bluuebunny/crossref_metadata_2025 huggingface dataset:
A Reexamination of Long‐Run PPP: The Case of Canada, the UK, and the US
Authors: Crowder William J.
Published: October 2006

The inherent nonstationarity of the variables has led many researchers to use unit root and cointegration methodologies to analyze the PPP hypothesis. The imposition of proportionality and symmetry restrictions has been a common practice yet no explicit hypothesis tests have been conducted to determine the validity of such restrictions. Few of the studies have dealt with the presence of deterministic trends in the data. This study uses a long span of data and explicitly tests the proportionality and symmetry restrictions implied by PPP. A careful treatment of the role of deterministic trends in the data is also included.
The Cyclical Behavior of Net Exports: Temporary and Persistent Movements
Authors: Phillips Kerk L.
Published: October 2006

This paper explores the empirical relationship of net exports, domestic output, and foreign output. It presents evidence supporting a consumption‐smoothing motive for trade in goods. Classical models of the international macroeconomy typically allow for trade in claims on both home and foreign output. This paper lends empirical support to this setup by showing that highly transitory shocks to output cause net exports from the country experiencing the shock to rise. Persistent shocks have opposite effects—a result consistent with the role persistent shocks play in signaling future investment opportunities.
Vertical Integration and International Predation
Authors: Bernhofen Daniel M.
Published: October 2006

This paper investigates the interrelationship between a firm's incentive to engage in international predatory pricing and its domestic vertical industry ties in the context of the deep‐pockct theory of predation. The deep pocket stems from a vertically integrated firm's ability to shift funds between its upstream and downstream divisions. enabling it to prey on vertically unintegrated upstream competitors. Vertical integration is shown to function as a cause of and a deterrent to foreign predatory behavior.
Sustainable Development and International Distribution: Theory and Application to Rainforests
Authors: Mohr Ernst
Published: October 2006

A situation is analyzed in which two countries negotiate the financing of costs that accrue if one of them switches onto a sustainable development path. The other country's incentive to pay arises as it benefits from the developing country's environmental resources, but at an ever declining rate as long as development remains nonsustainable. In an application to the protection of tropical rainforests it is shown that North to South redistribution of welfare would be substantial, yet the North would still gain enormously in efficiency terms. An explanation is given of why the Rio Conference failed in terms of rainforest protection.
Exchange Rates, Pricing‐ to‐Marke t Strategies, and the Marshall‐Lerner Condition
Authors: Bughin Jacques Rene Jean
Published: October 2006

This paper reexamines the relationship between the Marshall‐Lerner (M‐L) condition and the effects of exchange‐rate movements on the trade balance, by integrating the role of product‐market structure and the related issue of strategic interaction on tradeables prices and international flows.
Do Three Trade Blocs Minimize World Welfare?
Authors: Nitsch Volker
Published: October 2006

Two interesting results have emerged from research on symmetric models that make the analysis of bilateralism tractable. Krugman reported that three trade blocs minimize world welfare. Frankel, Stein, and Wei argued that the formation of continental trading blocs can reduce welfare. This paper shows that these results are not robust. In particular, it is argued that the inclusion of more realistic assumptions into a symmetric model changes the picture considerably. Specifically, if one allows for transportation costs, conventional results are obtained. The phenomenon of three welfare‐minimizing blocs and “super‐natural” blocs disappears.
Avellis syndrome due to borreliosis
Authors: Habek M. , Mubrin Z. , Brinar V. V.
Published: November 2006

Avellis syndrome is a rare form of alternating hemiparesis that is usually because of atherosclerosis. We report a 67‐year‐old man who developed paresthesiae of the left arm, dysphagia and dysphonia. The clinical picture, magnetic resonance imaging and cerebrospinal fluid findings were consistent with Avellis syndrome caused by brain stem arteritis because of late stage Borrelia burgdorferi infection, an extremely unusual aetiology for Avellis syndrome; this may well be the first such instance. It may be unrecognized in elderly patients with other risk factors for cerebrovascular disease.
Decreased cerebral blood flow velocity in apolipoprotein E ɛ4 allele carriers with mild cognitive impairment
Authors: Sun Z.‐W. , Zhu Y.‐X. , Liu H.‐Y. , Liu J. , Zhu X.‐Q. , Zhou J.‐N. , Liu R.‐Y.
Published: November 2006

The aim of this study was to investigate the changes in cerebral blood flow velocity (CBFV) and its relation to apolipoprotein E (apoE) ɛ4 allele in mild cognitive impairment (MCI). Thirty MCI and 30 controls were assessed using Mini‐Mental State Examination (MMSE) and Cambridge Cognitive Examination‐Chinese version (CAMCOG‐C), and then insonated in the anterior (ACA), middle (MCA) and basilar (BA) cerebral arteries using transcranial Doppler ultrasonography. Compared with controls, MCI showed significant decreases in the mean (Vm), systolic (Vs) and diastolic (Vd) CBFV, bilaterally in MCA and ACA (P < 0.05–0.001), but not in BA. Compared with 17 apoE ɛ4 allele non‐carriers, 13 carriers in MCI showed significant CBFV decreases, bilaterally in MCA (P < 0.05–0.001). Our findings, the decreased CBFV in apoE ɛ4 allele carriers with MCI, suggest that a large sample and longitudinal study in CBFV and cognitive changes may have the implications on early diagnosis of Alzheimer's disease.
The forward premium anomaly: statistical artefact or economic puzzle? New evidence from robust tests
Authors: Maynard Alex
Published: November 2006

