bluuebunny/crossref_metadata_2025 huggingface dataset:
Epidermal thickness measured by light microscopy: a methodological study
Authors: Therkildsen Pia , Haedersdal Merete , Lock‐Andersen Jørgen , de Fine Olivarius Frederik , Poulsen Thomas , Wulf Hans Christian
Published: October 2006

Background/aims: Epidermal thickness is frequently measured by light microscopy. The preservation and staining methods may alter the proportions of the specimens and thereby influence the measurements. The aim of the present study was to describe: 1) a standardized light microscopic method to quantify the thicknesses of the stratum corneum and the cellular epidermal layers, 2) the variations according to preparation and staining techniques, and 3) the observer variability. Methods: One hundred and sixty skin biopsies from 67 human volunteers were included. The cellular epidermis and the stratum corneum were estimated in sections preserved by freezing and subsequent preparation with cryostat or formalin‐paraffin techniques. The slides were stained with haematoxylin‐eosin or er‐ythrocin, and thicknesses of the stratum corneum and the cellular epidermis were measured by a calibrated ruler and an ocular grid, respectively.

Results: The formalin fixation gave slightly higher values for the cellular epidermis than the cryostat technique. In comparison to erythrocin staining, haematoxylin‐eosin gave a significantly thinner stratum corneum. No significant inter‐ or intra‐observer variation was found for the thickness of the stratum corneum assessed twice by two experienced observers. However, the two observers differed slightly from each other on the thickness of the cellular epidermis.

Conclusion: It is found that thickness measurements of the stratum corneum and the cellular epidermis are reliably performed on cryostatic cut sections stained with haematoxylin‐eosin.
In vivo assessment of n‐alkyl‐sulfate‐induced skin irritation by means of non‐invasive methods
Authors: Nardo A. Di , Conti A. , Martini M. , Seidenari S.
Published: October 2006

Background/aims: Sodium lauryi sulfate (SLS) is the most frequently used model for studying in vivo irritation. It is also one of the most frequent surfactants in soap preparations and cosmetic emulsions. To investigate the irritant potential of sodium salts of n‐alkyl sulfates with different carbon chain length (n=8, 12, 14), we applied these substances on the volar forearm of 10 healthy human volunteers aged 24 to 35 years.

Methods: To allow the equal solubilization of the surfactants, we used a 0.2% solution (w/v). A colorimeter to assess erythema, an evaporimeter to assess transepidermal water loss (TEWL) and a corneometer to evaluate skin hydration were employed to estimate the effects of the chemicals on the skin. Evaluations were performed at baseline, 24, 48 and 72 h.

Results: TEWL had increased at 24 h: SLS showed the highest increase, followed by octyl and tetradecyl sulfate. Skin hydration was reduced for the three substances, and a slight increase in redness was noticed. TEWL and hydration values at different times of assessment enabled the ranking of n‐alkyl sulfates in the following order: lauryi sulfate, tetradecyl sulfate and octyl sulfate.

Conclusions: We could not prove a direct correlation between barrier impairment, skin dehydration and surfactant‐induced inflammation, as evaluated by color measurements. This discrepancy suggests that the irritation potential of n‐alkyl sulfates at the dermal level differs from their action on skin barrier.
Comparison of the efficacy and safety of three different depilatory methods
Authors: Bjerring Peter , Egekvist Henrik , Blake Thomas
Published: October 2006

Background/aims: Three methods of electrical energy‐based depilation were compared for safety and efficacy.

Methods: Ten volunteers had one treatment with each device followed by weekly observations up to 9 weeks. The protocol used was basically that of the International Guild of Professional Electrologists, which is used to define “permanent” hair removal.

Results: Radio frequency tweezers, direct current tweezers and needle based electrolysis all demonstrated statistically significant reductions in hair counts after 9 weeks of 60.3%, 65.8% and 55.9%, respectively. The differences between the treatments were not statistically significant. However, large differences in side effects and pain scores existed. Both tweezer type epilators induced pain rated at 13/100 on a visual analogue scale while the needle based depilator induced significant pain at 59/100. Furthermore, acute inflammation and late scarring was seen only following treatment with the electrolysis needle.

Conclusion: The tweezer‐type epilators are as effective as needle‐based electrolysis but without the pain and side effects of the latter.
The face and neck: regional variation in skin barrier function and reactivity
Authors: Leroy T. , Geveaux C. , Crucq J. , Douven L. F. A. , Neste D. Van
Published: October 2006

Background/aims: Although there are many reports of regional variations in skin response to various stimuli, only a few studies have been performed on the face. The forearm is the most often used test site while the face is a frequent and specific target of many topical agents (drugs and cosmetics) and cosmetic procedures. The aim of this study was to compare regional variations of cutaneous sensation and skin barrier function in the cheek, neck and forearm before and after application of different stimuli (physical and/or chemical).

Methods: Physiological changes of the skin were measured by non‐invasive methods: TEWL (transepidermal water loss) and skin capacitance. Furthermore, clinical scoring and subjective sensations were reported. The anatomical sites evaluated were cheek, neck and volar forearm.

