bluuebunny/crossref_metadata_2025 huggingface dataset:
Tail Conditional Expectations for Exponential Dispersion Models
Authors: Landsman Zinoviy , Valdez Emiliano A.
Published: June 2005

There is a growing interest in the use of the tail conditional expectation as a measure of risk. For an institution faced with a random loss, the tail conditional expectation represents the conditional average amount of loss that can be incurred in a fixed period, given that the loss exceeds a specified value. This value is typically based on the quantile of the loss distribution, the so-called value-at-risk. The tail conditional expectation can therefore provide a measure of the amount of capital needed due to exposure to loss. This paper examines this risk measure for “exponential dispersion models”, a wide and popular class of distributions to actuaries which, on one hand, generalizes the Normal and shares some of its many important properties, but on the other hand, contains many distributions of nonnegative random variables like the Gamma and the Inverse Gaussian.
Cooperative Learning in Italian Secondary School
Authors: Martino Emilia Di
Published: June 2005

This paper presents the results of an Action Research project aimed at exploring (1) the possibility of implementing Cooperative Learning and (2) the possible benefits of doing so in the author’s specific teaching situation at Upper Secondary level in Italy.
Beyond Questionnaires
Authors: Peköz Bayram
Published: June 2005

The aim of this study was to investigate language learning motivation within an educational approach. Within this framework, the present study investigated learners’ actual classroom motivation as opposed to GARDNER’s (1985) self-report motivation. Two AMES (Adult Migrant English Service) classes were observed for 11 weeks each, totalling 72 hours altogether. The observations were carried out through an observation scale designed to rate learners’ motivation. A questionnaire which was based on GARDNER’s (1985) ‘Attitude and Motivation Index’ was also administered to test Gardner’s socio-psychological approach to second language (SL) motivation. The study confirmed the hypotheses, which had predicted that there was no relationship between a) attitudes towards the target language commulllty and actual classroom motivation; and b) self-report motivation and observed classroom motivation.
Terminology in Interlanguage Pragmatics
Authors: Tran Giao Quynh
Published: June 2005

Inter language pragmatics research has spanned a number of different areas in second language acquisition and pragmatics. In the large corpus of interlanguage pragmatics studies, basic terms such as “interlanguage pragmatics”, “speech acts” and “pragmatic transfer” have been referred to more often than not. But rarely have we stopped to re-evaluate the applicability and appropriateness of these terms. This paper aims to properly interpret or redefine their meanings and to propose more appropriate terms where possible.
Edad y Competencia Oral en la Adquisición del Inglés Como Tercera Lengua
Authors: Zarobe Yolanda Ruiz De
Published: June 2005

EI presente trabajo estudia el desarrollo de la competencia oral en la adquisición del inglés como tercera lengua. Específicamente, analiza la influencia que la edad puede ejercer en el desarrollo de la competencia oral por parte de niños bilingües de español-euskera. Para llevar a cabo esta investigación, hemos contado con un corpus de 81 alumnos de una ikastola privada de Gipuzkoa, divididos en tres grupos según la edad, aunque con un mismo período de instrucción en inglés. Los resultados de nuestro estudio indican que son los alumnos más jóvenes los que presentan ventajas en el desarrollo de su competencia oral. Este hecho puede deberse a la metodología seguida en el aula, que es fundamentalmente comunicativa con los grupos de menor edad.
Effect of Biomaterial Surface Morphologies on Bone Marrow Cell Performance
Authors: Bruinink A. , Kaiser J.‐P. , Meyer D. C.
Published: May 2005

The biological reaction on implant surfaces is of key importance for the integration of implants into the surrounding tissue. In the present study, a new set‐up for the preparation of different surfaces with identical surface chemistry is presented. Using this technique, we investigated the effects of surface microstructuring on cell performance using adult, rat bone marrow cells as a tool. Our results indicate that cell morphology was strongly affected by the kind of surface microstructuring. Effects on cell culture biochemical characteristics did not always correlate with effects on cell morphology and cell culture appearance.
Influence of Burner Scale‐up on Characteristics of Flame‐Synthesized Titania and Silica Nanoparticles
Authors: Dittmann R. , Richter J. , Vital A. , Piazza D. , Aneziris C. , Graule T.
Published: May 2005

The influence of geometrically‐similar upscaling of a laboratory diffusion flame burner on the morphology, specific surface area and phase composition of titania and silica nanoparticles has been investigated. For these two materials systems, two flame configurations were studied using both a laboratory‐size and an upscaled burner. Independent of the burner size, smaller and more aggregated particles form in the double diffusion flame, while spherical particles result from the single diffusion flame. The titania and silica powders produced in the upscaled burner have a lower specific surface area and are less homogeneous, despite being synthesized at the same overall flame stoichiometry and gas outlet velocities as used with the laboratory burner. These results can be explained by the increase in flame height, which causes the residence time of the growing particles in the high‐temperature flame to increase. The larger single diffusion flame stems from the longer radial diffusion paths between the reactant gases in the upscaled burner.
Cover Picture: Nanotechnology: An Approach to Mimic Natural Architectures and Concepts (Adv. Eng. Mater. 5/2005)
Authors: Gröning P. A.
Published: May 2005

The lotus leaf's ability for self‐cleaning is considered as a model to produce dust‐ and dirt‐repellent surfaces, e.g. “anti‐graffitti” spray. This cover picture shows a water droplet condensing on the leaf surface and lifting up graphite particles (from ESEM in‐situ experiments). Further examples how researchers try to mimic nature are described in the article “Nanotechnology: An approach to mimic natural architectures and concepts” by P. A. Gröning on page 279.

