bluuebunny/crossref_metadata_2025 huggingface dataset:
Different‐sized duplications of Xq28, including MECP2, in three males with mental retardation, absent or delayed speech, and recurrent infections
Authors: Smyk M. , Obersztyn E. , Nowakowska B. , Nawara M. , Cheung S.W. , Mazurczak T. , Stankiewicz P. , Bocian E.
Published: December 2007

In XY males, duplication of any part of the X chromosome except the pseudoautosomal region leads to functional disomy of the corresponding genes. We describe three unrelated male patients with mental retardation (MR), absent or delayed speech, and recurrent infections. Using high‐resolution comparative genomic hybridization (HR‐CGH), whole genome array comparative genomic hybridization (array CGH), fluorescent in situ hybridization (FISH), and multiplex ligation probe amplification (MLPA), we have identified and characterized two different unbalanced Xq27.3‐qter translocations on the Y chromosome (approx. 9 and 12 Mb in size) and one submicroscopic interstitial duplication (approx. 0.3–1.3 Mb) involving the MECP2 gene. Despite the differences in size of the duplicated segments, the patients share a clinical phenotype that overlaps with the features described in patients with MECP2 duplication. Our data confirm previous observations that MECP2 is the most important dosage‐sensitive gene responsible for neurologic development in patients with duplications on the distal part of chromosome Xq. © 2007 Wiley‐Liss, Inc.
Impact of the Fragile X mental retardation 1 (FMR1) gene premutation on neuropsychiatric functioning in adult males without fragile X‐associated Tremor/Ataxia syndrome: A controlled study
Authors: Kogan Cary S. , Turk Jeremy , Hagerman Randi J. , Cornish Kim M.
Published: December 2007

Fragile X Syndrome is the most common heritable form of mental retardation caused by silencing of the FMR1 gene, which arises from intergenerational trinucleotide repeat expansion leading to full mutation. An intermediary carrier condition, known as the premutation, is characterized by expansion up to 200 repeats without concomitant gene silencing. This prevalent allelic variant was initially thought to be free of phenotypic effects. However, recent reports have identified a degenerative disease, Fragile X‐associated Tremor/Ataxia Syndrome (FXTAS) in older men as well as premature ovarian failure in women. Previously reports are inconsistent regarding the neuropsychiatric phenotype associated with premutation due to small sample sizes, ascertainment bias, lack of adequate control groups, administration of measures with poor psychometric properties, and the confounding effects of FXTAS. We addressed these problems by conducting a controlled study of male carriers (n = 40) of the premutation without manifest symptoms of FXTAS, comparing their responses on specific, reliable, and valid measures of neuropsychiatric functioning to those of individuals with shared family environment (n = 22) and non‐carrier comparison males (n = 43). Multivariate analyses revealed that the premutation confers significant risk for working memory difficulties, an associated feature of Attention‐Deficit Disorder. Furthermore, both the family controls and men with premutation exhibited higher rates of Alcohol Abuse as compared to non‐carrier control men. These findings highlight the importance of recognizing the distinct phenotypic outcomes that characterize the Fragile X premutation and the subtle risk factors that can act as precursors to more significant psychiatric impairment. © 2007 Wiley‐Liss, Inc.
Preparation of PFSA‐PVA/PSf hollow fiber membrane for IPA/H2O pervaporation process
Authors: Lang Wan‐Zhong , Tong Wei , Xu Zhen‐Liang
Published: December 2007

Using Na+form of perfluorosulfonic acid (PFSA) and poly(vinyl alcohol) (PVA) as coating materials, polysulfone (PSf) hollow fiber ultrafiltration membrane as a substrate membrane, PFSA‐PVA/PSf hollow fiber composite membrane was fabricated by dip‐coating method. The membranes were post‐treated by two methods of heat treatment and by both heat treatment and chemical crosslinking. Maleic anhydride (MAC) aqueous solution was used as chemical crosslinking agent using 0.5 wt % H2SO4as a catalyst. PFSA‐PVA/PSf hollow fiber composite membranes were used for the pervaporation (PV) separation of isopropanol (IPA)/H2O mixture. Based on the experimental results, PFSA‐PVA/PSf hollow fiber composite membrane is suitable for the PV dehydration of IPA/H2O solution. With the increment of heat treatment temperature, the separation factor increased and the total permeation flux decreased. The addition of PVA in PFSA‐PVA coating solution was favorable for the improvement of the separation factor of the composite membranes post‐treated by heat treatment. Compared with the membranes by heat treatment, the separation factors of the composite membranes post‐treated by both heat treatment and chemical crosslinking were evidently improved and reached to be about 520 for 95/5 IPA/water. The membranes post‐treated by heat had some cracks which disappeared after chemical crosslinking for a proper time. Effects of feed temperature on PV performance had some differences for the membranes with different composition of coating layer. The composite membranes with the higher mass fraction of PVA in PFSA‐PVA coating solution were more sensitive to temperature. It was concluded that the proper preparation conditions for the composite membranes were as follows: firstly, heated at 160°C for 1 h, then chemical crosslinking at 40°C for 3 h in 4% MAC aqueous solution. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Influence of fillers on the properties of a phenolic resin cured in acidic medium
Authors: Laza J. M. , Alonso J. , Vilas J. L. , Rodríguez M. , León L. M. , Gondra K. , Ballestero J.
Published: December 2007

