bluuebunny/crossref_metadata_2025 huggingface dataset:
RECURRING GYNAECOLOGIC CANCER TREATED WITH PHOTODYNAMIC THERAPY
Authors: Corti L. , Tomio L. , Maluta S. , Minucci D. , Fontana M. , Cittar H. , Calzavara F.
Published: January 2008

Abstract Tumor recurrences in the gynaecological field after conventional therapy are a big problem because there is little choice for other therapy without inflicting further damage. Photodynamic therapy (PDT) is indicated because it is selective and without side‐effects in flat or small recurrences.

We treated 12 patients with vaginal and vault recurrences of cervix carcinoma, adenocarcinoma corpus uteri and rectum. The PDT was performed after 24‐48 h with Hp, 5 mg kg’body wt injection, using an argon‐dye laser for 10 cases, tungsten and xenon lamps in two cases. All patients were previously treated with conventional therapy (i.e. surgery, radiotherapy, chemotherapy). Doses ranged from 60 to 300 J cm−2. The results were 7 complete local with 4 partial responses, and 1 with no change. Three patients died because of distant metastases, 1 partial response was treated with brachytherapy and is now disease free. All the other patients are still living. In all cases we have seen no side‐effects from PDT. The patients were sheltered from the sunlight for 20‐30 days after therapy.

We recently used a new argon‐pumped CW dye laser. This high‐power argon laser consists of 2 argon tubes in series which emit green light up to 10 W and at 630 nm up to 3 W. We are evaluating the high power to see if this improves the results.
ERGOSTEROL (PROVITAMIN D2) TRIPLET STATE: AN EFFICIENT SENSITISER OF SINGLET OXYGEN, O2(1Δg), FORMATION
Authors: Gorman A. A. , Hamblett I. , Rodgers M. A. J.
Published: January 2008

The triplet state of ergosterol (provitamin D2) has been produced in benzene by pulse radiolysis and characterised in terms of absorption spectrum, lifetime, self‐quenching properties and relaxed triplet energy. The amount of singlet oxygen, O2(1Δg), produced as a consequence of the oxygen quenching of this species has been determined by kinetic infrared emission spectroscopy. Ergosterol is significantly more efficient as a singlet oxygen sensitiser in benzene than is naphthalene, the absolute standard employed in this work.
PHOTOADDUCTS OF 8‐METHOXYPSORALEN TO CYTOSINE IN DNA
Authors: Calvin Noel M. , Hanawalt Philip C.
Published: January 2008

Abstract— The isolation and partial characterization of several photoadducts formed between 8‐methoxypsoralen (8‐MOP) and cytosine is described. The formation of these adducts was analysed in E. coli DNA containing 3H‐labeled cytosine and/or 14C‐labeled thymine, and in oligonucleotides of defined sequence. The major initial adduct has been identified as an 8‐MOP cytosine monoadduct, most likely forming at the pyrone end of the 8‐MOP molecule. Further irradiation converts this adduct to several other species, including both cytosine:cytosine and cytosine:thymine diadducts, as well as a number of derivative monoadducts. One isomer of the C:T diadduct appears to undergo a reversible isomerization under the conditions normally used to analyse adduct mixtures by HPLC. The isomerization can cause this adduct to exhibit a retention time on reversed‐phase HPLC closely resembling either that of a thymine‐thymine crosslink or a thymine monoadduct.
PHOTOREVERSIBILITY OF UV‐INDUCED THYMINE DIMERS AND ABNORMAL MORPHOGENESIS IN SEA‐URCHIN EMBRYOS
Authors: Akimoto Yoshihiro , Shiroya Tsugio
Published: January 2008

Abstract— Irradiation of synchronously dividing 16‐cell embryos of a sea‐urchin (Hemicentrotus pul‐cherrimus) with 200 J m−2 of UV light (254 nm) resulted in the complete inhibition of normal pluteus‐larva formation when the embryos were cultured in the dark after UV‐irradiation. Illumination of the UV‐irradiated embryos with visible light (11 W m−2) for 1 h immediately after the UV‐irradiation reversed the abnormal morphogenesis. Measurement of thymine dimers indicates that the degree of UV‐induced abnormal morphogenesis is greatly correlated with the amount of thymine dimers in the DNA of the embryos. The degree of the photoreversal decreased with an increase in the interval between UV‐irradiation and exposure to visible light. Visible light was ineffective as to the reversibility of both thymine dimers and the abnormal morphogenesis at 60 min after the UV‐irradiation, when the UV‐irradiated 16‐cell embryos entered the next cell cycle.
THERMOLUMINESCENCE EVIDENCE FOR CHLORIDE REQUIREMENT IN THE S2→S3 TRANSITION OF THE WATER‐SPLITTING SYSTEM
Authors: Rozsa Zsuzsa , Demeter Sandor
Published: January 2008

Abstract— The role of chloride in photosynthetic oxygen evolution was investigated by means of thermoluminescence measurements. It was found that chloride depletion in isolated chloroplasts almost completely abolished the B1 thermoluminescence band (S3QB− recombination) but diminished only slightly the amplitude of the B2 band (S2QB− recombination). The B2 band could be excited to full intensity by the first flash of a flash series and subsequent flashes caused no further change in the amplitude of the band. These observations suggest a block in the S2→S3 transition of the water‐splitting system in chloride‐depleted chloroplasts. Readdition of chloride provided evidence that the inhibitory effect of chloride removal is reversible.
BIOLOGICAL ACTIVITIES OF PHTHALOCYANINES—V. PHOTODYNAMIC THERAPY OF EMT‐6 MAMMARY TUMORS IN MICE WITH SULFONATED PHTHALOCYANINES
Authors: Brasseur Nicole , Ali Hasrat , Langlois Réjean , Wagner J. Richard , Rousseau Jacques , Lier Johan E. van
Published: January 2008