Abstract Recent literature has questioned statistical inference in predictive regression with persistent regressors, suggesting a possible explanation for puzzles such as the forward premium anomaly. We therefore revisit this puzzle using three alternative econometric methods known to provide reliable inference in the presence of persistent conditioning variables. While they provide less evidence against forward rate unbiasedness than traditional predictive regression tests, we still reject using at least one method for all six currencies. Thus, while the econometric problems inherent in predictive regression likely play a role in this anomaly, we are left with an economic puzzle even after accounting for their influence.
Effect of inversion and ankle bracing on peroneus longus Hoffmann reflex
Authors: Sefton J. M. , Hicks‐Little C. A. , Koceja D. M. , Cordova M. L.
Published: November 2006

This study examined peroneus longus (PL) Hoffmann reflex (H‐reflex) during sudden inversion perturbation of the ankle/foot complex under an ankle brace and non‐brace condition. Ten healthy subjects volunteered. H‐reflexes were tested on the up‐sloping portion of the recruitment curve, utilizing a control trial M‐wave above motor threshold to maintain consistency between subjects and conditions. The PL H/maximum M‐wave (Mmax) ratio was established using the PL H‐reflex and PL Mmax peak‐to‐peak measures. The mean ratio across five trials for each subject under each ankle brace (brace, no brace) and surface (flat, inversion) conditions was utilized for analysis. The 1 × 4 repeated measures ANOVA revealed a significant main effect for treatment condition (P<0.0001). The PL H/Mmax ratio significantly increased during sudden inversion‐no ankle brace condition compared with the flat surface no‐ankle brace condition (P=0.04). Application of an ankle brace had no effect on PL H/Mmax ratio during inversion (P=0.78). During this study PL H/Mmax ratios increased during an inversion perturbation in healthy ankles. This is believed to occur due to heightened sensorimotor demand placed on the nervous system during this motion. Moreover, application of an ankle brace during inversion does not appear to affect PL H/Mmax ratio.
Sports‐related eye injuries: floorball endangers the eyes of young players
Authors: Leivo T. , Puusaari I. , Mäkitie T.
Published: November 2006

The objectives of this study were to determine the distribution of different sports‐related eye injuries and to identify injury types to enable recommendations to be made about the use of protective eyewear. The study population comprises all 565 eye trauma patients examined at the Ophthalmology Emergency Clinic of the Helsinki University Central Hospital over a 6‐month period. Data were collected from patient histories and questionnaires. In addition, three severe floorball eye injury cases are presented. Of the 565 eye traumas, 94 (17%) were sports related. Of these, 42 (45%) were associated with floorball. Countrywide, in Finland, estimated over 300 (+95% CI 228–415) floorball eye injuries occur annually. The mean age of floorball patients was 22 years. The most common finding (55%) in sports injury patients was hyphema. Clinically severe eye injuries during this period accounted for one‐fourth of all cases. During the study period, no eye injury was found in an organized junior ice hockey, where facial protection is mandatory. Floorball is estimated to belong to the highest risk group in sports, and thus, the use of protective eyewear is strongly recommended. We conclude that national floorball federations should make protective eyewear mandatory.
Biomechanical assessment of photodamage
Authors: Piérard G. E. , Kort R. , Letawe C. , Olemans C. , Piérard‐Franchimont C.
Published: October 2006

Background/Aims: Intrinsic aging and photoaging may present different biomechanical properties. Dorsal and volar forearm skin is differently exposed to UV‐light. The object was to derive a cutaneous extrinsic aging score (SEAS) representative of UV aging, i.e. the global photoaging corrected for intrinsic aging.

Methods: The Cutometer SM 474 was used for the measurement of skin mechanical properties. 86 healthy Caucasian women were studied. Dorsal and volar forearm skin was measured.

Results: Age related changes consisting of an overall increase in skin extensibility (Uf) and viscoelastic ratio (Uv/Ue) with decreased biologic elasticity (BE) was observed. Differentials in extensibility (Uf) and viscoelastic ration (Uv/Ue) between the volar and the dorsal test sites increase with age.

Conclusions: Biomechanical parameters allow the evaluation of intrinsic aging in the concept of overall photoaging resulting from the combination of environmental damages superimposed to the intrinsic changes.
Clinical testing of new drugs for lesional skin diseases such as psoriasis A new delivery system
Authors: Farber Eugene M. , Wilkinson David I. , Trozak Daniel J.
Published: October 2006

Background/aims: Efficacy evaluation of new antipsoriatic drugs is difficult in the absence of good animal models. In the experimental treatment of psoriasis plaques, the administered dose of new drugs has to be kept at a minimum for safety reasons. The object is to introduce an extracorporeal system for experimental drug application based on the Alzet osmotic pump.

