bluuebunny/crossref_metadata_2025 huggingface dataset:
International Capital Mobility and Development Policy in a Dual Economy
Authors: Din Musleh‐ud
Published: October 2006

This paper introduces international capital mobility in a general‐equilibrium model of a small developing economy which is characterized by a dualistic economic structure. The model is then used to analyze the positive and the normative aspects of development policies that are often recommended for achieving employment‐related objectives in developing economies.
Transfer Pricing and Strategic Taxation of Globally Joint Inputs
Authors: Konan Denise Eby
Published: October 2006

This paper models strategic taxation policy of home and host governments when a multinational enterprise sets transfer prices on globally joint inputs such as research and development. Tax credit and deduction allowances, as well as no taxation of foreign‐earned profits, result in identical optimal transfer‐price solutions and national income effects in both countries. An equilibrium home‐tax solution is to tax foreign‐earned profits at a higher rate than domestically earned profits. The multiantional responds by shifting profits abroad through transfer‐pricing mechanisms.
Falling Behind and Catching Up in a Model of North‐South Trade
Authors: Durkin John T.
Published: October 2006

This paper analyzes a formal, dynamic model of the center‐periphery problem. The model features falling relative demand for agricultural goods, a higher rate of technical change in manufacturing, and a quality‐differentiated manufactured good. Income differences imply a potential for intra‐industry trade, while technical change generates product cycle type results. The main insight is that a closing of the North‐South technology gap does not necessarily imply catching up, because of the falling relative demand for agricultural goods. The South catches up only if it exports lower‐quality varieties of the manufactured good and closes the technology gap.
Purchasing Power Parity When Prices Are I(2)
Authors: Crowder William J.
Published: October 2006

This paper examines the purchasing power parity (PPP) hypothesis over the modern float using data on 15 OECD currencies. Evidence is presented that suggests the price levels evolve as second‐difference stationary processes, i.e., integrated of order two (P1– I(2)). A necessary condition for PPP when prices are I(2) is that prices are cointegrated across countries to an I(1) relative price. In general this relative price is not the same as the simple price ratio. For some of the relationships examined, this relative price level is cointegrated with the exchange rate, implying a long‐run equilibrium between nominal exchange rates and prices.
Which Single Currency for Western Europe?
Authors: Kutan Ali M. , Melvin Michael
Published: October 2006

The Maastricht Treaty calls for a single European money in the third and final stage of European monetary integration. The purpose of this paper is to infer the preferred currency from the point of view of economic agents in each EMS country by ranking the realized distributions of returns from holding foreign currencies. These rankings are obtained using the notion of generalized stochastic dominance. The preferred currency varies with time and the portfolio considered. In all cases, the ECU is not supported as a likely dominant money.
Tariff Reductions in the Presence of Foreign Direct Investment
Authors: Olarreaga Marcelo
Published: October 2006

This paper argues that the welfare effects of trade liberalization in the presence of foreign direct investment obtained under perfect competition cannot be extended to imperfectly competitive markets. In the Heckscher‐Ohlin model, trade liberalization may be paradoxically immiserizing when the traditional welfare‐increasing result is corrected for the change in foreign capital revenue. Under imperfect competition this cannot occur, except under rather implausible assumptions. Indeed, a tariff reduction is expected to increase welfare when the welfare indicator is corrected for the presence of foreign capital, regardless of the type of market structure and the form of competitive rivalry.
Revenue Motives and Trade Liberalization
Authors: Feldman David H. , Gang Ira N.
Published: October 2006

Governments in more‐developed economies partially compensate import‐competing industries when world prices fall, i.e., they lean against the wind. Less‐developed economies often liberalize in response to the same shock. We use a political‐support maximization model with revenue motives to derive conditions under which a rational policymaker would respond to lower woild prices by reducing tariff protection for an import‐competing industry. An initial tariff that exceeds the maximum revenue level proves necessary but not sufficient for politically optimal liberalization following a fall in the world price of the importable good.
Cross‐Hedging of Exchange‐Rate Risk
Authors: Broll Udo , Eckwert Bernhard
Published: October 2006

For currencies with highly developed forward markets a well‐known separation theorem holds which implies that international firms fully hedge the exchange rate risk if the forward markets are unbiased. In this paper we present a model of a risk‐averse firm when perfect hedging instruments are not available. Instead the firm can cross‐hedge the exchange‐rate risk by using the forward markets of a third country's currency. We demonstrate that the unbiasedness of all forward markets does not imply full hedge, although the firm has the option to hedge all the risks.
Correcting Trade Distortions in a Small Open Economy
Authors: Lahiri Sajal , Raimondos Pascalis
Published: October 2006

This paper considers the second‐best strategy of correcting a wide variety of trade distortions in a small open economy with perfect competition in all markets. Using the tools of duality, we obtain some general properties of the structure and the levels of the optimal taxlsubsidy rates. The paper also analyzes the welfare effects of unilateral piecemeal trade policy reforms when some of the quota distortions—imposed by the foreign countries—are unalterable. It is shown that the merits of unilateral trade policy reforms that are emphasized in the literature crucially depend on the absence of unalterable foreign imposed quotas.
Endogenous Growth in a Dependent Economy with Traded and Nontraded Capital
Authors: Turnovsky Stephen J.
Published: October 2006