The curing behavior of a phenolic resol resin in the presence of p‐toluensulphonic acid is reported herein. The gel time of different systems has been determined by thermal scanning rheometry. Thermal and mechanical properties of the resin have been modified by the addition of varying amounts of fillers, talc, and kaolin. dynamic mechanical thermal analysis is used to determine the mechanical properties of the systems and the influence of the fillers and the postcuring. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
The influence of in situ modification of silica on filler network and dynamic mechanical properties of silica‐filled solution styrene–butadiene rubber
Authors: Wu You‐Ping , Zhao Qing‐Song , Zhao Su‐He , Zhang Li‐Qun
Published: December 2007

The influence of in situ modification of silica with bis‐(3‐(triethoxysilyl)‐propyl)‐tetrasulfide (TESPT) on filler network in silica filled solution SBR compound was investigated. In situ modification greatly increased the bound rubber content. TEM observation of silica gel showed that bridging and interlocking of absorbed chains on the surface of silica particles formed the filler network. Rubber processing analyzer (RPA) was used to characterize the filler network and interaction between silica and rubber by strain and temperature sweeps. In situ modification improved the dispersion of silica, and in the meantime, the chemical bonds were formed between silica and rubber, which conferred the stability of silica dispersion during the processing. Compared to the compound without in situ modification, the compound with in situ modification of silica exhibited higher tan δ at low strains and lower tan δ at high strains, which can be explained in terms of filler network in the compounds. After in situ modification, DMTA results showed silica‐filled SSBR vulcanizate exhibited higher tan δ in the temperature range of −30 to 10°C, and RPA results showed that it had lower tan δ at 60°C when the strain was more than 3%. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Thermal gradient solid state forming of polypropylene
Authors: Lo J. C. W. , Shinozaki D. M.
Published: December 2007

The near surface region of polypropylene was hardened in a forming process, which involved a large shear strain in a strong thermal gradient. The optimal processing conditions were estimated by modeling the temperature distribution in the deformation zone. Microindentation testing was used to characterize the corresponding depth‐dependent mechanical properties. The mechanical gradient, which developed after forming, was consistent with the observed variation in microstrucfture. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Toughening of an epoxy resin with an isocyanate‐terminated polyether
Authors: Soares Bluma G. , Gonçalez Viviane , Galimberti Rurik , Sirqueira Alex S. , Barcia Fabio L. , Simão Renata A.
Published: December 2007

A low‐molar‐mass, hydroxyl‐terminated polyether [polypropylene glycol/poly(ethylene glycol) copolymer (POPE)] was functionalized with isocyanate groups and used to improve the impact resistance of a diglycidyl ether of bisphenol A based epoxy resin cured with triethylene tetramine (TETA). The effect of polyether‐based modifiers (with and without NCO groups) on the curing rate of the epoxy/TETA system was investigated with rheological techniques. The NCO‐functionalized polyether reduced the gel time, and this indicated an accelerating effect of the curing process. In addition, a significant improvement in the impact resistance was observed with only a slightly detrimental effect on the stiffness and mechanical strength. Scanning electron microscopy of the corresponding epoxy network revealed a homogeneous morphology with no phase separation. The miscibility of NCO‐modified POPE and the epoxy resin was also confirmed with atomic force microscopy. The glass‐transition temperature of the epoxy networks was also investigated with dynamic mechanical techniques. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Synthesis and characterization of polyethylene modified through phase‐transfer‐catalyzed graft copolymerization
Authors: Kaur Inderjeet , Dogra Ramesh , Kaur Simrat , Deepika N.
Published: December 2007

In an effort to impart biodegradability, polyethylene (PE) was modified through the graft copolymerization of vinyl monomers such as acrylamide (AAm) and acrylic acid (AAc) by a phase‐transfer‐catalyst method. The grafting percentage of AAm and AAc for PE was found to be dependent on the dibenzoyl peroxide concentration, monomer concentration, time, temperature, and concentration of the phase‐transfer catalyst. Some AAm‐ and AAc‐grafted PE samples were prepared by chemical, UV, and γ‐radiation methods. The biodegradation of samples of PE, polyethylene‐g‐polyacrylamide, and polyethylene‐g‐poly(acrylic acid) prepared by all these methods was studied. The weight loss of the samples over a period of time was observed with soil‐burial tests. The grafted samples prepared by the phase‐transfer‐catalyst method showed better biodegradation results than those prepared by other methods of grafting. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
The study of melt grafting mechanism of acrylic acid and butyl acrylate onto low density polyethylene and its application as internal plasticizer
Authors: Ding Shenglong , Liu Mingzhu , Fang Haibin
Published: December 2007

Melt grafting of acrylic acid (AA) and butyl acrylate (BA) (equal molar ratios) onto low‐density polyethylene (LDPE) was carried out in Haake internal mixter by free radical grafting copolymerization. The graft degree of AA and BA in the grafted LDPE (LDPE‐g‐(AA+BA)) was determined by FTIR. The influences of initiator on the graft degree of AA and BA, melt flow rate (MFR), and gel content were investigated, and the optimum conditions were obtained. The successive self‐nucleation/annealing (SSA) thermal fraction method was used to characterize the molecular structure and polydispersity of LDPE‐g‐(AA+BA) with various graft degrees. The effects of thermal fraction parameters on fraction of LDPE‐g‐(AA+BA) were investigated. On the basis of the results of SSA, the grafting reaction mechanism of AA and BA onto LDPE was proposed, i.e., grafting reaction preferentially occurred on the tertiary carbons of LDPE. The grafted LDPE possessed suitable reactivity and rheological property. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Characterization of polyaniline via pyrolysis mass spectrometry
Authors: Hacaloglu Jale , Argin Emir , Kücükyavuz Zühal
Published: December 2007

