Deleterious Effects Of Ultraviolet Radiation Research Articles

Tolerance to UV-B radiation of the entomopathogenic fungus Metarhizium rileyi

Soybean, corn, and cotton crops are afflicted by several noctuid pests and the development of bioinsecticides could help control these pests. The fungus Metarhizium rileyi has the greatest potential because its epizootics decimate caterpillar populations in the absence of insecticide applications. However, insect-pathogenic fungi when used for insect control in agriculture have low survival mainly due to the deleterious effects of ultraviolet radiation and heat from solar radiation. In this study, fourteen isolates of M. rileyi were studied and compared with isolates ARSEF 324 and ARSEF 2575 of Metarhizium acridum and Metarhizium robertsii, respectively, whose sensitivity to UV-B radiation had previously been studied. Conidia were exposed at room temperature (ca. 26 °C) to 847.90 mWm−2 of Quaite-weighted UV-B using two fluorescent lamps. The plates containing the conidial suspensions were irradiated for 1, 2, and 3 h, providing doses of 3.05, 6.10, and 9.16 kJ m2, respectively. A wide variability in conidial UV-B tolerance was found among the fourteen isolates of M. rileyi. Isolate CNPSo-Mr 150 was the most tolerant isolate (germination above 80% after 2 h exposure), which was comparable to ARSEF 324 (germination above 90% after 2 h exposure), the most tolerant Metarhizium species. The least tolerant isolates were CNPSo-Mr 141, CNPSo-Mr 142, CNPSo-Mr 156, and CNPSo-Mr 597. Nine M. rileyi isolates exhibited similar tolerance to UV-B radiation as ARSEF 2575 (germination above 50% after 2 h exposure). In conclusion, the majority of M. rileyi isolates studied can endure 1 or 2 h of UV-B radiation exposure. However, after 3 h of exposure, the germination of all studied isolates reduced below 40%, except for CNPSo-Mr 150 and ARSEF 324.

A Scoping Review on the Effects of Carotenoids and Flavonoids on Skin Damage Due to Ultraviolet Radiation.

Skin exposure to ultraviolet (UV) rays in the sun causes premature ageing and may predispose to skin cancers. UV radiation generates excessive free radical species, resulting in oxidative stress, which is responsible for cellular and DNA damage. There is growing evidence that phytonutrients such as flavonoids and carotenoids may impede oxidative stress and prevent photodamage. We conducted a systematic review of the literature to explore the effects of certain phytonutrients in preventing skin photodamage. We searched the electronic Medline (Ovid) and Pubmed databases for relevant studies published between 2002 and 2022. The main inclusion criteria were articles written in English, and studies reporting the effects of phytonutrient-containing plants of interest on the skin or skin cells exposed to UV radiation. We focused on tea, blueberries, lemon, carrot, tomato, and grapes, which are rich in flavonoids and/or carotenoids. Out of 434 articles retrieved, 40 were identified as potentially relevant. Based on our inclusion criteria, nine articles were included in the review. The review comprises three combined in vitro and animal studies, four human studies, one in vitro research, and one mixed in vitro and human study. All the studies reported positive effects of flavonoids and carotenoid-containing plant extract on UV-induced skin damage. This evidence-based review highlights the potential use of flavonoids and carotenoids found in plants in preventing the deleterious effects of UV radiation on the skin. These compounds may have a role in clinical and aesthetic applications for the prevention and treatment of sunburn and photoaging, and may potentially be used against UV-related skin cancers.

Review on photoprotection: a clinician's guide to the ingredients, characteristics, adverse effects, and disease-specific benefits of chemical and physical sunscreen compounds.

Photoprotection is a critical health prevention strategy to reduce the deleterious effects of ultraviolet radiation (UVR) and visible light (VL). Methods of photoprotection are reviewed in this paper, with an emphasis on sunscreen. The most appropriate sunscreen formulation for personal use depends on several factors. Active sunscreen ingredients vary in their protective effect over the UVR and VL spectrum. There are dermatologic diseases that cause photosensitivity or that are aggravated by a particular action spectrum. In these situations, sunscreen suggestions can address the specific concern. Sunscreen does not represent a single entity. Appropriate personalized sunscreen selection is critical to improve compliance and clinical outcomes. Health care providers can facilitate informed product selection with awareness of evolving sunscreen formulations and counseling patients on appropriate use. This review aims to summarize different forms of photoprotection, discuss absorption of sunscreen ingredients, possible adverse effects, and disease-specific preferences for chemical, physical or oral agents that may decrease UVR and VL harmful effects.