Abstract— We tested water‐soluble sulfonated phthalocyanine and three metal chelate derivatives for their tumoricidal effect on the EMT‐6 mammary tumor in mice exposed to red light. The metal‐free sulfophthalocyanine had little effect, whereas the aluminum complex and the lower sulfonated fraction of the gallium complex exhibited tumoricidal activity similar to hematoporphyrin‐based photosensitizer (Photofrin II). The higher sulfonated fractions of the gallium complex were less active as compared to the lower sulfonated fraction. The cerium complex was the most active sensitizer in terms of dye and light doses required to induce tumor necrosis and cure but also showed the highest phototoxicity towards healthy skin. These results suggest that sulfonated phthalocyanines will offer a new alternative in photodynamic therapy of light‐accessible neoplasms.
COMPARISON OF UV ACTION SPECTRA FOR LETHALITY AND MUTATION IN Salmonella typhimurium USING A BROAD BAND SOURCE AND MONOCHROMATIC RADIATIONS
Authors: Calkins John , Selby Christopher , Enoch Harry G.
Published: January 2008

Abstract— The UV‐B region (280–320 nm) is thought to be primarily responsible for the mutagenic, lethal, and carcinogenic effects of solar radiation. We have conducted UV‐B action spectroscopy for mutagenesis and survival of Ames' Salmonella typhimurium strain TA98 (uvrB, pKM101) using both monochromatic radiation from a dye laser and broader bandwidth radiation emitted from FS‐20 sunlamps. A series of optical filters having different transmission cut‐offs together with the sunlamp source provided bandwidths having successively less short wavelength components from which a “broad band” action spectrum was deduced. The two sets of action spectra differed both qualitatively and quantitatively: in comparison to the monochromatic action spectra, the “broad band” spectra showed up to a 200‐fold reduced efficiency for both mutation induction and lethality by UV‐B wavelengths. These results suggest a large protective effect of the background UV‐A and/or visible radiations which were present during the broad spectrum irradiations and which are also present in solar radiation. Additional experiments show that to the extent tested this protective effect is not due to photo‐reactivation or irradiance (dose rate) effects
X‐RAY MICROANALYSIS OF THE EFFECT OF ILLUMINATION ON THE IONIC COMPOSITION OF THE OCTOPUS PHOTORECEPTOR
Authors: Takagi M. , Salehi S. A. , Nakagaki I. , Sasaki S.
Published: January 2008

Abstract— The concentrations of Na+, K+, Ca2+, Mg2+ and CI− ions in the cytoplasm of octopus photoreceptor cells were determined before and after illumination by electron probe X‐ray microanalysis. The concentrations of these elements in the dark‐adapted photoreceptor cells were: Na+, 68.4; K+, 111.4; Ca2+, 4.0; Mg2+, 16.4; and CI−, 102.9 mM/kg of cytoplasm. Illumination raised the concentration of Na+ by 58 mM and that of Cl− by 23 mM and reduced the K+ concentration by 47 mM/kg of cytoplasm. A trace increase of intracellular Ca2+ and a trace decrease of Mg2+ were observed. These results confirm the hypothesis that sodium ions flow in on illumination, and suggest the influx of chloride ions and the outflux of potassium ions during illumination. The intracellular concentrations of Na+, K+ and Cl+ can give the basis for calculating the ion permeability of ion channels in octopus photoreceptor cell membranes, using values of the membrane potentials obtained by electrophysiological studies
EPR SPECTROSCOPY OF ETHIDIUM NITRENE AND PROFLAVINE NITRENE COORDINATED TO SELF‐COMPLEMENTARY DINUCLEOTIDE MINI‐DUPLEXES
Authors: Soundaramani S. , Haider Karl , Platz Matthew S.
Published: January 2008

Abstract— Photolysis of ethidium azide (lb) and proflavine azide (2b) immobilized in glassy media at 77 K produces triplet EPR spectra of the corresponding triplet nitrenes lc and 2c. The resonance field positions of the nitrenes are shifted by the presence of self‐complementary dinucleotides. Control experiments indicated that the interaction of lc and 2c with CPG mini‐duplexes is consistent with intercalation.
MIXED PRODUCTS OF THYMINE AND CYSTEINE PRODUCED BY DIRECT AND ACETONE‐SENSITIZED PHOTOREACTIONS
Authors: Shetlar Martin D. , Hom Kellie
Published: January 2008

Abstract. The nature of the major mixed products of the photoreaction of thymine with L‐cysteine has been restudied. Our results, from application of recent advances in separation and spectroscopic technology to this problem, allow extension and require major revision of the published descriptions of the products produced in this system. We have found that the previously described major mixed photoproduct in the system, 5‐S‐L‐cysteinyl‐5, 6‐dihydrothymine, can be readily separated into diasteromers (Ia and Ib) that have quite different chromatographic and NMR spectral properties. Confirming previously published work, 5‐S‐L‐cysteinylmethyluracil (III) was also produced. Major modifications in the published descriptions of other mixed photoproducts produced in the photoreaction of thymine with cysteine are the following. While the product 5‐S‐L‐cysteinylmethyl‐5, 6‐dihydrouracil (II) is indeed produced, it does not correspond in its properties to the compound previously reported as this substance. Our experimental findings also indicate that observations, previously interpreted to imply formation of the disulfide 5‐S, S‐L‐cysteinyl‐5, 6‐dihydrothymine (IV), can instead be explained in terms of the properties of the β‐carbamoylsulfide functionality contained in Ia and Ib. Indeed, both diastereomers of the addition product of L‐cysteine with N‐ethylmaleimide, S‐(l‐ethyl‐2, 5‐dioxopyrrol‐idin‐3‐yl)‐L‐cysteine (VI), as well as 5‐carbamoyl‐4‐thiapentanoic acid (VII), exhibit properties assumed in the previous work to be specific to disulfide linkages; each of these compounds contains a β‐carbamoylsulfide functionality. Acetone photosensitization of reaction in the thymine‐cysteine system also yielded Ia, Ib, II and III as products. Again, no evidence was found for formation of IV.
ACTION SPECTRA FOR HYPHAL AGGREGATION, THE FIRST STAGE OF FRUITING, IN THE BASIDIOMYCETE Pleurotus ostreatus*
Authors: Richartz Gisela , Maclellan Andrew J.
Published: January 2008

