• Title/Summary/Keyword: minimal erythema dose

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Inhibitory Effect of PME88 MelonSOD on the Ultraviolet-Induced Photo-aging (PME88 멜론SOD의 자외선으로 인한 피부 광노화 억제 효과)

  • Cho, Se-Haeng
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.38 no.4
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    • pp.401-408
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    • 2009
  • PME88 (gliadin-combined) melon superoxide dismutase (SOD) is known to promote the production of the body‘s own natural antioxidants including superoxide dismutase, catalase and glutathione peroxidase. In this study, we investigated the inhibitory effects of PME88 melonSOD on the ultraviolet-induced photo-aging by the evolution of minimal erythemal dose (MED), erythema quotation and spectrocolorimetric measurements of erythema. The analysis of the evolution of the MED showed a significant increase 28 days after the daily taken of the PME88 melonSOD. The analysis of the erythema quotation showed that on D29, for the dose 1.25 MED, erythema intensity is significantly higher for placebo group than for PME88 melonSOD group. At doses 0.64 MED$_{D14}$, 0.80 MED$_{D14}$ and 1 MED$_{D14}$ the value of parameter $a^*$ (the most sensitive to the colour changes bound to the variations of blood flow. It permits to assess the evolution of erythema) is significantly higher for placebo group. No significant difference has been observed between groups (PME88 melonSOD and placebo) on the evolution of the number and consistency of feces after 4 weeks of treatment. No intolerance has been observed during the 4 weeks of treatment. These results mean that PME88 melonSOD as a dietary supplement could be useful to attenuate ultraviolet-induced skin photo-aging.

Characteristic of MED measurement Value of Trial Subjects from Ultraviolet Irradiation (자외선 조사 피험자의 MED 측정 값의 특성에 관한 연구)

  • Suk, Jang Mi;Park, Shin Young;Choi, Mi Ra;An, Song Yi;Kim, In Soo;Kim, Beom Joon;Park, Jin O;Jung, Sang Wook
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.39 no.3
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    • pp.251-257
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    • 2013
  • In this study, ultraviolet protection factor (Sun Protection Factor, SPF) was investigated to provide basic data for subject safety and research of ultraviolet (UV) irradiation test in the future. Trial subjects (395 people) of skin type I, II, and III were evaluated according to skin type standard table. After measuring the skin color using a colorimeter, ITA (Individual Typology Angle) value was calculated. Subjects with 28 and above ITA value were positioned comfortably to be UV irradiated for 60 s and erythema was evaluated 24 hours after application. MED (Minimal Erythema Dose) was investigated where the minimal amount of erythema existed among UVB irradiated area. Statistical analysis was investigated using Statistical Package the Social Sciences program. As a result, the darker skin color results in the higher MED value since the higher skin type number results increased MED value and female has higher MED value than male since female has darker skin type than male. There was no relation between MED difference by ages in all different ages. However, it is hard to draw a conclusion as above since the number of subjects were not sufficient to support statistical significance for MED values by different ages. However, MED values by skin types obtained through this study can be used as a standard when MED value is expected to evaluate efficacy of sunscreen product and as basic data for further safety of clinical researches.

Effect of Electrical Stimulation Level on Quantitative Sensory Test Induced Erythema by UV Radiation (전기자극수준이 자외선에 의한 홍반의 정량적 감각검사에 미치는 효과)

  • Kim, Su-Hyon;Kim, Hyun-Jin
    • Journal of the Korean Academy of Clinical Electrophysiology
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    • v.10 no.2
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    • pp.1-6
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    • 2012
  • Purpose : This study is to investigate the modulatory effects to the ultraviolet induced erythema of pain processing system. Methods : Thirty six healthy volunteers were divided into none treatment group (n=6), indomethacine group (n=6), subsensory level electrical stimulation group (n=6), sensory level electrical stimulation group (n=6), motor level electrical stimulation group (n=6), noxious level electrical stimulation group (n=6). Subjects were induced erythema for three times minimal erythema dose (MED) at upper arm of dermatome C6 level. Each experimental group had mechanical pain threshold (MPT), electrical pain threshold (EPT), thermal pain threshold (TPT). Results : This study revealed that we observed that pain thresholds were significantly correlated with each other in pain processing system. The effect of electrical stimulation levels evaluates were shown to be significant differences pain control effect in electrical stimulation group (sensory, motor level electrical stimulation groups) more than indomethacine group, subsensory level and control group. Conclusion : In this study, it was found that the effect of ultraviolet induced erythema of pain control by modulatory electrical stimulation.

