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Red Melanin

Mi Young Noh, Subbaratnam Muthukrishnan, Karl J Kramer, Yasuyuki Arakane
Adult beetles (Coleoptera) are covered primarily by a hard exoskeleton or cuticle. For example, the beetle elytron is a cuticle-rich highly modified forewing structure that shields the underlying hindwing and dorsal body surface from a variety of harmful environmental factors by acting as an armor plate. The elytron comes in a variety of colors and shapes depending on the coleopteran species. As in many other insect species, the cuticular tanning pathway begins with tyrosine and is responsible for production of a variety of melanin-like and other types of pigments...
October 2016: Current Opinion in Insect Science
John W Rowe, David L Clark, Rebecca A Mortensen, Carolyn V Commissaris, Lawrence W Wittle, John K Tucker
Color and pigmentation patterns of the integument can facilitate crypsis, thermoregulation, and social signaling. According to the "thermal melanism hypothesis", cold environmental temperature should increase the quantity of melanin that is deposited in the integument thereby facilitating radiative warming. We studied the influences of water temperature (26°C or 31°C) and substrate color (black or white) on the degree of melanization in the red-eared slider, Trachemys scripta elegans, under laboratory conditions...
October 2016: Journal of Thermal Biology
Willow R Lindsay, Douglas G Barron, Michael S Webster, Hubert Schwabl
In males it is frequently testosterone (T) that activates the expression of sexually selected morphological and behavioral displays, but the role of T in regulating similar traits in females is less clear. Here, we combine correlational data with results from T and gonadotropin-releasing hormone (GnRH) manipulations in both sexes to assess the role of T in mediating sexually dimorphic coloration and morphology in the red-backed fairy-wren (Malurus melanocephalus). We show that: (1) natural variation in female expression of ornamental traits (darkened bills and red back feathers) is positively associated with age and circulating androgen titres, (2) females have the capacity to express most male-typical traits in response to exogenous T, including carotenoid-pigmented body plumage, shorter feathers, darkened bill and enlarged cloacal protuberance, but (3) appear constrained in production of male-typical melanin-pigmented plumage, and (4) low androgen levels during the pre-nuptial molt, probably because of low ovarian capacity for steroid production (or luteinizing hormone sensitivity), prevent females from developing male-like ornamentation...
October 1, 2016: Journal of Experimental Biology
Masayo Aoki, Satoshi Akaishi, Junichi Nakao, Teruyuki Dohi, Hiko Hyakusoku, Rei Ogawa
BACKGROUND: Keloids are characterized by the formation of excessive scar tissue that extends beyond the area of the initial wound. Keloid redness is due to angiogenesis and chronic inflammation and is an important indicator of the severity of the lesion and the effectiveness of treatment. METHODS: The color of 33 untreated keloids from 30 patients was measured with a narrow-band reflectance colorimeter. The erythema and melanin levels in the keloids (Ek and Mk, respectively) were recorded with control data obtained from the flexor aspect of the forearm (Ec and Mc, respectively)...
2016: Journal of Nippon Medical School, Nippon Ika Daigaku Zasshi
Xiujun Sun, Zhihong Liu, Liqing Zhou, Biao Wu, Yinghui Dong, Aiguo Yang
The Yesso scallop Patinopecten yessoensis displays polymorphism in shell colors, which is of great interest for the scallop industry. To identify genes involved in the shell coloration, in the present study, we investigate the transcriptome differences by Illumina digital gene expression (DGE) analysis in two extreme color phenotypes, Red and White. Illumina sequencing yields a total of 62,715,364 clean sequence reads, and more than 85% reads are mapped into our previously sequenced transcriptome. There are 25 significantly differentially expressed genes between Red and White scallops...
2016: PloS One
Bodo D Wilts, Marco A Giraldo, Doekele G Stavenga
BACKGROUND: Ultrastructures in butterfly wing scales can take many shapes, resulting in the often striking coloration of many butterflies due to interference of light. The plethora of coloration mechanisms is dazzling, but often only single mechanisms are described for specific animals. RESULTS: We have here investigated the male Rajah Brooke's birdwing, Trogonoptera brookiana, a large butterfly from Malaysia, which is marked by striking, colorful wing patterns...
2016: Frontiers in Zoology
Sara Zakerin, Shirin Fahimi, Maedeh Rezghi
BACKGROUND: Freckles are numerous pigmented spots of the skin, mainly confined to the face, even arms and back. Although freckles are light-brown macules, most frequently observed in individuals with red or blond hair, they are common to Asian people too. Freckles increase in number, size, and depth of pigmentation during the summer months. Histologically, freckles show increased production of melanin pigment by a normal number of melanocytes. Freckles commonly stop spreading before adolescence and last for life, but could sometimes be subtle in adulthood...
