The Experts below are selected from a list of 249 Experts worldwide ranked by ideXlab platform
Joanna Narbutt - One of the best experts on this subject based on the ideXlab platform.
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sunscreen applied at 2 mg cm 2 during a sunny holiday prevents Erythema a biomarker of ultraviolet radiation induced dna damage and suppression of acquired immunity
British Journal of Dermatology, 2019Co-Authors: Joanna Narbutt, Graham I. Harrison, Karl P. Lawrence, Kristi De Grys, K.a. Baczynska, Kylie A. Morgan, Michal Rogowskitylman, Irmina Olejniczakstaruch, Peter A. Philipsen, Angela TewariAbstract:BACKGROUND: Sun protection factor (SPF) is assessed with sunscreen applied at 2 mg cm-2 . People typically apply around 0·8 mg cm-2 and use sunscreen daily for holidays. Such use results in Erythema, which is a risk factor for skin cancer. OBJECTIVES: To determine (i) whether typical sunscreen use resulted in Erythema, epidermal DNA damage and photoimmunosuppression during a sunny holiday, (ii) whether optimal sunscreen use inhibited Erythema and (iii) whether Erythema is a biomarker for photoimmunosuppression in a laboratory study. METHODS: Holidaymakers (n = 22) spent a week in Tenerife (very high ultraviolet index) using their own sunscreens without instruction (typical sunscreen use). Others (n = 40) were given SPF 15 sunscreens with instructions on how to achieve the labelled SPF (sunscreen intervention). Personal ultraviolet radiation (UVR) exposure was monitored electronically as the standard Erythemal dose (SED) and Erythema was quantified. Epidermal cyclobutane pyrimidine dimers (CPDs) were determined by immunostaining, and immunosuppression was assessed by contact hypersensitivity (CHS) response. RESULTS: There was no difference between personal UVR exposure in the typical sunscreen use and sunscreen intervention groups (P = 0·08). The former had daily Erythema on five UVR-exposed body sites, increased CPDs (P < 0·001) and complete CHS suppression (20 of 22). In comparison, Erythema was virtually absent (P < 0·001) when sunscreens were used at ≥ 2 mg cm-2 . A laboratory study showed that 3 SED from three very different spectra suppressed CHS by around ~50%. CONCLUSIONS: Optimal sunscreen use prevents Erythema during a sunny holiday. Erythema predicts suppression of CHS (implying a shared action spectrum). Given that Erythema and CPDs share action spectra, the data strongly suggest that optimal sunscreen use will also reduce CPD formation and UVR-induced immunosuppression.
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Sunscreen applied at ≥ 2 mg cm-2 during a sunny holiday prevents Erythema, a biomarker of ultraviolet radiation-induced DNA damage and suppression of acquired immunity.
British Journal of Dermatology, 2018Co-Authors: Joanna Narbutt, Graham I. Harrison, Karl P. Lawrence, Kristi De Grys, K.a. Baczynska, Kylie A. Morgan, Irmina Olejniczak-staruch, Peter A. Philipsen, Michał Rogowski-tylman, Angela TewariAbstract:BACKGROUND: Sun protection factor (SPF) is assessed with sunscreen applied at 2 mg cm-2 . People typically apply around 0·8 mg cm-2 and use sunscreen daily for holidays. Such use results in Erythema, which is a risk factor for skin cancer. OBJECTIVES: To determine (i) whether typical sunscreen use resulted in Erythema, epidermal DNA damage and photoimmunosuppression during a sunny holiday, (ii) whether optimal sunscreen use inhibited Erythema and (iii) whether Erythema is a biomarker for photoimmunosuppression in a laboratory study. METHODS: Holidaymakers (n = 22) spent a week in Tenerife (very high ultraviolet index) using their own sunscreens without instruction (typical sunscreen use). Others (n = 40) were given SPF 15 sunscreens with instructions on how to achieve the labelled SPF (sunscreen intervention). Personal ultraviolet radiation (UVR) exposure was monitored electronically as the standard Erythemal dose (SED) and Erythema was quantified. Epidermal cyclobutane pyrimidine dimers (CPDs) were determined by immunostaining, and immunosuppression was assessed by contact hypersensitivity (CHS) response. RESULTS: There was no difference between personal UVR exposure in the typical sunscreen use and sunscreen intervention groups (P = 0·08). The former had daily Erythema on five UVR-exposed body sites, increased CPDs (P < 0·001) and complete CHS suppression (20 of 22). In comparison, Erythema was virtually absent (P < 0·001) when sunscreens were used at ≥ 2 mg cm-2 . A laboratory study showed that 3 SED from three very different spectra suppressed CHS by around ~50%. CONCLUSIONS: Optimal sunscreen use prevents Erythema during a sunny holiday. Erythema predicts suppression of CHS (implying a shared action spectrum). Given that Erythema and CPDs share action spectra, the data strongly suggest that optimal sunscreen use will also reduce CPD formation and UVR-induced immunosuppression.
