bluuebunny/crossref_metadata_2025 huggingface dataset:
Color analysis of nevus of Ota for evaluation of treatment with a Q‐switched alexandrite laser
Authors: Miyamoto Hiroshi , Takiwaki Hirotsugu , Yamano Masahiro , Ahsan Kamrul , Nakanishi Hideki
Published: October 2006

Background/aims:

The Q‐switched alexandrite laser shows excellent results in treating nevi of Ota. This study sought to examine the utility of color monitoring of the lesion for quantifying the efficacy of laser treatment.

Methods:

Lesion images were obtained from 12 patients using a video microscope before and after a series of laser treatments. The RGB color data in a 50 mm2 area of the images were converted into coordinates of three color systems and compared with clinical evaluation.

Results:

On three coordinates representing the brightness of skin color (the intensity, the L* and the melanin index), there were significant differences between data obtained before and after treatment (P<0.01), in accord with clinical impressions. Darker lesions tended to show more improvement. Coordinates based on chromaticity were less useful for evaluation of treatment.

Conclusions:

Color analysis of nevi of Ota is useful for quantifying efficacy of laser treatment, especially when assessed in a small area of the lesion.
Pilot study using high‐frequency diagnostic ultrasound to assess surgical wounds in renal transplant patients
Authors: Calvin M. , Modarai B. , Young S. R. , Koffman G. , Dyson M.
Published: October 2006

Background:

The majority of renal transplant patients will sustain at least one acute rejection episode during the first 4 months, following transplantation. Clinical rejection is rarely an all‐or‐nothing reaction, and the first episode seldom progresses to complete renal destruction. The functional changes induced by rejection appear to be in large part reversible; therefore the recognition and treatment of the rejection episode, before the development of severe renal damage, are of extreme importance.

Methods:

This pilot study describes a technique of non‐invasive wound assessment used to monitor 14 transplant patients, over a 3 week post‐operative period. The technique involved the use of 20 MHz diagnostic ultrasound, in conjunction with fractal image analysis. Ultrasound scans of both wounded and adjacent uninjured tissue were taken 5, 7, 11, 14 and 21 days post‐surgery.

Results:

When patients were divided into those who experienced allograft rejection and those who did not, a distinct trend appeared. In those who did not reject, the fractal signature of the wound progressed towards that of normal tissue in a linear fashion. In patients that did reject, the fractal signature initially progressed towards normal until day 11, then changed direction moving away from normal, between days 11 and 14. The patients experiencing allograft rejection were clinically diagnosed around a mean time of 14 days post‐surgery. It is therefore possible that this shift in fractal signature may correlate with graft rejection.

Conclusion:

The results of this pilot study indicate that high frequency diagnostic ultrasound, coupled with appropriate image analysis, may be a useful adjunct to renal function assessment.
Phosphorus metabolites in human skin and muscle obtained by phosphorus‐31 magnetic resonance spectroscopy
Authors: Wright A. C. , Bohning D. E. , Spicer K. M.
Published: October 2006

Background/aims:

Characterization of skin phosphometabol‐ism in vivo by non‐invasive magnetic resonance spectroscopy (MRS) might allow assessment of ischemic or irradiative damage.

Methods:

Based on a study of 17 healthy volunteers, we present statistical analyses for intra‐ and inter‐tissue metabolite concentration ratios, as well as for pH and [Mg2+].

Results:

Results contrasted steady‐state energy metabolism in skin and muscle, showing lower phosphocreatine/ATP, higher percentage of inorganic phosphate, phosphodiesters and phos‐phomonoesters, and higher pH and [Mg2+] in skin than in muscle.

Conclusion:

Results were consistent with known skin physiology and structure and suggested an inverse relationship between skin phosphodiester levels and melanin.
Allergic contact reactions in the skin assessed by electrical impedance – a pilot study
Authors: Nicander Ingrid , Ollmar Stig , Rozell Barbro Lundh , Emtestam Lennart
Published: October 2006

Background/aims:

In our previous studies of the electrical impedance of the skin, we formulated a set of physical indices that could be used to distinguish between the cutaneous effects produced by different chemical irritants. We now describe an investigation of allergic contact reactions, using the same set of impedance indices for characterization.

Methods:

Skin reactions were induced in the forearm of eight female patients who were allergic to nickel by exposure to nickel sulphate in petrolatum at various concentrations. The responses were evaluated by measurements of electrical impedance and transepidermal water loss, as well as by visual scoring and biopsy. Normal skin was used for controls.

Results:

Different degrees of allergic contact reactions were produced, and the changes in value of the impedance indices were found to follow a particular pattern. This pattern diverged markedly from that obtained in controls, and the differences were statistically significant.

Conclusions:

Our results suggest that, by the application of a technique based on electrical impedance, it will be possible to characterize allergic skin reactions.
Irritancy testing of sodium laurate and other anionic detergents using an open exposure model
Authors: Tupker R. A. , Vermeulen K. , Fidler V. , Coenraads P. J.
Published: October 2006

Background/aims:

The irritant potency of soap (sodium laurate, LAU) as opposed to other anionic detergents is not uniformly agreed upon. The aim of the study was to compare the irritancy of sodium laurate with that of sodium laurylsulphate (SLS), sodium cocoyl isethionate and disodium lauryl 3‐ethoxysulphosuc‐cinate by means of a 4‐day repeated open exposure model in order to achieve a more realistic mimicry of daily practice.

