bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and gelation of fluoroalkyl end‐capped copolymers containing glucosyl segments: Application to new fluorinated conductive polymer electrolytes
Authors: Sawada Hideo , Murai Yuka , Kawase Tokuzo , Minami Toshiyuki , Kyokane Jun
Published: October 2002

Fluoroalkyl end‐capped copolymers containing glucosyl segments were prepared by the copolymerizations of fluoroalkanoyl peroxides with 2‐glucosyoxyethyl methacrylate (GEMA) and comonomers such as acrylic acid (ACA) and methacrylate monomer‐containing poly(oxyethylene) units (PME). Under the non‐cross‐linked conditions, fluoroalkyl end‐capped GEMA–ACA and GEMA–PME copolymers were found to cause a gelation in dimethyl sulfoxide (DMSO), where the aggregations of end‐capped fluoroalkyl segments and the hydrogen‐bonding interaction between hydroxyl segments are involved in establishing a physical gel network, although the corresponding nonfluorinated GEMA copolymers could cause no gelation in DMSO. More interestingly, it was demonstrated that these fluorinated polymeric gelling electrolytes containing lithium salts exhibit a considerably high ionic conductivity of 10−3 S/cm level at room temperature. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2833–2838, 2002
Reinforcement of natural rubber
Authors: Bokobza Liliane , Rapoport Olivier
Published: October 2002

In this article, we report on recent investigations on filled natural rubber. These investigations include a mechanical characterization as well as a molecular analysis based on measurements of chain orientation. It is demonstrated that at intermediate strains, the increase in the moduli can be explained by the inclusion of rigid particles in the soft matrix and from molecular interactions between the rubber and the filler. These interactions can be evaluated by equilibrium swelling and by orientational measurements. With regard to the unfilled formulation, carbon black– and silanized‐filled natural rubber exhibit increases in the cross‐linking density ascribed to filler‐polymer links, whereas a large decrease in the orientational level, evidenced by birefringence and by infrared dichroism, is observed when silica is added without any coupling agent. Finally, two specific effects—the Payne and Mullins effects, both related to energy dissipation phenomena—are discussed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2301–2316, 2002
Studies on the synthesis and optical properties of novel blue light‐emitting polymers containing phosphorus and oxadiazole structures
Authors: Sun Yih‐Min , Hung Albert Y. C. , Wang Chih‐Ta
Published: October 2002

Novel phosphorus‐containing polymers with high‐electron‐affinity oxadiazole were synthesized and characterized by thermal analysis and spectroscopy (infrared, ultraviolet‐visible, photoluminescence, cyclic voltammetry) measurements. These new polymers can be used as blue electroluminescent materials and as electron‐transport layers in polymer light‐emitting diodes. In this study, aromatic polyethers containing electron‐transporting chromophores and emission chromophores were synthesized from 2,5‐bis‐(4‐fluoroaryl)‐1,3,4‐oxadiazole and 2‐(6‐oxido‐6H‐dibenz<1,2> oxaphosphorin‐6‐yl)‐1,4‐naphthalenediol (DOPO‐NBQ). The effects of reaction temperature and time on the formation of polyethers were investigated to obtain optimum conditions for polyether manufacturing. All the resulting polymers were thermally stable at <460 °C. The absorption peaks of these polymers were at 350–365 nm, whereas the photoluminescent peaks were at 460–481 nm. But, the intensity of polymer absorption decreased and a blue shift was observed in the photoluminescent spectra as the temperature increased. In addition, these polymers containing the electron‐transporting oxadiazole indeed showed extra reduction potentials in cyclic voltammetry measurements. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2367–2376, 2002
Studies on hyperbranched polyurethane by multidetector size exclusion chromatography
Authors: Hong Ling , Wang Xinling , Tang Xiaozhen
Published: October 2002

Hyperbranched polyurethane (HP) and its linear analog (LPU) were studied by size exclusion chromatography (SEC), utilizing a combination of refractive index (RI), right angle light scattering (RALLS), and differential viscosity (DV) detectors. The relationships between retention volume (Ve), intrinsic viscosity (η), radius of gyration (Rg), and the molecular structure were investigated. It was shown that the hyperbranched polyurethane had lower Ve, η, and Rg than its linear analog when they had the same molecular weight. The branching parameter g and g′ were calculated. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2445–2450, 2002
The properties of epoxy–imide resin cured by phosphorylated diamines containing different alkyl groups on phosphorus
Authors: Yeh Ching‐Fen , Wang Tsui‐Shuang , Cherng Jong‐Yuh , Kuo Jung‐Hua Steven , Shau Min‐Da
Published: October 2002

Cured networks of epoxy–imide resin cured with four types of phosphorylated diamine curing agents that contained different alkyl groups on phosphorus were studied. The structures of these novel phosphorus‐containing curing agents were confirmed by Mass, EA, IR, and 1H‐NMR and 13C‐NMR spectra characterization. The reactivities were measured by differential scanning calorimetry (DSC). It is found that the reactivities were not affected by the types of alkyl groups in the curing agents. In thermal gravimetric analysis (TGA), those polymers that were obtained through the curing reactions between epoxy–imide resin and four curing agents (BAMP, BAEP, BAPP, and BABP) also demonstrated excellent thermal properties as well as a high char yield. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 141–147, 2002
A structural–thermodynamic study of triphenylsilylcellulose
Authors: Bontea D.
Published: October 2002

