bluuebunny/crossref_metadata_2025_split huggingface dataset:
Light Quality Influences Indigo Precursors Production and Seed Germination in Isatis tinctoria L. and Isatis indigotica Fort.¶
Authors: Tozzi Sabrina , Lercari Bartolomeo , Angelini Luciana G. 
Published: July 2010

ABSTRACT Isatis tinctoria L. and Isatis indigotica Fort. are biennial herbaceous plants belonging to the family of Cruciferae that are used as a source of natural indigo and show several morphological and genetic differences. Production of indigo (indigotin) precursors, indican (indoxyl β‐D glucoside) and isatan B (indoxyl ketogluconate), together with seed germination ability were compared in Isatis tinctoria and Isatis indigotica grown under six different light conditions (darkness, white, red, far red, blue, yellow light) at 25°C. Light quality influenced both germination and production of indigo precursors in the two Isatis species. Different responsiveness to far red and blue light was observed. Indeed, a detrimental effect on germination by blue and far red light was found in I. tinctoria only. Different amounts of isatan B were produced under red and far red light in the two Isatis species. In I. tinctoria, the level of main indigo precursor isatan B was maximal under red light and minimal under far red light. Whereas in I. indigotica far red light promoted a large accumulation of isatan B. The photon fluence rate dependency for white and yellow light responses showed that the accumulation of indigo precursors was differently influenced in the two Isatis species. In particular, both white and yellow light enhanced above 40 μmol m−2s−1 the production of isatan B in I. indigotica while only white light showed a photon fluence dependency in I. tinctoria. These results suggest a different role played by the labile and stable phytochrome species (phyA and phyB) in the isatan B production in I. tinctoria and I. indigotica. I. indigotica, whose germination percentage was not influenced by light quality, demonstrated higher germination capability compared with I. tinctoria. In fact, I. tinctoria showed high frequency of germination in darkness and under light sources that establish high phytochrome photoequilibrium (red, white and yellow light). Germination in I. tinctoria was negatively affected by far red and blue light. I. indigotica seeds appear to be indifferent to canopy‐like light (far red). Our results provide further insights on the distinct behaviour of I. tinctoria and I. indigotica that belong to two different genetic clusters and different original environments.
14‐Fluoro‐Bacteriorhodopsin Gelation Films for Dynamic Holography Recording¶
Authors: Korchemskaya Elena , Burykin Nikolai , de Lera Angel , Alvarez Rosana , Pirutin Sergey , Druzhko Anna 
Published: July 2010

ABSTRACTThe first dynamic holography recording using 14‐fluoro‐(14‐F) bacteriorhodopsin (BR) gelatin films has been achieved. 14‐F BR is an artifical BR pigment made by reconstitution of bacterioopsin (native BR without chromophore) with synthetic 14‐F ratinal. Low‐intensity red light from a cw HE‐Ne laser was used for dynamic holography recording on the 14‐F wild type (WT) BR and 14‐F D96N mutant BR in gelatin films. There is not true comparing the diffraction efficiency for 14‐F D96N BR and 14‐F WT gelatin film, unlike the increase diffraction efficiency for D96N BR gelation film with native chromphore relative to the WT BR gelatin film with native chromophore. Pre‐illumination with blue light of the 14‐F BR gelatin films significantly increases the differaction effciency of both the the 14‐F WT and the 14‐F D96N BR pigments. The sequential application of blue and red laser beams indicates that 14‐F WT and the 14‐F D96N BR pigments. The sequential application of blue and red laser beams indicates taht 14‐F BR gelation films can be useful for optical memory.
Sun‐reactive Skin Type in 4912 French Adults Participating in the SU.VI.MAX Study¶
Authors: Guinot Christiane , Malvy Denis J.‐M. , Latreille Julie , Ezzedine Khaled , Galan Pilar , Tenenhaus Michel , Ambroisine Laurence , Hercberg Serge , Tschachler Erwin 
Published: July 2010