In this work, direct insertion probe pyrolysis mass spectrometry technique was applied to investigate the thermal and the structural characteristics of electrochemically prepared HCl and HNO3‐doped polyaniline (PANI) films. It has been determined that the thermal degradation of both samples showed three main thermal degradation stages. The first stage around 50–60°C was associated with evolution of solvent and low‐molecular‐weight species adsorbed on the polymer, the second stage just above 150°C was attributed to evolution of dopant‐based products, and the final degradation stage at moderate and elevated temperatures was associated with evolution of degradation products of the polymer. Chlorination and nitrolysis of aniline during the electrochemical polymerization were detected. Extent of substitution increased as the electrolysis period was increased. Furthermore, for the HNO3‐doped PANI, the evolution of CO2 at elevated temperatures confirmed oxidation of the polymer film during electrolysis. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Preparation and characterization of high‐impact polystyrene using different types of polybutadiene
Authors: Coutinho F. M. B. , Costa M. P. M. , Guimarães M. J. O. C. , Soares B. G.
Published: December 2007

The mechanical, morphological, and rheological properties of polymer blends based on polystyrene (PS) and three different types of polybutadiene (PB) were studied. The polymer blends containing 20% of PB were processed in a Haake mixer at 180°C and 60 rpm for 6 min. The materials exhibited impact strength superior to that of the PS. An increase was observed in the impact strength of 138, 208, and 823%, when low‐cis polybutadiene (PBl), high‐cis polybutadiene (PBh), and styrene–butadiene block copolymer (PBco), were respectively used. The materials presented dispersed morphology with polybutadiene domains, with sizes inferior to 1 μm, randomly distributed in the PS matrix. The viscous and storage moduli increased as the applied frequency increased. The flow activation energy, calculated by Arrhenius equation, varied from 34 to 71 kJ/mol. In the rheological experiments all polymer blends presented pseudoplastic behavior, showing decreasing viscosities as the shear rate increased. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Compatibilization efficiency of styrene‐butadiene block copolymers as a function of their block number
Authors: Vranješ Nina , Lednický František , Kotek Jiří , Baldrian Josef , Rek Vesna , Fortelný Ivan , Horák Zdeněk
Published: December 2007

Effect of block number in linear styrene‐butadiene (SB) block copolymers (BCs) on their compatibilization efficiency in blending polystyrene (PS) with polybutadiene (PB) was studied. Di‐, tri‐, or pentablocks of SB copolymers as well as their combinations were blended with the mentioned homopolymers; supramolecular structure determined by small angle X‐ray scattering method (SAXS), morphology using scanning electron microscopy (SEM) combined with image analysis (IA), and stress transfer characteristics of the blends were chosen as criteria of compatibilization efficiency of the copolymers used. It was proved that the addition of SB BCs led to remarkably finer phase structure and substantially higher toughness of PS/PB blends. Triblock copolymer showed to be the compatibilizer with higher efficiency than diblock, pentablock, and the di/triblock copolymer mixture. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Thermal stability and decomposition mechanism of poly(p‐acryloyloxybenzoic acid and poly (p‐methacryloyloxybenzoic acid) and their graft copolymers with polypropylene, Part II
Authors: Çetin S. , Tinçer T.
Published: December 2007

Thermal stability and decomposition mechanism of poly(p‐acryloyloxybenzoic) acid (PABA), p‐methacryloyloxybenzoic acid (PMBA), and their graft coproducts of PP were studied by differential scanning calorimetry, direct pyrolysis mass spectrometry, and TG/IR system, combined thermogravimetric analyzer, and FTIR spectrometer. The homopolymers and corresponding grafts were found to be stable in nitrogen atmosphere but started to decompose under atmospheric conditions when heated above 230°C. PABA and PAPA‐g‐PP showed a better thermal stability compared to the other polymer. The degradation proceeded predominantly by decomposition of side groups giving phenol, benzoic acid, hydroxybenzoic acid, carboxylic and carbonyl groups, and by decomposition of phenol into cyclodiene mainly. It was also seen that the degradation path did not greatly changed whether the PABA or PMBA were homopolymers or grafted onto PP but the induction temperature of grafted polymers was seen at some 10–20°C higher. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Chemoenzymatic synthesis, characterization, and controlled release of functional polymeric prodrugs with acyclovir as pendant
Authors: Li Xia , Wu Qi , Zhang Fu , Lin Xian‐Fu
Published: December 2007

An efficient protocol for the synthesis of functional polymeric prodrugs of acyclovir with variable copolymer composition and potential liver‐targeting delivery was achieved by combining enzymatic selective synthesis of polymerizable acyclovir derivatives with radical copolymerization of properly selected comonomers. Vinyl D‐galactose ester (VAG), acrylic acid (AA), and methyl methacrylate (MMA) were chosen as comonomers and three novel polymeric prodrugs with acyclovir as pendant were synthesized using 2,2′‐azo‐bis‐iso‐butyronitrile (AIBN) as initiator in N,N‐dimethylformamide (DMF). The resulting polymers were characterized by FTIR, NMR, and GPC. The influence of the concentration of initiator and the molar ratio of comonomers on the polymerization was investigated. In vitro drug release studies showed that acyclovir could be released from poly(2‐N‐vinylsebacyl‐acyclovir‐co‐methyl methacrylate) (poly(VSA‐co‐MMA)), and the total released acyclovir after 7 days in buffer solution at pH 1.2 and 7.4 was ∼ 35% and 29%, respectively. Also, homopolymers of vinyl acyclovir derivatives with high drug payload (>50 wt %) were obtained and characterized by the same methods. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Studies of adsorption of alkaline trypsin by poly(methacrylic acid) brushes on chitosan membranes
Authors: Bayramoğlu Gülay , Erdogan Hakan , Arica M. Yakup
Published: December 2007

