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

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*

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

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

Cutis verticis gyrata is a morphologic term, typically occurring on the scalp, characterized by eleuated, folded convolutions of the scalp, which may be either secondary to local disease in the scalp, or primary(idiopathic) disease. This case report was a 33-year-old woman, teacher. A birth, the patient had a small, round, soft, convoluted mass on the right parietal scalp. The mass slowly enlarged in size with the same rate of body growth. Now, the lesion is 15*13cm in size, well demarcated, oval shaped, soft, convoluted mass with overlying normal skin colored or hyperpigmented macules. Light microscopic findings of the skin kesion showed deeper extension of the nevus cells into the dermis and subcutis, which presented as an intradermal nevus, Electron microscopy showed that the nevus cell had an indented nucleus and numerous mitochondrias and melanosomes in the cytoplasm.
Adult ; Cytoplasm ; Dermis ; Female ; Humans ; Melanosomes ; Microscopy, Electron ; Mitochondria ; Nevus ; Nevus, Intradermal* ; Parturition ; Rabeprazole ; Scalp ; Skin

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*

Pigmentation is induced by production of melanin in specialized organelles termed melanosomes and by transfer of these organelles from melanocytes to surrounding keratinocytes. The chemical basis of melanogenesis is relatively well known but the mechanism of melanosome transfer is not well studied. Various pigmentary disorders and cosmetic applications require the use of depigmenting agents. Currently available topical agents used for the reduction of pigmentation mainly include tyrosinase inhibitors and/or melanocyte-cytotoxic agents. Recently, several agents have been introduced to inhibit melanosome transfer from melanocytes to keratinocytes. However, an experimental model for melanosome transfer is not well established. In this study, a simple assay method using flow cytometry is described.
Cosmetics ; Flow Cytometry ; Keratinocytes ; Melanins ; Melanocytes ; Melanosomes ; Models, Theoretical ; Monophenol Monooxygenase ; Organelles ; Pigmentation

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

BACKGROUND: Recently, Q-switched lasers have been reported to be successful in treating Ota's nevus without scarring. Utilizing the principle of selective photothermolysis, the Alexandrite laser has been developed for dermal pigmented lesions and tattoos. OBJECTIVE: In this study, we evaluated the clinical, histopathological and ultrastructual effect of the Alexandrite laser in the tretment of Nevus of Ota. METHODS: Forty-seven patients with nevus of Ota were treated with energy densities ranging from 5.0 to 8.0 J/cm2 at a miriimum of 6 week intervals. Sequential skin biopsy specimens were processed for the light microscope with H&E and Fontana-Masson stains and the electron microscope. RESULTS: The average number of treatments were 2.8 per patient. After two treatment sessions, 93 % patients 26 to 75% imprivement was seen. After three treatments 50 to 95% improvement was seen. No patients had permanent textual changes or scarring. On light microscop most of the dendritic melanocytes in the upper dermis were not observed in biopsy specimens taken after clinical improvement. Electron microscopy revealed damaged melanosomes in the upper dermis immediately after irradiation. CONCLUSION: Treatment with the Alexandrite laser for nevus of Ota is considered to be a safe and effective method.
Biopsy ; Cicatrix ; Coloring Agents ; Dermis ; Humans ; Lasers, Solid-State* ; Melanocytes ; Melanosomes ; Microscopy, Electron ; Nevus of Ota* ; Skin