ABSTRACTPhototype classifications were initially developed in an attempt to predict the skin reactions of patients to phototherapy and are now widely used to advise individuals with regard to sun protection. A transversal study was conducted on the SU.VI.MAX cohort to estimate the frequency of sunreactive skin features in a large, general adult population‐based sample, and to describe the associations between these features. The data were collected 3 years after the beginning of the SU.VI.MAX nutritional intervention study on 4912 volunteers (2868 women aged 35–60 years and 2044 men aged 45–60 years). A multiple correspondence analysis was performed to study the associations between the features. The results showed that these features correspond to a one‐dimensional phenomenon, which allowed us to establish a score to summarize skin sensitivity to sun exposure. Furthermore, we found a link between gender and phototype using the Césarini classification (phototype IV: 37% of women, 47% of men). The analysis of the relationship with sun‐reactive skin features and the score revealed the same trend. Phenotypic evaluation appears to be a good estimator of skin sensitivity to sun exposure for clinical screening or for use in research, and is easy to collect at a lower cost. Moreover, the sun sensitivity difference between gender should be considered in education about photoprotection.
Protein Kinase C Epsilon Signals Ultraviolet Light‐induced Cutaneous Damage and Development of Squamous Cell Carcinoma Possibly Through Induction of Specific Cytokines in a Paracrine Mechanism¶
Authors: Wheeler D. L. , Li Y. , Verma Ajit K. 
Published: July 2010

ABSTRACTProtein kinase C (PKC), a family of phospholipid‐dependent serine/threonine kinases, is not only the major intracellular receptor for the mouse skin tumor promoter 12‐O‐tetradecanoylphorbol‐13‐acetate (TPA) but also is activated by a variety of stress factors including ultraviolet radiation (UVR). PKCɛ is among six isoforms (α, δ, ɛ, η, μ and ζ) expressed in the mouse skin. To determine the in vivo functional specificity of PKCɛ in mouse skin carcinogenesis, we generated PKCɛ transgenic mouse (FVB/N) lines 224 and 215 that overexpress PKCɛ protein approximately 8‐ and 18‐fold, respectively, over endogenous levels in the basal epidermal cells and cells of the hair follicle. PKCɛ transgenic mice were observed to be highly sensitive to the development of papilloma‐independent metastatic squamous cell carcinoma (mSCC) elicited either by repeated exposure to UVR or by the 7,12‐Dimethylbenzanthracene–TPA tumor promotion protocol. The development of squamous cell carcinoma (SCC) appears to be linked to the PKCɛ‐mediated induction of cytokine tumor necrosis factor–α(TNFα). Immunohistochemical analysis for the expression of PKCɛ in the SCC of PKCɛ transgenic mice revealed that PKCɛ was not expressed in the tumor itself; however, the uninvolved tissue surrounding the SCC exhibited intense PKCɛ expression. Also, human SCC, similar to mouse SCC, did not express PKCɛ in the tumor, whereas the surrounding uninvolved epidermis revealed strong PKCɛ expression. These findings in both the PKCɛ mouse model and human SCC indicate that overexpression of PKCɛ in epidermis may lead to a microenvironment, which is suitable for enhancing the development of mSCC by a paracrine mechanism involving specific cytokines including TNFα.
Reconstruction of DNA Repair–deficient Xeroderma Pigmentosum Skin In Vitro: A Model to Study Hypersensitivity to UV Light¶
Authors: Bernerd Françoise , Asselineau Daniel , Frechet Mathilde , Sarasin Alain , Magnaldo Thierry 
Published: July 2010

ABSTRACTXeroderma pigmentosum (XP) is a rare, recessive, photosensitive and cancer‐prone syndrome, the biochemical hallmark of which is a defect in nucleotide excision repair of ultraviolet (UV)–induced mutagenic lesions. After isolation and amplification of several strains of XP‐C keratinocytes and fibroblasts, a three‐dimensional skin model in vitro comprising both epidermis and a dermal equivalent could be obtained. XP dermal tissues and XP epidermis displayed specific morphological and biochemical characteristics compared with tissues obtained with normal cells. One of the major features was the formation of epidermal invaginations into the dermal equivalent. After UV‐B exposure, and contrary to repair of DNA lesions in normal cells, the XP model displayed repair deficiency with long‐lasting persistence of UV‐induced DNA damage and p53 positive nuclei. Recent data obtained after genetic correction leading to functional XPC gene in keratinocytes and fibroblasts revealed that several abnormal features could be normalized. In conclusion, reconstruction of XP skin in vitro provides a very promising system to study genetic hyperphotosensitivity and opens a rational perspective to XP tissue therapy.
Assessment of Cutaneous Photosensitivity of TOOKAD (WST09) in Preclinical Animal Models and in Patients¶
Authors: Weersink Robert A. , Forbes Jason , Bisland Stuart , Trachtenberg John , Elhilali Mostafa , Brún Pierre H. , Wilson Brian C. 
Published: July 2010