Results: Great differences in clinical reactions, subjective sensations and skin barrier function in response to various stimuli have been observed between tested areas (cheek, neck and forearm). We observed a greater “sensitivity”, i.e., more severe clinical reactions and subjective sensations of the cheek and neck areas, in relation to chemical stimuli as compared to the forearm. After a mechanical stimulus, the forearm was the most sensitive site, but just for subjective sensations. Concerning skin barrier function, the cheeks exhibited the highest values of TEWL and the forearms the lowest.

Conclusion: In view of the high “sensitivity” of the cheek as compared to the forearm, it will be more cautious to assess the safety of facial cosmetics on the sites of intended use.
Electrical impedance and other physical parameters as related to lipid content of human stratum corneum
Authors: Nicander I. , Norlen L. , Brockstedt U. , Rozell B. Lundh , Forslind B. , Ollmar S.
Published: October 2006

Background/aims: In previous studies we have shown that variations in the properties of the stratum corneum are reflected by alterations in electrical impedance. The aim of this study was to explore the ability of the electrical impedance technique to detect changes in the lipid content of the stratum corneum, and to compare It with the other non‐invasive methods, measurement of transepidermal water loss and of skin moisture.

Methods: Twenty‐two healthy test subjects were recruited. Transepidermal water loss was measured at standard sites on the forearms and wrists, followed by skin moisture estimation by electrical capacitance, and finally by the recording of electrical impedance spectra in the frequency range 1 kHz to 1 MHz. Readings by all three methods were taken before the start of each series of test procedures, as well as after cyclohexane swabbing, a skin stripping procedure and lipid extraction, and also during the recovery process. A mixture of hexane:isopro‐panol was used for lipid extraction of the skin, and the extracts were evaluated using HPLC/LSD and GC/MS/FID analysis. Biopsy samples for light and electron microscopy were obtained after lipid extraction.

Results: Electrical impedance results showed greater changes after lipid extraction than either transepidermal water loss or skin moisture content. Baseline values varied from the cubital fossa to the wrist, both for the non‐invasive methods and for lipid composition.

Conclusions: The electrial impedance is dependent on the lipid content of the stratum corneum, as studied by lipid extraction experiments.
Reproducibility of laser Doppler imager flux measurements within ischemic or venous ulcers and adjacent skin
Authors: Gschwandtner Michael E. , Ambrózy Ewald , Böhler Kornelia , Fasching Sonja , Gaggl Uwe , Schneider Barbara , Ehringer Herbert
Published: October 2006

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 (meanCV±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 meanCV±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, meanCV±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.
Mechanical properties of human skin equivalents submitted to cyclic tensile forces
Authors: Lafrance Hugues , Yahia L'Hocine , Germain Lucie , Auger François A.
Published: October 2006

Background/aims: As human skin equivalents (SE) represent an important breakthrough for clinical grafts and experimental tools, the various methods for mechanical and functional analyses are also gaining importance in the optimization process. SE characteristics have already been studied through indentation‐strength and strain‐energy methods. Since repeated tensile loading is a common reality of skin, we present in this paper the evolution of the indentation readings method for SE, including its dermal equivalent (DE) and collagen gel (CG), during cyclic tests.

Methods: Briefly, the in vitro production of the disk‐shaped (25.4‐mm‐diameter) SE is based on the culture, under submerged conditions, of keratinocytes seeded on our anchorage‐based DE, a human type I+III CG supplemented with elastin and GAGs. All specimens were submitted to quasi‐static ramp‐deflection cycles induced by means of an actuated hemispherical head (12.7‐mm‐diameter). We studied the effects of repeated loading through monitoring of the indentation load (P) versus the deflection (Δ) and the relaxation of P over 1000 s.

Results: With the help of the P‐Δ indentation curves, we determined characteristics for typical CG, DE and SE. Following the respective loading history for each specimen, we demonstrated that the loading and unloading branches, the residual and the upper P, and the hysteresis shaped by the loading‐unloading loop were consistent characteristics in the functional analysis of tissue engineered dermis and epidermis.

Conclusion: The P‐Δ indentation curves obtained from a loading history give valuable characteristics that allow accurate description of the mechanical behavior of tissue engineered skins during their optimization process for transplantation or experimental purposes.
Open application assay in investigation of subclinical irritant dermatitis induced by sodium lauryl sulfate (SLS) in man: advantage of squamometry
Authors: Charbonnier Veranne , Morrison Boyce M. , Paye Marc , Maibach Howard I.
Published: October 2006

Background/aims: After a single occlusive application (24 h patch test), SLS can cause irritation, dryness, and tightness. In typical use, clinical surfactant exposure is usually brief, of open application, and cumulative. The open application model becomes relevant when phenomena, such as dryness and subclinical, i.e., non‐visible, irritation are induced.

Methods: Exaggerated hand wash was performed in a total of 21 healthy individuals. Signs of skin irritation were scored, and skin reactions were measured using various bioengineering techniques.

