Relevance of the directionality of skin elasticity to aging and sagging of the face

Background: Forces acting in facial skin have been suggested to show directionality. Non‐invasive methods of measuring this directionality may thus provide information related to aging processes. The Reviscometer^® RVM600 device is capable of measuring directionality of forces on the skin. This device has not been used previously in a published study to evaluate changes in directionality of forces on facial skin with aging. Aim: The first objective of this pilot study was to investigate relationships between mechanical directionality using the Reviscometer^® RVM600, the Cutometer^® MPA580, and aging of the facial skin in a supine position. In addition, the study investigated relationships between mechanical directionality and ‘skin sagging,’ which may be caused by gravity. To validate this as a new measurement of mechanical directionality, we also performed double‐blinded trials on two groups of subjects, with one group using a product containing an anti‐aging substance and the other group using a placebo product without an anti‐aging substance. Methods: We examined 91 healthy Japanese women with a mean age of 48.5 years (range, 20–79 years) at the three sites on the face using the Reviscometer^® RVM600 and the Cutometer^® MPA580, and evaluation was performed for skin sagging in September and November 2008, and January 2009. The Reviscometer^® RVM600 was used to measure resonance‐running time (RRT) every 10° from 0° to 350°. Evaluation of skin sagging was undertaken by making marks on the face and using face photographs taken in both sitting and supine positions to calculate the sagging index. Usage testing was conducted on 38 healthy Japanese women in a double‐blinded study with one group, using a preparation containing Yomogi AGEs Clearing (YAC) extract and another group using the same preparation without the YAC extract from October 2008 to April 2009. Mean age of these subjects was 44.0 years (range, 30–60 years). Measurements were taken at the three sites on the face using the Reviscometer^® RVM600 and the Cutometer^® MPA580 and sagging index. Results: A significant correlation was identified between RRT parameters and subject age at all three measurement sites. Significant correlations between sagging index and RRT values were found for 110–170° and 290–350° only at the center of the cheek. Significant differences in RRT values were noted for 110–150° and 300–350° at this site between subjects with and without the use of YAC extract. A similar trend was found in sagging index for this site alone between subjects with and without YAC extract. Conclusion: The use of non‐invasive procedures to measure skin mechanical parameters on the face in all directions may evaluate aging and effective preventive and restorative support.     

Squamometry as a screening method for the evaluation of hydrating products

Background/aims: Squamometry is a combination of sampling corneocytes by adhesive coated discs followed by colour measurements after staining the cells. In this study, the correlation between stratum corneum (SC) hydration and scaling was investigated using capacitance measurements and squamometry, respectively. Methods: Stratum corneum hydration and assessment of barrier function by transepidermal water loss (TEWL) measurements were carried out on different sites of left and right volar forearm skin of female volunteers (n=13; 24±3 years). D-Squame^® samples were taken on the same test spots. Results: Visual evaluation of the coloured samples by light microscopy and the development of a four-point-scale scoring system was found to be necessary to detect and minimise overestimation of chroma C* values. Capacitance measurements revealed neither significant differences between corresponding sites on left and right forearms no between different skin areas on the same forearm. Squamometric measurements, on the contrary, did not show any symmetry between corresponding test sites on both forearms or between different sites on one forearm. No correlation could be found between squamometric measurements and SC hydration values obtained at the same test sites. No skin barrier function impairment lays at the origin of this observation since TEWL values were found to be similar at all test sites in comparison to control skin. In a randomised single blind study, hydration and TEWL showed a significant improvement of 25% and 15%, respectively, after a 14-day application period of a moisturising cream. Although visual scoring of the coloured samples of both treated and untreated test spots revealed a good correlation with chroma C* values, the quantitative results found with squamometry were very doubtful. Conclusion: Squamometry with visual scoring can be proposed as a screening technique for SC hydration rather than a quantitative method to appreciate skin moisturisation.     

