Disease relevance of Light

• Pretreatment of mice with HPD photoradiation resulted in 50% suppression of contact hypersensitivity to DNFB [1].
• A comparison study of the effects of hematoporphyrin derivative (HPD) photoradiation therapy on two different mouse sarcoma tumor model systems (RIF-1 + EMT-6) was performed [2].
• Photosensitization with anticancer agents. 20--EPR studies on the photodynamic action of phleichrome: formation of semiquinone radical and activated oxygen species on illumination with visible light [3].
• Escherichia coli Phe-tRNA, modified with the photoaffinity reagent 6-(2-nitro-4-azidophenylamino)caproate on the 3-(3-amino-3-carboxypropyl)uridine residue, was crosslinked to E. coli EFTu Section upon irradiation at 0 degree C with visible light at wavelengths greater than 400 nm [4].
• In vivo phosphorus-31 magnetic resonance (MR) spectra were obtained by a surface coil method from rat glioma tissue inoculated subcutaneously in CD Fisher rats, and the effects of photoradiation therapy on tumors were evaluated by sequentially observing spectral changes [5].

High impact information on Light

• Films and powders of TiO(2-x)N(x) have revealed an improvement over titanium dioxide (TiO2) under visible light (wavelength < 500 nanometers) in optical absorption and photocatalytic activity such as photodegradations of methylene blue and gaseous acetaldehyde and hydrophilicity of the film surface [6].
• Sequence homology and mutational analysis suggest that D. radiodurans bacteriophytochrome functions as a light-regulated histidine kinase, which helps protect the bacterium from visible light [7].
• The metallointercalator Rh(phi)2DMB3+ (phi, 9,10-phenanthrenequinone diimine; DMB, 4,4'-dimethyl-2,2'-bipyridine) catalyzed the repair of a thymine dimer incorporated site-specifically in a 16-base pair DNA duplex by means of visible light [8].
• Irradiation of tissues with visible light in the presence of ANAPP3 resulted in an irreversible antagonism, which was prevented when adenosine triphosphate was present [9].
• Photoradiation, with the use of hematoporphyrin derivative (Hpd) activated by visible light in the red region of the spectrum, was an effective treatment for controlling local and regional chest wall recurrences of breast carcinoma [10].

Chemical compound and disease context of Light

• Photosensitization with anticancer agents 19. EPR studies of photodynamic action of calphostin C: formation of semiquinone radical and activated oxygen on illumination with visible light [11].
• Efficient photoinduced conversion of an azo dye on hexachloroplatinate(IV)-modified TiO2 surfaces under visible light irradiation-A photosensitization pathway [12].
• DNA used as a substrate was modified either by exposure to ionizing radiation or by photosensitization using visible light in the presence of methylene blue (MB) [13].
• The use of topical aminolevulinic acid (ALA) and blue light for nonhypertrophic actinic keratoses currently represents the only approved dermatologic application for PDT in the U.S.A. ALA is a photosensitizer precursor that is metabolized by cells into protoporphyrin IX (PpIX), which can be subsequently activated by visible light [14].
• Second, although treatment of mice with rose bengal and visible radiation suppresses contact hypersensitivity while treatment with eosin and visible radiation does not, both types of phototoxic treatment suppressed the GVH reaction [15].

Biological context of Light

• Phototransformation of green fluorescent protein with UV and visible light leads to decarboxylation of glutamate 222 [16].
• The effect of intense visible light (light damage) on the expression of heme oxygenase 1 (HO-1), a protein induced by oxidative stress, was investigated in the rat retina [17].
• The effects of hematoporphyrin derivative plus photoradiation were examined in the presence of oligomycin, an inhibitor of mitochondrial oxidative phosphorylation, or iodoacetate, an inhibitor of glycolysis, experiments designed to elucidate the site of action leading to reduced ATP levels [18].
• Correlations between histological and kinetic bone formation indices were better when better when based on the extent of double tetracycline labels than on measurements of osteoid by visible light microscopy [19].
• Ultimately, the energy of visible light is converted to reducing equivalents for plastocyanin and cytochrome c. The sequential electron transfer described here resembles the events in a rudimentary electron-transport chain [20].

