Investigation of hair shaft in seborrheic dermatitis using atomic force microscopy

Background/purpose: We have investigated the changes of seborrheic dermatitis (SD) on the hair shaft in the morphological and physical properties using atomic force microscopy (AFM). Methods: Hair samples were obtained from the lesional and perilesional regions in 15 patients with SD. Fifteen healthy adults were included as the control group. From the topography of hair obtained by AFM, the height of the scale, step height, roughness, diameter, and pit were determined. Results: The scale thickness of the SD‐affected hair was sevenfold more than in the control hair showing statistically significance. The lesional hair showed greater roughness parameters of S_a, S_q, and S_z than the perilesional and the control hair, but this difference was not significant. The cuticle of the lesional hair was significantly damaged while perilesional hair showed a very distinct cuticle structure with smooth edges and a regular interval between the cuticles. The diameter of the lesional hair was significantly lesser by 10–35% than that of the perilesional hair. The pit was rarely observed in the SD‐affected hair collected from both the lesional and perilesional regions. Conclusion: The changes in the hair shaft affected SD was measured using AFM non‐invasively. AFM could be a useful tool in monitoring the treatment response and the severity of SD.     

Efficacy of anti-aging products for periorbital wrinkles as measured by 3-D imaging

Background The periorbital area is a key wrinkle‐prone region, where the first signs of aging usually appear. Aims To demonstrate the ability of new anti‐aging moisturizing products to improve overall smoothness and wrinkle depth appearance in the periorbital region via the Fast Optical in vivo Topometry of Human Skin (FOITS). Methods Two double‐blind, randomized, controlled, split‐face studies (n = 42, Study 1; n = 35, Study 2) were conducted in women 30–70 years old with moderate to distinct periorbital wrinkles. Subjects applied 0.5 g of individual products to half their face twice daily for 4 weeks. Four test products containing niacinamide, the peptides Pal‐KT and Pal‐KTTKS, and carnosine were used and included a daytime SPF 30 lotion also containing antioxidants, a night cream, an eye cream also containing caffeine, and a wrinkle treatment containing retinyl propionate. The wrinkle treatment was only tested in Study 2. The FOITS technique was used to measure changes in periorbital R_a (mean roughness) and R_z (average maximum roughness) at 2 and 4 weeks. Results In Study 1, the daytime SPF 30 lotion, night cream, and eye cream significantly improved crow’s feet smoothness after 4 weeks relative to no treatment. After 4 weeks, the daytime SPF 30 lotion and night cream, but not the eye cream, were significantly better than no treatment at improving R_z. In Study 2, the night cream, eye cream, and wrinkle treatment, but not the daytime SPF 30 lotion, significantly improved both R_a and R_z after 4 weeks. To increase power and precision of estimates, a meta‐analysis was performed; the pooled data showed all three products were significantly better than no treatment at improving R_a and R_z after 4 weeks. Conclusions Four weeks of treatment with these products was shown to improve the smoothness of periorbital skin and to reduce the apparent depth of larger wrinkles.     

Genetic association of HLA-DQB1 and HLA-DRB1 polymorphisms with alopecia areata in the Italian population