The equilibrium growth path for this economy depends upon the relative sectoral capital intensities of the two production functions. If the nontruded sector is relatively intensive in traded capital, both the relative price of nontraded output and the price of installed capital always remain at their respective steady‐state levels. Traded capital and aggregate wealth are always on their respective steady‐state growth paths. Nontraded capital undergoes transitional dynamics, ultimately converging to the growth rate of traded capital and an equilibrium ratio of traded to nontraded capital. If the sectoral intensities are reversed, both asset prices will follow transitional adjustment paths.
International R&D Rivalry and Industrial Strategy without Government Commitment
Authors: Leahy Dermot , Neary J. Peter
Published: October 2006

We examine optimal industrial and trade policies in a series of dynamic oligopoly games in which a home and a foreign firm compete in R&D and output. Alternative assumptions about the timing of moves and the ability of agents to commit intertemporally are considered. We show that the home export subsidy, R&D subsidy and welfarc are higher when government commitment is credible than in the dynamically consistent equilibrium without commitment. Commitment thus yields welfare gains (though they are small) but so does unanticipated reneging, whereas reneging which is anticipated by firms yields the lowest welfare of all.
Exchange Rate Changes and Pricing Behavior of US Exporters
Authors: Yang Jiawen
Published: October 2006

This paper studies export pricing behavior following exchange rate changes in US manufacturing industries. Through a monopolistic model, the paper predicts that export prices should change, but less than proportionally, in response to exchange rate changes if either or both demand elasticity and marginal cost are variable. Cross‐industry variation of such price changes can be explained by the difference in demand elasticities between the domestic and the export markets, the elasticity of marginal cost with respect to output. and the export share. These predictions are supported by the empirical findings of the paper.
Time‐Series Support for Balassa's Productivity‐Bias Hypothesis: Evidence from Korea
Authors: Bahmani‐Oskooee Mohsen , Rhee Hyun‐Jae
Published: October 2006

In this paper we use the Johansen and Juselius cointegration technique and quarterly data over the period 1979–1993 to test the productivity‐bias hypothesis between Korea and four of its major trading partners (Germany, Japan, the United Kingdom, and the United States). The results show that in all four cases the deviation of purchasing‐power parity (PPP) from the equilibrium exchange rate has a long‐run relationship with the productivity ratios, supporting the notion that as Korea becomes relatively more productive, the Korean won appreciates in real terms.
Akira Takayama: A Memoir
Authors: Thompson Henry
Published: October 2006

When Akira Takayama passed away this winter, the economics profession lost one of its most productive and most passionate members. This memoir catalogues Professor Takayama's publications and offers some insight into his contributions and personality from a few of his colleagues.
Measurements of the anaplerotic rate in the human cerebral cortex using 13C magnetic resonance spectroscopy and [1‐13C] and [2‐13C] glucose
Authors: Mason Graeme F. , Petersen Kitt Falk , De Graaf Robin A. , Shulman Gerald I. , Rothman Douglas L.
Published: October 2006

Recent studies in rodent and human cerebral cortex have shown that glutamate‐glutamine neurotransmitter cycling is rapid and the major pathway of neuronal glutamate repletion. The rate of the cycle remains controversial in humans, because glutamine may come either from cycling or from anaplerosis via glial pyruvate carboxylase. Most studies have determined cycling from isotopic labeling of glutamine and glutamate using a [1‐13C]glucose tracer, which provides label through neuronal and glial pyruvate dehydrogenase or via glial pyruvate carboxylase. To measure the anaplerotic contribution, we measured 13C incorporation into glutamate and glutamine in the occipital‐parietal region of awake humans while infusing [2‐13C]glucose, which labels the C2 and C3 positions of glutamine and glutamate exclusively via pyruvate carboxylase. Relative to [1‐13C]glucose, [2‐13C]glucose provided little label to C2 and C3 glutamine and glutamate. Metabolic modeling of the labeling data indicated that pyruvate carboxylase accounts for 6 ± 4% of the rate of glutamine synthesis, or 0.02 μmol/g/min. Comparison with estimates of human brain glutamine efflux suggests that the majority of the pyruvate carboxylase flux is used for replacing glutamate lost due to glial oxidation and therefore can be considered to support neurotransmitter trafficking. These results are consistent with observations made with arterial–venous differences and radiotracer methods.
Leptin: a diverse regulator of neuronal function
Authors: Harvey Jenni
Published: October 2006

It is well documented that leptin is a circulating hormone that plays a key role in regulating food intake and body weight via its actions on specific hypothalamic nuclei. However, leptin receptors are widely expressed in the CNS, in regions not generally associated with energy homeostasis, such as the hippocampus, cortex and cerebellum. Moreover, evidence is accumulating that leptin has widespread actions in the brain. In particular, recent studies have demonstrated that leptin markedly influences the excitability of hippocampal neurons via its ability to activate large conductance Ca2+‐activated K+ (BK) channels, and also to promote long‐term depression of excitatory synaptic transmission. Here, we review the evidence supporting a role for this hormone in regulating hippocampal excitability.
Laser Scanning Photostimulation: New Evidence for Enhanced Recurrent Excitation in a Model of Posttraumatic Epilepsy
Authors: Dudek F. Edward , Staley Kevin J.
Published: October 2006

