Pub Date : 2001-12-01DOI: 10.1034/J.1600-0781.2001.170607.X
R. Mckenzie
{"title":"Ultraviolet radiation B (UVB)-induction of Leukaemia Inhibitory Factor (LIF) in human keratinocytes.","authors":"R. Mckenzie","doi":"10.1034/J.1600-0781.2001.170607.X","DOIUrl":"https://doi.org/10.1034/J.1600-0781.2001.170607.X","url":null,"abstract":"","PeriodicalId":20104,"journal":{"name":"Photodermatology, Photoimmunology and Photomedicine","volume":"55 1","pages":"284-285"},"PeriodicalIF":0.0,"publicationDate":"2001-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85238207","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-12-01DOI: 10.1034/J.1600-0781.2001.170604.X
H. An, J. Yoo, M. K. Lee, M. Shin, G. Rhie, J. Seo, J. Chung, H. Eun, K. Cho
Purpose: To establish whether the effect of fractionating radiation modifies the effects of ultraviolet (UV) radiation on epidermal melanocytes, we compared the clinical and histological effects of single high dose radiation against repeated intermediate to low dose radiation on epidermal melanocytes. Methods: Three minimal erythema UV doses (MED) were administered to three sites on the buttocks of healthy volunteers. One site was irradiated with 0.5 MED UV every day for 6 consecutive days, another site was irradiated with 1 MED UV every second day, and a third site received a single dose of radiation with 3 MED UV. The treatment was replicated on the other buttock. For the evaluation of UV-induced erythema and pigmentation, erythema and melanin indices were measured at 2 and 14 days post-irradiation. For purposes of histological evaluation, tissue specimens taken from each irradiated site at 2 and 14 days post-irradiation and were stained with monoclonal antibodies against Mel-5, HMB-45 and tyrosinase. Fontana-Masson silver staining, DOPA staining and split DOPA reactions were also performed. Results: At 14 days post-irradiation, UV radiation induced melanocyte activation, proliferation and melanogenesis in proportion to the radiation dose administered to each fraction. The most prominent responses were observed after single high doses of radiation. Conclusion: When the total administered dose is identical, fractionation of radiation dose diminishes the effects of UV radiation on epidermal melanocytes. Furthermore, long, uninterrupted doses of UV radiation were found to more effective in inducing melanogenesis and melanocyte activation.
目的:为了确定分次辐射是否改变了紫外线(UV)辐射对表皮黑色素细胞的影响，我们比较了单次高剂量辐射和多次中、低剂量辐射对表皮黑色素细胞的临床和组织学影响。方法:对健康志愿者臀部3个部位施用3次微红斑紫外线剂量(MED)。一个部位每天接受0.5 MED UV照射，连续6天，另一个部位每隔一天接受1 MED UV照射，第三个部位接受3 MED UV单剂量照射。在另一个臀部也进行了同样的治疗。在照射后第2天和第14天测量红斑和黑色素指数，以评估紫外线诱导的红斑和色素沉着。为了进行组织学评估，在照射后2天和14天从每个照射部位取组织标本，并用Mel-5、HMB-45和酪氨酸酶单克隆抗体进行染色。同时进行Fontana-Masson银染色、DOPA染色和分裂DOPA反应。结果:在照射后14天，紫外线辐射诱导黑素细胞活化、增殖和黑素形成与给药剂量成正比。在单次高剂量辐射后观察到最显著的反应。结论:在给药总剂量相同的情况下，照射剂量的分段减小了紫外线照射对表皮黑色素细胞的影响。此外，长时间不间断的紫外线辐射被发现更有效地诱导黑素生成和黑素细胞活化。
{"title":"Single dose radiation is more effective for the UV-induced activation and proliferation of melanocytes than fractionated dose radiation","authors":"H. An, J. Yoo, M. K. Lee, M. Shin, G. Rhie, J. Seo, J. Chung, H. Eun, K. Cho","doi":"10.1034/J.1600-0781.2001.170604.X","DOIUrl":"https://doi.org/10.1034/J.1600-0781.2001.170604.X","url":null,"abstract":"Purpose: To establish whether the effect of fractionating radiation modifies the effects of ultraviolet (UV) radiation on epidermal melanocytes, we compared the clinical and histological effects of single high dose radiation against repeated intermediate to low dose radiation on epidermal melanocytes. \u0000 \u0000 \u0000 \u0000Methods: Three minimal erythema UV doses (MED) were administered to three sites on the buttocks of healthy volunteers. One site was irradiated with 0.5 MED UV every day for 6 consecutive days, another site was irradiated with 1 MED UV every second day, and a third site received a single dose of radiation with 3 MED UV. The treatment was replicated on the other buttock. For the evaluation of UV-induced erythema and pigmentation, erythema and melanin indices were measured at 2 and 14 days post-irradiation. For purposes of histological evaluation, tissue specimens taken from each irradiated site at 2 and 14 days post-irradiation and were stained with monoclonal antibodies against Mel-5, HMB-45 and tyrosinase. Fontana-Masson silver staining, DOPA staining and split DOPA reactions were also performed. \u0000 \u0000 \u0000 \u0000Results: At 14 days post-irradiation, UV radiation induced melanocyte activation, proliferation and melanogenesis in proportion to the radiation dose administered