Methods:

The effects of the exposures were evaluated by: a) number of fulfilled exposures, b) visual score after exposures, and c) transepidermal water loss (TEWL) after exposures.

Results:

In the majority of subjects, exposure to LAU had to be stopped because of burning sensations, erythema and/or scaling. The number of fulfilled exposures to LAU was lower than that of SLS. The other agents were tolerated very well. These less irritative agents had much lower visual scores and TEWL values after the repeated exposures compared with LAU and SLS.

Conclusions:

The explanation for the irritant nature of LAU in the present study might be the type of alkyl chain length distribution. Its 12‐carbon chain content was ≤ 99%, and this agent can therefore be designated as pure sodium laurate. The same holds true for SLS. In daily practice, however, soap is a mixture of different – less irritant – chain lengths. Therefore, these findings cannot be extrapolated to commercially available soap bars.
Does lipid sampling with the Sebutape technique disturb the skin physiology?
Authors: Clarys P. , Lambrecht R. , Barel A. O.
Published: October 2006

Background/aims:

Lipid sampling with the Sebutape technique takes at least 1 h in order to obtain a representative follicular pattern. Subsequent morphometric analysis reveals different parameters on the sebum excretion. However, application of Sebutape may disturb the normal skin physiology, and hence sebum excretion, due to an occlusive effect. The aim of the present study was to evaluate whether collection of skin surface lipids with Sebutape influences skin parameters such as TEWL, skin temperature and stratum corneum hydration.

Methods:

On the forehead, a comparison was made between skin sites covered with a Sebutape and contralateral control sites. Prior to removal of the Sebutape, skin temperature under the tape was measured. Immediately after removal of the tape, TEWL and skin capacitance were estimated. The same parameters were determined on the control sites. Furthermore, a comparison was made on the forearms between the occlusion effect of Sebutape application and a complete occlusion with a plastic tape. Hydration of the skin was measured as function of time after removal of both occlusive applications.

Results:

We detected only a very weak influence of Sebutape application on TEWL and skin hydration. Skin temperature was not affected. A significant difference was detected between the application of Sebutape and the application of a plastic occlusion.

Conclusions:

Lipid sampling with Sebutape has only minor or no influence on the skin physiology as demonstrated by TEWL, skin temperature and stratum corneum capacitance measurements.
A refined method to evaluate diapers for effectiveness in reducing skin hydration using the adult forearm
Authors: Akin Frank J. , Lemmen Jac T. , Bozarth Dena L. , Garofalo Martin J. , Grove Gary L.
Published: October 2006

Background/aims:

Excessive skin hydration resulting from wet undergarments is a major cause of diaper rash in children and contributes to severe dermatitis in incontinent adults. Advancements in absorbent technology have led to diapers and incontinent garments that not only absorb urine, but also transfer it to different regions, and lock it away from the skin. The purpose of the present study was to develop a reliable method to assess the effectiveness of absorbent articles in mitigating skin hydration.

Methods:

Disposable diapers with different absorbent structures were wrapped around the forearms of adult volunteers, loaded with urine substitute, and held in place for 1 h. Hydration of the volar region was measured by evaporimetry and compared with that of skin in the diaper region of children who had worn control loaded diapers in the usual way. The amount of fluid retained in various diaper layers and in the superabsorbent polymer core was measured.

Conclusions:

Evaporative water loss measurement on adult forearms was shown to be a reliable test for comparing the effectiveness of absorbent articles in preventing excessive skin hydration provided that 1) the complete garment was used and 2) fluid was loaded in a manner that simulated normal urination. Skin on adult forearms and skin in the diaper region of children were concordant in their response to wet diapers. Skin wetness was directly related to the amount of liquid retained in absorbent layers close to the skin.
High resolution laser Doppler perfusion imaging for the investigation of blood circulatory changes after microdialysis probe insertion
Authors: Lindén Maria , Wårdell Karin , Andersson Thomas , Anderson Chris
Published: October 2006

Background/aim:

Cutaneous microdialysis enables in vivo sampling of substances in the extracellular space in human skin. It is usual to allow an equilibration time to elapse after tissue trauma caused by probe insertion. One of the prerequisites for correct interpretation of data is detailed knowledge of the effect of insertion and presence of the probe in the skin, especially in the tissue closest to the membrane.

Methods:

Laser Doppler perfusion imaging was used to investigate the time required for blood perfusion to return to near normal levels after probe insertion. The standard system was used in parallel with a high resolution system. The latter gave 3600 measurement sites in an area of 2 cm × 2 cm and thus enabled a detailed study of circulatory changes immediately around the membrane. Perfusion levels prior to probe insertion as well as the perfusion response to probe insertion were recorded by both systems.

Results:

In agreement with previous findings, the perfusion levels were found to return to near normal levels within 60 min. Individual variations were, however, seen. High resolution laser Doppler perfusion imaging provided detailed visualisation of these variations both spatially and over time.

Conclusions:

High resolution laser Doppler perfusion imaging is superior to standard laser Doppler perfusion imaging in detailed visualisation of the variations in skin blood perfusion after microdialysis probe insertion. The individual variations seen can be of importance in the interpretation of microdialysis data.
A comparison between a tristimulus colorimeter (Minolta ChromaMeter CR‐200) and two spectrophotometers (Minolta Spectrophotometer CM‐508i and CM‐2002). Quantification of UV‐B induced erythema in a hairless guinea pig model
Authors: Fullerton A. , Keiding J.
Published: October 2006

Background/aims:

A comparison was made between a tristimulus colorimeter (Minolta ChromaMeter CR 200) and two spectrophotometers (Minolta CM‐508i and CM‐2002). The object was to compare skin colour data in the CIE 1976 L*a*d*colour space system obtained with the different instruments after UV‐B exposure.