Enhanced Excitatory Synaptic Connectivity in Layer V Pyramidal Neurons of Chronically Injured Epileptogenic Neocortex in Rats

Jin X, Prince DA, Huguenard JR

J Neurosci 2006;26:4891–4900

Formation of new recurrent excitatory circuits after brain injuries has been hypothesized as a major factor contributing to epileptogenesis. Increases in total axonal length and the density of synaptic boutons are present in layer V pyramidal neurons of chronic partial isolations of rat neocortex, a model of posttraumatic epileptogenesis. To explore the functional consequences of these changes, we used laser-scanning photostimulation combined with whole-cell patch-clamp recording from neurons in layer V of somatosensory cortex to map changes in excitatory synaptic connectivity after injury. Coronal slices were submerged in artificial CSF (23°C) containing 100 μM caged glutamate, APV (2-amino-5-phosphonovaleric acid), and high divalent cation concentration to block polysynaptic responses. Focal uncaging of glutamate, accomplished by switching a pulsed UV laser to give a 200–400 μs light stimulus, evoked single- or multiple-component composite EPSCs. In neurons of the partially isolated cortex, there were significant increases in the fraction of uncaging sites from which EPSCs could be evoked (“hot spots”) and a decrease in the mean amplitude of individual elements in the composite EPSC. When plotted along the cortical depth, the changes in EPSCs took place mainly between 150 and 200 μm above and below the somata, suggesting a specific enhancement of recurrent excitatory connectivity among layer V pyramidal neurons of the undercut neocortex. These changes may shift the balance within cortical circuits toward increased synaptic excitation and contribute to epileptogenesis.
Pulmonary lymphangioleiomyomatosis followed by a localized retroperitoneal lymphangioleiomyoma
Authors: TAI HUI‐CHUN , LIN JUI‐WEI , WANG YI‐HSI , ENG HOCK‐LIEW , LU HUNG‐I , LIU YUEH‐WEI , HUANG CHAO‐CHENG
Published: October 2006

Lymphangioleiomyomatosis is a rare disease that affects females of reproductive age. Microscopically, it is characterized by abnormal proliferation of immature smooth muscle‐like cells that grow diffusely in the lung. Extrapulmonary manifestations in the mediastinum, peritoneum and pelvic lymph nodes are uncommon. We here describe a patient who initially presented with pulmonary lymphangioleiomyomatosis and subsequently developed a localized retroperitoneal mass. Pathologic examination showed that the mass was a lymphangioleiomyoma. The result of the immunohistochemical study was the same as that for the pulmonary lesion. It is therefore suggested that metastatic lymphangioleiomyoma should be included in the differential diagnosis in the patient with pulmonary lymphangioleiomyomatosis presenting with an extrapulmonary lesion.
Immunohistochemical staining of CD10 in atypical fibroxanthomas
Authors: Hultgren Tricia L. , DiMaio Dominick J.
Published: October 2006

Background:  The histologic diagnosis of atypical fibroxanthoma (AFX) may be difficult at times with a differential diagnosis including spindle cell/desmoplastic melanoma and a poorly differentiated squamous cell carcinoma (SCC). While there are immunohistochemical stains that may be used to support a diagnosis of either melanoma or carcinoma, the diagnosis of AFX tends to be one of exclusion.

Methods:  A total of 35 cases including 16 AFXs, 10 poorly differentiated SCCs and nine spindle cell/desmoplastic melanomas were stained with the antibody against CD10.

Results:  There was strong (3+) diffuse expression of CD10 in 15/16 (94%) AFXs, weak (1+) to moderate (2+) patchy expression of CD10 in 5/10 (50%) SCCs and weak (1+) expression of CD10 in 3/9 (33%) spindle cell/desmoplastic melanomas.

Conclusion:  CD10 expression is helpful in distinguishing between AFXs, carcinomas and melanomas and will be useful in a panel of antibodies when distinguishing between these entities.
Nondermatoscopic digital imaging of pigmented lesions
Authors: Stoecker William V. , Moss Randy H. , Ercal Fikret , Umbaugh Scott E.
Published: October 2006

Background/aims: Pigmented lesions are often difficult to evaluate clinically. Improvement of diagnostic accuracy by dermatoscopy has attracted much interet. With advanced digital imaging measurement of assymmetry, border irregularity and relative color as well as texture characteristics, lesional depth and changes in lesional area are now possible, the object of this review is to conclude the present status of these techniques and their potential.

Conclusions: Digital imaging of pigmented lesions to this date include acquiring and storing of images, quantification of clinical features including asymmetry, and teledermatology with transfer of images. Predicted uses include malignancy evaluation, delineation of depth of invasion and the development of large collections of pigment lesions observations. The field is rapidly expanding. As of 1994, it is unknown what role digital imaging will ultimately play in clinical dermatology.
Instrumental evaluation of subclinical responses to 0.05% NiSO4 patch tests
Authors: Nardo A. di , Schiavi M. E. , Seidenari S.
Published: October 2006

Background/aims: The possibility of identifying allergic reactions while they are not clinically evident could prove extremely useful in studying the evolution of skin responses in experimentally‐induced contact dermatitis. In drug research and in cosmetological research, the sensitizing properties of new molecules or haptens present in the product in a low concentration also need be clarified. The object of the present study was to validate noninvasive techniques and their use for the study of subclinical allergic reactions.

