defects required addition of both pilA and masABK. PMID:23342171

  20. Characterization of the UVA protection provided by avobenzone, zinc oxide, and titanium dioxide in broad-spectrum sunscreen products.

    PubMed

    Beasley, Donathan G; Meyer, Thomas A

    2010-12-01

    Solar UV radiation (UVR) is composed of UVB (290-320 nm) and UVA (320-400 nm) wavelengths. Only two sunscreen active ingredients approved in the US, avobenzone (butylmethoxydibenzoylmethane) and zinc oxide (ZnO), provide true broad-spectrum protection against UVA wavelengths >360 nm. Although effective against shorter UVR wavelengths <360 nm, titanium dioxide (TiO(2)) is also often believed to confer broad-spectrum protection and is substituted for ZnO or avobenzone. To sustain its absorption capacity within a sunscreen film during UVR exposure, avobenzone needs to be formulated into sunscreen products using sound formulation strategies. To characterize the efficacy of avobenzone, ZnO, and TiO(2) in terms of their abilities to provide broad UVA protection and to demonstrate the effectiveness of the different formulation strategies used today to maintain the efficacy of avobenzone even during prolonged exposures to UVR. UVA efficacy was assessed by measuring absorbance profiles in vitro using Vitro Skin® (IMS Inc., Orange, CT, USA) as an inert substrate and by determining UVA protection factors (PFA) on human skin. The impact of avobenzone loss on sun protection factor (SPF) and PFA values was evaluated by serially reducing avobenzone concentrations in an otherwise photostable product. The photostabilizing influence of specific formulation ingredients was monitored by measuring the extent to which they prevented UVR-induced degradation of avobenzone, whereas photostability of commercial sunscreen products was quantified by measuring the percentage change in absorbance within the UVB and UVA spectral regions following irradiation of thin product films on inert substrates. Model formulations containing 3% avobenzone or 5% ZnO provided superior attenuation of UVA wavelengths >360 nm compared with formulas containing 5% TiO(2). Additionally, sunscreen products of similar SPF containing avobenzone or ZnO exhibited significantly higher PFA values than those

  1. Increased aortic intimal proliferation due to MasR deletion in vitro

    PubMed Central

    Alsaadon, Hiba; Kruzliak, Peter; Smardencas, Arthur; Hayes, Alan; Bader, Michael; Angus, Peter; Herath, Chandana; Zulli, Anthony

    2015-01-01

    A growing body of evidence suggests that the vascular actions of Ang-(1-7) appear to involve increased production of nitric oxide (NO), an important vasodilator, through the activation of MasR, thus indicating the involvement of the MasR in preventing endothelial dysfunction. However, it is unknown whether the MasR could be involved in the progression of the next step in atherosclerosis, neo-intimal formation. To determine whether the deletion of the MasR is involved in the development of intimal thickening in an in vitro model. Mice [three background controls (C57Bl/6) and 3 MasR (−/−)] were killed and the aortas excised and cleaned of connective tissue and cut into 3 mm rings. Rings were placed in an organ culture medium for 5 weeks, embedded in paraffin, cut at 5 μm and stained with haematoxylin and eosin and Masson’s trichrome. In addition, aortic reactivity was measured in organ baths. After 5 weeks of culture, the intima:media ratio increased in the aortas from MasR (−/−) mice compared to the control group by 4.5-fold (P < 0.01). However, no significant difference in nuclei area count (cell proliferation) between the MasR (−/−) mice and control group was observed (0.87 ± 0.29% vs. 0.94 ± 0.18%, respectively, P = ns). Functional studies showed only a minor vasoconstrictive and full vasodilative response. This study shows that the deletion of the MasR causes marked increase in the aortic intima:media ratio, which is not due to generalized cellular proliferation. These results provide a functional role for the MasR in atherogenesis. PMID:25676544

  2. Increased aortic intimal proliferation due to MasR deletion in vitro.

    PubMed

    Alsaadon, Hiba; Kruzliak, Peter; Smardencas, Arthur; Hayes, Alan; Bader, Michael; Angus, Peter; Herath, Chandana; Zulli, Anthony

    2015-06-01

    A growing body of evidence suggests that the vascular actions of Ang-(1-7) appear to involve increased production of nitric oxide (NO), an important vasodilator, through the activation of MasR, thus indicating the involvement of the MasR in preventing endothelial dysfunction. However, it is unknown whether the MasR could be involved in the progression of the next step in atherosclerosis, neo-intimal formation. To determine whether the deletion of the MasR is involved in the development of intimal thickening in an in vitro model. Mice [three background controls (C57Bl/6) and 3 MasR (-/-)] were killed and the aortas excised and cleaned of connective tissue and cut into 3 mm rings. Rings were placed in an organ culture medium for 5 weeks, embedded in paraffin, cut at 5 μm and stained with haematoxylin and eosin and Masson's trichrome. In addition, aortic reactivity was measured in organ baths. After 5 weeks of culture, the intima:media ratio increased in the aortas from MasR (-/-) mice compared to the control group by 4.5-fold (P < 0.01). However, no significant difference in nuclei area count (cell proliferation) between the MasR (-/-) mice and control group was observed (0.87 ± 0.29% vs. 0.94 ± 0.18%, respectively, P = ns). Functional studies showed only a minor vasoconstrictive and full vasodilative response. This study shows that the deletion of the MasR causes marked increase in the aortic intima:media ratio, which is not due to generalized cellular proliferation. These results provide a functional role for the MasR in atherogenesis.

  3. Propofol up-regulates Mas receptor expression in dorsal root ganglion neurons.

    PubMed

    Cao, Lijun; Xun, Junmei; Jiang, Xinghua; Tan, Rong

    2013-08-01

    Mas is a functional binding site for angiotensin (Ang)-(1-7), a critical component of the renin-angiotensin system that is involved in processing nociceptive information. A recent study reported the localization of Mas in rat dorsal root ganglia (DRG) and demonstrated that Ang-(1-7) produced a dose-dependent peripheral antinociceptive effect in rats through the Mas receptor by an opioid-independent mechanism. In the present study, we for the first time examined the effect of propofol on Mas expression in cultured DRG neurons. We treated rat DRG neurons with propofol at different concentrations (0.1, 0.5, 1, 5 or 10 microM) for different length of time (0.5, 1, 2, 4 or 6 h) with or without transcription inhibitor actinomycin D or different kinase inhibitors. Propofol increased the Mas receptormRNA level in a statistically significant dose- and time-dependent manner within 4 h, which led to dose-dependent up-regulation of the Mas receptor protein level as well as Ang-(1-7) binding on the cell membrane. Actinomycin D (1 mg/ml) and p38 mitogen-activated protein kinase inhibitor PD169316 (25 microM) completely abolished the effect of propofol on Mas receptor expression in DRG neurons. In conclusion, we demonstrate that propofol markedly up-regulates Mas receptor expression at the transcription level in DRG neurons by a p38 MAPK-dependent mechanism. This study provides new insights into the mechanisms of action of propofol in peripheral antinociception, and suggests a new regulatory mechanism on the Ang-(1-7)/Mas axis in the peripheral nervous system.

  4. A novel MAs(III)-selective ArsR transcriptional repressor.

    PubMed

    Chen, Jian; Nadar, Venkadesh Sarkarai; Rosen, Barry P

    2017-09-01

    Microbial expression of genes for resistance to heavy metals and metalloids is usually transcriptionally regulated by the toxic ions themselves. Arsenic is a ubiquitous, naturally occurring toxic metalloid widely distributed in soil and groundwater. Microbes biotransform both arsenate (As(V)) and arsenite (As(III)) into more toxic methylated metabolites methylarsenite (MAs(III)) and dimethylarsenite (DMAs(III)). Environmental arsenic is sensed by members of the ArsR/SmtB family. The arsR gene is autoregulated and is typically part of an operon that contains other ars genes involved in arsenic detoxification. To date every identified ArsR is regulated by inorganic As(III). Here we described a novel ArsR from Shewanella putrefaciens selective for MAs(III). SpArsR orthologs control expression of two MAs(III) resistance genes, arsP that encodes the ArsP MAs(III) efflux permease, and arsH encoding the ArsH MAs(III) oxidase. SpArsR has two conserved cysteine residues, Cys101 and Cys102. Mutation of either resulted in loss of MAs(III) binding, indicating that they form an MAs(III) binding site. SpArsR can be converted into an As(III)-responsive repressor by introduction of an additional cysteine that allows for three-coordinate As(III) binding. Our results indicate that SpArsR evolved selectivity for MAs(III) over As(III) in order to control expression of genes for MAs(III) detoxification. © 2017 John Wiley & Sons Ltd.

  5. Chronic nerve injury-induced Mas receptor expression in dorsal root ganglion neurons alleviates neuropathic pain.

    PubMed

    Zhao, Yuanting; Qin, Yue; Liu, Tuanjiang; Hao, Dingjun

    2015-12-01

    Neuropathic pain, which is characterized by hyperalgesia, allodynia and spontaneous pain, is one of the most painful symptoms that can be experienced in the clinic. It often occurs as a result of injury to the peripheral nerves, dorsal root ganglion (DRG), spinal cord or brain. The renin-angiotensin system (RAS) plays an important role in nociception. As an essential component of the RAS, the angiotensin (Ang)-(1-7)/Mas axis may be involved in antinociception. The aim of the present study was to explore the expression pattern of Mas in DRG neurons following chronic nerve injury and examine the effects of Mas inhibition and activation on neuropathic pain in a chronic constriction injury (CCI) rat model. The results showed, that compared with the sham group, CCI caused a time-dependent induction of Mas expression at both the mRNA and the protein levels in DRG neurons. Consistent with the results, isolated DRG neurons showed a time-dependent increase in Ang-(1-7) binding on the cell membrane following the CCI surgery, but not the sham surgery. Compared with the sham control groups, CCI significantly decreased the paw withdrawal latency and threshold, and this was markedly improved and aggravated by intrathecal injection of the selective Mas agonist Ang-(1-7) and the selective Mas inhibitor D-Pro7-Ang-(1-7), respectively. In conclusion, this study has provided the first evidence, to the best of our knowledge, that the Mas expression in DRG neurons is time-dependently induced by chronic nerve injury and that the intrathecal activation and inhibition of Mas can improve and aggravate CCI-induced neuropathic pain, respectively. This study has provided novel insights into the pathophysiological process of neuropathic pain and suggests that the Ang-(1-7)/Mas axis could be an effective therapeutic target for neuropathic pain, warranting further study.

  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. 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.

  9. Topical pimecrolimus and tacrolimus do not accelerate photocarcinogenesis in hairless mice after UVA or simulated solar radiation.

    PubMed

    Lerche, Catharina M; Philipsen, Peter A; Poulsen, Thomas; Wulf, Hans Christian

    2009-03-01

    Pimecrolimus and tacrolimus are topical calcineurin inhibitors developed specifically for the treatment of atopic eczema. Experience with long-term use of topical calcineurin inhibitors is limited and the risk of rare but serious adverse events remains a concern. We have previously demonstrated the absence of carcinogenic effect of tacrolimus alone and in combination with simulated solar radiation (SSR) on hairless mice. The aim of this study is to determine whether pimecrolimus accelerates photocarcinogenesis in combination with SSR or pimecrolimus and tacrolimus accelerate photocarcinogenesis in combination with UVA. We used 11 groups of 25 hairless female C3.Cg/TifBomTac immunocompetent mice (n = 275). Pimecrolimus cream or tacrolimus ointment was applied on their dorsal skin three times weekly followed by SSR (2, 4, or 6 standard erythema doses, SED) or UVA (25 J/cm(2)) 3-4 h later. This was done up to 365 days in the SSR-treated groups and up to 500 days in the UVA-treated groups. Pimecrolimus did not accelerate the time for development of the first, second or third tumor in any of the groups. Median time to the first tumor was 240 days for the control-2SED group compared with pimecrolimus-2SED group (233 days), control-4SED group (156 days) compared with pimecrolimus-4SED group (163 days) and control-6SED group (162 days) compared with pimecrolimus-6SED group (170 days). Only one mouse in each of the three UVA groups developed a tumor. We conclude that pimecrolimus in combination with SSR and both pimecrolimus and tacrolimus in combination with UVA do not accelerate photocarcinogenesis in hairless mice.

  10. 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.

  11. HPTLC densitometric analysis of arbutin in bulk drug and methanolic extracts of Arctostaphylos uva-ursi.

    PubMed

    Alam, P; Alqasoumi, S I; Shakeel, F; Abdel-Kader, M S

    2011-10-01

    A high-performance thin layer chromatographic densitometric method for the analysis of arbutin was developed and validated in the present investigation. Arbutin was separated on aluminium-backed silica gel 60 F(254) plates with methanol : chloroform (3:7)% (v/v) as the mobile phase. This system was found to give a compact spot of arbutin at a retention factor (R(f)) value of 0.32 ± 0.02. The limit of detection and limit of quantification were found to be 35.42 and 106.26 ng/spot, respectively. The proposed method with a high degree of precision and accuracy was employed for the analysis of arbutin in the bulk drug and methanolic extract of Arctostaphylos uva-ursi.

  12. 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.

  13. 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

  14. UVA-UVB photoprotective activity of topical formulations containing Morinda citrifolia extract.

    PubMed

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

  15. Effects of topical petrolatum and salicylic acid upon skin photoreaction to UVA.

    PubMed

    Birgin, Bahar; Fetil, Emel; Ilknur, Turna; Tahsin Güneş, Ali; Ozkan, Sebnem

    2005-01-01

    Various agents which can be used in combination can also interfere with phototherapy. In this study, the effects of topical petrolatum and 20% salicylic acid in petrolatum upon skin photoreaction to UVA were investigated, in an in vivo test. Minimal phototoxic dose (MPD) test was performed on 31 volunteers and the test was repeated with thin (0.1 cc/25 cm(2)) petrolatum, thick (0.3 cc/25 cm(2)) petrolatum, thin 20% salicylic acid in petrolatum, thick 20% salicylic acid in petrolatum and sunscreen. The effect of each agent on MPD was investigated. MPD was increased with thin and thick applications of all agents. Also, MPD was increased with 20% salicylic acid in petrolatum when compared with pure petrolatum, in the same thickness. The application of petrolatum and salicylic acid in petrolatum just before PUVA therapy is not recommended because of their blocking effects.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. UVA photoirradiation of halogenated-polycyclic aromatic hydrocarbons leading to induction of lipid peroxidation.