Methods:

Guinea pigs were exposed on their dorsal trunk with UV‐B light for different time periods. Skin colour in the L*a*b* system was measured 6 and 24 h after exposure.

Results:

Reproducible and objective measurements expressed in the CIE system were obtained with all three instruments. A strong correlation was found between the Minolta Chromameter CR200 and each of the two spectrophotometers. However, absolute values found with the Minolta ChromaMeter CR 200, especially for b*, differed from values obtained with the two spectrophotometers.

Conclusions:

The instruments were, despite minor inter‐instrumental variation, suited for objective evaluation of erythema. The spectrophotometers were somewhat cumbersome to use due to their heavy weight and difficulties in positioning within the test sites; the Minolta CromaMeter CR200 (or later versions) is thus preferable for simple routine measurements. Use of the spectophotometers appears only indicated where specific information about skin pigments or photoactive substances relative to wavelength is needed.
Microwave corneosurfametry: a minute assessment of the skin compatibility of surfactant‐containing products
Authors: Goffin Véronique , Piérard‐Franchimont Claudine , Piérard Gérald E.
Published: October 2006

Background/aims:

Surfactants may elicit several undesirable effects on the skin. The stratum corneum is one of the targets showing primary changes after a short contact with detergents. Corneosurfametry was introduced as an ex vivo bioassay to assess the interaction and compatibility of surfactants with human stratum corneum. The present work introduces a variant of the regular corneosurfametry test.

Method:

Microwaving set at 750 W for 30 s was used to shorten the duration of the technical procedure and to allow the rating of neat surfactant‐containing products. The color of samples (L.* and Chroma C*) was measured to derive the colorimetric index of mildness (CIM), the values of which rise from 0 to 70 with increasing surfactant mildness toward human stratum corneum. Data were compared with standard corneosurfametry performed at 20 and 40°C.

Results:

Data indicate that increasing the temperature of the test solutions and microwaving alter the CIM values of most surfactants. Only the most gentle products are little affected. An overall good correlation exists between the regular and microwave corneosurfametry data.

Conclusions:

Microwave corneosurfametry is a new sensitive tool for predicting skin compatibility of surfactants.
Mild and below threshold skin responses to sodium lauryl sulphate assessed by depth controlled electrical impedance
Authors: Nicander Ingrid , Ollmar Stig
Published: October 2006

Background/aims:

There is a need for objective and noninvasive methods to quantify and classify weak reactions in the skin. We have explored the capacity of the electrical impedance technique to evaluate mild irritant skin reactions and responses below the clinical threshold by using low concentrations of sodium lauryl sulphate.

Methods:

Twenty‐one healthy subjects were patch tested with 0.004, 0.02, 0.1 and 0.5% sodium lauryl sulphate on both volar forearms. An unoccluded area was used as a reference site. Values were recorded before application and 24 h after removal of the chambers. The magnitude and phase of electrical impedance were measured in the frequency range 1 kHz to 1 MHz at five depth settings. Four indices were devised from the impedance data, and the values obtained were statistically analysed.

Results:

Between day 1 and day 3, statistically significant differences were found from the concentration of 0.02%, and the significance level increased from depth 1 to depth 5.

Conclusion:

Our results confirm that the electrical impedance method is a sensitive technique for detection of macroscopically negative responses induced by sodium lauryl sulphate, and that depth selection can be used to optimise the signal‐to‐noise ratio.
Protective effects of topically applied CO2‐impregnated water
Authors: Bock M. , Schwanitz H. J.
Published: October 2006

Background/aims: The‘positive effect’of CO2‐impregnated water (mechanical process of producing carbonated therapeutic waters for medical use) on the skin of the hands was reported by 76% of 107 users questioned. The present study intends to evaluate this effect by using bioengeneering methods.

Methods: In 20 healthy volunteers, mild to moderate irritation was induced on both hands using a standardised washing procedure. One hand was rinsed with CO2‐impregnated water (carbonic acid) once daily for 1 min, the other with tap water as the control. Baseline values and values 30 min after application were recorded by measuring transepidermal water loss (TEWL), skin humidity (SH), microcirculation of the blood (BF) and skin surface pH. Wilcoxon's signed rank test was used for statistical analysis; P‐values of less than 0.05 were considered to be significant.

Results: Baseline TEWL, BF and pH tended to be lower (in some cases significantly lower) in the test regions treated with carbonic acid, whereas baseline SH tended to be higher (in some cases significantly higher). TEWL and pH were significantly lower for the side treated with CO2 30 min after application, whereas in some cases SH was significantly higher compared with the control side. Visual comparison revealed a lesser degree of irritation for the region treated with CO2 in comparison with the control side.

Conclusions: The results show that the skin physiology parameters of irritated skin are favourably influenced by the topical application of CO2‐impregnated water. Although those test regions treated with carbonic acid did not remain uninfluenced by repeated irritation in clinical comparisons, the irritation was more intensive in the test regions treated with fresh water.
Quantitative assessment of epidermal Langerhans cells using automated image analysis
Authors: Smolle Josef , Hofmann‐Wellenhof Rainer
Published: October 2006

Background/aims: Langerhans cells play a central role In the skin immune system. Quantitative changes have been observed in a variety of dermatological conditions. This paper presents a user‐independent automated measurement procedure for Langerhans cells in vertical skin sections.