Results: These studies demonstrate that an exaggerated hand wash model permits exploration of sub‐clinical irritation.

Conclusions: Squamometry proved to be a sensitive, complementary method to detect surfactant‐induced, sub‐clinical skin alterations.
Transepidermal water loss kinetic modeling approach for the parameterization of skin water dynamics
Authors: Rodrigues Luis , Pinto Pedro , Galego Nuno , Da Silva Pedro A. , Pereira Luis Marcelo
Published: October 2006

Background/aims: The evaluation of transepidermal water loss (TEWL) is one of the methods most frequently used in studies involving skin water dynamics. However, TEWL does not provide a direct measurement of epidermal barrier function, being rather a surrogate effect of it. In particular, when external stimuli change cutaneous water balance, these stimuli must be taken into account in order to achieve a rigorous interpretation of the results. Since TEWL is primarily attributed to the water flux from the deepest layers of the skin, through the epidermis, and towards the external environment, this whole process is reasonably compliant with Fick's first law of diffusion. Within this perspective, the aim of this work was to develop a two compartment mathematical model capable of quantitatively describing cutaneous water mass balance over time and thus to provide practical and objective comparable parameters that are particularly useful for studies critically depending on a precise evaluation of TEWL.

Methods: The theoretical basis for the proposed model was tested with data collected from different protocols that use TEWL as the main indicator of induced cutaneous alterations. Those alterations involved either external inputs or intrinsic changes on the cutaneous pathway capable of changing the whole water balance across the skin, either altering epidermal cohesion or promoting a significant influx of external water.

Results: Both the evaporation and the hydration equilibrium processes, merged within the TEWL curve profiles, were thoroughly described in a quantitative fashion using a mathematical model. Direct parameters were calculated, such as kinetic rate constants (khydr and kevap) and half‐life times (t1/2 hydr and t1/2 evap) chosen to describe the hydration and evaporation processes. Secondary parameters, such as time to reach the maximum and an area under the curve derived parameter, the dynamic water mass (DWM), were also calculated, providing additional data particularly useful for comparisons.

Conclusion: Modelling TEWL experimental data in a compartmental analysis framework provides valuable parameterized information for characterising and comparing results. Numerical parameters derived on solid theoretical assumptions are reliable indicators for many situations, as long as those assumptions are not violated. The proposed bicompartmental model may also be suitable for other cutaneous water balance related variables, such as capacitance or conductance, although eventually based on distinct model assumptions. In any case, this modelling conceptualisation seems to render valuable insights into the kinetic description of the main processes involved in the net evaporation and water distribution within the complex human skin hydration process.
Optical coherence tomography in dermatology
Authors: Pagnoni A. , Knuettel A. , Welker P. , Rist M. , Stoudemayer T. , Kolbe L. , Sadiq I. , Kligman A. M.
Published: October 2006

Background/alms: Optical coherence tomography is a new in vivo imaging tool originally developed to investigate the eye. We undertook a preliminary investigation of experimental and clinical dermatological applications.

Methods: We obtained optical coherence tomography images of ethnic groups, of cutaneous changes induced by exposure to water and dimethyl sulfoxide, of corticosteroid atrophy and of acne vulgaris.

Results: Optical coherence tomography was able to visualize specific structural changes in stratum corneum and viable epidermis in these diverse conditions.

Conclusions: The high lateral and axial resolution of 4 urn and 7 μm, respectively, and the image quality of this prototype make optical coherence tomography a promising instrument for clinical and investigative dermatology.
Minimal erythema dose in UV‐shielded and UV‐exposed skin predicted by skin reflectance measured pigmentation
Authors: Lock‐Andersen Jôrgen , de Fine Olivarius Frederik , Haedersdal Merete , Poulsen Thomas , Wulf Hans Christian
Published: October 2006

Aims: To investigate the relationships between epidermal thickness, age, skin pigmentation and UV sensitivity in sun‐exposed skin and skin not exposed to the sun in healthy people without skin cancer or skin diseases.

Methods: Phototesting with a xenon arc solar simulator was performed in 137 healthy Caucasians in buttock skin un‐exposed to UV (27 children, 34 young adults and 32 older adults) and in skin of the back exposed to UV (44 young adults). The pigmentation of the phototest sites was measured objectively by a skin reflectance spectrometer before phototesting. Thickness of the stratum corneum and the cellular epidermis were measured in skin biopsies from the phototest sites. All measurements were performed in the winter and spring months.

Results: Stratum corneum and cellular epidermis were thinner at the back than at the buttocks (P<0.01). Thickness of the stratum corneum at the back or the buttocks was not related to the degree of skin pigmentation (P=0.62 and P=0.20, respectively). Thickness of the stratum corneum at the buttocks was unaffected by gender (P=0.42) and age (P=0.83) whereas cellular epidermis decreased with age (P<0.01) and was thinner in females than in males (P<0.01). In spite of the higher pigmentation at the back than at the buttocks, the minimal erythema dose (MED) was lower at the back than at the buttocks (x=2.7 and x=2.2 SED's, respectively; P=0.04). Given the same degree of skin pigmentation, there was no difference in the MED in buttock skin in children, young adults and older adults un‐exposed to UV (P= 0.61). Prediction of the MED in un‐exposed buttock skin and in exposed skin of the back by a theoretical model based on an exponential function of the measured skin pigmentation was found to provide good estimates of the MED determined by phototest.