The purpose of this article is to report the characterization of a solution of triphenylsilylcellulose (TPSC) in terms of its rheologic properties by osmometry and viscometry to better understand processing parameters and conditions. This work is an extension of previous similar work on trimethylsilylcellulose (TMSC). TPSC was prepared in a medium of dimethylformamide (DMF) plus pyridine, under heterogeneous starting conditions and nitrogen atmosphere, by silylation of activated celluloses with triphenylchlorosilane at 115–120 °C. The isolated and purified ethers were characterized according to their polydispersities and their substitution degrees, by osmometry and viscometry in various solvents. The Mark–Houwink–Sakurada equation coefficients were evaluated in 1,1,1‐trichloroethane, chloroform, and o‐xylene at 30 °C and in o‐xylene over the 30–70 °C temperature range. The values of 2.12–2.18 obtained for exponent “a” correlated with the very low values of pre‐exponential factor (of 10−12 order), indicating a high stiffness of the macromolecular chains. The viscous flow parameters for dilute solutions of TPSC in o‐xylene were determined in the temperature range 30–70 °C. The temperature dependence of the dynamic viscosity of the solutions obeys an Arrhenius‐type equation in which the apparent activation energy is linearly dependent on both the concentration and molecular weight of the solution. No significant dependence on concentration and molecular weight was found for the pre‐exponential factor. This behavior was attributed to the great stiffness of the macromolecular chains. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2875–2884, 2002
Preparation of epoxy blends with nanoparticles by acoustic levitation technique
Authors: Cao Youming , Xie Wenjun , Sun Jun , Wei Bingbo , Lin Shang'an
Published: October 2002

Three types of blends consisting of nano‐Al2O3 particles, polyester, and epoxy resin were respectively prepared as suspended small balls in an acoustical levitator with a microgravity state. The microstructures of the blends were compared to those with identical composition prepared in a normal gravity field. The results showed that the nanoparticles was deposited at the bottom of blends, and the polyester possessed a sphere‐crystalline‐dispersed phase when the blends were prepared in the normal gravity field. However, the nanoparticles can be dispersed into epoxy resin at a nanoscale, and the polyester transformed to a highly dispersed amorphous phase when the blends were prepared by the acoustic levitation technique. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 84–89, 2002
Crystallization kinetics and crystalline morphology of poly(ethylene naphthalate) and poly(ethylene terephthalate‐co‐bibenzoate)
Authors: Hu Y. S. , Rogunova M. , Schiraldi D. A. , Hiltner A. , Baer E.
Published: October 2002

Copolymers of ethylene glycol with 4,4′‐bibenzoic acid and terephthalic acid are known to crystallize rapidly to surprisingly high levels of crystallinity. To understand this unusual behavior, the isothermal crystallization of poly(ethylene bibenzoate‐co‐terephthalate) in the molar ratio 55:45 (PETBB55) was studied. Poly(ethylene naphthalate) (PEN) was included in the study for comparison. The kinetics of isothermal crystallization from the melt and from the amorphous glass was determined using differential thermal analysis. The results were correlated with the crystalline morphology as observed with atomic force microscopy (AFM). Crystallization of PEN exhibited similar kinetics and spherulitic morphology regardless of whether it was cooled from the melt or heated from the glass to the crystallization temperature. The Avrami coefficient was close to 3 for heterogeneous nucleation with 3‐dimensional crystal growth. The copolymer PETBB55 crystallized much faster than did PEN and demonstrated different crystallization habits from the melt and from the glass. From the melt, PETBB55 crystallized in the “normal” way with spherulitic growth and an Avrami coefficient of 3. However, crystallization from the glass produced a granular crystalline morphology with an Avrami coefficient of 2. A quasi‐ordered melt state, close to liquid crystalline but lacking the order of a recognizable mesophase, was proposed to explain the unusual crystallization characteristics of PETBB55. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 98–115, 2002
High‐resolution solid‐state NMR and SEM study of the interaction behavior of poly(ethylene‐co‐vinyl acetate)/poly(vinyl acetate) blends
Authors: De Souza Cláudia M. G. , Tavares Maria Inês B.
Published: October 2002

Binary blends formed by two types of ethylene‐co‐vinyl acetate (EVA), which have different vinyl acetate contents, and poly(vinyl acetate) (PVAc) were prepared in a Haake Rheocord 9000 plastograph. A series of samples were obtained varying the PVAc amount up to 50%. The studies were carried out employing solid‐state nuclear magnetic resonance spectroscopy (NMR) and scanning electronic microscopy (SEM). The xenon‐129 (129Xe) and carbon‐13 (13C) NMR response together with the microscopy results showed that the systems are heterogeneous. Therefore, EVA with a higher vinyl acetate content presented some interaction between the polymer blend components. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 116–124, 2002
Preparation and characterization of nickel–polystyrene nanocomposite by ultrasound irradiation
Authors: Kumar R. Vijaya , Koltypin Yu. , Palchik O. , Gedanken A.
Published: October 2002

Well‐dispersed nickel nanoparticles in polystyrene were obtained by a sonochemical method. The properties of the as‐prepared nanocomposite materials were characterized by XRD, TEM, EDAX, TGA, DSC, and a vibrating sample magnetometer (VSM). The nickel particles were 5 nm in diameter and were very well dispersed in the polystyrene. The magnetization measurements established that the as‐prepared nanocomposite materials are superparamagnetic due to their small size. The saturation magnetization (30.1 emu/g) and coercivity (5 Oe) of the materials were significantly smaller than were those of the bulk nickel, reflecting the nanoparticle nature. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 160–165, 2002
Characterization by thermal analysis of high density polyethylene/polypropylene blends with enhanced biodegradability
Authors: Contat‐Rodrigo L. , Ribes‐Greus A. , Imrie C. T.
Published: October 2002