With the invention of the Scanning Tunnelling Microscope (STM) in 1981 by G. Binnig and H. Rohrer, the gate to the nanoworld was pushed open. The prospect to control matter and units on molecular and atomic level, inspired many scientists to think about new technological approaches – nanotechnology in the sense of Richard Phillips Feynman became reality. Thus, nanotechnology is not only the next step of the miniaturisation following microtechnology – nanotechnology is an approach to investigate natural architectures and to mimic them for technological problems. In the present article we try to show that nanotechnology is an evolutionary process of our technological society with the potential to solve everyday problems with revolutionary concepts and devices.
Effect of plasma exchange on cytokines measured by multianalyte bead array in thrombotic thrombocytopenic purpura
Authors: Shariatmadar Sherry , Nassiri Mehdi , Vincek Vladimir
Published: May 2005

The serum cytokine profile in thrombotic thrombocytopenic purpura (TTP) has not been extensively characterized. In this pilot study, a novel technique was utilized to evaluate multiple cytokines in patients with idiopathic TTP during a course of plasma exchange (PE). Single serum samples were obtained from five TTP patients before and after each PE. Random sera were obtained from nine healthy volunteers who served as controls. The samples were evaluated for 13 cytokines (IL‐1B, IL‐2 , IL‐4, IL‐5, IL‐6, IL‐7, IL‐8, IL‐10, IL‐12, IL‐13, IFN‐γ, GM‐CSF, and TNF‐α) using the Luminex bead array (LINCOplex) multianalyte detection system that permits simultaneous detection of multiple cytokines from a single sample. Each patient received 4–6 PEs (Cobe Spectra) with 3.0–4.0 L of fresh frozen plasma as replacement fluid. Four of 5 patients received corticosteroids prior to and during PE. The control group did not receive steroids. Baseline values for IL‐8 (182.9 vs. 6.5 pg/mL, P < 0.05) and TNF‐α (11.4 vs. 0.9 pg/mL, P < 0.001) were significantly higher in TTP patients compared with controls. Other tested cytokines were not significantly different between the two groups. Comparison of cytokine values pre‐ and post‐PE indicate a substantial decrease after each PE. However, cytokines rebounded to abnormal levels by the following day. There was no correlation between cytokines and serum LDH or platelet count. These findings suggest that certain cytokines, particularly IL‐8 and TNF‐α, are altered in TTP, and this may indicate a direct role in TTP pathogenesis, reflect ongoing tissue injury, or perhaps indicate an inadequate attempt to limit tissue injury. Am. J. Hematol. 79:83–88, 2005. © 2005 Wiley‐Liss, Inc.
Spectrin's E2/E3 ubiquitin conjugating/ligating activity is diminished in sickle cells
Authors: Chang Tsui‐Ling , Kakhniashvili David G. , Goodman Steven R.
Published: May 2005

Erythrocyte spectrin contains E2/E3 ubiquitin conjugating/ligating activity in its α subunit. Ankyrin is a target of spectrin's E2/E3 ubiquitin conjugating/ligating activity in vitro and in vivo. We compare the ubiquitination levels of ankyrin mediated by control and sickle cell spectrin using a biotinylated ubiquitin cell‐free assay. Sickle cell spectrin has diminished ability to transfer ubiquitin from an intermediate spectrin–ubiquitin thioester adduct (α′ spectrin) to ankyrin, which may be due to glutathiolation of spectrin's E2 and/or E3 active site cysteines. There is also a diminished ability of the sickle cell ankyrin to serve as target of spectrin's E2/E3 activity, probably due to oxidative damage to ankyrin. A direct correlation exists between the α′/α spectrin ratio and spectrin's ability to ubiquitinate ankyrin. There is also an inverse correlation between severity of the disease and the α′/α spectrin ratio in SS erythrocytes. These results suggest that reduced spectrin E2/E3 activity is an important determinant of sickle cell severity. Am. J. Hematol. 79:89–96, 2005. © 2005 Wiley‐Liss, Inc.
Ultralow‐Dielectric‐Constant foams by crystallisation from supercritical solution: Application to advanced electronic packaging
Authors: Ehrlich P. , Ehrlich D. J.
Published: May 2005

Accurate moulding of polymer foams of density 0.02–0.3 g cm−3 has been achieved by crystallising polyethylene and ethylene/methlacrylate copolymers from dry supercritical solutions. Adherent thick films can be sealed to electronic substrates and are proposed as insulating layers for interconnections on multichip modules and other high‐speed electronic devices. The dielectric constant achieved for films of several‐mil thickness is between 1.05 and 1.3 and can be tailored along with the physical properties of the film by adjusting the density and composition of the copolymer. Planarisation or complex patterning is possible by detailing the mould.
Photophysical processes in low‐fluence UV laser–material interaction and the relevance to atomic layer processing
Authors: Helvajian H. , Wiedeman L. , Kim H.‐S.
Published: May 2005

Atomic‐scale material‐processing tools must be developed to allow the in situ synthesis of complex, nanometre‐scale, multilayer structures. These processing tools must be cost‐effective, extendible to large‐area surfaces and adaptable to realistic manufacturing equipment. Presented here are experimental results on the photophysical processes in low‐fluence UV laser radiation of surfaces. The results suggest that atomic‐level synthesis/modification of materials is possible by the laser‐induced desorption by electronic excitation (LIDEE) process. The processing action employs resonance behaviour to gain species selectivity in the products desorbed. It naturally lends itself to automation (pulsed processing) and is designed for manufacturing laser systems currently used in materials processing. In addition, no potential limitations exist on the surface area which can be processed. Presented are the experimental data using crystalline Al and Bi2Sr2Ca1Cu2O8 targets along with supporting results from Ag and W targets. The results are interpreted in the light of photodesorption models which best support the data. As a conclusion we present an outline of how the LIDEE process might be used as a nanometre‐scale material‐processing tool.
Laser direct writing of gold conductors from metallorganic inks
Authors: Scelsi G. B. , Notaro J. , Arnone C.
Published: May 2005