Methods: Frozen sections were stained immunohistochemically with a CD1 monoclonal antibody. Counterstaining was performed with Mayer's hematoxylin. An image analysis procedure was developed, which automatically recognizes the area occupied by the epidermis and the CD1 ‐positive structures, respectively.

Results: The procedure was tested on specimens of normal skin and of chronic cutaneous lupus erythematosus. The results significantly reflect the decrease of Langerhans cells in the latter condition.

Conclusion: The proposed image analysis program facilitates a fully automated measurement of immunohistochemically stained epidermal structures in vertical skin sections.
Contrast enhanced high resolution MRI of cutaneous melanomas using Gd‐DTPA and Gd‐DTPA‐polylysine: experimental results
Authors: Mäurer J. , Knollmann F. D. , Veuskens C. , Ebert W. , Bauer H. , Felix R.
Published: October 2006

Background/aims: An experimental model for the preclinical evaluation of contrast enhancement patterns in melanoma was developed.

Methods: Melanotic and amelanotic tumor cells B16F1 and B16a implanted into murine skin were depicted with magnetic resonance imaging (MRI) at a pixel size of 78×78 urn and 1 mm slice thickness. Tumor signal intensities were evaluated in user defined ROIs (regions of interest). Signal intensity changes were determined from signal intensity‐time curves. Percent enhancement, slope of the signal intensity curve and percent signal intensity increase were also determined. Percent enhancement was calculated: (SIenhanced‐SIpiain)/SIplain× 100 [SI=signal intensity]. The slope of the signal intensity curve was calculated: (SImax‐SIplain)/(SIplain× SImax) × 100 (%/min). Percent signal intensity increase was calculated: (SImax‐SIplai)/SIplain× 100.

Results: Following i.v. administration of Gd‐DTPA and G‐DTPA‐polylysine, all tumors showed pronounced contrast enhancement. Contrast enhancement and the slope of signal intensity to time curves did not distinguish melanotic from amelanotic melanomas (P>0.05).

Conclusions: The animal model presented is well suited for evaluation of contrast enhancement in melanoma by MRI. Contrast enhancement of melanoma in MRI is comparable with the enhancement seen in other tumors.
Magnetic resonance coil for 31P spectroscopy of skin over curved body surfaces
Authors: Bohning D. E. , Pecheny A. P. , Wright A. C. , Spicer K. M.
Published: October 2006

Background/aims: Increasing signal‐to‐noise ratio for skin spectroscopy means increasing area, but increased area usually means resorting to Fourier window techniques to prevent overwhelming muscle contamination. The aim of this work was to develop a simple coil that would allow large areas of skin to be sampled while limiting muscle contamination simply by the coil's geometry.

Methods: The coil design was arrived at by using simulations that were calibrated by phantom tests with prototype units. It was then fabricated by using an etched circuitboard technique and tested on three volunteers for comparison with predicted performance.

Results: The new coil acquires magnetic resonance signals from a 140 cm2 contoured layer of surface tissue with sufficient selectivity that 81% of the signal comes from tissue less than 1.9 mm deep. For skin and fat thicknesses of 1.1 and 3.1 mm, respectively, tending toward a worst case in‐vivo situation, muscle contamination is only 3.3%. With the new coil, in 1 h, it was possible to directly acquire 31P skin spectra comparable to those formerly obtained in 4 h in two separate acquistions that then had to be subtracted to obtain the desired skin spectra.

Conclusion: Increasing the area of skin sampled while maintaining selectivity to limit muscle contamination, relying simply on coil geometry, is practical using a parallel configuration of long narrow strip coils.
Influence of skin area, age and sex on corneometric determinations
Authors: Mussi A. , Carducci M. , D'Agosto G. , Bonifati C. , Fazio M. , Ameglio F.
Published: October 2006

Background/aims: Comeometry represents a useful tool for dermatologists, even though several interfering variables may reduce its reliability level. The present study describes some of the methodological points that optimize corneometric measurements and analyzes the interference due to the skin area selected, the age and the sex of the individuals observed.

Results: The results show that skin areas may present significantly different corneometric values. In addition, a significant correlation of the corneometric values at most of the sites was observed independently of the sun‐exposed site.

Conclusions: The corneometric values were clearly age dependent and sex independent. Measurements were obtained from eight different body areas (two of them were symmetric and presented superimposable results). The volar forearm appears to be the area least influenced by the patients’age and presents the lowest correlation coefficients with other skin sites.
EIectrical impedance and transepidermal water loss of healthy human skin under different conditions
Authors: Hildebrandt Diana , Ziegler Kathrin , Wollina Uwe
Published: October 2006

Background/aims: The skin barrier function is a multidimensional quality, which can be defined by a combination of noninvasive measurements, including EIectrical impedance (EI) and transepidermal water loss (TEWL).

Methods: TEWL and EI were determined on in five different areas of the body in 25 healthy volunteers. The effects of hydration (a 15 min water bath, a 1 h occlusion and application of an oil‐in‐water emulsion combined with occlusion) were measured on the volar forearm.

