bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of molecular weight on electroluminescence of nanogold‐bonded poly(9,9‐dioctylfluorene‐alt‐thiophene) at a constant polymer‐to‐gold weight ratio
Authors: Ji Hong‐Da , Tu Yen‐Ching , Wu Sheng‐Han , Liu Cheng‐Hao , Su Yu‐Wei , Tsiang Raymond Chien‐Chao
Published: May 2009

The effects of molecular weight on electroluminescent properties of the light emitting polymeric nanocomposite, poly(9,9‐dioctylfluorene‐alt‐thiophene) with chemically bonded gold nanoparticles (PDOFT‐Au), have been studied under a condition of constant polymer‐to‐gold weight ratio. The polymer, PDOFT, was first synthesized via the Suzuki cross‐coupling reaction and then bonded to in situ‐formed gold nanoparticles (AuNPs) via terminal thiol functional groups which had been generated during the quenching of polymerization. A series of PDOFT‐Au's of various molecular weights have thus been synthesized. At a constant polymer‐to‐gold weight ratio, the average size of gold nanoparticles (AuNPs) increased with an increase in the molecular weight of PDOFT. Although an increased molecular weight led to a red shift in UV‐absorption and PL spectra as well as an increased PL quantum efficiencies (ϕPL) for all samples (both PDOFT and PDOFT‐Au), the effect of AuNPs bonding became more noticeable when the molecular weight was higher. As for light emitting diode (LED) device fabrication, an increase in the molecular weight of PDOFT also led to a red shift in the EL spectra of the fabricated LED devices. Nevertheless, PDOFT‐Au, compared with PDOFT, had a lower threshold voltage, an increased brightness and current density, and an improved photometric efficiency. Moreover, the photometric efficiency increased with an increase in the molecular weight of the polymer, from 0.298 cd/A for PDOFT‐Au3 up to 0.645 cd/A for PDOFT‐Au1. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Biomedical property modifications of poly(vinyl chloride) with methoxylated poly(ethylene glycol)‐poly(ε‐caprolactone) diblock copolymer
Authors: Zhang Tao , Pan Meiyu , Dai Ji , Song Zhexian , He Ling , Jiang Zhengsheng
Published: May 2009

Manufacturing biomedical flexible Poly (vinyl chloride) (PVC) products requires the nontoxic plasticizers and the biocompatibility. In this study, a series of methoxylated poly(ethylene glycol)‐poly(ε‐caprolactone) diblock copolymer (MPEG‐PCL) with variety molecule weight were synthesized by ring‐opening polymerization of ε‐caprolactone with methoxylated poly(ethylene glycol) (MPEG) as macroinitiator. The structure of the block copolymers was characterized utilizing FTIR, NMR, SEC, and DSC. Because the compatibility between PVC and PCL, a series of MPEG‐PCL/PVC blends were prepared. The results of DSC and mechanical properties of blends show that PVC could be plasticized with MPEG‐PCL and the diblock copolymer is probably to be used as a polymeric plasticizer for PVC. Moreover, the water contact angle results indicated that MPEG‐PCL also provided PVC the hydrophilic properties. At the same time, it was found that the blends showed favorable anticoagulation property which can probably exploit the potential application of the blends in the biomedical areas. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Synthesis, characterization, and application of composite alginate microspheres with magnetic and fluorescent functionalities
Authors: Liu Jiwei , Zhang Yu , Yang Ting , Ge Yuqing , Zhang Song , Chen Zhongping , Gu Ning
Published: May 2009

Composite alginate microspheres were synthesized via a modified emulsification technique and characterized by inverted optical microscope, transmission electron microscope, ζ‐potential analyzer, UV–vis spectrophotometer, luminescence spectrometer, and vibrating sample magnetometer. The results show that the synthetic parameters including the weight ratio of maghemite nanoparticles to alginate, hydrophile‐lipophile balance (HLB) value, stirring speed, and CaCl2 dripping rate play important roles in the synthesis of microspheres. Furthermore, the composite alginate microspheres exhibit good superparamagnetism and fluorescence, which can serve both as magnetic resonance contrast agents and optical probes for biological imaging. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Effects of ingredients on thermal and mechanical properties of acrylic bone cements
Authors: Endogan Tugba , Serbetci Kemal , Hasirci Nesrin
Published: May 2009

There is a very delicate relation between the amounts of all the ingredients present in the cement composition and the properties of the product. In this study, homogeneous poly(methyl methacrylate) (PMMA) microspheres were prepared by suspension polymerization technique, and used in cement formulations. Various acrylic cements with different compositions were prepared by using PMMA microspheres, methyl methacrylate (MMA) monomer, radiopaque agent of barium sulfate (BaSO4), inorganic particles of hydroxyapatite (HA), initiator and chain stopping agent of 1‐dodecyl mercaptan (DDM). The effects of these additives on mechanical and thermal properties of the resultant cements were examined. Addition of 8% HA relative to the solid parts caused an increase in both tensile and compressive strengths from 20.40 to 25.20 MPa, and from 84.04 to 89.57 MPa, respectively, while curing temperature was decreased about 3 degrees. Chain stopping agent of DDM caused a sharp decrease about 30 degrees in the curing temperature. Radiopaque agent of barium sulfate caused inverse effect on mechanical and thermal properties. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
The totally miscible in ternary hydrogen‐bonded polymer blend of poly(vinyl phenol)/phenoxy/phenolic
Authors: Kuo Shiao‐Wei
Published: May 2009

