scholarly journals Clinical and Biological Characterization of Skin Pigmentation Diversity and Its Consequences on UV Impact

2018 ◽  
Vol 19 (9) ◽  
pp. 2668 ◽  
Author(s):  
Sandra Del Bino ◽  
Christine Duval ◽  
Françoise Bernerd

Skin color diversity is the most variable and noticeable phenotypic trait in humans resulting from constitutive pigmentation variability. This paper will review the characterization of skin pigmentation diversity with a focus on the most recent data on the genetic basis of skin pigmentation, and the various methodologies for skin color assessment. Then, melanocyte activity and amount, type and distribution of melanins, which are the main drivers for skin pigmentation, are described. Paracrine regulators of melanocyte microenvironment are also discussed. Skin response to sun exposure is also highly dependent on color diversity. Thus, sensitivity to solar wavelengths is examined in terms of acute effects such as sunburn/erythema or induced-pigmentation but also long-term consequences such as skin cancers, photoageing and pigmentary disorders. More pronounced sun-sensitivity in lighter or darker skin types depending on the detrimental effects and involved wavelengths is reviewed.

PEDIATRICS ◽  
1989 ◽  
Vol 84 (4) ◽  
pp. 612-612

In the commentary, "Sunburns, Melanoma, and the Pediatrician," by Williams and Sagebiel (Pediatrics 1989;84:381-382), three lines were omitted from the bottom of p 381. The whole paragraph is reprinted here. It is clear that a change is required in social perceptions in which a suntan is equated with health and beauty—not because suntans per se are unhealthy (the deleterious effects of ultraviolet light at suberythemogenic levels are not wellestablished), but because the persistent and often futile efforts of those who constitutionally have less pigment to achieve a tan have serious long-term health consequences. Ideally, there should be a social norm of beauty in which the natural differences in skin color are appreciated and black, tan, pink, and all shades in between are celebrated. Similarly, we need to change our thinking about freckles and solar lentigines. These are not "cute" but represent the ineffective efforts of melanocytes in genetically underpigmented skin to provide protective pigmentation in response to solar stress. Although pediatricians alone cannot change social concepts of beauty, we can instruct our patients and their families about sun protection and we can monitor them for early signs of excessive sun exposure. Weinstock et al demonstrated an increased risk of melanoma for those who had blistering sunburns in adolescence. Although they did not address the risk associated with sunburning prior to ages 15 years, it seems likely that these data can be applied to children of all ages. Therefore, instruction and sun protection should begin in infancy. Moreover, teenagers are known to be both highly conditioned by peer concepts of beauty and relatively impervious to the counsel of their elders. It is essential, therefore, that they enter these years with skin that has been well protected and with minds well indoctrinated.


2021 ◽  
Vol 12 ◽  
Author(s):  
Jingwen Wu ◽  
Zetong Lin ◽  
Genghua Chen ◽  
Qingbin Luo ◽  
Qinghua Nie ◽  
...  

Skin color is an important economic trait in meat-type chickens. A uniform bright skin color can increase the sales value of chicken. Chickens with bright yellow skin are more popular in China, especially in the broiler market of South China. However, the skin color of chickens can vary because of differences in breeds, diet, health, and individual genetics. To obtain greater insight into the genetic factors associated with the process of skin pigmentation in chickens, we used a colorimeter and high-resolution skin photographs to measure and analyze the skin color of chickens. By analyzing 534 chickens of the same breed, age, and feed condition, we found that the yellowness values of the chickens varied within this population. A significant positive correlation was found between the cloacal skin yellowness values before and after slaughter, and the cloacal skin yellowness value of live chickens was positively correlated with the overall body skin yellowness value. Additionally, chicken skin yellowness exhibited low heritability, ranging from 0.07 to 0.27. Through RNA sequencing, 882 genes were found to be differentially expressed between the skin with the highest and lowest yellowness values. Some of these differentially expressed genes may play an important role in yellow pigment deposition in chicken skin, which included TLR2B, IYD, SMOC1, ALDH1A3, CYP11A1, FHL2, TECRL, ACACB, TYR, PMEL, and GPR143. In addition, we found that the expression and variations of the BCO2 gene, which is referred to as the yellow skin gene, cannot be used to estimate the skin yellowness value of chickens in this population. These data will help to further our understanding of chicken skin yellowness and might contribute to the selection of specific chicken strains with consistent skin coloration.