Conclusion: Skin pigmentation at un‐exposed buttock skin can reliably predict the constitutive UV sensitivity in healthy Caucasian children and adults and is recommended in surveys where phototesting cannot be performed.
Comparative study of five instruments measuring stratum corneum hydration (Corneometer CM 820 and CM 825, Skicon 200, Nova DPM 9003, DermaLab). Part II. In vivo
Authors: Fluhr Joachim W. , Gloor Max , Lazzerini Sabrina , Kleesz Peter , Grieshaber Romano , Berardesca Enzo
Published: October 2006

Background/aims: The hydration state of stratum corneum can be measured with different instruments. In the present study, five instruments were compared under different experimental in vivo conditions: Corneometer CM 820 and CM 825 (both capacitance based), Skicon 200 (conductance), Nova DPM (impedance based capacitance) and DermaLab (capacitance).

Methods: Seven anatomical sites were tested, a sorption‐de‐sorption test (SDT) and a moisture accumulation test (MAT) were performed. Different hydration states were created on the volar forearms by occluded application of an oil‐in‐water (o/w) emulsion, glycerol and urea containing oil‐in‐water (o/w) emulsion, an untreated control site and a site after lipid extraction with acetone. Measurements were performed 15 min after removal of occlusion.

Results: The coefficient of variation for CM 820 ranged between 9.3% and 23.7%; for CM 825 between 14.9% and 36.8%; for Skicon 200 between 53.0% and 167.3%; for Nova DPM between 36.4% and 95.8%; for DermaLab between 23.6% and 45.6%. All devices showed a highly significant correlation (P<0.0001) with a high Spearman coefficient r ranging between 0.7928 and 0.9358.

Conclusions: CM 820 and CM 825 seem to differentiate more precisely than Nova DPM, Skicon 200 and DermaLab in dry conditions according to previous findings, i.e., that conductance measurements might be more sensitive for hydrated skin and capacitance measurements might be more sensitive for dry skin conditions. The CM 825, the Skicon 200 and the Nova DPM are suitable for dynamic measurements of hydration parameters of the stratum corneum.
Comparison of cheek and forehead regions by bioengineering methods in women with different self‐reported “cosmetic skin types”
Authors: Fur Isabelle Le , Lopez Sabine , Morizot Frédérique , Guinot Christiane , Tschachler Erwin
Published: October 2006

Background/aims: Understanding structural and functional differences between facial areas is necessary for the formulation of cosmetics and dermatological preparations well tailored to the skin's biophysical characteristics. The objective of the present study was to compare biophysical parameters on malar and frontal facial areas of healthy women classified according to self‐reported cosmetic skin types.

Methods: The study population comprised 253 women aged from 20 to 50 years who did not display any signs of dermatological disease. Women declared spontaneously their cosmetic skin type. Skin capacitance, sebum casual level, skin temperature, transepidermal water loss (TEWL), skin colour and relief were assessed on cheeks and forehead in a controlled environment.

Results: All biophysical parameters showed statistically significant differences between the two zones. Mean a* chromametric values and TEWL values were significantly higher on cheeks. In contrast, mean b* chromametric values and sebum casual levels showed the highest values on the forehead. Moreover, skin capacitance, temperature, roughness and L.* chromametric value showed minor, while statistically significant, differences between the two zones. With marginal exceptions, the differences between the facial zones for each biophysical parameter remained statistically significant, irrespective of self‐reported skin type.

Conclusion: Biophysical parameter mean values differ between frontal and malar zones regardless of self‐reported skin type. Except for the elevated sebum casual levels in “greasy” and “combined” skin, no single or combined biophysical characteristics could be linked to any of the self‐reported skin types. Furthermore our data confirm that in contrast to the common belief that “dry” skin is associated with reduced sebum production, sebum levels in women declaring to have “dry” skin and those declaring to have “normal” skin were not found to be different.
Two possible classifications of facial skin type by two parameters in Korean women: sebum excretion rate (SER) and skin surface relief (SSR)
Authors: Park Sun Gyoo , Kim Young Deuk , Kim Jin Jun , Kang Seh Hoon
Published: October 2006

Background/alms: Worldwide there are many skin care and makeup products intended to maintain good appearance or youthful skin. However consumers don't know which products are suitable for their skin because they don't know their skin type exactly. To solve this problem, this study suggests two possible classifications of facial skin type by using simple methods.

Methods: In 662 healthy volunteers, sebum excretion rate (SER) on the forehead and cheek, and skin surface patterns on the cheek were examined by using Sebutape® and skin replica, respectively.