Methods: 70 nickel‐sensitized subjects previously standard tested with 5% nickel sulphate in petrolatum were challenged with a 0.05% nickel sulfate solution on the volar aspect of the forearm, application for 24 h and measurement at 72 h. Colorimetry, evaporimetry (transepidermal water loss, TEWL) and high‐frequency echography were used to characterize reactions.

Results: Colorimetry and TEWL did not show any significant differences between patch test areas and control areas. Skin thickness determination, conversely, evidenced a significant increase both with respect to baseline values and control areas.

Conclusion: Echographic evaluation is able to detect modification of skin thickness of subclinical allergic patch test reactions to nickel sulfate while colorimetry and TEWL failed to detected such minute changes.
Erythema‐index of clinical patch test reactions
Authors: Jemec Gregor B. E. , Johansen Jeanne D.
Published: October 2006

Background: Methods for the precise non‐invasive and continuous grading of disease intensity are potentially of great use in a clinical setting. The erythema index offers a good method for assessing UVR induced erythema. Due to the development of a convenient hand‐held spectrometer, it is possible that the method could be used for the grading of eczematous reactions in a clinical setting as well.

Objective: To assess the usefulness of the erythema index for the quantification of eczematous reactions using the Derma‐Spectrometer (Cortex technology, Hadsund, Denmark) in a clinical setting.

Method: The erythema index of 56 patch test reactions ranging from +? to +++, was compared to regional controls and negative patch tests (189). The effects of intrumental application pressure was studied in 5 volunteers. Statistical analysis was carried out using Mann‐Whitney and Jonckheere‐Terpstra tests.

Results: The erythema‐index was significantly higher in all degrees of patch test reactions than in uninvolved regional skin or negative patch tests. It also showed a significant positive trend for higher values in +, ++ and +++ reactions (P<0.0001). In direct comparison, the erythema index was unable to distinguish between?+ and +, or between ++ and +++ reactions. Only the distinction between + and ++ appeared significant (P<0.04). It is suggested that application pressure of the instrument is only of importance in high grades of erythema.

Conclusion: Measurement of erythema index in eczematous reactions appear to be related to the intensity of the reaction, although the method does not reflect the many other changes which occur with increasingly strong reactions (oedema, etc.). The method therefore offers an objective quantitative supplement to clinical grading, especially in weak reactions. It is suggested that the method is better suited for experimental studies with a strict control of confounding factors.
Skin irritancy classification of body cleansing products
Authors: Paye M. , Morrison B. M. , Wilhelm K.‐P.
Published: October 2006

Background/Aims: Mildness of skin cleansing products is often claimed although difficult to substantiate. Both the society and the producer share a common interest that cleansing products are safe in use and that valid methods are used for premarketing evaluation of new products. The object of the present study was to evaluate methodological aspects when three products were compared using two different test systems to characterize their irritant properties.

Methods: A modified soap chamber test (M‐SCT) and an iterative short‐term patch test (IPT) were performed. Eight healthy female volunteers aged 18 to 55 selected as having responsive skin were studied. Colorimetry and measurement of transepider‐mal water loss was employed. A soap, a synthetic detergent bar and a facial cleanser were studied with deionized water as a reference.

Results: The IPT appeared more sensitive than the M‐SCT for the detection and discrimination of irritation. The techniques allowed the ranking of the irritant properties of the products relative to water, which showed low values in both systems.

Conclusion: Ranking of irritant properties of cleansing products was possible even in a limited number of individuals. Iterative short‐term patch test was more sensitive than a modified soap chamber test.
Monitoring wound healing of venous stasis leg ulcers by in vivo 31P magnetic resonance spectroscopy
Authors: Zemtsov Alexander , Dixon Lisa
Published: October 2006

Background/aims: Venous stasis ulcers is a frequent clinical problem. Objective techniques for characterization and monitoring of wound healing are needed including noninvasive study of biochemical changes associated with the healing process. 31P magnetic resonance spectroscopy was not used in the past to study human wound healing in vivo.

Methods: 31P magnetic resonance spectroscopy with study of intracellular pH, phosphocreatine, and the phosphocreatine/inor‐ganic phosphate ratio was used. Six patients with venous leg ulcer and three controls were studied.

Results: Both intracellular pH, phosphocreatine and the phos‐phocreatine/inorganic phosphate ratio were found sensitive indicators of wound healing. Surprisingly the intracellular pH in healing ulcers was in the alkali range.

Conclusion: 31P magnetic resonance spectroscopy was found useful for the study of biochemical changes associated with wound healing. pH in the alkali range was an unexpected observation.
Measurements of limb oedema in chronic venous disease
Authors: Mani R. , Ross J. N. , Keefe M.
Published: October 2006

Background/aims: Limb oedema is of major importance in the development, healing rate and reoccurrence of chronic venous insufficiency and venous leg ulcer. The pathophysiology of limb oedema, and methods of measuring and managing oedema are revisited.