Deleterious Effect of Ultraviolet Radiation on Glossogobius giuris: A Short Experimental Study

Ultraviolet (UV) radiation is a part of the spectrum of electromagnetic radiation emitted by the Sun. The present study was conducted to examine the deleterious effects of UV radiation on the stratum corneum of fish—namely, Glossogobius giuris. In this study, healthy living specimens of G. giuris species weighing (1.20 g) and length (4.06 cm) were collected from Thandavarayankulam lake, Srivaikuntam Taluk, Thoothukudi District, Tamil Nadu. They were transported to the laboratory in well-aerated containers. During the experiment, the fish G. giuris (n = 6) was introduced into the UV Chamber (UVA and UVB) for one hour. After that, experimental fishes were collected from the UV Chamber were dissected for histological and biochemical studies using standard methodology. The short-term exposure of UVA and UVB rays on freshwater G. giuris muscle tissue showed marked degeneration of the epithelium, the disappearance of striations, thickened septal wall, broken fibre, and the disappearance of striation, followed by branchial arterial rupture. It was also determined that carbohydrate, protein, and lipid contents of the muscle tissue were significantly reduced. This study confirmed the destructive effects of UV radiation on the stratum corneum of fish G. giuris. The ultrastructural and biochemical changes occur depending largely on the energy of the UV rays; in this case, the UVB radiation, with higher destructive energy (4.4 eV), had a greater detrimental effect on the muscles of G. giuris than UVA, with its energy level of 3.9 eV.

The Detectability Limit of Organic Molecules Within Mars South Polar Laboratory Analogs

AbstractA series of laboratory experiments was carried out in order to generate a diagnostic spectrum for polycyclic aromatic hydrocarbons (PAHs) of astrobiological interest in the context of the Martian South Polar Residual Cap (SPRC), to establish PAH spectral features more easily detectable in CO2 ice (mixed with small amounts of H2O ice) than the previously reported absorption feature at 3.29 µm in order to constrain their detectability limit. There is currently no existing literature on PAH detection within SPRC features, making this work novel and impactful given the recent discovery of a possible subglacial lake beneath the Martian South Pole. Although they have been detected in Martian meteorites, PAHs have not been detected yet on Mars, possibly due to the deleterious effects of ultraviolet radiation on the surface of the planet. SPRC features may provide protection to fragile molecules, and this work seeks to provide laboratory data to improve interpretation of orbital remote sensing spectroscopic imaging data. We also ascertain the effect of CO2 ice sublimation on organic spectra, as well as provide PAH reference spectra in mixtures relevant to Mars. A detectability limit of ∼0.04% has been recorded for observing PAHs in CO2 ice using laboratory instrument parameters emulating those of the Compact Reconnaissance Imaging Spectrometer for Mars, with new spectral slope features revealed between 0.7 and 1.1 µm, and absorption features at 1.14 and most sensitively, at 1.685 µm. Mars regolith analog mixed with a concentration of 1.5% PAHs resulted in no discernible organic spectral features. These detectability limits measured in the laboratory are discussed and extrapolated to the effective conditions on the Mars South Polar Cap in terms of dust and water ice abundance and CO2 ice grain size for both the main perennial cap and the H2O ice‐dust sublimation lag deposit.

The Modulating Effects of Sunscreen and Simulated Sweat on Ultraviolet Radiation‐ Induced Microvascular Dysfunction in the Human Cutaneous Vasculature