Poly(methacrylic acid)‐grafted chitosan membranes (chitosan‐g‐poly(MAA)) were prepared in two sequential steps: in the first step, chitosan membranes were prepared by phase‐inversion technique and then epichlorohydrin was used as crosslinking agent to increase its chemical stability in acidic media; in the second step, the graftcopolymerization of methacrylic acid onto the chitosan membranes was initiated by ammonium persulfate (APS) under nitrogen atmosphere. The chitosan‐g‐poly(MAA) membranes were first used as an ion‐exchange support for adsorption of trypsin from aqueous solution. The influence of pH, equilibrium time, ionic strength, and initial trypsin concentration on the adsorption capacity of the chitosan‐g‐poly(MAA) membranes have been investigated in a batch system. Maximum trypsin adsorption onto chitosan‐g‐poly(MAA) membrane was found to be 92.86 mg mL−1 at pH 7.0. The experimental equilibrium data obtained for trypsin adsorption onto chitosan‐g‐poly(MAA) membranes fitted well to the Langmuir isotherm model. The adsorption data was analyzed using the first‐ and second‐order kinetic models, and the experimental data was well described by the second‐order equation. More than 97% of the adsorbed trypsin was desorbed using glutamic acid solution (0.5M, pH 4.0). In addition, the chitosan‐g‐ poly(MAA) membrane prepared in this work showed promising potential for various biotechnological applications. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Differential expression of CYP6A5 and CYP6A5v2 in pyrethroid‐resistant house flies, Musca domestica
Authors: Zhu Fang , Liu Nannan
Published: December 2007

Two cytochrome P450 alleles, CYP6A5 and CYP6A5v2, were isolated from a pyrethroid‐resistant house fly stain, ALHF. The two alleles shared 98% similarity in amino acid sequence. To understand the importance of these two alleles in resistance and examine the expression profile of the two alleles between resistant and susceptible strains, quantitative real‐time PCR (qRT‐PCR) was performed and compared with the Northern blot analysis. We found that qRT‐PCR was an efficient method to characterize the expression profiles between these two sequence‐closely‐related P450 genes between resistant and susceptible houses flies. One of them, CYP6A5v2, was constitutively overexpressed in ALHF house flies compared with susceptible house fly strains. Moreover, this gene was predominately expressed in the abdominal tissues of ALHF, in which the primary detoxification organs of insects are located. However, there was no significant difference in the expression of CYP6A5 between ALHF and susceptible house flies. The genetic linkage analysis was conducted to determine the possible link between the constitutively overexpressed CYP6A5v2 and insecticide resistance. CYP6A5v2 was mapped on autosome 5, which is correlated with the linkage of resistance in ALHF. Taken together, the study suggests the importance of CYP6A5v2 in increasing metabolic detoxification of insecticides in ALHF. The distinct expression of CYP6A5 and CYP6A5v2 in resistant and susceptible house flies implies the functional difference of theses two genes in house flies and suggests that they are two recently diverged P450 genes presented in a single organism. Arch. Insect Biochem. Physiol. 2007. © 2007 Wiley‐Liss, Inc.
cDNA cloning, characterization, and developmental expression of the 20S proteasome α5 subunit in the Mediterranean fruit fly Ceratitis capitata
Authors: Verras Meletios , Gourzi Polyxeni , Kalosaka Katerina , Zacharopoulou Antigone , Mintzas Anastassios C.
Published: December 2007

In the present study, we report the cDNA cloning, characterization, and developmental expression of the 20S proteasome α5 subunit from the Mediterranean fruit fly Ceratitis capitata (medfly). Using an RT‐PCR fragment that corresponds to the amino‐terminal region of the Drosophila melanogaster 20S proteasome α5 subunit, we isolated a 987‐bp cDNA that encodes the complete coding region of the medfly ortholog, which was named CcPSMA5. CcPSMA5 consists of 241 amino acids and has a predicted molecular weight of 26.4 kDa and pI 4.75. Comparison of the CcPSMA5 amino acid sequence with the sequences of all known 20S proteasome α5 subunits from different organisms indicated that the medfly 20S proteasome α5 subunit has the strongest homology to that of Drosophila. In situ hybridization showed that the CcPSMA5 gene is mapped in the region 44B of chromosome 4. Northern blot hybridization analysis showed that the CcPSMA5 mRNA has a size of approximately 1.2 kb. High levels of the CcPSMA5 mRNA were detected in freshly laid eggs, indicating that they were maternally deposited. The mRNA expression pattern during medfly development suggests that the CcPSMA5 gene is upregulated before mid‐embryogenesis and at the onset of metamorphosis. Arch. Insect Biochem. Physiol. © 2007 Wiley‐Liss, Inc.
Novel cytochrome P450s, CYP6BB1 and CYP6P10, from the salt marsh mosquito Aedes sollicitans (Walker) (Diptera: Culicidae)
Authors: Huang Shaoming , Sun Debin , Brattsten L. B.
Published: December 2007

