ArticleLiterature Review

Skin cancer: Role of ultraviolet radiation in carcinogenesis

Authors:
To read the full-text of this research, you can request a copy directly from the authors.

Abstract

Abstract UV radiation is a carcinogen known to play a role in the development of non-melanoma and melanoma skin cancers. Acute and chronic exposure to UV radiation causes clinical and biological effects that promote the unregulated proliferation of skin cells. In recent decades, changes in climate and increased air pollution have led to environmental changes that increase UV light transmission. In this chapter, we discuss sources of UV radiation that are relevant to human health, as well as the acute and chronic effects that result from UV radiation exposure.

No full-text available

Request Full-text Paper PDF

To read the full-text of this research,
you can request a copy directly from the authors.

... INTRODUCTION Ultraviolet (UV) radiation is the most prevalent carcinogen in our environment, and can be divided into three categories: UVA, UVB, and UVC (reviewed in (1)). Of these, UVB is commonly thought to cause the most damage to the skin, although UVA and UVC can be harmful as well. ...
... While UVB light is required to stimulate the skin to produce vitamin D that is essential for calcium homeostasis and metabolism (2,3), excessive UVB can lead to oxidative stress within the skin via disproportionate generation of reactive oxygen species (ROS), if not balanced by antioxidant defenses to maintain redox homeostasis (4). UVB radiation also directly causes DNA damage by formation of cyclobutane pyrimidine dimers (CPDs) and pyrimidine (6-4)-pyrimidone photoproduct lesions, which have been shown to be carcinogenic (1,5). ...
... Collectively, oxidative stress, DNA damage, and inflammation, as well as mutation(s) in regulatory genes by UV radiation have been linked to cellular dysfunction and the development of greater than 90% of skin cancer cases (1). As the most common neoplasm in the United States, non-melanoma skin cancers (NMSC) are morbid, but can often be treated by surgery, chemotherapy, photodynamic therapy, and/or radiation therapy unless left untreated for too long or present in hard-to-treat areas (6). ...
Article
We recently showed that dietary grape powder (GP) imparts considerable protection against ultraviolet B (UVB)-mediated skin carcinogenesis in SKH-1 mice. To determine molecular mechanisms of this response, we employed tandem mass tag (TMT) quantitative global proteomics approach on skin tumors from mice exposed to 180 mJ/cm2 UVB twice per week and fed control or 5% GP diet. We found 2,629 proteins modulated by GP feeding, with 34 identified using stringent cutoffs (false discovery rate (FDR) q-value ≤0.1, fold change ≥1.2, p-value ≤0.05, ≥3 unique peptides). Ingenuity Pathway Analysis helped identify seven proteins involved in protein ubiquitination, including the deubiquitinase UCHL5 and 6 subunits of the 20S proteasome (PSMA1,3,4,6 and PSMB4,7). A second data set without the FDR q-value identified 239 modulated proteins, seven of which are involved in protein ubiquitination. Further, 14 proteins involved in acute phase response signaling were modulated >1.5-fold, including acute phase proteins APCS, FGA, FGB, HP, HPX, and RBP1. Evaluation of upstream regulators found inhibition of ERK1/2 phosphorylation and NF-κB p65, and an increase in IκBα in GP-treated tumors. Overall, our data suggested that GP consumption may mitigate tumorigenesis by enhancing protein ubiquitination and degradation caused by oxidative stress, and manipulates an otherwise tumor-promoting anti-inflammatory environment.
... In the area of environmental and dermatological photo-biology, UV radiation is usually classified in UV-A (from 400 to 320 nm), UV-B (from 320 to 290 nm) and UV-C (from 290 to 200 nm) [ Fig. 2]. Fortunately, the UV-C, being the most energetic form of UV, does not reach the ground level because it is absorbed by the ozone layer [31,34,37]. ...
... However, it only minimally filters UV-A radiation, ending in more than 95% reaching the surface of the Earth. In theory, around 5% of UV-B and 95% of UV-A of UV radiation, impinges upon the skin's surface [31,37]. ...
... Incomplete repair of the DNA and removal of these mutagenic photo-products result in uncontrolled proliferation of the cells, leading to the development of skin cancer [31,37,44]. ...
... Traditionally, nonmelanoma skin cancers (NMSCs) are considered mainly UV-related malignancies with an increased incidence in the elderly, where frequently there is evidence of damage from chronic sun exposure. 1 Chronic trauma, 2 scars, 3 chronic wounds, 4 X-ray 5 and arsenic exposure, 6 and immunodeficiency 7 are also associated with the onset of NMSCs. ...
... The carcinogenic role of UV radiation has long been demonstrated within the NMSCs. 1 Acute and chronic exposure to UV radiation promotes a deregulated proliferation of skin cells through genomic changes in all of the 3 stages of photo-carcinogenesis initiation, promotion, and progression. 18 Besides the direct molecular damage, the carcinogenic effects of UV radiation are also related to immune system impairment yielding to survival and proliferation of abnormal cells and oncogenic viruses. ...
Article
Full-text available
Background: Traditionally, nonmelanoma skin cancers (NMSCs) are considered mainly UV-related malignancies. Nevertheless, a strong correlation between the embryologically relevant sites (ERS) of the head and neck and the preferential sites of onset of basal cell carcinomas (BCCs) has long been supposed and demonstrated. The aim of this research was the investigation of the potential correlation between the ERS of the head and neck and the sites of tumor onset in all of the NMSCs. Methods: The distribution of 1165 NMSC was correlated with the ERS of the head and neck using the universally accepted anatomical diagrams featuring the congenital head and neck clefts and an original anatomical diagram showing the most credited sites of the embryonic fusion planes of the auricle. Results: In our sample, both BCC and SSC display an increased likelihood of onset in the ERS of the head and neck. A proportion of 93.10% BCCs was distributed within ERS, while 6.90% derived from non-embryologically relevant sites (P < 0.001). A proportion of 69.70% SCCs was distributed within ERS, while 30.30% derived from non-embryologically relevant sites (P < 0.001). The probability of tumors within ERS was significantly higher for BCC versus SCC (P < 0.001), with BCCs having a 5-fold increase in the probability of occurring in ERS compared to SCCs (P < 0.001). Conclusions: The ERS might host areas of cellular instability yielding to the development of an NMSC. The environmental UV exposure plays a relatively main role versus dysontogenic factors in the pathogenesis of SCC.
... For decades, ultraviolet radiation receives rapidly growing attention due to its indispensable role in industrial production, security and anti-counterfeiting, health care, and other related fields [1][2][3][4] . However, excessive ultraviolet radiation would cause irreversible damage to human, such as epidermal hyperplasia, DNA damage, and melanoma skin cancers [5][6] . Since UV light is invisible to the naked eyes, the development of UV light detection materials is essential for the purpose of protection and radiation control. ...
... In the free space, there are tetraethylammonium cations to compensate the negative charge of the uranyl layers. The formula of UPhPC-1 is determined to be (TEA) 2 (UO 2 ) 5 (PhPC) 6 taken the results of single crystal structural analysis and elemental analysis (Table S2) into consideration. The FT-IR spectrum of UPhPC-1 was collected without KBr at room temperature. ...
... NMSCs are mostly composed of basal cell carcinomas and squamous cell carcinomas, which arise in the epidermis from keratinocytes that have undergone malignant transformation (Bowden, 2004). Solar UVR is believed to be the most prevalent natural carcinogen in our environment and has been identified as a causative factor for approximately 90% of NMSC cases (Mancebo and Wang, 2014). Solar UVR that penetrates the atmosphere is mainly composed of UVA (90%e99%, 320e400 nm) and UVB (1%e10%, 290e320 nm) radiation, whereas most of the higher energy UVR (UVC, is absorbed by stratospheric ozone and other atmospheric components (Chhabra et al., 2017). ...
... However, CPDs are poorly recognized, and repair can be ineffective. These dimers result in the transcription of C>T or CC>TT UVB signature mutations (de Gruijl, 1999;Ichihashi et al., 2003;Mancebo and Wang, 2014) found in multiple tumor-related genes, including tumor suppressor p53 Q3 , a gene mutated in approximately 90% of human squamous cell carcinomas (Agar et al., 2004) and up to 100% in SKH-1 mouse carcinomas Q4 (Melnikova et al., 2005). Moreover, it has been shown that CPDs may cause NMSC tumorigenesis (Jans et al., 2005). ...
Article
Skin cancer is the most frequently diagnosed cancer in the United States, and solar UVR is an established causative factor for approximately 90% of these cases. Despite efforts aimed at UV protection, including use of sunscreen and clothing, annual cases of skin cancer continue to rise. Here, we report that dietary grape powder mitigates UVB-mediated skin carcinogenesis in an SKH-1 hairless mouse model. Using a UVB initiation-promotion protocol, whereby mice were exposed to 180 mJ/cm² UVB two times per week for 28 weeks, we determined the effects of a grape powder-fortified diet (3% or 5%) on skin carcinogenesis. Grape powder consumption at both doses resulted in marked inhibition in tumor incidence, as well as a delay in onset of tumorigenesis. Molecular analyses of skin and tumor tissue showed that grape powder-mediated protective response against UVB-induced skin cancer was accompanied by enhanced DNA damage repair, reduced proliferation, increased apoptosis, and modulations in several oxidative stress markers specifically related to inhibition of oxidative stress and increased reactive oxygen species metabolism. NRF2, an activator of cellular antioxidant response, was decreased by grape powder feeding, suggesting a supportive role in tumor cell survival. Overall, our study suggested that dietary grape, containing several antioxidants in natural amalgamation, may protect against UVB-mediated skin carcinogenesis.
... It is mostly absorbed by the ozone layer in the atmosphere (Dupont, Gomez et al. 2013). UV-B light (280 to 320 nm) is only partially absorbed by the ozone layer, making it the biologically active radiation in the induction of direct DNA damage (Mancebo and Wang 2014). Although humans need UV-B for the production of the essential vitamin D, it is the main cause for the development of skin cancer (Yagura, Makita et al. 2011). ...
... The UV light has been used for medical treatment [14], astronomy [15], and other applications [13,16]. Exposure to UV radiation can cause various diseases, such as skin cancer [17]. Consequently, detecting UV light at different wavelengths and intensities has become a crucial task. ...
Article
Full-text available
We studied the performance of a photodiode UV sensor based on a p-NiO/n-Si heterojunction. NiO thin film was prepared via a two-step process. In the first step, a thin film of Ni metal was evaporated on an n-Si substrate. Subsequently, the sample was thermally oxidized at 500 °C for 3 h in an ambient atmosphere. The phases and surface morphology of the prepared sample was determined by using x-ray diffraction analysis and scanning electron microscopy, respectively. The rectifying ratio of the prepared device was approximately 7 at a bias voltage of ±10 V, with a barrier height and ideality factor of 0.77 ± 0.03 eV and 16, respectively. The prepared device was tested for potential applications as a UV sensor. The prepared device exhibits high repeatability and fast response times of 1.5 s and 0.7 s for the rise and full time, respectively. The prepared photodiode responds to low-intensity UV light in the range from 30 μW·cm−2 to 430 μW·cm−2.
... Nonmelanoma skin cancers (NMSC) are common and their incidence is rising. 10,11 It has been well documented that ultraviolet radiation exposure is a risk factor for the development of NMSC, 12,13 but other factors may also influence the risk of development of these cancers. Although an inverse correlation between obesity and the risk of NMSC has been reported, [14][15][16] the interaction between measures of obesity (such as BMI and waist-to-hip ratio, WHR) and sun exposure has not been studied. ...
Article
The Clinical Update series is intended to help busy providers stay up to date with important and potentially practice changing articles that have been published on topics pertinent to the care of women. The rates of obesity and the resultant morbidities are rising worldwide, making it a high-priority health issue for the medical community. Moreover, the pathophysiology and management of obesity and visceral fat accumulation in women has important nuances, distinct from those in men. It is important to consider the effect of unique female-specific influences such as reproductive stage and pregnancy. Therefore, we have chosen to review six high-impact recent studies relating to obesity and its management in women. These include guidelines for management of obesity in pregnancy, risk of nonmelanoma skin cancer in overweight/obese women, the association of vascular fat and decline in physical function in midlife women, the predictors for weight gain in premenopausal women with early-stage breast cancer, dietary patterns and obesity in postmenopausal women, and finally, normal weight obesity and mortality risk in postmenopausal women.