Abstract. Action spectra were determined for hyphal aggregation in Pleurotus ostreatus at wavelengths between 360 and 600 nm. The action spectrum for a 50% response had two maxima, one at 370 nm in the near‐UV and the other a broad peak at 440–450 nm in the blue. Both were approximately of the same magnitude. A minimum was present at 400 nm and wavelengths greater than 530 nm invoked no response. Action spectra for a range of responses, 10–90%, were also determined which showed gradual changes in the peaks in the blue region. It was concluded that hyphal aggregation in P. ostreatus is under the control of a cryptochrome‐like photoreceptor system.
EXCITATION ENERGY TRANSFER BETWEEN SENSITIZING CHROMOPHORES OF PHYCOCYANIN 612
Authors: Csatorday Károly , MacColl Robert , Guard‐Friar Deborah , Hanzlik Cheryl A.
Published: January 2008

Abstract. The visible absorption and circular dichroism spectra of phycocyanin 612 were each resolved into four components. The deconvolution required the blue side of each spectrum to be fitted by a half‐Lorentzian band and the remainder of the spectrum by Gaussian components. The energy levels of the components in the deconvolution allowed analysis of the discrete steps in the transfer of excitation energy within the biliprotein. By comparison of the deconvolution of the absorption spectrum to the published results from ultrafast fluorescence kinetics of phycocyanin 612, the times for s‐to‐s and s‐to‐f excitation energy transfer are established. This is the first evidence of excitation energy transfer between two types of sensitizing (s) chromophores in a biliprotein. The analysis of the ultrafast kinetics and the deconvolution of the absorption spectrum allowed the assignments of 7–10 ps to the transfer of excitons from an s to a fluorescing (f) chromophore and a time faster than 7 ps to the transfer of excitons between two spectrally distinct s chromophores. The steady‐state fluorescence polarization spectrum of this biliprotein supports the hypothesis that excitation energy transfer occurs between s chromophores.
IS DNA TOPOISOMERASE INVOLVED IN THE UV EXCISION REPAIR PROCESS? NEW EVIDENCE FROM STUDIES WITH DNA INTERCALATING AND NON‐INTERCALATING ANTITUMOR AGENTS
Authors: Snyder Ronald D.
Published: January 2008

Abstract— The effects of selected DNA intercalating and non‐intercalating drugs on the UV excision repair process in human fibroblasts have been examined. 9‐Amino acridine, acridine orange, quinacrine, doxorubicin (adriamycin), ethidium bromide and actinomycin‐D all inhibited the removal of pyrimidine dimers from cellular DNA by inhibiting the incision process as monitored by the nick translation assay and by an endonuclease‐sensitive site assay. These agents also partially inhibited incision by the M. luteus endonuclease in an in vitro system. This is the only class of compounds tested to date that appears to block this early step of repair in mammalian cells. The DNA topoisomerase inhibitors, m‐amsacrine and VP‐16 (etoposide) and the bacterial gyrase inhibitors nalidixic acid and oxolinic acid were shown not to inhibit UV repair. As shown previously, however, novobiocin does block dimer removal and we show here that it is a potent inhibitor of the M. luteus UV endonuclease. While it has recently been demonstrated that many DNA intercalating agents block the strand‐passing activity of DNA topoisomerase II giving rise to protein associated DNA strand breaks, the finding that the specific inhibitors of topoisomerase, m‐AMSA and VP‐16, do not inhibit repair, even though they block this strand passing activity, strongly suggests that inhibition of DNA topoisomerase is not associated with inhibition of DNA repair.
PHOTORECEPTOR INTERACTION IN PLANT PHOTOMORPHOGENESIS: THE LIMITS OF EXPERIMENTAL TECHNIQUES AND THEIR INTERPRETATIONS
Authors: Gaba Victor , Black Michael
Published: January 2008

Abstract— Problems concerning the interpretation of interactions of higher plant photomorphogenetic receptors are discussed. The theory that action of a blue light photoreceptor serves only to maintain responsiveness to phytochrome (Responsiveness Theory) is demonstrated to be unable to be properly tested with present techniques. This theory is also unable to explain experimental results any better than an alternative theory that a blue light photoreceptor may require the presence of the active form of phytochrome to express its activity (Presence Theory). This tatter theory is also incapable of being fully tested. There does not appear to be an adequate current theory to explain photoreceptor interactions. Other issues discussed include the use of displacement transducers in growth studies, the induction of phytochrome‐type responses by blue light, and the relative importance of the photoreceptors. New data are introduced on the effect of blue light in the end‐of‐day growth response to phytochrome of the light‐grown Cucumis sativus L. hypocotyl, and on the light equivalence principle in the same species.
PHOTO‐CIDNP AS A TOOL FOR THE STUDY OF THE REACTIVITY OF PHOTOSENSITIZING DRUGS: THE FUROCOUMARINS
Authors: Marko J. , Vermeersch G. , Febvay‐Garot N. , Lablache‐Combier A. , Moron J. , Bisagni E.
Published: January 2008

Abstract— Several monofunctional and bifunctional furocoumarin derivatives were studied by means of the photo‐CIDNP technique. Nuclear spin polarizations were observed on some of these derivatives when irradiated in acetonitrile solutions. The likely occurrence of both semi‐reduced and semi‐oxidized species of the FC in the reaction scheme is discussed.

