bluuebunny/crossref_metadata_2025 huggingface dataset:
Microscopic R2* mapping of reduced brain iron in the Belgrade rat
Authors: Zywicke Holly A. , Van Gelderen Peter , Connor James R. , Burdo Joseph R. , Garrick Michael D. , Dolan Kevin G. , Frank Joseph A. , Bulte Jeff W. M.
Published: October 2002

R2* mapping has recently been used to detect iron overload in patients with movement disorders. We demonstrate here that this technique can also be used to detect reduced brain iron, as in the case of a missense mutation in the iron‐transporting protein divalent metal transporter 1. Surprisingly, we found that the same brain regions are affected (ie, the globus pallidus, substantia nigra, and cerebellar dentate nucleus); this suggests a much more extensive role for these structures in regulating overall brain iron homeostasis. Therefore, for the clinical monitoring of movement disorders for which normal brain iron homeostasis (either overload or reduction) may be implicated, R2* mapping appears to be well‐suited.
Mechanisms of acute cerebral infarctions in patients with middle cerebral artery stenosis: A diffusion‐weighted imaging and microemboli monitoring study
Authors: Wong Ka Sing , Gao Shan , Chan Yu Leung , Hansberg Tjark , Lam Wynnie W. M. , Droste Dirk W. , Kay Richard , Ringelstein E. Bernd
Published: October 2002

Although most therapeutic efforts and experimental stroke models focus on the concept of complete occlusion of the middle cerebral artery as a result of embolism from the carotid artery or cardiac chamber, relatively little is known about the stroke mechanism of intrinsic middle cerebral artery stenosis. Differences in stroke pathophysiology may require different strategies for prevention and treatment. We prospectively studied 30 consecutive acute ischemic stroke patients with middle cerebral artery stenosis detected by transcranial Doppler and magnetic resonance angiography. Patients underwent microembolic signal monitoring by transcranial Doppler and diffusion‐weighted magnetic resonance imaging. Characteristics of acute infarct on diffusion‐weighted magnetic resonance imaging were categorized according to the number (single or multiple infarcts) and the pattern of cerebral infarcts (cortical, border zone, or perforating artery territory infarcts). The data of microembolic signals and diffusion‐weighted magnetic resonance imaging were assessed blindly and independently by separate observers. Diffusion‐weighted magnetic resonance imaging showed that 15 patients (50%) had single acute cerebral infarcts and 15 patients had multiple acute cerebral infarcts. Among patients with multiple acute infarcts, unilateral, deep, chainlike border zone infarcts were the most common pattern (11 patients, 73%), and for single infarcts, penetrating artery infarcts were the most common (10 patients, 67%). Microembolic signals were detected in 10 patients (33%). The median number of microembolic signals per 30 minutes was 15 (range, 3–102). Microembolic signals were found in 9 patients with multiple infarcts and in 1 patient with a single infarct (p = 0.002, χ2). The number of microembolic signals predicted the number of acute infarcts on diffusion‐weighted magnetic resonance imaging (linear regression, adjusted R2 =0.475, p < 0.001). Common stroke mechanisms in patients with middle cerebral artery stenosis are the occlusion of a single penetrating artery to produce a small subcortical lacuna‐like infarct and an artery‐to‐artery embolism with impaired clearance of emboli that produces multiple small cerebral infarcts, especially along the border zone region.
Investigation of properties, nanostructure, and distribution in controlled polyester polymerization with layered silicate
Authors: Ke Yang‐Chuan , Yang Zhi‐Bin , Zhu Chuan‐Feng
Published: October 2002

This article presents a series of nanocomposites of a polyester [poly (ethylene terephathalate), PET] with different contents of layered silicates of montmorillonite (MMt) by a controlled process, that is, controlling the way to pretreat MMt, the content of MMt, the kind of reagents used, and the way for MMt to be added. Also investigated, in detail, were the properties, nanostructure, and distribution of nanocomposites with an MMt content below 5% by weight. Results by TEM and AFM showed that the nanoparticles are in a normal distribution with a most probable size of 30–70 nm; the exfoliated MMt lamellae interacting with the PET molecular chain produced more regular chain patterns than did pure PET itself when the MMt content was low (lower than 3% by weight); and the agglomerated particles seem not to be found in an MMt content less than 3% by weight, but to increase with the MMt content in the nanocomposites. The investigation of these nanocomposite properties showed that the optimized properties require an optimized MMt content within 2–3% by weight. When MMt is increased from 3 to 5% by weight in the nanocomposites, agglomeration is unavoidable. Thus, the critical content for MMt added to PET is about 3% by weight. X‐ray results showed the appearance of several small diffraction peaks in the 2θ angle from 1° to 7° for the annealing nanocomposite samples; these peaks are thought to be from the residue of unexfoliated MMt lamellae or metastable (unstable) MMt lamellae. DSC results proved that the nanocomposites have a higher crystallization rate than that of pure PET due to an exfoliated MMt lamellae nucleation effect. Thus, to obtain a stable nanostructure (or nanocomposite), the MMt content needs to be controlled. The nanostructure plays such a role in the crystallization nucleation of nanocomposites. The interaction of exfoliated lamellae with the molecular chain causes a more regular chain pattern and affects the PET crystallization rate and morphology. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2677–2691, 2002
Mechanical properties and morphology of PA6/EVA blends
Authors: Bhattacharyya Arup R. , Maiti S. N. , Misra Ashok
Published: October 2002