ABSTRACTTOOKAD (WST09) is a new, long‐wavelength palladium bacteriopheophorbide photosensitizer that targets tissue vasculature. The cutaneous phototoxicity of TOOKAD was assessed in normal rat and pig animal models and in patients in a Phase‐I trial of TOOKAD‐mediated photodynamic therapy (PDT) for recurrent prostate cancer. Controlled skin exposures were administered using solar‐simulated light at various times after drug administration. Two different spectral ranges were used. In the first, the UV portion of the spectrum was removed (UV−) because UV irradiation in nondrugged control animals produced an erythema response at incident energy densities (J/cm2) lower than those required to induce a PDT response. In the second, the full solar spectrum (UV+) was used, and the potentiation by the photosensitizer of the UV‐mediated minimum erythema dose was assessed. Results showed that the PDT skin response was negligible at clinical drug doses of 2 mg/kg for any period after administration at light doses of 128 J/cm2 in the animal models. In patients, there was no observed UV− skin response at doses of up to 2 mg/kg, drug–light intervals of 1–3 h or greater and light exposures up to 128 J/cm2. At higher drug doses in the rat and pig models, the duration of skin phototoxicity was found to be ∼3 h and less than 1 h, respectively. Using the full spectrum of solar‐simulated light, the presence of TOOKAD did not measurably enhance the UV+‐induced erythema in the rats, pigs or patients.
Multiplex Polymerase Chain Reaction Analysis of UV‐A– and UV‐B–induced Delayed and Early Mutations in V79 Chinese Hamster Cells¶
Authors: Dahle Jostein , Noordhuis Paul , Stokke Trond , Svendsrud Debbie Hege , Kvam Egil 
Published: July 2010

ABSTRACTWe previously reported that approximately 10% of V79 Chinese hamster fibroblast populations clonally derived from single cells immediately after irradiation with either ultraviolet B (UV‐B, 290–320 nm, mainly 311 nm) or ultraviolet A (UV‐A, 320–400 nm, mainly 350–390 nm) radiation exhibit genomic instability. The instability is revealed by relatively high mutation frequencies in the hypoxanthine phosphoribosyl transferase (hprt) gene up to 23 cell generations after irradiation. These delayed mutant clones exhibited higher levels of oxidative stress than normal cells. Therefore, persistently increased oxidative stress has been proposed as a mechanism for UV‐induced genomic instability. This study investigates whether this mechanism is reflected in the deletion spectrum of delayed mutant clones. Eighty‐eight percent of the delayed mutant clones derived from UV‐A–irradiated populations were found to have total deletion of the hprt gene. Correspondingly, 81% of UV‐A–induced early mutations (i.e. detected shortly after irradiation) also had total deletions. Among delayed UV‐B–induced mutant clones, 23% had total deletions and 8% had deletion of one exon, whereas all early UV‐B events were either point mutations or small deletions or insertions. In conclusion, the multiplex polymerase chain reaction deletion screen showed that there were explicit differences in the occurrence of large gene alterations between early and delayed mutations induced by UV‐B radiation. For UV‐A radiation the deletion spectra were similar for delayed and early mutations. UV‐A radiation is, in contrast to UV‐B radiation, only weakly absorbed by DNA and probably induces mutation almost solely via production of reactive oxygen species. Therefore, the present results support the hypothesis that persistent increase in oxidative stress is involved in the mechanism of UV‐induced genomic instability.
Photochemistry of Phytoalexins Containing Phenalenone‐like Chromophores: Photophysics and Singlet Oxygen Photosensitizing Properties of the Plant Oxoaporphine Alkaloid Oxoglaucine¶
Authors: Flors Cristina , Prat Chantal , Suau Rafael , Nájera Francisco , Nonell Santi 
Published: July 2010

