Melanosomes were isolated from the human hair by graded centrifugation and identified by transmission and scanning electron microscopic examination. Melanosomes were separated from the keratinous structures by treating with strong NaOH solution for 15 hours. The keratinous structures were removed by centrifugation ai 2,500xg and 3,500xg for 10 minutes respectively at 0 ℃. The isolated melanosomes were collected by centrifugation at 7,800xg at 0 ℃. Scanning electron microscopic examination made it possible to evaluate the global structure of purified melanosomes.
Centrifugation ; Hair* ; Humans* ; Melanosomes* ; Microscopy, Electron, Scanning

No abstract available.
Adult* ; Humans ; Melanosomes* ; Pilot Projects* ; Skin* ; Zebrafish*

Electron microscopic examination of specimens from lesions of eight patients with hyperpigmented and six patients with hypopigmented tinea versicolor and from unaffected skin in each patient was performed. The results are summarized as follows; 1. In hyperpigmented lesions, melanosomes are larger and more singly dispersed than in unaffected skin. 2. In hypopigmented lesions, melanosomes are smaller and less singly diepersed than in unaffected skin. 3. Number of total melanosomes in hyperpigmented and hypopigmented lesions was not different from in unaffected skin.
Humans ; Melanosomes* ; Skin ; Tinea Versicolor* ; Tinea*

We studied 25 cases of clinically diagnosed erythema dyschrornicum perstans (EDP) who were seen in our clinic within 11-year period, from 1975 through 1985, and compared light and electron microscopic findings, and direct immunoflunrescence findings. The results are summarized as follows: 1. There were 16 males(64%) and 9 females(36%). The peak age incidence was in the second decade. 2. The mean age of onset was 18 years(M: 16. 6, F: 19. 4) and the rnean duration was 1.8 years(M: 2.6, F: 1.0). 3. The annual incidence increased from 1981 and was peaked in 1985. 4. The most commonly involvement site was the trunk(92%), the least common involvement(4%) was one of the face, neck, and shoulder combined. 5. The histopathologic findings in most patients shows focal vacuolization of the basal cell layer, pigment incontinence, dermal melanophages. 6. Electron microscopic findings of five patients consist of vauoles with abundant melanosomes in the basal cells, widened intercellular spaces and dermal melanophages.
Age of Onset ; Erythema* ; Extracellular Space ; Humans ; Incidence ; Melanosomes ; Neck ; Shoulder

Becker's nevus or Becker's melanosis is a distinct clinical entity in which epimal thickening may be minimal and hairiness and pigmentation obvious. 1Ne report a case of 14-year-old female suffering from Beckers melanosis with multiple and extensive skin lesions. The electron microscope revealed that the melanocytes were bulky with increased melanogenesis and an increased number of melanosomes was found in the keratinocytes. In addition, a large number of melanosomes were seen individually in the keratinocytes.
Adolescent ; Female ; Humans ; Keratinocytes ; Melanocytes ; Melanosis ; Melanosomes ; Nevus* ; Pigmentation ; Skin

Hypertrichosis is an overgrowth of hair not localized to the anclro en dependent areas of the skin. It may be congenital or acquired, localized or generalized localized hypertrichosis may occur in some types of pigrnentary nevi, chronic inflammation or irration, topical application of androgen or steroid, & localized myxedema. We report herein three i:ases of unilateral localized hypertrichosis with or without a brownish hyperpigmented patch developing on the face of a male adol scent. There are no known cau:,es of localized hyper trichosis. Histopath logically, it is characterized by increased melaniii pigment in the basal layer of the epidermis & enlarged hair follicles containing coarser liair. Electron microscopic findings show normal size & number of melanosomes in both mela nocytes & keratinocytes. Our cases differ frorn BecLers nevus in both clinical & histopatholcgic characteristics.
Epidermis ; Hair ; Hair Follicle ; Humans ; Hypertrichosis* ; Inflammation ; Keratinocytes ; Logic ; Male ; Melanosomes ; Myxedema ; Nevus ; Skin