When N‐acetyltyrosine was added to the solution, CIDNP effects were observed on both reactants. They arose from a highly reversible pathway, as no photoproduct was polarized. On the FC part, the stronger effects were always observed on the 3,4 pyrone double bond suggesting that it must possess the highest spin density in the reaction intermediate. According to previous studies, the latter should be the FC anion or neutral radical. For the amino‐acid moiety, the intensity of the polarizations was strongly dependent on the nature of the FC. This allowed the classification of the FC into three groups (zero, weak and strong intensities). As compared with their photobiological reactivity, this classification seemed to be related to the usual mono‐ and bifunctional distinction. This is the second example showing that photo‐CIDNP could be used as a preliminary test for the study of the photosensitizing drug properties.
THE DEVELOPMENT OF EXCITON MIGRATION ROUTES FOR PHYCOCYANIN 645 AND ALLOPHYCOCYANIN
Authors: Csatorday Karoly , Guard‐Friar Deborah , MacColl Robert , Berns Donald S.
Published: January 2008

Abstract— The origin of the comparatively complex absorption spectrum of the cryptomonad biliprotein, phycocyanin 645 from Chroomonas species, has been investigated by deconvolution of its absorption and CD spectra together with fluorescence polarization studies. The visible absorption and CD spectra were each deconvoluted into four components, three pure Gaussian and one Gaussian‐Lorentzian chimera. The difference spectrum between the visible absorption spectra of partially renatured and partially dissociated protein and the fluorescence polarization spectrum are compared to these deconvolutions. All results are consistent with a previous proposal that band splitting from a pair of strongly‐coupled dipoles contributes to the absorption and CD spectra of this biliprotein. A model for the flow of exciton migration through this protein is presented that incorporates these data [together with appropriate literature reports]. This exciton migration model together with one for the biliprotein, allophycocyanin, includes both strong and very weak coupling of dipoles. This combination of mechanisms has salient influence on the visible absorption spectra and the routes of exciton migration characteristic of these two proteins.
ELECTRON‐DONOR‐ACCEPTOR ORBITAL CORRELATIONS‐VII. INTERMOLECULAR ORBITAL (LCMO) DESCRIPTION OF PHOTOSENSITIZED CHARGE SEPARATION IN A 4‐CENTER UNIT*
Authors: STEVENS B.
Published: January 2008

Abstract— The conditions under which electronically‐excited 1: 1 complexes are expected to produce high yields of separated radical‐ions are presented with reference to the porphyrin‐quinonc system in terms of the symmetry properties of intermolecular orbitals (IMO). These conditions are translated into design properties of a 4‐center photoinduced charge separation unit DDAO in which post‐excitation energy and electron transfer processes result from diabatic internal conversions between singly‐excited configurations differentiated by the location of holes and electrons in valence and conduction IMO of the unit. It is suggested that a major role of the donor pair is the inhibition of diabatic charge recombination by the low intermolecular component of the vibrational overlap integral over isoenergetic ground (DD) and cationic (DD +) configurations.
SINGLET OXYGEN YIELDS AND RADICAL CONTRIBUTIONS IN THE DYE‐SENSITISED PHOTO‐OXIDATION IN METHANOL OF ESTERS OF POLYUNSATURATED FATTY ACIDS (OLEIC, LINOLEIC, LINOLENIC AND ARACHIDONIC)
Authors: Chacon Jorge N. , McLearie James , Sinclair Roy S.
Published: January 2008

Abstract— The triplet state characteristics (spectrum, lifetime and quantum yield) for four dye sensi tisers [methylene blue (MB), erythrosin (ER), haematoporphyrin (HP) and riboflavin (RF)] were determined in methanol by laser flash photolysis and singlet oxygen yields (0.60 to 0.48) from time‐resolved measurements of the 1270 nm near infrared emission. The reaction of singlet oxygen with four long chain unsaturated phenyl esters [oleate (18: 1), linoleate (18: 2), linolenate (18: 3) and arachidonate (20: 4)] was followed quantitatively using the singlet oxygen luminescence technique and also, after continuous420–700 nm irradiation, by HPLC and other analysis of the isomeric product monohydroperoxides. The overall quantum yield of photooxidation (∼10‐2) was shown to be consistent with the observed singlet oxygen quenching constants(2–12 times 104 dm3 mol‐1 s‐1) for the four esters studied and the singlet oxygen lifetime in methanol (τ∼ 9 μs). The isomer product distribution was interpreted in terms of a dual singlet oxygen and radical mechanism, the radical contribution increasing with sensitiser in the order ER = MB < HP ≪ RF, but also showing some dependence on substrate unsaturation. Evidence is presented for singlet oxygen quenching by MB and RF (kO= 1.6 and 6.0 times 107 dm3 mol‐1 s‐1) and for the accelerated photobleaching of the dye sensitisers in the presence of the unsaturated esters.
THE LOWEST EXCITED TRIPLET STATES OF CODEINE AND MORPHINE AND OF THEIR MOLECULAR SUBUNITS VERATROLE AND GUAIACOL
Authors: Slama H. , Basché Th. , Brauchle Chr. , Voitländer J.
Published: January 2008

Abstract— The lowest excited triplet T1 states of the two alkaloids, morphine and codeine, have been investigated by ODMR and emission spectroscopy. The electronic character of their T1 states could be determined by comparing the T1 properties with those of the constituent parts guaiacol and veratrole. The T1 properties, e.g. phosphorescence spectra, zero‐field splitting parameters and triplet sublevel selective decay rates are very similar for the constituent parts and the alkaloids. Thus, in analogy to veratrole and guaiacol, the T1 state of codeine and morphine is assigned to a ππ* state mainly localized on the benzene ring and the attached alkoxy and hydroxy groups. There is no evidence for a contribution from the other subunits, trialkylamine and unsaturated alcohol, to the T1 state of codeine and morphine.
KINETICS OF PHOTOSYNTHETIC APPARATUS ADAPTATION IN Scenedesmus obliquus TO CHANGE IN IRRADIANCE AND LIGHT QUALITY
Authors: Hoffmann Bettina , Senger Horst
Published: January 2008

Abstract— Cells of the unicellular green alga Scenedesmus obliquus grown under high (20 W m‐2) or low (5 W m‐2) irradiancies of white light show all characteristics of sun or shade plants, respectively. When transferred to alternate light conditions, the cells adapt within 6 h. When cells grown under high irradiance of white light are transferred to red (683 nm) or blue (424 nm) light, they show characteristics similar to cells adapted to low or high irradiancies of white light, respectively. This adaptation to different wavelengths takes about 12 h. The underlying changes in the photosynthetic apparatus are discussed.
PHOTOCHEMICAL OXIDATION OF VINDOLINE and 16‐O‐ACETYLVINDOLINE
Authors: J.Filippelli Frank , Reeg S. E. , Sariaslani F.Sima , Duffel M. W. , Rosazza J. P. N.
Published: January 2008

