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Notes: Gynoid lipodystrophy (cellulite) is the irregular, dimpled skin surface of the thighs, abdomen, and buttocks in 85% of post-adolescent women. The distinctive surface morphology is believed to result when subcutaneous adipose tissue protrudes into the lower reticular dermis, thereby creating irregularities at the surface. The biomechanical properties of epidermal and dermal tissue may also influence severity. Cellulite-affected thigh sites were measured in 51 females with varying degrees of cellulite, in 11 non-cellulite controls, and in 10 male controls. A non-contact high-resolution three-dimensional (3D) laser surface scanner was used to quantify the skin surface morphology and determine specific roughness values. The scans were evaluated by experts and naїve judges (n = 62). Body composition was evaluated via dual-energy X-ray absorptiometry; dermal thickness and the dermal–subcutaneous junction were evaluated via high-resolution 3D ultrasound and surface photography under compression. Biomechanical properties were also measured. The roughness parameters Svm (mean depth of the lowest valleys) and Sdr (ratio between the roughness surface area and the area of the xy plane) were highly correlated to the expert image grades and, therefore, designated as the quantitative measures of cellulite severity. The strength of the correlations among naїve grades, expert grades, and roughness values confirmed that the data quantitatively evaluate the human perception of cellulite. Cellulite severity was correlated to BMI, thigh circumference, percent thigh fat, architecture of the dermal–subcutaneous border (ultrasound surface area, red-band SD from compressed images), compliance, and stiffness (negative correlation). Cellulite severity was predicted by the percent fat and the area of the dermal–subcutaneous border. The biomechanical properties did not significantly contribute to the prediction. Comparison of the parameters for females and males further suggests that percent thigh fat and surface area roughness deviation are the distinguishing features of cellulite.

Notes: Cultured skin substitutes have been used successfully for adjunctive treatment of excised burns and chronic skin wounds. However, limitations inherent to all models of cultured skin include deficient barrier function in vitro, and delayed keratinization after grafting in comparison to native skin autografts. Experimental conditions for incubation of skin substitutes were tested to stimulate barrier development before grafting, and measure responses in function and stability after grafting. Cultured skin substitutes consisted of human keratinocytes and fibroblasts attached to collagen-glycosaminoglycan biopolymer substrates. Parallel cultured skin substitutes were incubated at the air–liquid interface in ambient (48–61%) or saturated (79–91%) relative humidity, and grafted to athymic mice on culture day 14. Additional cultured skin substitutes were incubated in the experimental conditions for a total of 28 days. Cadaveric human skin and acellular biopolymer substrates served as controls. Epidermal barrier was evaluated as the change in surface hydration by surface electrical capacitance with the NOVA™ Dermal Phase Meter. Cultured skin substitutes and cadaveric skin incubated in ambient humidity had lower baseline surface electrical capacitance and less change in surface electrical capacitance than parallel samples incubated in saturated humidity at all time points in vitro. Data from healing cultured skin substitutes at 2, 4, 8 and 12 weeks after grafting showed an earlier return to hydration levels comparable to native human skin, and more stable engraftment for skin substitutes from ambient humidity. The data indicate that cultured skin substitutes in ambient humidity have lower surface electrical capacitance and greater stability in vitro, and that they reform epidermal barrier more rapidly after grafting than cultured skin substitutes in saturated humidity. These results suggest that restoration of functional epidermis by cultured skin substitutes is stimulated by incubation in reduced humidity in vitro.

Notes: Background/aims: The cutometer is an instrument that measures mechanical properties of skin. The NOVA dermal phase meter (DPM) measures the stratum corneum (SC) hydration level. The objectives of this study were to determine which parameters of the cutometer data curves were most sensitive to changes in SC hydration level, and to determine if lowering the skin stress applied by the cutometer would increase the instrument's sensitivity to SC hydration.Methods: In two studies, the volar forearms of ten and six subjects, respectively, were hydrated with wet paper towels for ten min. Measurements were made with the cutometer at various vacuum levels, and with the DPM. In another study, leg skin of nine subjects was hydrated by applying moisturizing lotions for 2 weeks. Measurements were made with the cutometer and DPM.Results/conclusion: Significant changes in DPM and cutometer measurements were found after hydrating skin in each study. However, only three correlations were found between cutometer data and DPM data. The lack of correlation was perhaps due to the differences in the depth into the skin which the two instruments measure. It is not clear which cutometer data parameters are generally most sensitive to hydration level, since different parameters were found to be most sensitive in each of the three studies. Finally, lowering the cutometer vacuum level generally did not increase the sensitivity of the measurements to changes in hydration levels.