The individual binary polymer blends of phenolic/phenoxy, phenolic/poly(vinyl phenol) (PVPh), and phenoxy/PVPh have specific interaction through intermolecular hydrogen bonding of hydroxyl–hydroxyl group to form homogeneous miscible phase. In addition, the miscibility and hydrogen bonding behaviors of ternary hydrogen bond blends of phenolic/phenoxy/PVPh were investigated by using differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy, and optical microscopy. According to the DSC analysis, every composition of the ternary blend shows single glass transition temperature (Tg), indicating that this ternary hydrogen‐bonded blend is totally miscible. The interassociation equilibrium constant between each binary blend was calculated from the appropriate model compounds. The interassociation equilibrium constant (KA) of each individually binary blend is higher than any self‐association equilibrium constant (KB), resulting in the hydroxyl group tending to form interassociation hydrogen bond. Photographs of optical microscopy show this ternary blend possess lower critical solution temperature (LCST) phase diagram. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Polyurethane networks from different soy‐based polyols by the ring opening of epoxidized soybean oil with methanol, glycol, and 1,2‐propanediol
Authors: Wang Cheng‐Shuang , Yang Li‐Ting , Ni Bao‐Lian , Shi Guang
Published: May 2009

A series of polyols with a range of hydroxyl (OH) numbers based on soybean oil and epoxidized soybean oil were prepared by oxirane ring opening with methanol, glycol, and 1,2‐propanediol. The polyols, with average functionalities varying from 2.6 to 4.9, were characterized. Novel cast polyurethane resins were synthesized from these polyols and 2,4‐toluene diisocyanate. The sol fraction of the network decreased as the OH number of the polyol from which it was synthesized increased. None of the samples were completely soluble. The crosslinking density of the polyurethanes correlated directly with the functionality of the polyols. The thermal and mechanical properties of the cast resins were characterized with differential scanning calorimetry and thermogravimetry. The glass‐transition temperature increased with the OH number increasing, and the thermal stability of the resins was slightly decreased with the OH number increasing. The tensile strength at break increased with the OH number increasing. Polyurethanes prepared from polyols with OH numbers higher than 170 mg of KOH/g were glassy, whereas those with OH numbers below that value were rubbery. Glassy polyurethanes displayed decent mechanical strength, whereas rubbery samples showed relatively poor elastic properties and were characterized by lower strength. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Solubilization and polymer analogous reactions of polyepichlorohydrin in ionic liquids
Authors: Kim Byoung Gak , Sohn Eun‐Ho , Chung Jae‐Seung , Kwak Seung‐Yeop , Lee Jong‐Chan
Published: May 2009

Polyepichlorohydrin containing reactive chloromethyl side groups was found to be highly soluble in polar ionic liquids containing halide anions such as 1‐n‐butyl‐3‐methyl imidazolium chloride, 1‐n‐ethyl‐3‐methyl imidazolium bromide, and 1‐n‐hexyl‐3‐methyl imidazolium chloride, whereas it was insoluble in less polar ionic liquids such as 1‐n‐butyl‐3‐methyl imidazolium tetrafluoroborate and 1‐n‐butyl‐3‐methyl imidazolium hexafluorophosphate. The reaction of polyepichlorohydrin with thiolates and thiol compounds in the polar ionic liquids as reaction media produced polyoxyethylenes with thioether side groups in very high conversions and yields. When polyepichlorohydrin was reacted with sodium 1H,1H,2H,2H‐perfluorinated decanethiolate in 1‐n‐hexyl‐3‐methyl imidazolium chloride at 70°C and the product was separated through centrifugation, the ionic liquid could be used more than four times, and high conversions (>70 mol %) and yields (>62 wt %) were maintained. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Multiparameter solution model and evaluation of polymer–polymer miscibility using inverse gas chromatography data
Authors: Huang Jan‐Chan
Published: May 2009

Inverse gas chromatography (IGC) has been widely used to determine the Flory–Huggins parameters, χ, between solutes (probes) and polymers. This study correlated the Flory–Huggins parameter data using a multiparameter model, which included dispersion, polarity, acidity, and basicity components. The parameters of poly(ε‐caprolactone) (PCL) and polyepichlorohydrin (PECH) were calculated from IGC data using a series of probes. The parameters of the polymers were used to evaluate mutual miscibility between PCL and PECH. The results predicted miscibility in agreement with the conclusion of an IGC study using blends of PCL and PECH. A method to estimate the confidence interval of polymer parameters was proposed. The anomalous solubility parameter of polymer mixtures previously reported was also explained using this model. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Role of amphiphilic dopants on the shape and properties of electrically conducting polyaniline‐clay nanocomposite
Authors: Reena Viswan L. , Sudha Janardhanan D. , Pavithran Chorappan
Published: May 2009

The role of functionality and rigidity of the amphiphilic dopants on the morphology and electrical property of the polyaniline‐clay nanocomposites (PANICNs) were studied by preparing polyaniline (PANI) and PANICNs using five structurally different amphiphilic dopants having backbone—phenyl, naphthyl, alicyclic, and alkyl groups. Effect of the size and functionality of the dopant on the extent of intercalation/exfoliation, morphology, thermal stability, and phase transitions were studied. PANICNs exhibited different morphologies such as nano/micro granules, rods, nanotubes, aggregated layers/clusters, and rice grain for PANICN‐2,6‐naphthalene sulphonic acid, PANICN‐para‐toluene sulphonic acid, PANICN‐stearic acid, PANICN‐dodecyl benzene sulphonic acid, and PANICN‐camphor sulphonic acid, respectively. X‐ray diffraction, Fourier transform infrared, and scanning electron microscopic studies showed that the self‐assembled nano/microstured aggregates were formed by the combined effect of many noncovalent interactions such as phenyl–phenyl stacking, hydrogen bonding, ion–dipole interaction, π–π stacking, and electrostatic layer‐by‐layer self‐assembling. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009.
Crystallization kinetics of poly(L‐lactide)/carbonated hydroxyapatite nanocomposite microspheres
Authors: Zhou Wen You , Duan Bin , Wang Min , Cheung Wai Lam
Published: May 2009

