bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sources of unwanted variability in measurement and description of skin surface topography
Authors: Connemann Bernhard J. , Busche Heidrun , Kreusch Jürgen , Wolff Helmut H. 
Published: October 2006

Background/aims: Quantitative measurement of skin roughness has proved to be a valuable tool in the efficacy‐control of external applications, but it suffers from not yielding easily comparable results. The most important sources of inter‐observer variability are high‐pass filters used to separate roughness and waviness, and low‐pass filters which result from the finite resolution of the instrument or from the finite sampling interval of digital measurement. In the present study, the effects of high‐pass filters and sampling intervals on the roughness measured were investigated.Methods: Dynamically focusing optical profilometry was used to measure the surfaces of negative replicas of healthy human skin. High‐pass cut‐off wavelengths and sampling intervals were varied systematically.Results/conclusions: Virtually unbiased estimates for the roughness parameters K, Sk, Rq, and Ra can be obtained using sampling intervals of 40 or even 80 μm. Regarding these roughness parameters, it is far better to do more scans than to shorten the sampling interval. The roughness parameters Rz, Rp, Rt, Rpm, Rmax, Pt, on the other hand are very sensitive to the influence of the sampling interval; to achieve satisfying estimates, the sampling interval should be no longer than 2 to 5 urn; as an important parameter’of the measurement, it is worthy of remark and should always be indicated. The way the mean square roughness Rq depends on the cut‐off wavelength is not well described by the Sayles‐Thomas‐relation Rq∼λc0.5. If the power‐spectrum |h*(v)|2 approximates sufficiently to a power law, |h*(v)|2∼vδ, a better estimate is given by Rq∼λcγ with γ=‐(δ+1)/2. In many cases, γ=1 or Rq∼λc will suffice.
Evaporimetiy in the differentiation of allergic, irritant and doubtful patch test reactions
Authors: Giorgini Simonetta , Brusi Claudio , Sertoli Achille 
Published: October 2006

Background/aims: The aim is to evaluate, using evaporimetry, the possibility of getting further information supporting clinical reading of allergic, irritant reactions and doubtful patch test reactions.Methods: The investigation was carried out on 204 patients (182 female and 22 male, mean age 31.6 years), patch tested routinely as suspects of allergic contact dermatitis. We evaluated 326 reactions (203 allergic, 123 irritant or doubtful).Results: Mean values pf TEWL were: for the positive allergic reactions, 7.21 (SD, 2.26) at 48 h, 15.77 (SD, 5.50) at 72 h; and for the irritant or doubtful reactions, 7.55 (SD, 1.72) at 48 h, and 5.77 (SD, 1.41) at 72 h. TEWL in the 2 reactions groups at 72 h was significantly different (p<0.01).Conclusions: The study shows (i) concordance between the evaporimeter values and the visual score; (ii) at 72 h, the evaporimeter values are increased in the allergic reactions but not in irritant or doubtful reactions; (iii) evaporimetry in the differential diagnoses of patch test reactions was deemed useful.
Comparison of human back versus arm skin region for its suitability to test weak irritants
Authors: Lavrijsen A. P. M. , Geelen F. A. M. J. , Oestmann E. , Hermans J. , Bodda H. E , Ponec M. 
Published: October 2006