Conclusion: Despite oedeme being a symptom of major importance in venous leg ulcer, our knowledge is still limited. Research and renewed clinical interest in this symptom is predicted in the future.
Non‐invasive methods for determination of oedema and water behaviour in the skin
Authors: Gniadecka Monika
Published: October 2006

Background/Aim: In an accompanying review, Mani and coworkers discuss methods for measurement of global oedema of the limb. Here, we have concentrated on methodology enabling investigation of oedema and water compartment selectively in the skin and its layers. Results of the studies with magnetic resonance and ultrasound based methods are reviewed.

Conclusion: The behaviour of water in normal young and aged skin has been characterised with magnetic resonance and ultrasonography. Little is yet known about water distribution and behaviour in skin oedema characteristic e.g. for the post‐thrombotic syndrome and lymphoedema. Further research in this field is likely to be carried out in the future.
In vivo skin elasticity of 22 anatomical sites
Authors: Malm Mats , Samman Michael , Serup Jorgen
Published: October 2006

Background/aims: Regional anatomical variations in bio‐mechanical properties of skin were not mapped systematically in the past, despite the obvious clinical variation of this function. The object was to describe variations in skin distensibility and elasticity by the use of a suction chamber device.

Methods: 22 different anatomical sites were measured in 25 healthy volunteers aged 5‐72 years. Anatomical sites were numbered systematically from the head toward the foot according to a vertical principle as a part of the study design.

Results: A systematic and vertically oriented decrease of distensibility and hysteresis from the head toward the foot was observed with a gradual increase of skin stiffness toward the ground. Skin elasticity decreased significantly with age. Acral female skin was more easily distended than male skin.

Conclusions: The vertical gradient of skin distensibility was described for the first time. This appears a prerequisite to resist the hydrostatic pressure and influences of gravity. The findings may have important implications in leg ulcer and gravitational syndrome.
Skin biomechanical properties: in vivo evaluation of influence of age and body site by a non‐invasive method
Authors: Couturaud V. , Coutable J. , Khaiat A.
Published: October 2006

Background/aims: Biomechanical properties of the skin are evaluated in vivo by torsion or extension methods. We assessed their modifications as function of age, probe diameter and regional body site.

Methods: For measuring skin extensibility (or traction), we used a non‐invasive suction device on a total of 37 volunteers, consisting of (A) 14 younger women (30.1±7.6 years) and (B) 23 older women (60.2±6.5 years). Measurements were performed on three different areas with 4 different probe diameters. The parameters used were (UE) extensibility; (UV) plasticity; (UR) tonicity; (URUE) elasticity; the difference between the lowest point of the last curve (5th) and that of the 1st is the fatiguability. Concurrently, we measured on each volunteer the microdepressionary network (mDN) length.

Results: Generally, tonicity, extensibility and elasticity decreased; fatiguability increased and plasticity stayed the same; all of these factors apply regardless of age. Results are more homogenous on the volar face of the forearm and with 2, 4 and 6 mm probe diameters. As a general trend, mDN length decreases with age.

Conclusions: The knowledge of this variation is important in interpreting the results obtained after product application. Standardisation of measures with the 2‐mm probe will allow product efficacy determination and the comparison of different products.
High‐frequency ultrasound characterization of normal skin. Skin thickness and echographic density of 22 anatomical sites
Authors: Olsen L. Overgaard , Takiwaki H. , Serup J.
Published: October 2006

Background/aims: Variation in skin thickness relative to anatomical site was little studied in the past. Biopsy cutting and histological processing change tissue geometry. High‐frequency ultrasound allows in vivo measurement of skin thickness of multiple sites. The object was to map regional differences in skin thickness.

Methods: 22 different anatomical sites were studied. The Dermascan C (20 MHz) was used. The acoustic density of the dermis and the epidermal entrance echo was analyzed by the in‐built image analysis software. 18 healthy volunteers aged 24‐41 years were studied.

Results: Extremity skin was thinner than truncal skin, and acoustically dense. Females had thinner and more dense skin in comparison with males. Skin of the palm, sole and the head was thick but weak in density, and the biological variation in the dermis/subcutaneous tissue interphase does not allow highly accurate evaluation in these special sites. There was an overall inverse correlation between skin thickness and acoustic density with thin skin being dense and thick skin being relatively echo‐poor.

Conclusions: Skin thickness and acoustic density reflecting intradermal structure exhibit systematic regional variation with thin and dense skin on extremities in comparison with the trunk and special ultrasound profiles in selected sites such as the face, the palp and sole. Female skin is thinner and more dense in comparison with male skin.
High‐frequency ultrasound measurement of dermis and subcutaneous fat in the newborn infant
Authors: Petersen Jes Reinholdt , Petersen Sten , Serup Jørgen
Published: October 2006

Background/aims: Skin thickness and subcutaneous fat thickness of newborn infants may reflect the condition of the infant including prematurity. Skin thickness and subcutaneous fat thickness might be useful parameters to characterize and monitor the nutritional state of the infant. The objective was to introduce ultrasonography for this purpose.