Microspheres consisting of carbonated hydroxyapatite (CHAp) nanoparticles and poly(L‐lactide) (PLLA) have been fabricated for use in the construction of osetoconductive bone tissue engineering scaffolds by selective laser sintering (SLS). In SLS, PLLA polymer melts and crystallizes. It is therefore necessary to study the crystallization kinetics of PLLA/CHAp nanocomposites. The effects of 10 wt% CHAp nanoparticles on the isothermal and nonisothermal crystallization behavior of PLLA matrix were studied, using neat PLLA for comparisons. The Avrami equation was successfully applied for the analysis of isothermal crystallization kinetics. Using the Lauritzen‐Hoffman theory, the transition temperature from crystallization Regime II to Regime III was found to be around 120°C for both neat PLLA and PLLA/CHAp nanocomposite. The combined Avrami‐Ozawa equation was used to analyze the nonisothermal crystallization process, and it was found that the Ozawa exponent was equal to the Avrami exponent for neat PLLA and PLLA/CHAp nanocomposite, respectively. The effective activation energy as a function of the relative crystallinity and temperature for neat PLLA and PLLA/CHAp nanocomposite under the nonisothermal crystallization condition was obtained by using the Friedman differential isoconversion method. The Lauritzen‐Hoffman parameters were also determined from the nonisothermal crystallization data by using the Vyazovkin‐Sbirrazzuoli equation. CHAp nanoparticles in the composite acted as an efficient nucleating agent, enhancing the nucleation rate but at the same time reducing the spherulite growth rate. This investigation has provided significant insights into the crystallization behavior of PLLA/CHAp nanocomposites, and the results obtained are very useful for making good quality PLLA/CHAp scaffolds through SLS. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Covalent immobilization of β‐galactosidase on carrageenan coated with chitosan
Authors: Elnashar Magdy M.M. , Yassin Mohamed A.
Published: May 2009

β‐Galactosidase was covalently immobilized to carrageenan coated with chitosan for the hydrolysis of lactose. The chitosan‐carrageenan polyelectrolyte interaction was found to be dependent on the chitosan pH. At pH 4, the chitosan reached its maximum binding of 28.5% (w/w) where the chitosan surface density was 4.8 mg chitosan/cm2 g of carrageenan gel disks, using Muzzarelli method. Glutaraldehyde was used as a mediator to incorporate new functionality, aldehydic carbonyl group, to the bio‐polymers for covalent attachment of β‐galactosidase. The enzyme was covalently immobilized to the biopolymer at a concentration of 2.73 mg protein per g of wet gel. FTIR proved the incorporation of the aldehydic carbonyl group to the carrageenan coated with chitosan at 1720 cm−1. The optimum time for enzyme immobilization was found to be 16 h, after which a plateau was reached. The enzyme loading increased from 2.65 U/g (control gel) to 10.92 U/g gel using the covalent technique.

The gel's modification has shown to improve the carrageenan gel thermal stability as well as the immobilized enzyme. For example, the carrageenan gel treated with chitosan showed an outstanding thermal stability at 95°C compared with 35°C for the untreated carrageenan gel. Similarly, the immobilization process shifted the enzyme's optimum temperature from 50°C for the free enzyme towards a wider temperature range 45–55 °C indicating that the enzyme structure is strengthened by immobilization. In brief, the newly developed immobilization method is simple; the carrier is cheap, yet effective and can be used for the immobilization of other enzymes. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
New compatibilizer for linear low‐density polyethylene (LLDPE)/clay nanocomposites
Authors: Jin Dong‐Woo , Seol Sung‐Mok , Kim Gue‐Hyun
Published: May 2009

Linear low‐density polyethylene (LLDPE) is one of the most widely used polymers in many fields, but it is difficult to prepare LLDPE/clay nanocomposites because of the hydrophobic nature of LLDPE. In this study, the effectiveness of low molecular weight trimethoxysilyl‐modified polybutadiene (Organosilane) as a compatibilizer for LLDPE/clay nanocomposites was studied using X‐ray diffraction (XRD) and correlated with mechanical properties. Organosilane is known to react with dicumyl peroxide (DCP) to form free radicals, which react with LLDPE increasing the polarity of the LLDPE. Based on XRD and mechanical tests, it was concluded that Organosilane is a good compatibilizer for LLDPE and clay. Also when Organosilane was used in preparing LLDPE/clay nanocomposite foams, most mechanical properties were improved. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
A simple method to obtain a swollen PVA gel crosslinked by hydrogen bonds
Authors: Otsuka Emiko , Suzuki Atsushi
Published: May 2009

A simple method to obtain a physically crosslinked poly(vinyl alcohol) (PVA) hydrogel is reported. In this technique, the PVA solution in pure water was simply cast at room temperature without using any additional chemical. The gelation proceeded during the dehydration after casting the PVA solution into a mold. After the completion of gelation, the swelling ratio of the gel in its equilibrium was measured whenever the solvent water was repeatedly exchanged. The weight gradually decreased due to the elution of non‐crosslinked polymers into the solvent, and became constant after sufficient water exchange. The measurements using a Fourier Transform infrared spectroscopy and an X‐ray diffraction suggested that the crosslinks due to hydrogen bonds and microcrystals were formed during the dehydration process of the PVA solution. We concluded that the sample obtained by the present method is a physically crosslinked polymer network, insoluble in water, i.e., a swollen gel in water. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Graft copolymerization of itaconic acid onto sodium alginate using ceric ammonium nitrate as initiator
Authors: Işıklan Nuran , Kurşun Fatma , İnal Murat
Published: May 2009