... Cutaneous squamous cell carcinomas (SCCs) and basal cell carcinomas (BCCs) are the most common skin cancers in the United States. Approximately, 5.4 million SCCs and BCCs are diagnosed annually and their incidence is rising [1] Both SCCs and BCCs are keratinocyte carcinomas (KCs) and exposure to ultraviolet (UV) radiation is the most important environmental factor involved in their initiation [2]. Despite the similarities in their origin and cause, SCCs and BCCs have distinct clinical features: SCCs are more aggressive and more likely to metastasize at late stages, while BCCs are more indolent and rarely metastasize [3]. ...
Article
Full-text available
Cutaneous squamous cell carcinomas (SCCs) and basal cell carcinomas (BCCs) have different clinical behaviors, despite both being keratinocyte carcinomas mainly caused by ultraviolet radiation. Whether these distinct features are associated with tumor-associated macrophages (TAMs) is largely unknown. The main goal of this study was to conduct a comprehensive analysis of density and polarization states of TAMs in SCCs versus BCCs. The role of lactic acid in TAM polarization in SCC versus BCC was examined. We found that SCCs have a higher density of CD68 + TAMs compared to BCCs. TAMs in SCCs express higher levels of TAM-associated markers (arginase-1, MMP9, CD40 and CD127) than those in BCCs. Interestingly, differential expression of TAM-associated markers between SCCs and BCCs was reproduced in human monocytic THP-1 cells stimulated with SCC- or BCC-conditioned media. Analysis of soluble factor(s) in these tumors further revealed that SCCs have a significantly higher concentration of lactic acid than BCCs, and lactic acid was sufficient to upregulate TAM markers. Our results demonstrate that TAMs in SCCs versus BCCs differ in density and polarization states, which can be determined by soluble factors including tumor-derived lactic acid. These differences in TAMs may contribute to the distinct clinical behaviors of SCCs versus BCCs. This work was supported by grants from the National Institutes of Health and the Doris Duke Charitable Foundation. Research in context: Few studies have studied tumor-associated macrophages in the context of SCC versus BCC. It has been demonstrated that macrophages mobilize to the epidermis after being exposed to ultraviolet-B radiation and produce interleukin-10 (IL-10). It has also been shown that the production of IL-10 results in the evasion of T cell-mediated immunity in BCCs and SCCs. However, the relationship between TAMs and the clinical behaviors of SCCs and BCCs remains largely unclear. Our study shows that despite their similar origins, human cutaneous SCCs and BCCs are considerably different in their TAMs. To our knowledge, these results provide the first evidence of differential TAM density and polarization in SCCs versus BCCs, which may contribute to their characteristic clinical behaviors. Future studies are necessary to elucidate the mechanisms by which TAMs influence these cancers with the goal of developing therapies tailored to each type of malignancy.
... Additionally, UV radiation is a carcinogen known to play a role in the development of non-melanoma and melanoma skin cancers. 27 Chemotherapy is adopted more for metastatic cancer with detectable primary sites originating from the skin, breast and ovary but less for those originating from the lung. This may be because chemotherapy is an effective systemic therapy for those cancers [28][29][30] but it is less often selected as a treatment for lung cancer because it is hard to identify primary and metastatic lung lesions. ...
Article
Full-text available
Background: This study investigates the characteristics of a special type of cancer of unknown primary site (CUP, type 2), which is a metastasis of a definite pathological diagnosis without a detectable primary site. Patients and methods: Patients diagnosed between 2004 and 2014 were identified from the Surveillance Epidemiology and End Results (SEER) database. The characteristics of type 2 CUP from different sources were analyzed. For each source of type 2 CUP, tumors of the corresponding Tn N0-X M1 stage were used as controls. Results: A total of 8505 patients with type 2 CUP were included in this analysis. Type 2 CUP shows an increasing trend, while type 1 shows the opposite. Type 2 CUPs have significant differences with stage IV of the same pathological primary lesion. Many characteristics influenced the prognosis of type 2 CUP patients, including marital status, age, race, sex, registration time, lymph node metastasis, surgery, chemotherapy, and radiation. Conclusion: Our study suggests that identifying the source of metastasis is the key to the selection of treatment and the determination of the prognosis for CUP.
... According to oxford dictionary (2018), the word access is defined as the means or opportunity to approach or enter a place. The access to sunscreen is the ability or opportunity to use or benefit from sunscreens (Mancebo & Wang, 2014). ...
... Ultraviolet light (UV) is a type of radiation that is part of sunlight, and exposure to UV varies depending on factors such as air pollution, ozone layer thickness, and weather conditions. Exposure can induce adverse effects, such as erythema or skin tightness, leading to photoaging and, if the exposure is prolonged or accumulative, more serious conditions such as skin cancer [138]. The relationships between UV exposure and epigenetic marks are varied. ...
Chapter
Epigenetic modifications play an essential role in the functional regulation of genes, including their expression. In contrast to the relative stability of the genome, the epigenome varies in a very dynamic way, through what are known as epigenetic mechanisms. These epigenetic modifications are reversible and are conditioned by environmental pressures. The most well-known epigenetic DNA modifications are the methylation of the cytosines present in the context of cytosine-guanine dinucleotides and the posttranslational modification of histones. Several works have reported that events in the early environment are associated with changes in gene expression and biological function and that such changes persist beyond the immediate influence of the stimulus and into adulthood. While the exact molecular mechanisms underlying developmental programming are largely unknown, there is much epidemiological evidence and data from animal studies linking epigenetic modifications with parental lifestyle (e.g., alcohol or tobacco consumption), nutrition, and environmental factors (such as exposure to UV light or heavy metals and stress). Moreover, pre-existing pathologies in the parents (e.g., diabetes, obesity, or metabolic syndrome) can also increase the susceptibility of the offspring to developing certain diseases over the course of their lifetime.
... A melanized stratum corneum would confer photoprotection to the lower epidermal layers, thus avoiding lesions associated with UV exposure, including basal cell carcinoma, squamous cell carcinoma and melanoma. 35 In contrast to the increasing incidence of skin cancer and actinic damage in humans, 23,28 and some other aquatic and terrestrial animals, 5,6,8,9,[36][37][38] no form of UV-induced skin cancer has been reported to date in mysticete and odontocete cetaceans. Evidence of photodamage to the mitochondrial DNA has been detected in the skin of three species of whales 10,30 in the absence of any evidence of oncogenic transformation. ...
Presentation
The skin is one of the most complex and multifunctional organs. In mammals, one of its main functions is to absorb ultraviolet radiation (UVr), considered to be of the most damaging exogenous factors that exist. UVr absorption is performed by melanin, a photocompound produced by melanocytes, located in epidermis basal layer and that is transmitted to basal and keratinocytes of the stratum spinosum, where it covers the cell nucleus as a mechanism of photoprotection. We recently demonstrated that UVr can produce damage to cetacean skin, however, knowledge about their basic histology is very limited. Here, we analyzed 25 skin smear slides stained with Papanicolau, as well as 10 histological skin sections of live individuals of five cetacean species (Tursiops truncatus, Balaenoptera edeni, Stenella atenuata, S. longirostris and Megaptera novaeangliae) that were sampled in the Mexican Central Pacific. Histological slides showed that melanin was distributed all across the cellular column, even at the keratinized layer, which implies a photoprotective strategy different than that described for terrestrial mammals. The area of the basal (F=42.52, p=1.96e-05) and stratum spinosum cells (F=22.72, p=2e-04) varied between species, being greater for mysticetes than odontocetes. That implies a greater barrier for UVr to reach the basal layer in mysticetes, so we would expect greater attenuation and less damage of the basal cells and dermis. We also detected differences between the numbers of melanophages between species (KW chi-2=16.307, p=0.0026), humpback whales having the highest percentage (69.66%) of these immune cells. Our results could reflect initial acclimatization of this species under pressure of high levels of UVr in the Mexican Central Pacific. Our work is a first step towards understanding the importance of ultraviolet radiation in the evolutionary history of cetacean skin.
... These changes result from direct DNA damage, primarily from UVB, as well as from free radical damage caused by inflammation and UVA. 2,3 ...
Article
Full-text available
Background Premature skin aging results from exposure to a range of environmental factors, primarily ultraviolet radiation, but also high‐energy visible light in the blue spectrum, infrared radiation, and environmental pollution. These extrinsic factors result in the generation of reactive oxygen species which promote photoaging and DNA damage resulting in skin cancers. Aims To formulate skincare products utilizing a new coating applied to zinc oxide and titanium dioxide particles and complimentary skincare ingredients to provide broad protection against a range of environmental insults. Methods A cross‐polymer, multifunctional coating of silicate, polyalkylsilsesquioxane, and polydimethylsiloxane moieties increases the photostability and decreases the reactivity of mineral sunscreen agents when interacting with energy sources. These products are also formulated with antioxidants to minimize free radical propagation. Additionally, this coating improves the esthetic feel of mineral sunscreens, while the appearance is enhanced by formulating products with a blend of iron oxides. Results A series of in vitro and ex vivo studies demonstrated the ability of mineral‐based products formulated with the new multifunctional coating to provide protection against ultraviolet radiation, high‐energy visible light, infrared radiation, and environmental pollution. Conclusion Newly formulated mineral‐based skincare products provide environmental protection, are ecologically safe, and can replace chemical‐based sunscreen ingredients.
... Ozone found in the stratosphere protects from the harmful effects of UV radiation by filtering almost all UV-C (280-100 nm) and nearly 95% of UV-B (315-280 nm) emitted by the sun. However, ozone minimally filters UV-A (400-315 nm), and for this reason, UV-A accounts for more than 95% of UV light reaching the surface of the Earth [5]. Accordingly, it is relevant to analyze the effect of UV-A rays on polymers properties in order to widen their applications. ...
Article
Full-text available
Among biopolymers, thermoplastic starch (TPS) is a good candidate to obtain biomaterials because of its natural origin, biodegradable character, and processability. Exposure to ultraviolet (UV) radiation causes significant degradation of starch-based materials, inducing photooxidative reactions which result in breaking of polymer chains, production of free radical, and reduction of molar mass. These changes produce a deterioration of TPS mechanical properties, leading to useless materials after an unpredictable time. In this work, changes induced on TPS by UV radiation, analyzing structural properties and mechanical behavior, are studied. TPS was obtained through thermo-mechanical processing of native corn starch in the presence of water (45 % w/w) and glycerol (30 % w/w) as plasticizers. Films were obtained by thermocompression and, before testing, specimens were conditioned to reduce material fragility. Photodegradation process was performed by exposing TPS to 264 h UV radiation in a weathering test chamber. Specimen’s weight loss was determined gravimetrically. Chemical changes were studied by Fourier Transform Infrared Spectroscopy (FTIR) and morphological modifications were analyzed by Scanning Electron Microscopy (SEM). Reduction of weight average molar mass was measured by Static Light Scattering (SLS). Changes in mechanical properties were studied from tensile tests. After 96 h exposure, TPS specimens presented a weight reduction of 4-6%, mainly attributed to plasticizers lost by evaporation. SEM observations showed that UV radiation induced morphological changes on TPS, evidenced by an increment of specimens cracking. By FTIR, it was detected the presence of an additional band located at 1726 cm ⁻¹ in samples submitted to UV radiation, attributed to the formation of-C=O groups. Weight average molar mass of native starch was in the order of 107 g mol ⁻¹ . TPS exposure to UV radiation decreased significantly its molar mass, confirming molecular degradation of the biopolymer. When TPS was exposed during 48 h, it was detected a considerable decrease in elongation at break values (~ 85%), indicating that TPS flexibility was reduced. On the other hand, after 48 h exposure, TPS elastic modulus was 55 times higher than those of the unexposed specimens, evidencing an increase in material rigidity. TPS maximum tensile strength was also increased by UV light, with an increment of ~ 400% after 48 h exposure. Results revealed that starch-based materials can be degraded by exposure to UV radiation, modifying their microstructure and mechanical performance.
... This ultraviolet radiation is a carcinogen to humans that involved in melanoma and non-melanoma skin cancer. 1 UV radiation can be divided into three categories based on its wavelength which include ultraviolet A (UVA), ultraviolet B (UVB) and ultraviolet C (UVC). UVA (320 nm-400 nm) is capable of penetrating the epidermis and dermis of the human skin. ...