Author(s):  
Adèle C. Green ◽  
Catherine M. Olsen ◽  
David J. Hunter

Skin cancer is one of the few types of cancer for which exposure to the major carcinogen, solar ultraviolet (UV) radiation, is strongly implicated on the basis of descriptive epidemiologic data alone. There are three major forms of skin cancer considered in this chapter—melanoma, basal cell carcinoma (BCC), and squamous cell carcinoma (SCC)—and each appears to have different causal relations to the pattern and total amount of sun exposure. High-intensity UV exposure and long-term UV exposure appear to be involved differentially in the various skin cancers and their subtypes. Underlying molecular mechanisms are becoming better understood, though many aspects like the cells of origin and the exact roles of intermediate lesions like actinic keratoses and nevi remain unclear. Because exposure of skin to UV radiation is modifiable, skin cancers are substantially preventable.


2021 ◽  
Vol 226 ◽  
pp. 00049
Author(s):  
Wuryantoro Wuryantoro ◽  
Ratna Mustika Wardhani ◽  
Indah Rekyani Puspitawati ◽  
Praptiningsih Gamawati Adinurani ◽  
Bohari Mohammad Yamin

“Uwi” (Dioscorea sp.) is a tuber plant species with potentials to support the national food diversity program because it has high tolerance when planted in upland areas, which are wide in Indonesia and beyond. The study aims to rescue germplasm of “Uwi” plants through exploration, identification, and collection for the sake of national long–term goal of providing alternative food sources to support food security. The research began with exploration of the west upland area of East Java, and continued with specimen planting for characterization testing in the following year. Exploration resulted in 127 samples of variants observed throughout uplands in Madiun, Ponorogo, Ngawi, Magetan and Pacitan, East Java, Indonesia with each result of 28, 26, 9, 20 and 44 variants. Five big groups of Dioscorea family namely Dioscorea alata, Dioscorea aculeata, Dioscorea hispida, Dioscorea pentaphylla and Dioscorea bulbifera were mapped out as a result. Using SPSS cluster analysis, D. alata as the most variant were specified into 20 groups and further gathered into seven clusters based on its main botanical characteristics of leaf shape, leaf color, stem color, tuber color, tuber shape, and skin color of the tuber. Meanwhile, D. aculeata and D. pentaphylla were each detailed into two sub–clusters and other types were each detailed into one.


Universe ◽  
2019 ◽  
Vol 5 (4) ◽  
pp. 91
Author(s):  
Valentina Raskina ◽  
Filip Křížek

The ALICE (A Large Ion Collider Experiment) experiment at CERN will upgrade its Inner Tracking System (ITS) detector. The new ITS will consist of seven coaxial cylindrical layers of ALPIDE silicon sensors which are based on Monolithic Active Pixel Sensor (MAPS) technology. We have studied the radiation hardness of ALPIDE sensors using a 30 MeV proton beam provided by the cyclotron U-120M of the Nuclear Physics Institute of the Czech Academy of Sciences in Řež. In this paper, these long-term measurements will be described. After being irradiated up to the total ionization dose 2.7 Mrad and non-ionizing energy loss 2.7 × 10 13 1 MeV n eq · cm - 2 , ALPIDE sensors fulfill ITS upgrade project technical design requirements in terms of detection efficiency and fake-hit rate.