    PubMed

    Herreno-Sáenz, Diógenes; Xia, Qingsu; Chiu, Li-Ting; Fu, Peter P

    2006-06-01

    Since the finding in the 1930s, a large number of polycyclic aromatic hydrocarbons (PAHs) of different structures have been tested for potential tumorigenicity. Structure-activity relationships of halo-PAHs have been investigated to determine the regions of a PAH that may be involved in cancer initiation. From these studies, a number of halo-PAHs were found to be tumorigenic in experimental animals. It was not until the 1980s that halo- PAHs were found to be present in the environment, including municipal incinerator fly ash, urban air, coal combustion, soil, snow, automobile exhausts, and tap water. Due to their widespread presence in the environment and their genotoxic activities, including carcinogenicity, many of these compounds may pose a health risk to humans. Although the biological activities, including metabolism, mutagenicity, and carcinogenicity, of halo- PAHs have been studied their phototoxicity and photo-induced biological activity have not been well examined. In this study, we study the photoirradiation of a series of structure-related halo-PAHs by UVA light in the presence of a lipid, methyl linoleate, and determine as to whether or not these compounds can induce lipid peroxidation. The halo-PAHs chosen for study include 2-bromonaphthalene, 1-chloroanthracene, 9,10- dibromoanthracene, 9-chlorophenanthrene, 9-bromophenanthrene, 7-chlorobenz[a]anthracene, 7- bromobenz[a]anthracene, 7-bromo-5-methylbenz[a]anthracene, 6-chlorobenzo[a]pyrene, and 6- bromobenzo[a]pyrene. The results indicate that upon photoirradiation by UVA all these compounds induced lipid peroxidation at different levels. These results suggest that halo-PAHs may be harmful to human health.

  1. UVA Photoirradiation of Halogenated-Polycyclic Aromatic Hydrocarbons Leading to Induction of Lipid Peroxidation

    PubMed Central

    Herreno-Sáenz, Diógenes; Xia, Qingsu; Chiu, Li-Ting; Fu, Peter P.

    2006-01-01

    Since the finding in the 1930s, a large number of polycyclic aromatic hydrocarbons (PAHs) of different structures have been tested for potential tumorigenicity. Structure-activity relationships of halo-PAHs have been investigated to determine the regions of a PAH that may be involved in cancer initiation. From these studies, a number of halo-PAHs were found to be tumorigenic in experimental animals. It was not until the 1980s that halo-PAHs were found to be present in the environment, including municipal incinerator fly ash, urban air, coal combustion, soil, snow, automobile exhausts, and tap water. Due to their widespread presence in the environment and their genotoxic activities, including carcinogenicity, many of these compounds may pose a health risk to humans. Although the biological activities, including metabolism, mutagenicity, and carcinogenicity, of halo-PAHs have been studied their phototoxicity and photo-induced biological activity have not been well examined. In this study, we study the photoirradiation of a series of structure-related halo-PAHs by UVA light in the presence of a lipid, methyl linoleate, and determine as to whether or not these compounds can induce lipid peroxidation. The halo-PAHs chosen for study include 2-bromonaphthalene, 1-chloroanthracene, 9,10-dibromoanthracene, 9-chlorophenanthrene, 9-bromophenanthrene, 7-chlorobenz[a]anthracene, 7-bromobenz[a]anthracene, 7-bromo-5-methylbenz[a]anthracene, 6-chlorobenzo[a]pyrene, and 6-bromobenzo[a]pyrene. The results indicate that upon photoirradiation by UVA all these compounds induced lipid peroxidation at different levels. These results suggest that halo-PAHs may be harmful to human health. PMID:16823092

  2. Addressing technical challenges associated with the FDA's proposed rules for the UVA in vitro testing procedure.

    PubMed

    Dueva-Koganov, Olga V; Rocafort, Colleen; Orofino, Steven; Osterwalder, Uli; Brito, Juan

    2009-01-01

    The proposed rules of the Food and Drug Administration (FDA) for the UVA in vitro testing procedure were applied to the evaluation of various sunscreen formulations and the following technical challenges were observed: when proposed roughened quartz substrates were used, the required coefficient-of-variation criteria were not met, and the dynamic ranges of the available transmittance analyzers were exceeded for sunscreens with high SPF values. In the proposed rules, the FDA requested comment regarding the suitability of other possible substrates. In this research, two modifications to the FDA's proposed rules were evaluated: (a) the use of an alternative substrate, Vitro Skin N-19 (IMS, Inc.) instead of roughened quartz substrate and (b) an increase in application time from 10 seconds to 30 seconds to ensure a uniform distribution of sunscreen product over the application area of the substrate. These two modifications allowed meeting the required coefficient-of-variation criteria without exceeding the dynamic ranges of the available transmittance analyzers. The modified test conditions were utilized for the evaluation of six commercial sunscreens, which fulfilled criteria of "medium" or "high" categories-based on their UVAI/UV ratios. These findings were in agreement with the statement in the proposed rules that the FDA is aware of the difficulty for current sunscreen formulations to meet the "highest" category and believes that allowing such a category will foster additional research and development in this area. To determine if it was possible to achieve a UVA rating greater than 0.95, two experimental sunscreen prototypes with bisoctrizole (USAN), bemotrizinol (USAN), avobenzone, and octocrylene were tested under the modified test conditions and attained the "highest" category. It should be noted that bisoctrizole and bemotrizinol are being evaluated by the FDA under TEA and are not permitted in the US at this time, but they are approved for use in the rest of

  3. 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

  4. 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.

  5. 77 FR 43084 - Multiple Award Schedule (MAS) Program Continuous Open Season-Operational Change

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-23

    ... needs of the government, especially under these current fiscal challenges. Operational efficiencies and cost control thus realized will restore and maintain the MAS program's value to Federal agencies as...

  6. BOREAS Level-2 MAS Surface Reflectance and Temperature Images in BSQ Format

    NASA Technical Reports Server (NTRS)

    Hall, Forrest G. (Editor); Newcomer, Jeffrey (Editor); Lobitz, Brad; Spanner, Michael; Strub, Richard; Lobitz, Brad

    2000-01-01

    The BOReal Ecosystem-Atmosphere Study (BOREAS) Staff Science Aircraft Data Acquisition Program focused on providing the research teams with the remotely sensed aircraft data products they needed to compare and spatially extend point results. The MODIS Airborne Simulator (MAS) images, along with other remotely sensed data, were collected to provide spatially extensive information over the primary study areas. This information includes biophysical parameter maps such as surface reflectance and temperature. Collection of the MAS images occurred over the study areas during the 1994 field campaigns. The level-2 MAS data cover the dates of 21-Jul-1994, 24-Jul-1994, 04-Aug-1994, and 08-Aug-1994. The data are not geographically/geometrically corrected; however, files of relative X and Y coordinates for each image pixel were derived by using the C130 navigation data in a MAS scan model. The data are provided in binary image format files.

  7. BOREAS Level-1B MAS Imagery At-sensor Radiance, Relative X and Y Coordinates

    NASA Technical Reports Server (NTRS)

    Strub, Richard; Strub, Richard; Newcomer, Jeffrey A.; Ungar, Stephen

    2000-01-01

    For BOReal Ecosystem-Atmosphere Study (BOREAS), the MODIS Airborne Simulator (MAS) images, along with the other remotely sensed data, were collected to provide spatially extensive information over the primary study areas. This information includes detailed land cover and biophysical parameter maps such as fraction of Photosynthetically Active Radiation (fPAR) and Leaf Area Index (LAI). Collection of the MAS images occurred over the study areas during the 1994 field campaigns. The level-1b MAS data cover the dates of 21-Jul-1994, 24-Jul-1994, 04-Aug-1994, and 08-Aug-1994. The data are not geographically/geometrically corrected; however, files of relative X and Y coordinates for each image pixel were derived by using the C-130 INS data in a MAS scan model. The data are provided in binary image format files.

  8. Cassini's Maneuver Automation Software (MAS) Process: How to Successfully Command 200 Navigation Maneuvers

    NASA Technical Reports Server (NTRS)

    Yang, Genevie Velarde; Mohr, David; Kirby, Charles E.

    2008-01-01

    To keep Cassini on its complex trajectory, more than 200 orbit trim maneuvers (OTMs) have been planned from July 2004 to July 2010. With only a few days between many of these OTMs, the operations process of planning and executing the necessary commands had to be automated. The resulting Maneuver Automation Software (MAS) process minimizes the workforce required for, and maximizes the efficiency of, the maneuver design and uplink activities. The MAS process is a well-organized and logically constructed interface between Cassini's Navigation (NAV), Spacecraft Operations (SCO), and Ground Software teams. Upon delivery of an orbit determination (OD) from NAV, the MAS process can generate a maneuver design and all related uplink and verification products within 30 minutes. To date, all 112 OTMs executed by the Cassini spacecraft have been successful. MAS was even used to successfully design and execute a maneuver while the spacecraft was in safe mode.

  9. Intercomparison of MAS, AVIRIS, and HIS data from FIRE cirrus 2

    NASA Technical Reports Server (NTRS)

    Gumley, Liam E.; King, Michael D.; Tsay, Si-Chee; Gao, Bo-Cai; Arnold, G. Thomas

    1993-01-01

    The NASA ER-2 flight on 5 Dec. 1991 is unique among the FIRE Cirrus 2 missions in that data were acquired simultaneously by the MODIS Airborne Simulator (MAS), the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS), and the High Resolution Interferometer Sounder (HIS). These data represent a unique source of information about the spatial and spectral properties of cirrus clouds. The MAS is a new instrument which will aid in defining algorithms and building an understanding of the ability of the Moderate Resolution Imaging Spectroradiometer (MODIS) to remotely sense atmospheric conditions for assessing global change. In order to establish confidence in the absolute calibration accuracy of the MAS radiances, an inter-comparison of MAS radiances with AVIRIS and HIS has been undertaken.

  10. Cassini's Maneuver Automation Software (MAS) Process: How to Successfully Command 200 Navigation Maneuvers

    NASA Technical Reports Server (NTRS)

    Yang, Genevie Velarde; Mohr, David; Kirby, Charles E.

    2008-01-01

    To keep Cassini on its complex trajectory, more than 200 orbit trim maneuvers (OTMs) have been planned from July 2004 to July 2010. With only a few days between many of these OTMs, the operations process of planning and executing the necessary commands had to be automated. The resulting Maneuver Automation Software (MAS) process minimizes the workforce required for, and maximizes the efficiency of, the maneuver design and uplink activities. The MAS process is a well-organized and logically constructed interface between Cassini's Navigation (NAV), Spacecraft Operations (SCO), and Ground Software teams. Upon delivery of an orbit determination (OD) from NAV, the MAS process can generate a maneuver design and all related uplink and verification products within 30 minutes. To date, all 112 OTMs executed by the Cassini spacecraft have been successful. MAS was even used to successfully design and execute a maneuver while the spacecraft was in safe mode.

  11. Expression and cellular localization of the Mas receptor in the adult and developing mouse retina.

    PubMed

    Prasad, Tuhina; Verma, Amrisha; Li, Qiuhong

    2014-01-01

    Recent studies have provided evidence that a local renin-angiotensin system (RAS) exists in the retina and plays an important role in retinal neurovascular function. We have recently shown that increased expression of ACE2 and angiotensin (1-7) [Ang (1-7)], two components of the protective axis of the RAS, in the retina via adeno-associated virus (AAV)-mediated gene delivery, conferred protection against diabetes-induced retinopathy. We hypothesized that the protective molecular and cellular mechanisms of Ang (1-7) are mediated by its receptor, Mas, and the expression level and cellular localization dictate the response to Ang (1-7) and activation of subsequent protective signaling pathways. We tested this hypothesis by examining the expression and cellular localization of the Mas receptor in adult and developing mouse retinas. The cellular localization of the Mas receptor protein was determined with immunofluorescence of the eyes of adult and postnatal day 1 (P1), P5, P7, P15, and P21 mice using the Mas receptor-specific antibody, and mRNA was detected with in situ hybridization of paraffin-embedded sections. Western blotting and real-time reverse-transcription (RT)-PCR analysis were performed to determine the relative levels of the Mas protein and mRNA in adult and developing retinas, as well as in cultured retinal Müller glial and RPE cells. In the adult eye, the Mas receptor protein was abundantly present in retinal ganglion cells (RGCs) and photoreceptor cells; a lower level of expression was observed in endothelial cells, Müller glial cells, and other neurons in the inner nuclear layer of the retina. In the developing retina, Mas receptor mRNA and protein expression was detected in the inner retina at P1, and the expression levels increased with age to reach the adult level and pattern by P15. In the adult mouse retina, Mas receptor mRNA was expressed at a much higher level when compared to angiotensin II (Ang II) type I (AT1R) and type II (AT2R) receptor m

  12. Angiotensin-(1-7)/Mas receptor as an antinociceptive agent in cancer-induced bone pain.

    PubMed

    Forte, Brittany L; Slosky, Lauren M; Zhang, Hong; Arnold, Moriah R; Staatz, William D; Hay, Meredith; Largent-Milnes, Tally M; Vanderah, Todd W

    2016-12-01

    Many cancerous solid tumors metastasize to the bone and induce pain (cancer-induced bone pain [CIBP]). Cancer-induced bone pain is often severe because of enhanced inflammation, rapid bone degradation, and disease progression. Opioids are prescribed to manage this pain, but they may enhance bone loss and increase tumor proliferation, further compromising patient quality of life. Angiotensin-(1-7) (Ang-(1-7)) binds and activates the Mas receptor (MasR). Angiotensin-(1-7)/MasR activation modulates inflammatory signaling after acute tissue insult, yet no studies have investigated whether Ang-(1-7)/MasR play a role in CIBP. We hypothesized that Ang-(1-7) inhibits CIBP by targeting MasR in a murine model of breast CIBP. 66.1 breast cancer cells were implanted into the femur of BALB/cAnNHsd mice as a model of CIBP. Spontaneous and evoked pain behaviors were assessed before and after acute and chronic administration of Ang-(1-7). Tissues were collected from animals for ex vivo analyses of MasR expression, tumor burden, and bone integrity. Cancer inoculation increased spontaneous pain behaviors by day 7 that were significantly reduced after a single injection of Ang-(1-7) and after sustained administration. Preadministration of A-779 a selective MasR antagonist prevented this reduction, whereas pretreatment with the AT2 antagonist had no effect; an AT1 antagonist enhanced the antinociceptive activity of Ang-(1-7) in CIBP. Repeated Ang-(1-7) administration did not significantly change tumor burden or bone remodeling. Data here suggest that Ang-(1-7)/MasR activation significantly attenuates CIBP, while lacking many side effects seen with opioids. Thus, Ang-(1-7) may be an alternative therapeutic strategy for the nearly 90% of patients with advanced-stage cancer who experience excruciating pain.