Results: EI was highest in the axillary region, followed by the cheek, spinal region, presternal area and upper arm. TEWL was highest in the axillary region, followed by the cheek. Lowest levels were detected in the spinal region, the presternal region and the upper arm. The water bath increased EI but not TEWL. After 1 h occlusion TEWL was not increased and EI decreased, which corresponds to stratum corneum hydration. After a single application of an oil‐in‐water emulsion, we observed a reduction of EI and an increase of TEWL. The simultaneous use of occlusion and application of an emulsion led to the most significant reduction of EI. TEWL was increased during the following 30 min.

Conclusions: EI and TEWL show a topological variability. Acute hydration increased EI but occlusion and/or moisturizing decreased EI. Acute hydration and occlusion alone did not significantly affect TEWL, but moisturizing in combination caused a longer lasting TEWL increase. To examine the stratum corneum function, the use of different noninvasive techniques seem to provide more complex information.
The fasciitis‐panniculitis syndromes: histomorphometric assessment of the inflammatory and sclerosing processes affecting the subcutaneous and fascial tissues
Authors: Sabo Edmund , Naschitz Jochanan E. , Misselevich Ines , Boss Jochanan H.
Published: October 2006

Background/aims :The fasciitis‐panniculitis syndromes include several disorders characterized by skin induration due to fibrotic thickening of the septa of the subcutis and muscular fascia associated with chronic inflammation. Representative of the idiopathic form, eosinophilic fasciitis, is the prototype of the fasciitis‐panniculitis syndromes. Secondary forms of the syndromes are causally related to a variety of diseases, such as infections, circulatory disorders, physical injuries and neoplasms.

Methods: Histological sections of 10 idiopathic and 20 secondary cases of the fasciitis‐panniculitis syndromes were assessed by means of computer‐assisted image analysis. The percent of fibrous tissue, referred to as “extent of fibrosis”, and the number of lymphocytes, macrophages, eosinophils, plasma cells, and mast cells within the subcutaneous‐fascial complex were assessed.

Results: The “extent of fibrosis” varied from 1% to 2% in the control cases and from 4% to 98% in the index cases. The number of inflammatory cells per high power field varied from 0 to 33 in the control cases and from 9 to 323 in the index cases.

Conclusions: There is a direct and positive correlation between the “extent of fibrosis” and the number of inflammatory cells. The “extent of fibrosis” and intensity of the inflammatory infiltration do not correlate with the nature of the underlying diseases, the patients’demographic data, the anatomic location of the subcutaneous induration or the duration of the lesion. It is suggested that the fasciitis‐panniculitis syndromes are the morphological expression of a chronic, relapsing, inflammatory‐sclerosing reaction pattern that is essentially identical in the idiopathic and the secondary forms of the disorder.
Comparison between visual score and erythema index (DermaSpectrometer) in evaluation of allergic patch tests
Authors: Held Elisabeth , Lorentzen Henrik , Agner Tove , Menné Torkil
Published: October 2006

Background/aims: During the last decade several new bioengineering methods have been proposed for evaluation of patch test reactions in a more objective manner. The aim of the present study was to investigate the usefulness of erythema index (DermaSpectrometer) in a clinical setting, i.e., reading of allergic patch tests.

Methods: Twenty patients with known allergy to formaldehyde participated in the study. Each patient had patch tests for 2 days with formaldehyde solutions from 0 to 10,000 p.p.m. applied. Clinical reading of the test sites and measurement of the erythema index by the DermaSpectrometer were done 24 h after removal. A control group of 20 volunteers with no allergy to formaldehyde were tested in a similar way.

Results: Erythema indices were significantly higher for visually rated positive patch tests than for negative tests (P<0.05). The single categories of visually positive reactions (+?, +, ++, +++) could not be unambiguously separated by the DermaSpectrometer. The correlation between clinical readings and the formaldehyde concentration (Spearman's rank correlation coefficient, r=0.60) was higher than between DermaSpectrometer readings and the formaldehyde concentration (r=0.35).

Conclusion: In a dilution series of formaldehyde patch testing, readings from a DermaSpectrometer were not found to give better information than visual readings.
Effect of topical application of antioxidants and free radical scavengers on protection of hairless mouse skin exposed to chronic doses of ultraviolet B
Authors: Muizzuddin Neelam , Shakoori Abdul Rauf , Marenus Kenneth D.
Published: October 2006

Background/aims: Within the past three decades, there has emerged a greater awareness of the molecular effects of solar rays especially ultraviolet radiation (UV‐R), to the extent that the harmful effects of solar radiation are recognized not only by molecular biologists and physicians, but also by the general public (1). Various sunscreen molecules that effectively block the UVB component of the sun are available; however, a large part of Western populations elicits adverse reactions against chemical sunscreens (2). This study was designed to observe the protective effect of antioxidants against the damaging effects of chronic UVB exposure of skin in an attempt to introduce antioxidants and free radical scavengers as topical sun protective agents.

Methods: Jackson hairless mice were exposed to suberythemal doses of UVB, three times a week, and topically treated with a cream containing the anti‐oxidants vitamin E, butylated hydroxy‐toluene, nordihydroguaradinic acid and vitamin C.

