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*

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*

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

The present study was performed to evaluate the effect of sulfhydryl compounds, cysteine and glutathione, on the size of melanosomes and the ratio of melanosormai stages of epidermal melanocytes in UV-irradiated black mice. The results were as follows; 1. Both of cysteine and glutathione showed significant diminution in the short axis of melanosomes and the percentage of stage 4 melanosomes of epidermal melanocytes in C57BL black mice skin. 2. The length of short axis of melanosomes in glutathione-treated group is smaller than those in cysteine-treated group at the end of 3rd week of intraperitoneal injection. The percentage of stage IV melanosomes significantly decreased in glutathione-treated group and cysteine-treated group at the end of 3rd week and 5th week respectively. 3. In glutathione-treated group, the short axis of melanosomes and the percentage of stage 4 melanosomes both decreased in proportional to the period of intraperitoneal in]ection.
Animals ; Axis, Cervical Vertebra ; Cysteine ; Glutathione ; Injections, Intraperitoneal ; Melanocytes* ; Melanosomes ; Mice* ; Skin ; Sulfhydryl Compounds*

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

Aged ; Female ; Humans ; Male ; Melanosomes ; Metaplasia ; Middle Aged ; Nasopharynx ; cytology ; pathology ; Oxyphil Cells ; cytology

BACKGROUND: Nevus depigmentosus was first reported in 1884 by Lesser. It is defined as a congenital non-progressive hypopigmented macule or patch that is stable in its relative size and distribution throughout the life of the individual. The etiopathogenesis and histopathological characteristics of nevus depigmentosus are not fully established. OBJECT: The purpose of this study is to investigate the clinical and histopathological characteristics and pathogenesis of nevus depigmentosus. METHODS: Clinieal survey was carried out on forty-nine patients with nevus depigmentosus and two skin biopsies were taken from eighteen patients; from the central part of the depigmented lesion and the border of the lesion including the perilesional normal skin. The sections were stained with hematoxylin-eosin, Fontana-Masson and S-100 protein. The ultrastructural evaluation were also done to detect alternation of melanocytes. RESULTS: The results are as follows ; 1. The lesions were mostly (91.8%) present before the age of three, but some lesions appeared in childhood (8.2%). 2. The lesions were most frequently found on the trunk (42.9%), followed by the face and scalp (20.4%). 3. There were 33 patients (67.3%) with the isolated type, 15 patients (30.6%) with the dermatomal type and one patient with the whorled type. 4. Histopathological studies have shown that the stainability of Fontana-Masson in the lesions of nevus depigmentosus was decreased compared with perilesional nomal skin, but there were no changes in the number of melanocytes. 5. There was a great reduction in the number of melanosomes in melanocytes and keratinocytes of nevus depigmentosus. In keratinocytes, there was some aggregations of melanosomes and some of them showed membrane bound architecture. CONCLUSION: The results of this study support the fact that nevus depigmentosus is caused by functional defects of melanocytes and morphological abnonnalities of melanosomes.
Biopsy ; Humans ; Keratinocytes ; Melanocytes ; Melanosomes ; Membranes ; Nevus* ; S100 Proteins ; Scalp ; Skin

BACKGROUND: Transfer of melanosomes from melanocytes to the neighboring keratinocytes is a critical step in normal pigmentation. However, the mechanism of melanosome transfer and the regulation of pigmentation by the keratinocyte-melanocyte interactions are not well understood. It has recently been identified that keratinocytes use Foxn1 (transcription factor) to recruit melanocytes and induce their own pigmentation. OBJECTIVE: The purpose of this study was to assess the expression of Foxn1 in hypopigmentary disorders (vitiligo, pityriasis alba (P. alba) and postinflammatory hypopigmentation (PIHo)) and hyperpigmentary disorders (melasma, caf?-au-lait macule (CALM) and postinflammatory hyperpigmentation (PIHer)). METHODS: Immunohistochemical staining was performed on the formalin-fixed, paraffin-embedded tissue sections of hypopigmentary and hyperpigmentary disorders using anti-Foxn1 antibody with an avidin-biotin peroxidase complex procedure. The intraepidermal melanin pigments were examined in all the lesions by Fontana-Masson staining. RESULTS: We found a significantly lower Foxn1 expression (p<0.05) and less intraepidermal melanin pigments (p< 0.01) in the hypopigmentary disorders as compared to that of the hyperpigmentary disorders. In the hypopigmentary disorders such as vitiligo, P. alba and PIHo, the expression of Foxn1 was decreased in the order named. In thehyperpigmentary disorders such as CALM, PIHer and melasma, the expression of Foxn1 was increased in the order named. CONCLUSION: The intraepidermal Foxn1 expression and melanin pigments in PIHer, PIHo and melasma showed a positive correlation, but there was no statistically significant. Our findings suggest that the expression of Foxn1 might be associated with the pathogenesis of three pigment disorders (PIHo, PIHer, melasma). We consider that inflammatory mediators might interact with the intraepidermal Foxn1 expression in PIHo, PIHer and melasma, resulting in an abnormality of the mechanism of melanosome transfer. Further studies are warranted to elucidate the role of the Foxn1 expression in the pathogenesis of pigment disorders.
Hyperpigmentation ; Hypopigmentation ; Keratinocytes ; Melanins ; Melanocytes ; Melanosis ; Melanosomes ; Peroxidase ; Pigmentation ; Pityriasis ; Vitiligo