Based on the conserved heme‐binding region and the charge pair consensus of insect cytochrome P450s, two novel full‐length P450 cDNAs, CYP6BB1 and CYP6P10, were cloned from the salt marsh mosquito Aedes sollicitans (Walker). CYP6BB1 and CYP6P10 had open reading frames of 1,518 and 1,521 nucleotides encoding 506 and 507 amino acid residue proteins, respectively. Several alleles with amino acid substitutions were found both in CYP6BB1 and CYP6P10. The deduced proteins are typical microsomal P450s sharing signature sequences with other insect CYP6 P450s. Sequence analysis showed that both CYP6BB1 and CYP6P10 shared highest sequence identities with P450 CYP6P4, 56% and 65%, respectively. Phylogenetic analysis showed both CYP6BB1 and CYP6P10 were grouped into the clade containing several P450s from subfamily CYP6P. Real‐time RT‐PCR analysis showed CYP6BB1 but not CYP6P10 transcription in females was significantly increased 24 h after a blood meal. Neither CYP6BB1 nor CYP6P10 were life stage or gender specific. Protein expression experiments are needed to determine the functions of these proteins. Arch. Insect Biochem. Physiol. 2007. © 2007 Wiley‐Liss, Inc.
Arthritogenic antibodies specific for a major type II collagen triple‐helical epitope bind and destabilize cartilage independent of inflammation
Authors: Nandakumar Kutty Selva , Bajtner Estelle , Hill Leigh , Böhm Beate , Rowley Merrill J. , Burkhardt Harald , Holmdahl Rikard
Published: December 2007

Objective

To investigate the significance and pathogenic potential of a highly conserved major type II collagen triple‐helical epitope–specific antibody (U1; amino acids 494–504) in vivo and in vitro in patients with early rheumatoid arthritis (RA) and in experimental animal models of collagen‐induced arthritis (CIA).

Methods

U1‐specific antibodies in sera from patients with early RA (with or without joint erosions) were analyzed. Disease progression in the CIA models in mice and rats with anti‐U1 antibodies was compared. The pathogenicity of binding of monoclonal antibodies (mAb) UL1 and CIIF4 to the U1 epitope and the F4 epitope (aa 926–936), respectively, was compared in vivo and on chondrocyte cultures and preformed cartilage in vitro, using Fourier transform infrared microspectroscopy analysis. In addition, UL1‐induced proteoglycan depletion in vivo in the presence and absence of the complement factor C5 was analyzed.

Results

Increased levels of U1 antibodies were observed in patients with early RA, especially in association with joint erosions. A significant correlation of U1‐specific antibodies with disease progression was found in rats and mice with CIA. UL1 mAb induced, whereas CIIF4 mAb inhibited, the progression of arthritis. Similarly, UL1, but not CIIF4, impaired matrix synthesis on chondrocyte cultures and adversely affected preformed cartilage. Furthermore, UL1 induced significant proteoglycan depletion in vivo 3 days after injection, even in the absence of C5.

Conclusion

Antibody epitope specificity contributes significantly to the development of arthritis, and the early pathogenic events operate independent of inflammation both in vitro and in vivo.
Abnormal tumor necrosis factor receptor I cell surface expression and NF‐κB activation in tumor necrosis factor receptor–associated periodic syndrome
Authors: Nedjai Belinda , Hitman Graham A. , Yousaf Nasim , Chernajovsky Yuti , Stjernberg‐Salmela Susanna , Pettersson Tom , Ranki Annamari , Hawkins Philip N. , Arkwright Peter D. , McDermott Michael F. , Turner Mark D.
Published: December 2007

Objective

Tumor necrosis factor receptor–associated periodic syndrome (TRAPS) is an autosomal‐dominant autoinflammatory condition caused by mutations in the TNFRSF1A gene. The cellular mechanisms by which mutations in this gene trigger inflammation are currently unclear. Because NF‐κB is the major intracellular signaling component inducing secretion of proinflammatory cytokines, we sought to determine whether differences in the clinical phenotype of patients with TRAPS may be attributable to variable effects of TNFRSF1A mutations on TNFRI expression, localization, or NF‐κB activity.

Methods

Peripheral blood mononuclear cells were obtained from patients (following informed consent), and cellular nuclear and cytosolic fractions were generated by subcellular fractionation. Localization of IκBα and NF‐κB was determined by Western blotting of the resultant fractions. NF‐κB subunit activity was determined by enzyme‐linked immunosorbent assay analysis and confirmed by electrophoretic mobility shift assay. Subcellular localization of TNFRI was determined by immunofluorescence confocal microscopy or by immunoblotting following affinity isolation of plasma membrane by subcellular fractionation.

Results

Cells from patients with the fully penetrant C73R mutation had marked activation of the proinflammatory p65 subunit of NF‐κB. In contrast, cells from patients with the low‐penetrant R92Q mutation displayed high levels of DNA binding by the p50 subunit, an interaction previously linked to repression of inflammation. Interestingly, although cells from patients with the C73R mutation have no TNFRI shedding defect, there was nonetheless an unusually high concentration of functional TNFRI at the plasma membrane.