ABSTRACTOxoglaucine (OG) is an oxoaporphine alkaloid, which has been linked to plant defense mechanisms. It contains a phenalenone (PN)–like chromophore, which suggests a role as singlet oxygen (1O2) photosensitizer. Indeed, OG is able to photosensitize 1O2 with 100% efficiency in nonpolar environments, similar to PN. However, this efficiency decreases in polar and protic media, although 1O2 is formed in all environments ranging from benzene to water. OG is a rather inefficient 1O2 quencher (kq= 8 × 105M−1 s−1) unlike the related alkaloids boldine and glaucine, for which an antioxidant role has been suggested. The results of this study contribute to the view that plant defense mediated by PN‐like secondary metabolites may have a photochemical component.
PhotochemCAD 2: A Refined Program with Accompanying Spectral Databases for Photochemical Calculations¶
Authors: Dixon James M. , Taniguchi Masahiko , Lindsey Jonathan S. 
Published: July 2010

ABSTRACTThe PhotochemCAD program has been revised extensively. Calculations can be performed using eight modules (oscillator strength, transition dipole moment and natural radiative lifetime, Förster energy transfer, multicomponent analysis, blackbody radiator, artificial spectrum creation, transmission calculation, and analysis of energy transfer among linear multichromophore arrays). The user interface has been streamlined to facilitate visual display, operation of the various modules, input of user data via a wizard and output of spectra and calculations. The database of absorption and fluorescence spectra has been expanded to 150 photochemically relevant compounds. A database of solar spectra has been added. The program runs under Windows and is equipped with extensive literature references and help features, including a tutorial section with video files.
Photobleaching of Melanosomes from Retinal Pigment Epithelium: II. Effects on the Response of Living Cells to Photic Stress
Authors: Zareba Mariusz , Sarna Tadeusz , Szewczyk Grzegorz , Burke Janice M. 
Published: July 2010

AbstractMelanosomes of the retinal pigment epithelium (RPE) are long lived organelles that may undergo photobleaching with aging, which can diminish the antioxidant efficiency of melanin. Here, isolated porcine RPE melanosomes were experimentally photobleached with visible light to simulate aging and compared with untreated granules or control particles (black latex beads) for their effects on the survival of photically stressed ARPE‐19 cultures. Particles were delivered to cultures for uptake by phagocytosis then cells were exposed to violet light and analyzed by a new live cell imaging method to identify the time of apoptotic blebbing as a dynamic measure of reduced cell survival. Results indicated that untreated melanosomes did not decrease photic injury to ARPE‐19 cells when compared with cells lacking particles or with cells containing control particles, as might be expected if melanin performed an antioxidant function. Instead cells with untreated melanosomes showed reduced survival indicated by an earlier onset of blebbing and a lower fraction of surviving cells after photic stress. Cell survival was reduced even further in stressed cells containing melanosomes that were photobleached, and survival decreased with increasing photobleaching time. Photobleaching of RPE melanosomes therefore makes cells containing them more sensitive to light‐induced cytotoxicity. This observation raises the possibility that aged melanosomes increase RPE cell photic stress in situ, perhaps contributing to reduced tissue function and to degeneration of the adjacent retina that the RPE supports. How melanosomes (photobleached or not) interact with their local subcellular environment to modify RPE cell survival is poorly understood and is likely determined by the physicochemical state of the granule and its constituent melanin. The live cell imaging method introduced here, which permitted detection of a graded effect of photobleaching, provides a sensitive bioassay for probing the effects of melanosome modifications.
Determination of Wavelength‐Specific UV Protection Factors of Sunscreens in Intact Skin by EPR Measurement of UV‐Induced Reactive Melanin Radical
Authors: Lund Leslie , Ley Ronald D. , Felton Linda A. , Timmins Graham S. 
Published: July 2010

ABSTRACTThere remains an unmet need for skin tissue‐based assays for the measurement of the UVA protection and efficacy of sunscreens. Here we describe development of a novel electron paramagnetic resonance assay that uses the photogeneration of reactive melanin radical as a measure of UV light penetration to melanocytes in situ in skin. We have used areas of focal melanocytic hyperplasia in the skin of Monodelphis domestica to model the human nevus. We show that we are able to use this assay to determine the monochromatic protection factors (mPF) of research and commercial sunscreens at specific narrow wavebands of UVB, UVA and blue visible light. Both commercial sunscreens, a sun protection factor (SPF) 4 and an SPF 30 product, had mPFs in the UVB range that correlated well with their claimed SPF. However, their mPF in the UVA ranges were only about one‐third of claimed SPF. This technique can be used to design and assay sunscreens with optimally balanced UVA and UVB protection.
Motility of Daphnia spinulata as Affected by Solar Radiation Throughout an Annual Cycle in Mid‐latitudes of Patagonia†
Authors: Gonçalves Rodrigo J. , Barbieri Elena S. , Villafañe Virginia E. , Helbling E. Walter 
Published: July 2010