Methods: The system consists of four Alzet pumps from which the drug is delivered intradermally to lesional skin via a 21‐gauge needle. Infusion may be continued for up to 2 weeks. Infusion sites are evaluated clinically by the scoring of scaling, erythema and thickness. Evaluation is also based on scoring of the cardinal microscopic features of psoriasis on a 0 to 19 weighted scale.

Results/conclusion: The delivery system was screened using a number of drugs and found useful. The system is cheap and easy to operate.
Echographic assessment of age‐dependent variations of skin thickness
Authors: Lasagni C. , Seidenari S.
Published: October 2006

Background/aims: Skin thickness relative to age is complex and may be influenced both by intrinsic changes, extrinsic changes related to sun exposure and constitution, including sex. Age‐related changes may also differ in different anatomical sites. The object was to characterize skin aging relative to these influences.

Methods: A‐mode and B‐mode high‐frequency (20 MHz) ultrasound examination was performed using the Dermascan C. 162 subjects were examined (91 women, 71 men) in the age range 27 to 90 years. 6 anatomical locations (forehead, cheek, volar forearm, dorsal forearm, upper abdomen, buttocks) were studied.

Results: Females have thinner skin than men. Subjects aged more than 70 years have significant thinning of the skin. Age‐related thinning is more pronounced in women. Relative skin‐thickness decrease is less at sun‐exposed areas in comparison with protected areas.

Conclusion: Ultrasund examination allows characterization of skin aging, and the influences of sex and anatomical site with sun‐induced changes were differently superimposed on intrinsic changes and constitution.
Biophysical methods of providing objective documentation of the effects of moisturizing creams
Authors: Lodén Marie
Published: October 2006

Background/aims: Moisturizers are widely used to relieve the clinical and subjective impressions of dry skin, such as roughness, scaling, and an uncomfortable feeling of tightness. Several noninvasive methods are available for objectively evaluating the physical properties of the stratum corneum and the quality of its surface. Increasing demands for scientific documentation of advertising claims have led to the use of these methods for studying skin response to moisturizers. This review provides some insight into how performance of moisturizers can be measured.

Methods: Biophysical methods for examination of skin properties, such as surface contour, scaling, surface lipids, friction, transepi‐dermal water loss, hydration and elasticity are briefly described.

Conclusions: Application of moisturizers to the skin induces measurable tactile, visual and functional skin changes, which can be measured with noninvasive instruments. The use of such instruments allows objective examination and follow‐up of therapeutic effects without interfering with the studied skin area.
Mechanism of action of a lipophilic derivative of salicylic acid on normal skin
Authors: Lévêque J. L. , Corcuff P. , Gonnord G. , Montastier C. , Renault B. , Bazin R. , Piérard G. , Poelman M. C.
Published: October 2006

Background/aims: Keratolytics are agents used for a very long period of time to improve various skin disorders such as acne, hyperkeratoses, ichtyose etc. Very little is known about their mechanism of action on healthy skin. On man, the chronic application of a cosmetic cream containing a lipophilic derivative of Salicyclic acid (LSA) markedly improves the aspect and texture of the skin. Different methods were used to investigate the mechanisms of action of this new compound, compared to salicyclic acid.

Methods: Both non‐invasive and histologic methods were used on the dorsal forearm of human volunteers treated with the products. Concerning the non‐invasive methods, TEWL, silflo replica and confocal microscopy were used. On shave biopsies, various histometric parameters were measured by image analysis after different staining. The use of antibody MIB‐1 reacting with the proliferating nuclear antigen Ki 67 allows one to measure the epidermis proliferation index.

Results: Compared to the excipient alone, presence of LSA 1% improves smoothness and firmness of the skin. The appearance in terms of clearness and healthy complexion is also improved. The thickening of all the living epidermis layers is obtained by both histometric measurement and confocal microscopy. This acanthosis is only recorded on the LSA‐treated zones. The Ki 67 labelling study shows that LSA significantly increases the skin proliferation index.

Conclusions: Salicylic acid, and more markedly its lipophilic derivative (LSA), appear to have a significative effect on the renewal of the living epidermis. This probably explains the cosmetic improvement of the skin obtained after a 1‐month treatment with a cream containing this new molecule.
Corneometiy measurements to evaluate skin dryness in the modified soap chamber test*
Authors: Paye M. , Van de Gaer D. , Morrison B. M.
Published: October 2006

Background/aims: Patch test procedures have been developed to compare the irritation potential of surfactant‐based products. Skin changes due to product application are usually assessed visually by a trained evaluator using standard scoring scales or instrumentally. This study has been carried out to optimize the assessment of skin dryness in the Modified Soap Chamber Test both by visual scoring and Comeometer measurement, with transepidermal water loss as an additional measure.

Methods: Products were applied, under occlusion, to the skin, for 2 successive periods of 24 and 21 h; skin reactions were evaluated 3 h after removal of each series of patches, and followed up to 7 days after patches had been removed.

Results: Skin dryness progressively develops after patch removal, and reaches a maximum 3 to 5 days later. Capacitance measurements correlate the best with visual scoring of dryness when waiting 5 days after patch removal before assessment.