Background Alopecia areata (AA) is a multifactorial disease characterized by hair loss especially from the scalp. As for other autoimmune conditions, the major histocompatibility complex (HLA) region is associated with AA susceptibility. Objective To provide evidence for the association of specific HLA‐DQB1 and HLA‐DRB1 alleles with AA in an Italian population, using a case–control approach. Methods We performed a case–control study to investigate whether HLA‐DQB1 and ‐DRB1 alleles predispose to AA in the Italian population. HLA class II typing was performed in 85 patients with AA and 210 healthy controls from the same ethnic group. Results An increased frequency of DQB1*03, coding for DQ7 heterodimers, and a decreased rate of the DQB1*06 allele were observed in patients when compared with controls; the greatest and significant difference was in the group of cases with a more severe phenotype [AA > 50% patients (more than 50% hair loss) vs. controls, P = 4·5 × 10^?3, P_c = 0·031, odds ratio (OR) 2·01, 95% confidence interval (CI) 1·22–3·31 and P = 2·5 × 10^?3, P_c = 0·017, OR 0·22, 95% CI 0·07–0·72, respectively]. DQB1*03, serologically related to DQ8 or coding for DQ9 molecules, was not associated with AA susceptibility. Out of all patients, 65·9% carried DQ7 heterodimers compared with 49·5% of the controls (P = 7·3 × 10^?3, OR 1·97, 95% CI 1·17–3·32) and DQ7 prevalence rose to 76·3% in patients with AA > 50% (P = 1·7 × 10^?3, OR 3·28, 95% CI 1·48–7·27). No significant difference was found in the distribution of DRB1 variants or phenotypes among cases and controls. Conclusion Our data show a correlation between the HLA‐DQB1 locus and the occurrence of AA in Italy supporting DQB1*03(DQ7) as a predisposing allele for the disease and the relevance of the HLA genetic test in the clinical management of AA.     

Refinement of the relative alkylation index (RAI) model for skin sensitization and application to mouse and guinea-pig test data for alkyl alkanesulphonates

Summary A derivation, more rigorous than hitherto, of the Relative Alkylation Index (RAI) as a quantifier of carrier protein haptenation in skin sensitization tests is presented. It is shown that the RAI, which is a composite parameter made up of dose, reactivity and lipophilicity terms, is likely to require a higher weighting for the reactivity term in the case of non-adjuvant tests than in the case of Freund's adjuvant-based tests. Methyl alkanesulphonates, RSO₃Me with R ranging from n-C₆H₁₃ to n-C₁₆H₃₃, were found to be skin sensitizers in a mouse ear swelling test, in agreement with published findings in a guinea-pig adjuvant model. A structure-activity relationship consistent with the published RAI model was observed whereby, in tests at fixed molar induction (0.1 mM) and challenge concentrations (0.025 mM), the level of sensitization response at first increased with increasing chain length of R, then showed a reversal of this trend at the highest chain length (R=n-C₁₆H₃₃). That this is a genuine overload effect, as reported for several other series of compounds examined in guinea-pig adjuvant models, is indicated by the finding that on reducing the induction concentration for the R=n-C₁₆H₃₃ compound the sensitization response was increased. Alkyl and alkenyl methanesulphonates, MeSO₃ R (R=n-C₁₂H₂₅, n-C₁₈H₃₇ and R=oleyl) did not give significant sensitization in the mouse ear test. Although they are chemically less reactive than methyl alkanesulphonates, these compounds are reported to be strong sensitizers in guinea-pig adjuvant tests and to fit a common quantitative sensitization — structure — dose relationship with the methyl alkanesulphonates. This difference between the murine and the guinea-pig adjuvant tests is attributed to the sensitization potential being more sensitive in the murine test to differences in chemical reactivity, as predicted by the more rigorously derived RAI model.Visiting Professor at the Université Louis Pasteur of Strasbourg, on leave of absence from Unilever, UK     

Indocyanine green-augmented diode laser treatment of port-wine stains: clinical and histological evidence for a new treatment option from a randomized controlled trial