AbstractDuring an annual cycle, Daphnia spinulata collected from a plankton community of Patagonia was exposed outdoors to assess the impact of recently received solar radiation on motility (i.e. swimming speed and gravitaxis). Individual values of these parameters were obtained by video recordings and image analysis at different time intervals during the day. Initial swimming speed varied throughout the year, and changes in speed during exposure were not significantly affected by any waveband used in our experimental design (i.e. PAB, 280–700 nm; PA, 320–700 nm; and P, 400–700 nm). Overall, most of the individuals swam downwards, regardless of the radiation treatment imposed to the samples. We found that multifactor interactions (i.e. not a single parameter explained more than 40% of the observed variability) explained most of our observations on motility parameters. These factors include not only solar radiation, but other physical (underwater radiation field and wind intensity) and biological parameters (food availability, presence of predators and congeners). Our findings indicate that the plankton dynamics in the study site is likely to be governed by a sum of factors which must be taken into account when considering solar radiation effects on aquatic ecosystems.
PAR and UV Effects on Vertical Migration and Photosynthesis in Euglena gracilis†
Authors: Richter Peter , Helbling Walter , Streb Christine , Häder Donat‐P. 
Published: July 2010

AbstractRecently it was shown that the unicellular flagellate Euglena gracilis changes the sign of gravitaxis from negative to positive upon excessive radiation. This sign change persists in a cell culture for hours even if subsequently transferred to dim light. To test the ecological relevance of this behavior, a vertical column experiment was performed (max. depth 65 cm) to test distribution, photosynthetic efficiency and motility in different horizons of the column (surface, 20, 40 and 65 cm). One column was covered with a UV cut‐off filter, which transmits photosynthetically active radiation (PAR) only, the other with a filter which transmits PAR and UV. The columns were irradiated with a solar simulator (PAR 162 W m−2, UV‐A 32.6 W m−2, UV‐B 1.9 W m−2). The experiment was conducted for 10 days, normally with a light/dim light cycle of 12 h:12 h, but in some cases the light regime was changed (dim light instead of full radiation). Under irradiation the largest fraction of cells was found at the bottom of the column. The cell density decreased toward the surface. Photosynthetic efficiency, determined with a pulse amplitude modulated fluorometer, was negligible at the surface and increased toward the bottom. While the cell suspension showed a positive gravitaxis at the bottom, the cells in the 40 cm horizon were bimodally oriented (about the same percentage of cells swimming upward and downward, respectively). At 20 cm and at the surface the cells showed negative gravitaxis. Positive gravitaxis was more pronounced in the UV + PAR samples. At the surface and in the 20 and 40 cm horizons photosynthetic efficiency was better in the PAR‐only samples than in the PAR + UV samples. At the bottom photosynthetic efficiency was similar in both light treatments. The data suggest that high light reverses gravitaxis of the cells, so that they move downward in the water column. At the bottom the light intensity is lower (attenuation of the water column and self shading of the cells) and the cells recover. After recovery the cells swim upward again until the negative gravitaxis is reversed again.
“I'M A Firebug, Lady”
Authors: Macpherson Charlene 
Published: July 2010

Editorial Comment: Your Editor unblushingly, and with some pride, confesses that he lifted the article which follows from the April issue of THE BULLETIN, official publication of the WOMEN'S CLUB OF UPPER MONTCLAIR, is located nearabout the city of Newark, New Jersey.Now Newark is the place where Harry W. Lindeman and Horace S. Bellejato hold Court and dispense parental justice to children of that large city who go astray or are neglected.They figure prominently (and properly) in the article.Also is mentioned our immediate past president, G. Bowdon Hunt, who gave with some quotable quotes. Moreover there is much about the Day in Court and pioneer adventures, such as Highfields, the Community Adjustment Conference and other fruits, mainly of the leadership of the two judges of this area mentioned above.Another thing: Charlene MacPherson, Director, Public Affairs, is a superlative writer.The Editorial Pride first mentioned arises from the fact that the Editor believes he knows good writing when he sees it. He also thinks he knows good judges.Just this last comment: if purloining this piece is larceny in any degree the defendant editor is willing to make a pauper's oath as to his indigency and ignorance.Now read, “I'M A FIREBUG, LADY.”