Laser deposition of gold lines from spin‐on metallorganic (MO) precursors has been studied. A readily available and relatively low‐cost commercial MO ink has been used to write gold interconnects on different substrates. The physical properties of the ink, its laser‐firing process on oxidised silicon substrates and its electrical characterisation are presented here, together with the experimental procedure needed for obtaining low‐resistivity deposits.
Optical non‐linearities and excitation dynamics in II–VI bulk and epitaxial materials
Authors: Gutowski J. , Hoffmann A.
Published: May 2005

Excitonic processes in the band edge regime determine the optical properties of II–VI bulk and novel epitaxial materials. The interdependences of excitonic systems (i.e. free and bound excitons), high‐density systems (e.g. biexcitons) and the transition into the electron‐hole plasma state are of high complexity and depend sensitively on sample quality and purity, dopant concentration, excitation condition and density, etc. Resonant excitation spectroscopy and time‐resolved analysis of creation and decay processes provide valuable experimental access to clarification of the above‐mentioned mutual interactions. In this paper recent results obtained using these methods are surveyed.

In the first part the development of luminescence and resonant excitation of bound exciton systems is treated under various excitation densities, for high excitation levels accompanied by biexciton formation and exciton–exciton collision processes. The specific properties observable when using heteroepitaxial structures instead of conventional bulk samples are discussed.

In the second part the time characteristics of excitonic transitions are evaluated for various impurities, dopants and dopant concentrations, excitation via particular resonant excitation channels, and various excitation densities. Relaxation and conversion channels between excitonic systems are analysed, in particular in strained heteroepitaxial systems which show splitting effects of the bands from which the carriers stem. Time‐resolved analysis is demonstrated to be extremely helpful for the analysis of unknown excitonic systems and transitions. Methods of varying the characteristic time constants are discussed, in particular with regard to intentional changes in impurity contents and excitation densities which are interesting for any application.
Identification of the volatile decomposition products produced in the deposition of (Hg,Cd)Te by MOVPE
Authors: Hails Janet E.
Published: May 2005

The pyrolysis reactions of di‐isopropyl telluride and dimethyl cadmium, both alone and in combination and with and without mercury, have been studied using the technique of gas chromatography–mass spectrometry (GC–MS). For example, when mercury and dimethyl cadmium are mixed in hydrogen at the growth temperature (370°C), the volatile products observed are methane, ethane and dimethyl mercury. In contrast, when di‐isopropyl tellurideis substituted for the cadmium precursor in this reaction, the products observed are propane, propene and 2,3‐dimethylbutane with no volatile mercury‐containing compounds. Heating the two organometallic precursors together at the growth temperature in the absence of mercury gives products expected from the pyrolysis of each one alone plus a number of interaction products such as 2‐methylpropane. The results of these studies will be presented, a mechanism for the reactions proposed and the implications for MOVPE growth discussed.
MOVPE growth and characterization of ZnSxSe1 − x/ZnSe quantum wells
Authors: Heuken M. , Söllner J. , Geyzers K. P. , Schneider A. , Guimarães F. E. G.
Published: May 2005

In this work we report on ZnSxSe1 − x/ZnSe quantum wells grown by atmospheric pressure MOVPE on GaAs substrates. Diethylznc (DEZn), diethylselenium (DESe), diethylsulphur (DES) and H2S were used as source materials. Binary quantum wells with ZnSe or ZnS as barrier were usually grown in sets of 10 pairs on a 0.5 μm ZnSe or ZnS buffer, respectively. QWs with different well thicknesses (1–4 nm) show a typical shift to higher energies with decreasing well thickness and also a large decrease in PL intensity with increasing well thickness. Owing to the onset of relaxation above 5 nm well thickness, no PL emission could be observed. QWs of the same thickness but grown at different temperatures (420–520°C) show a broadened line shape with decreasing growth temperature. Growth interruption (3–50 s) also causes a broadening of the PL emission with decreasing interruption time. This is caused by interface reconstruction at higher growth temperatures and longer growth interruption. A ZnS buffer of 0.5 μm improves the PL line shape compared with a ZnSe buffer.

ZnSxSe1 − x/ZnSe single and multiple QWs (Lz = 1–4 nm) were grown to reduce the strain in the structures. A typical quantum confinement energy shift of 160 meV for the 1 nm well can be observed in ZnS0.68Se0.32/ZnSe QWs. In comparison with the binary QWs, the FWHM could be reduced by about a factor of two to 34 meV. This improvement was obtained by an optimisation of the switching process to prevent the desorption of sulphur from the ZnSSe during the growth interruption.
Defect‐induced fundamental edge distoritons in two‐photon spectroscopy of semiconductors
Authors: Gavryushin V. I. , Kazlauskas A. , Račiukaitis G.
Published: May 2005

The influence of grown‐in and impurity defects on the form of the fundamental absorption edge in ZnO, ZnSe and CdS crystal was studied by the method of two‐photon absorption (TPA). A considerable long‐wavelength shift of the TPA spectra was measured in Zinc‐rich compounds after thermal treatment. This can be explained by a very good saturation of interstitial Zni atoms up to a concentration of 1018 cm−3 causing deformation of the band edge.
Preparation and electroluminescence of CaS: (Ce, Eu and Cu) phosphors
Authors: Arterton B. W. , Viney I. V. F. , Ray B. , Brightwell J. W.
Published: May 2005

Doped CaS powder samples were prepared using two methods: (i) a metathesis reaction of carbonate with H2S at 1200°C; (ii) reaction with Na2Co3/S flux at 1000°C in nitrogen, followed by washing in an alkaline solution, drying and sieving to give 20–30 μm particles.