Blends of high density polyethylene (HDPE) and polypropylene (PP) with different biodegradable additives have been subjected to an outdoor soil burial test. The effect of the degradation process on the structural and morphological properties of the samples has been studied by thermogravimetry, differential scanning calorimetry, and dynamic‐mechanical spectroscopy. The thermogravimetric results show that the additive is more affected by the degradation process than the polymeric matrix. Changes both in the crystalline morphology and the activation energies of the relaxation processes take place in different stages, and can be described using polynomial equations. These changes occur on different time scales depending on the additive used. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 174–185, 2002
The external electric field effects on the morphology of phase separation in a mixture of liquid crystal/flexible polymer
Authors: Hong Ke , Zhang Hongdong , Yang Yuliang
Published: October 2002

In this article, the morphologies of phase separation in the mixtures of small molecular liquid crystal and flexible polymers with or without being subjected to the external electric field are preliminarily studied by polarized light microscope. It is found that the characteristic “Swiss cheese” morphology can always be observed for the case of zero field strength. For the case of 1.2 V/μm field strength, it is found that the external electric field make the binodal curves of the phase diagrams shift to higher temperature and the “Swiss cheese” morphology can never be observed. However, the domain growth rate is highly accelerated due to the fact that the electric field oriented liquid crystal phase excludes the polymer coils strongly. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 250–258, 2002
Transition metal‐catalyzed atom transfer radical polymerization of stearyl methacrylate in the presence of carbon tetrabromide and a conventional radical initiator
Authors: Saikia Prakash J. , Goswami Aradhana , Baruah Shashi D.
Published: October 2002

Atom transfer radical polymerization of stearyl methacrylate (SMA) was successfully carried out in N,N‐dimethylformamide using the carbon tetrabromide/Fe(III)/2,2′‐bipyridine initiator system in the presence of 2,2′‐azobisisobutyronitrile (AIBN) as the source of the reducing agent to maintain the equilibrium between growing radicals and dormant species. The molecular weights of the resulting poly(stearyl methacrylate) (PSMA) increased with the conversion and the molecular weight distribution of PSMA was quite narrow. The rates of polymerization exhibit first‐order kinetics with respect to the monomer. A probable reaction mechanism for the polymerization system was postulated to explain the observed results. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 386–394, 2002
Effect of the octadecyl acrylate concentration on the phase behavior of poly(octadecyl acrylate)/supercritical CO2 and C2H4 at high pressures
Authors: Byun Hun‐Soo , Choi Tae‐Hyun
Published: October 2002

Pressure–composition isotherms were measured for the CO2/octadecyl acrylate system at 45.0, 80.0, and 100.0°C and at pressures up to 307 bar. This system exhibited type I phase behavior with a continuous mixture‐critical curve. The solubility of octadecyl acrylate for the CO2/octadecyl acrylate system increased as the temperature increased at a constant pressure. The experimental results for the CO2/octadecyl acrylate system were modeled with the Peng–Robinson equation of state. A good fit of the data was obtained with the Peng–Robinson equation of state with one adjustable parameter for the CO2/octadecyl acrylate system. Experimental cloud‐point data for the poly(octadecyl acrylate)/CO2/octadecyl acrylate system were measured from 36 to 193°C and at pressures up to 2100 bar, and the added octadecyl acrylate concentrations were 11.9, 25.9, 28.0, 35.0, and 40.0 wt %. Poly(octadecyl acrylate) dissolved in pure CO2 up to 250°C and 2100 bar. Also, adding 45.0 wt % octadecyl acrylate to the poly(octadecyl acrylate)/CO2 solution significantly changed the phase behavior. This system changed the pressure–temperature slope of the phase‐behavior curves from an upper critical solution temperature (UCST) region to a lower critical solution temperature region as the octadecyl acrylate concentration increased. Cloud‐point data to 150°C and 750 bar were examined for poly(octadecyl acrylate)/C2H4/octadecyl acrylate mixtures at octadecyl acrylate concentrations of 0.0, 15.0, and 45.0 wt %. The cloud‐point curve of the poly(octadecyl acrylate)/C2H4 system was relatively flat at 730 bar between 41 and 150°C. The cloud‐point curves of 15.0 and 45.0 wt % octadecyl acrylate exhibited positive slopes extending to 35°C and approximately 180 bar. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 372–380, 2002
Transcrystallinity effects in high‐density polyethylene. I. Experimental observations in differential scanning calorimetry analysis
Authors: Billon N. , Henaff V. , Pelous E. , Haudin J. M.
Published: October 2002

The crystallization of a high‐density polyethylene was analyzed with differential scanning calorimetry (DSC) measurements. An intense transcrystallinity was observed at the contact between the polymer and the DSC pans. The modification of the crystallization kinetics induced by this phenomenon was studied as a function of cooling rate and sample thickness. We point out that most of the theoretical predictions of our previous model could be checked. The crystallization temperature was a function of the sample thickness and could be also correlated with the thickness of the transcrystalline zones. The shapes of the DSC traces were complex and correlated with the amount of trancrystallization. The usual interpretations of such DSC curves were not accurate. We conclude that specific experimental procedures must be proposed to understand and correctly use such measurements. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 725–733, 2002
Polymer‐based catalysts for toluene hydrogenation
Authors: Reyes Patricio , Borda Gloria , Rivas Bernabé L. , Cárdenas Galo
Published: October 2002