Background/aims: Large‐scale comparative screening of der‐matological and cosmetic products require non‐invasive bioengineering methods which give reproducible results that can be statistically analyzed. To determine the most suitable test region for testing irritating substances, the response of the skin to the weak irritant sodium lauryl sulphate (SLS) was measured on standardized locations on the forearm and back. Furthermore, using 3 bioengineering methods, we aimed to establish the most sensitive method to measure skin response to SLS.Methods: The baseline measurements of transepidermal water loss (TEWL), cutaneous blood flow (CBF) and skin colour a*‐value were performed at 6 standardized locations on the volar forearms and at 12 locations on the back on 2 consecutive days, day 1 and 2, in 9 healthy volunteers. On day 2, 9 out of the 18 sites were exposed to 0.5% SLS by occlusive 24‐h patches and the skin response was evaluated on days 3 and 4.Results: For TEWL, CBF and a*‐value, no significant regional variations were found within individuals at any time on the arm locations and on the back locations. However, significant inter‐individual variation was found. At the back on day 4, a slightly higher skin response to SLS was found compared to that found on the forearms as measured by TEWL and the a*‐value. Of the 3 bioengineering methods used, TEWL was the most sensitive method to detect cutaneous response to the weak irritant used. TEWL measurements on days 1 and 2 performed at the 6 standardized locations on the volar forearms inside and outside a specially constructed air convection protection box, showed no relevant differences in measured TEWL values.Conclusion: Both the forearms and the back were found to be suitable sites for irritancy testing. Since considerable differences in mean reactivity between subjects have been observed the use of large numbers of subjects in predictive irritant patch testing is required.
Barrier function of the skin in a repetitive irritation model and influence of 2 different treatments*
Authors: Gabard B. , Eisner P. , Treffel P. 
Published: October 2006

Background/aims: The aim of this study was to develop and characterize an experimental model of cumulative irritant contact dermatitis using the repetitive application over 2 weeks of 2 different irritative stimuli, sodium lauryl sulphate (SLS) in low concentration and toluene. Further, it was intended to look at the effect of 2 different treatments which could influence the regeneration of the skin barrier, as already investigated in preliminary short‐term experiments.Methods: Occlusive short‐time daily application of the irritants (SLS 30 min; toluene 10 min) was performed. After removal of the occlusive patch, the irritated areas were treated with 2 different preparations, Lotio Alba Aquosa and vaseline (white petroleum jelly). Bioengineering techniques were used to precisely measure the skin condition.Results: A mild irritation was obtained under these experimental conditions. The bioengineering measurements allowed us to differentiate both irritants through their different influences on trans‐epidermal water loss and skin hydration. Treatment with vaseline did not significantly influence the course of the irritation, but Lotio Alba Aquosa clearly potentiated it, whereby different effects were noticed for both irritative stimuli.Conclusions: The use of bioengineering techniques in this model of mild cumulative irritation allowed us to differentiate the action of both irritants, showing that they act through different mechanisms. The results of the treatments pointed out the need to treat an irritation with the right product for the right time period.
Bioengineering measurements of barrier creams efficacy against toluene and NaOH in an in vivo single irritation test
Authors: Treffel P. , Gabard B. 
Published: October 2006

Background/aims: By now, only a few models have been published with the goal of testing barrier creams in vivo in humans. The aim of this study was to evaluate with a single irritation test, barriers creams in humans against a lipophilic and a hydrophilic irritant, toluene and NaOH, respectively.Methods: Both irritants were applied for 15 min after pretreatment of the skin with barrier creams. Non‐invasive bioengineering methods, such as skin colorimetry (a*) and cutaneous blood flow (CBF) measurements were used to assess product protection.Results: After toluene application on control sites, the irritation appeared quickly (Tmax=3 min after patch removal), was significant (+5‐6 units for a* and+80% for CBF) and did not return to base value within 1 h. Skin irritation after NaOH application, as measured by a*, was less important (+2 units) and occurred later (T“max=40 min after patch removal). For this irritant, CBF response was minor and variable. When testing barrier properties of the products, none of them were able to prevent the skin erythema induced by toluene. Against NaOH, one barrier cream as well as petrolatum and a fatty cream protected the skin significantly.Conclusion: The present study points out the unsatisfactory effectiveness of several commercially available barrier creams claimed to protect against lipophilic or hydrophilic irritants.
Skin critical surface tension
Authors: Khyat A. El , Mavon A. , Leduc M. , Agache P. , Humbert P. 
Published: October 2006