  13. U.S. Geological Survey mineral databases; MRDS and MAS/MILS

    USGS Publications Warehouse

    McFaul, E.J.; Mason, G.T.; Ferguson, W.B.; Lipin, B.R.

    2000-01-01

    These two CD-ROM's contain the latest version of the Mineral Resources Data System (MRDS) database and the Minerals Availability System/Minerals Industry Location System (MAS/MILS) database for coverage of North America and the world outside North America. The records in the MRDS database each contain almost 200 data fields describing metallic and nonmetallic mineral resources, deposits, and commodities. The records in the MAS/MILS database each contain almost 100 data fields describing mines and mineral processing plans.

  14. MAS Level-1B HDF Data and Derived Products during the CRYSTAL-FACE Field Campaign

    NASA Astrophysics Data System (ADS)

    Fitzgerald, M.; Dominguez, R.; Arnold, T.; Moody, E.

    2002-12-01

    During July 2002, the Cirrus Regional Study of Tropical Anvils and Cirrus Layers - Florida Area Cirrus Experiment (CRYSTAL-FACE) field campaign was conducted to study the radiative properties of tropical cirrus clouds. The field experiment was a cooperative effort of several government and university organizations, and involved coordination of 6 research aircraft and various ground-based instrumentation. During CRYSTAL-FACE, the MODIS Airborne Simulator (MAS), a 50-channel scanning radiometer was flown onboard the NASA ER-2 aircraft. The MAS was the only visible and infrared imaging instrument flown during the campaign. The purpose of this presentation is to demonstrate how collected raw MAS data is processed "in the field" to Level-1B HDF format and subsequent "science" products were then generated and used. MAS data was collected on all 13 ER-2 missions. All straight and level flight data were processed from raw data to level-1b (geo-located and calibrated to radiance at sensor) and written into a HDF file format. These preliminary data products were generated within 48-hours of data collection. In total 84 gigabytes of MAS data were processed to a Level-1B, HDF format. The MODIS science team generated several derived post processed and level-2 products, which utilized this MAS Level-1b HDF data. These field-derived products included a ecosystem map, several cloud phase determination models and brightness temperature. Later processing with this MAS HDF data product will be used for determination of cloud optical thickness and cloud particle radius. The MAS level-1b HDF data results will ultimately be compared with MODIS HDF data products for validation and comparison.

  15. Angiotensin-(1-7)/Mas receptor as an antinociceptive agent in cancer-induced bone pain

    PubMed Central

    Forte, Brittany L.; Slosky, Lauren M.; Zhang, Hong; Arnold, Moriah R.; Staatz, William D.; Hay, Meredith; Largent-Milnes, Tally M.; Vanderah, Todd W.

    2016-01-01

    Abstract Many cancerous solid tumors metastasize to the bone and induce pain (cancer-induced bone pain [CIBP]). Cancer-induced bone pain is often severe because of enhanced inflammation, rapid bone degradation, and disease progression. Opioids are prescribed to manage this pain, but they may enhance bone loss and increase tumor proliferation, further compromising patient quality of life. Angiotensin-(1-7) (Ang-(1-7)) binds and activates the Mas receptor (MasR). Angiotensin-(1-7)/MasR activation modulates inflammatory signaling after acute tissue insult, yet no studies have investigated whether Ang-(1-7)/MasR play a role in CIBP. We hypothesized that Ang-(1-7) inhibits CIBP by targeting MasR in a murine model of breast CIBP. 66.1 breast cancer cells were implanted into the femur of BALB/cAnNHsd mice as a model of CIBP. Spontaneous and evoked pain behaviors were assessed before and after acute and chronic administration of Ang-(1-7). Tissues were collected from animals for ex vivo analyses of MasR expression, tumor burden, and bone integrity. Cancer inoculation increased spontaneous pain behaviors by day 7 that were significantly reduced after a single injection of Ang-(1-7) and after sustained administration. Preadministration of A-779 a selective MasR antagonist prevented this reduction, whereas pretreatment with the AT2 antagonist had no effect; an AT1 antagonist enhanced the antinociceptive activity of Ang-(1-7) in CIBP. Repeated Ang-(1-7) administration did not significantly change tumor burden or bone remodeling. Data here suggest that Ang-(1-7)/MasR activation significantly attenuates CIBP, while lacking many side effects seen with opioids. Thus, Ang-(1-7) may be an alternative therapeutic strategy for the nearly 90% of patients with advanced-stage cancer who experience excruciating pain. PMID:27541850

  16. Ammonia Vapor Removal by Cu3(BTC)2 and Its Characterization by MAS NMR

    DTIC Science & Technology

    2009-01-01

    REPORT Ammonia Vapor Removal by Cu3(BTC)2 and Its Characterization by MAS NMR 14. ABSTRACT 16. SECURITY CLASSIFICATION OF: Adsorption equilibria and...NMR experiments were performed to study the adsorption and interactions of ammonia with metal-organic framework HKUST-1, or Cu3(BTC)2 (BTC ) 1,3,5... adsorption alone, suggesting a stronger interaction involving a potential reaction with the Cu3(BTC)2 framework. Indeed, 1H MAS NMR reveals that a major

  17. AVE 0991, a non-peptide Mas-receptor agonist, facilitates penile erection.

    PubMed

    da Costa Gonçalves, Andrey C; Fraga-Silva, Rodrigo A; Leite, Romulo; Santos, Robson A S

    2013-03-01

    The renin-angiotensin system plays a crucial role in erectile function. It has been shown that elevated levels of angiotensin II contribute to the development of erectile dysfunction both in humans and in aminals. On the contrary, the heptapeptide angiotensin-(1-7) appears to mediate penile erection by activation of the Mas receptor. Recently, we have shown that the erectile function of Mas gene-deleted mice was substantially reduced, which was associated with a marked increase in fibrous tissue in the corpus cavernosum. We have hypothesized that the synthetic non-peptide Mas agonist, AVE 0991, would potentiate penile erectile function. We showed that intracavernosal injection of AVE 0991 potentiated the erectile response of anaesthetized Wistar rats, measured as the ratio between corpus cavernosum pressure and mean arterial pressure, upon electrical stimulation of the major pelvic ganglion. The facilitatory effect of AVE 0991 on erectile function was dose dependent and completely blunted by the nitric oxide synthesis inhibitor, l-NAME. Importantly, concomitant intracavernosal infusion of the specific Mas receptor blocker, A-779, abolished the effect of AVE 0991. We demonstrated that AVE 0991 potentiates the penile erectile response through Mas in an NO-dependent manner. Importantly, these results suggest that Mas agonists, such as AVE 0991, might have significant therapeutic benefits for the treatment of erectile dysfunction.

  18. A novel α/β-hydrolase gene IbMas enhances salt tolerance in transgenic sweetpotato.

    PubMed

    Liu, Degao; Wang, Lianjun; Zhai, Hong; Song, Xuejin; He, Shaozhen; Liu, Qingchang

    2014-01-01

    Salt stress is one of the major environmental stresses in agriculture worldwide and affects crop productivity and quality. The development of crops with elevated levels of salt tolerance is therefore highly desirable. In the present study, a novel maspardin gene, named IbMas, was isolated from salt-tolerant sweetpotato (Ipomoea batatas (L.) Lam.) line ND98. IbMas contains maspardin domain and belongs to α/β-hydrolase superfamily. Expression of IbMas was up-regulated in sweetpotato under salt stress and ABA treatment. The IbMas-overexpressing sweetpotato (cv. Shangshu 19) plants exhibited significantly higher salt tolerance compared with the wild-type. Proline content was significantly increased, whereas malonaldehyde content was significantly decreased in the transgenic plants. The activities of superoxide dismutase (SOD) and photosynthesis were significantly enhanced in the transgenic plants. H2O2 was also found to be significantly less accumulated in the transgenic plants than in the wild-type. Overexpression of IbMas up-regulated the salt stress responsive genes, including pyrroline-5-carboxylate synthase, pyrroline-5-carboxylate reductase, SOD, psbA and phosphoribulokinase genes, under salt stress. These findings suggest that overexpression of IbMas enhances salt tolerance of the transgenic sweetpotato plants by regulating osmotic balance, protecting membrane integrity and photosynthesis and increasing reactive oxygen species scavenging capacity.

  19. A Novel α/β-Hydrolase Gene IbMas Enhances Salt Tolerance in Transgenic Sweetpotato

    PubMed Central

    Song, Xuejin; He, Shaozhen; Liu, Qingchang

    2014-01-01

    Salt stress is one of the major environmental stresses in agriculture worldwide and affects crop productivity and quality. The development of crops with elevated levels of salt tolerance is therefore highly desirable. In the present study, a novel maspardin gene, named IbMas, was isolated from salt-tolerant sweetpotato (Ipomoea batatas (L.) Lam.) line ND98. IbMas contains maspardin domain and belongs to α/β-hydrolase superfamily. Expression of IbMas was up-regulated in sweetpotato under salt stress and ABA treatment. The IbMas-overexpressing sweetpotato (cv. Shangshu 19) plants exhibited significantly higher salt tolerance compared with the wild-type. Proline content was significantly increased, whereas malonaldehyde content was significantly decreased in the transgenic plants. The activities of superoxide dismutase (SOD) and photosynthesis were significantly enhanced in the transgenic plants. H2O2 was also found to be significantly less accumulated in the transgenic plants than in the wild-type. Overexpression of IbMas up-regulated the salt stress responsive genes, including pyrroline-5-carboxylate synthase, pyrroline-5-carboxylate reductase, SOD, psbA and phosphoribulokinase genes, under salt stress. These findings suggest that overexpression of IbMas enhances salt tolerance of the transgenic sweetpotato plants by regulating osmotic balance, protecting membrane integrity and photosynthesis and increasing reactive oxygen species scavenging capacity. PMID:25501819

  20. Alteration of cardiac ACE2/Mas expression and cardiac remodelling in rats with aortic constriction.

    PubMed

    Zhang, Yanling; Li, Bing; Wang, Bingxiangi; Zhang, Jingjun; Wu, Junyan; Morgan, Trefor

    2014-12-31

    The recent discovery of the new components of the renin-angiotensin system (RAS) suggests the importance of the maintenance of cardiovascular structure and functions. To assess the role of the angiotensin-converting enzyme 2 (ACE2)-Mas receptor axis in the regulation of cardiac structure and function, the present work investigated the expression of ACE2 and Mas receptor in the heart in the cardiac remodeling that occurs in aortic constricted rats. Partial abdominal aortic ligation was carried out in Sprague-Dawley rats. Angiotensin AT1 receptor blockade and ACE inhibition were achieved by losartan and enalapril treatment, respectively. Results showed that aortic constriction increased left ventricular hypertrophy, fibrosis, mean arterial pressure (MAP), plasma renin activity (PRA) and cardiac ACE levels, but decreased the expression of cardiac ACE2 and Mas receptor. Losartan treatment significantly decreased MAP, left ventricle hypertrophy (LVH), fibrosis, and increased cardiac ACE2 and Mas expression. Enalapril also improved the cardiac parameters with a rise in cardiac ACE2, but did not change the Mas level. In conclusion, aortic constriction results in cardiac hypertrophy, fibrosis and a rise of cardiac ACE expression. Both AT1 receptor blocker and ACE inhibitor play a cardioprotective role in aortic constriction. However, AT1 receptor blocker particularly promotes cardiac ACE2 and Mas receptor levels. ACE inhibitor is associated with the inhibition of ACE and normalization of cardiac ACE2 activity.

  1. The expression of Mas-receptor of the renin-angiotensin system in the human eye.

    PubMed

    Vaajanen, A; Kalesnykas, G; Vapaatalo, H; Uusitalo, H

    2015-07-01

    The local renin-angiotensin system has been held to be expressed in many organs, including the eye. It has an important role in the regulation of local fluid homeostasis, cell proliferation, fibrosis, and vascular tone. Mas-receptor (Mas-R) is a potential receptor acting mainly opposite to the well-known angiotensin II receptor type 1. The aim of this study was to determine if Mas-R is expressed in the human eye. Seven enucleated human eyes were used in immunohistochemical detection of Mas-R and its endogenous ligand angiotensin (1-7) [Ang(1-7)]. Both light microscopy and immunofluorescent detection methods were used. A human kidney preparation sample was used as control. The Mas-R was found to have nuclear localization, and localized in the retinal nuclear layers and in the structures of the anterior segment of the eye. A cytoplasmic immunostaining pattern of Ang(1-7) was found in the inner and outer nuclear and plexiform layers of the retina and in the ciliary body. To the best of our knowledge, this is the first report showing Mas-R expression in the human eye. Its localization suggests that it may have a role in physiological and pathological processes in the anterior part of the eye and in the retina.