Graft copolymers of sodium alginate (NaAlg) with itaconic acid (IA) were prepared in aqueous solution using ceric ammonium nitrate (CAN) as the redox initiator under N2 atmosphere. The carboxylic acid groups of IA were neutralized with sodium hydroxide before grafting process. Grafted copolymers as sodium salts (NaAlg‐g‐PIA) were characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, intrinsic viscosity measurement, differential scanning calorimetry, and thermogravimetric analysis. The graft yield (GY %) of the graft copolymer and the grafting efficiency (GE %) of the reaction were evaluated comparatively. The effects of the reaction variables such as the reaction time, temperature, percentage of NaAlg, monomer and initiator concentrations on these parameters were studied. It was observed that GY% and GE% increased and then decreased with increasing concentrations of IA and polymerization temperature. The optimum grafting conditions for maximum GY were obtained with a reaction time of 5 h, reaction temperature of 30°C, IA concentration of 0.23 M, CAN concentration of 9.12 × 10−2 M and percentage of NaAlg 0.5 g/dL. The overall activation energy for the grafting was also calculated to be 1135 cal/mol. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Semi‐ and full‐interpenetrating polymer networks based on polyurethane produced from canola oil and poly(methyl methacrylate)
Authors: Kong Xiaohua , Tan Susheng , Narine Suresh S.
Published: May 2009

Semi‐ and full‐interpenetrating polymer networks (IPNs) were prepared using polyurethane (PUR) produced from a canola oil‐based polyol with primary terminal functional groups and poly(methyl methacrylate) (PMMA). The properties of the material were studied and compared using dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), and tensile measurements. The morphology of the IPNs was investigated using atomic force microscopy (AFM). Semi‐IPNs demonstrated different thermal mechanical properties, mechanical properties, phase behavior, and morphology from full IPNs. Both types of IPNs studied are two‐phase systems with incomplete phase separation. However, the extent of phase separation is significantly more advanced in the semi‐IPNs compared with the full IPNs. All the semi‐IPNs exhibited higher values of elongation at break for all proportions of acrylate to polyurethane compared with the corresponding full IPNs. These differences are mainly due to the fact that in the case of semi‐IPNs, one of the constituting polymers remains linear, so that it exhibits a loosely packed network and relatively high mobility, whereas in the case of full IPNs, there is a higher degree of crosslinking, which restricts the mobility of the chains. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Architecture of the Blood‐Spleen Barrier in the Soft‐Shelled Turtle, Pelodiseus Sinensis
Authors: Bao Hui‐Jun , Li Mei‐Ying , Wang Jiang , Qin Jun‐Hui , Xu Chun‐Sheng , Hei Nai‐Nan , Yang Ping , Gandahi J.A. , Chen Qiu‐Sheng
Published: May 2009

We investigated the structure of the soft‐shelled turtle, Pelodiseus sinensi, spleen and demonstrated that there were several microanatomical peculiarities by light and transmission electron microscopy. In the spleen, the white pulp of the spleen was composed of two compartments, the periarteriolar lymphatic sheath (PALS) and periellipsoidal lymphatic sheath (PELS). No lymph nodules and marginal zones were found. The spleen‐blood barrier stood in the PELS and the ellipsoid. The high endothelial lining of penicilliform capillary contained small channels. These channels allowed circulating substances or lymphocytes to enter the ellipsoid. The distal portion of the penicilliform capillaries directly opened to pulp cords. The ellipsoid‐associated cell (EAC) was located at the surface of the ellipsoid. Reticular fibers were mainly distributed in ellipsoid and the outer PELS. Both reticular cells and macrophages were distributed in the outer layers of PELS. S‐100 protein positive dendritic cells were mainly distributed in out cells layer of the PELS and all over the PALS. Forty minutes after injection, carbon particles of Indian ink were mainly observed in the ellipsoid. Few carbon particles were observed in the outer PELS and fewer carbon particles in the red pulp. These findings suggested that a blood‐spleen barrier indeed existed in the soft‐turtle, P. sinensi, and it was a complex composed of an ellipsoid (including supporting cells, EAC, and reticular fibers) and the outer compartments of PELS (including dendritic cells, reticular fibers and cells, macrophages). Anat Rec, 2009. © 2009 Wiley‐Liss, Inc.
Bactrocerin‐1: A novel inducible antimicrobial peptide from pupae of oriental fruit flyBactrocera dorsalisHendel
Authors: Dang Xiang‐Li , Tian Jin‐Huan , Yang Wan‐Ying , Wang Wen‐Xian , Ishibashi Jun , Asaoka Ai , Yi Hui‐Yu , Li Yi‐Feng , Cao Yang , Yamakawa Minoru , Wen Shuo‐Yang
Published: May 2009

A novel antimicrobial peptide, Bactrocerin‐1, was purified and characterized from an immunized dipteran insect,Bactrocera dorsalis. Bactrocerin‐1 has 20 amino acid residues with a mass of 2,325.95 Da. The amino acid sequence of Bactrocerin‐1 showed very high similarity to the active fragment (46V‐65S‐NH2) of Coleoptericin A. The composition of amino acid residues revealed that Bactrocerin‐1 is a hydrophobic, positively charged, and Lys/Ile/Gly‐rich peptide. Minimal growth inhibition concentration (MIC) measurements for synthesized Bactrocerin‐1 showed a very broad spectrum of anti‐microbial activity against Gram‐positive bacteria, Gram‐negative bacteria, and fungi. Bactrocerin‐1 did not show hemolytic activity toward mouse red blood cells even at a concentration of 50 µM. Analysis of the Helical‐wheel projection and the CD spectrum suggested that Bactrocerin‐1 contains the amphipathic α‐helix. © 2009 Wiley Periodicals, Inc.
The importance of starch and sucrose digestion in nutritive biology of synanthropic acaridid mites: α‐Amylases and α‐glucosidases are suitable targets for inhibitor‐based strategies of mite control
Authors: Erban Tomas , Erbanova Michaela , Nesvorna Marta , Hubert Jan
Published: May 2009

