Xanthohumol (XH), the principal prenylflavonoid of the hop plant (Humulus lupulus L.), dose-dependently inhibited isobutylmethylxanthine (IBMX)-induced melanogenesis in B16 melanoma cells, with little cytotoxicity at the effective concentrations. Decreased melanin content was accompanied by reduced tyrosinase enzyme activity, protein and mRNA expression. The levels of tyrosinase-related protein 1 and 2 mRNAs were decreased by XH. XH also inhibited α-melanocyte stimulating hormone-or forskolin-induced increases in melanogenesis, suggesting an action on the cAMP-dependent melanogenic pathway. XH downregulated the protein and mRNA expression of microphthalmia-associated transcription factor (MITF), a master transcriptional regulator of key melanogenic enzymes. These results suggest that XH might act as a hypo-pigmenting agent through the downregulation of MITF in the cAMP-dependent melanogenic pathway.
Summary
Background
Tinea capitis (TC) is a dermatophyte infection involving hair and scalp and occurs primarily in prepubertal children. However, data on adults are limited.
Objectives
The aim of this study was to evaluate epidemiological, clinical and mycological characteristics of TC in adults in Korea.
Patients/Methods
We retrospectively evaluated 82 adults (44.3%) among 185 TC patients at a tertiary hospital during June 2000‐2017.
Results
Mean patient age was 66.9 ± 15.8 (20‐90) years with female predominance; mean disease duration until mycological diagnosis, 22.5 (1‐144) weeks; and misdiagnosis rate, 65.9%. Most common presumptive initial diagnoses were seborrhoeic dermatitis (24.4%) and bacterial folliculitis (18.3%). Chronic systemic illness and accompanying alopecia were found in 61 (74.4%) and 46 (56.1%) patients, respectively. Pustular type was found in 26.8% patients, followed by seborrhoeic dermatitis–like 25.6%, grey patch 23.2%, kerion celsi 22.0% and black dot 2.4%. Forty‐eight patients (58.5%) had tinea infection at other skin areas. Microsporum canis (56.5%) and Trichophyton rubrum (21.7%) were the most common causative organisms; 92.7% patients achieved complete resolution, and seven patients (9.2%) had a recurrence.
Conclusions
We report the largest, most recent series of case studies of adult TC. Adult TC is not an uncommon problem, especially in elderly women, and has distinctive epidemiological and clinicomycological characteristics compared to those in prepubertal children. Recognising adult TC profile will help clinicians avoid misdiagnosis and provide appropriate treatment.
Facial angiofibromas are the most troublesome cutaneous manifestations of the tuberous sclerosis complex and are difficult to treat. Lasers are most commonly used to treat these skin lesions, but results are disappointing with frequent recurrences. Recently, treatment of facial angiofibromas with topical rapamycin has been reported to yield promising results. We observed the need of laser ablation in addition to topical rapamycin to get best results for the treatment of angiofibromas in 4 cases. The result showed that topical rapamycin ointment was enough when the papules were yet small in size, i.e. less than a few millimeters, but additional laser ablation was needed for large papules approximately larger than 4 mm. Considering the natural course of facial angiofibromas, we believe that topical rapamycin can be best used in childhood patients. In adults, topical rapamycin was useful for treating the still present small papules and for preventing recurrences after laser treatment.
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