Amelanotic Melanocytes (amelanotic + melanocyte)

Distribution by Scientific Domains


Selected Abstracts


The hair follicle melanocytes in vitiligo in relation to disease duration

JOURNAL OF THE EUROPEAN ACADEMY OF DERMATOLOGY & VENEREOLOGY, Issue 8 2009
T S Anbar
Abstract Background and aims, Vitiligo is an acquired pigmentary disorder of skin and hair. Active melanocytes in hair follicles can be detected by DOPA and immunohistochemical staining, while amelanotic melanocytes can only be detected by the latter. None of the studies on hair melanocytes in vitiligo discussed the effect of disease duration on these melanocytes. Here, we study the presence of melanotic and amelanotic melanocytes in vitiligo hair follicles and statistically correlating their presence with the disease duration. Methods, This study was conducted on 30 patients with vitiligo and 10 normal volunteers. Three biopsies were taken from each patient: two from black and white hairs from vitiliginous areas and the third from apparently normal skin of the same patients. Sections were stained by DOPA reaction and NKI/beteb then examined for the presence of melanocytes. The presence of melanocytes and the disease duration were correlated statistically using the t -test. Results, Active melanocytes were detected in black hairs of 6.7% of vitiligo patients and in 100% of apparently normal skin of the same patients and controls. On examining black hairs of the 28 vitiligo patients with negative DOPA reaction, 19 of them (67.9%) showed positive NKI/beteb stain. Disease duration was inversely correlated with the melanocytes' presence within hair follicles. Melanocytes were absent from 100% of white hairs. Conclusions, The melanotic melanocytes were the first target of the disease process followed by the amelanotic melanocytes. Since the disappearance of the latter was inversely correlated with the disease duration, early treatment in vitiligo is advised. Conflicts of interest None declared. [source]


A modified method for purifying amelanotic melanocytes from human hair follicles

THE JOURNAL OF DERMATOLOGY, Issue 4 2006
Hui-Jun MA
ABSTRACT We describe a modified method for establishing long-term pure cultures of amelanotic melanocytes (AMMC) derived from human hair follicles. Normal human corpse scalp (just after death, 1 h) was transected 1 mm below the epidermis, and hair follicles in the remaining dermis were isolated by a two-step enzyme treatment. Hair follicle cell suspensions were prepared by 0.50% trypsin treatment for 30 min and cultured in an optimized melanoblast proliferation nature mitogen medium. Cells attached to the substratum were mostly amelanotic melanocytic in character with small, bipolar shapes in the early stage; only a few keratinocytes and rare fibroblasts were observed. Keratinocytes were easily removed by differential trypsinization. After the third passage, the proliferating cells were all amelanotic melanocytes as confirmed by immunostaining with polyclonal antibodies to ,PEP7h, which recognized the tyrosinase protein located on melanosomes and NKI/beteb, which is a pre-melanosomal antigen against synthetic peptides corresponding to the carboxyl termini of human melanosomal protein GP100. Cultured AMMC were highly positive to L-dopa reactivity after the addition of IBMX to the culture medium for 7 days. Many stage I and II melanosomes and occasional stage III melanosomes without stage IV melanosomes were found in the cytoplasm by transmission electron microscope. This modified technique is potentially more suitable for cultivating amelanotic melanocytes. The availability of pure cultures of hair-follicle amelanotic melanocytes will facilitate investigations of the roles of those cells in migration and differentiation during treatment of vitiligo. [source]