The adaptation of nine species of mites that infest stored products for starch utilization was tested by (1) enzymatic analysis using feces and whole mite extracts, (2) biotests, and (3) inhibition experiments. Acarus siro, Aleuroglyphus ovatus, and Tyroborus lini were associated with the starch‐type substrates and maltose, with higher enzymatic activities observed in whole mite extracts. Lepidoglyphus destructor was associated with the same substrates but had higher activities in feces. Dermatophagoides farinae, Chortoglyphus arcuatus, and Caloglyphus redickorzevi were associated with sucrose. Tyrophagus putrescentiae and Carpoglyphus lactis had low or intermediate enzymatic activity on the tested substrates. Biotests on starch additive diets showed accelerated growth of species associated with the starch‐type substrates. The inhibitor acarbose suppressed starch hydrolysis and growth of the mites. We suggest that the species with higher starch hydrolytic activity in feces were more tolerant to acarbose, and α‐amylase and α‐glucosidase of synanthropic mites are suitable targets for inhibitor‐based strategies of mite control. © 2009 Wiley Periodicals, Inc.
Synthesis, Antiviral and Cytostatic Evaluation of Unsaturated Exomethylene and Keto D‐Lyxopyranonucleoside Analogues
Authors: Tzioumaki Niki , Tsoukala Evangelia , Manta Stella , Agelis George , Balzarini Jan , Komiotis Dimitri
Published: May 2009

This report describes the synthesis of unsaturated exomethylene lyxopyranonucleoside analogues as potential biologically active agents. Commercially available 1,2,3,4‐tetra‐O‐acetyl‐α‐D‐lyxopyranose 1 was condensed with silylated thymine and uracil, respectively, deacetylated and acetalated to afford 1‐(2,3‐O‐isopropylidene‐α‐D‐lyxopyranosyl)thymine 4a and 1‐(2,3‐O‐isopropylidene‐α‐D‐lyxopyranosyl)uracil 4b. The new derivatives 1‐(2,3,4‐trideoxy‐4‐methylene‐α‐pent‐2‐enopyranosyl)thymine 8a and 1‐(2,3,4‐trideoxy‐4‐methylene‐α‐pent‐2‐enopyranosyl)uracil 8b were prepared via two different key intermediates, 7a, b and 13a, b in order to elucidate the influence of 2′,3′‐unsaturation and to clarify the difference between the keto and exomethylene group on the biological activity of the target molecules. Compounds 7a, b, 8a, b, and 13a, b were evaluated for their antiviral and cytostatic activity using several virus strains and cell lines. Whereas no marked antiviral activity was noticed, 13a and 13b showed a cytostatic activity that ranged between 7 and 23 μM for 13a and 26 and 38 μM for 13b against murine leukemia L1210, human lymphocyte Molt4/C8 and CEM cells, and human breast carcinoma MCF7 cells.
Association of concomitant fibromyalgia with worse disease activity score in 28 joints, health assessment questionnaire, and short form 36 scores in patients with rheumatoid arthritis
Authors: Ranzolin Aline , Brenol João Carlos Tavares , Bredemeier Markus , Guarienti Jairo , Rizzatti Marcele , Feldman Daniel , Xavier Ricardo Machado
Published: May 2009

Objective

To study the association of the presence of fibromyalgia (FM) with the Disease Activity Score in 28 joints (DAS28), the Health Assessment Questionnaire (HAQ), and the Medical Outcomes Study Short Form 36 (SF‐36) health survey in patients with rheumatoid arthritis (RA).

Methods

A total of 270 outpatients with RA were enrolled in a prospective cross‐sectional study. The patients underwent clinical evaluation and application of the HAQ and SF‐36 questionnaires. Disease activity was evaluated using the DAS28 score. FM and RA diagnoses were made according to American College of Rheumatology criteria.

Results

The overall prevalence of FM was 13.4%. This group of patients had a higher prevalence of female sex, older mean age, higher functional class, and longer morning stiffness than patients with only RA. Mean ± SD DAS28 scores were significantly higher in patients with RA and FM (5.36 ± 0.99) than in patients with RA only (4.03 ± 1.39; P < 0.001). In a multivariable linear regression analysis, FM was an important predictor of the DAS28 score, even after adjusting for the erythrocyte sedimentation rate, number of swollen joints, functional class, number of disease‐modifying antirheumatic drugs currently in use, current dose of steroids, and articular erosions. HAQ and SF‐36 scores were also worse in patients with RA and associated FM.

Conclusion

FM is related to worse scores on the DAS28, HAQ, and SF‐36 in patients with RA. The presence of FM may have major implications in the interpretation of the DAS28 score because it is related to higher scores independently of objective evidence of RA activity.
Association of occupational activity with radiographic knee osteoarthritis and lumbar spondylosis in elderly patients of population‐based cohorts: A large‐scale population‐based study
Authors: Muraki Shigeyuki , Akune Toru , Oka Hiroyuki , Mabuchi Akihiko , En‐Yo Yoshio , Yoshida Munehito , Saika Akihiko , Nakamura Kozo , Kawaguchi Hiroshi , Yoshimura Noriko
Published: May 2009

Objective

To investigate the risk of radiographic knee osteoarthritis (OA) and lumbar spondylosis associated with occupational activity in elderly Japanese subjects using the large‐scale population‐based cohort of the Research on Osteoarthritis Against Disability (ROAD) study.

Methods

From the baseline survey of the ROAD study, 1,471 participants age ≥50 years (531 men and 940 women) living in mountainous and seacoast communities were analyzed. Information collected included a lifetime occupational history and details of specific work place physical activities. Radiographic severity at the knee and lumbar spine was determined by the Kellgren/Lawrence (K/L) grading system.