to each fraction. The most prominent responses were observed after single high doses of radiation. \u0000 \u0000 \u0000 \u0000Conclusion: When the total administered dose is identical, fractionation of radiation dose diminishes the effects of UV radiation on epidermal melanocytes. Furthermore, long, uninterrupted doses of UV radiation were found to more effective in inducing melanogenesis and melanocyte activation.","PeriodicalId":20104,"journal":{"name":"Photodermatology, Photoimmunology and Photomedicine","volume":"19 1","pages":"266-271"},"PeriodicalIF":0.0,"publicationDate":"2001-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82522301","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-12-01DOI: 10.1034/J.1600-0781.2001.170603.X
K. Danno, N. Mori, K. Toda, Takashi Kobayashi, A. Utani
Background/Aims: Several physical agents such as low-energy lasers have been used in the treatment of chronic skin ulcers. This study was performed to investigate potential effects of a newly-developed, specific near-infrared light source on wound repair. Methods: Cultured human keratinocytes, endothelial cells and fibroblasts were exposed to the light, and the production of transforming growth factor (TGF)-β1 and matrix metalloproteinase (MMP)-2 was examined by enzyme immunoassay, zymography and reverse transcription polymerase chain reaction. Incisional wounds were created in ICR and db/db diabetic mice and the effect of irradiation on wound closure was followed photographically. Results: The TGF-β1 and MMP-2 content of the medium of cultured cells was significantly elevated after irradiation. The amount of MMP-2 mRNA extracted from irradiated fibroblasts was also upregulated. Negative results in thermal controls suggested that the action of the light was athermic in nature. In animal models, the rate of wound closure was significantly accelerated by repeated exposures. Conclusion: Near-infrared irradiation potentially enhances the wound healing process, presumably by its biostimulatory effects.
{"title":"Near-infrared irradiation stimulates cutaneous wound repair: laboratory experiments on possible mechanisms","authors":"K. Danno, N. Mori, K. Toda, Takashi Kobayashi, A. Utani","doi":"10.1034/J.1600-0781.2001.170603.X","DOIUrl":"https://doi.org/10.1034/J.1600-0781.2001.170603.X","url":null,"abstract":"Background/Aims: Several physical agents such as low-energy lasers have been used in the treatment of chronic skin ulcers. This study was performed to investigate potential effects of a newly-developed, specific near-infrared light source on wound repair. \u0000 \u0000 \u0000 \u0000Methods: Cultured human keratinocytes, endothelial cells and fibroblasts were exposed to the light, and the production of transforming growth factor (TGF)-β1 and matrix metalloproteinase (MMP)-2 was examined by enzyme immunoassay, zymography and reverse transcription polymerase chain reaction. Incisional wounds were created in ICR and db/db diabetic mice and the effect of irradiation on wound closure was followed photographically. \u0000 \u0000 \u0000 \u0000Results: The TGF-β1 and MMP-2 content of the medium of cultured cells was significantly elevated after irradiation. The amount of MMP-2 mRNA extracted from irradiated fibroblasts was also upregulated. Negative results in thermal controls suggested that the action of the light was athermic in nature. In animal models, the rate of wound closure was significantly accelerated by repeated exposures. \u0000 \u0000 \u0000 \u0000Conclusion: Near-infrared irradiation potentially enhances the wound healing process, presumably by its biostimulatory effects.","PeriodicalId":20104,"journal":{"name":"Photodermatology, Photoimmunology and Photomedicine","volume":"29 1","pages":"261-265"},"PeriodicalIF":0.0,"publicationDate":"2001-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86168963","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-12-01DOI: 10.1034/J.1600-0781.2001.170601.X
E. Thieden, M. Ågren, H. Wulf