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perspectives of uv nowcasting to monitor personal pro health outdoor activities
Journal of Photochemistry and Photobiology B-biology, 2018Co-Authors: Janusz W Krzyścin, Joanna Narbutt, Aleksandra Lesiak, Piotr Sobolewski, Jakub GuzikowskiAbstract:Abstract Nowcasting model for online monitoring of personal outdoor behaviour is proposed. It is envisaged that it will provide an effective e-tool used by smartphone users. The model could estimate maximum duration of safe (without Erythema risk) outdoor activity. Moreover, there are options to estimate duration of sunbathing to get adequate amount of vitamin D3 and doses necessary for the antipsoriatic heliotherapy. The application requires information of starting time of sunbathing and the user's phototype. At the beginning the user will be informed of the approximate duration of sunbathing required to get the minimum Erythemal dose, adequate amount of vitamin D3, and the dose necessary for the antipsoriatic heliotherapy. After every 20-min the application will recalculate the remaining duration of sunbathing based on the UVI measured in the preceding 20 min. If the estimate of remaining duration is
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increased cyclooxygenase expression and thymine dimer formation after repeated exposures of humans to low doses of solar simulated radiation
Experimental Dermatology, 2007Co-Authors: Joanna Narbutt, Cezary Jochymski, Wojciech Kozlowski, Anna Sysajedrzejowska, Aleksandra Lesiak, Mary NorvalAbstract:: The impact of repeated doses of solar simulated radiation (SSR) has not been evaluated, particularly to determine if photoadaptation and photoprotection develop over time. In this study, Erythema, pigmentation, cyclooxygenase (COX)-1 and 2 expression and thymine dimer (dTT) formation were evaluated in the skin of irradiated subjects of phototype II or III. Groups of 7-10 volunteers were whole-body irradiated with a low dose of SSR on each of 10 consecutive days followed by a single Erythemal ultraviolet B (UVB) dose on a small body area, or irradiated only with the single Erythemal UVB dose on a small body area, or irradiated with the low dose of SSR on each of 30 consecutive days, or were unirradiated. Erythema and pigmentation were measured 24 h after the final SSR or UVB, and skin biopsies collected for the assessment of COX(+) cells and dTT(+) nuclei. The repeated SSR exposures induced a small increase in pigmentation without Erythema, and were slightly protective against the Erythemal effects of the subsequent high UVB dose. The number of COX-1(+) and 2(+) cells increased as a result of 10-days SSR and rose still further after 30-days SSR, indicating that photoadaptation had not developed. The SSR exposures did not result in any protection against the further increase in COX-1 and 2 expression caused by the Erythemal UVB dose. In contrast, for dTT formation, the repeated SSR exposures led to a limited degree of both photoadaptation and photoprotection.
Angela Tewari - One of the best experts on this subject based on the ideXlab platform.
