Interaction Of Ultraviolet Radiation Research Articles

Photodistributed eruptive telangiectasias: an uncommon adverse drug reaction. A retrospective case series.

Drug-induced photodistributed telangiectasia (PT) is a cutaneous adverse effect (AE) resulting from the interaction of ultraviolet radiation with pharmacotherapy. Reports of PT in the literature are scarce. We report 25 cases of drug-induced PT highlighting the potential relationship between the onset of skin lesions, drug intake and photo exposure. We alert practitioners that PT is a possible dermatological phototoxic AE of many drugs.

Appropriate Technologies to Accompany Sunscreens in the Battle Against Ultraviolet, Superoxide, and Singlet Oxygen.

The interaction of ultraviolet radiation with biological matter results in direct damage such as pyrimidine dimers in DNA. It also results in indirect damage provoked by the production of reactive oxygen species (ROS) catalyzed by photosensitizers. Photosensitizers can be endogenous (e.g., tryptophan) or exogenous (e.g., TiO2 and other photostable UVA sunscreens). Direct damage triggers an inflammatory response and the oxidative and proteolytic bursts that characterize its onset. The inflammatory reaction multiplies the effects of one single photon. Indirect damage, such as the peroxidative cascade in membrane lipids, can extend to thousands of molecular modifications per absorbed photon. Sunscreens should therefore be formulated in the presence of appropriate antioxidants. Superoxide and singlet oxygen are the main ROS that need to be tackled: this review describes some of the molecular, biochemical, cellular, and clinical consequences of exposure to UV radiation as well as some results associated with scavengers and quenchers of superoxide and singlet oxygen, as well as with inhibitors of singlet oxygen production.

Phototoxicology and photocarcinogenesis at the U.S. Food and Drug Administration's National Center for Toxicological Research

Ultraviolet radiation (UVR) causes skin cancer in humans and can induce skin cancer in test animals. The interaction of UVR with many drugs has been reported, however, there is a paucity of data concerning the carcinogenesis of cosmetic ingredients and environmental contaminants in combination with UVR. A research center has been developed at the U.S. Food and Drug Administration's National Center for Toxicological Research to quantify the potential carcinogenicity of combined exposure to chemicals and UVR. The chemicals tested in this facility are nominated to, and approved by, the National Toxicology Program. In this paper we describe the nomination of chemicals, test animals, source of UVR, dosimetry, and test paradigm that are used. This unique test facility is being used to protect public health through quantifying the photocarcinogenicity of chemicals to which the public is exposed.

Natural levels of hydrogen peroxide (H2O2) in deep clear South temperate lakes: Field and laboratory evidence of photo- and biotic production

Hydrogen peroxide (H2O2) is a ubiquitous reactive oxygen species (ROS) in aquatic systems and is produced mainly in surface water by the interaction of ultraviolet radiation (UVR) and natural dissolved organic carbon (DOC). Andean Patagonian lakes are ultraoligotrophic, clear systems with extended photic zones (~40 m), and are exposed to challenging UVR levels due to their lati-altitudinal situation and extremely low DOC levels. This investigation describes the seasonal levels of H2O2 in relation to DOC quality in the water column of lakes Moreno East (ME) and Moreno West (MW), two deep (ca. 100 m), ultraoligotrophic, low-DOC (<0.7 mg L−1) systems of Andean Patagonia. H2O2 concentrations recorded in the lakes were below 60 nM, ranging from ~3 to ~60 nM in Lake ME and from ~5 to ~35 nM in Lake MW. In most of the samples of both lakes, the H2O2 levels were higher in the photic zone (surface to 30–40 m) than the aphotic zone (from 30–40 m to 90–100 m), particularly in summer samples. Laboratory experiments evaluated the abiotic (photochemical) and biotic (microbial) production of H2O2 in seasonal (summer, autumn) samples which varied DOM quality due to lake (ME, MW) and depth (photic and aphotic lake layers) provenance. Abiotic and biotic production of H2O2 attained higher levels in summer samples from the photic zones of both lakes. Humic DOM from deep layers (particularly from summer samples) was more susceptible to both photo- and bio-degradation than DOM from upper lake layers, which was characterized by stronger signs of degradation and progress in diagenesis.