Article
Full-text available
Ultraviolet radiation (UVR) from sunlight is an environmental human carcinogen. Skin exposure to UVR would increase the oxidative stress, deoxyribonucleic acid (DNA) damage, melanogenesis and photocarcinogenesis. Therefore, development of photoprotective agent is necessary in order to reduce the cutaneous toxicity. The use natural active compounds like stilbenes and its derivatives have gained attention as photoprotection to skin due to its broad biological activities such as antioxidant, anti-inflammatory, anti melanogenesis and chemoprevention. This review article aims to analyse the existing literature on the photoprotective effect of stilbenes and its derivatives which include the resveratrol, pterostilbene, piceatannol and oxyresveratrol on in vitro and in vivo studies. This article describes the stilbenes and its derivatives protect and prevent UVR induced skin disorders via the reduction of oxidative stress, alleviation of DNA damage, inhibition of melanogenesis and anti photocarcinogenic effect.
... They disrupt the antioxidative system in the skin (3), and can cause immune suppression, cancer, and skin aging (25). Catalase is a representative parameter of oxidation in epidermal tissue that can suppress active oxygen activity (26). In a previous study, we revealed that CAPS has an effect against the antioxidation induced by UV radiation in the human skin (27). ...
Article
Blackcurrants (Ribes nigrum L.) have various benefits for human health. In particular, a polysaccharide derived from blackcurrant was found to be an immunostimulating food ingredient in a mouse model. We named a polysaccharide derived from blackcurrant cassis polysaccharide (CAPS). In a previous clinical study, we reported that CAPS affects skin dehydration, demonstrating its effectiveness against skin inflammation was related to atopic dermatitis; skin inflammation caused skin dehydration. However, there are no studies regarding CAPS effectiveness against skin dehydration. The current study aimed to investigate CAPS effectiveness against skin dehydration. We further demonstrate the effect of oral administration of CAPS on skin dehydration caused by ultraviolet (UV) irradiation-induced inflammation in mice. We found that CAPS administration suppresses skin dehydration caused by UV irradiation. We also found that CAPS decreases interleukin-6 and matrix metalloproteinase transcription levels in the mouse skin. These results show that CAPS improves skin hydration in UV-irradiated mice.
... Nonmelanoma skin cancer (NMSC) occurs in all races worldwide, and more than two million new cases are diagnosed annually in the USA alone. Extensive epidemiologic, clinical, and biological studies have proven that ultraviolet B (UVB) radiation is the major cause of NMSC [1][2][3][4][5]. Despite significant risk mitigation by the application of sunscreens, a substantial part of the population remains subjected to increasing UVB exposure due to occupational hazards, recreational activities, and climate changes, causing a continued rise in the NMSC incidence [6]. ...
Article
Full-text available
We have previously demonstrated that apigenin promotes the expression of antiangiogenic protein thrombospondin-1 (TSP1) via a mechanism driven by mRNA-binding protein HuR. Here, we generated a novel mouse model with whole-body THBS-1 gene knockout on SKH-1 genetic background, which allows studies of UVB-induced acute skin damage and carcinogenesis and tests TSP1 involvement in apigenin's anticancer effects. Apigenin significantly inhibited UVB-induced carcinogenesis in the wild-type (WT) animals but not in TSP1 KO (TKO) mice, suggesting that TSP1 is a critical component of apigenin's chemopreventive function in UVB-induced skin cancer. Importantly, TKO mice presented with the elevated cutaneous inflammation at baseline, which was manifested by increased inflammatory infiltrates (neutrophils and macrophages) and elevated levels of the two key inflammatory cytokines, IL-6 and IL-12. In agreement, maintaining normal TSP1 expression in the UVB-irradiated skin of WT mice using topical apigenin application caused a marked decrease of circulating inflammatory cytokines. Finally, TKO mice showed an altered population dynamics of the bone marrow myeloid progenitor cells (CD11b+), with dramatic expansion of the population of neutrophil progenitors (Ly6ClowLy6Ghigh) compared to the WT control. Our results indicate that the cutaneous tumor suppressor TSP1 is a critical mediator of the in vivo anticancer effect of apigenin in skin, specifically of its anti-inflammatory action.
... Changes in several diferent genes are usually needed for a cell to become cancerous. Damage of DNA may be in the form of inherited genetic mutation, but in most cases it occurs gradually over the life due to the inluence of environmental factors, such as UV rays from the sun [10][11][12]. ...
... Exposure to ultraviolet (UV) radiation is known to cause eye diseases such as cataracts, macular degeneration, and pterygium. UV exposure is also closely related to the development of various skin diseases, including skin cancer [1,2]. Sunlight contains a large proportion of UV-A rays, most of which are absorbed by the epidermis; however, about 10% of UV-A radiation can penetrate the subcutaneous layer [3]. ...
... It has been proposed that a history of KC is a marker for previous UV exposure, 21 which would explain both the increased incidence and diagnosis of lethal and nonlethal melanoma. 22 However, a population-based study of survival after a melanoma diagnosis suggests that some factors associated with high levels of sun exposure, such as solar elastosis and, to a lesser extent, sunburns and intermittent sun exposure, are inversely associated with death from melanoma. 23 Our data were consistent with this finding. ...
Article
Full-text available
Background: Previous studies have found an increased risk of invasive cutaneous melanoma (CM) among those with a history of keratinocyte carcinoma (KC). Objective: The aim of this study is to evaluate the risk of CM death after KC. Methods: The study was based on the Health Professionals Follow-up Study (HPFS). Cox proportional hazards model was used to examine the hazard ratio (HR) of CM death associated with personal history of KC, among the entire study population (primary analysis) and invasive CM cases (secondary analysis) respectively. Results: We documented a total of 908 invasive CM cases over a total of 0.7 million person-years of follow-up. Among all participants, the risk of developing either lethal or non-lethal invasive CM increased for those with KC history. The risk of melanoma death based on KC history was non-significantly increased, with HR (95% CI) of 1.53 (0.95 - 2.46). In the case-only analysis, those with KC history had a significantly lower risk of melanoma death compared with those with no such history, HR=0.60 (0.35-0.94). Limitations: Because HPFS consists exclusively of male health professionals, the results of this study may not be extended to the entire population. Conclusion: Personal history of KC is associated with a decreased risk of melanoma-specific death among male patients with invasive CM.
... As a result of DNA damage, many cytokines and inflammatory mediators accumulate in the skin. 6 Antioxidants are substances that can eliminate oxidative damage to a particular target molecule, prevent, slow down and neutralize free radicals for example by breaking the chain reaction of free radicals. 7 Based on the source, antioxidants consist of natural and artificial antioxidants. ...
Article
Full-text available
Background: Indonesia is an archipelagic tropical country that get sun exposure all the time. Exposure to radiation can cause acute effects in the form of erythema through the inflammatory process. Antioxidants are substances that can protect the body from damage caused by ROS. Natural antioxidants can be found in vegetables and fruits, one of which comes from lemon extract (Citrus limon L.). Lemon extract is known to have active compounds in the form of flavonoids and phenols which can act as antioxidants. The aim of this research was to determine the protective effect of lemon extract on UVB exposure in the skin of male wistar rats. Methods: This research used the true experimental posttest only control group design method. Samples were divided into three treatment concentrations, namely ethanol extract of lemon 5%, 10%, and 20%. Result: After testing for normality, the significance value was obtained (p <0.05). Based on the results of the normality and homogeneity test, the results of the data distribution are not normal and the homogeneous tests of the hypotheses used are the Kruskal-Wallis non-parametric test. Kruskal-Wallis non-parametric test results showed a significant difference with the significance value (p = 0.001). The best degree of erythema score was found in the cream of 10% ethanol extract of lemon with an average of 0.8 ± 0.84. Conclusion : The ethanol extract of lemon (Citrus limon L.) cream in a certain dosage has a significant effect on reducing the erythema degree score in the back skin of male Wistar rats (Rattus norvegicus) after exposure to UVB rays.
... Therefore, environmental changes that increase UV radiation transmission have a direct impact on human health. Hence, a history of sunburn and extensive sun exposure is directly related to the relative risk of melanoma during life (10,11). ...
Article
Full-text available
Background: Exposure to radiation is a major risk factor for skin cancer so that 65 to 90% of skin cancers can be attributed to the exposure with sunlight. Objectives: The current study aimed to investigate the association between the human development index and the incidence of UV-related melanoma. Methods: This is an ecological study. Data on the incidence of UV-induced melanoma were extracted from the GLOBOCAN estimates (GLOBOCAN 2012), and data on the human development index were extracted from the World Health Organization (WHO) database. Data analysis was conducted by Stata software (Ver. 14). The descriptive analysis involved mean and standard deviation. The correlation method was used to evaluate the association between the population attributable fraction (PAF) of melanoma for ultraviolet (UV) and the HDI components. A P value < 0.005 was considered as statistically significant. Results: The results revealed a significant positive association between UV-attributable melanoma cancer and HDI in women (r = 0.401, P < 0.0001), men (r = 0.488, P < 0.0001), and both sexes (r = 0.455, P < 0.0001). In Americas (r = 0.452, P < 0.05) and Europe (r = 0.740, P < 0.05), a significant positive correlation was observed between UV-induced melanoma and HDI, but this association was not significant in Asia (P > 0.05). In Africa, a negative correlation was observed, though it was not statistically significant (r = -0.301, P > 0.05). The results of the analysis of variance (ANOVA) showed a significant statistical relationship between the incidence of UV-related melanoma and the levels of development (F = 25.1, P < 0.0001) so that the higher the score of HDI, the higher the incidence of this cancer. Conclusions: Since there is a positive correlation between UV-related melanoma and HDI, further attention should be paid to this risk factor, especially in countries with a high HDI to reduce the UV-induced melanoma cancer.
... UVR plays a key role in cSCC carcinogenesis by inducing DNA mutations and escaping from immune surveillance. 24 DNA mutations caused by UVR in skin cancers include inactivation of tumour suppressor genes (p53, CDKN2A and PTCH) or activation of proto-oncogenes (Ras). These genes are regulators of the cell cycle and when altered are able to induce tumorigenic effects. ...
Article
Full-text available
The incidence of cutaneous squamous cell carcinoma (cSCC) is rapidly increasing. A growing part of this patient group is formed by immunocompromised patients, for example organ-transplant recipients (OTR). Although over 90% of the cSCC show a relatively harmless clinical behaviour, there is also a chance of developing advanced cSCC and metastases. Locally advanced cSCC are defined as cSCC that have locally advanced progression and are no longer amenable to surgery or radiation therapy. Better understanding of the clinical behaviour of cSCC is essential to discriminate between low- and high-risk cSCC. Staging systems are important and have recently been improved. Genetic characterisation of SCC will likely become an important tool to help distinguish low and high-risk cSCC with an increased potential to metastasise in the near future. Available treatments for high-risk and advanced cSCC include surgery, radiotherapy, chemotherapy and targeted therapy with epidermal growth factor receptors inhibitors. Anti-PD-1 antibodies show promising results with response rates of up to 50% in both locally advanced and metastatic cSCC but, in its present form, is not suitable for OTR.
... (39). The carcinogenesis of UV radiation is multimodal, involving direct DNA damage, inflammation, and immune suppression (40). Notably, UVB radiation causes a characteristic DNA mutation (particularly in the gene encoding tumor suppressor p53) termed "signature 7" in keratinocytes by generating cyclobutene pyrimidine dimers that undergo transition mutations at cytosine bases (i.e., C:G>T:A transitions and CC:GG>TT:AA double-nucleotide substitutions) (41,42). ...
Article
Recent large-scale GWAS and large epidemiologic studies have accelerated the discovery of genes and environmental factors that contribute to the risk of keratinocyte carcinoma (KC), which includes basal cell carcinoma (BCC) and squamous cell carcinoma (SCC). This Review summarizes the genomic regions associated with SCC and BCC risk, examines the genetic overlap between SCC and BCC, and discusses biological pathways involved in SCC and BCC development. Next, we review environmental factors that are associated with KC risk, including those that are shared between SCC and BCC as well as others that associated with only one type of KC. We conclude with a critical appraisal of current research and potential directions for future research.
... Melanoma is a malignant tumour arising from melanocytes. 1 It causes the greatest number of skin-cancer-related deaths worldwide, and despite the recent advances in therapeutic strategies, its prognosis in advanced stages remains poor. 1 The environmental determinants of melanoma remain elusive, although a well-known risk factor is sun exposure. 2,3 In the past 10 years, it has become increasingly evident that in addition to our genome, health status depends on complex interactions with our symbiotic microbial community (the microbiota) and the genes and functions associated with it (the microbiome). The human microbiota is emerging as a crucial player in several types of cancer, and is an excellent predictor of the outcome of cancer immune checkpoint therapy. ...