Powders produced from both reactions were strongly photoluminescent and singificant AC electroluminescence (ACEL) was observed when samples produced by the metathesis reactions were copper coated. Samples prepared using the flux technique on pre‐copperdoped carbonate also showed ACEL.

The EL excitation process in the flux grown material differs from that in samples prepared using H2S; this stems from Cu2S microdeposits on the particle surfaces of the former. The formation of the needle‐like deposit results from precipitation of copper from solid solution with decreasing temperature. The EL emission arises from observable point sources rather than the more uniform emission from copper‐coated samples.
ZnCdS films for solar cell and photodetector applications deposited by In Situ chemical doping of CdS with Zn
Authors: Sebastian P. J.
Published: May 2005

ZnCdS films were formed by in situ chemical doping of CdS with Zn in a chemical bath. The X‐ray diffraction (XRD) patterns of CdS films after Zn doping showed a more disordered nature, consisting of reflections from Zn0.049Cd0.951S (JCPDS 40‐834) as well as CdS greenockite (hexagonal, JCPDS 41‐1049) and hawleyite (cubic, JCPDS 10‐0454) phases. A comparison of the optical transmittance spectra for undoped and Zn‐doped films showed that the cut‐off wavelength was modified after Zn doping, indicating the presence of impurity states in the band gap. Zn‐doped films showed an increase in dark conductivity after annealing at about 200°C. These films exhibit promising characteristics for application in solar cell and photodetector structures.
Electrical, optical and photoelectrochemical properties of natural enargite, Cu3AsS4
Authors: Pauporté Th. , Lincot D.
Published: May 2005

The semiconducting properties of natural samples of enargite, a copper and arsenic suphide (Cu3AsS4), have been studied. They have been found to be p‐type semiconductors with a resistivity of about 7 Ω cm, a doping level of about 1017 cm−3 and a mobility of 9 cm2V−1 s−1. The variation of the resistivity as a function of temperature allows to determine an activation energy of 0.11 eV. Two optical transitions have been determined, an indirect one at 1.19 eV and a direct one at 1.44 eV. The samples, mounted as working electrodes in a photoelectrochemical set‐up, are photosensitive and behave as p‐type photocathodes. The two transitions are found again from the analysis of photocurrent spectra. The direct band gap value is close to the ideal value required for photovoltaic applications. However the quantum efficiencies obtained here are still low.
Titelbild: Metallionen als Cofaktoren bei der Hemmstoffbindung an Methionin‐Aminopeptidase: eine kritische Betrachtung von In‐vitro‐Metalloenzym‐Assays (Angew. Chem. 23/2005)
Authors: Schiffmann Rolf , Heine Andreas , Klebe Gerhard , Klein Christian D. P.
Published: May 2005

Metalloenzyme werden oft in Gegenwart von unphysiologisch hohen Metallkonzentrationen untersucht. Dies kann zu Artefakten beim Test von Hemmstoffen führen, wenn die Bindung eines Hemmstoffs erst durch ein zusätzliches Metallion ermöglicht wird – solche Verbindungen können in vitro sehr potent sein, weisen aber keine In‐vivo‐Aktivität auf. C. D. P. Klein und Mitarbeiter beschreiben diesen Effekt am Beispiel des Enzyms Methionin‐Aminopeptidase in ihrer Zuschrift auf S. 3686 ff. (Die Abbildung der Maus stammt vom U.S. Natl. Park Service.)
Clinical relevance of the expression of P‐glycoprotein on peripheral blood lymphocytes to steroid resistance in patients with systemic lupus erythematosus
Authors: Tsujimura Shizuyo , Saito Kazuyoshi , Nakayamada Shingo , Nakano Kazuhisa , Tanaka Yoshiya
Published: June 2005

Objective

P‐glycoprotein (P‐gp) of membrane transporters leads to drug resistance by the exclusion of intracellular drugs, including corticosteroids. Some patients with highly active systemic lupus erythematosus (SLE) show poor response to corticosteroids; however, the mechanisms of steroid resistance remain unclear. The aim of this study was to elucidate the clinical relevance of P‐gp expression on lymphocytes to steroid resistance in patients with active SLE.

Methods

Flow cytometric analyses of the expression of P‐gp on peripheral blood lymphocytes from 20 normal volunteers and 80 SLE patients were performed. Steroid‐exclusion analysis of peripheral blood mononuclear cells (PBMCs) was conducted by using radioisotope‐labeled dexamethasone.

Results

P‐gp was expressed at significantly high levels on most of the peripheral blood lymphocytes from SLE patients, whereas normal lymphocytes had only marginal expression. The quantity of P‐gp on SLE lymphocytes correlated with the disease activity in each patient, as estimated by the Systemic Lupus Erythematosus Disease Activity Index (SLEDAI). Furthermore, in SLE patients whose SLEDAI scores were >12 despite taking >0.5 mg/kg/day of prednisolone, P‐gp expression on lymphocytes was markedly increased, and intracellular dexamethasone in their PBMCs was significantly decreased. However, intensive immunosuppressive treatment in these SLE patients resulted in successful control of disease activity, which occurred in parallel with a marked reduction of P‐gp on lymphocytes.