Background Complete clearance of port‐wine stains (PWS) is difficult to achieve, mainly because of the resistance of small blood vessels to laser irradiation. Indocyanine green (ICG)‐augmented diode laser treatment (ICG+DL) may overcome this problem. Objectives To evaluate the feasibility of ICG+DL therapy of PWS and to compare the safety and efficacy of ICG+DL with the standard treatment, flashlamp‐pumped pulsed dye laser (FPDL). Methods In a prospective randomized controlled clinical study, 31 patients with PWS were treated with FPDL (λ_em = 585 nm, 6 J cm^?2, 0·45 ms pulse duration) and ICG+DL (λ_em = 810 nm, 20–50 J cm^?2, 10–25 ms pulse duration, ICG‐concentration: 2 mg kg^?1 body weight) in a split‐face modus in one single treatment setting that included histological examination (haematoxylin and eosin, CD34). Two blinded investigators and the patients assessed clearance rate, cosmetic appearance and side‐effects up to 3 months after treatment. Results ICG+DL therapy induced photocoagulation of medium and large blood vessels (> 20 μm diameter) but not of small blood vessels. According to the investigators’ assessment, clearance rates and cosmetic appearance were better after ICG+DL therapy than after FPDL treatment (P = 0·114, P = 0·291, respectively), although not up to a statistically significant level, whereas patients considered these parameters superior (P = 0·003, P = 0·006, respectively). On a 10‐point scale indicating pain during treatment, patients rated ICG+DL to be more painful (5·81 ± 2·12) than FPDL treatment (1·61 ± 1·84). Conclusion ICG+DL represents a new and promising treatment modality for PWS, but laser parameters and ICG concentration need to be further optimized.     

Interdependence between body surface area and ultraviolet B dose in vitamin D production: a randomized controlled trial

Background Ultraviolet (UV) B radiation increases serum vitamin D level expressed as 25‐hydroxyvitamin‐D₃ [25(OH)D], but the relationship to body surface area and UVB dose needs investigation. Objective To investigate the importance of body surface area and UVB dose on vitamin D production after UVB exposure. Methods We randomized 92 participants to have 6%, 12% or 24% of their skin exposed to 0·75 (7·5 mJ cm^?2 at 298 nm using the CIE erythema action spectrum), 1·5 (15 mJ cm^?2) or 3·0 (30 mJ cm^?2) standard erythema doses (SED) of UVB. Each participant underwent four UVB exposures at intervals of 2–3 days. Skin pigmentation and 25(OH)D levels were measured before and 48 h after the final exposure. Results The increase in 25(OH)D after irradiation [Δ25(OH)D] was positively correlated with body surface area (P = 0·006; R² = 0·08) and UVB dose (P < 0·0001; R² = 0·28), and negatively correlated with baseline 25(OH)D (P < 0·0001; R² = 0·18), for the entire data sample. However, when analysing each body surface area separately, we found a significant UVB response correlation for 6% (P < 0·0001; R² = 0·48) and 12% (P = 0·0004; R² = 0·35), but not for 24%. We also found a significant skin area response correlation for 0·75 SED (P < 0·0001; R² = 0·56), but not for 1·5 and 3·0 SED when analysing each UVB dose separately. The relationships did not change significantly after adjustment of Δ25(OH)D for baseline 25(OH)D. Conclusion The increase in 25(OH)D depends mainly on the UVB dose; however, for small UVB doses the area of irradiated body surface is important.     