Spatial variations in forearm skin tissue dielectric constant

Background: Tissue dielectric constant (TDC) values measured at 300 MHz via the open‐ended coaxial line reflection method depend on the effective measurement depth and the anatomical site being evaluated. Measurements on the forearm have shown that the TDC values decrease with increasing measurement depth but the spatial variability of the TDC values among forearm anatomical positions is unknown. Our goal was to characterize the extent of such spatial variations. Methods: In 30 healthy seated women (27.4±6.5 years), TDC was measured on the forearm midline and 1.2 cm medial and lateral to the midline at sites 4, 8 and 12 cm distal to the antecubital crease. Results: The midline and medial TDC values increased progressively from 4 to 8 to 12 cm sites (P<0.001), with the largest spatial gradient along the midline. At a depth of 2.5 mm, the TDC values increased from 26.3±2.8 to 27.4±3.4 to 28.4±3.7, with a maximum difference of 8.2±10.6%. For all sites, the TDC values were significantly (P<0.001) less for increasing depths. Conclusion: The findings reveal increased TDC values along the forearm from proximal to distal, most prominent at the midline and medial positions. Because many skin‐related dermatological and biophysical studies utilize the forearm as a test target, such differences may be important to consider because TDC values in part are reflective of local tissue water (LTW). Although the variation in the TDC values among sites was less than 10%, such differences are of importance when evaluating LTW changes using the TDC method in patients with arm lymphedema that is present in variable arm anatomical locations.     

Lack of correlation of skin thickness with bone density in patients receiving chronic glucocorticoid

Abstract The objective was to test the hypothesis that there is a correlation between thinning of the skin and bone in patients on chronic oral glucocorticoids (GCs). This was a one-time cross-sectional analysis performed in an academic referral center. The study group consisted of 14 patients on GCs for a variety of disorders, including dermatomyositis, pemphigus vulgaris, pyoderma gangrenosum, and urticarial vasculitis. Skin thickness was compared with that of 24 sex- and age-matched controls. The main outcome measures were the bone density of the lumbar spine (L2–L4) and the skin thickness. The skin thickness (mm, mean ± SEM) in GC-treated (n = 7) vs unmedicated age-matched Caucasian women (n = 20) was 0.84 ± 0.04 vs 1.02 ± 0.04 (t = 3.07, P < 0.01) in the upper arm, 1.13 ± 0.09 vs 1.49 ± 0.05 (t = 3.65, P < 0.002) in the dorsal forearm, and 0.96 ± 0.07 vs 1.17 ± 0.02 (t = 2.92, P < 0.01) in the ventral forearm. L2–L4 bone densities averaged 106 ± 2% in the GC-treated female patients relative to the age and sex-matched controls. There was no correlation between skin thickness and bone density. In GC-treated (n = 4) vs unmedicated Caucasian men matched for age (n = 4), skin thickness was 1.09 ± 0.4 vs 1.33 ± 0.05 (t = 3.51, P < 0.02) in the upper arm, but was not significantly different at the two forearm sites. No correlation between skin thickness and bone density was observed. The level of type I procollagen mRNA in skin from three GC-treated patients was 45% of the value in three age-matched controls. In conclusion, GCs cause statistically significant thinning of skin independently of the effects on bone. Received: 19 November 1997     

Effects of lotioned disposable handkerchiefs on skin barrier recovery after tape stripping

Background/purpose: In the present work, it was studied whether repeated use of lotioned disposable handkerchiefs on tape‐stripped forearm skin was able to improve skin barrier recovery. Methods: Skin assessments included scoring of visual erythema and dryness/scaliness; and measuring of skin redness (Chromameter^® CR300), skin hydration (Corneometer^® CM825), and transepidermal water loss (Tewameter^® TM300). Four different lotioned paper handkerchiefs – randomly assigned to one of two subject groups (n=20) – were tested vs. the non‐lotioned control handkerchief. The results were also compared with those obtained using a topically applied oil‐in‐water barrier cream (Dermalex^®). Results: The three‐day lasting protocol revealed that handkerchief wiping itself delayed skin recovery, but a significantly better performance was seen for the lotioned handkerchiefs containing fatty alcohols and mineral oils. This shows that the use of lotioned tissues helps to prevent skin damage inevitably caused by the wiping process. Conclusion: The controlled pre‐damaged forearm method with tape stripping appears to be a suitable model to study the effects of repetitive wiping on irritated skin with disposable handkerchiefs of different quality. More specifically, the model seems applicable to mimic the nasolabial skin damage observed during a common cold associated with frequent use of disposable handkerchiefs.     

