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Melanocyte Number (melanocyte + number)

Distribution by Scientific Domains
Medical Sciences100%

Selected Abstracts

Application of computerized image analysis in pigmentary skin diseases

INTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 1 2001
Eun-So Lee MD
Background Melanocyte number and the amount of melanin pigment are related to diagnosis and treatment of pigmentary skin diseases. Various histologic methods are used, such as Fontana-Masson stain for melanin pigment or immunohistochemical stain for melanocytes. Recently, computerized image analysis has been applied to many fields to avoid interobserver bias. In this study, we applied a computerized image analysis to assess the melanin content and melanocyte density of human epidermis. Methods We evaluated the skin biopsy specimens (paraffin blocks) from normal human skin (33 ± 6.6, n = 11) and diseased skins; vitiligo (32 ± 10.0, n = 8), melasma (35 ± 8.6, n = 11), and lentigo senilis (40 ± 7.2, n = 11) (mean age ± SD). Each specimen was stained with Fontana,Masson for melanin pigments and immunohistochemical method for melanocytes. Quantitative analysis of melanin pigment and melanocyte number (density) were investigated through two methods: (1) two dermatologists measured the visual scales; and (2) computerized image analysis was used to measure melanin content indices (MCI). The data were evaluated using one-way anova. Results The visual scale of the Fontana,Masson stain was the highest for lentigo senilis (3.8 ± 0.40), followed by melasma (2.6 ± 0.67), normal skin (1.8 ± 0.60) and vitiligo (0) (P < 0.05). These findings were consistent with objective measurements made by computerized image analysis. MCI values were 120.3 ± 20.74 for lentigo senilis, 81.1 ± 19.27 for melasma, 45.5 ± 16.92 for normal skin, and 0.3 ± 0.30 for vitiligo in decreasing order (P < 0.05). MC/1E (melanocyte number per 1 mm epidermis) was about two fold larger in lentigo senilis (18.1 ± 8.92) than melasma (9.7 ± 2.40) or normal skin (9.3 ± 2.67) (P < 0.05). MC/1B (melanocyte number per 1 mm basal layer) was about 1.5 fold higher in lentigo senilis (13.5 ± 4.17), compared to normal skin (9.0 ± 3.55) (P < 0.05). Melasma showed increased melanocyte numbers compared to normal skin, but it was not statistically significant (P > 0.05). Conclusion We believe this computerized image analysis could be useful tool for diagnosis and comparison of interval changes in pigmentary diseases like melasma or lentigo senilis by quantifying melanin pigments or melanocytes in skin biopsy specimens. [source]

A review of genetic disorders of hypopigmentation: lessons learned from the biology of melanocytes

EXPERIMENTAL DERMATOLOGY, Issue 9 2009
Clio Dessinioti
Abstract:, Inherited diseases of pigmentation were among the first traits studied in humans because of their easy recognition. The discovery of genes that regulate melanocytic development and function and the identification of disease-causative mutations have greatly improved our understanding of the molecular basis of pigmentary genodermatoses and their underlying pathogenetic mechanisms. Pigmentation mutants can account for hypo-/amelanosis, with or without altered melanocyte number, resulting in different phenotypes, such as Waardenburg syndrome, piebaldism, Hermansky-Pudlak syndrome, Chediak-Higashi syndrome, oculocutaneous albinism and Griscelli syndrome. In this review, we summarize the basic concepts of melanocyte biology and discuss how molecular defects in melanocyte development and function can result in the development of hypopigmentary hereditary skin diseases. [source]

Application of computerized image analysis in pigmentary skin diseases

INTERNATIONAL JOURNAL OF DERMATOLOGY, Issue 1 2001
Eun-So Lee MD
Background Melanocyte number and the amount of melanin pigment are related to diagnosis and treatment of pigmentary skin diseases. Various histologic methods are used, such as Fontana-Masson stain for melanin pigment or immunohistochemical stain for melanocytes. Recently, computerized image analysis has been applied to many fields to avoid interobserver bias. In this study, we applied a computerized image analysis to assess the melanin content and melanocyte density of human epidermis. Methods We evaluated the skin biopsy specimens (paraffin blocks) from normal human skin (33 ± 6.6, n = 11) and diseased skins; vitiligo (32 ± 10.0, n = 8), melasma (35 ± 8.6, n = 11), and lentigo senilis (40 ± 7.2, n = 11) (mean age ± SD). Each specimen was stained with Fontana,Masson for melanin pigments and immunohistochemical method for melanocytes. Quantitative analysis of melanin pigment and melanocyte number (density) were investigated through two methods: (1) two dermatologists measured the visual scales; and (2) computerized image analysis was used to measure melanin content indices (MCI). The data were evaluated using one-way anova. Results The visual scale of the Fontana,Masson stain was the highest for lentigo senilis (3.8 ± 0.40), followed by melasma (2.6 ± 0.67), normal skin (1.8 ± 0.60) and vitiligo (0) (P < 0.05). These findings were consistent with objective measurements made by computerized image analysis. MCI values were 120.3 ± 20.74 for lentigo senilis, 81.1 ± 19.27 for melasma, 45.5 ± 16.92 for normal skin, and 0.3 ± 0.30 for vitiligo in decreasing order (P < 0.05). MC/1E (melanocyte number per 1 mm epidermis) was about two fold larger in lentigo senilis (18.1 ± 8.92) than melasma (9.7 ± 2.40) or normal skin (9.3 ± 2.67) (P < 0.05). MC/1B (melanocyte number per 1 mm basal layer) was about 1.5 fold higher in lentigo senilis (13.5 ± 4.17), compared to normal skin (9.0 ± 3.55) (P < 0.05). Melasma showed increased melanocyte numbers compared to normal skin, but it was not statistically significant (P > 0.05). Conclusion We believe this computerized image analysis could be useful tool for diagnosis and comparison of interval changes in pigmentary diseases like melasma or lentigo senilis by quantifying melanin pigments or melanocytes in skin biopsy specimens. [source]