Effects of Ultraviolet Radiation on the Skin (자외선에 의한 피부반응)

  • Youn, Jail-Il
    • Journal of Radiation Protection and Research
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    • v.20 no.3
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    • pp.181-186
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    • 1995
  • UV irradiation causes a variety of biologic effects on the skin. These effects can be devided to acute reactuons and chronic reacxtions by duration of UV irradiation. Acute reactions are erythema reaction, pigment reactions and changes in epidermal thickness. Among them erythema reaction is most common and conspicuous acute effects of the skin. Upon exposure to sun or artificial UV soures, a faint redness response of skin may begin. Larger exposure causes sunburn reaction which is exaggerated erythema reactionassociated with pain, swelling, vesicle and dulla. Extent and time course of erythema reaction depend upon several factors including wavelength and dose of UVR, skin conditions likeas skin type, site, color, temperature, humidity and environmental factors. Evaluation of erythema erythema induced by UV irradiation is difficult to quantify. Degree of redness of skin are usually estimated by subjective visual evaluation. The lowest exposure dose required to protuce erythema is called minimal erythema dose (mod). Repeated exposures of UVR result in photaging skin. In this condition we can see wrinkling, skin atrophy, dilated blood vessels and keratoses. In sensitive persons photocarcinogenesis is can Be developed on exposed area of skin. Recently skin canser is increasing now in our country. An effective public education and photopreventive method must be developed.

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Relationship between UV-induced MED and Perfusion Value Assessed by Laser Doppler Perfusion Imager (Laser Doppler Perfusion Imager (LDPI)로 측정한 자외선 조사부위의 혈류량과 최소 홍반량(MED)과의 상관관계)

  • Kim, Nam-Soo;Lee, Kyung-Hoon
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.31 no.3 s.52
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    • pp.259-263
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    • 2005
  • The aim of the present study is to evaluate relationship between UV-induced MED and perfusion value assessed by Laser Doppler Perfusion Imager. In this study, A increasing linear relationship is seen between perfusion and dose (p<0.05). The dose-response curve show a steep slope in the case of lower MED values group after MED point, For higher MED group, increase with a gentle slope.

Development of a novel in vitro SPF evaluation method (새로운 in vitro SPF측정법 개발)

  • 오선진;김진준
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.21 no.2
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    • pp.57-72
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    • 1995
  • We have recently developed a novel in vitro SPF evaluation method with a high correlation coefficient (r=0.93) to in vivo SPF values(test sunscreen formulas : cress m, foundation). In this method, the in vitro SPF value was determined by the ratio of the time taken to achieve the minimal erythema dose with and without the sunscreens applied. We also reviewed the dilution and thin-layer methods for in vitro SPF evaluation, and investigated the relationship between irradiance(3$\times$10-3 2.5x 10-5W/cm2) and the degree of erythema. The degree of erythema was similar if t he radiation exposure(40mJ/cm2) was kept constant. It was obtained more than 0.90 correlation coefficient when it was compared the results by our new method with those from SPF-290 analyzer (Optometries, U.S.A.).

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"Beach Lifeguards' Sun Exposure and Sun Protection in Spain"

  • de Troya Martin, Magdalena;Sanchez, Nuria Blazquez;Garcia Harana, Cristina;Leiva, Ma Carmen Alarcon;Arjona, Jose Aguilera;Ruiz, Francisco Rivas;de Galvez Aranda, Ma Victoria
    • Safety and Health at Work
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    • v.12 no.2
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    • pp.244-248
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    • 2021
  • Background: Sunburn is the main avoidable cause of skin cancer. Beach lifeguards spend many hours exposed to the effects of solar radiation during their work day, precisely at times of the year when levels of solar irradiation are highest. The aim of this study is to quantify the risk to beach lifeguards of sun exposure. Methods: A descriptive cross-sectional study was carried out in the Western Costa del Sol, southern Spain, during the summer of 2018. The research subjects were recruited during a skin cancer prevention course for beach lifeguards. All participants were invited to complete a questionnaire on their habits, attitudes, and knowledge related to sun exposure. In addition, ten were specially monitored using personal dosimeters for three consecutive days, and the results were recorded in a photoprotection diary. A descriptive analysis (mean and standard deviation for the quantitative variables) was performed, and inter-group differences were evaluated using the Mann-Whitney U test. Results: Two hundred fifteen lifeguards completed the questionnaire, and 109 met the criteria for inclusion in this analysis. The mean age was 23.8 years (SD: 5.1), 78.0% were male, 71.5% were phototype III or IV (Fitzpatrick's phototype), and 77.1% had experienced at least one painful sunburn during the previous summer. The mean daily personal ultraviolet exposure per day, the minimal erythema dose, and the standard erythema dose, in J/m2, were 634.7 [standard deviation (SD): 356.2], 2.5 (SD: 1.4) and 6.35 (SD: 3.6), respectively. Conclusion: Beach lifeguards receive very high doses of solar radiation during the work day and experience correspondingly high rates of sunburn. Intervention strategies to modify their sun exposure behavior and working environment are necessary to reduce the risk of skin cancer for these workers and to promote early diagnosis of the disease.