Background/Aim: The aim of this study was to quantify ultraviolet radiation (UVR) exposure of fully employed indoor workers during a Working Period and a Holiday Period in the summer months. A further aim was to investigate the correlation between individual personal UVR dosimeter reading and self-reported data in a diary about sun exposure habits and to investigate whether skin type, age and gender influence sun exposure. Methods: The solar UVR, in standard erythema doses (SED) measured by UV sensitive spore-film filter type personal dosimeters (VioSpor®), and sun exposure diaries were compared. The study included 44 healthy Danish adult indoor workers during a Working Period of a mean of 13 days and a Holiday Period of a mean of 17 days from June to September. Results: The individual total UVR exposure correlated significantly (P<0.001) in both the Holiday and Working Periods with individual total hours spent outdoors from 07:00 to 19:00 and with skin area exposure hours. There was no significant correlation between sun exposure dose and gender, age or skin type I-IV, or between the individual solar exposure dose in the Working and the Holiday Period. However, subjects with UVR exposures in the upper quartile spent their Holiday Period in Southern Europe, and/or had been more than the mean time outdoors at the beach/sea and/or between 12:00 and 15:00. Subjects with UVR exposure in the lower quartiles spent their holidays in Denmark or Northern Europe and did not stay at the beach at all. They received an average solar UVR dose which was 22% of ambient in Denmark in the same period while subjects having their holidays in Southern Europe received as much as 90% of the ambient dose in Denmark. Conclusions: Despite information campaigns to avoid the midday sun, on average 35% of the recorded hours outdoors were spent between 12:00 and 15:00 in the Holiday Period. Total hours outdoors give the best estimate of the total sun exposure dose. Registration in a diary of total hours outdoors and whether the Holiday Period was in Northern or Southern Europe can be used to predict the solar exposure dose in a Holiday Period of a few weeks.
{"title":"Solar UVR exposures of indoor workers in a Working and a Holiday Period assessed by personal dosimeters and sun exposure diaries.","authors":"E. Thieden, M. Ågren, H. Wulf","doi":"10.1034/J.1600-0781.2001.170601.X","DOIUrl":"https://doi.org/10.1034/J.1600-0781.2001.170601.X","url":null,"abstract":"Background/Aim: The aim of this study was to quantify ultraviolet radiation (UVR) exposure of fully employed indoor workers during a Working Period and a Holiday Period in the summer months. A further aim was to investigate the correlation between individual personal UVR dosimeter reading and self-reported data in a diary about sun exposure habits and to investigate whether skin type, age and gender influence sun exposure. \u0000 \u0000 \u0000 \u0000Methods: The solar UVR, in standard erythema doses (SED) measured by UV sensitive spore-film filter type personal dosimeters (VioSpor®), and sun exposure diaries were compared. The study included 44 healthy Danish adult indoor workers during a Working Period of a mean of 13 days and a Holiday Period of a mean of 17 days from June to September. \u0000 \u0000 \u0000 \u0000Results: The individual total UVR exposure correlated significantly (P<0.001) in both the Holiday and Working Periods with individual total hours spent outdoors from 07:00 to 19:00 and with skin area exposure hours. There was no significant correlation between sun exposure dose and gender, age or skin type I-IV, or between the individual solar exposure dose in the Working and the Holiday Period. However, subjects with UVR exposures in the upper quartile spent their Holiday Period in Southern Europe, and/or had been more than the mean time outdoors at the beach/sea and/or between 12:00 and 15:00. Subjects with UVR exposure in the lower quartiles spent their holidays in Denmark or Northern Europe and did not stay at the beach at all. They received an average solar UVR dose which was 22% of ambient in Denmark in the same period while subjects having their holidays in Southern Europe received as much as 90% of the ambient dose in Denmark. \u0000 \u0000 \u0000 \u0000Conclusions: Despite information campaigns to avoid the midday sun, on average 35% of the recorded hours outdoors were spent between 12:00 and 15:00 in the Holiday Period. Total hours outdoors give the best estimate of the total sun exposure dose. Registration in a diary of total hours outdoors and whether the Holiday Period was in Northern or Southern Europe can be used to predict the solar exposure dose in a Holiday Period of a few weeks.","PeriodicalId":20104,"journal":{"name":"Photodermatology, Photoimmunology and Photomedicine","volume":"24 1","pages":"249-255"},"PeriodicalIF":0.0,"publicationDate":"2001-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75125471","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-12-01DOI: 10.1034/J.1600-0781.2001.170606.X
R. Sayre, J. Stanfield, Andrew J. Bush, Dennis L. Lott
