Eumelanin
Mostrando 1-12 de 17 artigos, teses e dissertações.
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1. Evaluation of melanin production by Sporothrix luriei
There is a paucity of studies on the cell biology of Sporothrix luriei, the less common of the pathogenic Sporothrix species worldwide. The production of DHN-melanin, eumelanin, and pyomelanin were evaluated on the mycelial and yeast forms of the S. luriei ATCC 18616 strain. The mycelial form of this species produced only pyomelanin, which protected the fung
Mem. Inst. Oswaldo Cruz. Publicado em: 2018-01
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2. Diversity among populations goats based on morphometric markers / Diversidade genética entre populações caprinas com base em marcadores morfométricos
The goats were introduced in Brazil by the Portuguese colonizers. Today it is difficult to accurately identify the origin of the Brazilian domestic animals and it is unknown the entire extent of its diversity. The conservation and breeding of domestic animals depend on diversity in the species concerned. Theobjectives of this study were 1. compare different
Publicado em: 2009
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3. Estudo da interação entre porfirinas e eumelanina sintética / Study of porphyrin-synthetic eumelanin interaction
Foram investigadas através da técnica de absorção eletrônica Uv-Vis e emissão de fluorescência a interação entre uma série de porfirinas e zinco-porfirinas com o polímero de eumelanina sintética obtida pela auto-oxidação da L-DOPA (dihidroxi-fenilalanina). Ocorre a formação de dois complexos na interação entre as porfirinas catiônicas e a
Publicado em: 2005
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4. Is there any difference in the photobiological properties of melanins isolated from human blue and brown eyes?
Investigations were carried out to determine whether the melanin present in the blue and brown eyes were eumelanin, the melanin present in black hair and dark skin, or pheomelanin, the melanin present in red hair and the skin of people with red hair. Our results showed that UV-visible irradiation of blue or brown eye melanin did not produce any superoxide. I
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5. Characterization of genes modulated during pheomelanogenesis using differential display
Molecular and biochemical mechanisms that modulate the production of eumelanin or pheomelanin pigments involve the opposing effects of two intercellular signaling molecules, α-melanocyte stimulating hormone (MSH) and agouti signal protein (ASP). ASP is an antagonist of MSH signaling through the melanocyte-specific MSH receptor, although its mechanism(s) of
The National Academy of Sciences.
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6. Melanin Biosynthesis in Cryptococcus neoformans
Pigment production by Cryptococcus neoformans is virulence associated. Dopamine- and 3,4-dihydroxyphenylalanine–melanin products were identified after acidic permanganate oxidation, alkaline hydrogen peroxide oxidation, or hydrolysis with hydriodic acid. These data provide direct chemical evidence for the formation of eumelanin polymers by catecholamine ox
American Society for Microbiology.
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7. Catecholamine Oxidative Products, but Not Melanin, Are Produced by Cryptococcus neoformans during Neuropathogenesis in Mice
Melanin has been proposed as a virulence factor in Cryptococcus neoformans, but its presence has not been shown unambiguously in vivo. Validated methods used previously to show production of cryptococcal eumelanin pigment in vitro (P. R. Williamson, K. Wakamatsu, and S. Ito, J. Bacteriol. 180:1570–1572, 1998) were used to assess for production of laccase-d
American Society for Microbiology.
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8. Melanin acts as a potent UVB photosensitizer to cause an atypical mode of cell death in murine skin
Melanin protects the skin against DNA damage induced by direct absorption of sunlight's UV radiation. Yet, irradiating melanin in vitro or in cultured cells also generates active oxygen species such as superoxide, which can indirectly induce oxidative base lesions and DNA strand breaks. This photosensitization is greater for pheomelanin (yellow and red melan
National Academy of Sciences.
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9. Mesoderm-Ectoderm Interaction in the Production of the Agouti Pigmentation Pattern in Mice
Alleles at the agouti locus in the mouse determine the synthesis of either phaeomelanin or eumelanin by follicular melanocytes by altering the hair follicle environment. The method of dermal-epidermal recombination of mouse skin from C57BL/6J a/a and C57BL/6J Aw-J/Aw-J embryos was used in this study to establish the precise site of agouti gene action within
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10. Temperature-sensitive tyrosinase associated with peripheral pigmentation in oculocutaneous albinism.
Several types of autosomal recessive oculocutaneous albinism (OCA) are associated with abnormal tyrosinase function and a generalized reduction in or absence of cutaneous and eye melanin. Each is thought to result from a different mutant allele at the tyrosinase locus, with the mutation producing an enzyme with little or no activity in all involved tissues.
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11. Allelic Variation within the Emv-15 Locus Defines Genomic Sequences Closely Linked to the agouti Locus on Mouse Chromosome 2
Gene(s) at the agouti locus act within the microenvironment of the hair follicle to switch pigment synthesis in the melanocyte between eumelanin (black or brown pigment) and phaeomelanin (yellow pigment). Many phenotypic variants of this locus have been described. The mechanism(s) of gene action causing such variation in coat-color phenotype is not known. Th
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12. Molecular Genetics of the Brown (B)-Locus Region of Mouse Chromosome 4. I. Origin and Molecular Mapping of Radiation- and Chemical-Induced Lethal Brown Deletions
Over a period of many years, germ-cell mutagenesis experiments using the mouse specific-locus test have generated numerous radiation- and chemical-induced alleles of the brown (b; Tyrp1) locus in mouse chromosome 4. We describe here the origin, maintenance and initial molecular characterization of 28 b mutations that are prenatally lethal when homozygous. Ea