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sunscreen applied at 2 mg cm 2 during a sunny holiday prevents Erythema a biomarker of ultraviolet radiation induced dna damage and suppression of acquired immunity
British Journal of Dermatology, 2019Co-Authors: Joanna Narbutt, Graham I. Harrison, Karl P. Lawrence, Kristi De Grys, K.a. Baczynska, Kylie A. Morgan, Michal Rogowskitylman, Irmina Olejniczakstaruch, Peter A. Philipsen, Angela TewariAbstract:BACKGROUND: Sun protection factor (SPF) is assessed with sunscreen applied at 2 mg cm-2 . People typically apply around 0·8 mg cm-2 and use sunscreen daily for holidays. Such use results in Erythema, which is a risk factor for skin cancer. OBJECTIVES: To determine (i) whether typical sunscreen use resulted in Erythema, epidermal DNA damage and photoimmunosuppression during a sunny holiday, (ii) whether optimal sunscreen use inhibited Erythema and (iii) whether Erythema is a biomarker for photoimmunosuppression in a laboratory study. METHODS: Holidaymakers (n = 22) spent a week in Tenerife (very high ultraviolet index) using their own sunscreens without instruction (typical sunscreen use). Others (n = 40) were given SPF 15 sunscreens with instructions on how to achieve the labelled SPF (sunscreen intervention). Personal ultraviolet radiation (UVR) exposure was monitored electronically as the standard Erythemal dose (SED) and Erythema was quantified. Epidermal cyclobutane pyrimidine dimers (CPDs) were determined by immunostaining, and immunosuppression was assessed by contact hypersensitivity (CHS) response. RESULTS: There was no difference between personal UVR exposure in the typical sunscreen use and sunscreen intervention groups (P = 0·08). The former had daily Erythema on five UVR-exposed body sites, increased CPDs (P < 0·001) and complete CHS suppression (20 of 22). In comparison, Erythema was virtually absent (P < 0·001) when sunscreens were used at ≥ 2 mg cm-2 . A laboratory study showed that 3 SED from three very different spectra suppressed CHS by around ~50%. CONCLUSIONS: Optimal sunscreen use prevents Erythema during a sunny holiday. Erythema predicts suppression of CHS (implying a shared action spectrum). Given that Erythema and CPDs share action spectra, the data strongly suggest that optimal sunscreen use will also reduce CPD formation and UVR-induced immunosuppression.
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Sunscreen applied at ≥ 2 mg cm-2 during a sunny holiday prevents Erythema, a biomarker of ultraviolet radiation-induced DNA damage and suppression of acquired immunity.
British Journal of Dermatology, 2018Co-Authors: Joanna Narbutt, Graham I. Harrison, Karl P. Lawrence, Kristi De Grys, K.a. Baczynska, Kylie A. Morgan, Irmina Olejniczak-staruch, Peter A. Philipsen, Michał Rogowski-tylman, Angela TewariAbstract:BACKGROUND: Sun protection factor (SPF) is assessed with sunscreen applied at 2 mg cm-2 . People typically apply around 0·8 mg cm-2 and use sunscreen daily for holidays. Such use results in Erythema, which is a risk factor for skin cancer. OBJECTIVES: To determine (i) whether typical sunscreen use resulted in Erythema, epidermal DNA damage and photoimmunosuppression during a sunny holiday, (ii) whether optimal sunscreen use inhibited Erythema and (iii) whether Erythema is a biomarker for photoimmunosuppression in a laboratory study. METHODS: Holidaymakers (n = 22) spent a week in Tenerife (very high ultraviolet index) using their own sunscreens without instruction (typical sunscreen use). Others (n = 40) were given SPF 15 sunscreens with instructions on how to achieve the labelled SPF (sunscreen intervention). Personal ultraviolet radiation (UVR) exposure was monitored electronically as the standard Erythemal dose (SED) and Erythema was quantified. Epidermal cyclobutane pyrimidine dimers (CPDs) were determined by immunostaining, and immunosuppression was assessed by contact hypersensitivity (CHS) response. RESULTS: There was no difference between personal UVR exposure in the typical sunscreen use and sunscreen intervention groups (P = 0·08). The former had daily Erythema on five UVR-exposed body sites, increased CPDs (P < 0·001) and complete CHS suppression (20 of 22). In comparison, Erythema was virtually absent (P < 0·001) when sunscreens were used at ≥ 2 mg cm-2 . A laboratory study showed that 3 SED from three very different spectra suppressed CHS by around ~50%. CONCLUSIONS: Optimal sunscreen use prevents Erythema during a sunny holiday. Erythema predicts suppression of CHS (implying a shared action spectrum). Given that Erythema and CPDs share action spectra, the data strongly suggest that optimal sunscreen use will also reduce CPD formation and UVR-induced immunosuppression.
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uva1 induces cyclobutane pyrimidine dimers but not 6 4 photoproducts in human skin in vivo
Journal of Investigative Dermatology, 2012Co-Authors: Angela Tewari, Robert Sarkany, Antony R YoungAbstract:UVB readily induces cyclobutane pyrimidine dimers, mainly thymine dimers (TTs), and pyrimidine (6-4) pyrimidone photoproducts (6-4PPs) in DNA. These lesions result in "UVB signature mutations" found in skin cancers. We have investigated the induction of TTs and 6-4PPs in human skin in vivo by broadband UVA1, and have compared this with comparable Erythemal doses of monochromatic UVB (300nm). In vitro and ex vivo studies have shown the production of TTs, without 6-4PPs, by UVA1. We show that UVA1 induces TTs, without 6-4PPs, in the epidermis of healthy volunteers in vivo , whereas UVB induced both photoproducts. UVB induced more TTs than UVA1 for the same level of Erythema. The level of UVA1-induced TTs increased with epidermal depth in contrast to a decrease that was seen with UVB. UVA1- and UVB-induced TTs were repaired in epidermal cells at a similar rate. The mechanism by which UVA1 induces TTs is unknown, but a lack of intra-individual correlation between our subjects' UVB and UVA1 minimal Erythema doses implies that UVA1 and UVB Erythema occur by different mechanisms. Our data suggest that UVA1 may be more carcinogenic than has previously been thought.