Article
Full-text available
Background: The microbiome is emerging as a crucial player of the immune checkpoint in cancer. Melanoma is a highly immunogenic tumour, and the gut microbiome composition has been correlated to prognosis and evolution of advanced melanoma and proposed as biomarker for immune checkpoint therapy. Objectives: We investigated the gut fungal and bacterial composition in early-stage melanoma and correlated microbial profiles with histopathological features. Methods: Bacterial 16S rRNA and fungal ITS region sequencing was performed from faecal samples of patients affected by stage I and II melanoma, and healthy controls. A meta-analysis with gut microbiota data from metastatic melanoma patients was also carried out. Results: We found a combination of gut fungal and bacterial profiles significantly discriminating M patients from controls. In melanoma patients, we observed an abundance of Prevotella copri and yeasts belonging to the Saccharomycetales order. We found bacterial and fungal community correlated to melanoma invasiveness, whereas specific fungal profile correlated to melanoma regression. Bacteroides was identified as general marker of immunogenicity, being shared by regressive and invasive melanoma. In addition, the bacterial community from stage I and II patients were different in structure and richer than those from metastatic melanoma patients. Conclusions: Gut microbiota composition in early-stage melanoma changes along the gradient from in situ to invasive (and metastatic) melanoma. Changes in the microbiota and mycobiota are correlated to the histological features of early-stage melanoma, and to the clinical course and response to immune therapies of advanced stage melanoma, through a direct or indirect immunomodulation.
... Since 2009, indoor tanning beds have been classified as a class I carcinogen by the World Health Organization [27], as UV radiation is a known risk factor for the development of skin cancer [28][29][30][31], with one study attributing nearly 95% of all cases of melanoma to be related to UV exposure [32]. Following their diagnosis, our ARR analyses did not reveal a statistically significant difference in tanning bed use, always protecting themselves from the sun, nor in women suffering one or more sunburns in the past 12 months-in fact, male skin cancer survivors were statistically more likely to have prolonged UV exposure resulting in a burn. ...
Article
Full-text available
Purpose With the continued increase in skin cancer incidence rates, the population of skin cancer survivors continues to grow. Understanding skin cancer survivors’ lifestyle behaviors, including ultraviolet radiation exposure, is important in reducing skin cancer recurrences and improving health outcomes. The objective of this study is to compare the differences in lifestyle behaviors among skin cancer survivors or individuals who currently have skin cancer versus individuals who have never had a skin cancer diagnosis. Methods To investigate these lifestyle behaviors, we performed a cross-sectional analysis comparing lifestyle behaviors in persons diagnosed with skin cancer and those without a history of skin cancer among US citizens using publicly available data from the 2018 Behavior Risk Factor Surveillance System (BRFSS). Results In total, there were 437,436 respondents. No significant difference existed between the two cohorts in sunburn frequency, use of sun protection, or indoor tanning; in fact, males were more likely to be afflicted with sunburns following diagnosis. Skin cancer survivors were less likely to be current smokers and sedentary. Female survivors were more likely to binge and heavily drink alcohol. Conclusion Our findings highlight important areas for reducing risk factors, which could reduce the recurrence of skin malignancies in skin cancer survivors. Implications for Cancer Survivors Our study provides insight to lifestyle behaviors among skin cancer survivors. Being aware of these behaviors has the potential to reduce skin cancer recurrence.
... From the wide spectral band, UV radiation in particular is an important part of the electromagnetic radiation that has a profound influence on organic life and inorganic existence. [5][6][7][8] The source of UV radiation is not only limited to sunlight, but it can also be artificially generated from phototherapy, plasma torches, UV light emitting diodes, welding arcs, and xenonmercury arc lamps. The UV band is defined as the spectral range of 10 nm to 400 nm according to the ISO standard. ...
Article
Clouds in the sky pass almost 80% of ultraviolet (UV) radiation to the earth's surface, which has a significant impact on humankind. Conventional UV photodetectors (PDs) require an external battery, which not only increases the device size but also has a limited life span and maintenance costs can be prohibitively expensive. An alternative and more technically-sound solution would be the use of self-powered UV PDs that can operate independently, eliminating the need for an external source. Although many exciting studies have been done and state-of-the-art research is underway to successfully fabricate self-powered UV PDs, periodic reviews on this topic are deemed essential so that the technology's readiness can be properly evaluated and critical challenges can be addressed in a timely manner. In this article, the key issues and most exciting developments made in recent years on built-in electric field assisted self-powered UV PDs based on p-n homojunctions, p-n heterojunctions, and Schottky junctions followed by energy harvester integrated UV PDs are extensively reviewed. Finally, a summary and comparison of different types of self-powered UV PDs as well as future challenges that need to be addressed are discussed. This review sets a foundation providing essential insights into the present status of self-powered UV PDs with which researchers can engage and deal with the major challenges.
... Sunscreen agents are increasingly used due to their ability to minimize cellular damages caused by the sun's UV radiation and thus reduce the risks of developing skin cancers (Mancebo and Wang, 2014). Benzophenones (BPs) are a class of broad-spectrum ultraviolet absorbent chemicals with a high absorption rate and good photo-thermal durability. ...
Article
Introduction Surface disinfection is one of the key points to reduce the risk of transmission both in healthcare and other public spaces. A novel UV-chip disinfection technology is presented. Technological, photonic and microbiocidal characteristics are evaluated taking as reference an ultraviolet-C (UV-C) LED source of equivalent radiant power. Methods The UV chip has a circular radiating surface with a diameter of 1.3 cm, emitting UV cold light at about 5 mW and driven current of about 80 µA. Four bacterial strains were used to conduct the microbiological tests at 4°C and 60°C to evaluate the bactericidal performance of the two technologies under the same operating conditions. Results Spectral differences were found between the UV-C LED and the chip, with an emission curve strictly around 280 nm and a broader band centred around 264 nm, respectively. Between-technology microbiological inactivation levels were comparable, achieving total abatement (99.999%) in 8 min at 7.5 cm. Discussion The UV chip exhibits unique properties that make it applicable in some specific contexts, where UV-C LEDs present the most critical issues. Besides, it is portable and exhibits a broad spectrum of UV wavelengths with a peak where the maximum microbiocidal efficacy occurs. Important issues to be addressed to improve this technology are the high voltage management and the too low energy efficiency. Conclusion This cold emission technology is virtually unaffected by changes in ambient temperature and is particularly useful in short-distance applications. Recent developments in technology are moving towards a progressive increase in the chip’s radiant power.
Article
The Ultraviolet (UV) radiation is emitted by the sun and is part of the electromagnetic spectrum. There are three types of UV rays (UV-A, UV-B and UV-C), however only UV-A and UV-B have biologic effects in humans, with UV-B radiation being primarily responsible for these effects. Among the measures of photoprotection advised by the health authorities, the topical application of sunscreens (containing UV-B filters) is the preferred worldwide. Currently, octylmethoxycinnamate (OMC) is the most commonly used UV-B filter in sunscreens. Their application has proven to be effective in preventing burns, but its efficiency against melanoma continues under intense controversy. Studies have shown that OMC behaves like an endocrine disruptor, altering the normal functioning of organisms. However, few studies have evaluated their multiple hormonal activities. Some studies suggest that the OMC exerts an estrogenic, anti-androgenic, anti-progestenic and anti-thyroid activity. But, through what mechanisms? In humans, few studies were performed, and some questions remain unclear. Thus, the purpose of this review is to present the multiple hormonal activities established for the OMC, making a critical analysis and relationship between the effects in cells, animals and humans.
Article
Full-text available
Exosomes are small extracellular vesicles with sizes ranging from 30 to 150 nanometers, containing proteins, lipids, mRNAs, microRNAs, and double-stranded DNA derived from the cells of origin. Exosomes can be taken up by target cells, acting as a means of cell-to-cell communication. The discovery of these vesicles in body fluids and their participation in cell communication has led to major breakthroughs in diagnosis, prognosis and treatment of several conditions (e.g., cancer). However, the conventional isolation and evaluation of exosomes, and their microRNA contents, suffers from high costs, lengthy process, difficult standardization, low purity, and poor yield. In this regard, the emergence of microfluidic devices, which show increased efficiency in sieving, trapping, and immunological separation of small volumes, could provide improved detection and monitoring of exosomes involved in cancer. Microfluidic techniques hold promise for further advances in the development of diagnostic and prognostic devices. This review covers ongoing research on microfluidic devices for the detection of microRNAs and exosomes as biomarkers, and looks forward to their translation to point-of-care and clinical applications.
Article
In this Letter, a transparent organic photodetector (OPD) with a property of ultraviolet sensitivity is demonstrated by using an inverted architecture. A conjugated polymer of ploy [(9,9-bis(3′-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctyl)fluorene)] is introduced to modify the energy level and morphology between ZnO and organic optoelectronic material. As a result, at a wavelength of 350 nm and a bias of −1 V, the photodetectivity of 1012 Jones from both sides of the transparent device is obtained with a working area of 1 cm2. Moreover, an optical simulation is applied to analyze the optical electric field distribution inside the OPD.
Article
Full-text available
Cancer is the largest cause of death worldwide, with 10 million deaths projected in 2020. Cancer is only diagnosed after it has spread to other parts of the body. It is possible to cure cancer cells if they are detected at an early stage. Unfortunately, many tumors are not detected until they become severe. Annually, almost 8.2 million people die from cancer as a result of ineffective monitoring and diagnosis. However, there are currently no recognized diagnostic approaches that do not harm patient's physical health during the cancer testing phase. Cells multiply too quickly in malignant conditions. A fraction of the cells will always die and shed genetic material into the bloodstream, interacting with greater amounts of DNA fragments from regular cell death. Cancer-causing mutations in DNA fragments can be found freely floating in the blood of cancer patients. cfDNA is the name given to these segments. Cancer patients have higher cfDNA levels than healthy people. cfDNA is comprised of fragmented DNA which cells release into the bloodstream, usually as a result of cell death. cfDNA found in healthy patients' plasma is usually made of germaline DNA released by normal cells. In cancer patients, some of the maximum cfDNA is made up of DNA released by tumor cells, which are referred to as circulating tumor DNA (ctDNA). Thus, in this article we are focusing on the methods used for screening of early stage cancer through blood analysis. This method is easy to diagnose cancer without causing harm to the patient's physical health.
Article
Thermal environment influences human thermal comfort significantly when people have outdoor activities. Four environmental parameters determine outdoor thermal comfort, which are air temperature, relative humidity, wind speed, and solar radiation. It is noteworthy that, different from the indoor environment, solar radiation significantly affects outdoor thermal comfort, which needs to be comprehensively understood and analyzed. In this paper, we focused on thermophysiological models and thermal comfort models with consideration of solar radiation, applications of these models, and discussed existing problems and future potential works. Here, those key points are summarized: (1) Many comprehensive thermophysiological models for simple and complex body models have been put forward. For solar load on the human body, Fanger's model showed a good fitting degree in predicting absorbed solar radiation. (2) Existing thermal indexes may not be suited to dynamic conditions of solar radiation while the DTS model may be a good example for thermal comfort evaluation under dynamic solar radiation. (3) For temporary conditions, non-Fourier models, such as the dual phase-lag model, may be applied in thermophysiological models due to the non-uniform internal structure of biological tissues. (4) A scheme of establishing dynamic thermal comfort models is put forward, considering dynamic features of environment parameters, thermophysiological parameters, and thermal adaptation.
Article
Age-related macular degeneration (AMD) is a major cause of blindness in elderly. It is characterized by the loss of central vision due to damaged retinal pigment epithelial (RPE) cells and photoreceptors. Blue Light (BL) exposure was proposed as a risk factor for AMD progression. We undertook this study to determine the effects of BL on the behaviour of RPE cells and their potential mitigation by BL-filtering intraocular lenses (IOL). Human RPE cells were exposed or not to BL, with the absence or presence of either a clear ultraviolet (UV)-filtering IOL (CIOL), or a yellow UV- and BL-filtering IOL (YIOL). Cells were analyzed for their oxidative stress by measuring the levels of reactive oxygen species (ROS), and their viability. BL exposure significantly increased the levels of both total cellular and mitochondrial ROS. While this increase was not affected by placing the CIOL in the BL beam, YIOL decreased the levels of both ROS reservoirs. Increased ROS production was accompanied by increased cell death which was similarly decreased when cells were protected with the YIOL. Pre-treatment of cells with N-acetylcycteine (NAC) abolished the increased cell death, suggesting that the effects of BL on cell viability were mainly due to increased levels of ROS. BL is deleterious to RPE cells due to increased oxidative stress and cell death. These effects were mitigated by filtering these radiations. The use of BL-filtering devices may represent a strategy to reduce these effects on RPE cells and delay the onset of AMD.