Background/aims: Surface energy phenomena result from molecular interaction between substances. On the skin, they are involved in sweat and sebum dispersion, and in foreign substances, in spreading and absorption. However, they are unknown due to the scarce number of studies. The aim of this work was to find the skin critical surface tension (CST), an index of wettability, through a reliable technique, and to study the influence of skin lipid and of some oil‐in‐water (O/W) and water‐in‐oil (W/O) preparations.Method: The CST was calculated using the Zisman equation, from the contact angle at equilibrium, of droplets of liquids whose surface tension was known. Contact angles were computed from the base and the height of the droplets viewed from their side through an operating microscope provided with a slanted mirror. Both volar forearm and forehead were studied.Results: On volar forearm, the skin CST was 27.5±2.4 dyne/cm (n=12) and normally distributed. Forehead CST was above 50.7 dyne/cm. On both areas, defatting with ether reduced CST down to 21.6±2.6 dyne/cm, and 29.3±1.7 dyne/cm, respectively (p<0.001). Washing with soap reduced forearm CST down to 23.7±1.0 dyne/cm (p<0.01), and occlusion down to 21.6±3.4 dyne/cm (p<0.001). O/W cream application strongly decreased both forearm and glass slide CST, whereas W/O cream application either raised CST or left it unchanged; in all cases, changes were less marked on skin than on glass.Conclusion: These data demonstrate that the skin surface is primarily hydrophobic and paradoxically becomes more wettable through its lipidic component, especially the sebum. Emulsions seemed to interact with the skin and change its CST as would do their continuous phase only.
Electronic UV dosimeters
Authors: Wulf Hans Christian , Gniadecka Monika 
Published: October 2006

Background/aims: The pathogenic role of ultraviolet (UV) in the development of skin cancer, skin ageing and immunosuppression makes it important to monitor human exposure to UV radiation. In a previous study we constructed UVB and UVC dosimeters based on a thermoluminescent phenomenon induced by UV in CaF2:Dy and CaF2 crystals. However, these dosimeters were insensitive to UVA radiation and readout was time‐consuming. In the present study we aimed to develop an electronic dosimeter suitable for UVA, UVB and UVC. The principle of this dosimeter is a measure of accumulated electric current induced by UV on a photodetector.Methods: Electric current induced by UV on a photodetector was accumulated in a Plessey's E‐cell coulometer. A special reading device was constructed to quantify total charge of the coulometer. Sensitivity for UVA, UVB and UVC was achieved by the use of appropriate filters in front of the photodetector.Results: The sensitivity of the electronic dosimeter increased with increasing wavelength of UV radiation; therefore, in UVB and UVC dosimeters the use of amplifiers was necessary. A linear response to UVA, UVB and UVC was achieved.Conclusion: Dosimeters with a linear response to increasing doses of UVA, UVB and UVC have been constructed for personal monitoring of UV exposure.
Remittance spectroscopy of human skin in vivo
Authors: Geyer Annette , Vilser W. , Karte Kerstine , Wollina U. 
Published: October 2006

Background/aims: The skin is an easily accessible organ on which non‐invasive examination methods can be applied. Recently spectroscopic methods have been introduced in characterization of skin under physiological and pathological conditions. To examine remittance spectroscopic qualities of human skin in vivo and to clarify the influence of selected test conditions, a single‐beam spectrometer MCS 410 (Carl Zeiss, Jena, Germany) has been used.Methods: Remittance spectra readings were performed in 35 volunteers. Wavelength ranged from 362 nm to 780 nm. Individual remittance values and their standard deviations were obtained from 20 readings under standardized test conditions. The effect of pressure, rubbing, cooling, washing, greasing and degreasing on average remittance values was investigated. Statistical analysis was done with paired Student's f‐test and Fisher's test.Results: Pressure increased remittance values over a wide range of wavelength, peaking at 518 nm. Greasing and degreasing modified spectral remittance of shorter wavelength peaking around 362 nm. Rubbing and cooling did not induce significant variations of spectral remittance of skin.Conclusion: Spectral remittance provides an individual profile in human skin, which may be influenced by pressure and greasing/ degreasing. To establish standardized test conditions with a narrow range of intra‐individual variation these items have to be kept constant.
Interlaboratory comparison and validity study of the Minolta ChromaMeters CR‐200 and CR‐300
Authors: Fullerton A. , Lahti A. , Wilhelm K.‐P. , Perrenoud D. , Serup J. 
Published: October 2006