Crosslinked poly(4‐vinylpyridine‐co‐styrene) was synthesized by radical polymerization. Catalysts having 1 wt % Pd were obtained by impregnation of a copolymer, poly(4‐vinylpyridine‐co‐styrene) with a Pd colloidal dispersion. We modified metal particle sizes by changing the aging period of the colloidal dispersion, with the average size in the range of 2.5–4.3 nm. The most probable structure of the metal cluster attached to the polymers is described. X‐ray diffraction, transmission electron microscopy (TEM), and H2O2 titrations were used as characterization techniques. The H2 consumption during titration was extremely low, and the calculated metal dispersion was between 15 and 25 times lower than those estimated from TEM. This suggests that the Pd crystals were almost completely covered by the polymer. The vapor‐phase hydrogenation of toluene on resins supported Pd catalysts were studied. The catalysts in the hydrogenation of toluene exhibited low activity, and the obtention of significant selectivities to partial hydrogenation products (close to 60 mol %) was remarkable. The results are explained in terms of a significant decrease in the hydrogenation capacity due to the coverage of metal particles by the resin. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 381–385, 2002
Interpolymer associations between poly(vinyl alcohol) and poly(diallyldimethylammonium chloride) in aqueous dilute solution
Authors: Ould M'Bareck Chamekh , Metayer Michel , Labbe Michel
Published: October 2002

This article studied the compatibility of poly(vinyl alcohol) (PVA) with poly(diallyldimethylammonium chloride) (PDADMACl) in a dilute aqueous solution. At a total mixture concentration and a constant molecular weight of PDADMACl, it was found that interpolymer associations increase with the molecular weight and decrease with the degree of hydrolysis of the PVA sample (87–89 and 98–99%). From these results, it can be deduced that the compatibility of PVA and PDADMACl is due to specific intermolecular interactions that could be assigned mainly to electrostatic interactions between hydroxyl groups within PVA chains and ion atoms within PDADMACl. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 433–435, 2002
NMR spectroscopic studies of dimethyldiethoxy silane hydrolysis and polysiloxane conversion
Authors: Tsai Ming‐Fu , Lee Yu‐Der , Chen Kan‐Nan
Published: October 2002

The hydrolysis rate of alkoxy silane (dimethyldiethoxy silane, DMDES, etc.) is a linear relationship vs. the reaction time under the moisture flux control. The hydrolysis process results in formation of the linear polysiloxane products by a subsequent condensation reaction. An amidized alkoxy silane (3‐(2‐aminoethyl)aminopropylmethyldimethoxy silane, KLM‐602 or γ–aminopropyl‐ triethoxy silane, γ–APS) serves as an internal standard of DMDES hydrolysis kinetics measurements. The hydrolysis kinetics of DMDES with the amidized alkoxy silane and the subsequent linear polysiloxanes conversion have been evaluated and characterized by 29Si‐ and 13C‐NMR NMR spectroscopic measurements. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 468–477, 2002
A study of solvent exchange process in (ethylene–vinyl alcohol) copolymer gels by a proton nuclear magnetic resonance spectroscopy imaging method
Authors: Kanekiyo Masahito , Kobayashi Masatoshi , Ando Isao , Kurosu Hiromichi , Amiya Shigetoshi
Published: October 2002

The proton nuclear magnetic resonance (1H NMR) image patterns of (ethylene–vinyl alcohol) copolymer (EVOH)/dimethylsulfoxide (DMSO) gels with various ethylene contents were measured to elucidate the process of solvent exchange between DMSO and water in the gels soaked in water. The results of these experiments indicate that the rate of solvent exchange between DMSO and water in the gels increased with an increase in the ethylene content of EVOH copolymers. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 504–508, 2002
Novel chemical methods for the infiltration of opal particles with electrically conductive polyaniline polymers
Authors: Khalil Hanaa S. A. , Levon Kalle
Published: October 2002

Chemical methods for successfully coating opal particles with electrically conducting polyaniline (PANi) polymers were studied. Two different routes were proven successful. First was the in situ chemical doping reaction of PANi with dodecylbenzenesulfonic acid (DBSA) and camphorsulfonic acid dopants. The other method was placement of opal particles in a low concentration of a conducting PANi/DBSA solution in chloroform. Ultraviolet analyses of opal samples showed typical spectra for doped PANi with delocalized polarons. The electrical resistance of coated opal was measured to be 0.75 × 103 Ω. Morphological studies of the fractured surface by scanning electron microscopy indicated successful coating. Cyclic voltammetry studies confirmed the percolating behavior of infiltrated PANi. Also, a selective electroactive behavior toward the type of dopant was observed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 788–793, 2002
Survey of fibroblast growth factor expression during chick organogenesis
Authors: Karabagli Hakan , Karabagli Pinar , Ladher Raj K. , Schoenwolf Gary C.
Published: October 2002

Members of the extensive fibroblast growth factor (FGF) family play many key roles during embryonic development. In later development, during the course of organogenesis, these factors have been shown to direct distinct cellular pathways within the context of a particular organ system. To gain more insight into the processes that these factors may be controlling, we conducted a survey of the expression of known FGF family members in chick embryos at stages 18–25. We show the expression patterns of fgf‐2, ‐3, ‐4, ‐8, ‐10, ‐12, ‐13, ‐14, and ‐18 in the head, trunk, limbs, heart, and tail of the embryo. Anat Rec 268:1–6, 2002. © 2002 Wiley‐Liss, Inc.
Characterisation of aphid myrosinase and degradation studies of glucosinolates
Authors: Francis Frédéric , Lognay Georges , Wathelet Jean‐Paul , Haubruge Eric
Published: October 2002