Background: The COLIPA standard for solar simulators permits a range of spectral filtration. Published studies comparing the SPFs of sunscreen formulas show that a range of SPFs is generally expected between laboratories. Specifically, three studies determining the SPFs of sunscreen standards have been performed in a series of laboratories and differences exceeding 50% have been reported. No studies to date have specifically examined potential differences in performance of Standard Sunscreen Test Formulas with varying solar simulator spectra within the permitted range of optical filtration. Methods: In a paired clinical trial, two SPF standard sunscreen formulas were tested using two solar simulators that complied with the COLIPA standard for solar simulators but were filtered differently. One solar simulator was filtered as supplied by the manufacturer and delivered a high percentage of UVB; the other solar simulator was modified by removing the visible absorbing filter to deliver energy more closely resembling sunlight in the UVA-1 part of the spectrum, with a lower percentage of UVB. Results and Conclusion: The result was that the SPF of each standard sunscreen was almost 50% greater with the unmodified solar simulator than with the modified solar simulator. In vitro evaluation of the sunscreen standards predicted similar differences due to the spectral differences of the solar simulators, which appears to rule out reciprocity failure. However, reciprocity failure of the control MEDs was observed. The total intensity of the modified lamp was approximately 3 times that of the unmodified lamp.
{"title":"Sunscreen standards tested with differently filtered solar simulators.","authors":"R. Sayre, J. Stanfield, Andrew J. Bush, Dennis L. Lott","doi":"10.1034/J.1600-0781.2001.170606.X","DOIUrl":"https://doi.org/10.1034/J.1600-0781.2001.170606.X","url":null,"abstract":"Background: The COLIPA standard for solar simulators permits a range of spectral filtration. Published studies comparing the SPFs of sunscreen formulas show that a range of SPFs is generally expected between laboratories. Specifically, three studies determining the SPFs of sunscreen standards have been performed in a series of laboratories and differences exceeding 50% have been reported. No studies to date have specifically examined potential differences in performance of Standard Sunscreen Test Formulas with varying solar simulator spectra within the permitted range of optical filtration. \u0000 \u0000Methods: In a paired clinical trial, two SPF standard sunscreen formulas were tested using two solar simulators that complied with the COLIPA standard for solar simulators but were filtered differently. One solar simulator was filtered as supplied by the manufacturer and delivered a high percentage of UVB; the other solar simulator was modified by removing the visible absorbing filter to deliver energy more closely resembling sunlight in the UVA-1 part of the spectrum, with a lower percentage of UVB. \u0000 \u0000Results and Conclusion: The result was that the SPF of each standard sunscreen was almost 50% greater with the unmodified solar simulator than with the modified solar simulator. In vitro evaluation of the sunscreen standards predicted similar differences due to the spectral differences of the solar simulators, which appears to rule out reciprocity failure. However, reciprocity failure of the control MEDs was observed. The total intensity of the modified lamp was approximately 3 times that of the unmodified lamp.","PeriodicalId":20104,"journal":{"name":"Photodermatology, Photoimmunology and Photomedicine","volume":"56 1","pages":"278-283"},"PeriodicalIF":0.0,"publicationDate":"2001-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75553954","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-12-01DOI: 10.1034/J.1600-0781.2001.170602.X
M. Wintzen, Dagmar M. J. D. Ostijn, Marloes CA Polderman, Saskia le Cessie, J. Peter H. Burbach, B. J. Vermeer
UVA-1. Plasma ACTH-IR was monitored in parallel. Results: Overall, plasma levels of bE-IR and ACTHIR showed no significant changes during the experiment, indicating that these peptides are not influenced by single or repeated exposures to UVR of different wavelengths. Conclusion: On the basis of these results, the skin does not appear to contribute significantly to the levels of circulating bE or ACTH. These data offer no support for the hypothesis that exposure to UVR leads to an increased concentration of circulating bE, which could contribute to the feeling of well-being that often accompanies sun-bathing.