Polyphenon E®: a new treatment for external anogenital warts

Background External genital warts (EGWs, condylomata acuminata) are a common, highly contagious disease caused by human papillomavirus (HPV), predominantly HPV 6 and HPV 11. Green tea catechins have been identified for their immunostimulatory, antiproliferative and antitumour properties. Two phase III trials evaluated treatment of EGWs with ointment containing a mixture of green tea catechins (Polyphenon E^®, U.S. adopted name: sinecatechins). Objectives To obtain additional data on the efficacy and safety of Polyphenon E^® ointment in the treatment of EGWs from two randomized, double‐blind, vehicle‐controlled trials. Methods Men and women aged ≥ 18 years (n = 1005), with two to 30 EGWs (12–600 mm² total area) applied vehicle (G_Veh; n = 207), Polyphenon E^® ointment 10% (G_10%; n = 401) or Polyphenon E^® ointment 15% (G_15%; n = 397) three times daily until complete clearance of all EGWs (baseline + new EGWs) or for a maximum of 16 weeks. Results A total of 1004 patients were evaluable for safety and 986 for efficacy; 838 completed treatment after 16 weeks. Complete clearance of all EGWs was obtained in 53·6% (G_10%) and 54·9% (G_15%) of patients with Polyphenon E^® vs. vehicle (35·4%) (P < 0·001). Statistically significant differences in clearance rates appeared after 6 weeks of active treatment. Odds ratios vs. G_Veh for G_10% [2·10; 95% confidence interval (CI) 1·49–2·98] and G_15% (2·22; 95% CI 1·57–3·14) indicated about a twofold higher chance of complete clearance under active treatment. Time to complete clearance was shorter with active treatment (hazard ratios 1·57 and 1·87, respectively, for G_10% and G_15% vs. G_Veh groups; P < 0·001). Recurrence rates during follow‐up were low and similar across groups: 5·8%, 6·8% and 6·5% (G_Veh, G_10% and G_15% groups, respectively). Adverse events were evenly distributed across groups (～ 30% of patients). Severe local signs were more frequent but moderate in the active treatment groups (1·5%, 9·2% and 13·5% for G_Veh, G_10% and G_15% groups, respectively). Conclusions Polyphenon E^® ointment is effective and well tolerated in the treatment of EGWs.     

Autoradiographische bestimmung der generationszeit der keratinocyten im stratum basale des ohrepithels verschieden alter ratten

Zusammenfassung An 46 männlichen Sprague Dawley-Ratten wurden in drei verschiedenen Altersstufen (2–4 Wochen alte juvenile, 2–4 Monate alte eben ausgewachsene und 2–2,5 Jahre alte senile Tiere) die mittlere Proliferationsrate und die mittlere Generationszeit (T _c) im stratum basale des Ohrepithels bestimmt. Dazu wurde den Versuchstieren während verschieden langer Zeiten³H-Thymidin über die Schwanzvene infundiert und anschließend autoradiographisch der Markierungs-index (Prozentsatz markierter Zellkerne) in der Basalzellschicht in Abhängigkeit von der Infusionsdauer bestimmt. Es zeigt sich, daß im stratum basale juveniler Ratten pro Stunde zusätzlich 0,461% neuer Zellen, bei den eben ausgewachsenen Tieren 0,306% und bei den senilen Ratten 0,288% gebildet werden. Entsprechend ergab sich, daßT _cbei juvenilen Tieren 7–8 Tage, bei eben ausgewachsenen und bei senilen Ratten 12–13 Tage lang ist. Damit besteht eine deutliche Altersabhängigkeit der Proliferationsrate und derT _c, wobei bemerkenswert ist, daß vom Erwachsenenalter bis ins Senium die Proliferationsabläufe im Wechselgewebe des Ohrepithels nahezu gleich bleiben.Wegen des Fehlens von nicht-markierten Mitosefiguren nach langdauernden Infusionszeiten haben wir keinen Anhalt dafür, daß die von Gelfant (1966) im Ohrepithel der Maus aufgefundene, langlebige G₂-Fraktion im Ohrepithel der Ratte vorkommt.

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Autoradiographic investigation in the generation time of the keratinocytes in rat ear epidermis at different stages of age

Summary In 46 male Sprague Dawley rats at different stages of age (juvenile 2–4 weeks, young adult 2–4 months and senile 2–2.5 years old animals) we studied the mean rate of proliferation and the mean generation time (t _c) in the stratum basale of the ear epithel. The results have been obtained using the technique of continuous infusion of³H-thymidine from 0.5 up to 20 days.In the stratum basale of the juvenile rats 0.461% of the cells were labelled per hour, in the young adult 0.306% and in the senile rats 0.288%. The corresponding values fort _cwere 7–8 days in juvenile, 12–13 days in young adult and in senile animals. Thus the rate of proliferation andt _cin the ear epithel of juvenile rats are depending on age. They remain constant from young adult to the senile rats.Even after long time of infusion we did not see non-labelled mitoses; therefore we could not justify the existence of a long-living G₂-fraction in the ear epithel of rats as Gelfant (1966) had found in mice.