Results

The prevalence of K/L grade ≥2 knee OA and lumbar spondylosis among agricultural, forestry, and fishery workers was significantly higher than among clerical workers and technical experts in the overall population. For occupational activities, sitting on a chair had a significant inverse association with K/L grade ≥2 knee OA and lumbar spondylosis. Standing, walking, climbing, and heavy lifting were associated with K/L grade ≥2 knee OA, but were not associated with K/L grade ≥2 lumbar spondylosis. Kneeling and squatting were associated with K/L grade ≥3 knee OA.

Conclusion

This cross‐sectional study using a population‐based cohort suggests that sitting on a chair is a significant protective factor against both radiographic knee OA and lumbar spondylosis in Japanese subjects. An occupational activity that includes heavy lifting appears to have a greater effect on knee OA than on lumbar spondylosis.
A role for γ/δ T cells in a mouse model of fracture healing
Authors: Colburn Nona T. , Zaal Kristien J. M. , Wang Francis , Tuan Rocky S.
Published: May 2009

Objective

Fractures can initiate an immune response that disturbs osteoblastic and osteoclastic cellular homeostasis through cytokine production and release. The aim of our study was to investigate γ/δ T cells, innate lymphocytes known to be involved in tissue repair, as potential cellular components of the osteoimmune system's response to an in vivo model of bone injury. The absence of such cells or their effector cytokines influences the fate of other responder cells in proliferation, differentiation, matrix production, and ultimate callus formation.

Methods

Tibia fractures were created in 60 γ/δ T cell–deficient mice (also called δ T cell receptor [TCR]–knockout mice) and 60 control C57BL/6 mice. Analysis included radiographs, basic histology, mechanical testing, flow cytometry, and immunohistochemical localization of γ/δ TCR–positive subsets from control animals and of CD44 expression from both groups, as well as enzyme‐linked immunosorbent assay for the effector cytokines interleukin‐2 (IL‐2), interferon‐γ (IFNγ), and IL‐6.

Results

Animals deficient in γ/δ T cells demonstrated more mature histologic elements and quantitative increases in the expression of major bone (bone sialoprotein) and cartilage (type II collagen) matrix proteins and in the expression of bone morphogenetic protein 2 at a critical reparative phase. Moreover, only γ/δ T cell–deficient animals had a decrease in the osteoprogenitor antiproliferative cytokines IL‐6 and IFNγ at the reparative phase. The result was improved stability at the repair site and an overall superior biomechanical strength in γ/δ T cell–deficient mice compared with controls.

Conclusion

The evidence for a role of γ/δ T cells in the context of skeletal injury demonstrates the importance of the immune system's effect on bone biology, which is relevant to the field of osteoimmunology, and offers a potential molecular platform from which to develop essential therapeutic strategies.
NOD2‐Associated pediatric granulomatous arthritis, an expanding phenotype: Study of an international registry and a national cohort in spain
Authors: Rosé Carlos D. , Aróstegui Juan I. , Martin Tammy M. , Espada Graciela , Scalzi Lisabeth , Yagüe Jordi , Rosenbaum James T. , Modesto Consuelo , Cristina Arnal Maria , Merino Rosa , García‐Consuegra Julia , Carballo Silva María Antonia , Wouters Carine H.
Published: May 2009

Objective

To study the phenotype characteristics of the largest to date cohort of patients with pediatric granulomatous arthritis (PGA) and documented mutations in the NOD2 gene.

Methods

We analyzed merged data from 2 prospective cohorts of PGA patients, the International PGA Registry and a Spanish cohort. A systematic review of the medical records of interest was performed to identify phenotype characteristics.

Results

Forty‐five patients with PGA (23 sporadic cases and 22 from familial pedigrees) and documented NOD2 mutations were identified and formed the basis of the study. Of these 45 patients, 18 had the R334W‐encoding mutation, 18 had R334Q, 4 had E383K, 3 had R587C, 1 had C495Y, and 1 had W490L. The majority of patients manifested the typical triad of dermatitis, uveitis, and arthritis. In contrast, in 13 patients, the following “atypical” manifestations were noted: fever, sialadenitis, lymphadenopathy, erythema nodosum, leukocytoclastic vasculitis, transient neuropathy, granulomatous glomerular and interstitial nephritis, interstitial lung disease, arterial hypertension, hypertrophic cardiomyopathy, pericarditis, pulmonary embolism, hepatic granulomatous infiltration, splenic involvement, and chronic renal failure. In addition, 4 individuals who were asymptomatic carriers of a disease‐causing mutation were documented.

Conclusion

NOD2‐associated PGA can be a multisystem disorder with significant visceral involvement. Treating physicians should be aware of the systemic nature of this condition, since some of these manifestations may entail long‐term morbidity.
Remnants of secondarily necrotic cells fuel inflammation in systemic lupus erythematosus
Authors: Muñoz Luis E. , Janko Christina , Grossmayer Gerhard E. , Frey Benjamin , Voll Reinhard E. , Kern Peter , Kalden Joachim R. , Schett Georg , Fietkau Rainer , Herrmann Martin , Gaipl Udo S.
Published: May 2009

Objective

Patients with systemic lupus erythematosus (SLE) are often characterized by cellular as well as humoral deficiencies in the recognition and phagocytosis of dead and dying cells. The aim of this study was to investigate whether the remnants of apoptotic cells are involved in the induction of inflammatory cytokines in blood‐borne phagocytes.

Methods

We used ex vivo phagocytosis assays comprising cellular and humoral components and phagocytosis assays with isolated granulocytes and monocytes to study the phagocytosis of secondarily necrotic cell–derived material (SNEC). Cytokines were measured by multiplex bead array technology.

Results

We confirmed the impaired uptake of various particulate targets, including immunoglobulin‐opsonized beads, by granulocytes and monocytes from patients with SLE compared with healthy control subjects. Surprisingly, blood‐borne phagocytes from two‐thirds of the patients with SLE took up SNEC, which was rarely phagocytosed by phagocytes from healthy control subjects or patients with rheumatoid arthritis. Supplementation of healthy donor blood with IgG fractions derived from patients with SLE transferred the capability to take up SNEC to the phagocytes of healthy donors. Phagocytosis‐promoting immune globulins also induced secretion of huge amounts of cytokines by blood‐borne phagocytes following uptake of SNEC.