May 2016: Iranian Journal of Medical Sciences
Lester M Davids, Jennifer C Van Wyk, Nonhlanhla P Khumalo
Glutathione (GSH) is the most abundant naturally occurring non-protein thiol that protects mammalian cells from oxidative stress. Intravenous (IV) GSH for skin lightening is advertised by clinics in South Africa and internationally online, yet to date no published review on the subject exists. Methods. We conducted a MEDLINE search (to 30 September 2015) of GSH use for skin lightening and of all indications in medicine, to evaluate its safety. Results. Two controlled clinical trials (GSH capsules: 60 patients; 2% glutathione disulphide lotion: 30 patients) and a case series (GSH lozenges: 30 patients) reported a significantly decreased melanin index...
August 2016: South African Medical Journal, Suid-Afrikaanse Tydskrif Vir Geneeskunde
Ahmed H Mahmoud, Ashraf M Mashaly, Khalid M Al-Anazi, Ahmed M Rady, Amgad A Saleh
The melanocortin-1 receptor (MC1R) is one of the key genes involved in regulating mammalian eyes, skin and hair color. The MC1R protein is located on the plasma membrane of melanocytes, specialized cells that produce the pigment melanin through melanogenesis process. In this study, the complete coding region of MC1R gene including parts of 3' and 5' untranslated regions was amplified and sequenced from three indigenous Saudi sheep; Najdi (generally black, n = 41), Naeimi (generally brown, n = 36) and Herri (generally white, n = 18), in addition to 13 Sawaknee sheep, an exotic brown breed originally from Sudan...
August 4, 2016: Asian-Australasian Journal of Animal Sciences
Chuan Hu, Yongmei Liu, Jiantao Chen, Qin He, Huile Gao
Carbonaceous dots (CDs) are superior nanomaterials owing to their promising luminescence properties and good biocompatibility. However, most CDs have relatively short excitation/emission, which restrict their application in bioimaging. In this study, a simple one-step procedure was developed for synthesis of melanin-originated CDs (MNPs). The MNPs showed two long red shift emissions at 570nm and 645nm with broad absorptions from 200nm to 400nm and 500nm to 700nm, suggesting the great potential of MNPs in bioimaging...
October 15, 2016: Journal of Colloid and Interface Science
Raul Cabrera, Susana Puig, Jorge Larrondo, Alex Castro, Karen Valenzuela, Natalia Sabatini
The face has not been considered a common site of fixed drug eruption, and the authors lack dermatoscopic studies of this condition on the subject. The authors sought to characterize clinical and dermatoscopic features of 8 cases of an eruptive facial postinflammatory lentigo. The authors conducted a retrospective review of 8 cases with similar clinical and dermatoscopic findings seen from 2 medical centers in 2 countries during 2010-2014. A total of 8 patients (2 males and 6 females) with ages that ranged from 34 to 62 years (mean: 48) presented an abrupt onset of a single facial brown-pink macule, generally asymmetrical, with an average size of 1...
June 29, 2016: American Journal of Dermatopathology
Trenton C Shrader, James W Carpenter, Ada Giselle Cino-Ozuna, Gordon A Andrews
A 20-year-old, female African grey parrot ( Psittacus erithacus erithacus) was examined because of ataxia and weakness. Radiographs were unremarkable, and results of a complete blood cell count revealed leukocytosis and heterophilia. Because of poor response to therapy with meloxicam, doxycycline, and enrofloxacin; deteriorating condition; and poor prognosis, the parrot was euthanatized. Postmortem examination revealed 2 dark red nodules in the liver. No grossly visible mass was observed in the syrinx. Histologic examination of the liver and syrinx revealed similar foci of round, oval, and polygonal cells exhibiting severe pleomorphism, with poorly demarcated cytoplasmic borders and moderate amounts of eosinophilic cytoplasm containing brown to black granules (melanin)...
June 2016: Journal of Avian Medicine and Surgery
Ioana Baldea, Diana Elena Olteanu, Pompei Bolfa, Flaviu Tabaran, Rodica-Mariana Ion, Gabriela Adriana Filip
Melanoma, a cancer derived from melanocytes is very difficult to treat, especially in advanced cases. There are several encouraging studies of the efficacy of photodynamic therapy (PDT) in melanoma. However, PDT has to overcome the main defense mechanisms like: defects in the apoptotic pathways, pigmentation, sequestration of the photosensitisers (PS) inside melanosomes and increased oxidative stress defense. Two meso-substituted porphyrins, meso-5,10,15,20-tetrakis (4-hydroxyphenyl) porphyrin (THOPP) and meso-5-(4-hydroxyphenyl)-10, 15, 20-tris (4-methoxyphenyl) porphyrin (THOMPP) were used as PS to investigate several mechanisms underlining the PDT anti-melanoma effects, on a lightly pigmented melanoma cell line (WM35), in vitro...