Conclusion

The overexpression of P‐gp on lymphocytes might lead to exclusion of corticosteroids from lymphocytes, resulting in steroid resistance in patients with highly active SLE. Reduction of P‐gp expression achieved by intensive immunosuppressive treatment overcame the steroid resistance. We therefore propose that measurement of P‐gp expression on lymphocytes is useful in the assessment of steroid resistance and is a good marker for indicating the need for intensive immunosuppressive treatment in patients with highly active SLE.
Amelioration of rat adjuvant‐induced arthritis by Met‐RANTES
Authors: Shahrara Shiva , Proudfoot Amanda E. I. , Woods James M. , Ruth Jeffrey H. , Amin M. Asif , Park Christy C. , Haas Christian S. , Pope Richard M. , Haines G. Kenneth , Zha Yuan Yuan , Koch Alisa E.
Published: June 2005

Objective

CC chemokines and their receptors play a fundamental role in trafficking and activation of leukocytes at sites of inflammation, contributing to joint damage in rheumatoid arthritis. Met‐RANTES, an amino‐terminal–modified methionylated form of RANTES (CCL5), antagonizes the binding of the chemokines RANTES and macrophage inflammatory protein 1α (MIP‐1α; CCL3) to their receptors CCR1 and CCR5, respectively. The aim of this study was to investigate whether Met‐RANTES could ameliorate adjuvant‐induced arthritis (AIA) in the rat.

Methods

Using immunohistochemistry, enzyme‐linked immunosorbent assay, real‐time reverse transcription–polymerase chain reaction, Western blot analysis, adoptive transfer, and chemotaxis, we defined joint inflammation, bony destruction, neutrophil and macrophage migration, Met‐RANTES binding affinity to rat receptors, proinflammatory cytokine and bone marker levels, CCR1 and CCR5 expression and activation, and macrophage homing into joints with AIA.

Results

Administration of Met‐RANTES as a preventative reduced the severity of joint inflammation. Administration of Met‐RANTES to ankles with AIA showed decreases in inflammation, radiographic soft tissue swelling, and bone erosion. Met‐RANTES significantly reduced the number of neutrophils and macrophages at the peak of arthritis compared with saline‐injected controls. Competitive chemotaxis in peripheral blood mononuclear cells demonstrated that Met‐RANTES inhibited MIP‐1α and MIP‐1β at 50% inhibition concentrations of 5 nM and 2 nM, respectively. Furthermore, levels of tumor necrosis factor α, interleukin‐1β, macrophage colony‐stimulating factor, and RANKL were decreased in joints with AIA in the Met‐RANTES group compared with the control group. Interestingly, the expression and activation of CCR1 and CCR5 in the joint were down‐regulated in the Met‐RANTES group compared with the control group. Functionally, Met‐RANTES administration decreased adoptively transferred peritoneal macrophage homing into the joint.

Conclusion

The data suggest that the targeting of Th1‐associated chemokine receptors reduce joint inflammation, bone destruction, and cell recruitment into joints with AIA.
Effects of combination M40403 and dexamethasone therapy on joint disease in a rat model of collagen‐induced arthritis
Authors: Cuzzocrea Salvatore , Mazzon Emanuela , Paola Rosanna Di , Genovese Tiziana , Muià Carmelo , Caputi Achille P. , Salvemini Daniela
Published: June 2005

Objective

To investigate the effects of combination therapy with M40403, a superoxide dismutase mimetic (SODm), and dexamethasone (DEX) on collagen‐induced arthritis (CIA) in rats.

Methods

CIA was elicited in Lewis rats by an intradermal injection of 100 μl of an emulsion of bovine type II collagen (CII) in Freund's incomplete adjuvant (IFA) at the base of the tail. On day 21, a second injection of CII in IFA was administered at the base of the tail.

Results

Lewis rats developed erosive arthritis of the hind paw when immunized with an emulsion of CII in IFA. The histopathology of CIA included erosion of the articular cartilage at the joint margins and subchondral bone resorption. Immunohistochemical analysis for nitrotyrosine, poly(ADP‐ribose) polymerase (PARP), inducible nitric oxide synthase (iNOS), and cyclooxygenase 2 (COX‐2) revealed positive staining in inflamed joints of collagen‐treated rats. The combination therapy with M40403 2 mg/kg and DEX 0.01 mg/kg significantly reduced the development of the inflammatory process and reduced the degree of staining for iNOS, COX‐2, nitrotyrosine, and PARP. No significant difference in the degree of staining between the combination therapy and the higher dose of DEX (0.1 mg/kg) was found. Furthermore, radiographic evidence of protection from bone resorption was apparent in the tibiotarsal joints of rats that received the combination therapy.

Conclusion

This study shows that combination therapy with M40403 and DEX reduced the degree of chronic inflammation and tissue and bone damage associated with CIA in the rat. It supports the possible use of SODm in combination with steroids to reduce the dose necessary and the side effects related to the use of steroids in the management of chronic diseases such as rheumatoid arthritis.
Interaction of pyrin with 14.3.3 in an Isoform‐specific and phosphorylation‐dependent manner regulates its translocation to the nucleus
Authors: Jéru Isabelle , Papin Stéphanie , L'Hoste Sébastien , Duquesnoy Philippe , Cazeneuve Cécile , Camonis Jacques , Amselem Serge
Published: June 2005

Objective

Pyrin, the familial Mediterranean fever gene product, exists in several isoforms of unknown functions. The recombinant full‐length isoform (pyrin.fl) is cytoplasmic, whereas an alternatively spliced isoform lacking exon 2 (pyrin.ΔEx2) concentrates in the nucleus. Native pyrin, mainly consisting of pyrin.fl, is also cytoplasmic in monocytes but is predominantly nuclear in other cell types. To understand pyrin‐dependent biologic pathways and to decipher the mechanisms accounting for such different patterns of subcellular compartmentalization, binding partners and posttranslational modifications of pyrin were assessed.