Methods: A high‐frequency (20 MHz) ultrasound A‐mode scanner was employed. Skinfold caliper recordings were performed for comparison. Frontal skin and skin of the back were studied in 7 infants with body weight 1095‐4750 g (also studied with B‐mode scanning). 46 infants weighing 925‐4120 g were studied and correlated with skinfold recording.

Results: A high degree of correlation between skinfold recordings and ultrasound measurements (A‐mode) of subcutaneous fat was found, coefficient of correlation 0.84, p<0.001.

Conclusions: High‐frequency ultrasound measurement of skin and subcutaneous fat thickness is precise and reliable for in vivo assessment of body fat in newborn infants. Further validation of the technique relative to neonatal skin and nutritional state is, however, needed before the ultrasound technique can be used as routine in neonatalogical monitoring.
Video‐optical monitoring of wheal and flare reactions
Authors: Steinmetz Jacob , Bjerring Peter
Published: October 2006

Background/aims: In order to monitor the dynamics of experimentally‐induced cutaneous inflammation in humans, we developed an objective, computerized video‐optical method for wheal and flare area determination.

Methods: The method was used for evaluation of PAF‐acether‐induced experimental inflammations on the volar aspect of the forearms of human volunteers. The study design was double‐blind, randomized, placebo‐controlled. Repeated measurements can be performed, e.g., with intervals of 1 min to reveal the time‐course of the inflammatory reaction. In the present study, the effect of topical application of creams containing 3 different concentrations of the putative anti‐inflammatory drug sodium sucrose‐sulphate (SoS) on cutaneous inflammation was investigated.

Results: 30 min after intracutaneous PAF‐acether injection, a statistically significantly increased (p<0.05) wheal area was found in skin sites treated by either 1%, 3% and 9% SoS cream, whereas no influence of sucrose‐sulphate could be demonstrated on the flare area. The reduction of the wheal area was significantly faster in the SoS‐treated areas than in the placebo (p<0.05).

Conclusions: Computerized video‐optical quantification of acute skin inflammatory reactions may be a suitable experimental tool for objective dynamic monitoring of both wheal and flare reactions and hence for quantification of the effect of anti‐inflammatory drugs in humans. Topical application of SoS surprisingly increased PAF‐acether‐induced skin oedema (wheal), significantly whereas no effect was found on the flare reaction. No concentration‐related effect of SoS could be shown.
EEMCO guidance for the assessment of dry skin (xerosis) and ichthyosis: clinical scoring systems
Authors: Serup Jørgen
Published: October 2006

Background/aims: Visual and tactile assessment of dry skin and ichthyosis is difficult and may vary. There is a need for standardized assessment according to universal scoring schemes.

Material and methods: A guidance to subjects (consumers) and experts evaluation with control of individual and other factors is presented. Scoring schemes include analogue scales, the overall dry skin score (ODS) and the specified symptom sum score (SRRC) system with grading of scaling, roughness, redness and cracks. The dry skin/ichthyosis area and severity index (DASI) is defined for dermatological evaluation of the entire skin surface. Conclusion: The EEMCO guidance is a practical research tool both for characterization of xerotic skin conditions and for efficacy substantiation of products. The guidance is developed to harmonize research in this field and improve interlaboratory comparison.
Squamometry in acute photodamage
Authors: Piérard G. E. , Piérard‐Franchimont C.
Published: October 2006

Background: Ultraviolet Irradiation has been shown to elicit alterations in corneocyte adhesion.

Purpose: To evaluate the early events in the changes of physical properties of the stratum corneum following a single ultraviolet B (UVB) irradiation.

Method: Squamometry (Chroma C* of D‐Squames) was used in 40 volunteers to assess the variations in stratum corneum cohesion during 3 consecutive days following 1.5 MED UVB irradiation on the forearms.

Results: Subjects with normal or moderately dry skin showed a significant increase in squamometry values during the 24 or 48 h following irradiation. Subjects with severe xerosis showed a progressive decrease in that value over time.

Conclusions: UV‐Squamometry is a convenient, rapid and sensitive method for evaluating the direct effect of UVB radiation on the stratum corneum.
Differentiation of involved and uninvolved psoriatic skin from healthy skin using noninvasive visual, colorimeter and evaporimeter methods
Authors: Pershing L. K. , Bakhtian S. , Wright E. D. , Rallis T. M.
Published: October 2006

Background/aims: Uninvolved skin of psoriasis may not be entirely normal. The object was to characterize healthy, uninvolved psoriatic skin and lesional skin by biophysical methods.

Methods: Involved and uninvolved psoriatic and age‐gender matched healthy skin was measured objectively with a colorimeter and evaporimeter and subjectively with visual assessment in 14 subjects.