Long-term efficacy and respective potencies of botulinum toxin A and B: a randomized, double-blind study

Background Mouse units (mU) are used for quantification of the biological activity of botulinum A and B toxin preparations. However, in human tissue, mU values between preparations are not equivalent and lack of clarity concerning efficacy and safety remains with regard to their respective potencies, duration of drug effect and diffusion qualities. Objectives To compare short‐term and long‐term effects of Botox^® (BOT; Allergan Inc., Irvine, CA, U.S.A.) and Neurobloc^®/Myobloc^® (NBC; Solstice Neurosciences Inc., Malvern, PA, U.S.A.) in different doses and dilutions in a human skin model. Methods In this prospective randomized double‐blind study, 18 healthy volunteers (eight women and 10 men; mean ± SD age 28·4 ± 5·7 years) were injected intradermally with pure saline, BOT and NBC at 10 points in the abdomen in random order, using the BOT/NBC conversion ratio 1 : 75 and different dilution schemes. For an objective outcome, the ninhydrin sweat test was used to compare the anhidrotic areas (action halos). Ten measurements were taken during a time period of 54 weeks. Results Both preparations showed a peak effect at week 3, with significantly larger anhidrotic areas for NBC. Thereafter, however, the rate of decline was lower in BOT and after week 24, mean BOT areas were larger. The effect of dilution was higher in NBC and the mean dose equivalence conversion ratio (BOT/NBC) was 1 : 29 (area under the curve). Gender effects were seen in both products, with smaller action halos in women. Conclusions These results have important implications in clinical routine, especially for autonomic indications.     

Skin fibroblast activity in pretibial myxoedema and the effect of octreotide (Sandostatin®) in vitro

The accumulation of glycosaminoglycans in the skin in pretibial myxoedema appears to be a response by local fibroblasts to a stimulating factor in the patient's serum, but the identity of the factor, its ability to stimulate skin fibroblasts as opposed to cultured thyroid cells, and the specificity of its effect to pretibial skin fibroblasts, are all controversial. We have studied fibroblasts cultured from the lesional skin of two women with pretibial myxoedema, and compared their proliferation and secretion of glycosaminoglycans with those of fibroblasts from the patients' forearms and from the forearm skin of two normal subjects. We found that in the presence of the patients' sera all six lines of fibroblasts secreted more glycosaminoglycans [205±21% (SD)] than with normal human sera (147±19%), or fetal calf serum (100%). Fibroblast proliferation showed the same pattern of differences: patients' sera 142±22%; normal human sera 116±9%, and fetal calf serum 100%. These experiments confirm the presence of a serum factor in pretibial myxoedema which is capable of stimulating the activity of skin fibroblasts in vitro, and show that its effects are not restricted to fibroblasts from pretibial skin or to those grown from the skin of the patients. Proliferation of normal fibroblasts cultured in medium supplemented with fetal calf serum was reduced by Sandostatin® (octreotide), but it failed to inhibit their secretion of glycosaminoglycans. In contrast, secretion of glycosaminoglycans by a patient's pretibial skin fibroblasts was almost completely inhibited by 1 mM minoxidil. In the presence of patients' sera Sandostatin® (0.1–10 μg/ml) reduced secretion of glycosaminoglycans by about 50%. Our data support the use of Sandostatin® in pretibial myxoedema, and suggest that it may suppress fibroblast glycosaminogly- can secretion within the skin via depletion of insulin-like growth factor or the blocking of its effect.     