Attenuation of Ultraviolet Radiation in Rocks and Minerals: Implications for Mars Science

AbstractThe effects of radiation on the survivability of key biosignatures are a driving factor in exploration strategies throughout the solar system. Ultraviolet (UV) radiation, especially shorter wavelength UVC radiation, is known to be damaging to organisms and to potential organic biosignatures; however, the interaction of UV radiation with minerals and rocks is not well understood. Constraining the survivability of organics and generation of habitable zones requires assessment of physical parameters such as penetration depth of UV photons. This type of information helps to identify to what extent rocks and minerals can provide effective shielding against UV radiation and is especially important on Mars, where the surface chemistry is more oxidizing, and the radiation environment is more extreme than on Earth. Using pressed pellets of natural gypsum, kaolinite, Mars simulant basalt, and welded tuff, we measured the spectral transmittance of each in the wavelength range of 220–400 nm. Although transmittance drops off quickly with depth, detectable levels of UV can penetrate &gt;500 μm in each material. Each substrate allowed higher transmittance of UVC radiation than of longer wavelength UVA/B radiation, possibly as a result of surface reflectance and internal scattering properties. This could result in increased subsurface photolysis of organic compounds and biosignatures. We have used the transmittance data collected herein to constrain the lifetimes of several organic molecules in the Martian subsurface. These results will also have implications for organic analyses to be conducted by Mars 2020 and could be used to better constrain the SHERLOC/Mars 2020 interrogation volume.

Color variation of electrophoretic styrene-acrylic paints under field and accelerated ultraviolet exposure

Metals are mostly painted to improve corrosion protection of the coated item. Nevertheless, paints can be used to deliver visual aspects to them. Several investigations were conducted to comprehend color variation of paints as function of accelerated tests however, limited information is found concerning these variations versus field exposure. Thus, there is the interest to cover this lack of information and investigate color changes of waterborne paints versus field exposure. In this study colored styrene-acrylic painted steel panels were naturally aged in the alpine climate of Trento, northern of Italy. Color measurements were conducted according to the CIEL*a*b* standard. Gloss measurements and FT-IR spectroscopy assessed variations on the surface topography and chemical structure of the coated panels. It was observed that the changes in color of the colored paints were commanded by the interaction of ultraviolet radiation and they were dependent on the chemical nature of the color pigments. In addition, in the months with attenuated solar irradiance and predominance of TOWISO conditions, gloss reduction rates and L* of the coated panels have their evolution trend shifted. Upon accelerated UV.B ageing conducted in dry condition neither fluctuations on the L* nor attenuation on the gloss reduction rates were detected.

Abstract 4167: Ultraviolet radiation cooperates with individual oncogenes to drive melanomagenesis through distinct molecular mechanisms

Abstract The contribution ultraviolet radiation (UVR) makes to genetically distinct melanoma subtypes is unclear. Melanoma driven by oncogenic BRAF or oncogenic NRAS differ in their epidemiological, clinicopathological and genetic features. NRAS melanoma in humans occurs in older individuals and presents at sites most exposed to UVR damage such as the head and neck. In this study we show excessive sun exposure and NRAS-driven melanoma can co-occur by juxtaposing the epidemiological, clinical and genetic characteristics of a G12DNRAS-driven human melanoma case subject to extreme UVR exposure. To model the interaction of UVR with specific oncogenes and mimic human disease, we used mouse melanoma models driven by V600EBRAF or G12DNRAS. We previously reported that UVR cooperates with V600EBRAF by targeting the tumour suppressor TP53. In this study we confirm that UVR cooperates with G12DNRAS to drive melanoma and, as observed in humans, murine UVR-G12DNRAS melanoma occurs in older animals that accumulate higher lifetime exposure to UVR. Furthermore, we find murine UVR-G12DNRAS melanomas are histologically and genetically heterogeneous, and distinct to UVR-V600EBRAF murine and human melanomas. UVR-G12DNRAS melanomas present more UVR-induced mutations, a longer latency to tumour development and secondary driver mutations distinct from UVR-V600EBRAF melanoma. We investigated whether UVR cooperates equally with other RAS isoforms, and exposed G12DKRAS animals to UVR. These animals presented a different latency to melanoma development and specific cooperating secondary targets distinct from UVR-V600EBRAF and UVR- G12DNRAS. This implies that different RAS isoforms activate oncogenic pathways differently. Critically, UVR-V600EBRAF, UVR-G12DNRAS, UVR-G12DKRAS tumors present similar mutation rates when UVR exposure is held constant, which suggests that the differences in tumour latency might be explained if melanomas driven by different oncogenes require varying numbers of subsequent co-operators. Finally, we present preclinical evidence showing how targeting the UVR-induced mutations found in the “long tail” of UVR-related mutations in NRAS melanoma can provide therapeutic options for NRAS mutant melanoma patients. The insight gained begins to provide a molecular explanation for distinct associations between UVR and individual oncogenes in melanomagenesis, and we show how UVR-induced damage can be exploited to stratify patients for personalised therapy approaches. Citation Format: Amaya Viros, Malin Pedersen, Simon J. Furney, Maria Romina Girotti, Grazia Saturno, Elena Galvani, Berta Sanchez-Laorden, Kate Hogan, Charlotte Ng, Jorge S. Reis-Filho, Paul Lorigan, Martin Cook, Richard Marais. Ultraviolet radiation cooperates with individual oncogenes to drive melanomagenesis through distinct molecular mechanisms. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 4167.