  2. Immunofluorescence localization of the receptor Mas in cardiovascular-related areas of the rat brain.

    PubMed

    Becker, Lenice K; Etelvino, Gisele M; Walther, Thomas; Santos, Robson A S; Campagnole-Santos, Maria J

    2007-09-01

    The G protein-coupled receptor Mas was recently described as an angiotensin-(1-7) [ANG-(1-7)] receptor. In the present study we evaluated the anatomical localization of Mas using immunofluorescence in the central nervous system of adult male Wistar rats. An abundant labeling was found in the hippocampus, amigdala, anterodorsal thalamic nucleus, cortex, and hypoglossal nucleus. More importantly, a dense ANG-(1-7) receptor Mas immunoreactivity was observed in cardiovascular-related areas of the medulla and forebrain, shown in several previous studies as sites for the action of ANG-(1-7) in the brain. A strong staining was found in the nucleus of the solitary tract, caudal and rostral ventrolateral medulla, inferior olive, parvo and magnocellular portions of the paraventricular hypothalamic nucleus, supraoptic nucleus, and lateral preoptic area. Furthermore, Mas staining was predominantly present in neurons. At the medullary sites, a specific and high-intensity binding for rhodamine-ANG-(1-7) was also shown. The specific ANG-(1-7) binding was completely displaced by the anti-Mas antibody or by the ANG-(1-7) antagonist, A-779. The data presented provide the first anatomical basis for the physiological role of ANG-(1-7)/Mas axis in the modulation of different cardiovascular functions and give new insights for clarifying the role of ANG-(1-7) in the central nervous system.

  3. Temperature calibration for high-temperature MAS NMR to 913 K: 63Cu MAS NMR of CuBr and CuI, and 23Na MAS NMR of NaNbO3.

    PubMed

    Wu, Jingshi; Kim, Namjun; Stebbins, Jonathan F

    2011-09-01

    The solid-state phase transitions of CuBr, CuI and NaNbO(3) can be readily observed using (63)Cu and (23)Na high-temperature magic-angle spinning nuclear magnetic resonance spectroscopy. Temperature has large, linear effects on the peak maximum of (63)Cu in each solid phase of CuBr and CuI, and there is large jump in shift across each phase transition. The (23)Na MAS NMR peak intensities and the line widths in NaNbO(3) also clearly show its high-temperature transition to the cubic phase. These data can be used to calibrate high-temperature MAS NMR probes up to 913 K, which is two hundred degrees higher than the commonly-used temperature calibration based on the chemical shift of (207)Pb in Pb(NO(3))(2). Copyright © 2011 Elsevier Inc. All rights reserved.

  4. 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.

  5. 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.

  6. Podocalyxin promotes glioblastoma multiforme cell invasion and proliferation by inhibiting angiotensin-(1-7)/Mas signaling.

    PubMed

    Liu, Bo; Liu, Yu; Jiang, Yugang

    2015-05-01

    Podocalyxin (PODX) reportedly enhances invasion in many human cancers including glioblastoma multiforme (GBM). Recent studies have shown that the local renin-angiotensin system (RAS) in tumor environment contributes significantly to tumor progression. As a counter-regulatory axis in RAS, angiotensin (Ang)-(1-7)/Mas signaling has been shown to inhibit the growth and invasiveness of several human cancers including GBM. In the present study, we examined the crosstalk between PODX and Ang-(1-7)/Mas signaling in GBM cells, and assessed its impact on GBM cell invasion and proliferation. A strong negative correlation between the expression of PODX and Mas in GBM tumor tissues from 10 consecutive patients (r=-0.768, p<0.01) was observed. The stable overexpression of PODX in LN-229 and U-118 MG human GBM cells decreased the expression of Mas at the mRNA and protein levels, which led to decreased density of Ang-(1-7)-binding Mas on the cell membrane. This effect was completely abolished by selective phosphatidylinositol 3-kinase (PI3K) inhibitor BKM120. By contrast, the stable knockdown of PODX in LN-229 and U-118 MG cells increased the expression of Mas and the density of Ang-(1-7)-binding Mas on the cell membrane. Overexpression and knockdown of PODX respectively reversed and enhanced the inhibitory effects of Ang-(1-7) on the expression/activity of matrix metalloproteinase-9 and cell invasion and proliferation in GBM cells. Although the overexpression of Mas showed no significant effect on the promoting effect of PODX on GBM cell invasion and proliferation in the absence of Ang-(1-7), it completely eliminated the effect of PODX in the presence of Ang-(1-7). In conclusion, to the best of our knowledge, the present study provided the first evidence that PODX inhibits Ang-(1-7)/Mas signaling by downregulating the expression of Mas through a PI3K-dependent mechanism in GBM cells. This effect led to enhanced GBM cell invasion and proliferation. The results of this study add

  7. 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.

  8. 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.

  9. 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.

  10. 2,6-Dimethyl-9-methoxy-4H-pyrrolo[3,2,1-ij]quinolin-4-one, a new compound with unusual photosensitizing properties.

    PubMed

    Baccichetti, F; Carlassare, F; Marzano, C; Guiotto, A; Rodighiero, P; Chilin, A; Bordin, F

    1994-07-01

    Some photobiological properties of 2,6-dimethyl-9-methoxy-4H-pyrrolo[3,2,1-ij]quinolin-4-one (PQ) have been studied in comparison with 8-methoxypsoralen (8-MOP). In Ehrlich cells, PQ induced a moderate inhibition in DNA and RNA syntheses in the dark, which appeared to be more pronounced upon UVA irradiation. In contrast to 8-MOP, in the presence of UVA, PQ also affected protein synthesis. Likewise marked antiproliferative effects were also observed in the study of the clonal growth of CHO cells cultivated in vitro. Using alkaline elution and CHO cells, a moderate formation of single-strand breaks (SSBs) and of DNA-protein cross-links (DPCs) was observed by incubation in the dark; upon UVA irradiation the amount of both lesions increased greatly, whereas no inter-strand cross-links (ISCs) were formed. As expected, 8-MOP did not damage DNA in the dark, but induced SSBs, ISCs and DPCs in the presence of UVA. The induction of SSBs by both compounds seems to be directly related to a photochemical event rather than to incisions during DNA repair. As the induction of ISCs, and also the formation of DPCs by 8-MOP and UVA, appears to be based on a two-step reaction involving photo-bound 8-MOP-DNA moieties. In contrast, the formation of DPCs by PQ and UVA seems to involve photosensitization by free PQ molecules connected with SSB and DPC formation rather than with a DNA photo-binding activity. The PQ activity observed in the dark could probably be ascribed to a moderate inhibition of topoisomerases.

  11. Mas receptor is involved in the estrogen-receptor induced nitric oxide-dependent vasorelaxation.

    PubMed

    Sobrino, Agua; Vallejo, Susana; Novella, Susana; Lázaro-Franco, Macarena; Mompeón, Ana; Bueno-Betí, Carlos; Walther, Thomas; Sánchez-Ferrer, Carlos; Peiró, Concepción; Hermenegildo, Carlos

    2017-04-01

    The Mas receptor is involved in the angiotensin (Ang)-(1-7) vasodilatory actions by increasing nitric oxide production (NO). We have previously demonstrated an increased production of Ang-(1-7) in human umbilical vein endothelial cells (HUVEC) exposed to estradiol (E2), suggesting a potential cross-talk between E2 and the Ang-(1-7)/Mas receptor axis. Here, we explored whether the vasoactive response and NO-related signalling exerted by E2 are influenced by Mas. HUVEC were exposed to 10nM E2 for 24h in the presence or absence of the selective Mas receptor antagonist A779, and the estrogen receptor (ER) antagonist ICI182780 (ICI). E2 increased Akt and endothelial nitric oxide synthase (eNOS) mRNA and protein expression, measured by RT-PCR and Western blot, respectively. Furthermore, E2 increased Akt activity (determined by the levels of phospho-Ser(473)) and eNOS activity (by the enhanced phosphorylation of Ser(1177), the activated form), resulting in increased NO production, which was measured by the fluorescence probe DAF-2-FM. These signalling events were dependent on ER and Mas receptor activation, since they were abolished in the presence of ICI or A779. In ex-vivo functional experiments performed with a small-vessel myograph in isolated mesenteric vessels from wild-type mice pre-contracted with noradrenaline, the relaxant response to physiological concentrations of E2 was blocked by ICI and A779, to the same extent to that obtained in the vessels isolated from Mas-deficient. In conclusion, E2 induces NO production and vasodilation through mechanisms that require Mas receptor activation.

  12. Mas receptor overexpression increased Ang-(1-7) relaxation response in renovascular hypertensive rat carotid.

    PubMed

    Olivon, V C; Aires, R D; Santiago, L B; Ramalho, L Z N; Cortes, S F; Lemos, V S

    2015-09-01

    Renin-angiotensin system (RAS) is an important factor in the pathophysiology of hypertension. Mas receptor, Angiotensin-(1-7) [Ang-(1-7)]-activated receptor, is an important RAS component and exerts protective effects in the vasculature. Ang-(1-7) vascular effects and Mas receptor expression in carotid from renovascular hypertensive (2K-1C) rats is not clear. In the present study we investigated Mas receptor vasodilator response activated by Ang-(1-7) in the carotid rings from sham and 2K-1C rats. Changes in isometric tension were recorded on organ chamber. Mas receptors expression was investigated in carotid by Western blot. Nitric oxide production was evaluated by 2,3-diaminonaphthalene (DAN) and eNOS expression and activity by immunofluoresce and western blot, respectively. Ang-(1-7) induced concentration-dependent vasodilator effect in carotid rings from sham and 2K-1C, which the hypertension increased vasodilatation response. In the 2K-1C carotid rings, A-779 (Mas receptor antagonist) reduced but not abolish the vasodilator effect of Ang-(1-7). Corroborating, Mas receptor protein expression was significantly increased in the 2K-1C rats. L-NAME and ibuprofen decreased Ang-(1-7) vasodilator response and L-NAME plus ibuprofen practically abolish the remaining vasodilatation response. Nitric oxide production is increased due increased of eNOS expression and pSer(1177) activity. Our results demonstrated that renovascular hypertension increased Mas receptors expression and nitric oxide production in the rats carotid which, consequently increased Ang-(1-7)-vasorelaxant response. Copyright © 2015 Elsevier Inc. All rights reserved.

  13. Photoirradiation of representative polycyclic aromatic hydrocarbons and twelve isomeric methylbenz[a]anthracene with UVA light: formation of lipid peroxidation.

    PubMed

    Xia, Qingsu; Chou, Ming W; Yin, Jun J; Howard, Paul C; Yu, Hongtao; Fu, Peter P

    2006-05-01

    Polycyclic aromatic hydrocarbons (PAHs) are widespread genotoxic environmental pollutants, which require metabolic activation in order to exert biological activities, including mutagenicity and carcinogenicity. Photoactivation is another activation pathway that can lead to PAH genotoxicity. In this paper, we demonstrate that photoirradiation of a series of representative PAHs, with and without bearing a methyl substituent, with UVA light in the presence of methyl linoleate resulted in the formation of methyl linoleate hydroperoxides (a lipid peroxide). The lipid peroxide formation was inhibited by dithiothreitol (DTT) (free radical scavenger), NaN3 (singlet oxygen and free radical scavenger), and superoxide dismutase (SOD) (superoxide scavenger), but was enhanced by the presence of deuterium oxide (D2O) (extends singlet oxygen lifetime). These results suggest that photoirradiation of PAHs by UVA light generates reactive oxygen species (ROS), which induce lipid peroxidation.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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

  2. Stromal haze after combined riboflavin-UVA corneal collagen cross-linking in keratoconus: in vivo confocal microscopic evaluation.

    PubMed

    Mazzotta, Cosimo; Balestrazzi, Angelo; Baiocchi, Stefano; Traversi, Claudio; Caporossi, Aldo

    2007-08-01

    The technique of corneal collagen cross-linking consists of photopolymerization of stromal fibres by the combined action of a photosensitizing substance (riboflavin or vitamin B2) and ultraviolet light from a solid state UVA source. Photopolymerization increases the rigidity of corneal collagen and its resistance to keratectasia. In this report we present two cases, studied through in vivo confocal microscopy, with stage III keratoconus that developed stromal haze after the cross-linking treatment.

  3. 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.

  4. 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.

  5. 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

  6. Experimental reproduction of polymorphous light eruption and benign summer light eruption by whole-body UVA irradiation.

    PubMed

    Lambert, J; Verheyen, A; Dockx, P

    1997-01-01

    The entity 'benign summer light eruption' (BSLE) has been introduced to make a clinical subdivision in the heterogeneous group of polymorphous light eruptions (PLE). Provocation tests for PLE are not always easy to perform and require expensive apparatus. Our purpose was to evaluate a provocation test that could be readily done by a dermatologist with a UVA cabin. Provocation tests are currently required in order to obtain a financial contribution from the social security services in Belgium. In addition, we were interested in determining whether the results of the provocation test would permit us to differentiate between the clinical entities of BSLE and PLE. We studied the efficacy of whole-body UVA irradiation for BSLE and PLE patients. A total of 45 patients was tested, of whom 26 were diagnosed as having BSLE and 19 PLE. In the BSLE group, 24 patients (92%) presented lesions. In the PLE group, 15 patients (79%) had a reaction, but 3 had a positive UVB test. The mean dose to induce lesions was 65.96 J/cm2 for the BSLE group and 52.86 J/cm2 for the PLE group. We conclude that the whole-body UVA test is a high-performance provocation test for both BSLE and PLE patients although it cannot differentiate the two entities from one another.

  7. 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). Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. 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.

  9. 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.

  10. 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.

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

    PubMed Central

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

    2016-01-01

    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. PMID:27006098

  12. 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.

  13. Phototherapy and photopharmacology

    SciTech Connect

    Gasparro, F.P.; Chan, G.; Edelson, R.L.

    1985-11-01

    The activation of 8-methoxypsoralen (8-MOP) by long-wavelength ultraviolet A light (UVA, 320-400 nm) induces the formation of interstrand cross-links in DNA. Psoralen plus UVA (PUVA) is widely used in the treatment of psoriasis, a hyperproliferative disease of the skin. A new psoralen plus UVA therapy has been developed in which the 8-MOP-containing blood of cutaneous T cell lymphoma (CTCL) patients is irradiated with UVA light extracorporeally (i.e., extracorporeal photopheresis). The first group of patients had the leukemic variant of CTCL. A regimen of two treatments on successive days at monthly intervals produced a clinical response in eight of 11 patients. In this review the properties of several psoralens (both naturally occurring and synthetic derivatives) are compared, using several assays (DNA cross-linking, inhibition of lymphocyte response to mitogen stimulation, and cell viability). The development of a panel of monoclonal antibodies that recognize 8-MOP-modified DNA is also described. These antibodies have been used to quantitate 8-MOP photoadduct levels in human DNA samples. In addition to the psoralens, the light activation of two other compounds, gilvocarcin and an insulin-psoralen conjugate, is described.