Abstract— Photooxidation of 16‐O‐acetylvindoline in methanol using chlorpromazine‐HCl as a photosensitizing agent produces nearly quantitative yields of an iminium derivative. The 16‐O‐acetylvindol‐ine‐iminium product was characterized spectrally by proton NMR and mass spectrometry; and by chemical reduction with sodium borodeuteride. Proton NMR and mass spectral analyses of the reduced product revealed that deuterium was stereospecifically incorporated into the 3‐a‐position. The iminium product formed by photochemical oxidation is identical to that produced by copper oxidases and peroxidase. Photochemical oxidation provides direct evidence for the involvement of free radicals in Aspidosperma alkaloid transformations.
IMMUNOASSAY OF DNA DAMAGE
Authors: Gasparro Francis P. , Santella Regina M.
Published: January 2008

Abstract— The direct photomodification of DNA by ultraviolet light or the photo‐induced addition of exogenous compounds to DNA components results in alterations of DNA structure ranging from subtle to profound. There are two consequences of these conformational changes. First, cells in which the DNA has been damaged are capable of executing repair steps. Second, the DNA which is usually of very low immunogenicity now becomes highly antigenic. This latter property has allowed the production of a series of monoclonal antibodies that recognize photo‐induced DNA damage. Monoclonal antibodies have been generated that recognize the 4′,5′‐monoadduct and the crosslink of 8‐methoxypsoralen in DNA. In addition, another antibody has been prepared which recognizes the furan‐side monoadduct of 6,4,4′‐trimethylangelicin in DNA. These monoclonal antibodies have been characterized as to sensitivity and specificity using non‐competitive and competitive enzyme‐linked‐immunosorbent assays (ELISA).
PHOTOLYSIS OF THE SINGLE TRYPTOPHAN RESIDUE OF EEL TROPONIN C
Authors: Pigault Claire , Gerard Dominique
Published: January 2008

Abstract— The tryptophan (TRP) residue of eel troponin C was selectively degraded by direct UV irradiation, at 302 nm, in Ar‐saturated solution. Depending on the absence or presence of calcium ions, this TRP residue is exposed to aqueous medium or buried in a hydrophobic environment. Tryptophan loss was determined by both absorption and fluorescence spectroscopy and by amino acid analysis. The photodegradation yield was significantly higher for the exposed TRP residue than for the buried ones. These results give more detail on previous observations on several other proteins and corroborate the predominant influence of the polarity on the photosensitivity of a TRP residue in polypeptidic structures.
ONE‐ELECTRON OXIDATION AND REDUCTION OF AZAPROPAZONE AND PHENYLBUTAZONE DERIVATIVES IN AQUEOUS SOLUTION: A PULSE RADIOLYSIS STUDY
Authors: Jones R. A. , Navaratnam S. , Parsons B. J. , Phillips G. O.
Published: January 2008

Abstract— Using pulse radiolysis techniques, 3 azapropazone and 3 phenylbutazone derivatives all structurally related to the potentially photosensitive anti‐inflammatory drug, azapropazone, have been reacted with the free radical oxidants N3, Br2‐ and (SCN)2‐ as well as with e‐aq a strong reductant. It is demonstrated that for 5 derivatives, azapropazone (Az), 2‐[a‐Carboxy‐valeryll‐3‐dimethylamino‐7‐meth1‐1,2‐dihydro‐1,2,4‐benzotriazine (Mi307), phenylbutazone (PB), oxyphenylbutazone (OPB), and ketophenylbutazone (KPB), N3‐ and Br2‐ appear to react via a one‐electron removal process. For the other derivative, 8‐hydroxy azapropazone (8‐OH‐Az), Nj and (SCN); oxidise via a one‐electron process, while Br2‐ probably fqrms a free radical adduct.

The absolute spectra of the one‐electron oxidised and reduced transient species for all six derivatives are thus given in this work and are a basis to the understanding of the action of light on these drugs.
PHOTOELECTROCHEMICAL STUDIES OF METALLOPORPHYRINS
Authors: Basu J. , Rohatgi‐Mukherjee K. K.
Published: January 2008

Abstract— The electro‐oxidation of Ni(II)TVyPP and Zn(II)TVyPP in organic solvent (CH2‐C12) leads to the deposition of ca. 500 monolayer equivalents of electroactive porphyrin films which have been characterised by cyclic voltammetry. The films are stable towards organic solvents and aqueous acids and bases, but are removed by treatment with hot concentrated acids. The Laser Raman spectrum of NiTVyPP film indicates that all the four vinyl groups are saturated. No film is formed if the metal and not the ring is oxidised.
RESPONSES OF THE PLANARIAN Dugesia dorotocephala TO ULTRAVIOLET RADIATION OR PHOTOSENSITIZED TREATMENTS
Authors: LYTLE C. David , Hsu Jonia , Faw Jean M. , Miller Charles W.
Published: January 2008

Abstract— The survival of the planarian Dugesia dorotocephala was measured following treatment with germicidal ultraviolet (UV) radiation, with the DNA photosensitizer 8‐methoxypsoralen (8‐MOP) plus near UV radiation, or with the cytoplasm photosensitizer erythrosin plus visible radiation. The typical morphological response of an irradiated animal was lysis, with the head being the most sensitive part. All the survival curves had substantial shoulders. Treatments whose primary target was likely to be DNA (UV irradiation or 8‐MOP plus near UV irradiation) resulted in lysis of part of the planarian population which commenced 24 h or more after treatment and continued over several days. The treatment whose primary target was likely to be the membranes of the planarian (erythrosin plus visible irradiation) resulted in lysis mostly during the first few hours after treatment. Thus an easily discerned endpoint, lysis, can be used for D. dorotocephala to evaluate photosensitizing compounds, where the kinetics of lysis may differentiate among compounds whose modes of action are different.
WEIGLE‐REACTIVATION IN A CYANOBACTERIUM (Synechococcus PCC7934) IS INDUCED BY UV BUT NOT BY MITOMYCIN‐C OR NALIDIXIC ACID
Authors: Lanham Patrick G. , Houghton James A.
Published: January 2008