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Mit Unterstützung durch die Deutsche Forschungsgemeinschaft.     

Intracellular free calcium and growth changes in single human keratinocytes in response to vitamin D and five 20-epi-analogues

Vitamin D, 1,25(OH)₂D₃, decreases proliferation and promotes differentiation of keratinocytes, and other keratinocyte differentiation stimuli have been associated with an early rise in intracellular free calcium, [Ca²⁺]_i. We therefore investigated the effect of 1,25(OH)₂D₃, its precursor D₃ and five 20-epi-analogues (EB1089, KH1060, KH1139, MC1288, MC1301) on growth and [Ca²⁺]_i levels of normal human keratinocytes. Cells were cultured in medium MCDB153 with an extracellular calcium concentration of 70 M or 1 mM. All the analogues were more potent than 1,25(OH)₂D₃ at inducing the morphological changes of differentiation, but D₃ was inactive. At concentrations down to 10^–8 M 1,25(OH)₂D₃, caused significant inhibition of growth, as assessed by counting cells and measurement of thymidine labelling. At 5 days 50% inhibition of growth occurred with 64 nM 1,25(OH)₂D₃ and 3330 nM D₃. All the analogues were more potent than 1,25(OH)₂D₃, and KH1060 inhibited growth at 10^–10 M. In single keratinocytes [Ca²⁺]_i was measured by micro-spectrofluorimetric techniques using the dye fura-2. No immediate rise in [Ca²⁺]_i was observed following addition of 1,25(OH)₂D₃ or the analogues up to 10^–6 M. However 10^–7 M 1,25(OH)₂D₃ or the analogues induced a gradual increase in [Ca²⁺]_i, significant at 4 h (P<0.001), which increased further over 2–3 days. D₃ had no effect on [Ca²⁺]_i. Increases in [Ca²⁺]_i following the differentiation stimuli of either 2 mM extracellular calcium or 1,25(OH)₂D₃ were similar at 48 h, increasing from 100 ± 3 nM (mean ± SEM) in control cells to 150 ± 3 nM with 2 mM calcium and 144 ± 6 nM with 10^–7 M 1,25(OH)₂D₃. The effect of extracellular calcium in raising [Ca²⁺]_i within minutes was more rapid than 1,25(OH)₂D₃, but in combination the two were not additive.     

Assessment of collagen lattice thickness by B-scan echography

Background/aims: Collagen lattices are an in vitro dermal equivalent that has led to the development of an original model of dermal tissue. Fibroblasts cultured in three-dimensions in a collagen matrix differentiate similarly to in vivo. New technological performances in ultrasonic imaging can now provide precise measurements of tissue thickness with good resolution. The aim of this study was to assess, by B-scan echography, the correlation between collagen lattice thickness and various collagen and cell concentrations. Methods: Three concentrations of human dermal fibroblasts (F₁ = 8.10⁵ C/mL, F₂ = 16.10⁵ C/mL, F₃ = 32.10⁵ C/mL) and three concentrations of rat tail collagen (C₁ = 2 mg mL⁻¹, C₂ = 3 mg mL⁻¹, C₃ = 4 mg mL⁻¹) were prepared for five different kinds of collagen lattices: F₂C₁, F₂C₂, F₂C₃, F₁C₁ and F₃C₁ (n = 5 per case). Ultrasonic imaging was performed on day 0, 4, 6, 10, 12 and 14 using a Dermcup^® 2020 scanner. The scans measured thickness in the centre and periphery of the lattice. Results: The collagen lattice echogenicity was similar to a dermis in vivo. For each assessment, the collagen lattice thickness increased until day 12 and then stabilized. The lattice was thicker when the cellular concentration was higher, (at day 14: F_1C1 = 0.66 mm, F_2C1 = 0.86 mm, F_3C1 = 1.21 mm). The collagen concentration did not significantly influence lattice thickness. Conclusion: Collagen lattice thickness increased with retraction time and cellular concentration.     