In vitro antioxidant activity and in vivo efficacy of topical formulations containing vitamin C and its derivatives studied by non-invasive methods

Background/purpose: Vitamins C and its derivatives, mainly due to their antioxidant properties, are being used in cosmetic products to protect and to reduce the signs of ageing. However, there are no studies comparing the effects of vitamin C [ascorbic acid (AA)] and its derivatives, magnesium ascorbyl phosphate (MAP) and ascorbyl tetra‐isopalmitate (ATIP), when vehiculated in topical formulations, mainly using objective measurements, which are an important tool in clinical efficacy studies. Thus, the objective of this study was to determine the in vitro antioxidant activity of AA and its derivatives, MAP and ATIP, as well as their in vivo efficacy on human skin, when vehiculated in topical formulations. Methods: The study of antioxidant activity in vitro was performed with an aqueous and a lipid system. The in vivo methodology consisted of the application of these formulations on human volunteers' forearm skin and the analysis of the skin conditions after 4‐week period daily applications in terms of transepidermal water loss (TEWL), stratum corneum moisture content and viscoelasticity using a Tewameter^®, Corneometer^® and Cutometer^®, respectively. Results: In vitro experiments demonstrated that in an aqueous system, AA had the best antioxidant potential, and MAP was more effective than ATIP, whereas in the lipid system ATIP was more effective than MAP. In in vivo studies, all formulations enhanced stratum corneum moisture content after a 4‐week period daily applications when compared with baseline values; however, only the formulation containing AA caused alterations in TEWL values. The formulations containing MAP caused alterations in the viscoelastic‐to‐elastic ratio, which suggested its action in the deeper layers of the skin. Conclusion: AA and its derivates presented an in vitro antioxidant activity but AA had the best antioxidant effect. In in vivo efficacy studies, only the formulation containing AA caused alterations in TEWL values and the formulation containing MAP caused alterations in the viscoelastic‐to‐elastic ratio. This way, vitamin C derivatives did not present the same effects of AA on human skin; however, MAP showed other significant effect‐improving skin hydration, which is very important for the normal cutaneous metabolism and also to prevent skin alterations and early ageing.     

A novel in vivo model in guinea pigs for dry skin syndrome

Background/aims: The lack of a suitable, validated animal model for the comparison of the pharmacological effectiveness of known and potential moisturizers in the treatment of “dry skin syndrome” led us to develop such an in vivo model. Methods: “Dry skin syndrome” was induced in guinea pigs by daily application of 2% sodium lauryl sulphate (SLS) in deionized water on one of the two shaved flanks for three consecutive days. After ascertaining skin dryness, that side was treated with an agent for 6 days. The in vivo humectant effect was measured by a Corneometer CM 825^®, erythema was measured by a Mexameter MX 16^®. In some cases histological studies were carried out. Results: The treatment with the 2% SLS led to a consistent “dry skin syndrome” for 2 weeks. Glycerol, Vaseline, urea and ammonium lactate treatments validated the model, since the Corneometer CM 825^® readings of the treated dry side was equal to that of the control untreated side after 1 week of treatment. Mexameter MX 16^® measurements showed abolishment of the erythema by glycerol only. Histological study showed that SLS treatment creates acanthosis that is partially reversed by Vaseline and fully reversed by glycerol treatment. Conclusion: The guinea pig dry skin model is a relevant model of the human “dry skin syndrome”. The instrumental results combined with the histological findings indicate that erythema measurements are relevant for the determination of curative effect.     

A computerized analysis of intrinsic forces in the skin

The skin of the volar forearm is a site selected for many biometrological studies. We studied the influence of forearm position when evaluating the surface topography and mechanical properties of the skin in normal young adults. Optical profilometry of skin replicas and the suction biomechanical method (Cutometer ®, 2 and 8 mm probes) were used in combination with evaluation of the thickness and sliding mobility of the dermis and dermohypodermal tissues. The dermal and dermohypodermal thicknesses did not correlate with the various profilometric and biomechanical measurements. The surface topography and the axial sliding mobility of the skin were markedly influenced by forearm position, while the only mechanical property of the skin to be affected was skin stretchability assessed with the 2 mm probe. It is concluded that limb position mostly influences biometrological measurements made in the plane of the skin surface, while it has little effect on most of the Cutometer measurements.     