{"title":"Total body exposure to ultraviolet radiation does not influence plasma levels of immunoreactive beta-endorphin in man.","authors":"M. Wintzen, Dagmar M. J. D. Ostijn, Marloes CA Polderman, Saskia le Cessie, J. Peter H. Burbach, B. J. Vermeer","doi":"10.1034/J.1600-0781.2001.170602.X","DOIUrl":"https://doi.org/10.1034/J.1600-0781.2001.170602.X","url":null,"abstract":"UVA-1. Plasma ACTH-IR was monitored in parallel. Results: Overall, plasma levels of bE-IR and ACTHIR showed no significant changes during the experiment, indicating that these peptides are not influenced by single or repeated exposures to UVR of different wavelengths. Conclusion: On the basis of these results, the skin does not appear to contribute significantly to the levels of circulating bE or ACTH. These data offer no support for the hypothesis that exposure to UVR leads to an increased concentration of circulating bE, which could contribute to the feeling of well-being that often accompanies sun-bathing.","PeriodicalId":20104,"journal":{"name":"Photodermatology, Photoimmunology and Photomedicine","volume":"16 1","pages":"256-260"},"PeriodicalIF":0.0,"publicationDate":"2001-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88671850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-10-01DOI: 10.1034/J.1600-0781.2001.170503.X
K. H. Park, H. Choi, D. Jang, Yong Park, Kyung-Woo Park
Purpose: This study was performed to determine the effect of UV radiation on the activation of apoptosis regulatory proteins using cultured human melanoma cells.Methods: G361 lightly pigmented melanoma cells were irradiated with increasing doses of UVB and analyzed for an apoptotic mechanism using a cell viability test, TEM, FACS, and western blotting analysis.Results: TEM and FACS showed apoptotic features of cell death after UVB irradiation. Western blotting disclosed downregulation of Bcl-2 and the activation of caspase-9. Caspase-8, a downstream molecule of Fas/FasL interaction, was also activated. The activation of downstream molecules of both caspase-8 and caspase-9 was also demonstrated.Conclusion: Our data showed that the regulation of the Bcl-2 family and caspase-8 may work together to activate a caspase-3 mediated apoptotic pathway following UVB irradiation of cultured human melanoma cells.
