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Journal of the American Academy of Dermatology 07/2012; 67(1):157; author reply 157-8. · 3.99 Impact Factor
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Annals of Dermatology 02/2012; 24(1):99-100. · 0.53 Impact Factor
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Annals of Dermatology 02/2012; 24(1):109-11. · 0.53 Impact Factor
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ABSTRACT: Knowledge of the histopathology of melasma is a prerequisite for understanding its pathogenesis. However, the histopathological characteristics of male melasma are not well characterized.
We sought to investigate the histopathological characteristics of melasma in men compared with those of women with melasma and solar lentigo.
Biopsy specimens were obtained from both the lesional skin and the adjacent nonlesional skin in 8 men with melasma, 10 women with melasma, and 5 men and women each with solar lentigo. The samples were stained using Fontana-Masson and Verhoeff-van Gieson. Immunohistochemistry for melanocytes, the estrogen receptor, progesterone receptor, factor VIIIa-related antigen, stem cell factor, and c-kit was performed.
Increased vascularity was found in the lesion of male melasma. The lesion to nonlesion ratio of the vessel area was increased in male melasma compared with lentigo groups. In the lesion of male melasma, there was a significant increase of stem cell factor and c-kit expression. In addition, the lesion to nonlesion ratio of stem cell factor was increased in male melasma compared with female melasma and lentigo groups. The lesion to nonlesion ratio of c-kit was also increased in male melasma compared with lentigo groups.
This study did not include clinical data regarding social habits and was not confirmed by other molecular techniques.
The results suggest that chronic ultraviolet radiation associated with signaling of paracrine cytokines plays an important role in the mechanism associated with hyperpigmentation in male melasma.
Journal of the American Academy of Dermatology 01/2012; 66(4):642-9. · 3.99 Impact Factor
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ABSTRACT: Melasma is a common pigmentary disorder caused by abnormal melanin deposits within the skin. Hydroquinone (HQ) is presently the most popular depigmenting agent, however the treatment of melasma remains unsatisfactory, resulting in a need to evaluate new depigmenting agents.
The objective of this study was to assess, using standard methods and a novel technique, in vivo Reflectance Confocal Microscopy (RCM), the efficacy and safety of a new non-HQ bleaching agent Dermamelan® (Mesoestetic, Barcelona, Spain) in the treatment of melasma.
Ten women with melasma were enrolled in an open-label trial lasting four months. Patients were of Fitzpatrick skin types II-IV. A non-HQ depigmenting agent (Dermamelan) was applied once-daily for three months. Melasma Area and Severity Indices (MASI) were measured. Standard and UV-light photographs were taken and in vivo RCM, which detects pigmentary changes at a cellular level, was done. Evaluations were performed before treatment, on the first, second and third month of treatment and one month after treatment. Upon cessation of the trial, patients completed a questionnaire regarding efficacy and tolerance.
At baseline, RCM detected hyperpigmented keratinocytes in all patients, dendritic cells in 2/10 patients, and melanophages in 2/10 patients. Based on the MASI score, Dermamelan treatment improved melasma by 50 percent. This was confirmed by standard and UV-light photography. Maximum therapeutic effect was usually reached by one month of treatment and was maintained at one month following its completion. Interestingly Dermamelan treatment also induced a statistically significant decrease of pigmented epidermal keratinocytes as detected by RCM. Patients with melanophages on RCM at baseline had a poorer outcome, but not those with dendritic cells. Mild irritation was the only adverse event observed during treatment. The majority of patients were satisfied with the result.
This study suggests that Dermamelan produces significant rapid improvement of melasma at a clinical and cellular level and demonstrates the potential of RCM to monitor and possibly predict efficacy of a new depigmenting agent in the treatment of melasma.