Drug-induced photoallergic and phototoxic reactions

Drug-induced photosensitivity involves reactions to medication triggered by exposure of the skin to ultraviolet light. Medications that trigger reactions can be topical or oral. Following interaction of ultraviolet radiation with a chemical present in sufficient amounts in the skin, one of the several reactions may occur in susceptible patients, most commonly photoallergy or phototoxicity. These reactions can be diagnosed separately based on pathogenesis, clinical characteristics and histopathology. Phototoxic disorders have a higher incidence than photoallergic disorders. The action spectra for most photoallergens and phototoxins lie in the ultraviolet A range. Subtypes of drug-induced photosensitivity include dyschromia, pseudoporphyria, photo onycholysis, and lichenoid and telangiectatic reactions.

Vertical distribution of Daphnia longispina in a shallow subarctic pond: Does the interaction of ultraviolet radiation and Chaoborus predation explain the pattern?

The adaptive significance of vertical migration by planktonic organisms is often explained in terms of reducing the risk of predation. Observational evidence, however, indicates that migratory patterns may also be triggered by solar ultraviolet (UV) radiation. Such a strategy would allow animals to escape from UV-induced damage into deeper water layers. In this study, we examine the relation of several biotic (invertebrate predators, algae) and abiotic (temperature, radiation) factors to the vertical distribution of Daphnia longispina in a 50-cm-deep, fishless pond in subarctic Finnish Lapland. Samples were taken from three depths, on both sunny and overcast days, and at different hours of day. Our results show that, on sunny days, the vertical distribution of Daphnia responds to ultraviolet radiation, whereas on overcast days, predator avoidance (phantom midge, Chaoborus obscuripes) is a better predictor of Daphnia distribution. Juvenile and adult Daphnia showed a similar distribution pattern.

Hydrogen peroxide formation: The interaction of ultraviolet radiation and dissolved organic carbon in lake waters along a 43–75°N gradient

Hydrogen peroxide (H2O2) formation rates (nM h−1), photoproductive capacity (nM W−1 h−1 m−2), and H2O2 formation efficiency (ϕH2O2) were measured on water samples exposed to a standard light source with a spectral composition similar to natural sunlight. Samples were from lakes and wetlands with varying levels of dissolved organic C (DOC), P, Fe, Ca, and pH. The relationship between H2O2 formation rates and DOC was a power function (H2O2 = 49.65 DOC1.71; r2 = 0.94), whereas the relationships between formation rates and DOC fluorescence (DOCFL) (H2O2 = 118.32 + 33.06 DOCFL; r2 = 0.98) and absorption coefficients at 310 (Ka310) were linear (H2O2 = 185.0 + 55.50 Ka310; r2 = 0.91). ϕH2O2 was independent of DOC (r2 = 0.12). Apparent quantum yields decreased with increasing wavelengths (300–400 nm). However, when apparent quantum yields were corrected with solar irradiance data, values were greatest in the UV‐A (320–400 nm) region. The patterns observed were consistent for samples from temperate to arctic regions.