Methods

A yeast 2‐hybrid screen was performed with pyrin.fl as the bait. The interaction identified between pyrin.fl and 14.3.3 proteins was confirmed by immunoprecipitation of 35S‐radiolabeled protein complexes; similar experiments were performed with pyrin.ΔEx2, pyrin.fl after alkaline phosphatase treatment, and pyrin.fl mutants in which several exon 2–encoded serine residues were replaced by nonphosphorylatable alanines. The subcellular localization of the different wild‐type and mutated pyrin proteins was assessed by immunofluorescence.

Results

Two members of the 14.3.3 protein family were identified as pyrin partners. Whereas pyrin.fl interacted with 14.3.3τ and 14.3.3ϵ, these interactions did not occur with pyrin.ΔEx2. Pyrin.fl was phosphorylated, and this modification mediated 14.3.3 binding. Serines 208, 209, and 242, within exon 2, acted as critical residues in the interaction between pyrin.fl and 14.3.3. When an S208–S209–S242A pyrin.fl triple mutant or wild‐type pyrin.fl in the presence of an inhibitor of 14.3.3–ligand interactions was used, promotion of nuclear translocation of pyrin was observed.

Conclusion

These results disclose the role played by 14.3.3 in the regulation of the subcellular compartmentalization of pyrin in a phosphorylation‐ and isoform‐dependent manner. They also reconcile the observations made in vitro with those made in vivo, while providing a direct link between 14.3.3‐dependent pathways and pyrin.
Nonsteroidal antiinflammatory drugs reduce radiographic progression in patients with ankylosing spondylitis: A randomized clinical trial
Authors: Wanders Astrid , Heijde Désirée van der , Landewé Robert , Béhier Jéhan‐Michel , Calin Andrei , Olivieri Ignazio , Zeidler Henning , Dougados Maxime
Published: June 2005

Objective

A 2‐year randomized controlled trial was performed to test the hypothesis that long‐term, continuous treatment with nonsteroidal antiinflammatory drugs (NSAIDs), in comparison with NSAID treatment on demand only, influences radiographic progression in patients with ankylosing spondylitis (AS).

Methods

Patients with AS (n = 215), who had previously participated in a 6‐week, randomized, double‐blind clinical trial that compared celecoxib, ketoprofen, and placebo, were randomly allocated to receive either continuous treatment with NSAIDs or on‐demand treatment with NSAIDs for a period of 2 years. All patients began treatment with celecoxib, at a starting dosage of 100 mg twice daily; patients could increase this dosage to 200 mg twice daily or could switch to another NSAID while maintaining the same treatment strategy. Structural changes were assessed by radiographs of the lumbar and cervical spine and scored according to the modified Stoke Ankylosing Spondylitis Spine Score by one observer who was blinded to the treatment strategy and temporal order of the radiographs. Statistical analyses included a between‐group comparison of 1) radiographic progression scores (by Mann‐Whitney U test), 2) time‐averaged values of variables reflecting signs and symptoms of AS (by linear regression analysis), and 3) the frequency of reported site‐specific adverse events (by chi‐square test or Fisher's exact test, as appropriate).

Results

Complete sets of radiographs were available for 76 of the 111 patients in the continuous‐treatment group and for 74 of the 104 patients in the on‐demand group. The mean ± SD scores for radiographic progression were 0.4 ± 1.7 in the continuous‐treatment group and 1.5 ± 2.5 in the on‐demand treatment group (P = 0.002). Parameters reflecting signs and symptoms were not statistically significantly different between groups. The between‐group difference in radiographic progression did not disappear after adjusting for baseline values of radiographic damage or disease activity variables and for time‐averaged values of disease activity variables, nor after imputation of missing data. Relevant adverse events tended to occur more frequently in the continuous‐treatment group than in the on‐demand group (for hypertension, 9% versus 3%; for abdominal pain, 11% versus 6%; for dyspepsia, 41% versus 38%), but the differences were not statistically significant.

Conclusion

A strategy of continuous use of NSAIDs reduces radiographic progression in symptomatic patients with AS, without increasing toxicity substantially.
The involvement of Vα14 natural killer T cells in the pathogenesis of arthritis in murine models
Authors: Chiba Asako , Kaieda Shinjiro , Oki Shinji , Yamamura Takashi , Miyake Sachiko
Published: June 2005

Objective

To examine the physiologic role of natural killer T (NKT) cells bearing Vα14 T cell receptor (TCR) in the pathogenesis of collagen‐induced arthritis (CIA) and antibody‐induced arthritis in mice.

Methods

NKT cells were stained with α‐galactosylceramide–loaded CD1 dimer, and then assessed using flow cytometry. CIA was induced in mice by immunization on days 0 and 21 with type II collagen (CII) emulsified with an equal volume of Freund's complete adjuvant. Anti‐CII antibodies were measured by enzyme‐linked immunosorbent assay. For antibody‐induced arthritis, mice were injected with anti‐CII monoclonal antibodies (mAb) followed by lipopolysaccharide, or with serum from KRN TCR–transgenic mice crossed with nonobese diabetic mice (K/BxN). The severity of arthritis was monitored with a macroscopic scoring system.

Results

The number of NKT cells increased in the liver at the peak of the clinical course of CIA. Administration of anti‐CD1 mAb inhibited development of CIA. The severity of CIA in NKT cell–deficient mice was reduced compared with that in wild‐type mice. The IgG1:IgG2a ratio of anti‐CII was elevated and production of interleukin‐10 from draining lymph node cells was increased in NKT cell–deficient mice. NKT cell–deficient mice were significantly less susceptible to antibody‐induced arthritis.