Reproducibility of laser Doppler imager flux measurements within ischemic or venous ulcers and adjacent skin

Background/aims: The laser Doppler imager (LDI) is a device that maps the local distribution of the laser Doppler flux of tissues. To facilitate the interpretation of LDI measurements, we investigated their reproducibility. Methods: We measured 10 arterial ulcers, 10 venous ulcers and their adjacent skin by the use of a LDI. The means were calculated of individual coefficients of variation ± standard error of mean (mean_CV±SEM) of measurements on the same day, on 5 different days and at specific time points (0, 30, 60, 90 and 120 min) during the application of PGE, on 2 different days. Results: The mean_CV±SEM of measurements on the same day were 9.3±0.9% (ulcer), 9.8±0.9% (skin), and on 5 different days they were 21.9±1.9% (ulcer) and 28.6±2.4% (skin). Ulcer measurements on 5 different days were significantly more reproducible than skin measurements, if differences were calculated for all 20 patients or for the 10 patients with venous ulcers separately (P<0.05). During the application of PGE, for 120 min, mean_CV±SEM ranged from 19.2±4.0% to 26.9±5.0% (ulcer) and from 20.5±4.1% to 29.5+3.9% (skin). CV of skin measurements of all 20 patients at 0 min were significantly lower than those after 120 min of PGE¹-application (P<0.05). Conclusion: Our results show an excellent reproducibility of LDI measurements on a single day. The reproducibility of measurements on 5 different days or during the application of PGE₁ over a period of 120 min was poorer. Because of the poorer reproducibility, more patients are needed to study long-term or drug effects.     

Clinical features of photodamaged human skin are associated with a reduction in collagen VII

Chronically sun-exposed or photodamaged human skin is characterized by a number of clinical features, including wrinkles. However, little is known about the molecular mechanisms that underlie these features. We investigated the hypothesis that the mechanism of wrinkle formation may involve loss of anchoring fibrils, composed mainly of collagen VII, which are important in maintaining dermal-epidermal junction integrity. Ten volunteers with moderate to severe photodamage of dorsal forearm skin were recruited to the study. Using immunohistochemistry, transmission electron microscopy and in situ hybridization, we compared collagen VII protein and mRNA content of photodamaged forearm skin with that of sun-protected hip and upper inner arm skin from the same subjects. Numbers of anchoring fibrils per linear μm of basement membrane (mean ± SEM) were significantly lower in photodamaged skin (1·79±0·10) as compared with sun-protected hip (2·28±0·11) and upper inner arm skin (2·21±0·10) (P<0·01), and similarly keratinocyte expression of collagen VII mRNA, quantitated as number of positively stained keratinocytes per high power field, was significantly reduced in photodamaged skin (6·3±2·5) as compared with sunprotected hip (20·0±5·6) and upper inner arm skin (17·7±4·9) (P<0·001). Semiquantitative assessment of immunohistochemical staining for collagen VII showed a non-significant reduction in photodamaged skin as compared with sun-protected skin. We propose that reduced content of collagen VII in photodamaged skin contributes to wrinkle formation by weakening the bond between the dermis and epidermis.     

Moisture Evaluator: a direct measure of fingertip skin hydration during object manipulation

Background/purpose: The mechanical properties of the fingertip skin are very important when studying dexterous manipulation. These properties are strongly influenced by the level of skin hydration. Currently, there is no device capable of measuring skin moisture during object manipulation. Methods: Skin moisture levels during object manipulation were measured using the Moisture Evaluator, a probe consisting of gold‐covered electrodes connected to a resistor–capacitor circuit. In vivo calibration was performed by comparison with measurements obtained using a Corneometer^® at two normal force levels (0.2 and 2 N). Results: Measurements from the Moisture Evaluator were well correlated with those from the Corneometer^®. Conclusion: A new device for evaluating skin moisture at the fingertip has been designed and validated.     