Journal of drugs in dermatology: JDD 11/2011; 10(11):1260-4. · 1.57 Impact Factor
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Christine Chiavérini, Hee-Young Kang,
Laura Sillard,
Etienne Berard,
Patrick Niaudet,
Geneviève Guest,
Mathilde Cailliez,
Philippe Bahadoran,
Jean Philippe Lacour,
Robert Ballotti,
Jean Paul Ortonne
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ABSTRACT: BACKGROUND: Patients with infantile nephropathic cystinosis have progressive accumulation of cystine in tissues leading to delayed extrarenal complications. No simple tool is available to evaluate the level of body cystine accumulation. OBJECTIVE: We sought to determine the value of in vivo reflectance confocal microscopy of the skin in patients with infantile nephrogenic cystinosis. METHODS: Nine patients and control subjects were recruited for this study. Images were acquired by means of a near-infrared reflectance confocal laser scanning microscope. RESULTS: Scattered bright particles within the papillary dermis were observed in all patients but not in control subjects. The density of particles ranged from numerous (+++) to very few (+/-) and their distribution was heterogeneous. Electron microscopy confirmed that these particles corresponded to cystine crystal deposits within dermal fibroblasts. The density of cystine crystals within the dermis was greater in older patients, in patients with a high leukocyte cystine concentration, and with delayed cysteamine therapy. There was no correlation between the density of cystine deposits and renal disease or hypopigmentation but high levels of deposition occurred in association with extrarenal manifestations. LIMITATIONS: This is a preliminary study on a small sample of patients. Repeated examination and longer follow-up is necessary. CONCLUSION: In vivo reflectance confocal microscopy of the skin appears to be a noninvasive means of assessing body cystine accumulation in infantile cystinosis and could be used as a complementary marker of treatment response in addition to leukocyte cystine measurement.
Journal of the American Academy of Dermatology 09/2011; · 3.99 Impact Factor
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Archives of dermatology 09/2011; 147(9):1106-8. · 4.76 Impact Factor
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Dermatologic Surgery 07/2011; 37(10):1519-24. · 1.80 Impact Factor
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ABSTRACT: Melasma is a commonly acquired hyperpigmentary disorder of the face, but its pathogenesis is poorly understood and its treatment remains challenging. We conducted a comparative histological study on lesional and perilesional normal skin to clarify the histological nature of melasma. Significantly, higher amounts of melanin and of melanogenesis-associated proteins were observed in the epidermis of lesional skin, and the mRNA level of tyrosinase-related protein 1 was higher in lesional skin, indicating regulation at the mRNA level. However, melanocyte numbers were comparable between lesional and perilesional skin. A transcriptomic study was undertaken to identify genes involved in the pathology of melasma. A total of 279 genes were found to be differentially expressed in lesional and perilesional skin. As was expected, the mRNA levels of a number of known melanogenesis-associated genes, such as tyrosinase, were found to be elevated in lesional skin. Bioinformatics analysis revealed that the most lipid metabolism-associated genes were downregulated in lesional skin, and this finding was supported by an impaired barrier function in melasma. Interestingly, a subset of Wnt signaling modulators, including Wnt inhibitory factor 1, secreted frizzled-related protein 2, and Wnt5a, were also found to be upregulated in lesional skin. Immunohistochemistry confirmed the higher expression of these factors in melasma lesions.
Journal of Investigative Dermatology 05/2011; 131(8):1692-700. · 6.31 Impact Factor
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ABSTRACT: Bacteria associated with marine invertebrates are a rich source of bioactive metabolites.
The effects of marine bacteria extracts on pigmentation were investigated to find novel whitening agents.
The marine bacteria collected near Gangwha Island in Korea were isolated and extracted using organic solvent. The organic extracts were screened and selected using the cell free tyrosinase activity. The whitening effects of the selected extract were further investigated using cultured melanocytes, cultured skin and in vivo zebrafish. The whitening mechanism of the marine extract was also investigated.
The marine bacterial methylene chloride extract reduced the pigmentation of Melan-a cells, human melanocytes, cultured skin and in vivo zebrafish. The decrease in pigmentation was due to the inhibition of tyrosinase activity and the expression of tyrosinase and microphthalmia-associated transcription factor protein. These bacteria were identified as a novel Pseudomonas species.
The methylene chloride extract of marine pseudomonas species possesses a whitening effect. Further chemical isolation and characterization of the active compounds from this marine bacterial extract are needed.