Conclusions: Comeometer is an useful instrument to quantify observed dryness only when transepidermal water loss has recovered a value close to its baseline value. For both visual and instrumental assessments of skin dryness, waiting 3 to 5 days after patch removal in the Modified Soap Chamber Test will provide the most valuable results.
Measurement of shrinkage ability of the stratum corneum under dehydration conditions*
Authors: Hatzis John
Published: October 2006

Background/aims: Pliability and elasticity of stratum corneum (SC) depends on hydration. The aim of the present study was to introduce a new method for the measurement of the ability of the stratum corneum to shrink following dehydration and rehydration.

Methods: The experimental bulla roof of 6 normal volunteers, 3 men and 3 women (40‐60 years old) and 2 patients suffering from x‐linked ichthyosis were examined. The experimental bulla was made on the flexure surface of the left forearm after exposure to NH4OH vapors for 15 min. The measurements were performed by the Cutech In Vivo Extensometer (Stiefel). The instrument arms were retained constant and each force applied upon them was able to recorded by graph, and that force was measured quantitatively. The bulla roof was stuck on the instrument arms, in situ.

Results: In the laboratory environment, the adherent SC on the instrument arms was dehydrated and as a result, a shrinkage force appeared which reached a maximum (mean value=21.6 g; force per 0.6 cm2 of SC) at 18‐25 minutes. Artificial SC hydration (2 drops of water for 10 s, separately on each SC surface) showed as a result immediate disappearance of the shrinkage force which was followed by a gradual reappearance of the shrinkage force level at 8‐16 min. This phenomenon had a high reproducibility. Similar phenomena were observed in the SC of the x‐linked ichthyosis patients.

Conclusions: We considered that the shrinkage ability of the SC can be used as a marker to study SC hydration; it is also responsible for some clinical problems (chapping during winter, cracking in asteatosis, etc.) and plays an important role in desquamation of a single corneocyte or scale. Our experimental model can be used to evaluate substances or emolients’action on SC hydration.
Image analysis in dermatopathology
Authors: Fleming Matthew G.
Published: October 2006

Background/aims: Image analysis in dermatopathology has been used for DNA ploidy analysis, morphometry, stereology, and quantitative immunohistochemistry. The object is to review image analysis in dermatopathology and evaluate these modalities and their application in pigmented lesion pathology, for elucidation of tumor behaviour and architecture and as an aid in tumor identification and prognostication.

Conclusion: Image analysis in dermapathology has a huge potential. The techniques are difficult and at present mainly used in specialized centres.
Quantitative surface topography as a tool in the differential diagnosis between melanoma and naevus
Authors: Connemann Bernhard J. , Busche Heidrun , Kreusch Jürgen , Teichert Hanns‐Martin , Wolff Helmut H.
Published: October 2006

Background/aims: The mainstays of the clinical diagnosis of melanoma are asymmetry, border irregularity, color variegation, and a diameter >6 mm, and any major progress in diagnostic accuracy will probably be related to the development of additional criteria. Such independent criteria might arise from the study of the geometry of the tumour surface, because this quality has been substantially disregarded until now. Our work is aimed at utilizing the surface topography for the differential diagnosis between malignant melanoma and naevocytic naevus.

Methods: Dynamically focusing optical profilometry was used to measure the surfaces of negative replicas of melanocytic skin tumours and of the surrounding normal skin. 21 silicone imprints of superficial spreading melanomas and 25 imprints of naevocytic naevi were examined.

Results: Melanomas and naevi differed with respect to a variety of statistical surface parameters, and a linear discriminant analysis correctly allocated 19 out of 21 melanomas (90%) and 21 out of 25 naevi (84%). To get an unbiased estimate of the errors to be expected with this classification rule, we calculated bootstrap‐corrections to the apparent errors. Estimated probabilities of correct allocation were 84.1% for melanomas and 77.1% for naevi.

Conclusion: Our findings suggest that simple statistical parameters of surface topography can differentiate effectively between malignant melanomas and naevocytic naevi.
Efficient segmentation of large‐area skin images: an overview of image processing*
Authors: Filiberti Daniel P. , Bellutta Paolo , Ngan Phillip , Perednia Douglas A.
Published: October 2006

Background/aims: This paper is the first of a series describing research and development performed by the SPOTS project towards automating the process of monitoring pigmented lesions for change over time. A comprehensive overview of digital image processing techniques used for the systematic approach to segmentation of large‐area skin images, including the description and classification of skin features, is presented.

Methods: The multiresolution hierarchical segmentation technique, which makes use of image pyramid data structures and cooperative computation with unforced linking, was used to group pixels with similar color properties. This technique was further enhanced to enforce contiguity of segments by determining connected components. The resulting segmentation was then classified by using representative properties of pyramid nodes as input to a cascade of multilayer perceptron neural networks trained using the classical backpropagation algorithm. In order to make our system more resistant to imaging distortions, a technique was developed to grow regions based upon the resulting classification.

Conclusions: This system produces a segmentation at multiple resolutions based upon color, where each segment is a contiguous group of pixels on the image. The classification makes use of both spatial and color properties, as well as parent‐child relationships within the pyramid. The addition of classification‐driven region growing reduces the change in lesion area where the boundary fades into surrounding skin. Furthermore, the system contains parameters that can be tuned to provide desirable results.
EEMCO guidance for the assessment of dry skin (xerosis) and ichthyosis: evaluation by stratum corneum shippings
Authors: Piérard Gérald E.
Published: October 2006

Background/aims: Evaluation of scaliness in xerotic and ichthyotic conditions is conveniently addressed by stratum corneum stoppings.