Results: The measured SER values from the forehead were 0.06‐4.56 ng/cm2/min and those from the cheek were 0.04‐3.80 ng/cm2/min. From these data, five facial skin types were classified by SER: low SER type, medium SER type, high SER type, combination‐1 SER type, and combination‐2 SER type. Twelve facial skin types were also classified; they were determined by star formation (SF), primary lines (PL), secondary lines (SL) and pore size from magnified skin surface relief (SSR) of the cheek.

Conclusions: From this study, we suggest new classifications of skin types by SER and SSR. The SER and the parameters of skin surface texture (SF, PL, and SL) decreased with age and the pore size increased with age. Although these methods did not classify facial skin types perfectly, we were able to check consumer's facial skin types simply and more quickly.
Rapid in vivo measurement of the topography of human skin by active image triangulation using a digital micromirror device
Authors: Jaspers S. , Hopermann H. , Sauermann G. , Hoppe U. , Lunderstädt R. , Ennen J.
Published: October 2006

Background/aims: Topometry is one of the most relevant methods for biophysical research on skin in dermatologic and cosmetic science, because it relates very closely to the perceived quality of skin. Taking silicon replicas of skin sites under investigation and measuring those imprints with mechanical or optical profilometers is still the most frequently used method. Direct measurement of the topography of human skin in vivo by active image triangulation avoids the need to make replicas and seems to be a promising alternative.

Methods: The introduction of active image triangulation in conjunction with phase‐shift techniques in skin topometry enables a fast and non‐invasive measurement of the skin surface in vivo. The main attribute of the proposed system is the projection of a regular sinusoidal intensity pattern with a sophisticated digital projection device onto the surface of skin under a certain angle of incidence. The height information of the structured surface is coded in the distorted intensity pattern, which is recorded by an appropriate video technique.

Results: Successful in vivo measurements of selected body sites and measurements on scar, nevus, wound and wrinkles are presented in this paper. Furthermore, irritation of skin, influence of hydration of skin, and differences between youthful and elderly skin can be detected in the measurement results of the new optical system.

Conclusions: For measuring the topog raphy of human skin, active image triangulation is appropriate both for macrotopometry (nevus, scar, wound) and for microtopometry (casts, selected body sites). This new non‐contact technique allows dynamic measurements of alterations in skin topography as a consequence of certain treatments (e.g., application of ingredient, hydration of skin) without removal of corneocytes or scales. Optical three‐dimensional (3D) topometry using active image triangulation appears to offer a significant improvement in speed and flexibility, providing a fast and accurate analysis of skin surface topography.
Seasonal variation in adhesive tape stripping of the skin
Authors: Tokumura F. , Ohyama K. , Fujisawa H. , Nukatsuka H.
Published: October 2006

Background/aims: The seasonal variation in various properties of adhesive tapes on the skin was evaluated.

Methods: In February, April, and August, five general‐purpose adhesive tapes were applied on the forearms of 12 healthy male volunteers for 24 h. The dermal peeling force, the accumulation of fluid, the amount of stripped corneocytes, and the dermal reaction at 1 h after removal of the tapes were evaluated.

Results/Conclusions: The various properties of adhesive tapes on the skin were closely related to the accumulation of fluid beneath the applied tape. Because the accumulation of fluid was significantly higher in summer than in winter, the dermal peeling force was lower in summer than winter. However, the number of stripped corneocytes and the dermal reaction of the inner area under the applied tapes were larger in summer than in winter. Though tha dermal peeling force, the accumulation of fluid, and the number of stripped corneocytes are generally considered as dermal irritation factors, the accumulation of fluid and the number of stripped corneocytes may exert a great influence on the seasonal variation in dermal irritation. On the other hand, the dermal reaction of the edge section had no tendency to vary with season. Because the edge reaction should be caused by interference with skin movement by the stiff backing or the adhesive, it seems to be uninfluenced by the accumulation of fluid.
Early adaptation of human skin following birth: a biophysical assessment
Authors: Visscher Marty O. , Maganti Srinath , Munson Karen A. , Bare Diane E. , Hoath Steven B.
Published: October 2006

Background/aims: Successful adaptation to postnatal life requires rapid physiological transitions in multiple organ systems. Mechanisms regulating stratum corneum water interactions and evaporative heat loss, for example, are pivotal in making the transition from the warm, aqueous prenatal state to a cold, dry postnatal environment. Understanding these mechanisms is important in formulating skin care guidelines in early infancy.

Methods: One hundred and one full term infants were enrolled prospectively and evaluated in three maternity hospitals over the first few hours after birth. Skin surface electrical capacitance and optical imaging were performed over selected body sites after placement under a radiant warming device. A selected group of infants were occluded with a plastic wrap following towel drying in the delivery room. Specific measurements included baseline skin hydration, continuous capacitive reactance, peak water sorption, rate of water desorption, skin pH, and grading of optical images for abnormal skin desquamation.