Annals of Dermatology 05/2011; 23(2):144-9. · 0.53 Impact Factor
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Journal of the American Academy of Dermatology 11/2010; 63(5):e97-100. · 3.99 Impact Factor
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ABSTRACT: Melasma is a common acquired hyperpigmentary skin disorder characterized by light to dark brown macules and patches occurring in the sun-exposed areas of the face. Melasma lesional skin is characterized by epidermal hyperpigmentation through increased melanogenesis in epidermal melanocytes. Some patients have dermal melanin but its amount is not significant and its distribution is very heterogeneous in the whole melasma lesional skin. Melasma is not homogeneous disease and there are personal characteristics of patients with melasma. The pathogenesis of melasma is not fully understood, but several hypotheses have been suggested. Increased vascularity in melasma lesions has suggested the role of increased number of enlarged vessels in the development of melasma. Endogeneous and exogeneous stimuli such as sex hormones and ultraviolet irradiation respectively may stimulate the microenvironment leading to the release of various mediators that cause activation of melanocytes and/or these stimuli may directly activate the melanocytes. Melasma patients may have specialized melanocytes with an intrinsic sensitivity to these stimuli.
Annals of Dermatology 11/2010; 22(4):373-8. · 0.53 Impact Factor
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ABSTRACT: Human melanocytes are not simply pigment-producing cells. It may be part of the inflammatory response, during which the pigmentary system may produce more melanin or suppress melanization. Toll-like receptors (TLRs) have been implicated in both innate host defense against pathogens and inflammatory response. Therefore, it may be possible that activation of TLRs in melanocytes may play a role in the modulation of melanogenesis. In this study, we investigated whether normal human melanocytes expressed TLRs and analyzed pigmentation changes upon TLR stimulation. The expression of TLR1~10 mRNA in cultured human melanocyte was analyzed using RT-PCR, Western blotting and immunocytochemistry. Human melanocytes constitutively express mRNA and protein for TLR2, 3, 4, 5, 7, 9 and 10. Stimulation of TLR1/2 and 4 with Pam3CSK4 and lipopolysaccharide induced pigmentation of melanocytes. Activation of TLR5 and 7 with flagellin and imiquimod treatments reduced pigmentation of melanocytes and zebrafish. In summary, the results provided evidence for TLRs expression in normal human melanocytes. It is speculated that a response of melanocyte to TLR ligands may play a role in the pigmentary change in the skin.
Annals of Dermatology 11/2010; 22(4):486-9. · 0.53 Impact Factor
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ABSTRACT: Melasma is a frequent pigmentary disorder caused by abnormal melanin deposits in the skin. In vivo reflectance confocal microscopy (RCM) is a repetitive imaging tool that provides real-time images of the skin at nearly histological resolution. As melanin is the strongest endogenous contrast in human skin, pigmentary disorders are the most suitable candidates for RCM examination but RCM features of melasma have never been reported. This study investigates the pilot use of RCM in melasma to provide a set of well-described morphological criteria with histological correlations. RCM images were acquired from melasma skin and compared to adjacent control skin in 26 patients. Skin biopsies were obtained from eight patients. In the epidermis, RCM showed in all patients a significant increase in hyperrefractile cobblestoning cells. These cells corresponded to hyperpigmented basal keratinocytes in histology. In six patients, dendritic cells corresponding to activated melanocytes were also found in the epidermis. In the dermis, RCM identified in nine patients plump bright cells corresponding to melanophages. Interestingly, for a given patient, the topographic distribution of melanophages in melasma lesions was very heterogeneous. RCM also showed a significant increase in solar elastosis and blood vessels in the dermis. RCM is a non-invasive technique that detects pigmentary changes in melasma at a cellular level resolution. Therefore, RCM provides an innovative way to classify melasma by pigment changes.
Experimental Dermatology 05/2010; 19(8):e228-33. · 3.54 Impact Factor
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ABSTRACT: Development of vitiligo-like hypopigmentary lesions associated with topical imiquimod has been reported. We hypothesized that mode of action of imiquimod in melanocytes may include triggering of apoptosis resulted in loss of cells, which may be a possible mechanism of imiquimod-induced hypopigmentary lesions. Therefore, we investigated whether imiquimod induces apoptosis of human melanocytes and also whether it modulates expression of apoptosis-related molecules in human melanocytes. Imiquimod treatment induced apoptosis of melanocytes, which was observed by TUNEL assay and Hoechst 33258 staining. Imiquimod-induced apoptosis was further shown by measuring mitochondrial membrane potential in melanocytes. The apoptotic activity of imiquimod was associated with caspase-3, Bcl-2 and mitogen-activated protein kinase expression in melanocytes. These results indicated that imiquimod induces apoptosis of melanocytes. These findings may provide a clue to understand pathogenesis of imiquimod-induced vitiligo-like hypopigmentary lesions.