P2Y2R activation by nucleotides promotes skin wound‐healing process

P2Y₂R has been shown to be upregulated in a variety of tissues in response to stress or injury and to mediate tissue regeneration through its ability to activate multiple signalling pathways. This study aimed to investigate the role of P2Y₂R in the wound‐healing process and the mechanisms by which P2Y₂R activation promotes wound healing in fibroblasts. The role of P2Y₂R in skin wound healing was examined using a full‐thickness skin wound model in wildtype (WT) and P2Y₂R^?/? mice and an in vitro scratch wound model in control or P2Y₂R siRNA‐transfected fibroblasts. WT mice showed significantly decreased wound size compared with P2Y₂R^?/? mice at day 14 post‐wounding, and immunohistochemical analysis showed that a proliferation marker Ki67 and extracellular matrix (ECM)‐related proteins VEGF, collagen I, fibronectin and α‐SMA were overexpressed in WT mice, which were reduced in P2Y₂R^?/? mice. Scratch‐wounded fibroblasts increased ATP release, which peaked at 5 min. In addition, scratch wounding increased the level of P2Y₂R mRNA. Activation of P2Y₂R by ATP or UTP enhanced proliferation and migration of fibroblasts in in vitro scratch wound assays and were blocked by P2Y₂R siRNA. Finally, ATP or UTP also increased the levels of ECM‐related proteins through the activation of P2Y₂R in fibroblasts. This study suggests that P2Y₂R may be a potential therapeutic target to promote wound healing in chronic wound diseases.     

US Prescription trends of antihistamines for atopic dermatitis, 2011‐2016

Antihistamine use for primary treatment of atopic dermatitis (AD) is not recommended, but current guidelines state that sedating antihistamines are favored over non‐sedating antihistamines for relief of burdensome pruritus. We analyzed the National Ambulatory Medical Care Survey data to compare use of antihistamines between dermatologists and non‐dermatologists. Overall, dermatologists are more likely to prescribe sedating than non‐sedating antihistamines when compared to non‐dermatologists (P < .001, δ_abs = 0.45). Patients under 21 years old (P = .03, δ_abs = 0.10) and Black patients (P < .001, δ_abs = 0.19) were also more likely to receive sedating antihistamines than non‐sedating antihistamines. These findings highlight the differential prescribing practices for atopic dermatitis among physicians.     

A Case of Tuberous Sclerosis with a Giant Angiofibroma

This is a case study of tuberous sclerosis with unusually large facial angiofibromas. The patient had other intense skin manifestations. Histological findings in the angiofibroma included large and glial-appearing cells specific for this disease. Karyotype analysis revealed a translocation of chromosome (12q^–, 15q⁺).     

The relation between sunscreen layer thickness and vitamin D production after ultraviolet B exposure: a randomized clinical trial

Background Sunscreens absorb ultraviolet B (UVB) and it is a major concern that sunscreen use may lead to vitamin D deficiency. Objectives To investigate the relation between the amount of sunscreen applied and the vitamin D serum level in humans after UVB exposure under controlled conditions. Methods Thirty‐seven healthy volunteers with fair skin types were randomized to receive an inorganic sunscreen with sun protection factor (SPF) 8 of 0 mg cm^?2, 0·5 mg cm^?2, 1 mg cm^?2, 1·5 mg cm^?2, or 2 mg cm^?2 thickness on the upper body, approximately 25% of the body area. Participants were irradiated with a fixed UVB dose of 3 standard erythema doses 20 min after sunscreen application. This procedure was repeated four times with a 2‐ to 3‐day interval. Blood samples were drawn before the first irradiation and 3 days after the last to determine the serum vitamin D level expressed as 25‐hydroxyvitamin D₃ [25(OH)D]. Results The vitamin D serum level increased in an exponential manner with decreasing thickness of sunscreen layer in response to UVB exposure. For all thicknesses of sunscreen, the level of 25(OH)D increased significantly after irradiation (P < 0·05), except for the group treated with 2 mg cm^?2, in which the increase in 25(OH)D was not statistically significant (P = 0·16). Conclusions Vitamin D production increases exponentially when thinner sunscreen layers than recommended are applied (< 2 mg cm^?2). When the amount of sunscreen and SPF advised by the World Health Organization are used, vitamin D production may be abolished. Re‐evaluation of sun‐protection strategies could be warranted.     

