Han-Uk Kim

Effect of xanthohumol on melanogenesis in B16 melanoma cells

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.

Suction device for epidermal grafting in vitiligo: employing a syringe and a manometer to provide an adequate negative pressure.

Background. Suction devices for epidermal grafting need a suction pump to provide a negative pressure. The authors have developed a suction device in which a syringe and a manometer are employed to provide a negative pressure. Objective. The purpose of this study was to evaluate the efficacy of our suction device in vitiligo patients. Methods. The suction device was used to obtain epidermal blisters from the donor site. A CO2 laser was employed to remove the depigmented epidermis. The blister roofs of the donor site were harvested and were placed onto the recipient area. Ten patients with stable vitiligo were treated by epidermal grafting. Results. Epidermal blisters were produced by suction in all patients. Also, all 10 patients regained repigmentation. Conclusion. Our suction blister device is simple and inexpensive to make, and it may become an alternative to the other suction devices.

Treatment of Angiofibromas in Tuberous Sclerosis Complex: The Effect of Topical Rapamycin and Concomitant Laser Therapy

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.

Saponified Evening Primrose Oil Reduces Melanogenesis in B16 Melanoma Cells and Reduces UV-Induced Skin Pigmentation in Humans

This study was conducted to determine whether saponified evening primrose oil (sap-EPO) has the potential for use as a whitening agent and to investigate its underlying mechanisms of action. In B16 melanoma cells, sap-EPO dose-dependently inhibited isobutylmethylxanthine-induced melanogenesis with no cytotoxicity. This decrease in melanin production was correlated with reduced enzyme activity and decreased mRNA and protein levels of tyrosinase. The mRNA levels of tyrosinase-related proteins 1 and 2 decreased in response to treatment with sap-EPO, indicating that it regulated tyrosinase at the transcriptional level. Expression of microphthalmia-associated transcription factor was also decreased by sap-EPO as evidenced by decreased mRNA and protein levels. Additionally, topical application of sap-EPO resulted in efficient whitening of UVB-induced hyperpigmentation of human skin. Taken together, these results suggest that sap-EPO has the potential for use as a cosmetic whitening agent.

Squamous eddies in irritated seborrheic keratosis.

Seborrheic keratosis is related to the intraepidermal hair follicle in its morphogenesis. Squamous eddies in irritated seborrheic keratosis (ISK) are known to develop by focal maturation of basaloid cells, but the significance of squamous eddies is not understood. The purpose of this study was to elucidate the nature of squamous eddies in ISK. Serial sections of paraffin blocks of 20 cases of ISK were examined. We tracked each squamous eddy through the serial sections to observe the different shapes and positions of the same squamous eddy. In 4 cases, squamous eddies revealed hair shafts at their centers in different sections. In 14 cases, squamous eddies contained acrotrichial canals. In 13 cases, squamous eddies were connected to keratotic invaginations we thought to be follicular infundibula. Eighteen of the 20 cases of ISK showed at least 1 of the morphological features of intraepidermal hair follicle structures. We have found that the squamous eddies of ISK are anatomically related to acrotrichia.

Basal cell carcinoma arising in a tattooed eyebrow.

Malignant skin tumors, including squamous cell carcinoma and malignant melanoma, have occurred in tattoos. Seven documented cases of basal cell carcinoma associated with tattoos have also been reported in the medical literature. We encountered a patient with basal cell carcinoma in a tattooed eyebrow. We report on this case as the eighth reported case of a patient with basal cell carcinoma arising in a tattooed area.

Basal Cell Carcinoma on the Pubic Area: Report of a Case and Review of 19 Korean Cases of BCC from Non-sun-exposed Areas.

Basal cell carcinoma (BCC) is one of the most commonly diagnosed malignant skin tumors and develops characteristically on sun-exposed areas, such as the head and neck. Ultraviolet light exposure is an important etiologic factor in BCCs, and BCCs arising from non-sun- exposed areas are, therefore, very rare. In particular, the axilla, nipple, the genital and perianal areas are not likely to be exposed to ultraviolet light; thus, if BCC develops in these areas, other predisposing factors should be considered. Herein, we report a case of BCC arising on the pubic area in a 70-year-old man. We also performed a survey of the literature and discussed the 19 cases of BCC from non-sun-exposed areas reported to date in Korea.

Clinical and histopathological characteristics of extra‐facial basal cell carcinoma: Analysis of 35 patients at the Chonbuk National University Hospital in Korea

Basal cell carcinoma (BCC) primarily develops in the head and neck region, with 74–83 per cent of BCC occurring in this region. Unfortunately, most published studies on BCC were conducted in Caucasian populations, and analytic data on extra‐facial BCC in Asian and Korean patients, in particular, are not readily available. Here, we report on a retrospective analysis of extra‐facial BCC in Korean patients. Thirty‐five patients (16 men, 19 women) diagnosed with extra‐facial BCC at Chonbuk National University Hospital between January 1981 and December 2008 were evaluated. Their average age was 62.3 years and most of the patients (11 of 35, 31%) were in their fifties. The relative tumour density (RTD) was the highest in the genitalia (0.769), followed by the axilla (0.481). Other regions such as the trunk, buttocks and upper and lower extremities exhibited a much lower RTD (average: 0.1). Histopathological examinations showed that 16 tumours were nodular (46%), eight were superficial (23%) and seven were mixed (20%). Additionally, potential predisposing factors were identified in seven cases. In five patients the use of Asian medicine, including acupuncture and herbal medication, was ascertained. To the best of our knowledge, the present study is the first to analyse the clinical and histopathological characteristics of extra‐facial BCC in Korean patients. Our results indicate that the incidence of extra‐facial BCC is higher in the axilla and genitalia than at other locations, although these sites are frequently overlooked during routine skin examinations.

Pattern Alopecia during Hormonal Anticancer Therapy in Patients with Breast Cancer

We report five cases of pattern alopecia in female patients who are undergoing hormonal anticancer therapy for the prevention of recurrence of breast cancer after surgery. Three patients demonstrated male pattern alopecia with receding frontal hairlines, and two patients demonstrated female pattern alopecia without receding hairlines. The detailed clinical history showed that the pattern alopecia of the patients developed after the full recovery of global hair loss of the entire scalp due to previous cytotoxic chemotherapy. All of the adjuvant hormonal anticancer drugs that were used in the patients are antiestrogenic agents, either aromatase inhibitors or selective estrogen receptor modulators. Considering androgen effect on the hair follicles of the fronto-parietal scalp, the androgen-estrogen imbalance caused by the drugs was thought to be the reason for the onset of pattern alopecia in the patients. In general, alopecia that develops during cytotoxic chemotherapy is well known to both physicians and patients; however, the diagnosis of pattern alopecia during hormonal anticancer therapy in breast cancer patients seems to be overlooked.

Facial wrinkles as a predictor of decreased renal function.

Aims:  Oxidative stress generated either by exogenous or endogenous sources can lead to progressive organ damage and skin ageing over a long period of time. Moreover, some dermatological signs are independent of chronological ageing, and may reflect the long‐term redox state of internal organs. Therefore, we hypothesized that there might be an association between facial wrinkles and decreased renal function, an oxidative stress‐related disease.