Myrosinase from Brevicoryne brassicae was purified by ammonium sulfate fractionation, dialysis, and chromatography on a DEAE column. The chromatography yielded a single peak and a 115.6‐fold purification. Further FPLC gel filtration gave a single peak at 120 kDa. Denaturing SDS/PAGE of the protein revealed a single band at 60 kDa, indicating that the native B. brassicae myrosinase is a dimer. Kinetic parameters towards 8 glucosinolates were calculated. Strong differences of Vmax and Km were observed depending on the substrate. Degradation products of each glucosinolate were identified and quantified by GC‐MS and GLC‐FID, respectively. Using both crude aphid homogenates and purified myrosinase, two unique hydroxyglucosinolates, 3‐butenyl‐ and benzyl‐isothiocyanates were identified from progoitrin ((2S)‐2‐hydroxybut‐3‐enyl‐glucosinolate) and sinalbin (4‐hydroxybenzyl‐glucosinolate) degradation respectively. Addition of ascorbic acid to the reaction mixtures containing sinalbin and progoitrin caused the production of hydroxylated degradation products usually associated with plant myrosinase metabolisation. The occurrence of the myrosinase system in B. brassicae is discussed in terms of similar allelochemical adaptation between the herbivore and its host plant. Arch. Insect Biochem. Physiol. 50:173–182, 2002. © 2002 Wiley‐Liss, Inc.
Selective accumulation of CCR4+ T lymphocytes into renal tissue of patients with lupus nephritis
Authors: Yamada Masato , Yagita Hideo , Inoue Hideko , Takanashi Tsuyoshi , Matsuda Hironori , Munechika Eiko , Kanamaru Yutaka , Shirato Isao , Tomino Yasuhiko , Matushima Kouji , Okumura Ko , Hashimoto Hiroshi
Published: October 2002

Objective

Some chemokine receptors, such as CCR5 and CCR4, are differentially expressed on Th1 and Th2 cells. To determine whether differential expression of the chemokine receptors occurs in patients with lupus nephritis, we examined the expression of CCR4 and CCR5 on peripheral blood lymphocytes and mononuclear cells infiltrated into the renal tissue of patients with lupus nephritis.

Methods

The expression of CCR4 and CCR5 on CD4+,CD45RO+ cells was analyzed by flow cytometry and compared between patients with systemic lupus erythematosus (SLE) and healthy controls. Correlation between the absolute number of CCR4+ or CCR5+ cells and clinical parameters was also analyzed. Mononuclear infiltrates in the renal tissue of SLE patients were analyzed for the expression of CCR4, CCR5, and CD4 by immunohistochemical staining.

Results

The absolute number of CCR4+, but not CCR5+, T lymphocytes in the peripheral blood was significantly decreased in the patients with SLE compared with that in the healthy controls, and this positively correlated with the serum levels of C3 and CH50. Most of the CD4+ T lymphocytes that infiltrated into the renal tissue of the patients with lupus nephritis expressed CCR4, but not CCR5.

Conclusion

These results suggest that CCR4+ T lymphocytes in peripheral blood, which represent Th2 cells, preferentially migrate into the renal tissue of patients with lupus nephritis. The maldistribution of CCR4+ T lymphocytes might be involved in the pathogenesis of lupus nephritis.
Reduced chondrogenic and adipogenic activity of mesenchymal stem cells from patients with advanced osteoarthritis
Authors: Murphy J. Mary , Dixon Kenneth , Beck Stephen , Fabian Dennis , Feldman Andrew , Barry Frank
Published: October 2002

Objective

Mesenchymal stem cells (MSCs) are resident in the bone marrow throughout normal adult life and have the capacity to differentiate along a number of connective tissue pathways, among them bone, cartilage, and fat. To determine whether functionally normal MSC populations may be isolated from patients with advanced osteoarthritis (OA), we have compared cells from patients undergoing joint replacement with cells from normal donors. Cell populations were compared in terms of yield, proliferation, and capacity to differentiate.

Methods

MSCs were prepared from bone marrow aspirates obtained from the iliac crest or from the tibia/femur during joint surgery. In vitro chondrogenic activity was measured as glycosaminoglycan and type II collagen deposition in pellet cultures. Adipogenic activity was measured as the accumulation of Nile Red O‐positive lipid vacuoles, and osteogenic activity was measured as calcium deposition and by von Kossa staining.

Results

Patient‐derived MSCs formed colonies in primary culture that were characteristically spindle‐shaped with normal morphology. The primary cell yield in 36 of 38 cell cultures from OA donors fell within the range found in cultures from normal donors. However, the proliferative capacity of patient‐derived MSCs was significantly reduced. There was a significant reduction in in vitro chondrogenic and adipogenic activity in cultures of patient‐derived cells compared with that in normal cultures. There was no significant difference in in vitro osteogenic activity. There was no decline in chondrogenic potential with age in cells obtained from individuals with no evidence of OA.

Conclusion

These results raise the possibility that the increase in bone density and loss of cartilage that are characteristic of OA may result from changes in the differentiation profile of the progenitor cells that contribute to the homeostatic maintenance of these tissues.
The relationship of serum infliximab concentrations to clinical improvement in rheumatoid arthritis: Results from ATTRACT, a multicenter, randomized, double‐blind, placebo‐controlled trial
Authors: St.Clair E. William , Wagner Carrie L. , Fasanmade Adedigbo A. , Wang Benjamin , Schaible Thomas , Kavanaugh Arthur , Keystone Edward C.
Published: October 2002

Objective

To investigate the relationship between serum concentrations of infliximab, a monoclonal anti–tumor necrosis factor α antibody, and clinical improvement from infliximab therapy for rheumatoid arthritis (RA).

