Due to its physical, chemical, and structural properties, oakwood is widely used in the production of barrels for wine ageing. When in contact with the wine, oak continuously releases aromatic compounds such as lignin, tannin, and cellulose to the liquid. Due to the release process, oak loses its characteristic aromatic compounds in time; hence, the flavour that it gives to the enclosed wine decreases for repeated wine refills and a barrel replacement is required.
View Article and Find Full Text PDFSunscreen preparations containing 5-methoxypsoralen at 25 micrograms/ml and 50 micrograms/ml, and the appropriate vehicle only, sunscreen only, and 5-methoxypsoralen only controls, were assessed for tumorigenic potential in hairless albino mice exposed to solar simulated radiation for a period of 44-46 weeks. Some animals were observed for a 15 week post-irradiation period. A wide range of statistical analyses has shown that, during the course of irradiation, the inclusion of sunscreens eliminates the enhancement of phototumorigenesis and malignancy that is normally observed with 5-methoxypsoralen.
View Article and Find Full Text PDFA double-blind controlled trial of low-dose prophylactic oral psoralen photochemotherapy (PUVA) and ultraviolet-B (UVB) irradiation therapy was undertaken from April to September 1983 in 42 patients with polymorphic light eruption (PLE). Patients were randomly allocated to three groups, PUVA with oral 8-methoxypsoralen (8-MOP), UVB with oral placebo, and control low-dose UVA with oral placebo. The initial dose given to each active treatment group was a third of the predetermined minimal phototoxic or erythema dose, followed three times weekly for 6 weeks by doses incremented by an eighth on each occasion in the PUVA group and by a seventh in the UVB group.
View Article and Find Full Text PDFA double-blind controlled trial of oral hydroxychloroquine (HC) treatment in polymorphic light eruption (PLE) was completed in 13 patients on active treatment and 15 on placebo during June, July and August 1982. HC dose was 400 mg daily for the first month and 200 mg daily thereafter. Exposure to ambient solar ultraviolet radiation (UVR) was monitored throughout the trial by polysulphone film lapel badges.
View Article and Find Full Text PDFArch Dermatol
October 1985
A 68-year-old man with apparently light-exacerbated erythematous cutaneous plaques on his face and on the dorsa of his hands was found to have late-onset erythropoietic protoporphyria, diabetes mellitus, and hyperlipidemia. Extensive deposits of material that stained with periodic acid-Schiff were present in the lesional dermis. Monospecific antibody studies showed this material to be mainly type IV collagen.
View Article and Find Full Text PDFHairless albino mice were painted with 8-methoxypsoralen (8-MOP) and exposed to solar simulated radiation (SSR) for 0, 3 or 6 weeks and subsequently treated with the promoter 12-O-tetradecanoylphorbol-13-acetate (TPA). TPA was highly tumourigenic in non-pretreated mice. Pretreatment with 8-MOP + SSR did not increase this level of tumorigenesis.
View Article and Find Full Text PDFA comparison of the photosensitizing ability of a variety of porphyrins for photohaemolysis gives the following order of activity: protoporphyrin greater than deuteroporphyrin, mesoporphyrin, haematoporphyrin dimethyl ester much greater than haematoporphyrin diacetate, haematoporphyrin greater than haematoporphyrin monoacetate, coproporphyrin III, haematoporphyrin derivative, coproporphyrin III tetramethyl ester greater than uroporphyrin I, meso-tetra-(N-methyl-4-pyridinium)porphyrin tetratoluene-p-sulphonate, meso-tetra-(p-carboxyphenyl)porphyrin, protoporphyrin dimethyl ester, meso-tetra-(p-hydroxy-sulphonylphenyl)porphyrin tetrasodium salt, uroporphyrin III, deuteroporphyrin-3,8-disulphonic acid and protohaemin. The results for the metal-free porphyrins are rationalized in terms of solubility and partition properties, and a model is proposed for the incorporation of amphipathic porphyrins into the membrane lipid bilayer. Experiments with erythrocytes from patients with erythropoeitic protoporphyria and with normal erythrocytes to which porphyrin was added in a deuterium oxide medium do not lead to an increase in the rate of photohaemolysis.
View Article and Find Full Text PDFSeven patients with porphyria cutanea tarda received a total of ten courses of low-dose oral chloroquine therapy (125 mg chloroquine phosphate twice weekly). Patients were treated for a mean 14.9 months during which time all went into clinical and biochemical remission.
View Article and Find Full Text PDFHairless albino mice have been treated with topically applied 8-methoxypsoralen and 5-methoxypsoralen at two concentrations and exposed to solar simulated radiation. Both these compounds significantly increased the incidence of cutaneous tumours when compared with controls irradiated after treatment with vehicle. This effect was related to psoralen concentration and at the two concentrations investigated there was no significant difference between the compounds.
View Article and Find Full Text PDFFourteen patients suffering from actinic prurigo were treated with thalidomide. Eleven patients showed lasting improvement on the drug and three of these remained symptom-free after discontinuing therapy. No major side-effects were observed.
View Article and Find Full Text PDFFibroblasts cultured from six patients with actinic reticuloid (AR) showed striking cytopathic changes and inhibition of RNA synthesis after exposure to near-ultraviolet radiation that had no effect on normal and other photosensitive cell strains, such as those of xeroderma pigmentosum and Bloom syndrome. An abnormal pattern of DNA fragmentation was observed after doses insufficient to cause cytopathic effects. These results suggest a cellular defect in the prevention or repair of some damage caused by free radicals and other photoproducts.
View Article and Find Full Text PDFA series of controlled trials of treatments for polymorphic light eruption (PLE) with oral beta-carotene, ketoprofen and chloroquine, and topical benzimidazole sunscreen cream is described. Clinical features were recorded using diary cards filled out by the patients, and exposure to UVR was measured individually in all patients with film badges. Symptoms were found to be dependent on exposure.
View Article and Find Full Text PDFThe production of the sunburn cell by UV-A radiation and topical psoralens in hairless mouse epidermis has been studied. It has been shown that the appearance of this cell is dependent on the dose of both UV-A radiation and of the psoralen. The time-course with 8-methoxypsoralen has peak sunburn cell numbers at 28 hr postirradiation.
View Article and Find Full Text PDFThe UVR radiometry of a long-term mouse photocarcinogenesis project is described. The methods used were (a) a phototherapy (UV-A) radiometer, (b) an electronic integrating dosimeter, (c) indirect spectroradiometry and (d) polysulphone and phenothiazine film badges for UV-B and UV-A respectively. The merits of the various methods are discussed.
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