Anatomical context of Light

• In this study, we evaluated the capacity of 4,5-dibromorhodamine methyl ester (TH9402), a photosensitizer structurally similar to rhodamine, a dye transported by Pgp, and which becomes highly cytotoxic on activation with visible light to selectively deplete alloreactive T lymphocytes [21].
• After photoradiation of cells with white light, both DHE and MC-540 showed high cytocidal activity toward lymphoid and myeloid neoplastic cells but had a significantly lesser effect on normal granulocyte-macrophage (CFU-GM), erythroid (BFU-E), and mixed colony-forming (CFU-GEMM) progenitor cells [22].
• Hematoporphyrin derivative (HPD) plus photoradiation caused the inactivation of DNA polymerases from calf thymus and R3230AC rat mammary tumor [23].
• We determined that incubation of human skin fibroblasts with 20 microM aloe emodin for 18 h followed by irradiation with UV or visible light resulted in significant photocytotoxicity [24].
• Fullerene C60 dissolved in polyvinylpyrrolidone was mutagenic for Salmonella strains TA102, TA104 and YG3003 in the presence of rat liver microsomes when it was irradiated by visible light [25].

Associations of Light with chemical compounds

• Visible-light photocatalysis in nitrogen-doped titanium oxides [6].
• The intrinsic resistance is associated with differences in the affinity of beta-lactams for penicillin-binding proteins, but intrinsic resistance is probably more complex, because the pH of the medium, chelating agents, visible light, and temperature also effect its expression [26].
• DNA photolyase is a pyrimidine-dimer repair enzyme that uses visible light [27].
• The process involves brief photolysis of tris-bipyridylruthenium(II) dication with visible light in the presence of the electron acceptor ammonium persulfate and the proteins of interest [28].
• Carbon monoxide bound to iron or copper in substrate-reduced mitochondrial cytochrome c oxidase (ferrocytochrome c:oxygen oxidoreductase, EC 1.9.3.1) from beef heart has been used to explore the structural interaction of the a3 heme-copper pocket at 15 K and 80 K in the dark and in the presence of visible light [29].

Gene context of Light

• Importantly, ppk25 mutant males that show no response to females in the dark execute all of the normal steps of courtship behavior in the presence of visible light, suggesting that ppk25 is required for activation of courtship behavior by chemosensory perception of female pheromones [30].
• UVR2 and UVR3 products were previously identified as photolyases that remove UV-induced pyrimidine dimers in the presence of visible light [31].
• The catalytic activity of the recombinant wild-type IVD was the highest in the presence of isovaleryl-CoA, and its UV/visible light spectrum in the presence of isovaleryl-CoA showed quenching of its characteristic absorption in the 445-nm region and appearance of absorption at 600 nm [32].
• This partial impairment of the cutaneous antioxidant defense system by near ultraviolet/visible light, showing that the most susceptible component in skin is catalase, suggests possible pharmacological interventions [33].
• METHODS: Wildtype and c-fos-/- mice were exposed to low (roomlight) or high levels of visible light for up to two hours [34].

Analytical, diagnostic and therapeutic context of Light

• Photodynamic therapy, which consists of treatment with hematoporphyrin derivative (HPD) followed by photoradiation with visible light, is a promising approach to treatment of various cancers [35].
• Spin-trapping studies of incubations containing DCF, 5,5-dimethyl-1-pyrroline N-oxide (DMPO) and either reduced glutathione (GSH) or reduced NADH demonstrate, under irradiation with visible light, the production of the superoxide dismutase-sensitive DMPO/*OOH adduct [36].
• (1) An accurate and sensitive separation method by high-pressure liquid chromatography for photoproducts of bilirubin under anaerobic irradiation of visible light is described [37].
• When aged 2, 4, 8, and 12 months, some rats were given the synthetic antioxidant dimethylthiourea (DMTU) by intraperitoneal injection and were exposed to intense visible light for as long as 24 hours [38].
• With the use of HPLC methodology, plasma concentrations of alpha-carotene, beta-carotene and beta-cryptoxanthin were determined with UV/visible light detection for plasma and electrochemical detection for cervical tissue [39].

References