Methods

Multiple blood samples were obtained from each of 428 subjects with active RA who were enrolled in a multicenter, randomized, double‐blind, placebo‐controlled trial (ATTRACT [Anti–Tumor Necrosis Factor Trial in Rheumatoid Arthritis with Concomitant Therapy]) evaluating the clinical efficacy and safety of infliximab therapy. Serum levels of infliximab were measured by enzyme‐linked immunosorbent assay. Dose‐response trends were analyzed using generalized logistic regression techniques. Pharmacokinetic modeling was used to predict the serum concentrations of infliximab after simulated infusions using doses and dosing intervals not evaluated in the trial.

Results

At week 54, 26% of the subjects receiving 3 mg/kg infliximab every 8 weeks had undetectable trough serum levels of infliximab, a significantly greater proportion than in the other 3 treatment groups (P < 0.001). Increased magnitude of American College of Rheumatology (ACR) response (measured by the ACR‐N, a continuous measure of clinical improvement derived from the ACR 20% response criteria) and greater reduction from baseline in serum C‐reactive protein level were both associated with higher trough serum concentrations of infliximab (P < 0.001), as was less progression of radiographic joint damage (P = 0.004), providing support for a dose‐response relationship. Pharmacokinetic models predicted that decreasing the dosing interval from 8 weeks to 6 weeks would yield higher trough serum levels of infliximab than increasing the dose by 100 mg.

Conclusion

These results suggest that some patients with RA may benefit from infliximab given at higher doses than 3 mg/kg or more frequently than every 8 weeks.
Antifibroblast antibodies from systemic sclerosis patients are internalized by fibroblasts via a caveolin‐linked pathway
Authors: Ronda Nicoletta , Gatti Rita , Giacosa Roberto , Raschi Elena , Testoni Cinzia , Meroni Pier Luigi , Buzio Carlo , Orlandini Guido
Published: October 2002

Objective

Fibroblast activation is a crucial event in the development of systemic sclerosis (SSc). Antifibroblast autoantibodies (AFAs), detectable in the sera of SSc patients, are able to induce a proinflammatory phenotype on cultured fibroblasts. This study was undertaken to investigate the mechanisms of the interaction between AFAs and living fibroblasts.

Methods

We coupled to fluorescein 1) IgG purified from AFA‐positive and AFA‐negative SSc sera (as assessed by cellular enzyme‐linked immunosorbent assay) and 2) single healthy donor and pooled normal IgG. The interaction of IgG with living cultured fibroblasts from healthy individuals and from a patient with SSc was visualized by real‐time confocal microscopy. Intracellular colocalization of caveolin and internalized AFA‐positive IgG was assessed by immunofluorescence.

Results

AFA‐positive IgG bound to living fibroblasts and was internalized with a cytoplasmic fibrillar pattern, in contrast to AFA‐negative IgG. In the IgG tested, no correlation with antinuclear antibody activity was found. Preincubation of fibroblasts with normal IgG did not affect internalization. Internalized AFA‐positive IgG colocalized with caveolin, and internalization was entirely inhibited by disassembling fibroblast caveolae with filipin.

Conclusion

The finding that both normal and pathologic fibroblasts specifically internalized AFA‐positive, but not AFA‐negative, IgG demonstrates that AFAs in SSc patient sera interact with constitutively expressed membrane molecules on fibroblasts, via an Fc‐independent mechanism. The results of colocalization and inhibition experiments suggest that microdomains containing caveolin are involved in the interaction between AFAs and fibroblasts. These data, together with the reported ability of AFAs to activate fibroblasts, provide evidence for a role of AFAs in the pathogenesis of SSc.
C3‐Tat/HIV–regulated intraarticular human interleukin‐1 receptor antagonist gene therapy results in efficient inhibition of collagen‐induced arthritis superior to cytomegalovirus‐regulated expression of the same transgene
Authors: Bakker A. C. , van de Loo F. A. J. , Joosten L. A. B. , Arntz O. J. , Varley A. W. , Munford R. S. , van den Berg W. B.
Published: October 2002

Objective

To achieve disease‐inducible expression of recombinant antiinflammatory proteins in order to allow autoregulation of drug dose by natural homeostatic mechanisms.

Methods

We compared the inducible 2‐component expression system (C3–human immunodeficiency virus/transactivator of transcription [C3‐Tat/HIV]) with the constitutive cytomegalovirus (CMV) promoter in the polyarticular collagen‐induced arthritis (CIA) model in mice. DBA/1 mice were immunized with bovine type II collagen and were given boosters on day 21. On day 22, mice were injected intraarticularly with the adenoviral vectors AdCMVLuc, AdCMVhIL‐1Ra, AdC3‐Tat/HIV‐Luc, or AdC3‐Tat/HIV‐hIL‐1Ra. The injected knee joints and hind paws were then scored for signs of arthritis, and knee joint histology was compared.

Results

The CMV‐driven interleukin‐1 receptor antagonist (IL‐1Ra) expression resulted in a high constitutive expression and amelioration of CIA. C3‐Tat/HIV–driven IL‐1Ra expression could be detected only on days 24, 29, and 35. Fourteen days after injection of the vectors, CIA was significantly better inhibited by the C3‐Tat/HIV–driven IL‐1Ra expression compared with the CMV‐driven IL‐1Ra expression. Moreover, prevention of CIA in the knee joints also prevented CIA in the untreated hind paws.