Abstract— The cyanobacterium Synechococcus PCC7943 (Anacystis nidulans 602) exhibited UV induced Weigle‐reactivation of irradiated cyanophaseAs–1. Weigle‐reactivation had a half‐life of approximately 34 min. It was not induced by treatments with the SOS inducing agents mitomycin‐C or nalidixic acid.
LOW‐TEMPERATURE PHOTOACOUSTIC SPECTROSCOPY OF PORPHYROPSIN IN THE INTACT RETINA OF THE CREEK CHUB, Semotilus atromaculatus
Authors: Yoon Minjoong , Leblanc Roger M. , Ali M. Ather , Heinermann Peter H.
Published: January 2008

Abstract— The photoacoustic spectra of porphyropsin in the creek chub (Semotilus atromaculatus) have been successfully measured on single retinae of small size (< 0.5 cm in diameter) at low temperatures. The relative intensities of the spectra, corresponding to the thermal release, are strong enough to be comparable to those for the big cattle retina. The photoacoustic spectrum of porphyropsin at – 167°C exhibits a principal maximum at 540 nm with a small shoulder near 580 nm. A sequence of porphyropsin bleaching resulted from thermal reaction has been clearly observed above ‐90°C.
AN INEXPENSIVE AUTOMATIC RECORDER FOR BIOLOGICALLY IMPORTANT SOLAR UV
Authors: KIIXICK H. J. , Primarolo A. A. , Mackenzie R. M. , Forkner A. C.
Published: January 2008

Abstract— An automatic recorder for biologically important solar UV for field use, employing polysul‐phone films is described.
IRREVERSIBLE BINDING OF NITROFURANTOIN TO SKIN AND TO PLASMA PROTEINS OF UV‐A EXPOSED RATS
Authors: Busker Ruud W. , van Henegouwen Gerard M. J. Beijersbergen , Ballegooie Ed. P. van , Vasbinder Wendie
Published: January 2008

Abstract— Allergic reactions to the widely applied urinary tract disinfectant nitrofurantoin (NFT) often concern the skin. They are probably mediated by a NFT‐protein adduct. which has been suggested to result from incomplete nitro‐reduction during metabolism. In this study it was investigated whether photoactivation of NFT in rats, upon exposure to UV‐A, leads to formation of adducts between the drug and biomacromolecules. Rats were given p.o. doses of [14C]‐NFT, and some were exposed to UV‐A. More irreversible binding was found in skin of the back (both in dermis and in epidermis). tail, ears, eyes, plasma proteins, and spleen of light‐exposed rats compared to those kept in the dark. This photobinding increased (up to ∼0.6 nmol/mg protein =∼25 nmol/g tissue) with dose and light‐intensity. When rats were kept at 32°C, instead of 22°C during NFT/UV‐A treatment, even more irreversible binding was observed; this is probably caused by an increased dermal blood flow. Under these conditions, irreversibly bound radioactivity was even found in kidney, lung and liver. Irreversible binding in these inner organs is explained by systemic distribution of radioactivity, photobound to plasma proteins. Photodecomposition of NFT in the skin, followed by reaction of photoproducts with (cellular) biomacromolecules may explain some of the skin rashes and other (allergic) reactions reported for this drug.
THE VISUAL PIGMENT CYANIDE EFFECT
Authors: Crescitelli Frederick , Karvaly Bela
Published: January 2008

Abstract— The visual pigment of the Tokay gecko (Gekko gekko) with its in situ absorption maximum at 521 nm has its spectral position at 500 to 505 nm when chloride‐deficient digitonin is used for the extraction. In this case the addition of chloride or bromide to the extract restores the maximum to 521 nm. This property, characteristic of gecko pigments in general, does not occur with any of the rhodopsins that have been tested. Simple salts of cyanide, a pseudohalogenoid with an ionic radius close to those of chloride and bromide and/or its hydrolysis product attacks both this gecko pigment and rhodopsins in the dark. This is seen as a slow thermal loss of photopigment if (sodium) cyanide is present at concentrations above 40 mM for the gecko pigment and 150 mM for the rhodopsins of the midshipman (Porichthys notatus) and of the frog (Rana pipiens). In all cases the loss of the photopigment is accompanied by the appearance of a spectral product with maximum absorption at about 340 nm. Cyanide addition has no effect on the photosensitivity of the native pigments and neither does it alter, as do chloride, bromide and other anions, the spectral absorbance curve. The spectral product at 340 nm also appears when the visual pigments are photolyzed in the presence of cyanide salts below the threshold concentrations given above. Incubation of digitonin‐solubilized all‐trans‐relina with (sodium) cyanide leads to a reaction product with absorption spectrum similar to that obtained with visual pigments under comparable conditions. We suggest that cyanide addition leads to conformational changes in the visual pigment that results in the release of the retinal chromophore. This is followed by a direct attack of cyanide on the retinal to form the product absorbing in the near ultraviolet. The special point of interest here is that both the gecko 521‐pigment and the rhodopsins are similarly attacked by cyanide addition and form the same product. It is also suggested that this product is an α‐hydroxy acid derivative of retinoic acid, probably α‐hydroxy homoretinoic acid. The opsin site selected by the cyanide action is apparently similar for both classes of visual pigments but must be different from the site in the gecko pigment with which chloride and bromide react. The cyanide‐effect implies that retinal binding and/or Schiffs‐base stability in visual pigments are allosterically controlled. Finally, some practical analytical aspects of this novel effect are discussed.
THE PHOTOPHOBIC RESPONSE OF VARIOUS SULFUR AND NONSULFUR PURPLE BACTERIA
Authors: Hustede E. , Liebergesell M. , Schlegel H. G.
Published: January 2008