After acute ultraviolet radiation (UVR) exposure, nitric oxide (NO)‐mediated vasodilation is attenuated in the cutaneous microvasculature, likely via increased oxidative stress. Application of sunscreen to the skin protects from, while sweat on the skin may exacerbate, deleterious effects of UVR, including the erythema. However, it is unknown whether the presence of sunscreen or sweat on the skin influences the effect of UVR exposure on NO‐dependent vasodilation, a marker of skin vascular health.PurposeTo compare the impact of acute UVR, UVR with sunscreen (+SS), and UVR with simulated sweat (+SW) on NO‐mediated vasodilation in the cutaneous microcirculation. We hypothesized that +SS would blunt and +SW would augment the reduction in NO‐dependent vasodilation following acute UVR exposure.MethodsThree intradermal microdialysis fibers were placed in the ventral skin of the left forearm and a single fiber was placed in the right forearm of 13 healthy adults (24±1 yr; 6M/7F) with mild to moderate skin pigmentation (M‐index 30–46). Sites on the left forearm were randomly assigned to UVR exposure (450 mJ/cm2), UVR+SS (SPF‐50 chemical sunscreen), or UVR+SW (64 mmol Na+, 2.1 mmol K+), while the sight on the right forearm served as a non‐UVR exposed control (CON). Following UVR exposure, a standardized local heating (42°C) protocol induced cutaneous vasodilation. After attaining a plateau blood flow, 15mM NG‐nitro‐L‐arginine methyl ester (L‐NAME; NO synthase inhibitor) was infused at all sites to quantify the NO contribution to cutaneous vasodilation. Red cell flux was measured at each site (laser‐Doppler flowmetry) and cutaneous vascular conductance (CVC=flux/MAP) was expressed as a percentage of maximum (%CVCmax; 28mM sodium nitroprusside+43°C) for each phase of the local heating response. The NO‐mediated contribution (%NO) was calculated as the difference between the local heating and L‐NAME plateaus.ResultsThere were no differences in %CVCmax between treatments at baseline (p≥0.55), initial peak (p≥0.40), or heating plateau (p≥0.44). However, UVR blunted %NO compared to CON (CON: 40.8±4.8 vs UVR: 28.0±6.7%; p<0.01). The attenuation in %NO was prevented by sunscreen (UVR: 28.0±6.7 vs UVR+SS: 54.5±5.8%; p<0.01) and by simulated sweat (UVR: 28.0±6.7 vs UVR+SW: 45.8±5.2%; p<0.01). Further, when sunscreen was applied prior to UVR, UVR exposure actually augmented %NO compared to CON (UVR+SS: 54.5±5.8% vs CON: 40.8±4.8; p<0.01) or when sweat was on the skin (UVR+SS: 54.5±5.8 vs UVR+SW: 45.8±5.2%; p<0.01).ConclusionAcute broad spectrum UVR exposure attenuates NO‐mediated vasodilation in the cutaneous microvasculature. The presence of sunscreen or sweat on the skin may play a protective role against this effect, and UVR may actually augment NO‐mediated vasodilation in the presence of a chemical sunscreen.Support or Funding InformationACSM Foundation Doctoral Student Research Grant #17‐00552 and NIH T‐32 Grant #5T32AG049676‐03This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

The Effect of Ultraviolet Radiation and the Antioxidant Curcumin on the Longevity, Fertility, and Physical Structure of Drosophila melanogaster: Can We Defend Our DNA?

Ultraviolet (UV) radiation is known to alter DNA structure and impair cellular function in all living organisms. One proposed mechanism of injury involves the production of harmful free radicals. The DNA damage caused by UV radiation can lead to a myriad of medical issues, but there is limited research on potential rescue interventions. However, studies have suggested that naturally occurring antioxidants may exert their positive influence on an organism by reducing oxidative injury, which leads to the purpose of this project: to study the effects of UV radiation and determine whether antioxidant-enriched nutrition can combat the potential deleterious effects of UV radiation on Drosophila melanogaster. We hypothesized that UV radiation would diminish the lifespan and fertility of Drosophila, as well as causing physical abnormalities. We also predicted that Drosophila cultured in the presence of media enriched with the antioxidant curcumin would have enhanced lifespans and fertility. Finally, we hypothesized that raising Drosophila with curcumin-enriched media, would diminish the negative impact of UV radiation on the organism’s longevity and fertility. We found that UVB (320nm) radiation caused a 59% decrease in the Drosophila lifespan and mutagenic effects on flies' physical appearance, but did not significantly affect fertility. Curcumin significantly prolonged lifespan and enhanced fertility for both UV- and non-UV-exposed flies. Therefore, we conclude that curcumin can prolong lifespan, enhance fertility, and mitigate the deleterious effects of UV radiation on Drosophila. Our research demonstrates that we can harness the positive potential of natural antioxidants and use them as weapons in our war against radiation-induced diseases, including conditions like cancer.