Results: Treatment with vehicle alone along with UVB exposure resulted in an increase in epidermal thickness showing a 38%, 77% and 112% increase after 4 weeks, 8 weeks and 12 weeks, respectively. Chronic UVB exposed skin treated with the material containing free radical scavengers and antioxidants mix (AO mix) exhibited 39%, 73% and 124% thicker epidermis than the un‐treated control after, respectively, 4 weeks, 8 weeks and 12 weeks of treatment. The vehicle did not appear to protect skin against UV irradiation, since there appeared to be more (16%) sunburn cells in vehicle treated skin than the untreated, UV exposed skin after 4 weeks of treatment. After 8 weeks and 12 weeks, there were 33% and 36% less sunburn cells in the vehicle treated skin than the untreated, UV exposed skin. The antioxidant mix was significantly effective (P=<0.001) in protecting against UVB irradiation, having 63%, 71 % and 79% fewer sunburn cells than the untreated, UV exposed skin after 4 weeks, 8 weeks and 12 weeks of treatment, respectively.

Conclusion: Data from these studies suggest that low level chronic exposures to UV can lead to alteration of the skin, like epidermal thickening and appearance of sunburn cells. The data also indicates that a mix of common antioxidants and free radical scavengers are photoprotective against chronic skin damage in the hairless mouse skin model.
Tensile properties and contours of aging facial skin. A controlled double‐blind comparative study of the effects of retinol, melibiose‐lactose and their association
Authors: Piérard‐Franchimont C. , Castelli D. , Cromphaut I. Van , Bertin C. , Ries G. , Cauwenbergh G. , Piérard G. E.
Published: October 2006

Background/aims: Facial aging is accompanied by modifications in the tensile properties and contours of skin. In the present study we instrumentally assessed and compared the effect of either 0.04% retinol (ROL), 1% melibiose and 4% lactose (ME‐L) and their association (ROL‐ME‐L) to increase the firmness and smoothness of facial skin. A 1 % salicylic acid (SA) emulsion served as a cosmetic product reference.

Methods: A total of 120 women were allocated to four randomized groups of 30 subjects, each group receiving one of the test products or a combination of test products. The tensile properties of facial skin were measured using the Cutometer® on seven occasions during the 12‐week treatment and during a 4‐week post‐treatment phase. Fine lines and wrinkles were assessed on replicas by using image analysis after optical shadowing.

Results: Significant differences in efficacy and lingering activity were observed between products. SA brought the weakest beneficial effects. ROL and ME‐L provided better efficacy on both the tensile properties and contours of skin. They differed slightly according the nature of the biometrological variables. The combination ROL‐ME‐L achieved similar or even better results than the best of its components for each given physical property of skin.

Conclusions: ROL, ME‐L, and ROL‐ME‐L formulations improve physical properties of skin that are impaired by aging. Their activities are notably superior to those of a comparative SA formulation.
Comparative study of five instruments measuring stratum corneum hydration (Corneometer CM 820 and CM 825, Skicon 200, Nova DPM 9003, DermaLab). Part I. In vitro
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 vitro conditions: Corneometer CM 820 and CM 825, Skicon 200, Nova DPM and DermaLab.

Methods: A sorption‐desorption test, measurements on different filters and with liquids with different dielectric constants, measurement‐depth analysis and measurements on different agar plates were performed.

Results: Good correlation between the values of the five instruments and μl (sorption test: varying from r= 0.8249 to r= 0.9635) and time (desorption test: correlation varying from r= 0.7615 to r=0.9909) could be demonstrated. A high Spearman correlation coefficient (r) could be proven for dielectric constant (dc)/CM 820 (r=0.9333), dc/CM 825 (r=0.9833) and dc/Nova DPM (r=0.9048). A lower correlation or no correlation was found for dc/DermaLab (r=0.8469; P=0.023) and dc/Skicon 200 (r=0.9000; P=0.083).

Conclusions: For each of the five instruments, the electrical field of measurement can be assumed to cover the following depths: CM 820, between 30 and 45 μm; CM 825, around or less than 15 μm; Skicon 200, less than 15 μm; Nova DPM, between 45 and 60 μm; DermaLab, around or less than 15 nm.
Measuring depth depends on frequency in electrical skin impedance measurements
Authors: Martinsen ØSrjan G. , Grimnes Sverre , Haug Erlend
Published: October 2006

Background/aims: Multi‐frequency electrical measurements in vivo on stratum corneum are frequently reported in the literature. It is well known that the measured volume of skin is dependent on measuring frequency, and we wanted to investigate to what extent viable skin influences the measured impedance as a function of frequency.

Methods: Finite element modelling (FEM) was used to investigate the current and potential distribution in the skin when measuring impedance with two concentric surface electrodes.

Results: The study showed that the impedance measured reflects mainly the stratum corneum at low frequencies, in this case below 1 kHz, and that the viable skin dominates at higher frequencies.

Conclusion: It is concluded that a multi‐frequency measurement on isolated stratum corneum is not possible in vivo with conventional techniques, except within a very narrow and low frequency range.
Digital videomicroscopy with image analysis and automatic classification as an aid for diagnosis of Spitz nevus
Authors: Pellacani Giovanni , Martini Mia , Seidenari Stefania
Published: October 2006

Aims: The aims of the study were: 1) to evaluate features that refer to digital images of ESC (epithelioid and/or spindle cell) nevi recorded by means of a videomicroscope and to compare them to those that refer to nevi and melanomas; 2) to assess the efficacy of an automatic classifier for the differentiation between ESC nevi and melanomas.

