Interleukin-21 receptor signalling is not critically required for imiquimod-induced psoriasiform dermatitis in mice.

Psoriasis is largely mediated by interleukin (IL)-23/T helper (Th) 17 axis, and IL-21 is a pleiotropic cytokine expressed by Th17 cells. Despite previously reported possible pathogenic roles of IL-21 in human psoriasis, we found that IL-21 receptor (IL-21R) signalling was not crucial for imiquimod-induced psoriatic inflammation, using IL-21R-/- mice. The severity of imiquimod-induced psoriatic manifestation and pro-inflammatory Th17 cytokine levels, IL-17A-producing γδ T cells and CD4+ T cells, and in vitro IL-17A production by γδ T cells after IL-23 stimulation was comparable between wild-type and IL-21R-/- mice. Collectively, IL-21R signalling was not critically involved in IMQ-induced psoriatic inflammation despite an increased IL-21 expression in the IMQ-treated mouse skin. Our data may represent the significant differences between human psoriasis and murine psoriasis model, and further studies using other models will be required to elucidate the role of IL-21 in psoriasis pathogenesis.

Deconvolution of spectral power distribution of high-power laser diode arrays.

A novel method is proposed to predict the spectral power distributions (SPDs) of individual emitters in a high-power laser diode (LD) array. The proposed method deconvolutes the SPD of an LD array by taking into account the thermal cross-talk effect as well as the current competition effect. A complete analytical expression to deconvolute the SPD of an LD array is described. The expression contains four key parameters that are to be measured experimentally: (1) the normalized SPD of the central emitter, (2) the temperature coefficient of wavelength, (3) the current competition constant, and (4) the maximum power of the center emitter. The method is implemented with a commercial water-cooled high-power LD array. The SPD of the LD array predicted from the SPDs of individual emitters are compared with the experimentally measured SPD of the LD array. The results show excellent agreement in both shape and magnitude, which corroborates the validity of the proposed method.

A Retrospective Study of Methylprednisolone Mini-Pulse Therapy Combined with Narrow-Band UVB in Non-Segmental Vitiligo.

BACKGROUND: Systemic corticosteroids have been used to arrest the progression of vitiligo. However, side effects have been a constant issue. OBJECTIVE: We evaluated the clinical efficacy and side effect of oral methylprednisolone (MPD) mini-pulse therapy combined with narrow-band UVB (NBUVB) for adults with non-segmental vitiligo retrospectively. METHODS: 32 patients with extensive and/or spreading vitiligo received 0.5 mg/kg MPD on 2 consecutive days per week with NBUVB therapy for at least 3 months. RESULTS: All of the 32 patients (100%) showed progression arrest within 12 weeks. Nineteen out of 32 patients (59.4%) presented repigmentation on more than 25% of lesions. Thirteen patients (40.6%) achieved satisfactory repigmentation in more than 50% of lesions. Only 2 patients discontinued the medication due to gastrointestinal trouble. CONCLUSION: Oral MPD mini-pulse therapy combined with NBUVB appears effective in arresting vitiligo progression and rapidly inducing repigmentation with minimal side effects.

Method for predicting junction temperature distribution in a high-power laser diode bar.

A hybrid experimental/numerical method is proposed for predicting the junction temperature distribution in a high-power laser diode (LD) bar with multiple emitters. A commercial water-cooled LD bar with multiple emitters is used to illustrate and validate the proposed method. A unique experimental setup is developed and implemented first to measure the average junction temperatures of the LD bar emitters. After measuring the heat dissipation of the LD bar, the effective heat transfer coefficient of the cooling system is determined inversely from the numerical simulation using the measured average junction temperature and the heat dissipation. The characterized heat dissipation and effective heat transfer coefficient are used to predict the junction temperature distribution over the LD bar numerically under high operating currents. The results are presented in conjunction with the wall-plug efficiency and the center wavelength shift.

Clinical features of psoriatic arthritis in Korean patients with psoriasis: a cross-sectional observational study of 196 patients with psoriasis using psoriatic arthritis screening questionnaires.

The prevalence and clinical features of psoriatic arthritis (PsA) in psoriasis patients vary widely in different countries, and studies on Korean population are rarely reported. The aim of this study was to investigate the clinical features of PsA in a Korean population of patients with psoriasis by using psoriatic arthritis screening questionnaires. A cross-sectional observational study was conducted, and consecutive psoriatic patients were evaluated for PsA by using two kinds of psoriatic arthritis screening questionnaires: Psoriatic Arthritis Screening and Evaluation tool (PASE) and Psoriasis Epidemiology Screening Tool (PEST). Psoriatic patients with higher score in screening questionnaires were referred to rheumatologist for confirmative diagnosis of PsA. Among 196 psoriasis patients screened by PASE and PEST, total prevalence of PsA was 11.2 % (n = 22/196) with 59.1 % of the cases being newly diagnosed. Compared with patients without PsA, patients with PsA had more extensive psoriasis, higher frequency of pustular and inverse type of psoriasis, and lower frequency of plaque type of psoriasis. Spondylitis was the most common manifestation pattern, followed by polyarthritis, oligoarthritis, predominant distal interphalangeal arthritis, and arthritis mutilans. Our findings are consistent with a low prevalence of PsA among patients with psoriasis in Asia. We also confirm a spondylitis as the most common pattern of PsA in Korea. PsA screening questionnaires can be a simple and useful tool to screen PsA in patients with psoriasis.