Plasma membrane fluidity of keratinocytes of normal and psoriatic skin: a study using fluorescence anisotropy of trimethylammoniumdiphenylhexatriene (TMA-DPH)

The aim of this study was to investigate plasma membrane fluidity in human keratinocytes using fluorescence anisotropy of 1,6-diphenyl-1,3,5-hexatriene (DPH) and its cationic derivative 1-[4-(trimethylamino)-phenyl]-6-phenyl-1,3,5-hexatriene (TMA-DPH). Keratinocytes from normal or psoriatic skin were isolated using trypsin-EDTA or dispase. In keratinocytes isolated from normal skin, TMA-DPH anisotropy values were higher than those observed using DPH; the difference must be related to the different localization of the two probes. In fact, DPH in whole cells localizes in plasma as well as intracellular membranes, yielding an average value of fluidity, while the cationic derivative TMA-DPH resides in the plasma membrane of the whole cells for a sufficient time for anisotropy measurements. Moreover, it has to be considered that plasma membrane is more ordered than intracellular membranes. The kinetics of incorporation of TMA-DPH was similar in keratinocytes isolated using trypsin-EDTA and those isolated using; dispase, however, the fluorescence anisotropy values were lower in keratinocytes isolated with dispase (0.260 ± 0.01 vs 0.270 ± 0.01, p = 0.029). This difference is probably related to modifications of lipid-protein interactions after trypsin treatment. Since no damage to plasma membrane after incubation with dispase seems to have been reported, we decided to use this separation procedure to study plasma membrane fluidity in psoriasis, a human pathological condition characterized by excessive cell proliferation and incomplete differentiation. Lower anisotropy values (0.260 ± 0.01 vs 0.270 ± 0.01, p = 0.001), indicating an increase in fluidity, were observed in keratinocytes isolated from skin of psoriatic patients than in epidermal cells isolated from normal human skin. We suggest that the measurement of fluorescence anisotropy in living cells is a convenient and useful tool to study membrane fluidity in human keratinocytes isolated from normal and diseased skin. Its application represents a technical advance because plasma membrane fluidity can be measured using very limited amounts of tissue, as obtained from biopsies. Received: 23 March 1995     

Decreased expression of filaggrin in atopic skin

The amounts of the epidermal proteins filaggrin, involucrin, cystatin A and Ted-H-1 antigen produced during the terminal differentiation of keratinocytes were immunohistochemically measured in lesional and nonlesional skin of atopic dermatitis (AD) patients. In addition, the amount of filaggrin in the skin of the inner surface of the upper arm of AD patients (nonlesional skin) and normal controls, obtained by punch biopsy, was measured by an enzyme-linked immunosorbent assay (ELISA) technique. The immunohistochemical study showed that all four proteins were decreased in lesional skin. By contrast, only filaggrin was decreased in nonlesional skin of AD patients. The ELISA showed that the amount of filaggrin in the skin of the inner surface of the upper arm was 2.48 ± 0.45 μg/7 mm ² ( n = 8) in AD patients, which was 32% of that in the normal controls (7.7 ± 0.55 μg/7 mm ² ; n = 4). This decrease in filaggrin production in atopic skin may be one of the reasons why atopic skin can easily become dry, because filaggrin is thought to be the precursor protein of the emollient factors in the stratum corneum. The evidence that only the expression of filaggrin was suppressed in AD patients, though the genes of filaggrin and involucrin are localized to a very restricted portion of the same gene 1q21, indicates that the filaggrin gene does not share regulatory elements with the involucrin gene. Received: 12 July 1995     