The Xenon Test Chamber Q-SUN® for testing realistic tolerances of fungi exposed to simulated full spectrum solar radiation

The low survival of insect-pathogenic fungi when used for insect control in agriculture is mainly due to the deleterious effects of ultraviolet radiation and heat from solar irradiation. In this study, conidia of 15 species of entomopathogenic fungi were exposed to simulated full-spectrum solar radiation emitted by a Xenon Test Chamber Q-SUN XE-3-HC 340S (Q-LAB® Corporation, Westlake, OH, USA), which very closely simulates full-spectrum solar radiation. A dendrogram obtained from cluster analyses, based on lethal time 50 % and 90 % calculated by Probit analyses, separated the fungi into three clusters: cluster 3 contains species with highest tolerance to simulated full-spectrum solar radiation, included Metarhizium acridum, Cladosporium herbarum, and Trichothecium roseum with LT50 > 200 min irradiation. Cluster 2 contains eight species with moderate UV tolerance: Aschersonia aleyrodis, Isaria fumosorosea, Mariannaea pruinosa, Metarhizium anisopliae, Metarhizium brunneum, Metarhizium robertsii, Simplicillium lanosoniveum, and Torrubiella homopterorum with LT50 between 120 and 150 min irradiation. The four species in cluster 1 had the lowest UV tolerance: Lecanicillium aphanocladii, Beauveria bassiana, Tolypocladium cylindrosporum, and Tolypocladium inflatum with LT50 < 120 min irradiation. The QSUN Xenon Test Chamber XE3 is often used by the pharmaceutical and automotive industry to test light stability and weathering, respectively, but it was never used to evaluate fungal tolerance to full-spectrum solar radiation before. We conclude that the equipment provided an excellent tool for testing realistic tolerances of fungi to full-spectrum solar radiation of microbial agents for insect biological control in agriculture.

Short-term and diurnal temperature changes alter the response of harmful algal blooms of Pseudo-nitzschia pungens to solar ultraviolet radiation

ABSTRACTIn this study, we explored the interactive effects of temperature and solar ultraviolet radiation (UVR) on the growth, pigment contents, photochemical efficiency and non-photochemical quenching (NPQ) of Pseudo-nitzschia pungens, which forms harmful algal blooms globally. Cells were first pre-acclimated to temperatures of 20°C, 25°C or 28°C for 10 days. They were then exposed to three different types of solar radiation for 60 min. We then measured the photochemical efficiency of the cells during the 60-min exposure and a 360-min recovery period under dim light (20 μmol photons m−2 s−1). In addition, we analysed the diural change in photochemical efficiency and NPQ over a 10-h period. We found that P. pungens that were exposed to higher temperatures in the short term (i.e. 20–25°C, 20–28°C and 25–28°C) or long term (i.e. 25–25°C and 28–28°C) exhibited lower levels of photoinhibition and faster recovery rates than samples exposed to a lower temperature (i.e. 20–20°C). This indicated that the deleterious effects of UVR can be minimised by both chronic and acute exposure to higher temperatures within the tolerated temperature range for P. pungens.

Low-steady-state metabolism induced by elevated CO2 increases resilience to UV radiation in the unicellular green-algae Dunaliella tertiolecta

Global change factors derived from anthropogenic activities such as increased CO2 and ultraviolet radiation (UVR) have direct impacts on the physiological responses of organisms in both terrestrial and aquatic ecosystems. We assessed in this work the mechanistic, physiological and molecular response of the unicellular chlorophyte Dunaliella tertiolecta exposed to combinatorial present (390 ppmv, LC) and future CO2 levels predicted for the year 2100 (900 ppmv, HC) and different UVR doses. Growth rates, cell esterase activity, reactive oxygen species accumulation (ROS), and 14C fixation decreased under HC compared to LC. The deleterious effects of UVR were attenuated in HC, except for decreased photosynthetic capacities. Transcriptome analysis showed different expression patterns depending on UVR and CO2 levels. PsbA, LhcII and eCA gene expression was downregulated at HC compared to LC. However, photolyase (PL) gene expression was upregulated at HC with respect LC in UVR. This suggests that HC (as opposed to LC) promoted a “low-metabolic steady state”, decreasing UVR exposure-activated repair by means of protein replacement. Only PL photoreactivation was active under HC. Our data add evidence on D. tertiolecta possibly becoming more resilient to UVR exposure under future CO2 regimes, and maybe other marine unicellular chlorophytes, warranting serious considerations on the consequent ecological implications.