Conclusion

High levels of TNFRI at the cell surface in patients with the C73R mutation hypersensitizes cells to stimulation by TNF, leading to increased NF‐κB p65 subunit activation and an exaggerated proinflammatory response.
A biomarker‐based mathematical model to predict bone‐forming potency of human synovial and periosteal mesenchymal stem cells
Authors: De Bari Cosimo , Dell'Accio Francesco , Karystinou Alexandra , Guillot Pascale V. , Fisk Nicholas M. , Jones Elena A. , McGonagle Dennis , Khan Ilyas M. , Archer Charles W. , Mitsiadis Thimios A. , Donaldson Ana Nora , Luyten Frank P. , Pitzalis Costantino
Published: December 2007

Objective

To develop a biomarker‐based model to predict osteogenic potency of human mesenchymal stem cells (MSCs) from synovial membrane and periosteum.

Methods

MSC populations were derived from adult synovium and periosteum. Phenotype analysis was performed by fluorescence‐activated cell sorting and real‐time reverse transcriptase–polymerase chain reaction (RT‐PCR). Telomere lengths were determined by Southern blot analysis. In vitro osteogenesis was assessed quantitatively by measurements of alkaline phosphatase activity and calcium deposits. To investigate bone formation in vivo, MSCs were seeded onto osteoinductive scaffolds and implanted subcutaneously in nude mice. Bone was assessed by histology, and the human origin investigated by in situ hybridization for human Alu genomic repeats. Quantitation was achieved by histomorphometry and real‐time RT‐PCR for human osteocalcin. Analysis at the single‐cell level was performed with clonal populations obtained by limiting dilution. Multiple regressions were used to explore the incremental predictive value of the markers.

Results

Periosteal MSCs had significantly greater osteogenic potency than did synovial MSCs inherent to the single cell. Bone was largely of human origin in vivo. Within the same tissue type, there was variability between different donors. To identify predictors of osteogenic potency, we measured the expression levels of osteoblast lineage genes in synovial and periosteal clonal MSCs prior to osteogenic treatment. We identified biomarkers that correlated with osteogenic outcome and developed a mathematical model based on type I collagen and osteoprotegerin expression that predicts the bone‐forming potency of MSC preparations, independent of donor‐related variables and tissue source.

Conclusion

Our findings indicate that our quality‐control mathematical model estimates the bone‐forming potency of MSC preparations for bone repair.
Comparison of the clinical efficacy and safety of subcutaneous versus oral administration of methotrexate in patients with active rheumatoid arthritis: Results of a six‐month, multicenter, randomized, double‐blind, controlled, phase IV trial
Authors: Braun J. , Kästner P. , Flaxenberg P. , Währisch J. , Hanke P. , Demary W. , von Hinüber U. , Rockwitz K. , Heitz W. , Pichlmeier U. , Guimbal‐Schmolck C. , Brandt A. ,   MC‐MTX.6/RH Study Group
Published: December 2007

Objective

To compare the efficacy and safety of subcutaneous (SC) versus oral administration of methotrexate (MTX) in patients with active rheumatoid arthritis (RA).

Methods

MTX‐naive patients with active RA (Disease Activity Score in 28 joints ≥4) were eligible for the study if they had not previously taken biologic agents and had not taken disease‐modifying antirheumatic drugs for 2 weeks prior to randomization. Patients were randomly assigned to receive 15 mg/week of MTX either orally (2 7.5‐mg tablets plus a dummy prefilled syringe; n = 187 patients) or SC (prefilled syringe containing 10 mg/ml plus 2 dummy tablets; n = 188 patients) for 24 weeks. At week 16, patients who did not meet the American College of Rheumatology criteria for 20% improvement (ACR20) were switched from 15 mg of oral MTX to 15 mg of SC MTX and from 15 mg of SC MTX to 20 mg of SC MTX for the remaining 8 weeks, still in a blinded manner. The primary outcome was an ACR20 response at 24 weeks.

Results

At week 24, significantly more patients treated with SC MTX than with oral MTX showed ACR20 (78% versus 70%) and ACR70 (41% versus 33%) responses. Patients with a disease duration ≥12 months had even higher ACR20 response rates (89% for SC administration and 63% for oral). In 52 of the ACR20 nonresponders (14%), treatment was switched at week 16. Changing from oral to SC MTX and from 15 mg to 20 mg of SC MTX resulted in 30% and 23% ACR20 response rates, respectively, in these patients. MTX was well tolerated. The rate of adverse events was similar in all groups.

Conclusion

This 6‐month prospective, randomized, controlled trial is the first to examine oral versus SC administration of MTX. We found that SC administration was significantly more effective than oral administration of the same MTX dosage. There was no difference in tolerability.
T cell dependence of chronic destructive murine arthritis induced by repeated local activation of toll‐like receptor–driven pathways: Crucial role of both interleukin‐1β and interleukin‐17
Authors: Joosten Leo A. B. , Abdollahi‐Roodsaz Shahla , Heuvelmans‐Jacobs Marleen , Helsen Monique M. A. , van den Bersselaar Liduine A. M. , Oppers‐Walgreen Birgitte , Koenders Marije I. , van den Berg Wim B.
Published: December 2007

Objective

The pathogenesis of rheumatoid arthritis is often linked to bacterial infections. The present study was undertaken to develop a mouse model of chronic destructive arthritis induced by repeated intraarticular (IA) exposure to bacterial cell wall fragments and to investigate the cytokine dependence of this model.