Material/methods: A guidance for the use of sticky slides, casual adhesive tapes, specially designed adhesive‐coated discs and cyanoacrylate skin surface strippings is presented. The samples may be rated by visual inspection, weighting, optical measurements without or after specific staining, and morphometry.

Conclusion: The assessment of scaling conditions by stratum corneum stripping methods may be validly used in the laboratory. Interpretations, however, must be cautious. Direct extrapolations with respect to the water content in the stratum corneum should be avoided.
Quantification of cutaneous pharmacological reactions: comparison of laser Doppler scanning, colorimetry, planimetry and skin temperature measurement
Authors: Stücker Markus , Reuther Tilmann , Hoffmann Klaus , Aicher Bernhard , Altmeyer Peter
Published: October 2006

Background/aims: 2‐dimensional laser Doppler scanning distinguishes itself particularly by its good reproducibility with regard to both time and site. The aim of this study was to investigate this relatively new procedure in localised hyperaemic reactions and to compare it to already established techniques.

Methods: We used a pharmacological test system with the rubefacient substances nonivamide, nicoboxil, a combination of these 2 substances as well as the inactive ointment base. Prior to and for up to 8 h after application of the test substances, measurements were made of the flow by means of laser Doppler scanning, the skin temperature by means of a probe thermometer, the colour of the skin by means of tristimulus‐color‐imetry and the area of erythema by means of planimetry.

Results: With the parameters “maximum hyperaemic area” (laser Doppler scanning), planimetry and the a*‐value of the lab.*‐system (colorimetry), a significant difference was demonstrated between the combination of the active substances and the individual substances (p<0.0002; p<0.002; p<0.0469). The “maximum hyperaemic area” with laser Doppler scanning correlated significantly (p<0.0001) with the planimetrically determined area. The correlation coefficient was high (0.88≤r≤s0.92). The correlation between the “maximum hyperaemic area” and the * a‐value was also significant (p<0.0001), but the correlation coefficient was smaller (0.64≪r≪.82).

Conclusions: In summary, in our test system, laser Doppler scanning, colorimetry and planimetry had the same ability to quantify cutaneous pharmacological reactions. Laser Doppler scanning, however, has the advantage that it can be used without any contact whatsoever with the skin.
Differentiation of inflicted dermal burns by high‐frequency ultrasound scanning
Authors: Stender Ida‐Marie , Nakagawa Hidemi , Shimozuma Michiro , Søndergard Jørgen
Published: October 2006

Background/aims: The depth of experimentally inflicted superficial/partial dermal burns and deep dermal burns were non‐invasively evaluated using a 30 MHz B‐mode high‐frequency ultrasound scanner.

Material/methods: Superficial and deep burns were produced in 10 Harley female albino guinea pigs. Ultrasound scanning was performed immediately after, and 24, 48, 72 and 96 postbum. Specimens for histology were obtained after 72 h.

Results: The echo reflection at the dermis‐subcutaneous interface was easily defined 2 days after burn infliction in all superficial/partial dermal burns, whereas it was disturbed and not detected in any deep dermal burn.

Conclusions: It is concluded from our study that the ultrasonography of the deep dermis, especially the dermis‐subcutaneous interface, is of major importance in the diagnostic and prognostic evaluations of burns.
Permeability of protective gloves to sodium lauryl sulfate. Release chambers used as an in vitro test system
Authors: Ramsing Dorte W. , Fullerton Ann
Published: October 2006

Background/aims: Gloves are important and necessary in many occupations especially in wet work. They may offer a protection against harmful materials, but many substances may also penetrate protective gloves.

Methods: The permeability of 6 different commonly used protective gloves to the anionic detergent sodium lauryl sulfate (SLS) was investigated. The gloves were tested as membranes in diffusion cells at 32°C. (35S)SLS 1% was used as permeant and synthetic sweat was used as recipient. Samples were counted on a scintillation counter.

Results: During a test period of 24 h, none of the gloves tested were found to be permeable to SLS.

Conclusions: The gloves tested were found to offer protection against SLS. The difussion cells were useful for in vitro testing of protective gloves under controlled experimental conditions.
Non‐invasive cosmetic efficacy testing in human volunteers: some general principles*
Authors: Salter David
Published: October 2006

Background/aims: The Sixth Amendment to the European Union's Cosmetics Directive 76/768/EEC requires “proof of the effect claimed for the cosmetic product, where justified by the nature of the effect or product”. To avoid unnecessary claim support disputes, it may be helpful for there to be discussion in the literature to clarify what is generally considered to be sufficient proof of efficacy. Certainly most will wish to encourage efficacy study methodologies which simultaneously (a) ensure an adequate level of quality based on accepted principles of good scientific investigation; (b) are broad and flexible so that detailed procedure can be adapted to suit local needs and conditions; (c) are relevant to the needs of producers, regulatory authorities and consumers.