Lesley E. Rhodes - One of the best experts on this subject based on the ideXlab platform.
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tomato paste rich in lycopene protects against cutaneous photodamage in humans in vivo a randomized controlled trial
British Journal of Dermatology, 2011Co-Authors: Mohammad Rizwan, Andrew Harbottle, I Rodriguezblanco, Mark A Birchmachin, Rachel E B Watson, Lesley E. RhodesAbstract:Summary Background Previous epidemiological, animal and human data report that lycopene has a protective effect against ultraviolet radiation (UVR)-induced Erythema. Objectives We examined whether tomato paste – rich in lycopene, a powerful antioxidant – can protect human skin against UVR-induced effects partially mediated by oxidative stress, i.e. Erythema, matrix changes and mitochondrial DNA (mtDNA) damage. Methods In a randomized controlled study, 20 healthy women (median age 33 years, range 21–47; phototype I/II) ingested 55 g tomato paste (16 mg lycopene) in olive oil, or olive oil alone, daily for 12 weeks. Pre- and postsupplementation, UVR Erythemal sensitivity was assessed visually as the minimal Erythema dose (MED) and quantified with a reflectance instrument. Biopsies were taken from unexposed and UVR-exposed (3 × MED 24 h earlier) buttock skin pre- and postsupplementation, and analysed immunohistochemically for procollagen (pC) I, fibrillin-1 and matrix metalloproteinase (MMP)-1, and by quantitative polymerase chain reaction for mtDNA 3895-bp deletion. Results Mean ± SD Erythemal D30 was significantly higher following tomato paste vs. control (baseline, 26·5 ± 7·5 mJ cm−2; control, 23 ± 6·6 mJ cm−2; tomato paste, 36·6 ± 14·7 mJ cm−2; P = 0·03), while the MED was not significantly different between groups (baseline, 35·1 ± 9·9 mJ cm−2; control, 32·6 ± 9·6 mJ cm−2; tomato paste, 42·2 ± 11·3 mJ cm−2). Presupplementation, UVR induced an increase in MMP-1 (P = 0·01) and a reduction in fibrillin-1 (P = 0·03). Postsupplementation, UVR-induced MMP-1 was reduced in the tomato paste vs. control group (P = 0·04), while the UVR-induced reduction in fibrillin-1 was similarly abrogated in both groups, and an increase in pCI deposition was seen following tomato paste (P = 0·05). mtDNA 3895-bp deletion following 3 × MED UVR was significantly reduced postsupplementation with tomato paste (P = 0·01). Conclusions Tomato paste containing lycopene provides protection against acute and potentially longer-term aspects of photodamage.
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Tomato paste rich in lycopene protects against cutaneous photodamage in humans in vivo.