Conclusion

Opsonization of SNEC by autoantibodies from patients with SLE fosters its uptake by blood‐borne monocytes and granulocytes. Autoantibody‐mediated phagocytosis of SNEC is accompanied by secretion of inflammatory cytokines, fueling the inflammation that contributes to the perpetuation of autoimmunity in SLE.
Autoantibodies to a 140‐kd protein in juvenile dermatomyositis are associated with calcinosis
Authors: Gunawardena H. , Wedderburn L. R. , Chinoy H. , Betteridge Z. E. , North J. , Ollier W. E. R. , Cooper R. G. , Oddis C. V. , Ramanan A. V. , Davidson J. E. , McHugh N. J.
Published: May 2009

Objective

The identification of novel autoantibodies in juvenile dermatomyositis (DM) may have etiologic and clinical implications. The aim of this study was to describe autoantibodies to a 140‐kd protein in children recruited to the Juvenile DM National Registry and Repository for UK and Ireland.

Methods

Clinical data and sera were collected from children with juvenile myositis. Sera that recognized a 140‐kd protein by immunoprecipitation were identified. The identity of the p140 autoantigen was investigated by immunoprecipitation/immunodepletion, using commercial monoclonal antibodies to NXP‐2, reference anti‐p140, and anti‐p155/140, the other autoantibody recently described in juvenile DM. DNA samples from 100 Caucasian children with myositis were genotyped for HLA class II haplotype associations and compared with those from 864 randomly selected UK Caucasian control subjects.

Results

Sera from 37 (23%) of 162 patients with juvenile myositis were positive for anti‐p140 autoantibodies, which were detected exclusively in patients with juvenile DM and not in patients with juvenile DM–overlap syndrome or control subjects. No anti‐p140 antibody–positive patients were positive for other recognized autoantibodies. Immunodepletion suggested that the identity of p140 was consistent with NXP‐2 (the previously identified MJ autoantigen). In children with anti‐p140 antibodies, the association with calcinosis was significant compared with the rest of the cohort (corrected P < 0.005, odds ratio 7.0, 95% confidence interval 3.0–16.1). The clinical features of patients with anti‐p140 autoantibodies were different from those of children with anti‐p155/140 autoantibodies. The presence of HLA–DRB1*08 was a possible risk factor for anti‐p140 autoantibody positivity.

Conclusion

This study has established that anti‐p140 autoantibodies represent a major autoantibody subset in juvenile DM. This specificity may identify a further immunogenetic and clinical phenotype within the juvenile myositis spectrum that includes an association with calcinosis.
Decrease in glomerulonephritis and Th1‐associated autoantibody production after progesterone treatment in NZB/NZW mice
Authors: Hughes Grant C. , Martin David , Zhang Kang , Hudkins Kelly L. , Alpers Charles E. , Clark Edward A. , Elkon Keith B.
Published: May 2009

Objective

While estrogen treatment exacerbates disease in models of systemic lupus erythematosus (SLE), the effects of progesterone are unclear. This study was undertaken to assess the effects of continuous progesterone treatment on autoantibody production and spontaneous glomerulonephritis (GN) in a mouse model of SLE.

Methods

Female (NZB × NZW)F1 (NZB/NZW) mice were treated with vehicle, 2 mg of depot medroxyprogesterone acetate (DMPA), or 10 mg of DMPA every 6 weeks. Survival, proteinuria, and serum anti–double‐stranded DNA (anti‐dsDNA) levels were monitored. At 39 weeks of age, kidneys were analyzed for abnormalities and glomerular accumulation of IgG subclasses and C3. Spleen leukocyte subsets were also analyzed.

Results

DMPA treatment reduced mortality in a dose‐dependent manner in association with reduced proteinuria and glomerular damage. High‐dose DMPA treatment resulted in a reduction of total serum IgG and IgG2a anti‐dsDNA antibody levels, whereas IgG1 anti‐dsDNA antibody levels were modestly increased. High‐dose DMPA reduced glomerular accumulation of IgG1, IgG2a, IgG3, and complement, while low‐dose DMPA decreased glomerular IgG2a and IgG3 levels compared with vehicle treatment.

Conclusion

Our findings indicate that treatment of premorbid female NZB/NZW mice with DMPA reduces mortality and attenuates spontaneous GN, likely through multiple mechanisms, including altered ratios of protective Th2‐related IgG antibodies versus nephritogenic Th1‐related IgG autoantibodies. Thus, estrogen and progesterone may have disparate effects on lupus autoimmunity, lending new significance to observed hormonal imbalances in patients with SLE. These data also suggest that treatment of SLE patients with DMPA may have therapeutic benefit.
HLA–B27–restricted antigen presentation by human chondrocytes to CD8+ T cells: Potential contribution to local immunopathologic processes in ankylosing spondylitis
Authors: Kuhne Maren , Erben Ulrike , Schulze‐Tanzil Gundula , Köhler Dorothee , Wu Peihua , Richter F. Jan , John Thilo , Radbruch Andreas , Sieper Joachim , Appel Heiner
Published: May 2009

Objective

Analysis of the histopathologic features of hip arthritis in patients with ankylosing spondylitis (AS) has revealed accumulation of infiltrating mononuclear cells in the bone end plate and presence of hyaline articular cartilage that is not found in areas of total cartilage destruction. This study was undertaken to assess whether chondrocytes attract lymphocytes and whether cartilage chondrocytes from patients with AS have the potential to directly stimulate T cells in an HLA‐restricted manner.