  14. SPF and UVA-PF sunscreen evaluation: are there good correlations among results obtained in vivo, in vitro and in a theoretical Sunscreen Simulator? A real-life exercise.

    PubMed

    Santos Caetano, J P; Abarca, A P; Guerato, M; Guerra, L; Schalka, S; Perez Simão, D C; Vila, R

    2016-12-01

    Strategies to optimize the development of sunscreens include the use of theoretical sunscreen simulators to predict sun protection factor (SPF) and UVA protection factor (UVA-PF) and in vitro measurements of UVA-PF. The aims of this study were to assess the correlations between (1) SPF and UVA-PF results obtained in a theoretical sunscreen simulator with those observed in vivo (SPF and UVA-PF) and in vitro (UVA-PF) and (2) the results of UVA-PF observed in vitro and in vivo for products in different galenic forms containing or not pigments. BASF Sunscreen Simulator software was used to evaluate the theoretical performance of formulations regarding SPF and UVA protection. In vitroUVA-PF and in vivoSPF were determined for all formulations. UVA-PFin vivo measurements were carried out only on products for which the galenic forms (compact foundations and lip balms) or the presence of dye or pigments could make the results of UVA-PFin vitro less reliable (due to a possible uneven film formation). The results of the SPF calculated by the BASF Sunscreen Simulator presented a very good correlation with SPF observed in vivo in the absence of pigments (r = 0.91; P < 0.05) and a good correlation in the presence of pigments (r = 0.70; P < 0.05). The UVA-PF calculated by the BASF Sunscreen Simulator also exhibited a very good correlation with UVA-PF measured in vitro (r = 0.88; P < 0.05) for the formulations not containing pigment and a good correlation (r = 0.75; P < 0.05) for the formulations containing pigment. The correlation of same UVA-PF calculated by BASF Sunscreen Simulator with UVA-PF measured in vivo for the formulations containing pigment was r = 0.74 (P < 0.05), which is considered good. In addition, the measurements of UVA-PFin vivo presented a good correlation with the values obtained in vitro (r = 0.74; P < 0.05). In the present study, the use of BASF Sunscreen Simulator and in vitroUVA tests showed good correlations with in vivo results and could be considered

  15. Magnesium Silicate Dissolution Investigated by 29Si MAS, 1H-29Si CP MAS, 25Mg QCPMG, and 1H-25Mg CP QCPMG NMR

    SciTech Connect

    Davis, Michael C.; Brouwer, William J.; Wesolowski, David J.; Anovitz, Lawrence M.; Lipton, Andrew S.; Mueller, Karl T.

    2009-08-01

    Olivine has been the subject of frequent investigation in the earth sciences because of its simple structure and rapid dissolution kinetics. Several studies have observed a preferential release of magnesium with respect to silica during weathering under acidic conditions, which has been correlated to the formation of a silicon rich leached layer. While leached layer formation has been inferred through the changing solution chemistry, a thorough spectroscopic investigation of olivine reacted under acidic conditions has not been conducted. In particular, the fate of magnesium in the system is not understood and spectroscopic interrogations through nuclear magnetic resonance can elucidate the changing magnesium coordination and bonding environment. In this study, we combine analysis of the changing solution chemistry with advanced spectroscopic techniques (29Si MAS, 1H-29Si CP MAS, 25Mg QCPMG, and 1H-25Mg 2 CP QCPMG NMR) to probe leached layer formation and possible secondary phase precipitation during the dissolution of forsterite at 150 oC.

  16. A software framework for analysing solid-state MAS NMR data.

    PubMed

    Stevens, Tim J; Fogh, Rasmus H; Boucher, Wayne; Higman, Victoria A; Eisenmenger, Frank; Bardiaux, Benjamin; van Rossum, Barth-Jan; Oschkinat, Hartmut; Laue, Ernest D

    2011-12-01

    Solid-state magic-angle-spinning (MAS) NMR of proteins has undergone many rapid methodological developments in recent years, enabling detailed studies of protein structure, function and dynamics. Software development, however, has not kept pace with these advances and data analysis is mostly performed using tools developed for solution NMR which do not directly address solid-state specific issues. Here we present additions to the CcpNmr Analysis software package which enable easier identification of spinning side bands, straightforward analysis of double quantum spectra, automatic consideration of non-uniform labelling schemes, as well as extension of other existing features to the needs of solid-state MAS data. To underpin this, we have updated and extended the CCPN data model and experiment descriptions to include transfer types and nomenclature appropriate for solid-state NMR experiments, as well as a set of experiment prototypes covering the experiments commonly employed by solid-sate MAS protein NMR spectroscopists. This work not only improves solid-state MAS NMR data analysis but provides a platform for anyone who uses the CCPN data model for programming, data transfer, or data archival involving solid-state MAS NMR data.

  17. Time-Dependent Coupling of Lfm-Helio and MAS Models for CME Propagation

    NASA Astrophysics Data System (ADS)

    Lyon, J.; Merkin, V. G.; Lionello, R.; Linker, J.; Raouafi, N. E.

    2014-12-01

    We present initial results of coupling of the heliospheric adaptation of the Lyon-Fedder-Mobarry (LFM) magnetohydrodynamic (MHD) model — LFM-helio — with the MAS model of the solar corona. Up to now, LFM-helio has been limited to steady-state solutions dominated by corotating structures. We have developed a generalized interface for specification of time-dependent coronal boundary conditions and ingestion of MAS simulation data into the LFM model. The coupling is done by overlapping the LFM inner boundary buffer region with the outer portion of the MAS coronal grid. LFM-helio operates in the inertial rest frame, but our coupling code is sufficiently flexible that MAS solutions performed in either rotating or inertial frames can be ingested. We present results of a number of idealized coupled MAS/LFM-helio simulations — ranging from simply symmetric solar wind background to realistic including high and slow speed streams — intended to test the interface for seamless propagation of transients from the corona into the inner heliosphere domain. The transients are then tracked to larger heliocentric distances — to Earth and beyond. We specifically investigate the magnetic structure of the CMEs as they propagate through the interplanetary medium including rotation and erosion, and consider how the simulation resolution affects the results. We also developed codes for creation of synthetic white-light heliographic images which are used to help track CMEs kinematics through J-maps and put the simulations into a realistic observational context.

  18. The ACE2/Ang-(1-7)/Mas axis can inhibit hepatic insulin resistance.

    PubMed

    Cao, Xi; Yang, Fang-Yuan; Xin, Zhong; Xie, Rong-Rong; Yang, Jin-Kui

    2014-08-05

    Blocking the renin-angiotensin system (RAS) can reduce the risk of diabetes. Meanwhile, the angiotensin (Ang)-converting enzyme-2 (ACE2)/Ang-(1-7)/Mas axis has recently been proposed to function as a negative regulator of the RAS. In previous studies, we first demonstrated that ACE2 knockout (ACE2(-/)(y)) mice exhibit impaired glucose tolerance or diabetes. However the precise roles of ACE2 on glucose metabolism are unknown. Here we show that the ACE2/Ang-(1-7)/Mas axis can ameliorate insulin resistance in the liver. Activation of the ACE2/Ang-(1-7)/Mas axis increases glucose uptake and decreases glycogen synthesis in the liver accompanied by increased expression of glucose transporters, insulin receptor substrates and decreased expression of enzymes for glycogen synthesis. ACE2 knockout mice displayed elevated levels of oxidative stress and exposure to Ang-(1-7) reduced the stress in hepatic cells. As a consequence of anti-oxidative stress, activation of the ACE2/Ang-(1-7)/Mas axis led to improved hepatic insulin resistance through the Akt/PI3K/IRS-1/JNK insulin signaling pathway. This is the first time documented that the ACE2/Ang-(1-7)/Mas axis can ameliorate insulin resistance in the liver. As insulin resistance in the liver is considered to be the primary cause of the development of type 2 diabetes, this axis may serve as a new diabetes target. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  19. Evidence for a Systematic Offset of -0.25 mas in the Gaia DR1 Parallaxes

    NASA Astrophysics Data System (ADS)

    Stassun, Keivan G.; Torres, Guillermo

    2016-11-01

    We test the parallaxes reported in the Gaia first data release using the sample of eclipsing binaries with accurate, empirical distances from Stassun & Torres. We find an average offset of -0.25 ± 0.05 mas in the sense of the Gaia parallaxes being too small (i.e., the distances too long). The offset does not depend strongly on obvious parameters such as color or brightness. However, we find with high confidence that the offset may depend on ecliptic latitude: the mean offset is -0.38 ± 0.06 mas in the ecliptic north and -0.05 ± 0.09 mas in the ecliptic south. The ecliptic latitude dependence may also be represented by the linear relation, {{Δ }}π ≈ -0.22(+/- 0.05)-0.003(+/- 0.001)× β mas (β in degrees). Finally, there is a possible dependence of the parallax offset on distance, with the offset becoming negligible for π ≲ 1 mas; we discuss whether this could be caused by a systematic error in the eclipsing binary distance scale, and reject this interpretation as unlikely.

  20. 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

  1. Antimicrobial susceptibility of photodynamic therapy (UVA/riboflavin) against Staphylococcus aureus.

    PubMed

    Kashiwabuchi, Renata Tiemi; Khan, Yasin; Carvalho, Fabio Ramos de Souza; Hirai, Flavio; Campos, Mauro Silveira; McDonnell, Peter John

    2012-01-01

    To assess S. aureus in vitro viability after the exposure to ultraviolet light A (UVA) and riboflavin (B2). Samples of S. aureus in 96 well plates (in triplicate) were exposed to riboflavin (B2) and ultraviolet light A (365 nm wavelength) at a power density of 3 mW/cm², 8 mm spot diameter, for 30 minutes. Control groups were prepared as well in triplicate: blank control, ultraviolet light A only, riboflavin only and dead bacteria Control. The bacterial viability was measured using fluorescent microscopy. In order to investigate the occurrence of "viable but non-culturable" microorganisms after treatment, the cell viability was also investigated by plate culture procedure onto a broth medium. Statistical analysis was performed using the triplicate values from each experimental condition. No difference was observed among the treatment group and the control samples (p=1). The combination of riboflavin 0.1% and ultraviolet light A at 365 nm did not exhibit antimicrobial activity against oxacillin susceptible S. aureus.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. Homogeneous and heterogeneous degradation of caffeic acid using photocatalysis driven by UVA and solar light.

    PubMed

    Yáñez, Eliana; Santander, Paola; Contreras, David; Yáñez, Jorge; Cornejo, Lorena; Mansilla, Héctor D

    2016-01-01

    Waste water from the wine industry is characterized by a high concentration of dissolved organic matter and the presence of natural phenolic compounds with low biodegradability. High concentrations of phenolic compounds may cause environmental pollution and risks to human health. In this article caffeic acid (CA) was used as a model compound of wine effluent because it is refractory to the conventional wastewater treatments. The oxidation of caffeic acid in water solution (0.01 g L(-1)) by heterogeneous photocatalysis and photo-Fenton reaction was studied using UVA. The optimal conditions for each treatment were performed by multivariate experimental design. The optimal conditions for heterogeneous photocatalysis were pH 5.3 and 0.9 g L(-1) TiO2. In the case of photo-Fenton treatment, optimized variable were 82.4 μmol L(-1) of Fe(2+) and 558.6 μmol L(-1) of H2O2. The degradation profiles of CA were monitored by UV-Vis, HPLC, TOC and COD. To reach 90% of CA removal, 40 and 2 min of reaction, respectively, were required by heterogeneous and photo-Fenton processes, respectively. For comparison purposes, the reactions were also performed under solar light. The use of solar light does not change the efficiency of the photo-Fenton reaction, yet the performance of the heterogeneous process was significantly improved, reaching 90% of degradation in 15 min.

  10. 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.

  11. Heterogeneous photodegradation of pentachlorophenol and iron cycling with goethite, hematite and oxalate under UVA illumination.

    PubMed

    Lan, Qing; Li, Fang-bai; Sun, Cui-xiang; Liu, Cheng-shuai; Li, Xiang-zhong

    2010-02-15

    Heterogeneous photodegradation of pentachlorophenol (PCP) in the goethite (alpha-FeOOH) and hematite (alpha-Fe(2)O(3)) systems with oxalate under UVA illumination was investigated. The PCP degradation, dechlorination and detoxification, in terms of Microtox acute toxicity, were all achieved to the higher efficiency in the hematite suspension than in the goethite suspension. The optimal initial concentration of oxalic acid (C(ox)(0)) for the PCP degradation with goethite and hematite under the experimental conditions was found to be 1.2mM, since sufficient Fe(III) as Fe(C(2)O(4))(3)(3-) and Fe(II) as Fe(C(2)O(4))(2)(2-) can be formed at C(ox)(0)>or=1.2mM. The main intermediates of PCP degradation were identified by GC-MS, HPLC and IC analyses. It was found that the cycling process between Fe(III) and Fe(II) in both the goethite and hematite systems occurred more vigorously at the initial stage and gradually became gentle, while the rate of PCP photodegradation varied from fast to slow during the reaction time. Furthermore, the formation of H(2)O(2) during photoreaction was studied to explore its relationship with the photodegradation efficiency and the iron cycling process.

  12. 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)

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. Technology Enhanced Learning for People with Intellectual Disabilities and Cerebral Paralysis: The MAS Platform

    NASA Astrophysics Data System (ADS)

    Colomo-Palacios, Ricardo; Paniagua-Martín, Fernando; García-Crespo, Ángel; Ruiz-Mezcua, Belén

    Education for students with disabilities now takes place in a wide range of settings, thus, including a wider range of assistive tools. As a result of this, one of the most interesting application domains of technology enhanced learning is related to the adoption of learning technologies and designs for people with disabilities. Following this unstoppable trend, this paper presents MAS, a software platform aimed to help people with severe intellectual disabilities and cerebral paralysis in their learning processes. MAS, as a technology enhanced learning platform, provides several tools that supports learning and monitoring for people with special needs, including adaptative games, data processing and monitoring tools. Installed in a special needs education institution in Madrid, Spain, MAS provides special educators with a tool that improved students education processes.