Archives for Dermatological Research 05/2010; 302(4):301-6. · 2.28 Impact Factor
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ABSTRACT: Psoriasis is a relatively common disorder in children and can be triggered by an upper respiratory tract infection. The aim of this study was to compare the clinical features of psoriasis in children and adult. In addition, we evaluated the relationship between anti-streptolysin O (ASO) titers and the clinical features of psoriasis. A total of 30 childhood psoriasis patients and 30 adult psoriasis patients were evaluated. Childhood psoriasis had a facial predominance when compared with the adult psoriasis. The childhood psoriasis patients with high ASO titers had guttate psoriasis more frequently than patients with normal ASO titers. In children with plaque-type psoriasis, psoriasis area and severity index score was increased in the high ASO titer group than normal ASO titer group. In conclusion, if the children with psoriasis show increased ASO titer, the physician should pay attention to the worsening of the psoriasis. Furthermore, early treatment of streptococcal infections might be beneficial in childhood psoriasis.
Archives for Dermatological Research 05/2010; 302(4):295-9. · 2.28 Impact Factor
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ABSTRACT: The histological findings associated with idiopathic guttate hypomelanosis (IGH) are hyperkeratosis, an atrophic epidermis, and flattened rete ridges. In addition, a decreased melanin content and reduced numbers of melanocytes are reported features. However, there are few recent studies that have been published on the histopathology of IGH and no comparative studies are available on the skin lesions and perilesional skin of patients with IGH.
The goals of this study were to identify the clinical and histopathological features of IGH and determine their correlation. We evaluated the clinical features and the histopathological differences between the skin lesions and the perilesional skin in patients with IGH.
A clinical survey was carried out on 47 patients with IGH. Specimens from skin lesions and perilesional skin were stained with hematoxylin-eosin, Fontana-Masson, MART-1, and NKI/beteb. We also studied the ultrastructure of four cases.
About 30% of the patients had their initial lesions prior to 20 years of age. The arm was the most commonly affected site (53%). Histologically, we found hyperkeratosis in 18 cases (38.3%), but epidermal atrophy was present in only five cases (10.6%), and flattened rete ridges in seven cases (14.9%) compared to the normal skin. Epidermal atrophy was more frequently found at nonsun-exposed areas. The IGH lesions demonstrated decreased melanin pigment and reduced numbers of melanocytes by NKI/beteb and MART-1. The ultrastructural evaluation showed degenerative melanocytes and decreased melanosomes. One specimen had normal melanocytes with decreased melanosomes.
Idiopathic guttate hypomelanosis is a disorder with multifactorial etiology; its pathogenesis may depend on various factors such as patient age and sun-exposure. Histopathologically, hyperkeratosis was frequently found; however, the other characteristic findings such as epidermal atrophy and flattened rete ridges were relatively rare.
International journal of dermatology 02/2010; 49(2):162-6. · 1.18 Impact Factor
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Archives of dermatology 01/2010; 146(1):81-6. · 4.76 Impact Factor
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ABSTRACT: In vivo reflectance confocal microscopy (RCM) is a non-invasive, repetitive imaging tool that provides real-time images at nearly cellular histological resolution. Application of this technology to skin imaging during the last decade has been a great advance in dermatology. As melanin is the strongest endogenous contrast in human skin, pigmentary disorders caused by abnormal amounts of melanin in the skin could be the most suitable candidates for RCM examination. This article reviewed the RCM applications in the characterization and management of pigmentary disorders. The application of RCM in pigmentary disorders has been expanded to describe hyper- and hypopigmentary disorders as well as pigmented skin tumors. The great advantages of non-invasive and repetitive examination of RCM may provide its usefulness not only in the diagnosis and management of pigmentary disorders, but also in researching pathogenesis of pigmentary disorders.
Experimental Dermatology 11/2009; 19(3):233-9. · 3.54 Impact Factor
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International journal of dermatology 09/2009; 48(8):909-10. · 1.18 Impact Factor