Study on the MED of Koreans (한국인의 최소홍반량에 관한 연구)

  • 김진준;박문억
    • Proceedings of the SCSK Conference
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    • 1992.09a
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    • pp.36-45
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    • 1992
  • The dosal sites of 61 Koreans were exposed to increasing UVB doses in the 10mJ/$\textrm{cm}^2$ interval from 10mJ/$\textrm{cm}^2$ to 100mJ/$\textrm{cm}^2$ by solar-simulator, and at the 24hr after UV-B exposure we determined the first MED (Minimal Erythema Dose). For the precise measurements, we peformed the second exposures arround the first MED with 2.5mJ/$\textrm{cm}^2$ interval. The mean MED of all volunteers was 39.6 $\pm$ 15.7mJ/$\textrm{cm}^2$. As the distinction of sex, the means of male and female were 46.9 $\pm$ 18.1mJ/$\textrm{cm}^2$ and 31.5$\pm$8.5mJ/$\textrm{cm}^2$ respectively. According to the classification of skin type by Greiter. F.(1), the percent of skin type I to Ⅵ were 10.9%, 36.4%, 34.6%, 12.7%, 3.6%, and 1.8% respectively.

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Characteristics of Environmental Solar Ultraviolet Irradiance

  • Sasaki, Masako;Oyanagi, Takehiko;Takeshita, Shu
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.154-157
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    • 2002
  • Direct, continuous, and accurate measurements of solar ultraviolet irradiance (290-400 nm: UVR) have been carried out since 1990, by using both band-spectral ultraviolet-B (290-320 nm: UV-B) and ultraviolet-A (320-400 nm: UV-A) radiometers at Tokai University in Hiratsuka, Japan (35$^{\circ}$N, 139$^{\circ}$E). From our observations, the following findings are provided: 1) an increasing trend in solar UV -B from Oct. 1990 to Sept. 2000; 2) a regional comparison of solar UVR in Japan; 3) the distinct characteristics of UV-B and UV-A irradiance, such as diffuse property, daily and seasonal variation; and 4) human body protection against solar UVR. An increasing 10-year trend in global solar UV - B in Hiratsuka corresponded to a decrease in the total ozone amount measured at Tsukuba (36$^{\circ}$N, 140$^{\circ}$E), giving supportive evidence for a direct link between these two parameters. Furthermore, a strong correlation was found between solar UV-B and total ozone amount from results of UVR measurements at four Tokai University monitoring stations dispersed throughout Japan. Additional results revealed different diffuse properties in global solar UV and in global solar total (300-3000 nm: Total) irradiances. For example, in the global UVR, the diffuse component was dominant: about 80 % independent of weather, with more than 60 % of global UV-B, and more than 50% of global UV-A with even a cloudless clear sky. On the other hand, the portion of the diffuse in the global total irradiance was very low, less than 10 % on a cloudless clear day. Daily and seasonal variations of UV -B and UV -A irradiances were found to be quite different, because of the marked dependence of UV -B irradiance on the atmospheric ozone amount. Moreover, UV -B irradiance showed large daily and seasonal variations: the ratio between maximum and minimum irradiances was more than 5. In contrast, the variation in UV-A was small: the ratio between maximum and minimum was less than 2. Three important facts are proposed concerning solar UVR protection of the human body: 1) the personal minimal erythema dose (MED); 2) gender based difference in MED values; and 3) proper colors for UVR protective clothing.

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UV Sensitivity of Korean Skin and The Effects of Factors affecting SPF Determination (한국인 피부의 자외선 감수성과 SPF 측정치에 미치는 인자의 영향)

  • 이병곤
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.17 no.1
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    • pp.1-17
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    • 1991
  • Multiport-600 Solar SimulatorR is one of the most recent and convenient in-strument for evaluation of sun protection factor(SPF). In this study, we examined the practicability of the SPF determining system using Multiport -600 and the effects of several factors-light sources, seasons and experimental animals-on the minimal erythema dose(MED) and SPF. We also tested the UV sensitivity according to the sites of Korean people, And the ultraviolet radiation reaching the earth's surface In Seoul have been observed for one year. As a result of this study, the determinig system for SPF using Multiport-600 was proved to be a good system in accuracy and time-saving. The biological activity of fluorescence UV lamp of PUVA-800R was significantly higher than natural light or solar simulator with Xe arc lamp, and the determined MED became lower in inverse proportion to room temperature rise. Skin sensitivity by ultraviolet adiation was hights. in order \circled1 back \circled2 inns, upper arm \circled3 outer upper arm \circled4 foream. We also observed that UV radiation intensity was highest at noon in july and 1 sun burn unit(MED) was 28 minutes at that time.

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