Article
Clothing is recognized by leading health agencies as a primary method to protect against the harmful effects of photodamage caused by ultraviolet (UV) radiation and visible light. The photoprotective capacity of clothing is commonly measured as the ultraviolet protective factor (UPF). While the technology driving photoprotective clothing has been well‐established, there continues to be efforts to discover new materials to improve the UPF of clothing. Here, we show increased Google searches for photoprotective clothing over the last decade, suggesting a high level of public interest in photoprotective clothing. In addition, we investigate the frequency of UPF‐graded photoprotective clothing sold by large retail stores featured in Fortune 1000. We review factors that alter the UPF of clothing and describe emerging textile technologies used to increase clothing’s photoprotective capacity. Finally, we compare how photoprotective clothing is regulated among different countries, the importance of photoprotective clothing in occupational health, and research in visible light and clothing photoprotection.
Article
Background The incidence of nonmelanoma skin cancer (NMSC) exceeds the incidence of all other types of cancers combined. Cumulative sun exposure and intermittent sun exposure are known risk factors for the development of NMSC. Because obesity has been shown to decrease the risk of NMSC incidence, this study investigated whether the risk of NMSC with sun exposure was consistent across different levels of body size. Methods Body size was assessed with the body mass index (BMI) and the waist‐to‐hip ratio (WHR). Sun exposure was assessed in watts and langleys and by the amount of time spent outdoors per day in the summer during a person’s 30s. Results Among 71,645 postmenopausal women eligible for inclusion in this study, 13,351 participants (18.6%) developed NMSC. A BMI ≥ 25 kg/m² or a WHR ≥ 0.80 was associated with lower NMSC hazard rates (hazard ratio for BMI, 0.78; hazard ratio for WHR, 0.89); however, the association between higher levels of sun exposure and a higher risk of NMSC was more apparent among women with a BMI ≥ 25 kg/m² or a WHR ≥ 0.80 in comparison with those of a normal weight (P for interaction for BMI < .001; P for interaction for WHR = .022). Conclusions Although most studies have considered sun exposure as a covariate, none have addressed the potential interaction of body size with sun exposure; therefore, the effect size of being overweight or obese may have been overestimated. In comparison to the normal‐weight group, those in the overweight group had increasingly higher hazard rates with increasing sun exposure. Further studies are warranted to investigate how increased weight interacts with sun exposure to influence skin cancer pathogenesis.
Article
Al–N codoped ZnO heterojunction diodes were grown on n–Si (100) substrates using radio frequency (RF) magnetron sputtering with different flow rates of N2 reactive gas (5–18 sccm). X-ray diffraction results revealed that codoped ZnO thin films have wurtzite structure with crystallite size 25–31 nm. Scanning electron micrographs revealed that all thin film samples have agglomerated flakes type surface morphology. The optical band-gap determined using UV–Vis transmission spectra was found increased with increasing the flow rate of N2. The current-voltage (I–V) measurements were performed in dark and illumination condition using UV light (wavelength 365 nm) for photodetection application. The high stability and fast switching UV photoresponse behaviour was obtained for p-ZnO/n–Si. The maximum responsivity 0.16 A/W was obtained at 3.2 mW/cm² illumination of the UV light (365 nm) at 5 V bias voltage.
Chapter
This chapter discusses the known causes of cancer to suggest preventative measures that can be taken by individuals, societies, or governments to decrease cancer prevalence. The causes of cancer discussed in the chapter include: genetic (somatic and inherited), epigenetic, viral, and environmental. As opposed to genetic alterations, which directly change the way cells express genes due to direct mutations within the gene, epigenetic alterations modulate the way a gene is expressed through other mechanisms. Certain viruses are also known to cause cancers, with six distinct human viruses currently termed oncogenic. Some of these viruses are now the most preventable causes of cancer with the invention of safe and effective anti‐ human papillomaviruses vaccines, which provide long‐term immunization from these viruses. The chapter summarizes the concept of microenvironment‐driven oncogenesis, and tumor heterogeneity and clonality, important tumor properties that make these exceedingly evasive.
Article
Prolonged exposure of the skin to ultraviolet radiation (UV) leads to its damage and loss of protective properties. This condition called photoaging of the skin is caused by a number of destructive factors, such as reactive oxygen species (ROS) and proteolytic enzymes that cause damage to the extracellular matrix, e.g. collagen fibers. Many cells of the immune system, including neutrophils, are involved in the photoaging process. The presence of neutrophils in the skin exposed to UV irradiation is known; however, the mechanism of neutrophil activity at these conditions remains unclear. In our study, we focused on the ability of neutrophils to release neutrophil extracellular traps (NETs) and the role of these structures in the photoaging process. NET release occurs in response to various stimuli; however, we hereby showed that the UVA and UVB radiation that reaches the Earth's surface could activate the mechanism of netosis. UV-induced netosis was much faster than that activated by chemical or biological factors; however, it also occurred due to the production of ROS, known signal mediators in netosis. In this work, we also identified the probable netosis signaling pathway involved in the neutrophil response to UV. The participation of NET components may explain the ongoing process of skin photoaging, but it is also important to indicate netosis as a potential target for skin protection therapy. Antioxidants tested in this work, such as N-acetylcysteine, ethamsylate, as well as vitamin B1 (thiamine), can successfully inhibit UV-induced netosis, and thus be used as protective components against the negative effects of solar radiation.
Article
Objective The objective of this work was to develop a peptide production process of the exact molecular weight propitious to topical application for cosmetics and to investigate the effects of enzymolysis-derived peptide on UVB-induced photoaging rat skin. Methods The chum salmon fish skins were hydrolyzed by alkaline protease and neutral protease and spray-dried at different conditions, and three kinds of molecular weight peptide (MFSOP) were obtained. A total of 66 ICR rats (female, 20 ± 1 g) were randomly divided into eleven groups, including the normal, model, and experimental groups. The three kinds of MFSOP were dissolved at different dosages (5‰, 2.5%, and 5%) and then applied on the ICR hairless back skins prior to exposing UVB irradiation of 3000mJ/cm² to them 4 h later. After 8 weeks, the rats were killed and the hair-shaved skins were tested for skin moisture, hyaluronic acid, hydroxyproline, antioxidant activity, and RNA expression. Results Three kinds of MFSOP were obtained, with the average molecular weights of 495.16, 1194.00, and 2032.46 Dalton, respectively. The MFSOPs, especially the MFSOP of average molecular weight of 1194.00 Dalton, played an important role in the recovery of the UVB-injured skin tissue in lock in moisture, in antioxidant activity and in promotion in collagen and elastin protein to some extent. Conclusion MFSOPs, especially MFSOP of average molecular weight of 1194.00 Dalton, derived from enzymolysis are potential materials to apply in cosmetics for the UVB9-induced anti-photoaging activity (lock in moisture, antioxidant activity, and promotion in collagen and elastin protein).
Chapter
Advocacy and political action will play a major role in improving access to dermatologic care in rural areas. While access to care is limited for patients with dermatologic disease in many parts of the United States, rural locations are most severely affected. This is demonstrated by delays in diagnosis and treatment, longer wait times to see a clinician, and less frequent follow-up visits with providers. This chapter provides a detailed blueprint for best practices in building a successful political action plan to advance a policy agenda. This is followed by case studies that demonstrate the effectiveness of this process in achieving public funding for impactful programs, reforming regulations, and enacting state laws. It is hoped that this will motivate dermatologists to political action as they gain confidence that this work, however long and arduous, can have a significant impact on dermatologic patients.
Article
Solar-blind ultraviolet (UV) photodetectors are greatly desired in a number of areas in terms of military and civilian purposes, especially self-powered devices driven by the photovoltaic effect. Herein, a solar blind photodetector has been successfully achieved on a spiro-MeOTAD/β-Ga2O3 organic–inorganic hybrid construction. The fabricated photodetector can operate with a self-powered mode and shows an obvious photodetection with a narrow spectrum region, exhibiting a high responsivity (65 mA W−1) and a large external quantum efficiency (32%) under low power intensity (∼1 μW cm−2) UV illumination, at zero bias. Fortunately, the device shows a fast temporal pulse response (τrise ∼ 2.98 μs and τdecay ∼ 28.49 μs), which is superior to the previously reported Ga2O3 based self-powered photodetectors. More importantly, the photodetector can operate stably and shows good repeatability. These excellent performances of the device could be attributed to the pre-existing band alignment of the Ga2O3 and spiro-MeOTAD, and are comparable to and/or even higher than those of other self-powered solar-blind UV photodetectors, which indicates that a device configuration based on a Ga2O3/spiro-MeOTAD heterojunction is certified as an excellent candidate for a high sensitivity, ultrafast response and self-powered photo-detecting device for solar-blind UV signals.
Article
Background The COVID19 epidemic highlighted the importance of air in the transmission of pathogens in the air. Air disinfection is one of the key points to reduce the risk of transmission both in the health sector and in public, civil and industrial environments. All bacteria and viruses tested to date can be inactivated by UV-C rays. Laboratory tested UV-C systems are increasingly popular and proposed as effective technologies for air purification; few studies have evaluated their performance in populated indoor environments. The aim of this investigation was to evaluate the effectiveness of a UV-C disinfection system for air in a real working context. Methods This experimental study was conducted between December 2020 and February 2021 in an office of the Department of Molecular and Developmental Medicine of the University of Siena, Italy. A pre-final version air purifier (Cleaning Air T12), capable of treating 210 m³/h of air, was first tested for its ability to filter particulates and reduce microbial air contamination in the absence of people. Subsequently, the experiments were conducted in the presence of 3–5 subjects who worked for several hours in an office. During the tests, microbiological samples of air were collected in real time, switching the system on and off periodically. Air samples were collected and incubated on Petri dishes at 36 °C and 22 °C. Statistical analysis was performed with Stata 16 software assuming a significance level of 95%. An interpolating model was identified to describe the dynamics of contamination reduction when the device operates. Results Preliminary tests showed a significant 62.5% reduction in Colony-Forming Units (CFUs) with 36 °C incubation. Reductions in the particulate component were also observed. In the main test, comparison of CFU data, between the device-on phase (90 min) and the subsequent device-off phase (60 min), showed statistically significant increase (p = 0.001) of environmental contamination passing from a mean of 86.6 (65.8–107.4) to 171.1 (143.9–198.3) CFU/m³, that is an rise of about 100%. The interpolating model exhibited a good fit of CFU reduction trend with the device on. Conclusions The system, which mainly uses UV-C lamps for disinfection, was able to significantly reduce environmental and human contamination in real time. Experimental tests have shown that as soon as the device is switched off, after at least half an hour of operation, the healthiness of the air decreases drastically within 10 minutes, bringing the airborne microbial contamination (induced by the presence of operators in the environment) to levels even higher than 150% of the last value with the device on. Re-engineering strategies for system improvement were also discussed.
Article
Objective Essential oil derived from the rhizome of Curcumin longa (CL-EO) has marked anti-inflammatory, antioxidant, antimicrobial, anticancer, and antiviral activities. However, its effect on photodamaged skin has not yet been evaluated. In this study, the anti-skin photoaging activity of CL-EO was determined by performing an ultraviolet B (UVB)-induced skin aging assay. Methods CL-EO was extracted by hydrodistillation and characterized using gas chromatography–mass spectrometry. The anti-skin aging effect was determined by topically applying 150 μl of CL-EO diluted to 1, 5, and 10% with ethanol to the dorsal area of UVB-irradiated nude mice every day except on Sunday for 8 weeks. Histological and immunohistochemical analyses were performed. Results In total, 56 compounds, which accounted for 94.36% of the contents of CL-EO, were detected. The major compounds in CL-EO were ar-turmerone (36.04%), curlone (8.78%), β-turmerone (7.05%), 8,9-dehydro-9-formyl-cycloisolongifolene (5.69%), β-sesquiphellandrene (5.39%), germacrone (4.51%), ar-curcumene (2.19%), α-himachalene (2.14%), and ledane (2.13%). Hematoxylin and eosin staining of tissue sections revealed that CL-EO decreased epidermal skin thickness. Immunohistochemistry showed that CL-EO inhibited interleukin-1β and tumor necrosis factor-α expression. Conclusions Thus, CL-EO can reduce cutaneous photoaging in a UVB-irradiated nude mouse model. Therefore, CL-EO could be used in the formulation of skin care and functional cosmetic products.