Melanin is produced in melanocytes and stored in melanosomes. In spite of its beneficial sun-protective effect, abnormal accumulation of melanin results in esthetic problems. Hydroquinone, competing with tyrosine, is a major ingredient in topical pharmacological agents. However, frequent adverse reactions are amongst its major limitation. To solve this problem, several alternatives such as arbutin, kojic acid, aloesin, and 4-n-butyl resorcinol have been developed. Herein, we classify hypopigmenting agents according to their mechanism of action; a) regulation of enzyme, which is subdivided into three categories, i) regulation of transcription and maturation of tyrosinase, ii) inhibition of tyrosinase activity, and iii) post-transcriptional control of tyrosinase; b) inhibition of melanosome transfer, and c) additional mechanisms such as regulation of the melanocyte environment and antioxidant agents.
Arbutin ; Chromones ; Glucosides ; Hydroquinones ; Hypopigmentation ; Melanins ; Melanocytes ; Melanosomes ; Monophenol Monooxygenase ; Pyrones ; Resorcinols ; Tyrosine

We observed the clinical and histopathologic characteristics of acquired, bilateral nevus of Ota-like macules in each 80 and 23 patients. The results were as follows: 1. All patients were female and the peak age of onset was third decade with an a,verage age of 27.4 years. 2. The colors of lesions were slate, brown, dark brown, and blue black in order of freguency. 3. The lesions were most comrnonly observed in the malar area and alae nasi. 4. Three patients had family history of acquired, bilateral nevus of Ota-like :macules. 5. Histopathologically pigment-bearing cells, bipolar or irregular in shape, were found mostly in the upper- and mid-portion of the dermis. The melanocytes showed weakly positive dopa reaction. 6. In electron microscopic observation, these pigrnent-bearing cells contained many singly dispersed melanosomes in stage 3 and 4 of melanization and wece surrounded by an extracellular sheath.
Age of Onset ; Dermis ; Dihydroxyphenylalanine ; Female ; Humans ; Melanocytes ; Melanosomes ; Nevus of Ota* ; Nevus*

Penile melanosis is a new disease entity which is benign and different from pigmented nevus and acral lentiginous melanoma in situ. A 20-year-old man had hyperpigmented macules on the glans penis and penile shaft for 5 years. Clinical and histologic findings were consistent with penile melanosis and giant melanosome complexes were observed ultrastructurally.
Humans ; Male ; Melanocytes* ; Melanoma ; Melanosis* ; Melanosomes ; Nevus, Pigmented ; Penis ; Young Adult

Melatonin was derived from pineal gland, act as hormone and is known to be extremely active in certain biological systems. To observe the depigmentation effet of melatonin, author induced activation of melanocytes and melanin by UVB irradiation for seven days and then melatonin ointment or ointment base was applied topically on the ear skin of C57 B1 mouse. Tissue samples were obtained from 4 mice in each group before and after UVB irradiation for given days(1,3,5 and 7 week). The morphological, numerical, and ultrastructural changes of epidermal melanocytes were observed with light microscope and electron miroscope after DOPA stain. The results were as follows: 1) In all groups, the number of DOPA positive melanocytes began to decrease from 1 week. 2) The number of DOPA-positive melanocytes in melatonin ointment applied group was significantly lower than in control group. 3) In the electron microscopic findings, the number of melanosomes markedly decreased from 1 week to 7 weeks and a small amount of destructed melanosomes(vacuoles) and destroyed or swollen mitochondria in cytoplasm of th melanocyte appeared more significant in 3% melatonin ointment applied group compared to ointment base applied group from 5 weeks.
Animals ; Cytoplasm ; Dihydroxyphenylalanine ; Ear ; Melanins ; Melanocytes* ; Melanosomes ; Melatonin* ; Mice* ; Mitochondria ; Pineal Gland ; Skin