Abstract 2811: Silver nanoparticles protect human keratinocytes from deleterious effects of ultraviolet radiation: Implications for skin cancer chemoprevention

Abstract Skin cancer is the most common form of cancer worldwide and its incidence has been increasing at an alarming rate in the United States. A solar ultraviolet (UV) radiation, particularly UVB, is the main etiological cause of skin carcinogenesis due to its DNA damaging ability. Therefore, multidisciplinary scientific research has placed specific emphasis on finding novel ways for skin cancer chemoprevention. Here, we provide first experimental evidence for chemopreventive efficacy of silver-nanoparticles (AgNPs) against UVB-induced DNA damage and apoptosis in immortalized human epidermal keratinocytes (HaCaT). AgNPs synthesized by chemical reduction method were characterized for their physicochemical properties. The nanoparticles were spherical (&amp;gt; 90%) in shape, in the size range of 20-50 nm, and had net negative surface charge with an average zeta potential of - 47.7 mV. AgNPs were largely non-toxic to HaCaT cells and their pretreatment protected them from UVB-induced apoptosis. Significant reduction in cyclobutane pyrimidine dimer (CPD) formation upon UVB exposure was also observed in AgNPs-pretreated HaCaT cells. In addition, AgNPs pre-treatment leads to G1 phase arrest of cell cycle in UVB-exposed HaCaT cells thus allowing sufficient time for CPDs repair. Moreover, enhanced AgNPs internalization and localization into cytoplasmic and nuclear compartments was observed by UVB irradiated HaCaT cells. Furthermore, AgNPs pretreatment altered the expression of various genes involved in cell-cycle, apoptosis and nucleotide-excision repair in UVB-irradiated HaCaT cells. Together, these findings clearly suggest the potential utility of AgNPs as novel chemopreventive agents against UVB-induced skin carcinogenesis. Citation Format: Sumit Arora, Nikhil Tyagi, Arun Bhardwaj, Lilia Rusu, Rohan Palanki, Ajay P. Singh, James E. Carter, Seema Singh. Silver nanoparticles protect human keratinocytes from deleterious effects of ultraviolet radiation: Implications for skin cancer chemoprevention. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 2811. doi:10.1158/1538-7445.AM2015-2811

An Overview of Ultraviolet B Radiation-Induced Skin Cancer Chemoprevention by Silibinin

Skin cancer incidences are rising worldwide, and one of the major causative factors is excessive exposure to solar ultraviolet radiation (UVR). Annually, ~5 million skin cancer patients are treated in United States, mostly with nonmelanoma skin cancer (NMSC), which is also frequent in other Western countries. As sunscreens do not provide adequate protection against deleterious effects of UVR, additional and alternative chemoprevention strategies are urgently needed to reduce skin cancer burden. Over the last couple of decades, extensive research has been conducted to understand the molecular basis of skin carcinogenesis, and to identifying novel agents which could be useful in the chemoprevention of skin cancer. In this regard, several natural non-toxic compounds have shown promising efficacy in preventing skin carcinogenesis at initiation, promotion and progression stages, and are considered important in better management of skin cancer. Consistent with this, we and others have studied and established the notable efficacy of natural flavonolignan silibinin against UVB-induced skin carcinogenesis. Extensive pre-clinical animal and cell culture studies report strong anti-inflammatory, anti-oxidant, DNA damage repair, immune-modulatory and anti-proliferative properties of silibinin. Molecular studies have identified that silibinin targets pleotropic signaling pathways including mitogenic, cell cycle, apoptosis, autophagy, p53, NF-κB, etc. Overall, the skin cancer chemopreventive potential of silibinin is well supported by comprehensive mechanistic studies, suggesting its greater use against UV-induced cellular damages and photocarcinogenesis.