Article
The increasing incidence of skin cancer (SC) is a global health concern. The commonly reported side effects and resistance mechanisms have imposed the pursuit for new therapeutic alternatives. Moreover, additional preventive strategies should be adopted to strengthen prevention and reduce the rising number of newly SC cases. This review provides relevant insights on the role of p53 tumour suppressor protein in melanoma and non-melanoma skin carcinogenesis, also highlighting the therapeutic potential of p53-targeting drugs against SC. In fact, several evidences are provided demonstrating the encouraging outcomes achieved with p53-activating drugs, alone and in combination with currently available therapies in SC. Another pertinent perspective falls on targeting p53 mutations, as molecular signatures in premature phases of photocarcinogenesis, in future SC preventive approaches. Overall, this review affords a critical and timely discussion of relevant issues related to SC prevention and therapy. Importantly, it paves the way to future studies that may boost the clinical translation of p53-activating agents, making them new effective alternatives in precision medicine of SC therapy and prevention.
Article
To solve the poor absorbance on ultraviolet A (UVA) radiations and dark color, alkali lignin (AL) was modified via atom transfer radical polymerization (ATRP) grafting of 2-4-benzoyl-3-hydroxyphenyl acrylate (BHA). The color of AL was whitened 86% and the UVA/UVB absorbance ratio of AL-g-BHA improved to 1.2, while the reported highest value was 0.9. The excellent UV-blocking performance of AL-g-BHA was demonstrated in sunscreen. Sun protection factor (SPF) value of the sunscreen containing 10 wt% of optimal AL-g-BHA reached 59. Nanoscale AL-g-BHA normal and reverse micelles (LBNM and LBRM) were fabricated to investigate the effect of microstructure on the sunscreen performance. When BHA chains were packed inside, the SPF value of sunscreen containing 10 wt% of LBNM decreased to 28. In contrast, the SPF value of sunscreen containing 10 wt% of LBRM with BHA chains distributing on the surface was up to 244. Both AL-g-BHA and corresponding micelles exhibited good biocompatibility.
Article
UV ray detection near the earth surface has become urgent due to the serious effects of UV rays on human health, the environment and the biological evolution; therefore, the development of energy-saving UV photodetectors with high responsivity, specific detectivity, and sensitivity is urgently desired. Herein, we fabricated a lateral β-Ga2O3 Schottky photodiode on a sapphire substrate via magnetron sputtering using Ti and Ni as ohmic and Schottky contacts, respectively. The photodiode shows rectifying behaviors in the dark and under 254/365 nm UV light illuminations. As a photodetector, it exhibits the high photo-to-dark current ratio of 2.83 × 105 owing to its low dark current (1.32 × 10−11 A) and strong UV absorbance. The responsivity at 250 nm could reach up to 144.46 A W−1 at 10 V. The external quantum efficiency of 64 711% and the ideal specific detectivity of 7.29 × 1014 cm Hz1/2 W−1 (Jones) were also achieved. The rejection ratio (R250 nm/R400 nm) was as high as 4.8 × 103, suggesting high wavelength selectivity. The responsivity of 2301.78 A W−1 at 180 V proves the ability of this photodetector to operate at high voltages. In addition, it can operate with the responsivity of 0.73 mA W−1 and the specific detectivity of 3.35 × 1010 cm Hz1/2 W−1 (Jones) at zero bias. Overall, the lateral Ti/β-Ga2O3/Ni structured Schottky photodiode was verified as an excellent candidate for UV solar-blind detection with high performance and low energy consumption.
Article
Full-text available
In the recently published GRL paper by Seckmeyer et al. [1996] an example of a cloud that has a wavelength dependent effect on the surface UV-radiation is given. Through careful and accurate radiative transfer modelling, the present paper aims to give a physical interpretation of the reported wavelength dependence of this particular cloud. The modelling shows that the transmission of the cloud alone does not vary significantly with wavelength in the UV. However, the cloud gives a wavelength dependent effect in the surface UV-radiation due to radiation scattered upwards from the cloud and then scattered downwards again, effectively trying to make it through the cloud more than once. The number of photons this happens to is a function of the wavelength dependent Rayleigh scattering and ozone absorption cross sections.
Article
Full-text available
Approximately 10,000 UV irradiance spectra resulting from 2 years of continuous measurements in Germany were used as a database to analyze the effect of cloudiness on spectral UV irradiance. Values of spectral cloud modification factors (CMF) were derived by modeling a corresponding clear-sky irradiance spectrum for every UV measurement under cloudy conditions. The total set of CMF values was used to train neural networks using different sets of input data (parameter records) to describe the clouds, resulting in different, optimized, algorithms (CMF parameterizations). These different CMF parameterizations were evaluated by asking how the quality of the derived CMFs depended on the information content of different parameter records. It was shown that a visual description of cloudiness is not adequate to determine CMFs for an actual case (deviations of 50% and more), even if it was known whether or not the solar disk was obscured by clouds. Improvements for the determination of actual CMFs are possible, with deviations mostly below 15% if the parameter record comprises an actual broadband irradiance measurement. It was shown that such a CMF parameterization is able to provide a good estimation of actual CMFs, also for places with a different cloud climatology. The sensitivity of CMFs to wavelength and solar zenith angle was investigated on the basis of the derived CMF parameterizations. The relations found depend on the kind of CMF parameterization, i.e., the parameter record. In particular the separation of those cases when the solar disk is visible from those cases when the solar disk is obscured may lead to different dependencies of CMFs on solar zenith angle and wavelength.
Article
Full-text available
Narrowband ultraviolet B (NB-UVB) induces different immunological features from broadband ultraviolet B and is effective for the treatment of various cutaneous diseases. UV exposure alters the morphology and function of epidermal Langerhans cells (LCs), which can elicit cutaneous immunosuppressive responses. Recent studies have proposed that LCs serve as immunoregulatory cells in UV-induced immune suppression. This study investigated the cellular mechanisms of NB-UVB-induced immune suppression, including its effects on LC migration. NB-UVB irradiation induced the migration of epidermal LCs from the skin to the draining lymph nodes in a time- and dose-dependent manner. Experiments in Lang-DTR knock-in mice confirmed that epidermal LCs rather than Langerin+ dermal dendritic cells are essential for NB-UVB-induced immune suppression. These findings indicate that LCs play a critical immunoregulatory role in NB-UVB-induced immune suppression and NB-UVB phototherapy.
Article
Full-text available
By means of a simple mathematical model recently developed by the authors (2010 Phys. Educ. 45 641), the passage of the seasons on the Earth is simulated for arbitrary latitudes, taking into account sunlight attenuation in the atmosphere. The method developed can be used to predict a realistic value of the solar energy input (insolation) that can be absorbed by horizontal ground at sea level on any cloudless day of year. Some ideas for estimating daily insolation on to horizontal ground using the duration of daylight and the length of a shadow at the solar noon are discussed.
Article
Full-text available
Epidemiology shows a relationship between solar exposure and all types of skin cancer. Understanding the mechanisms of skin cancer requires knowledge of the photomolecular events that occur within the relevant epidermal cell types in vivo. Studies to date have focused on UVR-induced DNA lesions in keratinocytes, the majority epidermal cell population which gives rise to most skin cancers. Malignant melanoma, arising from melanocytes (5%–10% of epidermal cells), accounts for most skin cancer deaths. We report on new techniques to detect DNA photolesions in human epidermal melanocytes in situ. Previously nonexposed buttock skin of volunteers of skin types I/II was exposed to clinically relevant doses of narrow bandwidth UVB (300 nm) and UVA (320 nm, 340 nm, 360 nm) radiation. Biopsies were taken immediately afterwards and processed for routine histology. Microscope sections were prepared and double-stained with fluorescent-tagged monoclonal antibodies for thymine dimers and melanocytes. UVR dose–response curves for dimer levels within melanocyte nuclei were determined by image analysis and compared with dimer levels in adjacent basal cell keratinocytes. Our data show that UVB and UVA readily induce thymine dimers in melanocytes at levels that are comparable with those found in adjacent keratinocytes. This new technique will enable melanocyte specific studies, such as DNA repair kinetics, to be done in vivo.Keywords: image analysis
Article
Full-text available
The Montreal Protocol is working, but it will take several decades for ozone to return to 1980 levels. The atmospheric concentrations of ozone depleting substances are decreasing, and ozone column amounts are no longer decreasing. Mid-latitude ozone is expected to return to 1980 levels before mid-century, slightly earlier than predicted previously. However, the recovery rate will be slower at high latitudes. Springtime ozone depletion is expected to continue to occur at polar latitudes, especially in Antarctica, in the next few decades. Because of the success of the Protocol, increases in UV-B radiation have been small outside regions affected by the Antarctic ozone hole, and have been difficult to detect. There is a large variability in UV-B radiation due to factors other than ozone, such as clouds and aerosols. There are few long-term measurements available to confirm the increases that would have occurred as a result of ozone depletion. At mid-latitudes UV-B irradiances are currently only slightly greater than in 1980 (increases less than ~5%), but increases have been substantial at high and polar latitudes where ozone depletion has been larger. Without the Montreal Protocol, peak values of sunburning UV radiation could have been tripled by 2065 at mid-northern latitudes. This would have had serious consequences for the environment and for human health. There are strong interactions between ozone depletion and changes in climate induced by increasing greenhouse gases (GHGs). Ozone depletion affects climate, and climate change affects ozone. The successful implementation of the Montreal Protocol has had a marked effect on climate change. The calculated reduction in radiative forcing due to the phase-out of chlorofluorocarbons (CFCs) far exceeds that from the measures taken under the Kyoto protocol for the reduction of GHGs. Thus the phase-out of CFCs is currently tending to counteract the increases in surface temperature due to increased GHGs. The amount of stratospheric ozone can also be affected by the increases in the concentration of GHGs, which lead to decreased temperatures in the stratosphere and accelerated circulation patterns. These changes tend to decrease total ozone in the tropics and increase total ozone at mid and high latitudes. Changes in circulation induced by changes in ozone can also affect patterns of surface wind and rainfall. The projected changes in ozone and clouds may lead to large decreases in UV at high latitudes, where UV is already low; and to small increases at low latitudes, where it is already high. This could have important implications for health and ecosystems. Compared to 1980, UV-B irradiance towards the end of the 21st century is projected to be lower at mid to high latitudes by between 5 and 20% respectively, and higher by 2-3% in the low latitudes. However, these projections must be treated with caution because they also depend strongly on changes in cloud cover, air pollutants, and aerosols, all of which are influenced by climate change, and their future is uncertain. Strong interactions between ozone depletion and climate change and uncertainties in the measurements and models limit our confidence in predicting the future UV radiation. It is therefore important to improve our understanding of the processes involved, and to continue monitoring ozone and surface UV spectral irradiances both from the surface and from satellites so we can respond to unexpected changes in the future.
Article
Full-text available
Indoor tanning has been only weakly associated with melanoma risk; most reports were unable to adjust for sun exposure, confirm a dose-response, or examine specific tanning devices. A population-based case-control study was conducted to address these limitations. Cases of invasive cutaneous melanoma, diagnosed in Minnesota between 2004 and 2007 at ages 25 to 59, were ascertained from a statewide cancer registry; age-matched and gender-matched controls were randomly selected from state driver's license lists. Self-administered questionnaires and telephone interviews included information on ever use of indoor tanning, types of device used, initiation age, period of use, dose, duration, and indoor tanning-related burns. Odds ratios (OR) and 95% confidence intervals (CI) were adjusted for known melanoma risk factors. Among 1,167 cases and 1,101 controls, 62.9% of cases and 51.1% of controls had tanned indoors (adjusted OR 1.74; 95% CI, 1.42-2.14). Melanoma risk was pronounced among users of UVB-enhanced (adjusted OR, 2.86; 95% CI, 2.03-4.03) and primarily UVA-emitting devices (adjusted OR, 4.44; 95% CI, 2.45-8.02). Risk increased with use: years (P < 0.006), hours (P < 0.0001), or sessions (P = 0.0002). ORs were elevated within each initiation age category; among indoor tanners, years used was more relevant for melanoma development. In a highly exposed population, frequent indoor tanning increased melanoma risk, regardless of age when indoor tanning began. Elevated risks were observed across devices. This study overcomes some of the limitations of earlier reports and provides strong support for the recent declaration by the IARC that tanning devices are carcinogenic in humans.