2020 ◽  
Vol 21 (24) ◽  
pp. 9769
Author(s):  
Saaya Koike ◽  
Kenshi Yamasaki

The epidermis is located in the outermost layer of the living body and is the place where external stimuli such as ultraviolet rays and microorganisms first come into contact. Melanocytes and melanin play a wide range of roles such as adsorption of metals, thermoregulation, and protection from foreign enemies by camouflage. Pigmentary disorders are observed in diseases associated with immunodeficiency such as Griscelli syndrome, indicating molecular sharing between immune systems and the machineries of pigment formation. Melanocytes express functional toll-like receptors (TLRs), and innate immune stimulation via TLRs affects melanin synthesis and melanosome transport to modulate skin pigmentation. TLR2 enhances melanogenetic gene expression to augment melanogenesis. In contrast, TLR3 increases melanosome transport to transfer to keratinocytes through Rab27A, the responsible molecule of Griscelli syndrome. TLR4 and TLR9 enhance tyrosinase expression and melanogenesis through p38 MAPK (mitogen-activated protein kinase) and NFκB signaling pathway, respectively. TLR7 suppresses microphthalmia-associated transcription factor (MITF), and MITF reduction leads to melanocyte apoptosis. Accumulating knowledge of the TLRs function of melanocytes has enlightened the link between melanogenesis and innate immune system.


Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 368
Author(s):  
Lisdelys González-Rodríguez ◽  
Amauri Pereira de Oliveira ◽  
Lien Rodríguez-López ◽  
Jorge Rosas ◽  
David Contreras ◽  
...  

Ultraviolet radiation is a highly energetic component of the solar spectrum that needs to be monitored because is harmful to life on Earth, especially in areas where the ozone layer has been depleted, like Chile. This work is the first to address the long-term (five-year) behaviour of ultraviolet erythemal radiation (UVER) in Santiago, Chile (33.5° S, 70.7° W, 500 m) using in situ measurements and empirical modelling. Observations indicate that to alert the people on the risks of UVER overexposure, it is necessary to use, in addition to the currently available UV index (UVI), three more erythema indices: standard erythemal doses (SEDs), minimum erythemal doses (MEDs), and sun exposure time (tery). The combination of UVI, SEDs, MEDs, and tery shows that in Santiago, individuals with skin types III and IV are exposed to harmfully high UVER doses for 46% of the time that UVI indicates is safe. Empirical models predicted hourly and daily values UVER in Santiago with great accuracy and can be applied to other Chilean urban areas with similar climate. This research inspires future advances in reconstructing large datasets to analyse the UVER in Central Chile, its trends, and its changes.


Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 332
Author(s):  
Luca Fania ◽  
Francesca Sampogna ◽  
Francesco Ricci ◽  
Mariafrancesca Hyeraci ◽  
Andrea Paradisi ◽  
...  

Background: Systemic photoprotection (i.e., administration of substances such as nicotinamide, carotenoids, and vitamin D) may be important to reduce photocarcinogenesis or to support long-term protection against UV irradiation. Clinical trials showed that oral nicotinamide is effective in reducing the onset of new nonmelanoma skin cancers (NMSCs), while other oral photoprotectors failed to achieve the reduction of new melanoma or NMSC formation in humans. The aim of this study was to summarize the current state of knowledge of systemic photoprotection and to evaluate the knowledge and attitude of dermatologists regarding these treatments. Methods: The survey was conducted on a sample of dermatologists recruited according to a snowball sampling procedure. The questionnaire consisted of a first part asking for characteristics of the participant and a second part with 12 specific questions on their knowledge about systemic photoprotection, particularly their knowledge of astaxanthin, β-carotene, nicotinamide, and vitamin D3. Results: One hundred eight dermatologists answered the survey. Most of them (85.2%) stated that oral photoprotectors have a role in the prevention of skin cancer, and responses mainly mentioned nicotinamide. More than half of them (54.6%) had prescribed all the considered oral photoprotectors, but the majority of them had prescribed nicotinamide, mainly for 2 to 3 months during summer, almost invariably (n = 106) associated with topical photoprotectors. Most dermatologists (>80%) were aware of scientific publications demonstrating an effect of systemic photoprotectors on NMSC. Conclusions: Most Italian dermatologists have positive views on oral photoprotection in skin cancer and are aware of the demonstrated potential of nicotinamide in the prevention of NMSCs.


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