Methods

Mice that were deficient in various cytokines were injected IA with cell wall fragments of Streptococcus pyogenes on days 0, 7, 14, and 21. The development of chronic destructive arthritis was compared between groups of mice lacking different cytokines, to assess which cytokines were crucial for development of chronic destructive arthritis.

Results

Repeated exposure of a joint to S pyogenes cell wall fragments resulted in the development of chronic destructive arthritis. In mice deficient in recombination‐activating gene 2, streptococcal cell wall (SCW)–directed T cell reactivity was found and chronic arthritis did not develop, implicating T cells in the generation of chronic SCW‐induced arthritis. Interleukin‐17 (IL‐17) receptor–deficient mice showed a reduction of joint destruction in the chronic stage, implicating a detrimental role of the recently discovered IL‐17–producing T helper cells (Th17 cells). IL‐23 expression was apparent during the late stages of arthritis. Joint swelling was no longer dependent on tumor necrosis factor α (TNFα) after the last flare, and pronounced cartilage damage was found after 28 days in TNFα‐deficient mice. In contrast, IL‐1β–deficient mice were fully protected against joint swelling and cartilage and bone destruction during the late stages of disease.

Conclusion

These findings indicate that the TNFα dependence of arthritis is lost during the erosive stage, when Th17 cells become crucial. IL‐1β dependence remains strong, consistent with its pivotal role in the generation of Th17 cells.
Association of serum nitrate and nitrite levels with longitudinal assessments of disease activity and damage in systemic lupus erythematosus and lupus nephritis
Authors: Oates Jim C. , Shaftman Stephanie R. , Self Sally E. , Gilkeson Gary S.
Published: December 2007

Objective

Reactive intermediate production is an essential component of the innate immune response that is induced during disease activity in murine lupus. This study was undertaken to determine whether a marker of systemic nitric oxide (NO) production correlates with prospectively studied disease activity in human systemic lupus erythematosus (SLE) and lupus nephritis patients.

Methods

Eighty‐three SLE patients and 40 control subjects were studied longitudinally. The SLE group included 23 patients with lupus nephritis documented by renal biopsy and 26 with a history of lupus nephritis. During each visit, following a 24‐hour low‐nitrate diet, traditional markers of disease activity and damage were determined. Serum nitrate plus nitrite (NOx) levels were determined by chemiluminescence detection.

Results

NOx levels were higher in SLE patients than in controls during the first visit. In univariate longitudinal analyses, NOx levels were associated with SLE Disease Activity Index scores. In multivariate analyses, NOx levels were associated with serum levels of C3 and creatinine and the urinary protein:creatinine ratio. Among patients with lupus nephritis, those with proliferative lesions had higher NOx levels, and higher NOx levels were associated with accumulation of renal damage and lack of response to therapy.

Conclusion

This is the first study to prospectively demonstrate longitudinal associations between serum NOx levels and markers of SLE and lupus nephritis disease activity. The more pronounced association with proliferative lupus nephritis and with longitudinal response to lupus nephritis therapy provides a rationale for the study of reactive intermediates as biomarkers of disease activity and therapeutic targets in proliferative lupus nephritis.
Interleukin‐1β up‐regulation of Smad7 via NF‐κB activation in human chondrocytes
Authors: Baugé C. , Attia J. , Leclercq S. , Pujol J.‐P. , Galéra P. , Boumédiene K.
Published: December 2007

Objective

We have previously shown that interleukin‐1β (IL‐1β) impairs transforming growth factor β (TGFβ) signaling through TGFβ receptor type II (TGFβRII) down‐regulation and Smad7 up‐regulation. This mechanism could account for the reduced responsiveness of osteoarthritic chondrocytes to TGFβ and the cartilage breakdown linked to this disease. The aim of this study was to investigate the molecular mechanism underlying the IL‐1β–induced stimulation of Smad7 in human articular chondrocytes.

Methods

Human articular chondrocytes were treated with IL‐1β in the presence of TGFβ1, pyrrolidine dithiocarbamate (a repressor of the NF‐κB pathway), or cycloheximide. Then, steady‐state messenger RNA and protein levels were estimated by real‐time reverse transcription–polymerase chain reaction and immunocytology. In addition, transient transfections of p65 expression vector or p65‐targeted short hairpin RNA were performed to define the effect of NF‐κB on Smad7 expression.

Results

TGFβRII overexpression restored the TGFβ response of human articular chondrocytes. However, this effect was transient, implying that a secondary mechanism was responsible for the alteration of the TGFβ response with long‐term exposure to IL‐1β. Moreover, IL‐1β caused a late induction of the inhibitory Smad7. This effect was direct, since it did not require de novo synthesis. In addition, we established, by experiments with gain/loss of function, that the up‐regulation of Smad7 by IL‐1β is mediated through the NF‐κB pathway, especially the p65 subunit.

Conclusion

These findings clarify the regulatory process of IL‐1β on Smad7 expression. Understanding the molecular basis of IL‐1β induction of Smad7 and the reduction of chondrocyte responsiveness to TGFβ provides new insights into the molecular mechanisms of osteoarthritis and may facilitate the identification of novel approaches for its treatment.
Cannabinoid‐mediated antinociception is enhanced in rat osteoarthritic knees
Authors: Schuelert Niklas , McDougall Jason J.
Published: December 2007

Objective

To determine whether local administration of the cannabinoid 1 (CB1) receptor agonist arachidonyl‐2‐chloroethylamide (ACEA) can modulate joint nociception in control rat knee joints and in experimental osteoarthritis (OA).