Methods: Visual assessment of erythema (E), scaling (S) and induration (I) as well as the target lesion score at the involved psoriatic skin sites were significantly elevated (p<0.05) above uninvolved psoriatic or healthy skin sites. No difference between uninvolved psoriatic and healthy skin was measured visually. Transepidermal water loss at involved psoriatic skin >uninvolved psoriatic skin >healthy skin (p<0.05). Objective assessment of skin color in 3 color scales, L*, a*, and b*, differentiated involved and uninvolved psoriatic skin from healthy skin sites. Involved psoriatic skin demonstrated higher (p<0.01) a‐scale values and lower (p<0.01) L* and b* scale values than uninvolved psoriatic skin. Further, colorimeter L* and a* scale values at uninvolved psoriatic skin sites were lower and higher (p<0.05), respectively, than healthy skin. The individual chromameter parameters (L*, a*, b*) correlated well with the visual parameters (E, S and I). Composite colorimeter description (L*× b*)/a* significantly differentiated healthy skin from both involved and uninvolved psoriatic skin.

Conclusions: These collective data highlight that even visually appearing uninvolved psoriatic skin is compromised compared with healthy skin. These objective, noninvasive but differential capabilities of the colorimeter and evaporimeter will aid in the mechanistic quantification of new psoriatic drug therapies and in conjuction with biochemical studies, add to understanding of the multifactorial pathogenesis of psoriasis.
Non‐invasive assessment of the antipsoriatic activity of fumaric acid derivatives
Authors: Hoffmann K. , Dirschka Th. , Schwarze H. , Stücker M. , Matthes U. , El‐Gammal S. , Hoffmann A. , Altmeyer P.
Published: October 2006

Background/aims: Noninvasive methods are introduced for the monitoring of healing of psoriasis. Fumaris acid derivatives (FAD) were used in the treatment of psoriasis vulgaris for more than 30 years, but the effectiveness of these drugs has remained controversial. The object was to study the efficacy of FAD in a prospective study including noninvasive techniques, which may allow more accurate assessment in a smaller patient group.

Methods: High‐frequency ultrasound including image analysis, and colorimetry was employed. 14 patients were treated for 20 weeks.

Results: In the ultrasound image, acanthosis and inflammatory infiltrate of active psoriasis cause an echopoor area under the entry echo. Under theray, this echo area diminishes while its density increases. During healing, the decrease in redness could be quantified.

Conclusions: Monitoring of the healing of psoriasis is possible with ultrasonography and colorimetry. Fumaric acid was found efficient and safe in the treatment of psoriasis.
Image analysis for quantification of nucleolar organizer regions in basal cell carcinoma and seborrheic keratosis
Authors: Lee Sung Yul , Lee Jong Suk , Oh Chil Hwan
Published: October 2006

Background/aims: Nucleolar organizer regions (NORs) have recently attracted much attention because of claims that their frequency within nuclei is significantly higher in malignant cells than in normal, reactive, or benign neoplastic cells. The purpose of this paper is to analyze a method allowing selection of the best morphometric criterion for quantifying AgNORs (Silver stained Nucleolar organizer Regions) under conventional observation conditions, by light microscopy.

Methods: The various parameters including NORs counting in cutaneous tumors using image analysis system were studied.

Results: There were significant differences in mean numbers of AgNORs per nucleus, mean ratio of AgNORs area per nucleus area, mean ratio of greatest AgNORs area per nucleus area, mean nucleus area per a AgNOR, and CV (Coefficient of Variation) of AgNORs area between basal cell carcinoma and seborrheic keratosis.

Conclusion: Study of AgNORs using the image analysis system is a useful tool for diagnosis of cutaneous tumors.
Karyometry of malignant melanoma cells present in skin strippings
Authors: Piérard Gérald E. , Ezzine‐Sebai Nadia , Fazaa Bécima , Nikkels‐Tassoudji Nazli , Piérard‐Franchimont Claudine
Published: October 2006

Background/aims: Skin strippings harvest the malignant melanoma cells eliminated through the stratum corneum. In this study, morphometry was applied to such non‐invasive samplings in order to derive objective information about nuclear atypia.

Method: Cyanoacrylate skin surface strippings were collected from 140 malignant melanomas. Karyometry was performed to quantify the size and shape of malignant cell nuclei.

Results: Anisokaryosis was prominent although the outline of nuclei were rather smooth.

Conclusion: Image analysis of skin strippings harvested from malignant melanomas shows that anisokaryosis is the major cytologic feature of malignant melanoma cells in transit in the stratum corneum.
Computerized evaluation of pigmented skin lesion images recorded by a videomicroscope: comparison between polarizing mode observation and oil/slide mode observation
Authors: Seidenari Stefania , Burroni Marco , Dell'Eva Giordana , Pepe Patrizia , Belletti Barbara
Published: October 2006

Background/aims: It has now been established that ELM significantly improves the clinical diagnosis of pigmented skin lesions, particularly when associated with image analysis on digital pictures.

Besides surface microscopes, so called “videomicroscopes” are nowadays commercially available. Thanks to their practicality and to their reasonable price and small volume, they could be usefully employed by general practitioners or peripheral dermatologists in their practice. The aim of our study was to evaluate the usefulness and the handiness of a videomicroscope provided with polarized light, and to compare images recorded in the polarizing mode to those of the same lesions recorded after application of oil and a glass slide.

Methods: 114 images of benign pigmented skin lesions were recorded both in polarizing mode and in oil/slide mode observation. Digital images were then analyzed by means of a dedicated software, evaluating 34 different parameters.