{"title":"Downregulation of Bcl-2 and activation of caspase-8 in the UVB-induced apoptosis of a cultured human melanoma cell line.","authors":"K. H. Park, H. Choi, D. Jang, Yong Park, Kyung-Woo Park","doi":"10.1034/J.1600-0781.2001.170503.X","DOIUrl":"https://doi.org/10.1034/J.1600-0781.2001.170503.X","url":null,"abstract":"Purpose: This study was performed to determine the effect of UV radiation on the activation of apoptosis regulatory proteins using cultured human melanoma cells.Methods: G361 lightly pigmented melanoma cells were irradiated with increasing doses of UVB and analyzed for an apoptotic mechanism using a cell viability test, TEM, FACS, and western blotting analysis.Results: TEM and FACS showed apoptotic features of cell death after UVB irradiation. Western blotting disclosed downregulation of Bcl-2 and the activation of caspase-9. Caspase-8, a downstream molecule of Fas/FasL interaction, was also activated. The activation of downstream molecules of both caspase-8 and caspase-9 was also demonstrated.Conclusion: Our data showed that the regulation of the Bcl-2 family and caspase-8 may work together to activate a caspase-3 mediated apoptotic pathway following UVB irradiation of cultured human melanoma cells.","PeriodicalId":20104,"journal":{"name":"Photodermatology, Photoimmunology and Photomedicine","volume":"222 1","pages":"218-222"},"PeriodicalIF":0.0,"publicationDate":"2001-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77582876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-10-01DOI: 10.1034/J.1600-0781.2001.170502.X
S. E. Whitmore, C. Potten, C. Chadwick, P. Strickland, W. Morison
Background/Aims: Photoreactivating light (PRL) after ultraviolet radiation (UVR) exposure causes photoreversal of cyclobutane pyrimidine dimers through the activation of photolyase. Although photoreversal has been demonstrated in the ‘three kingdoms of life,’ its existence in man remains controversial. We sought evidence for photoreversal in man. Methods and Results: Seven subjects were spot-irradiated at two sites with 4 minimal erythema doses (MED) of solar-simulating UVR. Of the two sites, one was then immediately exposed to a PRL source. Epidermal biopsies were taken immediately after exposure. No significant difference in the quantity of pyrimidine dimers was detected comparing the ‘UVR only’ site to the ‘UVR, PRL-exposed’ site. Biopsies were repeated 24 h later and no significant difference in p53 protein expression or dendritic cell number was detected. However, the ‘UVR, PRL-exposed’ site showed a greater reduction in pyrimidine dimer quantity. Conclusions: We found no evidence for a direct effect of PRL causing photoreversal of UVR-induced pyrimidine dimers in man. Our results do, however, suggest that some indirect effect of PRL may enhance pyrimidine dimer repair in the 24-h period following UVR exposure.
{"title":"Effect of photoreactivating light on UV radiation-induced alterations in human skin","authors":"S. E. Whitmore, C. Potten, C. Chadwick, P. Strickland, W. Morison","doi":"10.1034/J.1600-0781.2001.170502.X","DOIUrl":"https://doi.org/10.1034/J.1600-0781.2001.170502.X","url":null,"abstract":"Background/Aims: Photoreactivating light (PRL) after ultraviolet radiation (UVR) exposure causes photoreversal of cyclobutane pyrimidine dimers through the activation of photolyase. Although photoreversal has been demonstrated in the ‘three kingdoms of life,’ its existence in man remains controversial. We sought evidence for photoreversal in man. \u0000 \u0000 \u0000 \u0000Methods and Results: \u0000 \u0000Seven subjects were spot-irradiated at two sites with 4 minimal erythema doses (MED) of solar-simulating UVR. Of the two sites, one was then immediately exposed to a PRL source. Epidermal biopsies were taken immediately after exposure. No significant difference in the quantity of pyrimidine dimers was detected comparing the ‘UVR only’ site to the ‘UVR, PRL-exposed’ site. Biopsies were repeated 24 h later and no significant difference in p53 protein expression or dendritic cell number was detected. However, the ‘UVR, PRL-exposed’ site showed a greater reduction in pyrimidine dimer quantity. \u0000 \u0000 \u0000 \u0000Conclusions: We found no evidence for a direct effect of PRL causing photoreversal of UVR-induced pyrimidine dimers in man. Our results do, however, suggest that some indirect effect of PRL may enhance pyrimidine dimer repair in the 24-h period following UVR exposure.","PeriodicalId":20104,"journal":{"name":"Photodermatology, Photoimmunology and Photomedicine","volume":"3 1","pages":"213-217"},"PeriodicalIF":0.0,"publicationDate":"2001-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78596581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2001-10-01DOI: 10.1034/J.1600-0781.2001.170501.X
D. Yarosh