Interactions of ultraviolet radiation, 12- O-tetradecanoyl-phorbol-13-acetate and retinoic acid in the skin of hairless mice

Epidermal changes (mitosis, DNA synthesis, hyperplasia and acanthosis) were used to assay the effects of three different treatments on the dorsal skin of hairless mice: ultraviolet radiation (UVR), all- trans retinoic acid (RA) and/or 12- O-tetradecanoyl-phorbol-13-acetate (TPA). Mice receiving 20 exposures to fluorescent sunlamps in 4 wk (200 Robertson-Berger counts, or about one erythema dose daily, 5 days/wk) and subsequent topical application of methanol (3 applications/wk, beginning 3 wk after the end of UVR treatment) still displayed hyperproliferative cellular activity at least 17 wk after the final UV irradiation. Alone, either RA or TPA (0.001% in methanol, applied topically 3 times/wk) had similar hyperproliferative effects on the epidermis initially, but the skin appeared to adapt to continued treatment with TPA after 14 wk while RA-treated skin remained hyperproliferative. To study the effects of each reagent on UVR-exposed skin, an initiation-promotion protocol was used: repeated applications of the test compound were started 3 wk after the end of 4 wk of UVR exposures. By this method, treatment with either TPA or RA resulted in additional epidermal activity initially. However, although TPA-treated epidermis returned to the control level of activity by wk 21, no significant adaptation to RA treatment was seen.

Quantum efficiency of flourescence excited by photodissociation in metal halide vapors and applications

Interaction of ultraviolet radiation with diatomic and triatomic metal halide vapors is discussed. Patterns observed in ultraviolet absorption cross sections are noted. Measurements of quantum efficiency of fluorescence excited by photodissociation (QE = fluorescence photons out/ultraviolet photons in) are described. Results and their implications for 205 ± 15-nm deuterium, 213.9-nm-Zn resonance and deuterium VUV excitation are discussed. Applications of photodissociation in photodissociation lasers, electric discharge lamps, and collisional processes such as measurement of reactive and quenching cross sections are summarized.

The effect of ultraviolet radiation on the electrical conductivity of human bone.

The electrical conductivity of intact bone, collagen and apatite mineral was determined in the region of moderately high fields. After exposure to ultraviolet (UV) radiation the conductivity of the specimens was redetermined. Following exposure marked decreases in electrical conductivity occurred in all specimens. The possible modes of interaction of UV radiation with bone are discussed. It is suggested that protonic conduction may be an important mode of charge transport in bone.

Interaction of ultra-violet radiation with surface energy levels of the ZnO-Li2O-O2system as revealed by electron spin resonance spectroscopy

E.s.r. examination of the influence of u.v.-irradiation on surface processes at Li-doped ZnO shows that several paramagnetic centres are involved in the interaction with the gas phase. Annealing in oxygen at 773 K results in formation of zinc vacancies, with signal at g= 2.0130. On oxygen adsorption at 293 K, zinc vacancies are formed at the surface with g= 2.0145. Both signals are visible only in Li-doped samples of low Fermi-level, their intensity depending on irradiation. The radical oxygen signals at g1= 2.054, g2= 2.0077 and g3= 2.0033 accompany the formation of vacancies and increase on irradiation due to photo-adsorption. Signals at g= 1.96 and 1.975 are also present. On grinding, F-centres are formed with g= 1.997. They reversibly adsorb oxygen and interact with radiation. X-ray photoelectron spectra reveal two kinds of oxygen, the lattice oxygen 1 s level depending on defect structure.

Ultraviolet radiation and nucleic acid.

Recent studies on the interaction of ultraviolet radiation and molecules of desoxyribonucleic acid (DNA) are reviewed. Evidence is presented that ultraviolet can change DNA in specific ways and can partially reverse these changes. Both forward and backward alterations have been demonstrated in DNA function. Evidence is presented that much of the damage that ultraviolet radiation inflicts on cells and viruses is caused directly by its effects on DNA. Reaction mechanisms involved are discussed. (C.H.)