  1. MAS-Based Cooperative Control for Biotechnological Process-A Case Study

    NASA Astrophysics Data System (ADS)

    Choinski, Dariusz; Metzger, Mieczyslaw; Nocon, Witold

    The MAS-based control seems to be better suited for manufacturing control because of its discrete event character. Nevertheless, for continuous industrial processes the MAS-based control can be also very attractive. In this paper, a synthesis of the MAS-based control system for the continuous process is presented. A biological reactor is controlled using respirometric approach. In this approach, both standard control loops and additional experiments are performed to obtain measurements not available on-line. Therefore, the system consists of different control agents being able to cooperate or to inhibit each other in order to achieve the appropriate goals. A case study experiments are realized using an experimental wastewater treatment pilot plant.

  2. Investigation of domain size in polymer membranes using double quantum filtered spin diffusion MAS NMR.

    SciTech Connect

    Fujimoto, Cy H.; Alam, Todd Michael; Cherry, Brian Ray; Cornelius, Christopher James

    2005-02-01

    Solid-state {sup 1}H magic angle spinning (MAS) NMR was used to investigate sulfonated Diels-Alder poly(phenlylene) polymer membranes. Under high spinning speed {sup 1}H MAS conditions, the proton environments of the sulfonic acid and phenylene polymer backbone are resolved. A double-quantum (DQ) filter using the rotor-synchronized back-to-back (BABA) NMR multiple-pulse sequence allowed the selective suppression of the sulfonic proton environment in the {sup 1}H MAS NMR spectra. This DQ filter in conjunction with a spin diffusion NMR experiment was then used to measure the domain size of the sulfonic acid component within the membrane. In addition, the temperature dependence of the sulfonic acid spin-spin relaxation time (T{sub 2}) was determined, providing an estimate of the activation energy for the proton dynamics of the dehydrated membrane.

  3. (1)H HR-MAS NMR-based metabolomics analysis for dry-fermented sausage characterization.

    PubMed

    García-García, Ana Belén; Lamichhane, Santosh; Castejón, David; Cambero, Mª Isabel; Bertram, Hanne Christine

    2018-02-01

    Proton high-resolution magic angle spinning ((1)H HR-MAS) nuclear magnetic resonance (NMR) spectroscopy in combination with principal component analysis (PCA) was employed to characterize dry-fermented sausages salchichón type throughout the manufacturing process. (1)H HR-MAS NMR metabolite profiling was achieved from a small sample of intact sausage after 0, 2, 4, 7, 11 and 14days of drying. Intriguingly, the obtained results enabled the identification of the three main stages in the traditional production of salchichón. Formulation, fermentation and drying-ripening periods showed distinct and characteristic metabolomic profiles. Compositional changes related to microbial activity, as well as proteolytic and lipolytic phenomena, decisive steps in such a ripening process, could be monitored through the NMR spectra. This study shows the potential of (1)H HR-MAS as a rapid method for probing metabolomic profiles and compositional changes during sausages processing. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Factor analysis of 27Al MAS NMR spectra for identifying nanocrystalline phases in amorphous geopolymers.

    PubMed

    Urbanova, Martina; Kobera, Libor; Brus, Jiri

    2013-11-01

    Nanostructured materials offer enhanced physicochemical properties because of the large interfacial area. Typically, geopolymers with specifically synthesized nanosized zeolites are a promising material for the sorption of pollutants. The structural characterization of these aluminosilicates, however, continues to be a challenge. To circumvent complications resulting from the amorphous character of the aluminosilicate matrix and from the low concentrations of nanosized crystallites, we have proposed a procedure based on factor analysis of (27)Al MAS NMR spectra. The capability of the proposed method was tested on geopolymers that exhibited various tendencies to crystallize (i) completely amorphous systems, (ii) X-ray amorphous systems with nanocrystalline phases, and (iii) highly crystalline systems. Although the recorded (27)Al MAS NMR spectra did not show visible differences between the amorphous systems (i) and the geopolymers with the nanocrystalline phase (ii), the applied factor analysis unambiguously distinguished these materials. The samples were separated into the well-defined clusters, and the systems with the evolving crystalline phase were identified even before any crystalline fraction was detected by X-ray powder diffraction. Reliability of the proposed procedure was verified by comparing it with (29)Si MAS NMR spectra. Factor analysis of (27)Al MAS NMR spectra thus has the ability to reveal spectroscopic features corresponding to the nanocrystalline phases. Because the measurement time of (27)Al MAS NMR spectra is significantly shorter than that of (29)Si MAS NMR data, the proposed procedure is particularly suitable for the analysis of large sets of specifically synthesized geopolymers in which the formation of the limited fractions of nanocrystalline phases is desired.

  5. Pulsed field gradient multiple-quantum MAS NMR spectroscopy of half-integer spin quadrupolar nuclei

    NASA Astrophysics Data System (ADS)

    Fyfe, C. A.; Skibsted, J.; Grondey, H.; Meyer zu Altenschildesche, H.

    1997-12-01

    Pulsed field gradients (PFGs) have been applied to select coherence transfer pathways in multiple-quantum (MQ) MAS NMR spectra of half-integer spin quadrupolar nuclei in rigid solids. 27Al triple-quantum (3Q) MAS NMR spectra of the aluminophosphate molecular sieves VPI-5 and AlPO 4-18 have been used to demonstrate the selection of the (0)→(3)→(-1) coherence transfer pathway using PFGs and no phase cycling. Compared to MQMAS experiments that employ phase cycling schemes, the main advantage of the PFG-MQMAS technique is its simplicity, which should facilitate the combination of MQMAS with other pulse sequences.

  6. 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

  7. [Effect of various compositions of riboflavin eye drops on the intraoperative corneal thickness during UVA-cross-linking in keratoconus eyes].

    PubMed

    Vetter, J M; Tubic-Grozdanis, M; Faust, M; Lorenz, K; Gericke, A; Stoffelns, B M

    2011-06-01

    During the UVA-cross-linking treatment in keratoconus patients, the UVA rays are partially absorbed in the stroma of the riboflavin-loaded cornea. This effect protects the corneal endothelium from UVA irradiation damage. The intensity of UVA light reaching the endothelium is inversely correlated with corneal thickness. The common composition of riboflavin eye drops may lead to a marked reduction in corneal thickness increasing the risk of endothelial damage. In a retrospective analysis of 23 UVA-cross-linking procedures on 23 patients we collected data about the pre-, intra- and postoperative corneal thickness (measured with ultrasound). Among these patients and depending on the preoperative state, 8 eyes received Medio Cross (TM) eye drops (group 1), 8 eyes received Medio Cross (TM) eye drops combined with riboflavin 0.1 %/methylhydroxypropylcellulose 1,5 %/NaCl 1.1 % (group 2) and 7 eyes received riboflavin 0.2 %/methylhydroxypropylcellulose 0.5 %/NaCl 0.7 % eye drops (group 3) before and during UVA irradiation. Data are presented as means ± standard deviation. A comparison of the data was performed using (one-way) ANOVA. The mean corneal thickness at the end of the UVA cross-linking procedure was 67 ± 9 % (means ± standard deviation) of preoperative thickness in group 1, 118 ± 14 % in group 2 and 140 ± 23 % in group 3. The values in groups 2 and 3 were significantly different from those in the reference group 1. Our results show a strong variability of the postoperative corneal thickness using different standard compositions of riboflavin eye drops. Further studies are needed to find a composition of riboflavin eye drops ensuring a moderate increase in intraoperative corneal thickness to protect the corneal endothelium. © Georg Thieme Verlag KG Stuttgart · New York.

  8. Human amnion-derived mesenchymal stem cells protect against UVA irradiation-induced human dermal fibroblast senescence, in vitro.

    PubMed

    Zhang, Chunli; Yuchi, Haishen; Sun, Lu; Zhou, Xiaoli; Lin, Jinde

    2017-08-01

    The aim of the present study was to determine if human amnion‑derived mesenchymal stem cells (HAMSCs) exert a protective effect on ultraviolet A (UVA) irradiation-induced human dermal fibroblast (HDF) senescence. A senescence model was constructed as follows: HDFs (104‑106 cells/well) were cultured in a six‑well plate in vitro and then exposed to UVA irradiation at 9 J/cm2 for 30 min. Following the irradiation period, HDFs were co‑cultured with HAMSCs, which were seeded on transwells. A total of 72 h following the co‑culturing, senescence‑associated β‑galactosidase staining was performed and reactive oxygen species (ROS) content and mitochondrial membrane potential (Δψm) were detected in the HDFs via flow cytometric analysis. The results demonstrated that the percentage of HDFs, detected via staining with X‑gal, were markedly decreased when co‑cultured with human HAMSCs, compared with the group that were not co‑cultured. The ROS content was decreased and the mitochondrial membrane potential (Δψm) recovered in cells treated with UVA and HAMSCs, compared with that of cells treated with UVA alone. Reverse transcription‑quantitative polymerase chain reaction revealed the significant effects of HAMSCs on the HDF senescence marker genes p53 and matrix metalloproteinase‑1 mRNA expression. In addition to this, western blot analysis verified the effects of HAMSCs on UVA induced senescence, providing a foundation for novel regenerative therapeutic methods. Furthermore, the results suggested that activation of the extracellular‑signal regulated kinase 1/2 mitogen activated protein kinase signal transduction pathway, is essential for the HAMSC‑mediated UVA protective effects. The decrease in ROS content additionally indicated that HAMSCs may exhibit the potential to treat oxidative stress‑mediated UVA skin senescence in the future.

  9. Evaluation of drug and sunscreen permeation via skin irradiated with UVA and UVB: comparisons of normal skin and chronologically aged skin.

    PubMed

    Hung, Chi-Feng; Fang, Chia-Lang; Al-Suwayeh, Saleh A; Yang, Shih-Yung; Fang, Jia-You

    2012-12-01

    Ultraviolet (UV) exposure is the predominant cause of skin aging. A systematic evaluation of drug skin permeation via photoaged skin is lacking. The aim of this work was to investigate whether UVA and UVB affect absorption by the skin of drugs and sunscreens, including tetracycline, quercetin, and oxybenzone. The dorsal skin of nude mice was subjected to UVA (24 and 39 J/cm(2)) or UVB (150, 200, and 250 mJ/cm(2)) irradiation. Levels of skin water loss, erythema, and sebum were evaluated, and histological examinations of COX-2 and claudin-1 expressions were carried out. Permeation of the permeants into and through the skin was determined in vitro using a Franz cell. In vivo skin uptake was also evaluated. Senescent skin (24 weeks old) was used for comparison. Wrinkling and scaling were significant signs of skin treated with UVA and UVB, respectively. The level of claudin-1, an indicator of tight junctions (TJs), was reduced by UVA and UVB irradiation. UVA enhanced tetracycline and quercetin skin deposition by 11- and 2-fold, respectively. A similar enhancement was shown for flux profiles. Surprisingly, a lower UVA dose revealed greater enhancement compared to the higher dose. The skin deposition and flux of tetracycline both decreased with UVB exposure. UVB also significantly reduced quercetin flux. The skin absorption behavior of chronologically aged skin approximated that of the UVA group, with photoaged skin showing higher enhancement. UV generally exhibited a negligible effect on modulating oxybenzone permeation. Skin disruption produced by UV does not necessarily result in enhanced skin absorption. It depends on the UV wavelength, irradiated energy, and physicochemical properties of the permeant. To the best of our knowledge, this is the first report establishing drug permeation profiles for UV-irradiated skin. Copyright © 2012 Japanese Society for Investigative Dermatology. Published by Elsevier Ireland Ltd. All rights reserved.

  10. Oxidative degradation of emerging micropollutant acesulfame in aqueous matrices by UVA-induced H2O2/Fe(2+) and S2O8(2-)/Fe(2+) processes.

    PubMed

    Kattel, Eneliis; Trapido, Marina; Dulova, Niina

    2017-03-01

    In the present study, UVA/H2O2/Fe(2+) and UVA/S2O8(2-)/Fe(2+) processes were applied to degrade the artificial sweetener, acesulfame (ACE) in ultrapure water (UW), groundwater (GW), and secondary effluent (WW). The degradation time and mineralization of 75 μM of ACE determined the efficacy of the procedures. The results indicated that the UVA-induced H2O2/Fe(2+) and S2O8(2-)/Fe(2+) systems are a promising alternative for the removal of ACE from different aqueous matrices as both studied processes completely degraded the target compound at an ACE/oxidant/Fe(2+) molar ratio of 1/10/1 and pH 3. In the case of UVA-induced systems application without pH adjustment, the ACE decomposition was achieved only in ultrapure water. The maximum mineralization of ACE in ultrapure water by the UVA/H2O2/Fe(2+) system (molar ratio of 1/10/1) at pH 3 resulted in residual TOC of 18.3%. The oxidative effectiveness of the UVA/S2O8(2-)/Fe(2+) system was proved to be mainly formed by the hydroxyl radicals. The obtained results indicate that UVA light can be successfully used for the oxidation of the studied artificial sweetener in various aqueous matrices with carefully adjusted process conditions.

  11. Expression and cellular localization of the Mas receptor in the adult and developing mouse retina

    PubMed Central

    Prasad, Tuhina; Verma, Amrisha

    2014-01-01

    Purpose Recent studies have provided evidence that a local renin-angiotensin system (RAS) exists in the retina and plays an important role in retinal neurovascular function. We have recently shown that increased expression of ACE2 and angiotensin (1-7) [Ang (1-7)], two components of the protective axis of the RAS, in the retina via adeno-associated virus (AAV)-mediated gene delivery, conferred protection against diabetes-induced retinopathy. We hypothesized that the protective molecular and cellular mechanisms of Ang (1-7) are mediated by its receptor, Mas, and the expression level and cellular localization dictate the response to Ang (1-7) and activation of subsequent protective signaling pathways. We tested this hypothesis by examining the expression and cellular localization of the Mas receptor in adult and developing mouse retinas. Methods The cellular localization of the Mas receptor protein was determined with immunofluorescence of the eyes of adult and postnatal day 1 (P1), P5, P7, P15, and P21 mice using the Mas receptor-specific antibody, and mRNA was detected with in situ hybridization of paraffin-embedded sections. Western blotting and real-time reverse-transcription (RT)–PCR analysis were performed to determine the relative levels of the Mas protein and mRNA in adult and developing retinas, as well as in cultured retinal Müller glial and RPE cells. Results In the adult eye, the Mas receptor protein was abundantly present in retinal ganglion cells (RGCs) and photoreceptor cells; a lower level of expression was observed in endothelial cells, Müller glial cells, and other neurons in the inner nuclear layer of the retina. In the developing retina, Mas receptor mRNA and protein expression was detected in the inner retina at P1, and the expression levels increased with age to reach the adult level and pattern by P15. In the adult mouse retina, Mas receptor mRNA was expressed at a much higher level when compared to angiotensin II (Ang II) type I (AT1R) and

  12. 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

  13. Acceptance Test Report for the Modular Automation System (MAS) Manufactured by Honeywell Inc.

    SciTech Connect

    ANDERSON, D.L.