Methods: Prior to biopsy, 29 ESC nevus images were recorded by means of a digital videomicroscope. All digital images were analyzed with software that calculates different parameters that relate to the geometry, color distribution and internal pattern of the lesion. Digital parameters that refer to ESC nevi and other PSLs (pigmented skin lesions: nevi and melanomas) were compared. Values that refer to parameters calculated on ESC nevi and melanomas acquired with the same magnification underwent elaboration by means of multivariate discriminant analysis, enabling a distinction among the groups. Finally, the diagnosis obtained by the automatic classifier was compared to the ones obtained by the naked eye and by videomicroscopic observation.

Results: Significant differences between values that refer to ESC nevi and other PSL (nevi and melanomas) were noticed for most digital parameters. Automatic classification enabled the distinction among ESC nevi and melanomas with a 100% sensitivity and a 100% and 86% specificity employing the 50‐ and 20‐fold magnification, respectively.

Conclusion: Digital analysis of videomicroscopic images by means of dedicated software enables an objective characterization of morphological features. Values obtained by image analysis may be immediately examined by the automatic classifier, in order to provide an aid to clinical diagnosis.
African Swine Fever Virus Causes Microtubule-Dependent Dispersal of the
trans
-Golgi Network and Slows Delivery of Membrane Protein to the PlasmaMembrane
Authors: Netherton Christopher L. , McCrossan Mari-Clare , Denyer Michael , Ponnambalam Sreenivasan , Armstrong John , Takamatsu Haru-Hisa , Wileman Thomas E.
Published: October 2006

Viral
interference with secretory cargo is a common mechanism for pathogen
immune evasion. Selective down regulation of critical immune system
molecules such as major histocompatibility complex (MHC) proteins
enables pathogens to mask themselves from their host. African swine
fever virus (ASFV) disrupts the
trans
-Golgi network (TGN) by
altering the localization of TGN46, an organelle marker for the distal
secretory pathway. Reorganization of membrane transport components may
provide a mechanism whereby ASFV can disrupt the correct secretion
and/or cell surface expression of host proteins. In the study reported
here, we used the tsO45 temperature-sensitive mutant of the G protein
of vesicular stomatitis virus to show that ASFV significantly reduces
the rate at which the protein is delivered to the plasma membrane. This
is linked to a general reorganization of the secretory pathway during
infection and a specific, microtubule-dependent disruption of
structural components of the TGN. Golgin p230 and TGN46 are separated
into distinct vesicles, whereupon TGN46 is depleted. These data suggest
that disruption of the TGN by ASFV can slow membrane traffic during
viral infection. This may be functionally important because infection
of macrophages with virulent isolates of ASFV increased the expression
of MHC class I genes, but there was no parallel increase in MHC class I
molecule delivery to the plasma
membrane.
Hantavirus N Protein Exhibits Genus-Specific Recognition of the Viral RNA Panhandle
Authors: Mir M. A. , Brown B. , Hjelle B. , Duran W. A. , Panganiban A. T.
Published: October 2006

A key genomic characteristic that helps define
Hantavirus
as a genus of the family
Bunyaviridae
is the presence of distinctive terminal complementary nucleotides that promote the folding of the viral genomic segments into “panhandle” hairpin structures. The hantavirus nucleocapsid protein (N protein), which is encoded by the smallest of the three negative-sense genomic RNA segments, undergoes in vivo and in vitro trimerization. Trimeric hantavirus N protein specifically recognizes the panhandle structure formed by complementary base sequence of 5′ and 3′ ends of viral genomic RNA. N protein trimers from the Andes, Puumala, Prospect Hill, Seoul, and Sin Nombre viruses recognize their individual homologous panhandles as well as other hantavirus panhandles with high affinity. In contrast, these hantavirus N proteins bind with markedly reduced affinity to the panhandles from the genera
Bunyavirus
,
Tospovirus
, and
Phlebovirus
or
Nairovirus
. Interactions between most hantavirus N and heterologous hantavirus viral RNA panhandles are mediated by the nine terminal conserved nucleotides of the panhandle, whereas Sin Nombre virus N requires the first 23 nucleotides for high-affinity binding. Trimeric hantavirus N complexes undergo a prominent conformational change while interacting with panhandles from members of the genus
Hantavirus
but not while interacting with panhandles from viruses of other genera of the family
Bunyaviridae
. These data indicate that high-affinity interactions between trimeric N and hantavirus panhandles are conserved within the genus
Hantavirus
.
Multivalent Sequence Recognition by Epstein-Barr Virus Zta Requires Cysteine 171 and an Extension of the Canonical B-ZIP Domain
Authors: Wang Pu , Day Latasha , Lieberman Paul M.
Published: October 2006

Epstein-Barr virus (EBV) immediate-early protein Zta is a member of the basic-leucine zipper (B-ZIP) family of DNA binding proteins that has an unusual capacity to recognize multiple DNA recognition sites, including AP-1 and C/EBP binding sites. To better understand the structure and function of Zta, we have mutagenized cysteine residues within or adjacent to the B-ZIP domain. We found that serine substitution for cysteine 171 (C171S), which lies outside and amino terminal to the B-ZIP basic region, completely abrogates Zta capacity to initiate lytic cycle replication. C171S disrupted Zta transcription activation function of several EBV lytic cycle promoters, including the BMRF1 gene (EA-D) and the other lytic activator, Rta. Overexpression of Rta could not rescue the C171S defect for transcription reactivation or viral DNA replication. Zta C171S was defective for binding to these promoters in vivo, as measured by chromatin immunoprecipitation assay. Purified Zta C171S bound AP-1 sites similar to wild-type Zta, but it was incapable of binding several degenerate Zta sites, including a consensus C/EBP site. Zta truncation mutations reveal that residues N terminal to the B-ZIP (amino acids 156 to 178) confer C/EBP binding capacity to the otherwise AP-1-restricted DNA recognition function. Comparison among viral orthologues of Zta suggest that a conserved N-terminal extension of the consensus B-ZIP domain is required for this multivalent DNA recognition capacity of Zta and is essential for viral reactivation.
Global Structural Changes in Hepatitis B Virus Capsids Induced by the Assembly Effector HAP1
Authors: Bourne Christina R. , Finn M. G. , Zlotnick Adam
Published: October 2006