Background/aims: Interlaboratory comparison and validity study of the Minolta ChromaMeters. The aim was to study repeatability, day‐to‐day variation, week‐to‐week variation, effects of electrical switch on/off, different pressures used and external light conditions.Methods: A circulation experiment among 4 European laboratories using the same procedures and measurements on the same circulated colour standards (white, pink, red) and on forearm skin. Measurements using both the laboratories actual in‐house calibration setting and calibration of all apparatus against a common white standard tile were performed.Results and conclusions: High instrument repeatability for all apparatus with low coefficients of variation was found. The repeatability was poorer in vivo on forearm skin than on colour plates. Interday reproducibility was found to be high. One apparatus showed an unexpected major shift in a* and b* levels, probably related to the device. Interlaboratory calibration against a common white tile was found inadequate, since a large inter‐individual variation will always be present and will exceed the instrument variability, and since a difference in measuring level among devices could not be overcome. Increased pressure of the probe during forearm skin measurement introduced increased a* values. When doing more than 3 replicative measurements within a test site, the equipment should always be removed between each measurement, since continuous contact may result in larger in vivo variability. No effect was found of turning the electrical power on/off. Neither was ambient light found to influence the measurements. The use of a glass projection tube instead of the normal open tube was found to influence a* by decreasing the value.
Nickel: the search for alternative, optimal and non‐irritant patch test preparations
Authors: E.Wahlberg Jan 
Published: October 2006

Background/aims: Several contact allergens including nickel are also irritants. Ideal patch test preparations should not miss cases of contact allergy and should be non‐irritant. The currently used nickel preparation (5% nickel sulfate in petrolatum; 0.19 m) is a compromise. The present aim was to compare the skin‐irritant potential of various nickel preparations (sulfate, chloride, nitrate in petrolatum and in water) by using the objective, noninvasive laser Doppler technique for assessment.Methods: Preparations with various nickel concentrations and vehicle controls were applied under occlusion (Finn chambers) on the volar forearms of healthy subjects for 48 h. The test sites were examined visually and measured with a laser Doppler flowmeter before, and repeatedly after, removal of test patches. Some preparations were also used when patch testing consecutive dermatitis patients.Results: 0.19 m nickel chloride and nickel nitrate in petrolatum caused erythema as well as increase in skin blood flow, while lower concentrations (0.10, 0.05 and 0.01 m) did not affect skin blood flow. At higher concentrations the sulfate was less reactive than the other salts. The reactivity was more pronounced with the salts in petrolatum than in water. 0.05 m nickel nitrate was equivalent to 0.19 m nickel sulfate in diagnosing contact allergy in patch testing, while 0.30 m nickel sulfate in water missed several cases.Conclusions: The laser Doppler technique is more sensitive than the naked eye and can indicate nickel patch test preparations with marginal irritant properties. Some promising alternative candidates have been identified.
Measurement of croton oil induced rabbit ear swelling and evaluation of anti‐inflammatory agents with a standard low pressure caliper
Authors: Manny‐Aframian V. , Shafran A. , Zlotogorski A. , Ginsburg I. , Dikstein S. 
Published: October 2006