    2000-02-01

    This document details the performance of the acceptance test of the Honeywell MAS Control System for equipment to be installed in gloveboxes HA-20MB and HA-211 at a later date. Equipment that was anticipated included 6 stabilization furnaces, only three and their associated equipment were installed.

  14. Advanced instrumentation for DNP-enhanced MAS NMR for higher magnetic fields and lower temperatures

    NASA Astrophysics Data System (ADS)

    Matsuki, Yoh; Idehara, Toshitaka; Fukazawa, Jun; Fujiwara, Toshimichi

    2016-03-01

    Sensitivity enhancement of MAS NMR using dynamic nuclear polarization (DNP) is gaining importance at moderate fields (B0 < 9 T) and temperatures (T > 90 K) with potential applications in chemistry and material sciences. However, considering the ever-increasing size and complexity of the systems to be studied, it is crucial to establish DNP under higher field conditions, where the spectral resolution and the basic NMR sensitivity tend to improve. In this perspective, we overview our recent efforts on hardware developments, specifically targeted on improving DNP MAS NMR at high fields. It includes the development of gyrotrons that enable continuous frequency tuning and rapid frequency modulation for our 395 GHz-600 MHz and 460 GHz-700 MHz DNP NMR spectrometers. The latter 700 MHz system involves two gyrotrons and a quasi-optical transmission system that combines two independent sub-millimeter waves into a single dichromic wave. We also describe two cryogenic MAS NMR probe systems operating, respectively, at T ∼100 K and ∼30 K. The latter system utilizes a novel closed-loop helium recirculation mechanism, achieving cryogenic MAS without consuming any cryogen. These instruments altogether should promote high-field DNP toward more efficient, reliable and affordable technology. Some experimental DNP results obtained with these instruments are presented.

  15. Advanced instrumentation for DNP-enhanced MAS NMR for higher magnetic fields and lower temperatures.

    PubMed

    Matsuki, Yoh; Idehara, Toshitaka; Fukazawa, Jun; Fujiwara, Toshimichi

    2016-03-01

    Sensitivity enhancement of MAS NMR using dynamic nuclear polarization (DNP) is gaining importance at moderate fields (B0<9T) and temperatures (T>90K) with potential applications in chemistry and material sciences. However, considering the ever-increasing size and complexity of the systems to be studied, it is crucial to establish DNP under higher field conditions, where the spectral resolution and the basic NMR sensitivity tend to improve. In this perspective, we overview our recent efforts on hardware developments, specifically targeted on improving DNP MAS NMR at high fields. It includes the development of gyrotrons that enable continuous frequency tuning and rapid frequency modulation for our 395 GHz-600 MHz and 460 GHz-700 MHz DNP NMR spectrometers. The latter 700 MHz system involves two gyrotrons and a quasi-optical transmission system that combines two independent sub-millimeter waves into a single dichromic wave. We also describe two cryogenic MAS NMR probe systems operating, respectively, at T ∼ 100K and ∼ 30K. The latter system utilizes a novel closed-loop helium recirculation mechanism, achieving cryogenic MAS without consuming any cryogen. These instruments altogether should promote high-field DNP toward more efficient, reliable and affordable technology. Some experimental DNP results obtained with these instruments are presented. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  16. An Analysis of the Rise and Fall of the AA-MAS Policy

    ERIC Educational Resources Information Center

    Lazarus, Sheryl S.; Thurlow, Martha L.; Ysseldyke, James E.; Edwards, Lynn M.

    2015-01-01

    In 2005, to address concerns about students who might fall in the "gap" between the regular assessment and the alternate assessment based on alternate achievement standards (AA-AAS), the U.S. Department of Education announced that states could develop alternate assessments based on modified achievement standards (AA-MAS). This article…

  17. Successfully Transitioning from the AA-MAS to the General Assessment. NCEO Policy Directions. Number 22

    ERIC Educational Resources Information Center

    Lazarus, Sheryl; Thurlow, Martha; Christensen, Laurene; Shyyan, Vitaliy

    2014-01-01

    Federal policy initiatives such as the flexibility waivers for accountability are requiring that states transition away from the use of an alternate assessment based on modified achievement standards (AA-MAS). It is expected that those students who had participated in that assessment will instead participate in the state's general assessment (or a…

  18. Considerations for Consortia as States Transition Away from AA-MAS. NCEO Brief. Number 7

    ERIC Educational Resources Information Center

    National Center on Educational Outcomes, 2014

    2014-01-01

    States with an alternate assessment based on modified achievement standards (AA-MAS) that received a flexibility waiver from some of the requirements of No Child Left Behind are required to phase out their use of this assessment. And, on August 23, 2013, the U.S. Department of Education published a proposed rollback of regulation that allowed the…

  19. Moderate MAS enhances local (1)H spin exchange and spin diffusion.

    PubMed

    Roos, Matthias; Micke, Peter; Saalwächter, Kay; Hempel, Günter

    2015-11-01

    Proton NMR spin-diffusion experiments are often combined with magic-angle spinning (MAS) to achieve higher spectral resolution of solid samples. Here we show that local proton spin diffusion can indeed become faster at low (<10 kHz) spinning rates as compared to static conditions. Spin diffusion under static conditions can thus be slower than the often referred value of 0.8 nm(2)/ms, which was determined using slow MAS (Clauss et al., 1993). The enhancement of spin diffusion by slow MAS relies on the modulation of the orientation-dependent dipolar couplings during sample rotation and goes along with transient level crossings in combination with dipolar truncation. The experimental finding and its explanation is supported by density matrix simulations, and also emphasizes the sensitivity of spin diffusion to the local coupling topology. The amplification of spin diffusion by slow MAS cannot be explained by any model based on independent spin pairs; at least three spins have to be considered. Copyright © 2015 Elsevier Inc. All rights reserved.

  20. An Analysis of the Rise and Fall of the AA-MAS Policy

    ERIC Educational Resources Information Center

    Lazarus, Sheryl S.; Thurlow, Martha L.; Ysseldyke, James E.; Edwards, Lynn M.

    2015-01-01

    In 2005, to address concerns about students who might fall in the "gap" between the regular assessment and the alternate assessment based on alternate achievement standards (AA-AAS), the U.S. Department of Education announced that states could develop alternate assessments based on modified achievement standards (AA-MAS). This article…

  1. Characterization and significance of ACE2 and Mas receptor in human colon adenocarcinoma.

    PubMed

    Bernardi, Stella; Zennaro, Cristina; Palmisano, Silvia; Velkoska, Elena; Sabato, Nicoletta; Toffoli, Barbara; Giacomel, Greta; Buri, Luigi; Zanconati, Fabrizio; Bellini, Giuseppe; Burrell, Louise M; De Manzini, Nicolò; Fabris, Bruno

    2012-03-01

    A new arm of the renin-angiotensin system (RAS) has been recently characterized; this includes angiotensin converting enzyme (ACE)2 and angiotensin (Ang)1-7, a heptapeptide acting through the Mas receptor (MasR). Recent studies show that Ang1-7 has an antiproliferative action on lung adenocarcinoma cells. The aim of this study was to characterize RAS expression in human colon adenocarcinoma and to investigate whether Ang1-7 exerts an antiproliferative effect on human colon adenocarcinoma cells. Gene, protein expression and enzymatic activity of the main components of the RAS were determined on non-neoplastic colon mucosa as well as on the tumor mass and the mucosa taken 5 cm distant from it, both collected from patients with colon adenocarcinoma. Two different human colon cancer cell lines were treated with AngII and Ang1-7. The novel finding of this study was that MasR was significantly upregulated in colon adenocarcinoma compared with non-neoplastic colon mucosa, which showed little or no expression of it. ACE gene expression and enzymatic activity were also increased in the tumors. However, AngII and Ang1-7 did not have any pro-/antiproliferative effects in the cell lines studied. The data suggest that upregulation of the MasR could be used as a diagnostic marker of colon adenocarcinoma.

  2. 47 CFR 101.1317 - Competitive bidding procedures for mutually exclusive MAS EA applications.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 5 2014-10-01 2014-10-01 false Competitive bidding procedures for mutually exclusive MAS EA applications. 101.1317 Section 101.1317 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES FIXED MICROWAVE SERVICES Multiple Address Systems...

  3. The Multidimensional Attitudes Scale toward Persons with Disabilities (MAS): Construction and Validation

    ERIC Educational Resources Information Center

    Findler, Liora; Vilchinsky, Noa; Werner, Shirli

    2007-01-01

    This study presents the development of a new instrument, the "Multidimensional Attitudes Scale Toward Persons With Disabilities" (MAS). Based on the multidimensional approach, it posits that attitudes are composed of three dimensions: affect, cognition, and behavior. The scale was distributed to a sample of 132 people along with a…

  4. Performance of RINEPT is amplified by dipolar couplings under ultrafast MAS conditions.

    PubMed

    Zhang, Rongchun; Ramamoorthy, Ayyalusamy

    2014-06-01

    The refocused insensitive nuclei enhanced by polarization transfer (RINEPT) technique is commonly used for heteronuclear polarization transfer in solution and solid-state NMR spectroscopy. Suppression of dipolar couplings, either by fast molecular motions in solution or by a combination of MAS and multiple pulse sequences in solids, enables the polarization transfer via scalar couplings. However, the presence of unsuppressed dipolar couplings could alter the functioning of RINEPT, particularly under fast/ultrafast MAS conditions. In this study, we demonstrate, through experiments on rigid solids complemented by numerical simulations, that the polarization transfer efficiency of RINEPT is dependent on the MAS frequency. In addition, we show that heteronuclear dipolar coupling is the dominant factor in the polarization transfer, which is strengthened by the presence of (1)H-(1)H dipolar couplings. In fact, the simultaneous presence of homonuclear and heteronuclear dipolar couplings is the premise for the polarization transfer by RINEPT, whereas the scalar coupling plays an insignificant role under ultrafast MAS conditions on rigid solids. Our results additionally reveal that the polarization transfer efficiency decreases with the increasing duration of RF pulses used in the RINEPT sequence.

  5. 48 CFR 538.270 - Evaluation of multiple award schedule (MAS) offers.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 4 2010-10-01 2010-10-01 false Evaluation of multiple... and Administering Federal Supply Schedules 538.270 Evaluation of multiple award schedule (MAS) offers... determining the Government's price negotiation objectives, consider the following factors: (1)...

  6. 77 FR 58996 - Multiple Award Schedule (MAS) Program Continuous Open Season-Operational Change; Extension of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-09-25

    ... ADMINISTRATION Multiple Award Schedule (MAS) Program Continuous Open Season-- Operational Change; Extension of Comment Period AGENCY: Federal Acquisition Service (FAS), General Services Administration (GSA). ACTION... Administration (GSA), Federal Acquisition Service (FAS) issued a notice on July 23, 2012. The comment period is...

  7. Photodegradation of orange I in the heterogeneous iron oxide-oxalate complex system under UVA irradiation.

    PubMed

    Lei, Jing; Liu, Chengshuai; Li, Fangbai; Li, Xiaomin; Zhou, Shungui; Liu, Tongxu; Gu, Minghua; Wu, Qitang

    2006-09-21

    To understand the photodegradation of azo dyes in natural aquatic environment, a novel photo-Fenton-like system, the heterogeneous iron oxide-oxalate complex system was set up with the existence of iron oxides and oxalate. Five iron oxides, including gamma-FeOOH, IO-250, IO-320, IO-420 and IO-520, were prepared and their adsorption capacity was investigated in the dark. The results showed that the saturated adsorption amount (gamma(max)) was ranked the order of IO-250 > IO-320 > gamma-FeOOH > IO-420 > IO-520 and the adsorption equilibrium constant (Ka) followed the order of IO-250 > IO-520 > gamma-FeOOH > IO-420 > IO-320. The effect of initial pH value, the initial concentrations of oxalate and orange I on the photodegradation of orange I were also investigated in different iron oxide-oxalate systems. The results showed that the photodegradation of orange I under UVA irradiation could be enhanced greatly in the presence of oxalate. And the optimal oxalate concentrations (C(ox)0) for gamma-FeOOH, IO-250, IO-320, IO-420 and IO-520 were 1.8, 1.6, 3.5, 3.0 and 0.8 mM, respectively. The photodegradation of orange I in the presence of optimal C(ox)0 was ranked as the order of gamma-FeOOH > IO-250 > IO-320 > IO-420 > IO-520. The optimal range of initial pH was at about 3-4. The first-order kinetic constant for the degradation of orange I decreased with the increase in the initial concentration of orange I. Furthermore, the variation of pH, the concentrations of Fe3+ and Fe2+ during the photoreaction were also strongly dependent on the C(ox)0 and iron oxides.

  8. 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(-). Copyright © 2015 Elsevier Ltd. All rights reserved.