Conclusion: To progress these aims, it appears that the same basic set of considerations arises in all contexts. This is outlined under a series of key headings in the present paper, which may serve as a basis for further discussion.
In vivo skin relief measurement using a new optical profilometer
Authors: Potorac A. D. , Toma I. , Mignot J.
Published: October 2006

Background/aims: Usually, skin topography is quantified by means of 2D profilometry using negative‐ or positive‐replicas. To allow a direct in vivo measurement, a new profilometer is built, based on an optical triangulation principle.

Conclusion: High speed of measurement can be reached using a non contact profilometer. The ability of a position sensing detector to read the center of gravity of the spot reflected by the skin surface, allows one to reduce the effects of the enlargement due to the skin absorption of the laser beam.
Effects of site and menstrual cycle on barrier function and stratum corneum water‐holding capacity
Authors: Berardesca Enzo , Distante Fernanda , Vignoli Gian Piero , Rabbiosi Giacomo
Published: October 2006

Background/aims: Areas of the skin with similar anatomical structure may have different functional behaviour. In vivo barrier function and stratum corneum water‐holding capacity during the menstrual cycle on two sites of the volar forearm (upper and lower) and on the anterior aspect of the thigh were evaluated using the plastic occlusion stress test (POST).

Methods: 13 healthy women (age 31 ± 4) with regular menses entered the study. POST was performed by applying a plastic chamber (1.8 cm diameter) on the skin for 24 h. After removal the skin surface water loss (SSWL) was measured using an evaporimeter (EP1‐Servomed, Sweden) every 5 min for 30 min. Measurements were taken on the 10th and 25th day of the menstrual cycle. Statistical analysis was performed using one‐factor Anova for repeated measures. Free and bound water compartments of evaporation were also analysed.

Results: Higher hydration and SSWL were detectable on the 25th day of the cycle. However, no significant influence of menstrual cycle was found. Significant differences between the upper and lower volar foream were detected (P < 0.001).

Conclusion: The differences observed were mainly related to the evaporation of bound water, confirming a different barrier function at the sites investigated; therefore, it must be taken into account that adjacent skin sites with equal structure may have different functional behaviour.
CaF2:Dy and CaF2 crystal‐based UV dosimeters
Authors: Wulf Hans Christian , Gniadecka Monika
Published: October 2006

Background/aims: Monitoring of ultraviolet (UV) exposure in humans is important, since UV has been implicated in the pathogenesis of skin cancer, skin ageing and immunosuppression. Biological and physical dosimeters are being developed to measure occupational and environmental UV radiation exposure. We studied the UV‐dependent thermoluminescence in CaF2:Dy and CaF2 crystals and report on the development of a small personal UV dosimeter based on the thermoluminescent phenomenon.

Methods: CaF2:Dy or CaF2 was sensitized to UV by heating for 1‐3 h to 750‐950oC on different supports (porcelain, steel, preheated steel, silicon, chromium, manganese, iron, cobalt, nickel, copper, Fe2O3, Fe3O4). Sensitized crystals were irradiated with UV of different energies and wavelengths. Thermoluminescence of irradiated crystals was measured at different temperatures.

Results: Maximal sensitivity of the crystals to UV was obtained after preheating to 900oC on steel and manganese supports. Sensitivity could be improved further by prolonging heating time. CaF2:Dy and CaF2 were most sensitive to short‐wave UVC and UVB radiation. Based on these findings we have constructed personal UVB and UVC dosimeters.

Conclusion: Development of personal UVC and UVB dosimeters based on UV‐induced thermoluminescence in CaF2:Dy and CaF2 crystals is feasible. CaF2:Dy and CaF2 crystals are not sensitive enough to long‐wave UV radiation to be used for construction of UVA dosimeters.
In vivo evaluation of sunscreens by spectroscopic methods
Authors: Utz Sergei R. , Knuschke Peter , Sinichkin Yuri P.
Published: October 2006

Background/aims: The methods available for testing the efficacy of topical sunscreens have improved considerably in recent years. Nevertheless, so far no simple and rapid test has been proposed to measure in vivo transmission spectra of sunscreens in the UVA region.

Methods: Spectral changes that occur after sunscreen application were measured with a fluorescence spectrometer (LS 50B, Perkin Elmer, UK) equipped with a Y‐shape quartz guide for in vivo measurements. Three sunscreens with different protection factors in the UVA range were tested. The excitation‐emission maps of human collagen, skin and sunscreens were analysed.

Results: As a consequence of the human skin and sunscreen fluorescence map analysis, the optimal spectral regions (both for direct and indirect fluorescence measurements) were detected. In vivo fluorescence and remittance spectroscopy were used to investigate the time dependence in transmission spectra of epidermis with applied sunscreens. We also evaluated the feasibility of in vivo fluorescence measurements for the investigation of the sunscreens’water‐resistance.