Results: Occlusion of the skin surface following birth delays the normal fall in surface hydration and transepidermal water movement (TEWM). Sites exposed to the radiant warmer (chest) exhibited decreased hydration and increased pH compared to non‐exposed sites (back). Desquamation was increased over the chest compared to the back as judged by optical image grades. Significant inverse correlations were noted between baseline skin hydration and the ability to desorb surface water. Unexpectedly, females exhibited significantly increased desorption of exogenously applied water with a near significant increase in maternal‐infant bonding time.

Conclusions: Newborn infant stratum corneum undergoes a slow (minutes to hours) diminution in surface hydration following birth; this is a function of body site, position, and exposure to the radiant warmer. Practices such as occlusion of the skin surface at birth delay the normal drying process. The data support potential gender specific differences in skin surface water handling and/or delivery room practices. Focus on the complex process of newborn skin adaptation provides a physiological framework for skin care protocols extending into infancy, childhood, and later life.
Cutaneous pH in children affected by atopic dermatitis and in healthy children: a multicenter study
Authors: Sparavigna A. , Setaro M. , Gualandri V.
Published: October 2006

Background/aims: Several studies have been conducted in order to assess, objectively and non‐invasively, atopic skin parameters. Since little is known about clinically uninvolved, perilesional and lesional skin pH in atopic children at different stages of the disease, we studied cutaneous pH in atopic and healthy children and investigated possible relationships among different sites, phases of the disease and main symptoms.

Methods: Two hundred and eighty‐four children of both sexes, 143 atopic and 141 healthy children, aged 3 months to 11 years, examined in 10 different Italian dermatological centres were included in the study and subjected to clinical examinations and pH measurements.

Results: Atopic children presented statistically significant higher pH values than controls, not only at the level of eczematous lesions (P=0.004) and of perilesional skin (P=0.003) but also at the level of apparently healthy skin (P=0.002). A progressive statistically significant increase in pH values was observed from healthy to perilesional to lesional skin. In acute dermatitis, children affected by moderate itching (considering itching complaints and scratching lesions) presented, at the level of lesional and perilesional skin, statistically significant higher pH values than children affected by mild itching.

Conclusion: The correlation found in this study between severity of itch and skin surface alkalinity, far from demonstrating a therapeutic role of acidic substances against itching in atopic children, deserves new epidemiological studies on a large scale in order to identify new strategies of treatment of atopic skin.
Ultrasound evaluation of acute experimental and chronic clinical wounds
Authors: Rippon M. G. , Springett K. , Walmsley R.
Published: October 2006

Background/aims:An ultrasonic pulse echo Imaging technique was used to visualise various characteristics of experimentally induced acute full‐thickness wounds. These characteristics were monitored over time as wound healing progressed. Data obtained from this work have been extrapolated to allow monitoring of healing and non‐healing wounds in a human clinical environment.

Methods:Acute experimental full‐thickness wounds were monitored using pulsed ultrasound (20 MHz) over a period of 21 days. The scans were interpreted in the light of data obtained from previous studies, clinical observations and current knowledge of wound healing. Similarly, ultrasound scans of healing and nonhealing clinical wounds were evaluated over a 6‐week period. Ultrasound scans of amputated tissue were compared with the same site of histology to support scan evaluations of anatomical changes in ulcerated and adjacent tissue.

Results:The serial ultrasound scans of acute experimental full‐thickness wounds demonstrated that changes in wounds could be observed and that specific events occurring during wound healing could be monitored, e.g., granulation tissue formation, reepithelialisation and wound contraction/fill. Specifically, these events were related to clinical observations of accumulation/synthesis of fibrotic (collageneous) tissue within the wound. Reepithelialisation of the wound could be monitored but was more problematic in quantitative evaluations.

Conclusions:Ultrasound can be used to monitor non‐invasively and sequentially events that occur during acute wound healing. This information may be useful in extrapolating to healing and non‐healing clinical wounds and may provide a diagnostic tool to identify early signs of tissue breakdown prior to ulceration.
Palpation of the skin with a robot finger: an attempt to measure skin stiffness with a probe loaded with a newly developed tactile vibration sensor and displacement sensor
Authors: Sasai Shu , Zhen Ya‐Xian , Suetake Takaki , Tanita Yasuo , Omata Sadao , Tagami Hachiro
Published: October 2006

Background/aims: Various attempts have been made to measure mechanical properties of the skin quantitatively and noninvasively. However, no attempt has been made to measure a tactile sense of our finger that palpates the skin; when we palpate the skin to search for any change, we at first rub the skin surface softly with a finger tip to detect a surface change and then press the finger against the skin to perceive any alteration in consistency. The problem here is how to record such tactile sense quantitatively, because the palpating examination for smoothness or softness of the skin totally depends on a subjective perception. A new tactile sensor from robot technology is equipped with a fingertip‐like sensing probe oscillating at a resonant frequency of 60 kHz; it is capable of clearly sensing small differences in hardness of solid substances from a change in the oscillating frequency and from a displacement sensor that detects depressability of the skin. We have used this new measuring system to evaluate the hardness and elasticity of skin.