British Journal of Dermatology, 2010Co-Authors: Mohammad Rizwan, Isabel Rodríguez-blanco, Andrew Harbottle, Mark A. Birch-machin, Watson Reb., Lesley E. RhodesAbstract:Summary Background Previous epidemiological, animal and human data report that lycopene has a protective effect against ultraviolet radiation (UVR)-induced Erythema. Objectives We examined whether tomato paste – rich in lycopene, a powerful antioxidant – can protect human skin against UVR-induced effects partially mediated by oxidative stress, i.e. Erythema, matrix changes and mitochondrial DNA (mtDNA) damage. Methods In a randomized controlled study, 20 healthy women (median age 33 years, range 21–47; phototype I/II) ingested 55 g tomato paste (16 mg lycopene) in olive oil, or olive oil alone, daily for 12 weeks. Pre- and postsupplementation, UVR Erythemal sensitivity was assessed visually as the minimal Erythema dose (MED) and quantified with a reflectance instrument. Biopsies were taken from unexposed and UVR-exposed (3 × MED 24 h earlier) buttock skin pre- and postsupplementation, and analysed immunohistochemically for procollagen (pC) I, fibrillin-1 and matrix metalloproteinase (MMP)-1, and by quantitative polymerase chain reaction for mtDNA 3895-bp deletion. Results Mean ± SD Erythemal D30 was significantly higher following tomato paste vs. control (baseline, 26·5 ± 7·5 mJ cm−2; control, 23 ± 6·6 mJ cm−2; tomato paste, 36·6 ± 14·7 mJ cm−2; P = 0·03), while the MED was not significantly different between groups (baseline, 35·1 ± 9·9 mJ cm−2; control, 32·6 ± 9·6 mJ cm−2; tomato paste, 42·2 ± 11·3 mJ cm−2). Presupplementation, UVR induced an increase in MMP-1 (P = 0·01) and a reduction in fibrillin-1 (P = 0·03). Postsupplementation, UVR-induced MMP-1 was reduced in the tomato paste vs. control group (P = 0·04), while the UVR-induced reduction in fibrillin-1 was similarly abrogated in both groups, and an increase in pCI deposition was seen following tomato paste (P = 0·05). mtDNA 3895-bp deletion following 3 × MED UVR was significantly reduced postsupplementation with tomato paste (P = 0·01). Conclusions Tomato paste containing lycopene provides protection against acute and potentially longer-term aspects of photodamage.
Jonatha Rees - One of the best experts on this subject based on the ideXlab platform.
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the physiological and phenotypic determinants of human tanning measured as change in skin colour following a single dose of ultraviolet b radiation
Experimental Dermatology, 2010Co-Authors: Terence H Wong, Ia J Jackso, Jonatha ReesAbstract:Please cite this paper as: The physiological and phenotypic determinants of human tanning measured as change in skin colour following a single dose of ultraviolet B radiation. Experimental Dermatology 2010; 19: 667–673. Abstract: Experimental study of the in vivo kinetics of tanning in human skin has been limited by the difficulties in measuring changes in melanin pigmentation independent of the ultraviolet-induced changes in Erythema. The present study attempted to experimentally circumvent this issue. We have studied Erythemal and tanning responses following a single exposure to a range of doses of ultraviolet B irradiation on the buttock and the lower back in 98 subjects. Erythema was assessed using reflectance techniques at 24 h and tanning measured as the L* spectrophotometric score at 7 days following noradrenaline iontophoresis. We show that dose (P < 0.0001), body site (P < 0.0001), skin colour (P < 0.0001), ancestry (P = 0.0074), phototype (P = 0.0019) and sex (P = 0.04) are all independent predictors of Erythema. Quantitative estimates of the effects of these variables are reported, but the effects of ancestry and phototype do not appear solely explainable in terms of L* score. Dose (P < 0.0001), body site (P < 0.0001) and skin colour (P = 0.0365) or, as an alternative to skin colour, skin type (P = 0.0193) predict tanning, with those with lighter skin tanning slightly more to a defined UVB dose. If Erythema is factored into the regression, then only dose and body site remain significant predictors of tanning: therefore neither phototype nor pigmentary factors, such as baseline skin colour, or eye or hair colour, predict change in skin colour to a unit Erythemal response.
Alfredo Colosimo - One of the best experts on this subject based on the ideXlab platform.
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investigation on the capability of polysulphone for measuring biologically effective solar uv exposures
Photochemical and Photobiological Sciences, 2014Co-Authors: Anna Maria Siani, Giuseppe Rocco Casale, Sarah Modesti, Alfio V Parisi, Alfredo ColosimoAbstract:Polysulphone (PS) dosimetry is a well-known technique broadly used to assess the Erythemally effective solar UV dose received by anatomical sites (personal exposure). We investigate the capability of PS dosimetry to convert doses absorbed by PS badges into biologically effective solar UV exposures taking as examples two relevant effects for human skin: Erythema induction and pre-vitamin D3 production. PS calibration curves for Erythemal and pre-vitamin D3 were distinctly determined by using an empirical relationship between the biologically effective UV exposures and the PS absorbance change. This relationship is parameterized by a coefficient, distinct for each of the two considered biological effects, multiplying the same cubic polynomial function. It is shown how the multiplying coefficient is related to the ratio between the biologically effective and the PS weighted irradiances which is the prevailing factor affecting the accuracy of the calibration and, consequently, the capability of PS films for measuring biologically effective solar UV exposures. The points addressed in this paper can be extended to other biological effects of interest whose action spectra have some similarity with the PS film response.