Methods

OA was induced in male Wistar rats by intraarticular injection of 3 mg of sodium mono‐iodoacetate, with a recovery period of 14 days. Electrophysiologic recordings were made of knee joint primary afferent nerve fibers in response to normal rotation and noxious hyperrotation of the joint both before and after close intraarterial injection of different doses of ACEA.

Results

Local application of the CB1agonist significantly reduced the firing rate of afferent nerve fibers by up to 50% in control knee joints (n = 19) and up to 62% in OA knee joints (n = 29;P< 0.01). Coadministration of the CB1receptor antagonist AM251 or the transient receptor potential vanilloid 1 (TRPV‐1) ion channel antagonist SB366791 significantly reduced the desensitizing effect of ACEA. The CB1receptor antagonist AM251 by itself had no effect in the control joint but significantly increased the firing rate of afferent nerve fibers in the OA joint.

Conclusion

These findings indicate that activation of peripheral CB1receptors reduces the mechanosensitivity of afferent nerve fibers in control and OA knee joints. Blockade of either the CB1receptor or the TRPV‐1 channel significantly reduced the efficacy of ACEA, which suggests that both receptors are involved in cannabinoid‐mediated antinociception. The increased nerve activity observed following CB1receptor antagonism suggests a tonic release of endocannabinoids during OA. As such, peripheral CB1receptors may be important targets in controlling OA pain.
Risks and relative risks of Wegener's granulomatosis among close relatives of patients with the disease
Authors: Knight Ann , Sandin Sven , Askling Johan
Published: December 2007

Objective

The etiology of Wegener's granulomatosis (WG) supposedly involves interplay between genetic susceptibility and environmental triggers. However, little is known about whether WG actually clusters in families. Information on the degree of familial aggregation in WG is of clinical relevance, because patients with WG often want to know whether their diagnosis puts their closest relatives at increased risk of the disease. The aim of this study was to investigate the risk of WG in relatives of patients with WG.

Methods

Using Swedish nationwide registers on morbidity, family structure, and vital status, we compared the occurrence of WG (register‐based plus chart review) among 6,670 first‐degree relatives and 428 spouses of 1,944 Swedish patients with WG with the occurrence among 68,994 first‐degree relatives and 4,812 spouses of 19,655 control subjects from the general population. Relative risks were estimated using the Cox proportional hazards regression model.

Results

Two of the 6,670 first‐degree relatives of patients with WG and 13 of the 68,994 first‐degree relatives of their population controls had WG, resulting in a relative risk of 1.56 (95% confidence interval 0.35–6.90). None of the 428 spouses of patients had WG.

Conclusion

In absolute terms, the occurrence of WG among close biologic and nonbiologic relatives of patients with WG is low. In terms of relative risk, our results provide strong evidence against a pronounced increase in familial risk such as that noted for systemic lupus erythematosus, irritable bowel disease, and multiple sclerosis but are compatible with familial aggregation of a magnitude similar to that for rheumatoid arthritis.
Association of microsomal prostaglandin E synthase 1 deficiency with impaired fracture healing, but not with bone loss or osteoarthritis, in mouse models of skeletal disorders
Authors: Yamakawa Kiyofumi , Kamekura Satoru , Kawamura Naohiro , Saegusa Masatomo , Kamei Daisuke , Murakami Makoto , Kudo Ichiro , Uematsu Satoshi , Akira Shizuo , Chung Ung‐il , Nakamura Kozo , Kawaguchi Hiroshi
Published: December 2007

Objective

Prostaglandin E synthase (PGES) functions as the terminal enzyme in the biosynthesis of prostaglandin E2 (PGE2) and is a potent regulator of bone and cartilage metabolism. Among the 3 isozymes of PGES, microsomal PGES‐1 (mPGES‐1) is known to play the most critical role in the production of PGE2 in pathophysiologic events. This study investigated the roles of mPGES‐1 under normal physiologic and pathophysiologic conditions in the skeletons of mPGES‐1–deficient (mPGES‐1−/−) mice.

Methods

Skeletons of mPGES‐1−/− mice and their wild‐type littermates were compared by radiologic and histologic analyses. Four models of skeletal disorders were created: bone loss induced by ovariectomy, bone loss induced by hind limb unloading, osteoarthritis (OA) induced by instability in the knee joint, and bone fracture by osteotomy at the tibial midshaft. Expression of the PGES enzymes was examined by immunohistochemistry and real‐time reverse transcription–polymerase chain reaction. The cellular mechanism of fracture healing was examined in ex vivo cultures of costal cartilage chondrocytes.

Results

Microsomal PGES‐1−/− mice had unaffected skeletal phenotypes under normal physiologic conditions. In the bone fracture model, fracture healing was impaired by the mPGES‐1 deficiency, with half of the mice remaining in a non–bone union state even after 21 days; normal fracture healing was restored by adenoviral reintroduction of mPGES‐1. The other skeletal disorders were not affected by the mPGES‐1 deficiency. In vivo and ex vivo analyses revealed an impaired proliferation of chondrocytes in cartilage with the mPGES‐1 deficiency, at an early stage of fracture healing.

Conclusion

In these mouse models of skeletal disorders, mPGES‐1 was indispensable for bone repair through chondrocyte proliferation, but was not essential for the skeleton under normal physiologic conditions, nor did it play a role in the pathophysiologic conditions of bone loss due to ovariectomy, bone loss due to unloading, or stress‐induced OA.