Notes: Background/aims: Vernix caseosa is a proteolipid biofilm synthesized by the human fetus, which progressively covers the fetal skin surface during the last trimester of pregnancy. The exact physiological functions of vernix are unclear. Hypothetically, it serves a role in “waterproofing” the fetus during the critical period of epidermal barrier development before birth. Vernix may also play a role in adaptation of the fetal skin surface to the dry, cool extrauterine environment after birth. Given the strategic position of vernix on the fetal skin surface and the rapidly changing environment encountered by the skin at birth, we proposed that investigation of vernix surface characteristics would facilitate understanding its putative physiological roles.Methods: In this paper, we focused on the determination of the surface free energy (SFE) of vernix caseosa. Different approaches were used to calculate the SFE of vernix from contact angle (θ) measurements between vernix and various liquids (benzyl alcohol, diiodomethane, glycerol, and water). The critical surface tension (CST) of vernix was calculated using Zisman plots. The dispersive and the polar components of vernix SFE were calculated using the Owens–Wendt geometric mean method. Vernix was contrasted with petrolatum, a commonly used skin protectant.Results: CST of fresh vernix was 40.5 dyne/cm while that of petrolatum was 35.8 dyne/cm. Fresh vernix polar SFE was 1.5 dyne/cm while petrolatum had almost no polar SFE component (0.03 dyne/cm). For all liquids (except the nonpolar diiodomethane) there was a significant decrease in contact angle with time.Conclusions: The CST and the total SFE values suggest that vernix has very low surface energy and is highly unwettable. These findings are significant insofar as the main component in vernix is water, which is highly energetic. Although vernix has a very high water content, the major part of its SFE is hydrophobic (dispersive). The limited interaction between vernix and hydrophilic liquids supports the hypothesis that vernix acts as a natural protectant cream to “waterproof” the fetus in utero while submerged in the amniotic fluid.

Notes: The Dermal Torque Meter® (DTM) and the Cutometer® are instruments that measure mechanical properties of skin. The NOVA(tm) Dermal Phase Meter® (DPM) measures the stratum corneum (SC) hydration level. The objectives of this study were to determine which parameters of the DTM data curves were most sensitive to changes in SC hydration level, which of the two instruments (Cutometer or DTM) was most sensitive, and what correlations existed between the Cutometer and DTM data.〈section xml:id="abs1-2"〉〈title type="main"〉Methods: Dry leg skin was created on nine subjects by washing with soap and using no moisturizers for one week. The skin was then treated with moisturizing lotions for two weeks. Measurements were made with the Cutometer, DTM, and DPM pre- and post-treatment.〈section xml:id="abs1-3"〉〈title type="main"〉Results: Significant changes in DPM, DTM, and Cutometer measurements were found after the moisturizer treatment. However, correlations were not found between mechanical property data and DPM data. The DTM had the two parameters with the highest sensitivity of all of the DTM and Cutometer parameters. Finally, correlations between the two instruments existed for only three of the ten parameters investigated.〈section xml:id="abs1-4"〉〈title type="main"〉Conclusions: While measurements with all three instruments significantly changed in response to skin hydration, neither the DTM nor Cutometer data tended to correlate with DPM data, perhaps due to the differences in the depths into the skin which each instrument measures. Furthermore, the mechanical properties measured by the two instruments do not correlate well between the instruments. Finally, the DTM was found to have the most sensitive parameters.

Notes: Abstract:  Skin pigmentation results in part from the transfer of melanized melanosomes synthesized by melanocytes to neighboring keratinocytes. Plasma membrane lectins and their glycoconjugates expressed by these epidermal cells are critical molecules involved in this transfer process. In addition, the derivative of vitamin B3, niacinamide, can inhibit melanosome transfer and induce skin lightening. We investigated the effects of these molecules on the viability of melanocytes and keratinocytes and on the reversibility of melanosome-transfer inhibition induced by these agents using an in vitro melanocyte–keratinocyte coculture model system. While lectins and neoglycoproteins could induce apoptosis in a dose-dependent manner to melanocytes or keratinocytes in monoculture, similar dosages of the lectins, as opposed to neoglycoproteins, did not induce apoptosis to either cell type when treated in coculture. The dosages of lectins and niacinamide not affecting cell viability produced an inhibitory effect on melanosome transfer, when used either alone or together in cocultures of melanocytes–keratinocytes. Cocultures treated with lectins or niacinamide resumed normal melanosome transfer in 3 days after removal of the inhibitor, while cocultures treated with a combination of lectins and niacinamide demonstrated a lag in this recovery. Subsequently, we assessed the effect of niacinamide on facial hyperpigmented spots using a vehicle-controlled, split-faced design human clinical trial. Topical application of niacinamide resulted in a dose-dependent and reversible reduction in hyperpigmented lesions. These results suggest that lectins and niacinamide at concentrations that do not affect cell viability are reversible inhibitors of melanosome transfer.

Notes: "Theme: Spirituality and Religious Education"