A closed unventilated chamber for the measurement of transepidermal water loss

Background/aims Open chamber systems for measuring transepidermal water loss (TEWL) have limitations related to ambient and body‐induced airflows near the probe, probe size, measurement sites and angles, and measurement range. The aim of the present investigation was to develop a closed chamber system for the TEWL measurement without significant blocking of normal evaporation through the skin. Additionally, in order to use the evaporimeter to measure evaporation rates through other biological and non‐biological specimens and in the field applications, a small portable, battery‐operated device was a design criteria. Methods A closed unventilated chamber (inner volume 2.0 cm³) was constructed. For the skin measurement, the chamber with one side open (open surface area 1.0 cm²) is placed on the skin. The skin application time was investigated at low and high evaporation rates in order to assess the blocking effect of the chamber on normal evaporation. From the rising linear part of the relative humidity (RH) in the chamber the slope was registered. The slope was calibrated into a TEWL value by evaporating water at different temperatures and measuring the water loss of heated samples with a laboratory scale. The closed chamber evaporation technique was compared with a conventional evaporimeter based on an open chamber method (DermaLab^®, Cortex Technology, Hadsund, Denmark). The reproducibility of the closed chamber method was measured with the water samples and with volar forearm and palm of the hand in 10 healthy volunteers. Results The skin application time varied between 7 and 9 s and the linear slope region between 3 and 5 s at the evaporation rates of 3–220 g/m² h. A correlation coefficient between the TEWL value from the closed chamber measurements and the readings of the laboratory scale was 0.99 (P < 0.001). The reproducibility of the evaporation measurements with the water samples was 4.0% at the evaporation rate of 40 g/m² h. A correlation coefficient of the TEWL values between the closed chamber and open chamber measurements was 0.99 (P < 0.001) in the range where the response of a conventional evaporimeter was linear (until 120 g/m² h). With volar forearm and palm of the hand of 10 healthy volunteers the reproducibility of the measurements was 8.0 and 10.1%. Conclusion The closed chamber technique solves the drawbacks related to open chamber evaporimeters. Especially, it extends the measurement range to high evaporation rates and TEWL measurements can be performed practically at any anatomical sites and measurement angle. By the use of a closed chamber the disturbance related to external or body‐induced air flows on the measurement can be avoided.     

Combined use of microfocused ultrasound and a calcium hydroxylapatite dermal filler for treating atrophic acne scars: A pilot study

Background: An unfortunate consequence of severe acne is scarring, which can have serious psychosocial consequences. Available methods for treating acne scars have varying degrees of effectiveness. Objective: This nonrandomized, retrospective pilot study assessed the safety and effectiveness of combining microfocused ultrasound with visualization (MFU-V; Ultherapy^®) and a calcium hydroxylapatite dermal filler (CaHA; Radiesse^®) for treating atrophic acne scars. Methods: Healthy subjects 35–55 years old with moderate-to-severe facial acne scars were enrolled. MFU-V was applied bilaterally using two transducers with focal depths of 3.0 and 1.5 mm. Using a cross-hatch pattern, 75 treatment lines were applied 2–3 mm apart. Immediately afterward, the same areas were injected with 1.5 mL of CaHA diluted with 1.5 mL of lidocaine 2% without epinephrine. Scar severity changes were assessed by two independent physicians using the Goodman Acne Scar Scale at post-treatment Day 90. Subject satisfaction was assessed with a questionnaire. Results: Treated subjects (N = 10) achieved significant overall improvement in baseline acne scar severity (P = 0.002). When stratified by severity, a clear trend was apparent with the greatest improvement observed among subjects with severe scars. Subjects were very satisfied (n = 9) or satisfied (n = 1) with their aesthetic results. No adverse events were observed. Conclusions: Combining MFU-V and diluted CaHA is effective for treating atrophic acne scars.     