Evaluation of a method for measuring the sustainable rate of sebaceous wax ester secretion

Summary Sebaceous was ester secretion rates were measured in six subjects on six occasions each, using absorption into bentonite clay and analysis of the collected lipid by quantitative thin-layer chromatography. On each occasion eight samples were collected, four from the left and four from the right side of the forehead in four successive intervals. The first two intervals, which totaled 14 h, were intended to deplete the follicular reservoir of sebum so that a constant rate of absorption could be obtained during the third and fourth intervals, which were 3 h each. Thin-layer analysis of each sample was done in triplicate. The data were examined using analysis of variance techniques to determine the reproducibility of the measurement method and to identify possible sources of variability.The intraclass correlation coefficient (r ₁) for all 432 post-depletion determinations was 0.80. The reproducibility was considerably better for three of the subjects (r ₁=0.93) than for the other three (r ₁=0.75). Variability within the latter three subjects did not seem to be attributable to lack of reproducibility in the thinlayer analysis. Real biological variability also seems unlikely considering the holocrine mechanisms of sebum secretion. Therefore, the variability probably arises from non-representative collection of sebum into the bentonite absorbent.     

Melanin and facial skin fluorescence as markers of yellowish discoloration with aging

Background: Although one clinical sign of aging and/or photoaging is a yellowish discoloration of the facial skin, little is known about the cause of this change. In addition to the increase in the epidermal melanin content, it has been suggested that advanced glycation end products (AGEs), which are known to accumulate in photoaged skin, may affect this discoloration. Aim: The objective of this pilot study was to non‐invasively investigate the roles of melanin and AGEs in this yellowish discoloration of the facial skin. Methods: We examined the spectral reflectance at the cheek in 40 healthy Japanese women of various ages (mean age, 38.1 years) using a reflectance spectrophotometer and a spectrofluorimeter. The degree of yellowish tint was evaluated in terms of b^*. The amount of melanin in the skin was evaluated by calculating the melanin index (MI) A₆₄₀–A₆₇₀ [A_λ: log₁₀ (1/reflectance) at a wavelength of λ]. The amount of AGEs was roughly evaluated using the AGEs index, which is thought to linearly correlate with the amount of intrinsic fluorescence markers irrespective of the concentration of melanin and is defined as follows: AGEs index=I₅/SQR (I₁×I₂). In this equation, the intensities of reflectance are I₁ at an excitation wavelength of 335 nm, I₂ at an emission wavelength of 390 nm and I₅ at 390 nm under an excitation wavelength of 335 nm. Results: Both b^* and the AGEs index were significantly correlated with subject age (r=0.34, P<0.05 and r=0.68, P<0.0001, respectively). Significant correlations were also observed between MI and b^* (r=0.63, P<0.0001) and between the AGEs index and b^* (r=0.53, P<0.0005). However, no significant correlations were seen between MI and the AGEs index. Conclusion: The AGEs index does not appear to be influenced by the amount of melanin and may be utilized as an indicator of the amount of AGEs in the skin. AGEs are likely to play a role in the yellowish discoloration of skin with aging.     