Hepatitis B virus (HBV) is a leading cause of liver disease and hepatocellular carcinoma; over 400 million people are chronically infected with HBV. Specific anti-HBV treatments, like most antivirals, target enzymes that are similar to host proteins. Virus capsid protein has no human homolog, making its assembly a promising but undeveloped therapeutic target. HAP1 [methyl 4-(2-chloro-4-fluorophenyl)-6-methyl-2-(pyridin-2-yl)-1,4-dihydropyrimidine-5-carboxylate], a heteroaryldihydropyrimidine, is a potent HBV capsid assembly activator and misdirector. Knowledge of the structural basis for this activity would directly benefit the development of capsid-targeting therapeutic strategies. This report details the crystal structures of icosahedral HBV capsids with and without HAP1. We show that HAP1 leads to global structural changes by movements of subunits as connected rigid bodies. The observed movements cause the fivefold vertices to protrude from the liganded capsid, the threefold vertices to open, and the quasi-sixfold vertices to flatten, explaining the effects of HAP1 on assembled capsids and on the assembly process. We have identified a likely HAP1-binding site that bridges elements of secondary structure within a capsid-bound monomer, offering explanation for assembly activation. This site also interferes with interactions between capsid proteins, leading to quaternary changes and presumably assembly misdirection. These results demonstrate the plasticity of HBV capsids and the molecular basis for a tenable antiviral strategy.
Epstein-Barr Virus Represses the FoxO1 Transcription Factor through Latent Membrane Protein 1 and Latent Membrane Protein 2A
Authors: Shore Angharad M. , White Paul C. , Hui Rosaline C.-Y. , Essafi Abdelkader , Lam Eric W.-F. , Rowe Martin , Brennan Paul
Published: October 2006

Epstein-Barr virus (EBV) infection is associated with the development of many B-cell lymphomas, including Burkitt's lymphoma, Hodgkin's lymphoma, and posttransplant lymphoproliferative disease. The virus alters a diverse range of cellular molecules, which leads to B-cell growth and immortalization. This study was initiated to investigate the interplay between EBV and a proapoptotic transcription factor target, FoxO1. In this report, we show that EBV infection of B cells leads to the downregulation of FoxO1 expression by phosphatidylinositol 3-kinase-mediated nuclear export, by inhibition of FoxO1 mRNA expression, and by alteration of posttranslational modifications. This repression directly correlates with the expression of the FoxO1 target gene
Bcl-6
and inversely correlates with the FoxO1-regulated gene
Cyclin D2
. Expression of the EBV genes for latent membrane protein 1 and latent membrane protein 2A decreases FoxO1 expression. Thus, our data elucidate distinct mechanisms for the regulation of the proapoptotic transcription factor FoxO1 by EBV.
Phospholipase A2 Activity-Dependent Stimulation of Ca
2+
Entry by Human Parvovirus B19 Capsid Protein VP1
Authors: Lupescu Adrian , Bock C.-Thomas , Lang Philipp A. , Aberle Susanne , Kaiser Heike , Kandolf Reinhard , Lang Florian
Published: October 2006

Recent reports demonstrated an association of human parvovirus B19 with inflammatory cardiomyopathy (iCMP), which is accompanied by endothelial dysfunction. As intracellular Ca
2+
activity is a key regulator of cell function and participates in mechanisms leading to endothelial dysfunction, the present experiments explored the effects of the B19 capsid proteins VP1 and VP2. A secreted phospholipase A2 (PLA2)-like activity has been located in the VP1 unique region of the B19 minor capsid protein. As PLA2 has recently been shown to activate the store-operated or capacitative Ca
2+
channel I
CRAC
, we analyzed the impact of the viral PLA2 motif on Ca
2+
entry. We cloned the VP1 and VP2 genes isolated from a patient suffering from fatal B19 iCMP into eukaryotic expression vectors. We also generated a B19 replication-competent plasmid to demonstrate PLA2 activity under the control of the complete B19 genome. After the transfection of human endothelial cells (HMEC-1), cytosolic Ca
2+
activity was determined by utilizing Fura-2 fluorescence. VP1 and VP2 expression did not significantly modify basal cytosolic Ca
2+
activity or the decline of cytosolic Ca
2+
activity following the removal of extracellular Ca
2+
. However, expression of VP1 and of the full-length B19 clone, but not of VP2, significantly accelerated the increase of cytosolic Ca
2+
activity following the readdition of extracellular Ca
2+
in the presence of thapsigargin, indicating an activation of I
CRAC.
The effect of VP1 was mimicked by the PLA2 product lysophosphatidylcholine and abolished by an inactivating mutation of the PLA2-encoding region of the VP1 gene. Our observations point to the activation of Ca
2+
entry by VP1 PLA2 activity, an effect likely participating in the pathophysiology of B19 infection.