Effects of ultraviolet radiation and nutrients on the structure-function of phytoplankton in a high mountain lake

The combined effect of high solar ultraviolet radiation (UVR) and nutrient supply in a phytoplankton community of a high mountain lake is analyzed in a in situ experiment for 6 days with 2 × 2 factorial design. Interactive UVR × nutrient effects on structural and functional variables (algal biomass, chlorophyll a (chl a), primary production (PP), maximal electron transport rate (ETR(max)), and alkaline phosphatase activity (APA)), as well as stoichiometric ones (sestonic N per cell and N:P ratio) were found. Under non-nutrient enriched conditions, no deleterious effects of UVR on structural variables, PP, photosynthetic efficiency and ETR(max) were observed, whereas only particulate and total APA were affected by UVR. However, percentage excreted organic carbon (%EOC), dissolved APA and sestonic C and P per cell increased under UVR, leading to a decrease in algal C:P and N:P ratios. After nutrient enrichment, chl a, total algal biomass and PP were negatively affected by UVR whereas %EOC, ETR(max) and internal C, P and N content increased. We suggest that the mechanism of algal acclimation to UVR in this high UVR flux ecosystem seems to be related to the increase of internal algal P-content mediated by physiological mechanisms to save P and by a stimulatory UVR effect on dissolved extracellular APA. The mechanism involved in the unmasking effect of UVR after nutrient-enrichment may be the result of a greater sensitivity to UVR-induced cell damage, making the negative UVR effects more evident.

Human skin pigmentation, migration and disease susceptibility

Human skin pigmentation evolved as a compromise between the conflicting physiological demands of protection against the deleterious effects of ultraviolet radiation (UVR) and photosynthesis of UVB-dependent vitamin D(3). Living under high UVR near the equator, ancestral Homo sapiens had skin rich in protective eumelanin. Dispersals outside of the tropics were associated with positive selection for depigmentation to maximize cutaneous biosynthesis of pre-vitamin D(3) under low and highly seasonal UVB conditions. In recent centuries, migrations and high-speed transportation have brought many people into UVR regimes different from those experienced by their ancestors and, accordingly, exposed them to new disease risks. These have been increased by urbanization and changes in diet and lifestyle. Three examples-nutritional rickets, multiple sclerosis (MS) and cutaneous malignant melanoma (CMM)-are chosen to illustrate the serious health effects of mismatches between skin pigmentation and UVR. The aetiology of MS in particular provides insight into complex and contingent interactions of genetic and environmental factors necessary to trigger lethal disease states. Low UVB levels and vitamin D deficiencies produced by changes in location and lifestyle pose some of the most serious disease risks of the twenty-first century.

Topical Delivery of Antioxidants

Reactive oxygen species (ROS) and free radicals have been implicated in a number of diseases and disorders, and the skin, for its localization, is exposed to a large number of environmental threats. Free radical scavengers and antioxidants have thus been proposed as protective or therapeutic agents against ROS-mediated injuries. Oral treatment with several antioxidants has been reported to provide skin protection against deleterious effects of ultraviolet radiation. Topical delivery of antioxidants has increasingly gained interest and development, especially by offering better targeting to the upper skin layer. However, the topical delivery of antioxidants for dermal action is a challenging research field since the molecules are, in general, susceptible to degradation. The search for a new delivery system that, simultaneously, preserves the antioxidant stability and enhances its deposition on the skin, opened a new chapter in drug delivery design. Nanocarriers have been successful in enhancing the clinical efficiency of several drugs. More recent approaches in modulating through the skin delivery led to the development of specialized nanoparticulated systems. The first part of this article presents a review of the potential of antioxidants as pharmacological agents in ROS related diseases, with a special focus on oxidative stress implicated skin pathologies: ROS formation and natural protection against ROS toxicity, ROS-mediated skin damage and skin protection by antioxidants. In the second part of this work, we present reported formulation strategies for dermal delivery of antioxidants focusing on the nanoparticulated systems developed in recent years.

Higher severity grade of erlotinib-induced rash is associated with lower skin phototype