Methods

Human HLA–B27+ T cell lines, specific for the Epstein‐Barr virus–derived peptide EBNA258–266, and autologous chondrocytes, serving as nonprofessional antigen‐presenting cells (APCs), were available for use in a model system to study chondrocyte functions in femoral head joint cartilage of patients with AS. Peptide functionality of cytotoxic T cells was assessed by flow cytometry, and cellular interactions were detected by fluorescence confocal microscopy.

Results

When maintained in an alginate matrix, chondrocytes isolated from the femoral heads of patients with AS constitutively expressed type II collagen and CD80. When pulsed with the EBNA258–266 peptide, autologous chondrocytes functioned as APCs and, specifically, induced interferon‐γ production in CD8+ T cells. In mixed chondrocyte–T cell cultures, cell–cell contacts were dependent on the presence of the EBNA258–266 peptide. T cells adjacent to chondrocytes produced perforin and granzyme B; both molecules were found in focal aggregates, a prerequisite for antigen‐specific lysis of target cells.

Conclusion

Antigen presentation through human chondrocytes allows the stimulation of peptide‐specific CD8+ T cells. These results indicate that human chondrocytes can act as nonprofessional APCs, and suggest that there is an interferon‐γ–triggered autocrine loop of immune cell–mediated chondrocyte activation in the already inflamed environment. Thus, local HLA‐dependent activation of peptide‐specific cytotoxic CD8+ T cells by chondrocytes might contribute to inflammatory processes in the spondylarthritides.
Intervention of an inflammation amplifier, triggering receptor expressed on myeloid cells 1, for treatment of autoimmune arthritis
Authors: Murakami Yousuke , Akahoshi Tohru , Aoki Naoko , Toyomoto Masayasu , Miyasaka Nobuyuki , Kohsaka Hitoshi
Published: May 2009

Objective

Triggering receptor expressed on myeloid cells 1 (TREM‐1) is inducible on monocyte/macrophages and neutrophils and accelerates tissue destruction by propagating inflammatory responses in disease related to bacterial infections. Its blockade rescues the hosts in murine models of sepsis, to clear the bacteria without impairing the host defense. The aim of this study was to investigate the involvement of TREM‐1 in an autoimmune, noninfectious disease.

Methods

Synovial tissue specimens from the joints of patients with rheumatoid arthritis (RA) and the joints of mice with collagen‐induced arthritis (CIA) were examined for TREM‐1 expression, using flow cytometric analysis. Expression of TREM‐1 on macrophages was induced by lipopolysaccharide, with or without a cyclooxygenase inhibitor. Rheumatoid synovial cells were stimulated with agonistic anti–TREM‐1 antibodies. Recombinant adenovirus encoding the extracellular domain of TREM‐1 fused with IgG‐Fc (AxCATREM‐1 Ig) or synthetic TREM‐1 antagonistic peptides were injected to treat CIA, and the clinical manifestations of the antigen‐specific T cell and B cell responses were evaluated.

Results

TREM‐1 was expressed on CD14+ cells in rheumatoid synovial tissue and synovial macrophages from mice with CIA. Unlike murine macrophages, human monocyte/macrophages did not depend on prostaglandin E2 for up‐regulation of TREM‐1. Agonistic anti–TREM‐1 antibodies promoted tumor necrosis factor α production from rheumatoid synovial cells. Blockade of TREM‐1 using AxCATREM‐1 Ig and antagonistic peptides ameliorated CIA without affecting the serum levels of anti–type II collagen antibodies or the proliferative responses of splenocytes to type II collagen.

Conclusion

TREM‐1 ligation contributes to the pathology of autoimmune arthritis. The results of this study implied that blockade of TREM‐1 could be a new approach to rheumatic diseases that is safer than the presently available immunosuppressive treatments.
Impaired differentiation and cytotoxicity of natural killer cells in systemic lupus erythematosus
Authors: Park Yong‐Wook , Kee Seung‐Jung , Cho Young‐Nan , Lee Eun‐Hee , Lee Hwa‐Youn , Kim Eun‐Mi , Shin Min‐Ho , Park Jeong‐Jin , Kim Tae‐Jong , Lee Shin‐Seok , Yoo Dae‐Hyun , Kang Hyung‐Sik
Published: May 2009

Objective

To determine the cytotoxicity of natural killer (NK) cells and the level of differentiation of hematopoietic stem cells (HSCs) into NK cells in systemic lupus erythematosus (SLE).

Methods

Patients with SLE (n = 108), rheumatoid arthritis (RA; n = 90), Behçet's disease (n = 39), or ankylosing spondylitis (n = 41) and healthy control subjects (n = 173) were enrolled in the study. NK cell levels, NK cell cytotoxicities, and lymphokine‐activated killer (LAK) activities against K562 cells were measured by flow cytometry. Gene expression was assessed by reverse transcription–polymerase chain reaction. NK cells were differentiated from peripheral blood and bone marrow HSCs in vitro.

Results

Percentages and absolute numbers of NK cells, cytotoxicities, and LAK activities were significantly lower in the peripheral blood of SLE and RA patients than in that of healthy controls. In particular, this NK cell deficiency was more prominent in patients with lupus nephritis and those with thrombocytopenia. Notably, purified NK cells derived from SLE patients, but not RA patients, were found to have lower cytotoxicities and LAK activities than those from healthy controls. This defect of NK cells in SLE patients was found to be related to lower numbers of NK precursors and to the down‐regulation of perforin and granzyme in NK cells. The proliferative capacity of HSCs, the percentages of NK cells differentiated from HSCs, and NK cell cytotoxicities were significantly lower in SLE patients.

Conclusion

In SLE patients, circulating levels of NK cells were diminished and their cytotoxicities were impaired. Furthermore, the differentiation of HSCs into NK cells was found to be defective. These abnormalities possibly contribute to immune system dysregulation in SLE.