Background/aims: Carbobenzoxy‐phenylalanyl‐methionine (CBZ‐Phe‐Met), a known inhibitor of the chemotactic peptide N‐formyl‐methionyl‐leucyl‐phenylalanine (fMLP) in vitro, has not been evaluated as a topical anti‐inflammatory agent in vivo. In order to measure the effect of CBZ‐phe‐met, one needs a repeat‐able, quantitative, easily obtainable standard measurement of the edema formation. In this study, a caliper designed for measuring soft materials was used to evaluate the edema, induced by croton oil on rabbit ears, as well as the effects of CBZ‐phe‐met.Methods: The model used in this study was croton‐induced inflammation on rabbit ears. A caliper for measuring soft materials (European standard DIN 863 part 3, manufactured by TESA Ltd., Renens, Switzerland) was used to evaluate the edema, which is part of the inflammatory effect. The action of CBZ‐phe‐met and two other anti‐inflammatory agents; hydrocortisone and Na‐ibuprofen, were compared.Results: CBZ‐phe‐met 1‐5% was found to reduce the edema on rabbit ears induced by croton oil by 15 to 93%. 5% CBZ‐phe‐met was found to be as effective as 5% Na‐ibuprofen and 0.1% hydrocortisone.Conclusion: The caliper for soft materials was found to be suitable for measuring the edema induced by croton‐oil, as well as the reducing edema due to anti‐inflammatory treatment. It was also found that CBZ‐phe‐met is a potent topical anti‐inflammatory agent in the croton‐oil‐induced inflammatory model. This may indicate a new approach in the treatment of inflammation.
Visual scoring and laser Doppler perfusion imaging of skin irritancy induced by different nicotine patches
Authors: Krogstad Anne‐Lene , Pegenius Göran , Elam Mikael 
Published: October 2006

Background/aims: Local skin reactions are the most common reason for discontinuation of transdermal nicotine replacement therapy in smoking cessation programs. The aims of the present study were (1) to quantify the intensity of skin reactions induced by different types of nicotine patches and (2) to compare the clinical evaluation of skin erythema using visual scores with independently performed quantitative estimates of skin perfusion.Methods: Thirty‐three subjects were included in the study, each receiving 2 different types of nicotine patches (Nicotinell and Nicorette) and 1 type of placebo patch (Nicorette), placed ventrally on the upper arms according to a randomized protocol. Patches were removed after 24 h (Nicotinell) and 16 h (Nicorette), respectively, according to recommended application times. Visual scoring and laser Doppler perfusion imaging were performed 45 min after removal of patches, in a randomized order.Results: Nicotinell patches induced the highest cumulative clinical score for skin irritancy. All 3 investigated patches gave rise to a slight but significant skin perfusion increase and individual visual scores and perfusion data correlated.Conclusion The degree of skin irritancy and underlying perfusion increase induced by 1 daily maintenance dose of transdermal nicotine via a patch is low, but differs between patch types.
Sensitivity of cutometer data to stratum corneum hydration level
Authors: Murray B. C. , Wickett R. R. 
Published: October 2006

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.
High‐frequency conductance measurement of the skin surface hydration state of dry skin using a new probe studded with needle‐form electrodes (MT‐8C)
Authors: Sasai Shu , Zhen Ya‐Xian , Tagami Hachiro 
Published: October 2006

Background/aims: When high‐frequency conductance measurements are performed on dry scaly skin such as atopic xerosis, senile xerosis or psoriasis, the values recorded with a flat surfaced ordinary probe tend to be lower, indicating a reduced hydration state, than the actual one, because the rough and firm skin surface prevents close contact with the hard and flat surface of the applied probe.Methods: We evaluated the usefulness of an MT‐8C probe (Measurement Technologies Cincinnati, USA), whose skin‐attaching portion is studded with 8 needle‐like electrodes instead of a flat surfaced type, for measurments on dry skin.Results/conclusions: The MT‐8C probe yielded conductance values slightly higher than those recorded with the flat surfaced probe attached to Skicon in measuring the hydration state of moderately dry skin surface such as atopic xerosis and senile xerosis. It seems to be comparable or more sensitive than the capacitance recording with the Corneometer. The recorded values obtained with the MT‐8C probe showed more variations than the latter because of its higher sensitivity and much smaller contact area, that makes it difficult to touch to the same spots repeatedly. No such a difference was observed on severely dry skin and thickly scaly psoriatic lesions.