Conclusion: The procedure is simple, and values obtained can be used to predict UVA protection on the basis of the mathematical algorithms.
Analysis of laser Doppler perfusion images of experimental irritant skin reactions
Authors: Wårdell Karin , Andersson Thomas , Anderson Chris
Published: October 2006

Background/aims: Laser Doppler perfusion imaging (LDPI) permits measurement of skin blood flow changes in patch test reactions. It is, as yet, unclear how collected data can best be handled and presented in order to maximize the possible discriminatory advantage of the imaging technique and to make the selection of data for statistical analysis as objective as possible. The aim of the present study was to compare a new software program (LDISOFT) for the analysis of LDPI images with the built‐in standard statistical functions in the LDPI system (PIM 1.0). In addition, a modification of the software was used to gather additional data by performing sequential perfusion images.

Methods: A dithranol cream was applied under Finn chambers for 30, 60 and 90 min on the ventral forearm skin of three volunteers. Photographic documentation and LDPI recordings were performed immediately after the removal of the Finn chambers and at 24, 48, 72 and 96 h. By the use of the above mentioned software, rectangular and threshold selected regions of interest were used to find an optimal way of calculating the mean perfusion and extent of the reactions.

Results: An LDISOFT threshold of 2 V was adequate and showed agreement (r<0.902, n=78) between mean perfusion analysis performed by LDISOFT (threshold‐steered region of interest) and LDPI statistics (rectangular region of interest). The LDISOFT program had the added advantage of comparing application‐site size with reaction size. Sequential recordings showed both spatial and temporal perfusion variability.

Conclusions: Utilization of the full potential of LDPI will involve optimization of data analysis and presentation. A more “automated” system for data analysis will reduce bias due to subjective selection of analysis area. Particularly in weaker reactions, in irregular shaped or ring reactions and when there is non‐specific background irritation, this may represent an advantage. Averaging of sequential recordings reduced background noise.
Measurement of skin mechanics
Authors: Jemec Gregor B. E. , Gniadecka Monika , Jemec Barbara
Published: October 2006

Background/aims: Skin mechanics may be affected by a number of dermatological and systemic conditions, and reliable quantification of skin distension may therefore be of considerable interest. This study was undertaken in order to assess the intra‐and inter‐individual variation of measurements of skin distensibil‐ity when using Dermaflex A.

Methods: Dermaflex is a suction device that measures the deformation of the skin surface within a 10‐ mm cup following application of given suction. Three levels of suction were studied on the flexural side of the forearm in 19 healthy volunteers.

Results: Increasing levels of suction produced significantly increasing skin distension (P<0.0001) with a significant non‐linear trend (P=0.0310). Inter‐individual variation (coefficient of variation range 15.43‐27.88%) was significantly larger than intra‐individual variation (coefficient of variation range 9.16‐11.45%, P=0.0031) throughout the range of suction tested. There was no significant difference between the intra‐ and inter‐individual coefficients of variation with different levels of suction.

Conclusion: The results suggest that measurements of skin distensibility can be a useful method for objective determination of skin mechanics.
Diagnosis of Raynaud's phenomenon by thermography
Authors: Ammer Kurt
Published: October 2006

Background/aims: The aim was to clarify whether cold fingers before a moderate cold stress test can predict a prolonged delay (more than 20 min) in rewarming, as diagnostic for Raynaud's phenomenon.

Methods: A retrospective study was conducted on 71 patients suspected of suffering from Raynaud's phenomenon. The thermal gradient from the metacarpophalangeal joints to the finger tips was calculated for each finger and cold fingers were defined by a temperature difference of more than −0.5°2C.

Results: Combining the frequencies of cold fingers with a diagnosis Raynaud's phenomenon resulted in a sensitivity of 78.4%, a specificity of 72.4% and diagnostic accuracy of 74.0%.

Conclusion: Based on a positive predictive value of 58.5%, it was concluded, that a prolonged delay of rewarming after a cold stress test cannot be predicted sufficiently by the presence of cold fingers alone, and that a cold stress test is necessary to confirm the diagnosis objectively.
Can early malignant melanoma be differentiated from atypical melanocytic nevi by in vivo techniques?
Authors: Rao B. K. , Marghoob A. A. , Stolz W. , Kopf A. W. , Slade J. , Wasti Q. , Schoenbach S. P. , De‐David M. , Bart R. S.
Published: October 2006

Background/aims:

Atypical melanocytic nevi (AMN) share some or all of the clinical features of malignant melanoma (MM). The clinical sensitivity for diagnosing MM by physicians experienced in evaluating pigmented lesions is reported to range from 73% to 89%. This study attempted to determine whether clinical sensitivity can be increased by dermoscopy (epilumnescence microscopy, dermatoscopy).

Methods:

A total of 72 melanocytic neoplasms were histologically diagnosed as either AMN or early MM (<1 mm Breslow thickness). Prior to excisional biopsy, each lesion was photographed without oil being applied to its surface (clinical photo); subsequently it was photographed with oil applied (dermoscopic photo). Each 35 mm color transparency, visualized on a rear‐view projector, was analyzed by two experienced and two less experienced observers. Each of them recorded one clinical, one “overall” dermoscopic, and one “scored” dermoscopic diagnosis: either AMN or MM for each.

Results:

Histologically, 21 lesions were diagnosed as MM and 51 as AMN. The observers, except one of the less experienced, had an increase in sensitivity ranging from 5 to 15% for diagnosing MM with dermoscopy. The increase was higher for the scored dermoscopy than for overall dermoscopy. Diagnostic Accuracy (DA) changed from −20% to +11%. Specificity (SP) changed from −23% to +24% with scored dermoscopy. Three of the 21 MMs were missed by one or more observers using all three in vivo diagnostic methods.