Liposomes are microscopic spheres, usually composed of amphiphilic phospholipids. They may be useful without skin penetration if they simply protect or sequester compounds that would otherwise be unstable in the formulation. Liposomes that remain on the skin surface are useful as light-absorbers, agents to deliver color or sunscreens, or as depots for timed-release. Liposomes that penetrate the stratum corneum have the potential to interact with living tissue. Topically applied liposomes can either mix with the stratum corneum lipid matrix or penetrate the stratum corneum by exploiting the lipid-water interface of the intercellular matrix. There are at least four major routes of entry into the skin: pores, hair follicles, columnular spaces and the lipid:water matrix between squames. A major force driving liposome penetration is the water gradient, and flexible liposomes are best able to exploit these delivery opportunities. Some liposomes release their contents extracellularly. Topical application of photosensitizers may be enhanced by encapsulation in liposomes. Higher and longer-lasting drug concentrations may be produced in localized areas of skin, particularly at disease sites where the stratum corneum and the skin barrier function are disrupted. The liposome membrane should be designed to capture lipophilic drugs in the membrane or hydrophilic drugs in the interior. Other types of liposomes can be engineered to be taken up by cells. Once inside cells, the lysosomal sac and clatherin-coated pit are the dead-end destinations for liposomes unless an escape path has been engineered into the liposome. A novel method has been developed to allow delivery into cells of the skin, by escape from the lysosomal sac. These liposomes have been used to topical deliver active DNA repair enzymes from liposomes into epidermal cells and to enhance DNA repair of UV-irradiated skin. From these studies a tremendous amount has been learned about the relationship of DNA damage and skin cancer. Both mutations and immunosuppression appear to be essential to skin cancer and both are induced by DNA damage. DNA damage produces immediate effects by inducing the expression of cytokines, which means that DNA damage can induce signaling in neighboring, undamaged cells. The repair of only a fraction of the DNA damage has a disproportionate effect on the biological responses, clearly demonstrating that not all DNA damage is equivalent. This technology demonstrates that biologically active proteins can be delivered into the cells of skin, and opens up a new field of correcting or enhancing skin cell metabolism to improve human health.
{"title":"Liposomes in investigative dermatology.","authors":"D. Yarosh","doi":"10.1034/J.1600-0781.2001.170501.X","DOIUrl":"https://doi.org/10.1034/J.1600-0781.2001.170501.X","url":null,"abstract":"Liposomes are microscopic spheres, usually composed of amphiphilic phospholipids. They may be useful without skin penetration if they simply protect or sequester compounds that would otherwise be unstable in the formulation. Liposomes that remain on the skin surface are useful as light-absorbers, agents to deliver color or sunscreens, or as depots for timed-release. Liposomes that penetrate the stratum corneum have the potential to interact with living tissue. Topically applied liposomes can either mix with the stratum corneum lipid matrix or penetrate the stratum corneum by exploiting the lipid-water interface of the intercellular matrix. There are at least four major routes of entry into the skin: pores, hair follicles, columnular spaces and the lipid:water matrix between squames. A major force driving liposome penetration is the water gradient, and flexible liposomes are best able to exploit these delivery opportunities. Some liposomes release their contents extracellularly. Topical application of photosensitizers may be enhanced by encapsulation in liposomes. Higher and longer-lasting drug concentrations may be produced in localized areas of skin, particularly at disease sites where the stratum corneum and the skin barrier function are disrupted. The liposome membrane should be designed to capture lipophilic drugs in the membrane or hydrophilic drugs in the interior. Other types of liposomes can be engineered to be taken up by cells. Once inside cells, the lysosomal sac and clatherin-coated pit are the dead-end destinations for liposomes unless an escape path has been engineered into the liposome. A novel method has been developed to allow delivery into cells of the skin, by escape from the lysosomal sac. These liposomes have been used to topical deliver active DNA repair enzymes from liposomes into epidermal cells and to enhance DNA repair of UV-irradiated skin. From these studies a tremendous amount has been learned about the relationship of DNA damage and skin cancer. Both mutations and immunosuppression appear to be essential to skin cancer and both are induced by DNA damage. DNA damage produces immediate effects by inducing the expression of cytokines, which means that DNA damage can induce signaling in neighboring, undamaged cells. The repair of only a fraction of the DNA damage has a disproportionate effect on the biological responses, clearly demonstrating that not all DNA damage is equivalent. This technology demonstrates that biologically active proteins can be delivered into the cells of skin, and opens up a new field of correcting or enhancing skin cell metabolism to improve human health.","PeriodicalId":20104,"journal":{"name":"Photodermatology, Photoimmunology and Photomedicine","volume":"24 1","pages":"203-212"},"PeriodicalIF":0.0,"publicationDate":"2001-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88348336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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