Abstract— The photophobic response of 34 strains of nonsulfur and sulfur purple bacteria was examined with respect to response‐eliciting light intensities. The bacteria were grown in defined synthetic media or in Winogradsky columns. Two population methods based on Engelmann's light trap were used to determine the discrimination thresholds of the bacteria. A single‐side irradiation method allowed the estimation of approximate values, while the double‐side irradiation method provided more exact values of the discrimination threshold. Sixteen strains belonging to 9 different species exhibited discrimination thresholds between 0.7% and 2.6%. The motility of the other 18 strains proved to be insufficient to measure light sensitivities with the methods used. The effect of various environmental factors on the light sensitivies of Chromatium vinosum D and Rhodospirillum rubrum Ha was examined. The measurements and observations made in this work recommend strains of Rhodospirillum rubrum and Chromatium vinosum as model organisms for further studies.
THE PHOTOPHYSICAL PROPERTIES OF SOME C15 LUPINE ALKALOIDS:
Authors: Halpern ARTHUR M. , FALCK CHRISTIAN , LEGENZA MICHAEL W.
Published: January 2008

Abstract Sparteine, the tetracyclic saturated amine alkaloid, is highly fluorescent in n‐hexane solution (Φf= 0.64; ζ= 63 ns) and has a large Stokes shift [λmax (abs) = 203 nm; λmax (fluor) = 325 nm]. Its isomer, α‐isosparteine, has similar properties: Φf= 0.55; ζf= 50 ns; λmax (fluor) = 338 nm. Oxidized derivatives, such as lupanine, thermopsine, and α‐diplospartyrine, are weakly fluorescent. Based on a comparison with spectroscopic and photophysical properties of the monoamine, quinolizidine, it is concluded that the excitation energy is delocalized over the two N‐atoms in starteine and a‐isosparteine. The self quenching rate constant for sparteine, ca. 1 times 107M‐1 s‐1, is about 100 times smaller than that for quinolizidine, consistent with excited state derealization. The significant fluorescence quenching in lupanine is rationalized by the fact that N‐methyl‐2‐piperidone mfe/molecularly quenches the fluorescence of quinolizidine at nearly the diffusion controlled rate in ‐hexane. Comparisons are made with the fluorescence properties of other diamines such as N, N'‐dimethylbispidine and N, N'‐disubstituted piperazines.
COMPARISON OF PHAGE T4 denV ENDONUCLEASE V AND M. Luteus UV‐DNA ENDONUCLEASE BY SEROLOGY AND DNA HYBRIDIZATION
Authors: YAROSH DANIEL B. , CECCOLI JOSEPH
Published: January 2008

Abstract Antibodies were raised in rabbits against purified endonuclease V, the product of the bacteriophage T4 denV gene, which incises DNA at the site of UV‐induced pyrimidine dimers. These antibodies cross‐reacted with the purified UV‐DNA endonuclease from M. luteus in both enzyme‐linked immunosorbent assay and Western assays. However, no sequence similarity was detected between the denV gene and M. luteus DNA by hybridization. The two endonucleaes are remarkably similar in enzymatic activity, and their antigenic similarities have been preserved despite differences in their DNA sequences.
IS THE DICHROIC PHOTORECEPTOR FOR Phycomyces PHOTOTROPISM LOCATED AT THE PLASMA MEMBRANE OR AT THE TONOPLAST?*
Authors: STEINHARDT A.R. , POPESCU T. , FUKSHANSKY L.
Published: January 2008

Abstract A rigorous quantitative description of the spatially distributed light stimulus and the spatial pattern of photo‐excitation shows that the dichroic photoreceptor for Phycomyces phototropism can not be located at the tonoplast. A photoreceptor located here could not be responsible for the transmission from the positive to negative phototropic bending as observed in sporangiophores immersed in media of varying refractive indices. The calculations support the alternative hypothesis that the photoreceptor is situated at the plasma membrane. Some evidence in favour of a transverse tangential orientation of the transition dipole at 495 tun is also present.
REACTIVITY OF PHOTOCHEMICALLY‐GENERATED LIPID HYDROPEROXIDES IN CELL MEMBRANES WITH GLUTATHIONE PEROXIDASE
Authors: THOMAS JAMES P. , GIROTTI ALBERT W.
Published: January 2008

Abstract The ability of glutathione peroxidase (Gpx) to catalyze the reductive inactivation of phot‐ochemically‐generated lipid hydroperoxides (LOOHs) was investigated, using hematoporphyrin derivative (HPD) as a photosensitizing agent and erythrocyte ghosts as membrane targets. Glutathione peroxidase was reactive toward photoperoxidized membranes only after their exposure to phospholi‐pase A2 (PLA2)‐ Iodometrically‐determined LOOH values were typically 30–40% greater than values measured by enzymatic assay using Gpx and glutathione reductase. A consistent result was obtained when photooxidized membranes were treated with PLA2 and GSH/Gpx followed by iodometric assay, viz. persistence of approximately 40% of the starting LOOH. Whereas photooxidized egg phosphatidylcholine liposomes underwent total LOOH loss when incubated with PLA2 and GSH/Gpx, no net loss was observed with photooxidized cholesterol/dimyristoyl‐phosphatidylcholine liposomes. The results suggest that cholesterol hydroperoxides in ghost membranes account for the Gpx‐resistant fraction of LOOHs.
PHOTOSENSITIZATION WITH DERIVATIVES OF CHLOROPHYLL
Authors: KESSEL DAVID , SMITH KEVIN
Published: January 2008

Abstract The properties of several chlorophyll derivatives were examined: the methyl esters of pheophorbide A, pheophorbide B and pheophytin. In spite of structural differences, all products were equally effective sensitizers in vitro and were localized equally well by murine tumors in vivo after 1 h. But only the pheophytins persisted at neoplastic loci for 24 h. There was no evidence of hydrolysis of the methyl esters, but the phytyl ester linkage was labile in vivo.
LONG‐TERM EFFECTS OF A SINGLE DOSE OF ULTRAVIOLET‐B ON ALBINO RABBIT CORNEA‐I. in vivo ANALYSES
Authors: DOUGHTY MICHAEL J. , CULLEN ANTHONY P.
Published: January 2008