Conclusion

NKT cells contribute to the pathogenesis of arthritis by enhancing autoantibody‐mediated inflammation. NKT cells also contribute to the disease process in a deleterious way, due, at least in part, to the alteration of the Th1/Th2 balance in T cell response to CII.
Whole‐genome screening for susceptibility genes in multicase families with Behçet's disease
Authors: Karasneh Jumana , Gül Ahmet , Ollier William E. , Silman Alan J. , Worthington Jane
Published: June 2005

Objective

Behçet's disease is generally considered to be a multifactorial disease with important genetic and environmental components. A strong association between an HLA class I antigen, HLA–B51, and Behçet's disease has long been known. However, analysis of multicase families has suggested a substantial contribution of non‐HLA loci. The aim of this study was to perform a whole‐genome linkage analysis for identification of other susceptibility loci for Behçet's disease in multicase families.

Methods

The study group comprised a total of 193 individuals (90 male, 103 female) from 28 multicase families of Turkish origin; 83 of the subjects (50 males, 33 females) fulfilled the International Study Group criteria for Behçet's disease. Three hundred ninety‐five highly informative microsatellite markers spanning the genome were genotyped using fluorescent polymerase chain reaction primers and a fully automated electrophoresis platform. After the first analysis, 33 additional markers that were located close to the peak linkage areas were genotyped in all individuals. Nonparametric multipoint linkage analysis was carried out using GeneHunter version 2.1 software.

Results

Evidence for linkage (P ≤ 0.05) was obtained in 16 chromosome regions: 1p36, 4p15, 5q12, 5q23, 6p22–24, 6q16, 6q25–26, 7p21, 10q24, 12p12–13, 12q13, 16q12, 16q21–23, 17p13, 20q12–13, and Xq26–28. After the addition of further markers, the maximum nonparametric linkage score increased from 3.5 to 3.94 at 12p12–13 (D12S77; P = 0.0002) and from 3.07 to 3.70 at 6p22–24 (D6S285; P = 0.0005).

Conclusion

This study is the first systematic genome screen in Behçet's disease and provides evidence of linkage to several non‐HLA susceptibility loci in a cohort of Turkish multicase families. This represents the first step toward the identification of novel Behçet's disease susceptibility genes.
Rapid responses to anakinra in patients with refractory adult‐onset Still's disease
Authors: Fitzgerald Avril A. , LeClercq Sharon A. , Yan Alexander , Homik Joanne E. , Dinarello Charles A.
Published: June 2005

Objective

To assess the efficacy of anakinra treatment in patients with adult‐onset Still's disease (AOSD) that is refractory to corticosteroids, methotrexate (MTX), and etanercept.

Methods

Four patients with AOSD were treated with prednisone and MTX and 2 patients were also treated with etanercept for worsening symptoms and indicators of systemic inflammation. White blood cells (WBCs), C‐reactive protein (CRP) levels and/or erythrocyte sedimentation rate, and ferritin levels were measured and, in 1 patient, serum creatinine levels were determined. Treatment with anakinra at 100 mg/day was initiated.

Results

The index patient's disease was refractory to treatment with prednisone (30 mg/day) and MTX, with spiking fevers, rash, synovitis, a serum ferritin level of 8,400 ng/ml (normal ≤200), and a CRP level of 86 mg/liter (normal <8). Levels of interleukin‐1β (IL‐1β), IL‐1α, IL‐6, IL‐1 receptor antagonist, and IL‐18 were elevated. Just prior to anakinra treatment, the WBC count was 14,600/mm3, the CRP level was 86 mg/liter, and the ferritin level was 573 ng/ml, with daily spiking fevers to 104°F, rash, and swollen joints. Within hours of the first injection, the patient was afebrile and asymptomatic; within days, the WBC count, ferritin level, and CRP level decreased into the normal range. On 2 occasions, anakinra was withheld. Within a few days, the WBC count rose to >20,000/mm3with prominent neutrophilia, the CRP level rose to >200 mg/liter, and the ferritin level rose to >3,000 ng/ml. Upon restarting anakinra, the patient became afebrile, the WBC count fell to 8,000/mm3, the CRP level fell to <3 mg/liter, and the ferritin level fell to <300 ng/ml. Three additional patients with refractory AOSD who experienced rapid reductions in fever, symptoms, and markers of inflammation when treated with anakinra are reported.

Conclusion

Refractory AOSD appears to be IL‐1–mediated since anakinra decreases hematologic, biochemical, and cytokine markers and also produces rapid reductions in systemic and local inflammation. Reported efficacy of tumor necrosis factor–blocking therapies in AOSD may be due to a reduction in IL‐1.
Human β‐defensin 3 mediates tissue remodeling processes in articular cartilage by increasing levels of metalloproteinases and reducing levels of their endogenous inhibitors
Authors: Varoga Deike , Pufe Thomas , Harder Jürgen , Schröder Jens‐Michael , Mentlein Rolf , Meyer‐Hoffert Ulf , Goldring Mary B. , Tillmann Bernhard , Hassenpflug Joachim , Paulsen Friedrich
Published: June 2005

Objective

Beta‐defensins are broad‐spectrum antimicrobial peptides (APs) that are components of innate immunity. Recent investigations showed the induction of β‐defensins in synovial membranes of osteoarthritic (OA) joints and suggested that they have functions other than the ability to kill microbes. As a result of these findings, we undertook this study to investigate the production of human β‐defensin 3 (HBD‐3) in OA cartilage and to determine its influence on chondrocyte function.