Conclusions:

In this study dermoscopy, when used by experienced dermatologists, increased diagnostic sensitivity and index of suspicion but decreased specificity and diagnostic accuracy for diagnosing MM. Therefore, dermoscopy may result in an increased number of biopsies of benign lesions (AMN), but would decrease the probability of missing MM.
Can early malignant melanoma be differentiated from atypical melanocytic nevus by in vivo techniques?
Authors: Gutkowicz‐Krusin D. , Elbaum M. , Szwaykowski P. , Kopf A. W.
Published: October 2006

Background/aims: Differentiation between early (Breslow thickness less than 1 mm) malignant melanoma (MM) and atypical melanocytic nevus (AMN) remains a challenge even to trained clinicians. The purpose of this study is to determine the feasibility of reliable discrimination between early MM and AMN with noninvasive, objective, automatic machine vision techniques.

Methods: A data base of 104 digitized dermoscopic color transparencies of melanocytic lesions was used to develop and test our computer‐based algorithms for classification of such lesions as malignant (MM) or benign (AMN). Histopathologic diagnoses (30 MM and 74 AMN) were used as the “gold standard” for training and testing the algorithms.

Results: A fully automatic, objective technique for differentiating between early MM and AMN from their dermoscopic digital images was developed. The multiparameter linear classifier was trained to provide 100% sensitivity for MM. In the blind test, this technique did not miss a single MM and its specificity was comparable to that of skilled dermatologists.

Conclusions: Reliable differentiation between early MM and AMN with high sensitivity is possible using machine vision techniques to analyze digitized dermoscopic lesion images.
Diagnosis of cutaneous melanoma: accuracy of a computerized image analysis system (Skin View)
Authors: Cristofolini M. , Bauer P. , Boi S. , Cristofolini P. , Micciolo R. , Sicher M. C.
Published: October 2006

Background/aims: Early diagnosis is essential for reducing the high mortality of CM (cutaneous melanoma). An expert dermatologist has a diagnostic accuracy of 85% but, in performing mass screening, the problem is to transfer the experience of a specialized centre to peripheral health clinics. Therefore, some computerized analysis systems were made. The aim of this paper is to compare the diagnostic accuracy of one such system, the Skin View System (SVS), to the accuracy of a well trained dermatologist in order to establish the real usefulness of the instrument and to verify how much it can help the diagnostic accuracy of the clinician in a dermatology setting.

Method: During a campaign for the early diagnosis of CM, 176 patients with small and flat pigmentary lesions underwent clinical diagnosis, computerized analysis with SVS and skin biopsy. For clinical and computerized diagnosis, we evaluated sensitivity, specificity, true and negative predictive value.

Results: The statistical evaluation, in our study, reveals that the computerized system has a diagnostic accuracy lower than that of a trained dermatologist.

Conclusions: This computerized system does not help the clinician in the diagnosis of pigmented lesions.
Efficient segmentation of large‐area skin images: a statistical evaluation
Authors: Filiberti D. P. , Gaines J. A. , Bellutta P. , Ngan P. , Perednia D. A.
Published: October 2006

Background/aims: This paper is the second of a series describing research and development performed by the SPOTS project towards automating the process of monitoring pigmented lesions for change over time. Several parameters of the system are introduced along with the methods used for determining appropriate settings. We then describe our experimental setup and present a detailed statistical analysis to evaluate system performance.

Methods: There exist three sets of parameters in our system related to image segmentation, classification, and a region‐growing step that can be individually tuned. The multiresolution hierarchical segmentation algorithm contains both a set of weights for the tristimulus color values used in calculating color differences and a contrast threshold used to identify root nodes that represent image segments. These were tuned using a synthetic image to simulate a pigmented lesion with irregular border and by estimating the parameters by successive approximations. The neural network classification used to detect lesion segments was trained using a 10‐fold cross‐validation, and the output classification threshold was set to yield a small false negatives ratio. Finally, there is a growing threshold used to determine whether neighbor regions should be merged in the region‐growing step that was selected to minimize the change in area for different translations of a synthetic lesion. In order to evaluate the performance of the system, we compared the identified lesions with manually localized lesions. Ten images of the same area were taken from two subjects presenting lesions of varying size and different background skin texture. A sample of two images from the set was used to simulate variations in acquisition. Five operators were asked to trace lesion boundaries in two passes, separated by a few days, to evaluate the consistency of operators among themselves. The system was then run on the images using the optimal set of parameters. The results were analyzed for independent observation, matched pass, and doubly‐matched pass data.

Conclusions: Independent observation data indicates that the system finds significantly more objects than any of the human operators, but the areas reported are not significantly different on average. Matched pass data show that the correlations of the system with human operators is quite high. The system agrees with humans only slightly less than they do among themselves and has a tendency to report slightly smaller areas. The correlation between system and human peformance was further reinforced by the doubly‐matched arrangement. These results indicate that our system is as reliable and consistent as our human reference, yielding similar performance.