Epidermal growth factor receptor inhibitors (EGFRIs) are associated with a characteristic papulopustular rash, an adverse event considered to be a class effect of these agents. Erlotinib, a small-molecule EGFRI, causes a papulopustular rash in 68-75% of patients. The limited reported data suggest that deleterious effects of ultraviolet radiation (UVR) may enhance the development of EGFRI-induced rash. Because the level of the biological pigment melanin correlates with increased protection against UVR, we hypothesized that lighter levels of skin pigmentation are associated with greater severity of rash. To characterize the relationship between skin phototype (SPT) and rash severity. A retrospective chart review was conducted of 40 patients on erlotinib. Skin sensitivity to UVR was categorized using the Fitzpatrick SPT classification scheme. Grading of rash was performed using the National Cancer Institute Common Terminology Criteria for Adverse Events (NCI-CTCAE), version 3. There was an inverse relationship between SPT and rash severity. Grade 0 was seen in the majority of patients with SPT V/VI, grade 1/2 in the majority of patients with SPT III/IV, and grade 3/4 rash in the majority of patients with SPT I/II (grade 0: 7% SPT I/II, 32% SPT III/IV and 50% SPT IV/V; grade 1/2: 33%, 63% and 50%, respectively; grade 3/4: 60%, 5% and 0%, respectively) (P < 0.01, Fisher exact test). Prevention and management of cutaneous side-effects from EGFR inhibitors is important to achieve maximum patient compliance and therapeutic benefit. The results of this study suggest that SPT may be an independent predictive factor for EGFRI-induced papulopustular rash, thus pre-therapy counselling and early intervention are important.

Fotoprotección en la infancia

Children are the population group who most need photo protection. They are very sensitive to the negative consequences of an excessive sun exposure, and they aren’t aware of the risk. Children have much more open air activity than adults, and the exposure to ultraviolet radiation and sun burns in childhood are a risk factor of the utmost importance in the development of skin cancer in adulthood. It is therefore of vital relevance to protect the child from the deleterious effects of ultraviolet radiation. The photo protection measures include sun avoidance, protection with cloths, caps and solar glasses, and the use of photo protection ointments. Sun education campaigns should be implemented in hospitals, schools and communication media, and with dermatologists, pediatricians, teachers and political referents altogether.

Polypodium leucotomos extract inhibits glutathione oxidation and prevents Langerhans cell depletion induced by UVB/UVA radiation in a hairless rat model

In this report, we have addressed the effect of oral administration of a hydrophilic extract of the fern Polypodium leucotomos (PL) on the deleterious effects of ultraviolet radiation (UVR) on the levels of epidermal and plasmatic antioxidants in hairless rats. We have found that pretreatment with PL effectively reduced glutathione oxidation in both blood and epidermis, suggesting a potent systemic antioxidant effect. In addition, PL inhibited UVR-mediated Langerhans cell (LC) depletion. Our results demonstrate the efficacy of PL as an oral antioxidant and photoimmunoprotective agent and support its employment as a complement to topical sunscreens.

Practical and experimental consideration of sun protection in dermatology.

Much is known regarding the deleterious effects of ultraviolet radiation (UV) on the skin. As more epidemiologic and basic research continues to characterize the impact of sun exposure and other sources of UV radiation upon the development of cutaneous neoplasm and a variety of photosensitive dermatoses, it is crucial for the dermatologist to promote sun protection among his/her patients as well as the primary care physician who has a greater reach of the community than the skin specialist. Practical steps to achieve optimal sun protection include avoidance of UV radiation, avoidance of photosensitizing drugs, use of photo-protective clothing, and diligent application of broad-spectrum sunscreens. In recent years, novel agents and experimental modalities with the potential to offer enhanced protective effects against deleterious sequelae of sun exposure have been elucidated, e.g. antioxidants, alpha-MSH, polyphenol in green teas, genistein, NF-kB decoy oligodeoxynucleotides, pTpT vaccination, and IL-12. As these new photo-protective tools are being developed by scientists around the world, greater concerted effort is needed to engage public health officials and the media to promote sun protection awareness throughout the general public.

A questionnaire survey of attitudes to and usage of sunscreens in northwest England.

Sunscreens are employed with the aim of reducing the deleterious effects of ultraviolet radiation (UVR), but little is known about their use in the UK. This questionnaire survey assessed attitudes to and usage of sunscreens in northwest England in 2000. Subjects (186 females and 102 males) were recruited from the waiting rooms of four general practices, with a high response rate of 97%. Females were more frequent users of sunscreens than males, but only 35% females and 8% males reported their regular use. Twenty-two per cent of the study population did not use sunscreens at all, whereas 66% of subjects bought a sunscreen product once a year or less. Thirty-four per cent subjects reported experiencing sunburn in the last 2 years. Interestingly, more (60%) sunburns were found to occur at home in the UK than on holidays abroad, and these frequently occurred during outdoor activities other than deliberate sunbathing. There remains much scope for sunscreen education in the British public.