No abstract available.
Hypopigmentation* ; Melanins* ; Melanocytes* ; Melanosis*

BACKGROUND: The growth of cells is closely related to components in a culture medium. There are many reports about cellular characteristics of melanocytes grown in a PMA-contained medium. However, only a few reports have been studied by using a physiologic mitogens-contained medium. To understand melanocyte in vivo, it is necessary to know the cellular biology of melanocytes grown in a physiologic mitogens-contained medium. OBJECTIVE: To investigate any differences between melanocytes grown in phorbol 12-myristate 13-acetate(PMA)-contained medium and in physiologic mitogens-contained medium. METHOD: We examined morphology, number and melanin contents of cultured human melanocytes grown in a PMA-contained medium and physiologic mitogens-, such as bFGF, ET-1 and a a-MSH contained medium. Result : The results are summarized as follows : 1. There were no significant morphologic differences between cells in PMA-contained medium and in physiologic mitogens-contained medium. 2. The number of melanocytes were significantly more numerous in PMA-contained medium on the 2nd day (p<0.05), but significantly less numerous in the same medium on the 6th day (p<0.05). So, the proliferation rate of melanocytes in PMA-contained medium became lower than in physiologic mitogens-contained medium as time went by. 3. Melanocytes grown in PMA-contained medium had significantly increased melanin contents regardless of the time (p<0.05). Conclusion : The proliferation of melanocytes was better in physiologic mitogens-contained medium, the melanization was higher in melanocytes of PMA-contained medium.
Humans* ; Melanins ; Melanocytes*

No abstract available.
Humans* ; Melanocytes* ; Tretinoin*

No abstract available.
Hair* ; Melanocytes* ; Nevus, Halo*

Agminated lentigines may be defind as a circumscribed grouping of small pigmented macules arranged in a small or large group, often in a segmental pattern, each macule consisting of a lentiginous epidermal proliferation of melanocytes. We report five cases of agminated lentigines in otherwise healthy persons. Histologic exarnination of the pigmented lesion revealed findings consistent with lentigo simplex.
Humans ; Lentigo* ; Melanocytes

No abstract available.
Eczema ; Inflammation ; Melanocytes ; Nevus

No abstract available.
Lasers, Solid-State* ; Melanocytes* ; Nevus*

It has been generally assumed that eccrine poroma ariees from acroayringium, epidermal sweat duct unit. One of the characteriatics of thie structure is abaence of melanocytes and melanin granules among ite cells. Hmvever, a cornplete abeence of melanocytes and melanin granules in eccrine poroma is not invariable and a few reparts of such an occurrenee were presented, We report a case of eccrine poroma on the area below lateral malleolus af left foot. Microscpically melanin granules, confirmed by the use of Fontana Masson stain, were found in some of the tumor cells.
Foot ; Melanins* ; Melanocytes ; Poroma* ; Sweat

Humans ; Melanocytes ; Melanosis ; Fibroblasts ; Skin

Melanoacanthoma is a variant of seborrheic keratosis which was first introduced by Mishima and Pinkus in 1960. This is a very rare and benign, epidermal tumor. Clinically, it is usually manifested in a pigmented, verrucous, round or oval plaque and nodular lesion. This is characterized histologically by nonpigmented keratinocytes and numerous large, richly dendritic melanocytes. We describe a 68-year-old man who suffered from a black-colored plaque on his right shin for 5 years. Melanoacanthoma was diagnosed by characteristic histopathologic findings.
Aged ; Humans ; Keratinocytes ; Keratosis, Seborrheic ; Melanocytes