Article
Full-text available
The parties to the Montreal Protocol are informed by three panels of experts. One of these is the Environmental Effects Assessment Panel (EEAP), which deals with UV radiation and its effects on human health, animals, plants, biogeochemistry, air quality and materials. Since 2000, the analyses and interpretation of these effects have included interactions between UV radiation and global climate change. When considering the effects of climate change, it has become clear that processes resulting in changes in stratospheric ozone are more complex than believed previously. As a result of this, human health and environmental problems will likely be longer-lasting and more regionally variable. Like the other panels, the EEAP produces a detailed report every four years; the most recent was that for 2006 (Photochem. Photobiol. Sci., 2007, 6, 201-332). In the years in between, the EEAP produces a less detailed and shorter progress report, as is the case for this present one for 2009. A full quadrennial report will follow for 2010.
Article
Full-text available
Spectral measurements of UV irradiances at Tokyo are compared with corresponding measurements at a pristine site (Lauder New Zealand) to identify the causes of the reductions in urban UV irradiances, and to quantify their effects. Tropospheric extinctions in Tokyo were found to be up to ~40% greater than at Lauder. Most of these differences can be explained by differences in cloud and aerosols, but ozone differences are also important in the summer. Examining spectral signatures of tropospheric transmission of both sites shows that reductions due to mean NO<sub>2</sub> and SO<sub>2</sub> amounts are generally small. However, at times the amount of NO<sub>2</sub> can be 20 times higher than the mean amount, and on these days it can decrease the UV-A irradiance up to 50%. If SO<sub>2</sub> shows comparable day to day variability, it would contribute to significant reductions in UV-B irradiances. The results indicate that at Tokyo, interactions between the larger burden of tropospheric ozone and aerosols also have a significant effect. These results have important implications for our ability to accurately retrieve surface UV irradiances at polluted sites from satellites that use backscattered UV. Supplementary data characterising these boundary layer effects are probably needed.
Article
In 1925, I published an article¹ on the treatment for psoriasis by an ointment of crude coal tar and ultraviolet light. This treatment has given far better results than any method I have ever used. The advantages that I claimed for this treatment were its uniform effectiveness, its lack of danger and even untoward symptoms, its nondestructive character, its accessibility and its comparative cheapness. Further experience justifies these claims, and in some respects establishes the method as being unique in its therapeutic results. DEVELOPMENT OF THE METHOD OF TREATMENT It has long been known that most patients with psoriasis are better in summer than in winter, that a sojourn in a locality with much sunshine is beneficial, and that sunbaths alone will clear up some attacks. Therefore, it was argued that if it were possible to sensitize the patches artificially, the response to light should be more
Article
The acute and chronic consequences of ultraviolet radiation on human skin are reviewed. An awareness of variations in naturally occurring photoprotective agents and the use of glass, sunglasses, and fabric can lead to effective protection from the deleterious effects of ultraviolet radiation. New systemic agents, including Polypodium leucotomos, afamelanotide, and antioxidants have potential as photoprotective agents.
Article
Spectral irradiance measured at two stations at different altitudes (the Zugspitze-summit at 2964 m a.s.l. and the Fraunhofer-Institute for Atmospheric Environmental Research at 730 m a.s.l., 8 km apart in horizontal direction) was used to examine the spectral attenuation of the UV-irradiance by a homogenous cloud-layer at an altitude of about 1200 m. Calculating the ratio of the global spectral irradiance beneath a homogenous cloud-cover (22 October, 1995) to the global spectral irradiance on a cloudless day (24 October, 1995) both measured at the valley station, delivered the spectral transmittance of the cloud. By means of data measured on the Zugspitze on the same two days possible differences in the atmospheric conditions above 2964 m were eliminated and thus the influence of the cloud on the UV-irradiance at Garmisch-Partenkirchen was separated. The transmittance of the cloud-layer was found to be wavelength-dependent, ranging from 45% in the UVA to 60% in the UVB. Therefore it can be assumed that clouds are not generally ``grey'' (i.e. that the attenuation is dependent on wavelength).
Article
— The levels of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) in purified calf thymus DNA and HeLa cells were measured following exposure to either UVC, UVB or UVA wavelengths. This DNA damage was quantitated using HPLC coupled with an electrochemical detector. The 8-oxodGuo was induced in purified DNA in a linear dose-dependent fashion by each portion of the UV spectrum at yields of 100, 0.46 and 0.16 8-oxodGuo per 105 2'-deoxyguanosine (dGuo) per kJ/m2 for UVC, UVB and UVA, respectively. However, the amount of 8-oxodGuo in HeLa cells irradiated with these UV sources decreased to approximately 2.0, 0.013 and 0.0034 8-oxodGuo per 105 dGuo per kJ/m2, respectively. In contrast, the levels of cyclobutyl pyrimidine dimers were similar in both irradiated DNA and cells. Therefore, 8-oxodGuo is induced in cells exposed to wavelengths throughout the UV spectrum although it appears that protective precesses exist within cells that reduce the UV-induced formation of this oxidative DNA damage. Cell survival was also measured and the number of dimers or 8-oxodGuo per genome per lethal event determined. These calculations are consistent with the conclusion that dimers play a major role in cell lethality for UVC- or UVB-irradiated cells but only a minor role in cells exposed to UVA wavelengths. In addition, it was found that the relative yield of 8-oxodGuo to dimers increased nearly 1000-fold in both UVA-irra-diated cells and DNA compared with cells subjected to either UVC or UVB. These results are supportive of the hypothesis that 8-oxodGuo, and possible other forms of oxidative damage, play an important role in the induction of biological effects caused by wavelengths in the UVA portion of the solar spectrum.
Article
Sun exposure of the skin triggers several inflammatory pathways via a multitude of photochemical and photobiological effects. Furthermore, local and systemic immune suppression develops. The main clinical effects of UV exposure can be classified schematically into immediate, including sunburn, tanning, vitamin D production and exacerbation of inherited and acquired photosensitive skin disorders and long-term, including solar ageing and skin cancer. The protection against solar radiation is afforded by a healthy behavior of reasonable sun avoidance and the use of topical sunscreens as well as topical and oral antioxidants. However, users of sunscreen products should be able to choose correctly the more convenient product according to their needs. In Europe, the sun protection factor (SPF) and the UVA-protection factor (UVA-PF) are labeled to indicate the degree of protection against UVB and UVA, respectively. However, dermatologists must be aware that the present knowledge of UV effects on human skin needs to be clarified and several regulatory issues of photo-protection remain to be clarified and standardized. Finally, much work is needed to improve water resistance, spreadability, transparency and homogeneity of the sunscreen agents.
Article
Oral 8-methoxypsoralen-UV-A (PUVA) and narrowband UV-B (NB-UVB or UVB TL-01) are effective and widely used treatments for chronic plaque psoriasis. Although the role of PUVA therapy in skin carcinogenesis in humans with psoriasis has been clearly demonstrated, there is still controversy regarding the risk of skin cancer with NB-UVB. Furthermore, there is no clear evidence about the maximum cumulative number of sessions not to be exceeded in a lifetime. To assess the respective cutaneous carcinogenic risks of PUVA or NB-UVB in psoriasis; to estimate the respective dose-relationship between skin cancers and PUVA or NB-UVB; to estimate a maximum number of sessions for PUVA or NB-UVB not to be exceeded in a lifetime. A systematic literature search was carried out in Medline, Embase and Cochrane Library databases from1980 to December 2010 in English and French, with the keywords 'Psoriasis' AND 'UVB therapy' AND 'UVA therapy' AND 'cancer' AND 'skin' OR 'neoplasm' OR 'cutaneous carcinoma' OR 'melanoma'. Of 243 identified references, 49 published studies were included. Most of them (45/49) concerned PUVA therapy, with 41 assessing the risk of non-melanoma skin cancers (NMSC) following PUVA. All publications referring to the US prospective PUVA follow-up study revealed an increased risk of NMSC with the following characteristics: risk most pronounced for squamous cell carcinomas developing even with low exposures and increasing linearly with the number of sessions, tumors occurring also on non-exposed skin including invasive penile tumors, risk persisting after cessation of treatment. An increased risk of basal cell carcinomas was observed in patients receiving more than hundred PUVA sessions. The four prospective European studies selected in our review and most of the pre-1990 European and US retrospective studies failed to find a link between exposure to PUVA and skin cancer. Only the most recent cohorts, including three large long-term retrospective European studies comparing records with their respective national cancer registries reported on an independent increased risk of NMSC with PUVA, The risk was lower as compared to the US prospective PUVA follow-up study. Six studies assessed the risk of melanoma following PUVA therapy: two of the three US publications coming from the same PUVA prospective follow-up study revealed an increased risk with more than doubled incidence of both invasive and in situ melanoma among patients exposed to at least 200 PUVA treatments compared with patients exposed to lower doses, whereas the three retrospectives European studies, comparing the incidence of melanoma in PUVA users with national cancer registers, did not find any increased risk of melanoma. No increased risk of skin cancer was evidenced in the four studies specifically assessing the potential carcinogenic risk of NB-UVB. There is an increased risk of skin cancer following PUVA, shown by both US and European studies. The greater risk measured by the US studies may be at least partly explained by high UVA dose exposure and the lighter phototypes of the treated patients. The lack of prospective studies in psoriasis patients treated with NB-UVB constitutes a barrier to the robust assessment of carcinogenic risk of this phototherapy technique.
Article
Total cumulative sun exposure is associated with the development of squamous cell and basal cell cancers, whereas intense intermittent sun exposure is associated with the development of melanoma. Exposure to UV radiation is the only known modifiable cause of melanoma, but the role of sunscreen in melanoma prevention remains somewhat controversial. This article discusses how UV radiation contributes to the pathogenesis of melanoma, how sunscreen modulates the action of UV radiation on the skin, and the effect of sunscreen on the risk of developing melanoma. A review of available sunscreen agents and their sun-protective properties is also included.
Article
Fifty two psoriatic patients were treated with a new experimental fluorescent lamp (Philips TL-01) emitting a narrow band at 311 ± 2 nm (UVB) which had the advantage of a reduction in burning and carcinogenic wavelengths when compared with conventional broad band UVB therapy. Results of the ‘311’ treated group when compared with broad band UVB therapy revealed a similar percentage of patients achieving a satisfactory response with fewer burning episodes and an increase in duration of remission.
Article
Since the first assessments in 1989, the complexity of the linkages between ozone depletion, UV-B radiation and climate change has become more apparent. This makes it even clearer than before that we are dealing with long-term developments, which can be complicated by large year-to-year variability.
Article
Free radicals have long been studied as a contributor to aging and disease processes. Endogenous production of radicals from cellular metabolism and exogenous sources from ultraviolet radiation and pollution can damage the skin on the cellular and tissue levels. Although the body possesses an elegant defense system to prevent radical damage, this innate system can be overwhelmed and lead to a state of oxidative stress or immunosuppression, and can even trigger carcinogenesis. Topical supplementation of antioxidants can provide additional protection to neutralize reactive oxygen species from both endogenous and exogenous sources. This review will discuss our current understanding of the mechanisms of free radical damage and evaluate the potential benefit of topical antioxidants in sunscreens and skin care products.
Article
Sunburns are an important risk factor for melanoma and those occurring in childhood are often cited as posing the greatest risk. We conducted a meta-analysis to quantify the magnitude of association for melanoma and sunburns during childhood, adolescence, adulthood and over a lifetime. After reviewing over 1300 article titles and evaluating 270 articles in detail, we pooled odds ratios from 51 independent study populations for "ever" sunburned and risk of cutaneous melanoma. Among these, 26 studies reported results from dose-response analyses. Dose-response analyses were examined using both fixed-effects models and Bayesian random-effects models. An increased risk of melanoma was seen with increasing number of sunburns for all time-periods (childhood, adolescence, adulthood, and lifetime). In an attempt to understand how risk between life-periods compares, we also report these same linear models on a scale of five sunburns per decade for each life-period. The magnitude of risk for five sunburns per decade is highest for adult and lifetime sunburns. Overall, these results show an increased risk of melanoma with increasing number of sunburns during all life-periods, not just childhood. Prevention efforts should focus on reducing sunburns during all life-periods.