Genetic analysis of three important genes in pigmentation and melanoma susceptibility: CDKN2A,MC1R and HERC2/OCA2

Please cite this paper as: Genetic analysis of three important genes in pigmentation and melanoma susceptibility: CDKN2A, MC1R and HERC2/OCA2. Experimental Dermatology 2010; 19 : 836–844. Abstract: The CDKN2A gene is regarded as the major familial malignant melanoma (MM) susceptibility gene. Human pigmentation is one of the main modulators of individual risk of developing MM. Therefore, the genes involved in the determination of skin colour and tanning response are potentially implicated in MM predisposition and may be useful predictors of MM risk in the general population. The human melanocortin‐1 receptor gene (MC1R) plays a crucial role in pigmentation and also appears to be important in MM. The OCA2 gene has emerged as a new and significant determinant of human iris colour variation. We present a case–control study in Spanish population including 390 consecutive patients with melanoma and 254 control subjects. Sequence analysis of the entire coding region and genotyping of 5 tag‐SNPs in the genomic region of MC1R was performed. We identified 27 variants, two reaching statistical significance [R160W (OR: 4.18, 95% CI: 1.24–14.04, P = 0.02) and D294H (OR: 3.10, 95% CI: 1.37–7.01, P = 0.01)] and we detected two novel non‐synonymous changes: V92L and T308M. Odds ratio for carrying two functional variants was 4.25 (95% CI: 2.30–7.84, P = 3.63 × 10^?6). Haplotypes of the entire MC1R region have been established, and we observed an enrichment of a rare European haplotype similar to African values carrying variants V92M and I155T. In addition, three potentially functional SNPs were selected in p16/CDKN2A and in the promoter region of OCA2/HERC2. Our data for CDKN2A gene did not reach statistically significant results for any of the two studied alleles. We found that the variant allele A > G of OCA2/HERC2 (rs12913832) was associated with pigmentation features: eye, hair and skin colour; P‐values = 1.8 × 10^?29, 9.2 × 10^?16, 1.1 × 10^?3, respectively, validating previous results.     

Quantitative evaluation of elderly skin based on digital image analysis

Background: The evaluation of the skin state when it is healthy at the time of examination, but predisposed to disease, is based solely on the subjective assessment of clinicians. This assessment may vary from moment to moment and from rater to rater. Purpose: We focused on skin texture and aimed to develop a new method to evaluate skin integrity of the elderly using a digital skin image, by verifying the reliability of the clinical evaluation of elderly skin image by specialists to create a ‘gold standard,’ and by analyzing a digital skin image to identify the indices that explain the skin condition as evaluated by specialists. Methods: A total of 208 skin images were collected from 34 subjects. And then we processed and analyzed images. Modified Kobayashi's method and texture analysis method were used in image analysis. Kobayashi's method included the process of density transformation, cross binarization, short straight line matching and extraction of main sulcus, and calculation of each index. Texture analysis was performed on cross‐binarized images for quantification of uniformity. On the other hand, skin textures in images were scored by six plastic surgeons, using a 10‐point Likert scale, where 1 represented ‘very bad regularity’ and 10 represented ‘very good regularity.’ The inter‐rater reliability was verified by means of the intraclass correlation coefficients (ICC). Finally, stepwise multiple regression analysis was used to extract useful indices; where the clinical evaluation of the physicians (gold standard) was considered to be a dependent variable, and indices obtained from digital skin image analysis to be independent variables. Results: The ICC of raters was 0.92 (95% confidence interval; 0.91–0.94) when including all raters, therefore the score of all raters was used. As a result of stepwise multiple regression, the index of interval (L), thickness (T_ave), energy 0°, and entropy 45° independently explained the clinician evaluation. R² in multiple regression equation was 0.59. Conclusions: It is shown that quantitative evaluation using skin images and their analysis is one method of determining skin integrity in the elderly. The indices to explain the clinical evaluation of specialists were defined and these indices were obtained simply by using a skin image.