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Pigmentation Changes (pigmentation + change)
Selected AbstractsStandardization of In Vitro Macrophotography for Assessment of Cutaneous ResponsesPHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 4 2009Sergio G. Coelho The increased popularity of commercially available three-dimensional human skin equivalents in recent years has allowed for assessment of melanogenesis modulated by compounds topically applied to the skin or directly incorporated from the medium. These skin equivalents provide a suitable model for elucidating the mechanisms of action of various factors that modulate skin pigmentation or other properties of the skin. As such, researchers need to objectively quantify cutaneous responses at the macroscopic level. A simple method to standardize macrophotography images is reported that can quantify cutaneous responses in human skin equivalents of Asian, Black or African American, and Caucasian or White racial/ethnic origin. Macrophotographs are analyzed using the Commission Internationale de l'Eclairage L*a*b* color space system in combination with a personal computer and image editing software. Pigmentation changes monitored over a 9 day period showed a high correlation with melanin content evaluated in Fontana,Masson-stained sections. These results indicate the feasibility of using a macrophotography setup in a sterile tissue culture environment to objectively assess in vitro cutaneous responses in human skin equivalents. This serves as an adjunct tool to biochemical and morphological methods to effectively quantify changes in pigmentation over time. [source] The halo effect: avoiding adverse pigmentation changes following Q-switched ruby laser treatment of pigmented birthmarksJOURNAL OF COSMETIC DERMATOLOGY, Issue 3 2006Daniel C Widdowson MBBS [source] Characterization of two melanin-concentrating hormone genes in zebrafish reveals evolutionary and physiological links with the mammalian MCH systemTHE JOURNAL OF COMPARATIVE NEUROLOGY, Issue 5 2009Jennifer R. Berman Abstract Melanin-concentrating hormone (MCH) regulates feeding and complex behaviors in mammals and pigmentation in fish. The relationship between fish and mammalian MCH systems is not well understood. Here, we identify and characterize two MCH genes in zebrafish, Pmch1 and Pmch2. Whereas Pmch1 and its corresponding MCH1 peptide resemble MCH found in other fish, the zebrafish Pmch2 gene and MCH2 peptide share genomic structure, synteny, and high peptide sequence homology with mammalian MCH. Zebrafish Pmch genes are expressed in closely associated but non-overlapping neurons within the hypothalamus, and MCH2 neurons send numerous projections to multiple MCH receptor-rich targets with presumed roles in sensory perception, learning and memory, arousal, and homeostatic regulation. Preliminary functional analysis showed that whereas changes in zebrafish Pmch1 expression correlate with pigmentation changes, the number of MCH2-expressing neurons increases in response to chronic food deprivation. These findings demonstrate that zebrafish MCH2 is the putative structural and functional ortholog of mammalian MCH and help elucidate the nature of MCH evolution among vertebrates. J. Comp. Neurol. 517:695,710, 2009. © 2009 Wiley-Liss, Inc. [source] Effects of latanoprost in iris bioidentificationACTA OPHTHALMOLOGICA, Issue 5 2009Heikki Lamminen Abstract. Purpose:, Bioidentification is becoming increasingly important in everyday life. One of the most widespread methods of bioidentification is based on the structure of the iris. Iris photography has several advantages as an identification method: it is relatively simple and effective; it is non-invasive, and it is comparatively inexpensive. However, some medical conditions may change the appearance of the iris. This paper discusses the effects of latanoprost-induced pigmentation changes in iris bioidentification. Methods:, The study is based on four extreme cases of latanoprost-induced pigmentation changes. Iris photographs in these patients during treatment are compared with pretreatment photographs. The comparison is carried out with iris recognition software developed by our research group based on the principles of Daugman's well-known IrisCode. The system was evaluated with 595 iris comparisons. Results:, Iris photographs showing latanoprost-induced pigmentation changes were correctly matched with pretreatment photographs of the same irises with an error probability similar to that for matching equivalent pairs of photographs in intact eyes. Conclusions:, Our results indicate that the pigmentation changes studied do not seem to have a significant effect on the standard identification algorithm. [source] | |||||||||||||