August 2016: Journal of Photochemistry and Photobiology. B, Biology
Marion Chatelain, Julien Gasparini, Adrien Frantz
Trace metals from anthropogenic activities are involved in numerous health impairments and may therefore select for detoxification mechanisms or a higher tolerance. Melanin, responsible for the black and red colourations of teguments, plays a role in metal ion chelation and its synthesis is positively linked to immunity, antioxidant capacity and stress resistance due to pleiotropic effects. Therefore, we expected darker birds to (1) store higher amounts of metals in their feathers, (2) maintain lower metal concentrations in blood and (3) suffer less from metal exposure...
July 2016: Global Change Biology
Caradee Y Wright, Aletta E Karsten, Marcus Wilkes, Ann Singh, Johan du Plessis, Patricia N Albers, Petrus A Karsten
Melanin provides protection against excess exposure to solar ultraviolet radiation (UVR) and related adverse health effects. Diffuse reflectance spectroscopy (DRS) can be used to calculate cutaneous melanin and erythema, but this is complex and has been mostly used for light-to-medium pigmented skin. Handheld reflectance spectrophotometers, such as the Mexameter(®) MX18, can also be used. We compared DRS-calculated melanin and erythema values with Mexameter melanin and erythema index values to understand how these techniques/measurements correlate in an African population of predominantly deeply pigmented skin...
July 2016: Photochemistry and Photobiology
Tal Ben Ami, Yuehong Tong, Alauddin Bhuiyan, Carrie Huisingh, Zsolt Ablonczy, Thomas Ach, Christine A Curcio, R Theodore Smith
PURPOSE: Discovery of candidate spectra for abundant fluorophore families in human retinal pigment epithelium (RPE) by ex vivo hyperspectral imaging. METHODS: Hyperspectral autofluorescence emission images were captured between 420 and 720 nm (10-nm intervals), at two excitation bands (436-460, 480-510 nm), from three locations (fovea, perifovea, near-periphery) in 20 normal RPE/Bruch's membrane (BrM) flatmounts. Mathematical factorization extracted a BrM spectrum (S0) and abundant lipofuscin/melanolipofuscin (LF/ML) spectra of RPE origin (S1, S2, S3) from each tissue...
May 2016: Translational Vision Science & Technology
Raffaella Micillo, Lucia Panzella, Kenzo Koike, Giuseppe Monfrecola, Alessandra Napolitano, Marco d'Ischia
Recent advances in the chemistry of melanins have begun to disclose a number of important structure-property-function relationships of crucial relevance to the biological role of human pigments, including skin (photo) protection and UV-susceptibility. Even slight variations in the monomer composition of black eumelanins and red pheomelanins have been shown to determine significant differences in light absorption, antioxidant, paramagnetic and redox behavior, particle morphology, surface properties, metal chelation and resistance to photo-oxidative wear-and-tear...
2016: International Journal of Molecular Sciences
Kam Lun Hon, Chi Kong David Luk, Yin Ching Tsang, Nga Hin Pong, Ting Fan Leung
BACKGROUND: Atopic dermatitis (AD) or eczema is an inflammatory skin disease associated with significant impairment of quality of life. It is important to objectively quantify cutaneous biophysical measurements in research and therapeutics of this disease. OBJECTIVE: To evaluate if skin redness (erythema) and pigmentation (melanin) correlate with disease severity and quality of life. METHODS: Redness and pigmentation were measured under standardized condition at the antecubital flexure...
May 6, 2016: Journal of Dermatological Treatment
Khai Khuang Cheong, Caroline Strub, Didier Montet, Noël Durand, Pascaline Alter, Jean-Christophe Meile, Sabine Schorr Galindo, Angélique Fontana
The effects of light at different wavelengths and photoperiod on growth and ochratoxin A production of Aspergillus carbonarius and Aspergillus westerdijkiae were studied: far-red (740 nm), red (625 nm), blue (445 nm), and UV-A (366 nm). Fungal growth was not significantly affected by photoperiod or light wavelength; the only exception was A. westerdijkiae which showed reduced growth under UV-A light (366 nm). Short-wavelength blue light (445 nm) and UV-A light caused a reduction in ochratoxin A production of both fungal species...
May 2016: Fungal Biology
Douglas E Brash
Mutations in sunlight-induced melanoma arise from cyclobutane pyrimidine dimers (CPDs), DNA photoproducts usually created picoseconds after an ultraviolet (UV) photon is absorbed at thymine or cytosine. Surprisingly, we found that, in melanocytes, CPDs were generated for hours after UVA or UVB exposure. These "dark CPDs" constituted the majority of CPDs in cultured human and murine melanocytes and in mouse skin, and they were most prominent in skin containing pheomelanin, the melanin responsible for blonde and red hair...
June 2016: Toxicologic Pathology
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