The Visi-Chroma VC-100®: a new imaging colorimeter for dermatocosmetic research

Background/aims: It was the aim of this study to carry out a comparative evaluation in vitro on standardized color charts and in vivo on healthy subjects using the Visi‐Chroma VC‐100^®, a new imaging tristimulus colorimeter and the Minolta Chromameter CR‐200^® as a reference instrument. The Visi‐Chroma combines tristimulus color analysis with full color visualization of the skin area measured. The technical performances of both instruments were compared with the purpose of validating the use of this new imaging colorimeter in dermatocosmetic research. Methods: In vitro L*a*b* color parameters were taken with both instruments on standardized color charts (Macbeth and RAL charts) in order to evaluate accuracy, sensitivity range and repeatability. These measurements were completed by in vivo studies on different sites of human skin and studies of color changes induced by topical chemical agents on forearm skin. The accuracy, sensitivity range and repeatability of measurements of selected distances and surfaces in the measuring zone considered and specific color determinations of specific skin zones were also determined. Results: The technical performance of this imaging colorimeter was rather good, with low coefficients of variation for repeatability of in vitro and vivo color measurements. High positive correlations were established in vitro and in vivo over a wide range of color measurements. The imaging colorimeter was able to measure the L*a*b* color parameters of specific chosen parts of the skin area considered and to measure accurately selected distances and surfaces in the same skin site considered. Conclusion: These comparative measurements show that both instruments have very similar technical performances and that high levels of correlation were obtained in vitro and in vivo using the L*a*b* color parameters. In addition, the Visi‐Chroma presents the following improvements: 1) direct visualization and recording of the skin area considered with concomitant color measurements; 2) determination of the specific color parameters of skin areas chosen in the total measuring area; and 3) accurate determination of selected distances and surfaces in the same skin areas chosen.     

Distribution density of intraepidermal nerve fibers in normal human skin

A total of 74 specimens was obtained from the normal human skin of patients from 3 to 90 years old. The specimens were roughly classified into 5 groups: 15 for the face group from the face; 15 for the abdomen group from the abdomen; 13 for the back group from the back; 14 for the arm group from the upper arm and forearm; and 17 for the leg group from the thigh and lower leg. They were all fixed in 4% paraformaldehyde and 14% saturated picric acid. Cryostat sections were examined by the immunoperoxidase method and indirect immunofluorescence (IF). Primary antibodies against neurofilament, neuron-specific enolase, protein gene product 9.5 (PGP 9.5) and S-100 protein were used. The most effective method was found to be the combination of IF with PGP 9.5; it visualized the intraepidermal nerve fibers easily and clearly. Of the 74 specimens, 32 (43%) had intraepidermal PGP 9.5-immunoreactive (or nerve) fibers (IPIF), and 42 (57%) did not have any. With reference to the different skin locations, the maximal rate of specimens having IPIF was 57% in the arm group, and the minimum was 23% in the back group. IPIF positive specimens had approximate surface lengths of 6 mm, in which the existence number of the IPIF was 1 to 75. Their distribution density per 1000 epidermal basal cells was highest at 9.63 in the arm group and lowest at 2.89 in the back group. Their thickness was 2.94 +/- 0.83 microns with no significant differences among the five groups. We concluded that intraepidermal nerve fibers may not be distributed evenly in the hairy portions of normal human skin, but they may be present focally. Physiologically, two-point discrimination of itch may be explained by the distribution mode of intraepidermal nerve fibers.     

Cleansing lotion containing tamarind fruit pulp extract. II. Study of cumulative irritation effects in human

Background Cleansing lotion containing extract of tamarind fruit pulp was developed to provide skin a lighter effect. Skin irritation may occur due to keratolytic effect of α‐hydroxyl acids (AHA) in the tamarind fruit pulp extract. Objective To assess the cumulative irritation effect of cleansing lotion containing tamarind fruit extract with 2% (w/w) tartaric acid on human skin compared with placebo product and de‐ionized water. Methods The study design was a single‐blinded, randomized side of arm, and controlled study. Three samples, including test product, placebo product, and de‐ionized water, were repeatedly applied on the inner forearm of 15 healthy females (aged 28.3 ± 3.1 years) for 30 min daily for 5 days under semi‐occlusive patch. Skin irritation was measured by using visual scoring and instruments such as Tewameter® and Mexameter®. All measurements were done before application of samples every day from day 1 until day 5. Final measurements were done after the last application for 3 days (day 8). Results The results obtained from the visual scoring scale indicated no irritation signs and symptoms of test product. Mean differences of transepidermal water loss and erythema values between test product and de‐ionized water and between test and placebo products were not statistically significant (P > 0.05). Conclusions These findings indicate a preliminary safety evidence of our developed cleansing lotion containing the natural AHAs and can be used as cumulative evidence for supporting the future home use study of this product in human.