Abstract Both eyes of female albino rabbits (1.9 kg) were exposed to a single dose of UV‐B (300 ± 9 nm; 0.125 J/cm2 total dose) between 13.30 and 15.00 h. The average irradiance was 209 ± 4 μW/cm2 delivered over 612 ± 13 s. At various time periods thereafter (every 12 h for 3 days, 6, 7, 14, 28, 42, 56, 112, 224 and 336 days post‐irradiation), the animals were subjected to a full slit lamp examination to evaluate the status of the cornea and the anterior segment along with optical or ultrasonic pachometry of central corneal thickness. The results were compared with studies on age‐matched rabbits over the same time period. In response to the UV‐B irradiation, the corneas showed a modest edema (20% increase in central corneal thickness) that peaked at 48 h. Nearly normal central cornea] thickness returned in 6 days and followed by a secondary very slight swelling (< 5%) that resolved by 14 days. The edema was accompanied by keratitis over the same period. Thereafter, both control and UV‐B irradiated corneas progressively increased in thickness with age. Biomicroscopy also revealed the appearance of granular opacities in the corneal epithelium that peaked at 72–96 h and resolved over 28 days. In addition, very small microdot opacities of the corneal epithelium were present in the UV‐B irradiated corneas that reached maximum at 72 h but persisted to some degree throughout the evaluation period. Biomicroscopy also revealed a progressive disruption of the homogeneous nature of the corneal stroma by the appearance of large ‘bread crumb’‐like opacities that started at 72 h and was still present at the end of the evaluation period. These results suggest that long‐term evaluation of the cornea is important after acute UV‐B exposure and indicate that acute exposure to UV‐R can produce corneal changes resembling those reported following chronic exposure to UV‐R‐rich environments.
THE PHOTOCHEMISTRY OF 2‐ALKOXYCYTOSINES IN PHOSPHATE BUFFER AND ITS LINK TO CYTOSINE PHOTOCHEMISTRY IN ALCOHOLIC SOLUTION
Authors: SHAW ANTHONY A. , SHETLAR MARTIN D.
Published: January 2008

Abstract The reactions occurring when 2‐methoxycytosine (4‐amino‐2‐methoxypyrimidine) (I) and 2‐ethoxycytosine (II) are irradiated in aqueous phosphate buffer at pH 7 have been studied. We have verified the previous results of Moore [Can. J. Chem. 41, 1937–1950 (1963)], who studied I and indicated that the product isolatable in greatest yield is N‐carbomethoxy‐3‐hydroxyacrylamidine (IIIa). Similarly, we have found that the product of highest yield, isolated after irradiation of II, is N‐carboethoxy‐3‐hydroxyacrylamidine (IIIb). Evidence is presented indicating that these are secondary products, being produced through hydrolysis of the corresponding N‐carboalkoxy‐3‐aminoacrylami‐dines. Spectroscopic data are given for N‐carboisopropoxy‐3‐hydroxyacrylamidine (IIIc), as well as the N‐carbomethoxy, N‐carboethoxy and N‐carboisopropoxy derivatives of 3‐hydroxy‐2‐methylacryla‐midine. These four compounds were obtained through hydrolysis of the corresponding N‐carboalkoxy derivatives of 3‐aminoacrylamidine or 3‐amino‐2‐methylacrylamidine, isolated from the photoreaction of cytosine or 5‐methylcytosine with the appropriate alcohol.
FLUORESCENCE OF PHYTOCHROME IN THE CELLS OF DARK‐GROWN PLANTS AND ITS CONNECTION WITH THE PHOTOTRANSFORMATIONS OF THE PIGMENT
Authors: SINESHCHEKOV VITALY A. , SINESHCHEKOV ALEXEI V.
Published: January 2008

Abstract Fluorescence of phytochrome is found in the cells of etiolated monocotyledonous and dicotyledonous plants. The red light‐absorbing form of phytochrome (Pr) fluoresces at 77 K with a yield 0.3±0.1 and maxima at 672–673 nm and 684–686 nm in the excitation and emission spectra, respectively. The emission is characterized by the sharp temperature dependence of its intensity, its high (∼ 40%) polarization, and the violation of the mirror symmetry rule. Connection of the fluorescence with Pr photoreactions is followed in the interval 77–293 K. A P, photoproduct, lumi‐R, is fluorescent with maxima at 696 nm and 705 nm in the excitation and emission spectra; the far‐red light absorbing form of phytochrome (Pfr) is practically nonfluorescent. Three isochromic emitting Pr species are present differing in their photochemical properties: Pr1 and Pr2 which phototransform irreversibly and reversibly at T 170 K into lumi‐R, and lumi‐R2, respectively, and Pr3 which undergoes photoconversion only at T > 240 K. The activation energies of Pr2 and Pr3 photoreactions are evaluated to be 2.9–3.3 kJ/mol and 26 kJ/mol. Complex dynamics of changes of Pr fluorescence and of the extent of its decrease in the photoconversion Pr? Pfr in germinating pea and bean seeds suggests the existence of two Pr pools one of which is incapable of Pr? Pfr phototransformation. Thus, the developed fluorescent method of phytochrome assay and investigation in the cell revealing multiplicity of phytochrome states in vivo proves to be very sensitive (about 1 ng) and informative.
WAVELENGTH DEPENDENCE OF DNA INCISION BY A HUMAN ULTRAVIOLET ENDONUCLEASE
Authors: GALLAGHER PATRICIA E. , WEISS RANDI B. , BRENT THOMAS P. , DUKER NAHUM J.
Published: January 2008

Abstract The wavelength dependence of an ultraviolet irradiation of the DNA substrate for a human endonuclease was determined. Sites of DNA incision for all UVB and UVC wavelengths examined were at cytosines which were neither cyclobutane pyrimidine dimers nor 6–4'‐(pyrimidin‐2‐one)pyrimidines. The optimal wavelenths for formation of these cytosine photoproducts were between 270 and 295 nm. This human endonuclease therefore has a similar ultraviolet substrate specificity to endonuclease III.