Metastatic melanomas of unknown primary show better prognosis than those of known primary: a systematic review and meta-analysis of observational studies.

BACKGROUND: Melanoma of unknown primary (MUP) is a condition of metastatic melanoma without a primary lesion. OBJECTIVE: We sought to identify the prognosis of MUP compared with melanoma of known primary (MKP). METHODS: We searched for observational studies containing at least 10 patients with MUP from MEDLINE and EMBASE from inception to December 22, 2012. The outcomes of interest were overall and disease-free survival; meta-analyses of hazard ratio stratified by stage using a random effects model were performed. In addition, second systematic review identified risk factors influencing the survival of patients with MUP. RESULTS: Eighteen studies including 2084 patients with MUP and 5894 with MKP were included. MUP had a better overall survival compared with MKP in stage III (15 studies; hazard ratio 0.83, 95% confidence interval 0.73-0.96, P = .010) and stage IV (6 studies; hazard ratio 0.85, 95% confidence interval 0.75-0.96, P = .008). Secondly, 22 studies including 3312 patients with MUP were reviewed, and increased stage and old age were the risk factors in patients with MUP. LIMITATIONS: Diverse observational studies were reviewed, and selection and reporting biases are possible. CONCLUSIONS: The current meta-analyses suggest better survival outcomes in patients with MUP than those in patients with MKP with the same corresponding tumor stage.

Preventive Effect of Human Acellular Dermal Matrix on Post-thyroidectomy Scars and Adhesions: A Randomized, Double-Blinded, Controlled Trial.

BACKGROUND: Acellular dermal matrix (ADM) has been used for antiadhesion formation along with wound healing in various surgical fields. OBJECTIVE: The aim is to assess the efficacy of ADM implantation in the prevention of postoperative scars and adhesions after conventional, open, total thyroidectomy. MATERIALS AND METHODS: Forty-four patients with papillary thyroid carcinoma undergoing thyroidectomy were randomly assigned to the study (ADM implantation) or control group (without ADM). Global photographic assessment, Vancouver scar scale (VSS), objective scar assessment, and swallowing impairment index were assessed at baseline, immediately after surgery, and at 1 and 2 months after surgery. RESULTS: Nineteen control and 20 study group participants completed the study. The mean VSS score of the study group was significantly lower than the controls at both 1 month (3.06 ± 1.25 vs 4.41 ± 1.54, respectively) and 2 months (2.76 ± 1.56 vs 4.35 ± 1.58, respectively) after surgery. Scar quality measures (mean melanin and erythema indexes) were significantly lower in the study group compared with controls. Study group participants had significantly lower swallowing impairment scores than controls. The mean postoperative hospitalization of both groups was not significantly different. CONCLUSION: Acellular dermal matrix-assisted implants appear to improve post-thyroidectomy scar and swallowing impairments without delays in operation time.

Red blood cell distribution width as a useful indicator to predict systemic vasculitis in patients with cutaneous vasculitis.

Cutaneous vasculitis can be limited to skin or a manifestation of primary systemic vasculitis. However, there are no definite markers to predict systemic involvements. Recent studies have shown that a higher red blood cell distribution width (RDW) is associated with disease activity in various disorders. We evaluated whether RDW can be used as an indicator for predicting systemic disease in patients with initial cutaneous involvements. We reviewed clinical and laboratory information of 143 patients with cutaneous vasculitis and 15 pigmented purpuric dermatosis patients seen at single academic hospital in Korea. Various parameters, including RDW, were evaluated in patients with primary cutaneous vasculitis and primary systemic vasculitis with initial cutaneous manifestations. The RDW value between cutaneous and systemic vasculitis patients was compared and RDW level was also investigated whether it can indicate systemic vasculitis in patients with cutaneous involvements. The mean age was 32.0 years, and 102 (64.6 %) patients were female. A total of 132 patients were patients with primary cutaneous vasculitis, and 11 were primary systemic vasculitis. Higher ratio of patients with high RDW was detected in systemic vasculitis group compared with cutaneous vasculitis group (36.4 vs. 7.6 %, P < 0.05). The mean RDW was significantly higher in systemic vasculitis patients (P < 0.05). RDW had the strongest association with systemic vasculitis (P < 0.05, OR 1.834). In conclusion, elevated level of RDW was significantly associated with systemic vasculitis. RDW can be used as one of the marker to predict systemic disease in patients with cutaneous vasculitis.

Skin-penetrating methotrexate alleviates imiquimod-induced psoriasiform dermatitis via decreasing IL-17-producing gamma delta T cells.