Methods

Healthy and OA cartilage were assessed for HBD‐3 expression by reverse transcriptase–polymerase chain reaction (RT‐PCR) and immunohistochemistry. HBD‐3 expression in C28/I2 chondrocytes after administration of tumor necrosis factor α (TNFα) and interleukin‐1 (IL‐1) was determined by real‐time RT‐PCR and immunodot blot. Enzyme‐linked immunosorbent assay experiments were used to study the effects of HBD‐3 in cultured articular chondrocytes and in healthy and OA cartilage discs. Immunohistochemical analyses were performed to study the expression of mouse β‐defensins (MBDs) in OA cartilage of STR/Ort mice.

Results

HBD‐3 was induced in OA cartilage without bacterial challenge. Cytokines involved in the pathogenesis of OA, namely, TNFα and IL‐1, were strong inducers of HBD‐3 in cultured chondrocytes. Application of the recombinant HBD‐3 protein to cultured chondrocytes and cartilage discs resulted in increased production of cartilage‐degrading matrix metalloproteinases and in down‐regulation of their endogenous regulators, tissue inhibitors of metalloproteinases 1 and 2. Furthermore, STR/Ort mice, which are genetically predisposed to develop OA‐like lesions in the knee joint, demonstrated an increased expression of MBDs 3 and 4 in cartilage compared with that in healthy animals.

Conclusion

These findings widen our knowledge of the functional spectrum of APs and demonstrate that HBD‐3 is a multifunctional AP with the ability to link host defense mechanisms and inflammation with tissue‐remodeling processes in articular cartilage. Moreover, our data suggest that HBD‐3 is an additional factor in the pathogenesis of OA.
Class II major histocompatibility complex–peptide tetramer staining in relation to functional avidity and T cell receptor diversity in the mouse CD4+ T cell response to a rheumatoid arthritis–associated antigen
Authors: Falta Michael T. , Fontenot Andrew P. , Rosloniec Edward F. , Crawford Frances , Roark Christina L. , Bill Jerome , Marrack Philippa , Kappler John , Kotzin Brian L.
Published: June 2005

Objective

Although studies have suggested that human cartilage (HC) gp‐39 may be an antigen recognized by autoreactive CD4+ T cells in rheumatoid arthritis, we previously failed to identify specific CD4+ T cells in patients' synovial fluid or blood using a class II major histocompatibility complex–peptide tetramer composed of the immunodominant HC gp‐39263–275 epitope covalently linked to DR4. We undertook this study to better understand the parameters for specific binding of this tetramer.

Methods

DR4‐transgenic mice were immunized with the HC gp‐39 peptide, and a set of peptide‐responsive hybridomas was derived. Hybridomas were stained with the DR4–gp‐39 tetramer and cultured with increasing amounts of peptide in the presence of DR4‐expressing antigen‐presenting cells to determine functional avidity.

Results

Great variability was apparent in the ability of the tetramer to stain the hybridomas, and there was a strong correlation between the intensity of tetramer staining and functional avidity. Importantly, nearly 30% of the hybridomas did not stain with tetramer, and these cells exhibited relatively low functional avidity. Although the addition of an anti–T cell receptor (anti‐TCR) monoclonal antibody during the staining procedure enhanced binding of the tetramer to a number of the hybridomas, a significant percentage remained unstainable. Analysis of TCR expression showed that >90% of the hybridomas expressed the same TCR β‐chain variable region (Vβ10), and sequencing of the TCR junctional regions showed diversity in the third complementarity‐determining region.

Conclusion

These results suggest that immune responses dominated by relatively low‐affinity TCR interactions, such as those that may occur in autoimmune disease, will be difficult to detect using standard tetramer techniques.
Interleukin‐4 can be a key positive regulator of inflammatory arthritis
Authors: Ohmura Koichiro , Nguyen Linh T. , Locksley Richard M. , Mathis Diane , Benoist Christophe
Published: June 2005

Objective

Development of arthritis in the K/BxN mouse model depends on the induction of high titers of antibodies against the enzyme glucose‐6‐phosphate isomerase (GPI), promoted by CD4+ T cells expressing a GPI‐specific transgenic T cell receptor (TCR). This study was undertaken to determine whether this strong autoantibody response depends on T cell differentiation to the Th1 or Th2 phenotype.

Methods

The roles of Th cell–biasing cytokines were investigated by introducing the interleukin‐4 (IL‐4) and IL‐12–specific subunit p35 (IL‐12p35)–knockout mutations into the K/BxN model and evaluating the impact of these deficiencies on disease. The IL‐4–expressing cell types in K/BxN mice were revealed by crossing in a knockin alteration, which resulted in green fluorescent protein expression controlled by endogenous IL‐4 gene–regulatory elements. Transfer experiments permitted the identification of the IL‐4–producing cell type required for arthritis, and quantitative reverse transcriptase–polymerase chain reaction allowed for determination of the cytokine profile of K/BxN T cells.

Results

While IL‐12p35 appeared dispensable for the development of arthritis, IL‐4 was crucial for full development of disease. The GPI‐reactive TCR of standard K/BxN mice induced the transcriptional activation of the IL‐4 locus in CD4+ T cells and eosinophils, and CD4+ T cells were the obligatory source of IL‐4 for disease. However, the cytokine profile of K/BxN T cells revealed that K/BxN arthritis is not a “pure” Th2 disease.

Conclusion

The K/BxN model, although not a classic Th2 disease, depends critically on IL‐4. The potential of IL‐4 to promote inflammatory arthritis should be considered when proposing therapies for rheumatoid arthritis aimed at biasing T cells toward IL‐4 production.