Article
Based on the data of solar radiation and air pollutants collected in Beijing, the relationship between surface ultraviolet (UV) radiation and the content of air pollutants were analyzed, using the radiative transfer model TUV4.4 (Tropospheric Ultraviolet Visible). The results show that average total ozone content is 329 DU and higher in winter and spring, lower in summer and autumn. The inverse relationship exists between ground level UV radiation and total ozone content. This study also shows that a substantial reduction (up to 50%) in the UV radiation on days with high levels of air pollution. Larger fluctuations are found in UV radiation in the summer. The effects of clouds and air pollution on UV are higher than on total solar radiation, and the reduction in UV is about twice as large as the total solar radiation values. Strong reduction in the UV radiation reaching the ground is associated with the increase of tropospheric ozone and nitrogen oxides in Beijing. The correlation coefficient between ozone concentration and decrease in UV radiation is 0.70 in the early afternoon.
Article
Regular sunscreen use prevents cutaneous squamous cell carcinoma long term, but the effect on melanoma is highly controversial. We evaluated whether long-term application of sunscreen decreases risk of cutaneous melanoma. Participants and In 1992, 1,621 randomly selected residents of Nambour, a township in Queensland, Australia, age 25 to 75 years, were randomly assigned to daily or discretionary sunscreen application to head and arms in combination with 30 mg beta carotene or placebo supplements until 1996. Participants were observed until 2006 with questionnaires and/or through pathology laboratories and the cancer registry to ascertain primary melanoma occurrence. Ten years after trial cessation, 11 new primary melanomas had been identified in the daily sunscreen group, and 22 had been identified in the discretionary group, which represented a reduction of the observed rate in those randomly assigned to daily sunscreen use (hazard ratio [HR], 0.50; 95% CI, 0.24 to 1.02; P = .051). The reduction in invasive melanomas was substantial (n = 3 in active v 11 in control group; HR, 0.27; 95% CI, 0.08 to 0.97) compared with that for preinvasive melanomas (HR, 0.73; 95% CI, 0.29 to 1.81). Melanoma may be preventable by regular sunscreen use in adults.
Article
Skin cancer incidence is higher than that of any other human malignancy, and yet one of its root causes [ultraviolet (UV) radiation] is perhaps better understood than any other human carcinogen. The roles of UV radiation exposure and indoor tanning behaviors on skin cancer risk are explored here. Studies from the past several years have shown a significant association between ever-use of an indoor tanning facility and an increased risk of basal cell carcinoma, squamous cell carcinoma, and melanoma. The association between indoor tanning and skin cancer is particularly strong among those who first used a tanning facility in early adulthood. Elevated vitamin D levels have been suggested to protect against various internal malignancies and other disease states, but sources of vitamin D that do not require UV exposure are easily available. Although additional research is needed to understand fully the relationship between UV and skin cancer, it is already clear that indoor tanning bed use represents an avoidable risk factor for melanoma and nonmelanoma skin cancer - both of which may be lethal. Acting upon this information provides a unique opportunity for protecting the public health.
Article
Natural CD4(+)CD25(+) regulatory T cells (T(reg)) show a potent immunosuppressive function and contribute to immunologic self-tolerance by suppressing potentially auto-reactive T cells. Depletion of these cells leads to the induction of severe autoimmune diseases in animal models; more recently, several studies have also reported an impairment of T(reg) number and/or function in various human autoimmune diseases. For example, aberrant numbers of circulating CD4(+)CD25(+) T(reg) have been seen in patients with type I diabetes, mycosis fungoides, graft-versus-host-reaction, and rheumatoid arthritis. Moreover, increased numbers of functionally active CD4(+)CD25(+) T(reg) have been detected in the synovial fluid of patients with rheumatoid arthritis. In systemic lupus erythematosus (SLE), conflicting data on the role of CD4(+)CD25(+) T(reg) in human autoimmune diseases have been presented in the literature. Decreased numbers of peripheral blood T(reg) have been reported by most studies on SLE patients with active disease, but non-impaired or even increased CD4(+)CD25(+) T(reg) numbers have also been described. In addition, both deficient and normal suppressive capacity of isolated T(reg) have been observed in SLE. Analysis of CD4(+)FoxP3(+) T(reg) in skin lesions of patients with a primarily cutaneous manifestation of the disease showed a significant reduction in cell numbers as compared to other inflammatory skin diseases, suggesting the importance of analyzing T(reg) numbers in the affected tissue. In this review, we discuss the role of CD4(+)CD25(+) T(reg) in autoimmunity and recent published data on SLE. Furthermore, we highlight the need for additional studies that address specific gaps of knowledge regarding the pathophysiological mechanisms as well as the identification of future therapeutic strategies for autoimmune diseases.
Article
The FDA recently published a proposed amendment of the Final Monograph for OTC Sunscreen Products. Among the proposals, FDA revised solar simulator performance specifications and additional labeling for sunscreen products. The maximum allowable labeled sun protection factor (SPF) was increased to SPF 50 while simultaneously requiring it to be called 'UVB-SPF'. UVB accounts for 80-91% of the erythemic effectiveness of the UV solar simulator specified in the amendment. Analysis of the specified solar simulator spectrum used to determine SPF indicates that if 100% of the UVB is blocked, it is mathematically impossible to achieve an SPF in excess of approximately 11 without also blocking at least some UVA. Consequently significant UVA protection must be provided for sunscreen products to achieve SPFs of 15 and higher. At the maximum allowed SPF 50, where only 2% or less of the effective UV risk remains, the minimum reduction of UVA erythemal effectiveness must by definition be 78-90%. While mandating UVA protection criteria is doubtless important, especially as it relates to sunscreen photostability, there is no utility in, or basis for, the proposed 'UVB-SPF' descriptor as existing high SPF labeling indicates both UVB and UVA protection.
Article
Guidelines for submitting commentsPolicy: Comments that contribute to the discussion of the article will be posted within approximately three business days. We do not accept anonymous comments. Please include your email address; the address will not be displayed in the posted comment. Cell Press Editors will screen the comments to ensure that they are relevant and appropriate but comments will not be edited. The ultimate decision on publication of an online comment is at the Editors' discretion. Formatting: Please include a title for the comment and your affiliation. Note that symbols (e.g. Greek letters) may not transmit properly in this form due to potential software compatibility issues. Please spell out the words in place of the symbols (e.g. replace “α” with “alpha”). Comments should be no more than 8,000 characters (including spaces ) in length. References may be included when necessary but should be kept to a minimum. Be careful if copying and pasting from a Word document. Smart quotes can cause problems in the form. If you experience difficulties, please convert to a plain text file and then copy and paste into the form.
Article
Genomic DNA from 14 basal cell carcinoma biopsies was screened for the presence of mutations in the p53 gene, using the polymerase chain reaction followed by direct DNA sequencing. Heterozygous mutations were detected in 7 of 14 (50%) samples investigated. All mutations were G:C-A:T transitions, and five (71%) of these mutations were transitions at hot spots with CpG sites, three at codon 248 and two at codon 273. The striking similarity of the type of mutations detected in this study and with the UV mutagenesis studies reported in literature suggest the hypothesis that UV may act on the p53 gene in a carcinogenic-specific fashion.
Article
Activation of the p'ili tumor suppressor protein has boon demonst rated to block cell growth by inducing oit hoi a transient cell cycle arrest, or bv imlm ing, programmed roll death (apoptosis). Although evidence exists linking t ho transation function of p53 with its anolity to effect cell cycle arrest. ret eut data indicate that this activity may be in part d U p m sa bio for t lie ability of this protein to induce apoptosis. Recent studies from this laboratory ami oth ors point to the transcriptionsl repression function of p5ii as being influential in p53-mediated apoptosis. Two lines of evidence supporting this hypothesis will be presented: first, a mutant of human p53 has been constructed, in which the prolinf-rich region iron) residues 61 to 94 has boon deleted. In vilo. this mutant has transactivation capabilities that are indistinguishable fiom the wild lype protein, but this mutant is compromised in its ability to induce apoptosis; additionally, thi- mutant is also severely attenuated in its ability to function as a transcriptiotial repressor. Second, we have tested the hypothesis that pM can function as a sequence-specific trauscriptional repressor; several candidate p53-repressed genes have been isolated, all of which demonstrate reduced trariscriptional initiation following physiological induction of wt p53. Importantly. overoxpresMon of one of these genes, the microtubule associated protein MAP', can delay p53-dependent apoplosis, 'I hese data support the hypothesis thai t he tranM riptional repression function of poll is "mi port,m t lor the ability of this protein to effect . ipoptosis.
Article
The cell cycle is composed of a series of steps which can be negatively or positively regulated by various factors. Chief among the negative regulators is the p53 protein. Alteration or inactivation of p53 by mutation, or by its interactions with oncogene products of DNA tumour viruses, can lead to cancer. These mutations seem to be the most common genetic change in human cancers.
Article
UV radiation is a potent DNA damaging agent and a known inducer of skin cancer in experimental animals. There is excellent scientific evidence to indicate that most non-melanoma human skin cancers are induced by repeated exposure to sunlight. UV radiation is unique in that it induces DNA damage that differs from the lesions induced by any other carcinogen. The prevalence of skin cancer on sun-exposed body sites in individuals with the inherited disorder XP suggests that defective repair of UV-induced DNA damage can lead to cancer induction. Carcinogenesis in the skin, as elsewhere, is a multistep process in which a series of genetic and epigenetic events leads to the emergence of a clone of cells that have escaped normal growth control mechanisms. The principal candidates that are involved in these events are oncogenes and tumor suppressor genes. Oncogenes display a positive effect on transformation, whereas tumor suppressor genes have an essentially negative effect, blocking transformation. Activated ras oncogenes have been identified in human skin cancers. In most cases, the mutations in the ras oncogenes have been localized to pyrimidine-rich sequences, which indicates that these sites are probably the targets for UV-induced DNA damage and subsequent mutation and transformation. The finding that activation of ras oncogenes in benign and self-regressing keratoacanthomas in both humans and in animals indicates that they play a role in the early stages of carcinogenesis (Corominas et al., 1989; Kumar et al., 1990). Since cancers do not arise immediately after exposure to physical or chemical carcinogens, ras oncogenes must remain latent for long periods of time. Tumor growth and progression into the more malignant stages may require additional events involving activation of other oncogenes or deletion of growth suppressor genes. In addition, amplification of proto-oncogenes or other genes may also be involved in tumor induction or progression. In contrast to the few studies that implicate the involvement of oncogenes in UV carcinogenesis, the role of tumor suppressor genes in UV carcinogenesis is unknown. Since cancer-prone individuals, particularly XP patients, lack one or more repair pathways, one can speculate that DNA repair enzymes would confer susceptibility to both spontaneous and environmentally induced cancers. Another potential candidate that can function as a tumor suppressor gene is the normal c-Ha-ras gene. Spandidos and Wilkie (1988) have shown that the normal c-Ha-ras gene can suppress transformation induced by the mutated ras gene.(ABSTRACT TRUNCATED AT 400 WORDS)
Article
Activated ras oncogenes have been detected in a variety of human malignancies. Activation of ras oncogenes usually occurs by point mutations within specific codons of the H-ras, N-ras, and K-ras genes. For the present study, DNA was isolated from 30 basal cell carcinomas (BCC) and 12 squamous cell carcinomas (SCC). After amplification of genomic DNA by using the polymerase chain reaction, the occurrence of point mutations was investigated with 32P-labeled synthetic oligonucleotides. These probes are complementary to the known point-mutated nucleotide sequences of the ras genes. In four out of the 30 BCC studied, point mutations were detected at codon 12 of the K-ras gene and at codon 61 of the H-ras gene. The K-ras mutations involve glycine to cysteine and glycine to asparagine amino acid changes. The mutation at codon 61 of the H-ras gene is consistent with a replacement of glutamine by histidine. In one SCC, a point mutation was detected at codon 12 of the K-ras gene, involving a glycine to cysteine substitution in the gene product. These findings demonstrate that mutational activation of ras genes takes place in skin carcinomas, but the rate at which these mutations occur seems to be relatively low.
Article
Fifty two psoriatic patients were treated with a new experimental fluorescent lamp (Philips TL-01) emitting a narrow band at 311 +/- 2 nm (UVB) which had the advantage of a reduction in burning and carcinogenic wavelengths when compared with conventional broad band UVB therapy. Results of the '311' treated group when compared with broad band UVB therapy revealed a similar percentage of patients achieving a satisfactory response with fewer burning episodes and an increase in duration of remission.