Accumulating evidence has shown that the Toll-like receptor 7 agonist imiquimod (IMQ) induces psoriasiform skin inflammation in mice and that this inflammation is dependent on the IL-23/IL-17 axis. Moreover, it has been demonstrated that the main source of IL-17 is not Th17 but is dermal gamma delta (γδ) T cells in mouse psoriasiform skin. Recent advances in the understanding of immunopathogenesis of psoriasis led to an alteration in the treatment paradigm to the use of highly efficacious biologics. However, their high cost impedes the extensive use of these agents. Thus, inexpensive and safe medications are still considered valuable. In this study, we introduce the therapeutic efficacy of a newly formulated methotrexate (MTX), a chemical conjugate of MTX with cell permeable peptide, for the treatment of psoriasis. Topically applied skin-penetrating (SP)-MTX reduced the psoriasiform skin phenomenon, epidermal thickness and infiltrating immune cells into the dermis. IL-17A-producing dermal γδ T cells in the cellular infiltrate that contribute IL-23/IL-17 axis were well abrogated by SP-MTX. Furthermore, SP-MTX had no toxic effects on liver, kidney or myeloid cells, unlike systemic administration of MTX. In conclusion, topically applied SP-MTX ameliorated psoriasiform skin inflammation in mice with the criteria of clinical phenomenon, histopathology and immunology, without inducing systemic toxic effects.

Altered vimentin protein expression in human dermal microvascular endothelial cells after ultraviolet or intense pulsed light treatment.

BACKGROUND: Endothelial cell senescence is closely related to tissue aging and age-related vascular disease. Detailed pathophysiology and essential biomarkers of skin aging are not well known. A recent report suggests that advanced glycosylation end products, especially N(ϵ) -(carboxymethyl)lysine (CML) modification of vimentin, accelerate the aging process. OBJECTIVES: To identify protein biomarkers of aging in skin. MATERIALS AND METHODS: Proteomics analysis was performed to identify differentially expressed proteins in human dermal microvascular endothelial cells (HDMEC) treated with ultraviolet (UV) or intense pulsed light (IPL). Proteome maps of UV-treated, IPL-treated, and untreated HDMEC were constructed, with identification of altered protein spots by matrix-assisted laser desorption/ionization mass spectrometry. Differential expression and glycation modification of vimentin were found by this approach and further examined by fluorescence-activated cell sorting. RESULTS: Twenty-two differentially expressed protein spots were identified. Among them, vimentin was specifically up-regulated in UV-treated HDMECs. On the other hand, it was down-regulated after IPL. Increased expression of CML-vimentin in HDMEC during culture (Passage 6 vs. 12) was noted, and this effect was reversed by IPL treatment. CONCLUSION: Vimentin and CML should be useful markers for cell senescence, as well as for evaluating the level of aging. Also, targeting increased vimentin expression and its advanced glycation end products could present a target for the treatment of skin aging.

Enhanced gas sensing performance of hydrophilic graphite nanoparticles synthesized by liquid phase pulsed laser ablation.

In this study, we firstly report that hydrophilic graphite nanoparticles were successfully synthesized by liquid phase pulsed laser ablation method and the carbon-polymer composite sensor prepared with the nanoparticles showed a markedly enhanced gas sensing performance. The pulsed laser ablation of graphite rod in water generated well dispersed hydrophilic graphite nanoparticle and they showed an extremely high stability in water without any surfactant or stabilizer. FT-IR spectra showed that the hydrophilic functional groups such as carboxyl and carbonyl groups were simultaneously introduced onto the surface of graphite with the nanoparticle formation and the highly negative zeta potential due to the functional groups was the origin of the markedly high stability in water. Finally, the carbon-polymer composite sensor composed of hydrophilic graphite nanoparticles and polyvinylpyrrolidone (PVP) demonstrated an enhanced detection response in comparison with the commercial carbon black, and which was attributed to the introduced hydrophilic functional groups on graphite nanoparticle surfaces.

Prevalence and severity of atopic dermatitis in Jeju Island: a cross-sectional study of 4,028 Korean elementary schoolchildren by physical examination utilizing the three-item severity score.

The objective of this study was to evaluate the precise prevalence of atopic dermatitis (AD) in schoolchildren in Jeju Island in South Korea examined in 2009. Nine elementary schools were randomly selected from Jeju Island and a total of 4,028 schoolchildren were examined by a dermatologist. AD was diagnosed based on the Korean Atopic Dermatitis Research Group criteria for the disease. The severity of AD was measured with the three-item severity score (TIS). The point prevalence of AD was 9.5% overall. The prevalence among higher graders (age 9-12 years) was significantly lower than that in lower graders (age 6-9 years) (7.5% vs. 11.9%, < 0.00001). AD prevalence in girls (11.1%) was higher than that in boys (8.1%) (<0.005). In each grade, more than 50% of those affected had the mild form (TIS score 1 or 2). There were no apparent differences in severity of AD between grades or genders. This is the first Asian study of prevalence in schoolchildren using TIS score for evaluating AD severity.