Methods: We constructed a probe with two independent sensors, i.e., a newly developed tactile vibration sensor and a displacement sensor. To determine its usefulness we first used an in vitro skin model and subsequently used normal and lesional skin, such as neutrophilic erythema, keloid, hypertrophic scar, and scleroderma.

Results: Two parameters were obtained with our probe: one that reflected superficial firmness of the skin, which mainly correlated with the hydration state of the stratum comeum, and the other that reflected the firmness of deeper tissue.

Conclusion: Our results showed that this probe is useful for evaluating the physical properties of skin lesions that accompany changes in skin firmness.
Single exposure phototesting utilizing a divergent ultraviolet beam
Authors: Ilias Michail A. , Anderson Chris , Wårdell Karin
Published: October 2006

Background/aims: Confident diagnosis of photosensitivity in patients with light dermatoses requires skin exposure to well determined ultraviolet (UV) light doses, most often from a solar simulator. The traditional test procedure results in a rough classification of skin sensitivity based on the minimal erythema dose (MED) found for each patient. The limited number of constant irradiance doses used during phototesting decreases the precision of the MED value. In the present study we aimed at developing the technical system for the determination of MED by using a single, centrifugally attenuating, UVB provocation.

Methods: A divergent UV beam was achieved with the help of an optic lens. To investigate the irradiance profile, an irradiance acquisition system was built that produced three‐dimensional intensity maps. In addition, a laser Doppler perfusion imaging (LDPI) system was introduced in the evaluation of the skin response along with visual readings of the same exposed areas, in order to add a quantitative aspect to the assessment of erythema. The procedure was used on one test subject.

Results: The divergent UV beam showed the desired profile. With the current setup 20 different UV‐dose levels could be discriminated. Relevant UV‐dose levels were determined and tested on a subject, which in practice gave results in the form of visual assessment as well as LDPI‐images. The visual or LDPI diameter gave the MED. Within the skin reaction, irradiance and the laser Doppler values could be compared mm for mm.

Conclusions: A more accurate MED determination with a single UV exposure seems to be feasible by using the proposed method. Though further investigation is required, the technique appears to offer new possibilities for the association of dose to response. In addition LDPI is possibly a useful complement to the visual readings of the skin responses, since the method gives a quantification of the grade of erythema, as opposed to visual (+, ++, +++) readings that are subjective and at best semiquantitative.
Effect of antioxidants and free radical scavengers on protection of human skin against UVB, UVA and IR irradiation
Authors: Muizzuddin Neelam , Shakoori Abdul Rauf , Marenus Kenneth D.
Published: October 2006

Background/aims: This study was designed to observe the effect of a mix of commercial antioxidants and free radical scavengers (AO) on protection of human skin against different wavelengths of the solar spectrum: 280‐320 nm (UVB), 320‐400 nm (UVA) and 400‐900 nm (IR).

Methods: Healthy volunteers were chosen from the local population and exposed to the three aspects of the solar spectrum. Erythema at 24 h, immediate pigment darkening (IPD) and immediate erythema were employed as markers for UVB, UVA and IR exposure, respectively.

Results: Based on 24 h erythema measurements, the AO mix afforded about 2.6‐fold (163%) protection against UVB‐induced erythema (Table 1). IPD measurements after UVA exposure exhibited 76% protection afforded by the AO mix. The AO mix reduced IR‐induced increases in erythema and blood flow by 43% and 52%, respectively (Table 1).

Conclusions: Data from these studies suggest that treatment with antioxidants prior to exposure to solar irradiation allows protection of human skin against IR as well as UVB and UVA. Antioxidants and free radical scavengers may be valuable adjuncts to traditional sunscreens, for protection of skin against the effects of actinic exposure that, over a long term, can result in formidable consequences such as skin cancer and photo‐aging.
Diverse CD81 Proteins Support Hepatitis C Virus Infection
Authors: Flint Mike , von Hahn Thomas , Zhang Jie , Farquhar Michelle , Jones Christopher T. , Balfe Peter , Rice Charles M. , McKeating Jane A.
Published: October 2006

Hepatitis C virus (HCV) entry is dependent on CD81. To investigate whether the CD81 sequence is a determinant of HCV host range, we expressed a panel of diverse CD81 proteins and tested their ability to interact with HCV. CD81 large extracellular loop (LEL) sequences were expressed as recombinant proteins; the human and, to a low level, the African green monkey sequences bound soluble HCV E2 (sE2) and inhibited infection by retrovirus pseudotype particles bearing HCV glycoproteins (HCVpp). In contrast, mouse or rat CD81 proteins failed to bind sE2 or to inhibit HCVpp infection. However, CD81 proteins from all species, when expressed in HepG2 cells, conferred susceptibility to infection by HCVpp and cell culture-grown HCV to various levels, with the rat sequence being the least efficient. Recombinant human CD81 LEL inhibited HCVpp infectivity only if present during the virus-cell incubation, consistent with a role for CD81 after virus attachment. Amino acid changes that abrogate sE2 binding (I182F, N184Y, and F186S, alone or in combination) were introduced into human CD81. All three amino acid changes in human CD81 resulted in a molecule that still supported HCVpp infection, albeit with reduced efficiency. In summary, there is a remarkable plasticity in the range of CD81 sequences that can support HCV entry, suggesting that CD81 polymorphism may contribute to, but alone does not define, the HCV susceptibility of a species. In addition, the capacity to support viral entry is only partially reflected by assays measuring sE2 interaction with recombinant or full-length CD81 proteins.
Rotavirus Infection Is Not Associated with Small Intestinal Fluid Secretion in the Adult Mouse
Authors: Kordasti Shirin , Istrate Claudia , Banasaz Mahanez , Rottenberg Martin , Sjövall Henrik , Lundgren Ove , Svensson Lennart
Published: October 2006