  9. Photochemical treatment of plasma with amotosalen and UVA light: process validation in three European blood centers.

    PubMed

    Schlenke, Peter; Hervig, Tor; Isola, Hervé; Wiesel, Marie-Louise; Kientz, Daniel; Pinkoski, Linda; Singh, Yasmin; Lin, Lily; Corash, Laurence; Cazenave, Jean-Pierre

    2008-04-01

    A photochemical treatment (PCT) process has been developed to inactivate pathogens and white blood cells (WBCs) in therapeutic plasma. Process validation studies were performed in three European blood centers under routine operating conditions. Each center prepared 30 apheresis and 30 to 36 whole blood-derived plasma units for PCT. Each whole blood-derived plasma unit contained a mixture of two to three matched donations. After removal of pretreatment control samples (control fresh-frozen plasma [C-FFP]), 546 to 635 mL of plasma was treated with 15 mL of 6 mmol per L amotosalen, 3 J per cm(2) UVA treatment, and removal of residual amotosalen with a compound adsorption device. After processing, plasma samples (PCT-FFP) were withdrawn, frozen at -60 degrees C within 8 hours of collection, and assayed for coagulation factors and residual amotosalen. A total of 186 units of plasma were processed. The mean prothrombin time (12.2 +/- 0.6 sec) and activated partial thromboplastin time (32.1 +/- 3.2 sec) of PCT-FFP were slightly prolonged compared to C-FFP. Fibrinogen and Factor (F)VIII were most sensitive to PCT (26% mean reduction). PCT-FFP, however, retained sufficient levels of fibrinogen (217 +/- 43 mg/dL) and FVIII (97 +/- 29 IU/dL) for therapeutic plasma. Mean levels of FII, FV, FVII, F IX, FX, FXI, and FXIII in PCT-FFP were comparable to C-FFP (81%-97% retention of activity). Antithrombotic proteins were not significantly affected by PCT with retention ranging between 83 and 97 percent. Mean residual amotosalen levels were 0.6 +/- 0.1 micromol per L. Process validation studies in three European centers demonstrated retention of coagulation factors in PCT-FFP within the required European and respective national standards for therapeutic plasma.

  10. Ultra High Angular Resolution and sub-mas Astrometry with HST's FGS1r

    NASA Astrophysics Data System (ADS)

    Lallo, M.; Makidon, R. B.; Jong, D.; Nelan, E.

    2001-05-01

    The 3 Fine Guidance Sensors (FGS) - white-light shearing interferometers - are critical to the mission of the Hubble Space Telescope (HST) by providing highly accurate guiding for the observatory. Moreover, FGS1r in particular is a capable science instrument. Its two observing modes - Position Mode and Transfer Mode - support wide angle and narrow angle astrometry respectively. In Position Mode, a star's interferometric fringes are tracked to determine its angular position relative to other stars in the detector's field of view. Using this method, a star's parallax, proper motion, and reflex motion can be measured with a precision of about 1 mas per observation, while multi-epoch observing programs have yielded astrometry with accuracies approaching 0.2 mas for objects as bright as V=3 or as faint as V=16.5. Transfer Mode observations repeatedly scan an object's interferometric fringes to achieve sub-mas sampling of the fringe morphology with high signal-to-noise (conceptually analogous to imaging with a 1 mas pixel array). Post-observation analysis allows the measurement of angular separation, position angle and relative brightness of binary components, or a determination of the angular size of an extended object. Close binary systems with V < 12 can be detected down to 7 mas, while systems as faint as V=15 can be characterized to 12 mas, provided the magnitude difference between the components is less than about 2. (Wider systems with magnitude differences as large as 3.5 can be resolved.) Both FGS observing modes can be utilized to derive the total and fractional masses of binary systems, and thus the mass-luminosity relationship of the binary components. The FGS have also been used to observe and characterize non-point source objects, including Mira variables, asteroids, and active galactic nuclei, yielding information on the structure of these objects on scales as small as 8 mas. The FGS also function as 40 Hz photometers, offering milli-magnitude precision

  11. Cooperation between human cells sensitive to UVA radiations: a clue to the mechanism of cellular hypersensitivity associated with different clinical conditions

    SciTech Connect

    Francis, A.J.; Giannelli, F. )

    1991-07-01

    Six fibroblast strains sensitive to long wavelength ultraviolet radiation (UVA) and one control strain were used to see if cooperation between the different cell strains could modify the abnormally high yield of single-strand DNA breaks (SSB) in the sensitive strains caused by UVA irradiation in complete Dulbecco's MEM. The sensitive strains were established from individuals showing proneness to different types of light-induced skin damage (actinic reticuloid, familial actinic keratoses with internal malignancies, and unusual frequency of basal cell carcinomata). When sensitive and normal cells were cocultivated, the UVA-induced SSB decreased in the sensitive cells and increased in the normal ones by amounts proportional to the ratio of the two types of cells in the mixtures. Furthermore the regression of SSB, in the sensitive cells, on the proportion of normal cells in the mixture extrapolated to normal levels of SSB when the proportion of normal cells increased to one. Cocultivation of different sensitive cells did not reduce the UVA-induced SSB to levels below those of the less sensitive cell strains. From these results we conclude that substances, present in limiting amounts, even in normal cells, can be transferred from cell to cell, presumably by metabolic cooperation, and modify the yield of SSB caused by UVA radiation. The abnormal yields of SSB in the sensitive cells appear to be entirely attributable to deficits in the substances responsible for the intercellular cooperation. We suggest that such substances are small molecular weight scavengers of active oxygen species.

  12. 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.

  13. Treatment of progressive keratoconus by riboflavin-UVA-induced cross-linking of corneal collagen: ultrastructural analysis by Heidelberg Retinal Tomograph II in vivo confocal microscopy in humans.

    PubMed

    Mazzotta, Cosimo; Balestrazzi, Angelo; Traversi, Claudio; Baiocchi, Stefano; Caporossi, Tomaso; Tommasi, Cristina; Caporossi, Aldo

    2007-05-01

    To assess ultrastructural stromal modifications after riboflavin-UVA-induced cross-linking of corneal collagen in patients with progressive keratoconus. This was a second-phase prospective nonrandomized open study in 10 patients with progressive keratoconus treated by riboflavin-UVA-induced cross-linking of corneal collagen and assessed by means of Heidelberg Retinal Tomograph II Rostock Corneal Module (HRT II-RCM) in vivo confocal microscopy. The eye in the worst clinical condition was treated for each patient. Treatment under topical anesthesia included corneal deepithelization (9-mm diameter) and instillation of 0.1% riboflavin phosphate-20% dextran T 500 solution at 5 minutes before UVA irradiation and every 5 minutes for a total of 30 minutes. UVA irradiation was 7 mm in diameter. Patients were assessed by HRT II-RCM confocal microscopy in vivo at 1, 3, and 6 months after treatment. Rarefaction of keratocytes in the anterior and intermediate stroma, associated with stromal edema, was observed immediately after treatment. The observation at 3 months after the operation detected keratocyte repopulation in the central treated area, whereas the edema had disappeared. Cell density increased progressively over the postoperative period. At approximately 6 months, keratocyte repopulation was complete, accompanied by increased density of stromal fibers. No endothelial damage was observed at any time. Reduction in anterior and intermediate stromal keratocytes followed by gradual repopulation has been confirmed directly in vivo in humans by HRT II-RCM confocal microscopy after riboflavin-UVA-induced corneal collagen cross-linking.

  14. 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.

  15. Gene expression patterns associated with the biosynthesis of the sunscreen scytonemin in Nostoc punctiforme ATCC 29133 in response to UVA radiation.

    PubMed

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

    2009-07-01

    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 the 18-gene region are cotranscribed as part of a single transcriptional unit.

  16. 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

  17. 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.

  18. Effect of a Selective Mas Receptor Agonist in Cerebral Ischemia In Vitro and In Vivo.

    PubMed

    Lee, Seyoung; Evans, Megan A; Chu, Hannah X; Kim, Hyun Ah; Widdop, Robert E; Drummond, Grant R; Sobey, Christopher G

    2015-01-01

    Functional modulation of the non-AT1R arm of the renin-angiotensin system, such as via AT2R activation, is known to improve stroke outcome. However, the relevance of the Mas receptor, which along with the AT2R forms the protective arm of the renin-angiotensin system, as a target in stroke is unclear. Here we tested the efficacy of a selective MasR agonist, AVE0991, in in vitro and in vivo models of ischemic stroke. Primary cortical neurons were cultured from E15-17 mouse embryos for 7-9 d, subjected to glucose deprivation for 24 h alone or with test drugs, and percentage cell death was determined using trypan blue exclusion assay. Additionally, adult male mice were subjected to 1 h middle cerebral artery occlusion and were administered either vehicle or AVE0991 (20 mg/kg i.p.) at the commencement of 23 h reperfusion. Some animals were also treated with the MasR antagonist, A779 (80 mg/kg i.p.) 1 h prior to surgery. Twenty-four h after MCAo, neurological deficits, locomotor activity and motor coordination were assessed in vivo, and infarct and edema volumes estimated from brain sections. Following glucose deprivation, application of AVE0991 (10-8 M to 10-6 M) reduced neuronal cell death by ~60% (P<0.05), an effect prevented by the MasR antagonist. By contrast, AVE0991 administration in vivo had no effect on functional or histological outcomes at 24 h following stroke. These findings indicate that the classical MasR agonist, AVE0991, can directly protect neurons from injury following glucose-deprivation. However, this effect does not translate into an improved outcome in vivo when administered systemically following stroke.

  19. Effect of a Selective Mas Receptor Agonist in Cerebral Ischemia In Vitro and In Vivo

    PubMed Central

    Lee, Seyoung; Evans, Megan A.; Chu, Hannah X.; Kim, Hyun Ah; Widdop, Robert E.; Drummond, Grant R.; Sobey, Christopher G.

    2015-01-01

    Functional modulation of the non-AT1R arm of the renin-angiotensin system, such as via AT2R activation, is known to improve stroke outcome. However, the relevance of the Mas receptor, which along with the AT2R forms the protective arm of the renin-angiotensin system, as a target in stroke is unclear. Here we tested the efficacy of a selective MasR agonist, AVE0991, in in vitro and in vivo models of ischemic stroke. Primary cortical neurons were cultured from E15-17 mouse embryos for 7–9 d, subjected to glucose deprivation for 24 h alone or with test drugs, and percentage cell death was determined using trypan blue exclusion assay. Additionally, adult male mice were subjected to 1 h middle cerebral artery occlusion and were administered either vehicle or AVE0991 (20 mg/kg i.p.) at the commencement of 23 h reperfusion. Some animals were also treated with the MasR antagonist, A779 (80 mg/kg i.p.) 1 h prior to surgery. Twenty-four h after MCAo, neurological deficits, locomotor activity and motor coordination were assessed in vivo, and infarct and edema volumes estimated from brain sections. Following glucose deprivation, application of AVE0991 (10−8 M to 10−6 M) reduced neuronal cell death by ~60% (P<0.05), an effect prevented by the MasR antagonist. By contrast, AVE0991 administration in vivo had no effect on functional or histological outcomes at 24 h following stroke. These findings indicate that the classical MasR agonist, AVE0991, can directly protect neurons from injury following glucose-deprivation. However, this effect does not translate into an improved outcome in vivo when administered systemically following stroke. PMID:26540167

  20. Downregulation of the ACE2/Ang-(1-7)/Mas axis in transgenic mice overexpressing GH.

    PubMed

    Muñoz, Marina C; Burghi, Valeria; Miquet, Johanna G; Giani, Jorge F; Banegas, Ricardo D; Toblli, Jorge E; Fang, Yimin; Wang, Feiya; Bartke, Andrzej; Dominici, Fernando P

    2014-05-01

    The renin-angiotensin system (RAS) plays a crucial role in the regulation of physiological homeostasis and diseases such as hypertension, coronary artery disease, and chronic renal failure. In this cascade, the angiotensin-converting enzyme (ACE)/angiotensin II (Ang II)/AT1 receptor axis induces pathological effects, such as vasoconstriction, cell proliferation, and fibrosis, while the ACE2/Ang-(1-7)/Mas receptor axis is protective for end-organ damage. The altered function of the RAS could be a contributing factor to the cardiac and renal alterations induced by GH excess. To further explore this issue, we evaluated the consequences of chronic GH exposure on the in vivo levels of Ang II, Ang-(1-7), ACE, ACE2, and Mas receptor in the heart and the kidney of GH-transgenic mice (bovine GH (bGH) mice). At the age of 7-8 months, female bGH mice displayed increased systolic blood pressure (SBP), a high degree of both cardiac and renal fibrosis, as well as increased levels of markers of tubular and glomerular damage. Angiotensinogen abundance was increased in the liver and the heart of bGH mice, along with a concomitant increase in cardiac Ang II levels. Importantly, the levels of ACE2, Ang-(1-7), and Mas receptor were markedly decreased in both tissues. In addition, Ang-(1-7) administration reduced SBP to control values in GH-transgenic mice, indicating that the ACE2/Ang-(1-7)/Mas axis is involved in GH-mediated hypertension. The data indicate that the altered expression profile of the ACE2/Ang-(1-7)/Mas axis in the heart and the kidney of bGH mice could contribute to the increased incidence of hypertension, cardiovascular, and renal alterations observed in these animals.

  1. Radiation induced primary processes of aqueous 8-methoxy-psoralen. A pulse radiolysis study

    NASA Astrophysics Data System (ADS)

    Solar, S.; Quint, R.

    The spectroscopic characteristics as well as the formation and decay kinetics of the 8-MOP radical cation (8-MOP .+), radical anion (8-MOP .-), H-adduct (8-MOP.H) and OH-adduct (8-MOP.OH) are presented.

  2. Indoxyl sulfate downregulates expression of Mas receptor via OAT3/AhR/Stat3 pathway in proximal tubular cells.

    PubMed

    Ng, Hwee-Yeong; Yisireyili, Maimaiti; Saito, Shinichi; Lee, Chien-Te; Adelibieke, Yelixiati; Nishijima, Fuyuhiko; Niwa, Toshimitsu

    2014-01-01

    Renin-angiotensin system (RAS) plays a pivotal role in chronic kidney disease (CKD). Angiotensin converting enzyme-related carboxypeptidase 2 (ACE2)/angiotensin (Ang)-(1-7)/Mas receptor axis counteracts the deleterious actions of Ang II. ACE2 exerts its actions by cleaving Ang II into Ang-(1-7) which activates Mas receptor. This study aimed to determine if the expression of Mas receptor is altered in the kidneys of CKD rats, and if indoxyl sulfate (IS), a uremic toxin, affects the expression of Mas receptor in rat kidneys and cultured human proximal tubular cells (HK-2 cells). The expression of Mas