Results: The instrument is easy to handle and the acquisition of images is simple and quick. Polarizing mode observation enables the recognition of subsurface structures, like pigment network and capillaries. Red and blue components in the images tend to be more pronounced, when images are acquired by the polarizing system, whereas green components are prominent in oil images. Values referring to dark areas are also higher for oil images. However, the 2 observation modes provide digital images, whose values, in most cases, do not differ statistically.

Conclusion: Videomicroscopes are cheap, space saving, and enable a quick examination of skin areas to be imaged. The possibility of a rapid switch from surface to subsurface polarizing mode observation, makes the examination procedure even faster. Our data demonstrate that polarizing mode observation and recording can be employed as a basis for clinical and computerized epiluminescence, particularly in situations, where a rapid screening of numerous patients and lesions is necessary.
Storage and retrieval of digital images in dermatology*
Authors: Bittorf A. , Krejci‐Papa N. C. , Diepgen T. L.
Published: October 2006

Background: Differential diagnosis in dermatology relies on the interpretation of visual information in the form of clinical and histopathological images. Up until now, reference images have had to be retrieved from textbooks and/or appropriate journals. To overcome inherent limitations of those storage media with respect to the number of images stored, display, and search parameters available, we designed a computer‐based database of digitized dermatologic images.

Methods: Images were taken from the photo archive of the Dermatological Clinic of the University of Erlangen. A database was designed using the Entity‐Relationship approach. It was implemented on a PC‐Windows platform using MS Access* and MS Visual Basic®. As WWW‐server a Sparc 10 workstation was used with the CERN Hypertext‐Transfer‐Protocol‐Daemon (httpd) 3.0 pre 6 software running.

Results: For compressed storage on a hard drive, a quality factor of 60 allowed on‐screen differential diagnosis and corresponded to a compression factor of 1:35 for clinical images and 1:40 for histopathological images. Hierarchical keys of clinical or histopathological criteria permitted multi‐criteria searches. A script using the Common Gateway Interface (CGI) enabled remote search and image retrieval via the World‐Wide‐Web (W3).

Conclusions: A dermatologic image database, featurig clinical and histopathological images was constructed which allows for multi‐parameter searches and world‐wide remote access.
Echographic assessment of corticosteroid‐induced skin‐thinning, including echogenicity measurement
Authors: Richard S. , Duteil L. , Poli F. , de Rigal J. , Querleux B. , Queille‐Roussel C. , Lévêque J. L. , Revuz J.
Published: October 2006

Background/aims: Skin atrophy is one of the main side effects of long‐term topical corticosteroid therapy. It has already been studied through ultrasound skin‐thickness measurement. In this study, the quantification of dermal echogenicity was introduced to provide new information on this phenomenon.

Methods: Skin thinning induced by topical application (without occlusion) of the superpotent corticosteroid clobetasol propionate (0.05% lotion), was assessed by means of ultrasonography in terms of thickness and echogenicity. 15 healthy volunteers were treated for 6 weeks, 1 daily, 5 days a week on the forearms.

Results: The thinning showed a biphasic pattern, with a 1st period of rapid change (about 15% of thinning in a week) followed by a period of slower but significant change. Skin thickness returned to baseline values 3 weeks after the end of treatment. Dermal echogenicity, which represents the mean intensity of the ultrasound signals reflected by the dermis, was found to follow the same variations, increasing strongly during the 1st week, then more slowly. The 2 parameters are correlated and probably reflect the same physiological modifications responsible for skin thinning, i.e., a reduction in glycosaminoglycan synthesis (leading to a drastic fall in dermal water content) and vasoconstriction.

Conclusion: This sensitive and non invasive method enables us to identify the effects of clobetasol propionate on the healthy dermis in the absence of any clinical signs of thinning.
The effect of probe depth on histamine levels in humans. In vivo cutaneous microdialysis
Authors: Andersson Thomas , Svensson Catherine , Anderson Chris
Published: October 2006

Background/aims: Microdialysis technique, for the in vivo estimation of endogenous and exogenous substances in tissues, is gaining increasing use in human experimentation. The cutaneous microdialysis technique has interesting applications in several fields, including the study of skin inflammation and percutaneous absorption. One of the aspects of cutaneous microdialysis which needs clarification is the influence on results of the exact position of the microdialysis probe in the dermis.

Methods: In a total material of 67 histamine experiments, probe depth has been measured by the ultrasound technique. In 24 uniform experiments, histamine values at 10‐min intervals after probe insertion and prior to other provocation have been analyzed in relation to probe depth.

Results: The mean probe depth was 1.1 mm (range 0.8‐1.9 mm). In regression analysis of histamine values in 10‐min intervals up to 90 min after probe insertion in relation to probe depth, the histamine values were found to be independent of probe depth. This may be due to rapid local diffusion of histamine, together with axon reflex mediated histamine release. Further analysis revealed no correlation between histamine results and the subject's age, sex or presence of atopy.

Conclusion: The present results indicate that the exact placement of the microdialysis probe into the dermis is not too critical in experiments where histamine is to be studied. It must be pointed out that the same may not necessarily be true of other inflammatory mediators: for each new target substance and application, the influence of probe placement needs to be considered.