Conclusion

Our data demonstrate for the first time the feasibility of an inducible expression system for local production of IL‐1Ra for treatment of arthritis in the CIA model.
Long‐term outcome in rheumatoid arthritis: A simple algorithm of baseline parameters can predict radiographic damage, disability, and disease course at 12‐year followup
Authors: Drossaers‐Bakker K. W. , Zwinderman A. H. , Vlieland T. P. M. Vliet , Van Zeben D. , Vos K. , Breedveld F. C. , Hazes J. M. W.
Published: October 2002

Objectives

To predict the long‐term outcome of rheumatoid arthritis (RA) with respect to radiographic damage, disability, and disease course using baseline variables, and to construct decision trees identifying patients on an individual level at the extremes of the outcome spectrum of these 3 dimensions.

Methods

The 12‐year outcome of 112 female RA patients from a prospective inception cohort was assessed by measuring the tertiles of radiographic damage (measured by the modified Sharp/van der Heijde method, SHS), disability (measured by the Health Assessment Questionnaire, HAQ), and severe disease course as defined by patients with either the 33% highest cumulative disease activity (area under the curve of all observed disease activity scores) or the highest tertile of radiographic damage. Patients in the lowest (mild) and highest tertile (severe) of each outcome measure were identified. All baseline parameters known to be associated with each outcome (demographic and socioeconomic parameters; disease duration; disease activity measures; laboratory measures including rheumatoid factor, HLA typing, percentage agalactosyl IgG, functional and radiographic measures) were entered into cross‐validated stepwise logistic regression models to find the best predictive combination of baseline parameters for each of the outcomes. Using the results of the logistic regression models, simple decision trees were constructed to categorize patients at an individual level in a particular prognostic group.

Results

After 12 years, the lowest and highest tertiles were, respectively, 42.3 and 189 for the SHS and 0.37 and 1.25 for the HAQ. Fifty‐five patients had a severe disease course. Mild and severe radiographic damage could be predicted with an accuracy of 90% and 85%, respectively. Mild and severe HAQ could be predicted with an accuracy of 90% and 84%, respectively, and severe disease course with an accuracy of 81%. The baseline variables found to be predictive of all 3 outcome measures were very similar and consisted of combinations of the following baseline parameters: swollen joint count (SJC), Ritchie score, rheumatoid factor (RF), the presence of erosions, and the HAQ score. Additional knowledge of the HLA typing hardly improved the accuracy of the prediction. To predict outcome at the individual level, simple decision trees were constructed using the RF, HAQ, SJC, and presence of erosions at baseline.

Conclusion

The present study shows that prediction of outcome in long‐term RA is possible and can be done using widely available baseline parameters.
Development and evaluation of a single value score to assess global range of motion in juvenile idiopathic arthritis
Authors: Epps Heather , Hurley Mike , Utley Martin
Published: October 2002

Objectives

To develop a global range of motion score (GROMS) and to investigate the association between this newly developed measure of joint range of motion and physical function in children with active juvenile idiopathic arthritis (JIA).

Methods

Two scales were calculated, 1 measuring 56 selected joints and 1 measuring 10 joints assessed as important to function by experts from the British Paediatric Rheumatology Group. These were measured in 50 patients with JIA whose disability was assessed using the Child Health Assessment Questionnaire (CHAQ).

Results

The GROMS measuring all joints and the GROMS measuring 10 joints closely agreed with each other, and both GROMS correlated significantly with the CHAQ (r = −0.52 and −0.62, respectively).

Conclusion

The 10‐joint GROMS is a simple, easy‐to‐use tool that measures overall change in joint range of motion that affects physical function in JIA.
Short‐term outcomes of acute knee injuries: Does the provider make a difference?
Authors: Amadio Peter C. , Gabriel Sherine E. , Yawn Barbara P. , Harmsen W. Scott , Ilstrup Duane M. , Hill Jeannie
Published: October 2002

Objective

To compare the short‐term outcomes of acute knee injuries treated by specialists and generalists.

Methods

Using patient logs, 168 adults with acute knee injuries were identified; 131 (78%) completed a questionnaire 3 months after initial presentation.

Results

The mean age of the 77 male and 54 female responders was 34.6 years (range 18–73 years). The injuries were classified as mild (n = 35), moderate (n = 75), or severe (n = 21). Most responders were satisfied with their care and outcome, but 22% noted some functional limitations. The 59 patients seeing an orthopedist were more likely to have had a severe injury, more physician visits, activity limitations, lost time from work or recreation, and more pain when compared with the 72 patients who never saw an orthopedist. Excluding surgical patients, however, satisfaction was not significantly different by provider. After multivariate modeling (adjusting for age, sex, injury severity, and diagnosis), there was no significant association between having seen an orthopedist and either treatment success or satisfaction.

Conclusion

With the exception of time lost for recuperation in our community there is little difference in short‐term outcome for patients with acute knee injury not undergoing surgery, regardless of the specialty of the treating physician.
Relevance of Web documents: Ghosts consensus method
Authors: Gorbunov Andrey L.
Published: October 2002

The dominant method currently used to improve the quality of Internet search systems is often called “digital democracy.” Such an approach implies the utilization of the majority opinion of Internet users to determine the most relevant documents: for example, citation index usage for sorting of search results (google.com) or an enrichment of a query with terms that are asked frequently in relation with the query's theme. “Digital democracy” is an effective instrument in many cases, but it has an unavoidable shortcoming, which is a matter of principle: the average intellectual and cultural level of Internet users is very low—everyone knows what kind of information is dominant in Internet query statistics. Therefore, when one searches the Internet by means of “digital democracy” systems, one gets answers that reflect an underlying assumption that the user's mind potential is very low, and that his cultural interests are not demanding. Thus, it is more correct to use the term “digital ochlocracy” to refer to Internet search systems with “digital democracy.” Based on the well‐known mathematical mechanism of linear programming, we propose a method to solve the indicated problem.
Is epinephrine administration by sublingual tablet feasible for the first‐aid treatment of anaphylaxis? A proof‐of‐concept study
Authors: Gu Xiaochen , Simons Keith J. , Simons F. Estelle R.
Published: October 2002