In contrast to humans, adult but not infant small animals are resistant to rotavirus diarrhea. The pathophysiological mechanism behind this age-restricted diarrhea is currently unresolved, and this question was investigated by studying the secretory state of the small intestines of adult mice infected with rotavirus. Immunohistochemistry and histological examinations revealed that rotavirus (strain EDIM) infects all parts of the small intestines of adult mice, with significant numbers of infected cells in the ilea at 2 and 4 days postinfection. Furthermore, quantitative PCR revealed that 100-fold more viral RNA was produced in the ilea than in the jejuna or duodena of adult mice. In vitro perfusion experiments of the small intestine did not reveal any significant changes in net fluid secretion among mice infected for 3 days or 4 days or in those that were noninfected (37 ± 9 μl · h−1· cm−1, 22 ± 13 μl · h−1· cm−1, and 33 ± 6 μl · h−1· cm−1, respectively) or in transmucosal potential difference (4.0 ± 0.3 mV versus 3.9 ± 0.4 mV), a marker for active chloride secretion, between control and rotavirus-infected mice. In vivo experiments also did not show any differences in potential difference between uninfected and infected small intestines. Furthermore, no significant differences in weight between infected and uninfected small intestines were found, nor were any differences in fecal output observed between infected and control mice. Altogether, these data suggest that rotavirus infection is not sufficient to stimulate chloride and water secretion from the small intestines of adult mice.
Selection of Early-Occurring Mutations Dictates Hormone-Independent Progressionin Mouse Mammary TumorLines
Authors: Gattelli Albana , Zimberlin María N. , Meiss Roberto P. , Castilla Lucio H. , Kordon Edith C.
Published: October 2006

Mice
harboring three mouse mammary tumor virus (MMTV) variants develop
pregnancy-dependent (PD) tumors that progress to pregnancy-independent
(PI) behavior through successive passages. Herein, we identified 10
predominant insertions in PI transplants from 8 independent tumor
lines. These mutations were also detected in small cell populations in
the early PD passages. In addition, we identified a new viral insertion
upstream of the gene
Rspo3
, which is overexpressed in three of
the eight independent tumor lines and codes for a protein very similar
to the recently described protein encoded by
Int7
.
This study suggests that during progression towards hormone
independence, clonal expansion of cells with specific mutations might
be more relevant than the occurrence of new MMTV
insertions.
Interaction of Adenovirus Type 5 Fiber with the Coxsackievirus and Adenovirus Receptor Activates Inflammatory Response in Human Respiratory Cells
Authors: Tamanini Anna , Nicolis Elena , Bonizzato Alberto , Bezzerri Valentino , Melotti Paola , Assael Baroukh M. , Cabrini Giulio
Published: October 2006

The innate immune response to adenovirus (Ad)-derived gene transfer vectors has been shown to initiate immediately after interaction of Ad with respiratory epithelial cells, through the induction of extracellular signal-regulated kinase 1 and 2 (ERK1/2) and JNK mitogen-activated protein kinase (MAPK), nuclear factor κB (NF-κB), and different proinflammatory genes. Ad serotypes 2 or 5 (Ad2/5) enter respiratory epithelia after initial binding of fiber with the coxsackievirus-adenovirus receptor (CAR) or, alternatively, with cell surface heparan sulfate glycosaminoglycans. Ad2/5 internalization is triggered by binding of penton base to cellular RGD-binding integrins. Here we investigated the role of the Ad5 surface domain proteins constituting the vector capsid, namely, the fiber, the penton base, and the hexon, on the transmembrane signals leading to the transcription of the different proinflammatory genes in the human respiratory A549 cell line. Interaction of Ad fiber with CAR activates both ERK1/2 and JNK MAPK and the nuclear translocation of NF-κB, whereas no activation was observed after exposing A549 cells to penton base and hexon proteins. Moreover, interaction of Ad fiber with CAR, but not heparan sulfate proteoglycans, promotes transcription of the chemokines interleukin-8, GRO-α, GRO-γ, RANTES, and interferon-inducible protein 10. These results identify the binding of Ad5 fiber with the cellular CAR as a key proinflammatory activation event in epithelial respiratory cells that is independent of the transcription of Ad5 genes.