Purpose: In order to explore the feasibility of sublingual administration of epinephrine tablets as a non‐invasive first‐aid treatment for anaphylaxis, we studied epinephrine absorption from this dosage form in an animal model. Methods: In a prospective, randomized, four‐way crossover study, six rabbits received epinephrine 2.5 or 10 mg as a sublingual tablet, epinephrine 0.03 mg (0.3 ml) by intramuscular (IM) injection (positive control), and 0.9% NaCl (0.3 ml) IM (negative control). Pre‐ and post‐dose blood samples were obtained for measurement of plasma epinephrine concentrations by HPLC‐EC. Results: After administration of epinephrine 2.5 mg as a sublingual tablet, the mean (±SEM) Cmax was 2369±392 pg/ml, and the tmax was 20.8±5.7 min. After administration of epinephrine 10 mg sublingually, the Cmax was 10836±2234 pg/ml, and the tmax was 21.7±5.4 min. After IM epinephrine, the Cmax was 6445±4233 pg/ml, and the tmax was 15.8±4.7 min. After IM 0.9% NaCl, the Cmax (endogenous epinephrine) was 518±142 pg/ml. The tmax after both of the sublingual epinephrine tablet doses did not differ significantly from the tmax after IM epinephrine, and the Cmax after the 10 mg sublingual epinephrine tablet dose did not differ significantly from the Cmax after IM epinephrine. Conclusions: In this proof‐of‐concept study, administration of epinephrine as a sublingual tablet formulation resulted in rapid achievement of peak plasma epinephrine concentrations. Absorption studies in humans are needed.

Definitions: HPLC—high performance liquid chromatography; EC — electrochemical detection; Cmax — maximum plasma epinephrine concentration after dosing; tmax — time of maximum plasma epinephrine concentration. Copyright © 2002 John Wiley & Sons, Ltd.
Studies of 50 Hz circularly polarized magnetic fields of up to 350 μT on reproduction and embryo‐fetal development in rats: Exposure during organogenesis or during preimplantation
Authors: Negishi Tadashi , Imai Setsuo , Itabashi Masafumi , Nishimura Izumi , Sasano Takao
Published: October 2002

Groups of mated female Sprague–Dawley rats were simultaneously exposed to 0 (sham exposed), 7, 70, or 350 μT (rms) circularly polarized 50 Hz magnetic fields (MF) for 22 h/day on gestational day 8–15, the period of rat fetal organogenesis (organogenesis study) or from day 0 to day 7 of gestation, the rat preimplantation period (preimplantation study). Developmental toxicity was assessed on gestational day 20. Identical experiments were repeated to confirm reproducibility of both studies. In both studies, statistically significant differences between exposed and sham exposed animals were observed in several measured parameters; however, these differences only appeared in one, but not both replicate experiments and generally at only an isolated exposure level. Because these differences were not reproducible and did not show a dose response relationship, they were not considered related to MF exposure. In the organogenesis study, lower kidney weights of dams were seen at 70 and 350 μT in Experiment 1. Lower dam liver weights and lower mean body weights of viable female and male fetuses were seen at 70 μT in Experiment 2. Otherwise, there were no differences in these parameters or in group means for fetal loss after implantation, number of viable fetuses, fetal body weight and sex ratio, incidences of external, visceral, and skeletal abnormalities or variations, or tissue abnormalities after histopathological examination. In the preimplantation study, dam health and indices for reproduction and embryo‐fetal development, including pre or postimplantation loss, number and body weight of live fetuses, and sex ratio, external, skeletal abnormalities and variations, and skeletal ossification did not differ. Dam inorganic phosphorous concentration at 350 μT was elevated in one experiment and depressed in another. In one experiment, visceral abnormalities, primarily thymic remnant in neck and accessory liver lobe, were increased in the 7 μT group. Based on these results from two studies, we conclude that circularly polarized 50 Hz MF exposure of up to 350 μT during the fetal organogenesis or during the preimplantation period does not affect reproduction and embryo‐fetal development in Sprague–Dawley rats. Bioelectromagnetics 23:369–389, 2002. © 2002 Wiley‐Liss, Inc.
Potential motion related bias in the worn dosimeter measurements of two childhood leukemia studies
Authors: Leeper Ed , Wertheimer Nancy
Published: October 2002

Time averaged field measurements produced by a Positron™ dosimeter worn by study subjects was the primary method of exposure evaluation in two Canadian studies of childhood leukemia and AC magnetic field exposure. Statistically significant but mutually contradictory results obtained in the two studies, done in different locales but under similar study conditions, have not been explained. This report examines operational features of the Positron meter, including an unanticipated sensitivity to wearer motion. If the convalescent cases studied were less active than their healthy controls, as one might expect, then the meter's characteristic responses to motion, particularly as they would affect case‐control distributions above and below the different referent group cutpoints used in the two studies, could help to explain both the unexpected inverse risks reported in the larger study and the unusually high risks reported in the smaller study. Bioelectromagnetics 23:390–397, 2002. © 2002 Wiley‐Liss, Inc.