The mechanical properties of blends of polyamide6 (PA6) and ethylene vinyl acetate (EVA) at a blending composition of 0–50 wt % EVA were studied. The notched Izod impact strength of PA6 increased with the incorporation of EVA, the increase being more than 100% compared to PA6 at 10% EVA. The tensile strength and the tensile modulus of the blends decreased steadily as the weight percent of EVA increased. Analysis of the tensile data using predictive theories indicated the extent of the interaction of the dispersed phase and the matrix up to 20 wt % EVA. SEM studies of the cryogenically fractured surfaces indicated increase in the dispersed phase domain size with EVA concentrations. On the other hand, impact fractured surfaces of PA6/EVA blends indicated debonding of EVA particles, leaving hemispherical bumps, indicating inadequate interfacial adhesion between PA6 and EVA. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1593–1606, 2002
A study on new polymerization technology of styrene
Authors: Si Linxu , Zheng Anna , Yang Haibo , Guo Renyi , Zhu Zhongnan , Zhang Yongming
Published: October 2002

The classic polymerization technology of polystyrene is a high‐cost and nonfriendly environmental technology. Furthermore, the weight‐average molecular weight of polystyrene is hard to enhance up to 400,000 in the classic polymerization technology. The disadvantages limit the growth rate of polystyrene. The solution for increasing the growth rate of polystyrene lies in new technology. The reactive extrusion process of polystyrene was studied in detail and the whole reactive extrusion process of polystyrene was obtained. By means of controlling the flow rate of styrene and the initiator and the screw rotational speed, samples of polystyrene with different molecular weights were synthesized by the twin‐screw extruder. The properties of synthesized polystyrene with different molecular weights were studied; the mechanic properties of polystyrene will increase with an increase of the weight average molecular weight of polystyrene. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2130–2135, 2002
Application of factorial experimental design to study the influence of polymerization conditions on the yield of polyaniline powder
Authors: Chen Cheng‐Ho
Published: October 2002

Influences of chemical oxidation polymerization conditions on the yields of polyaniline powder were investigated. These chemical oxidation polymerization conditions included polymerization time, concentration of HNO3, mol ratio of ammonium persulfate/aniline (APS/AN), and polymerization temperature. If polymerization time, concentration of HNO3, mol ratio of APS/AN, and polymerization temperature were 60 min, 1.0 M, 1.0, and 0°C, respectively, then the yield of emeraldine base form polyaniline powder was around 78.1%. The yield of polyaniline powder increased significantly with the polymerization time, concentration of HNO3, and the mol ratio of APS/AN. A 23 factorial experimental design was applied to study the main, two‐factor interaction, and three‐factor interaction effects of polymerization time, concentration of HNO3, and mol ratio of APS/AN on the yield of polyaniline powder. According to the definition, the sequence of the main effects on the yield of polyaniline powder, in ascending order, is concentration of HNO3 < mol ratio of APS/AN < polymerization time. The sequence of the two‐factor interaction effects on the yield of polyaniline, in ascending order, is concentration of HNO3 vs. mol ratio of APS/AN < polymerization time vs. concentration of HNO3 < polymerization time vs. mol ratio of APS/AN. Meanwhile, the prediction equation by definition is: Ŷ = 0.287+0.145X1+0.091X2+0.121X3+0.023X1X2+0.111X1X3+0.002X2X3+0.003X1X2X3. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 1571–1580, 2002
Flow‐injection polymer analysis of ethylene propylene diene monomer elastomers. I
Authors: Poché Drew S. , Brown Raymond J. , Meiske Larry
Published: October 2002

A rapid, flow‐injection polymer analysis (FIPA) method for the solution characterization of EPDM elastomers, with a wide range of ethylene comonomer content, was developed. Solutions of the polymer were introduced into a flowing mobile phase which was monitored by an array of three detectors: a right‐angle laser light‐scattering unit, a differential refractive index detector, and a differential pressure viscometer. To adequately characterize a wide range of comonomer composition, it was found that a nominal temperature of 90°C and a solvent (e.g., 1,2,4‐trichlorobenzene) capable of high‐temperature sample dissolution was needed for the analysis. Polymer association or aggregation was observed in cyclohexane at lower analysis temperatures. With an analysis time of a few minutes, information on molecular weight, molecular size, and comonomer composition can be obtained directly. Information regarding polydispersity and properties such as melt viscosity may be obtained indirectly or through correlation to other, independent property measurements. The data were also compared to a high‐temperature GPC analysis method already in use. The combination of rapid analysis time and measurement of fundamental molecular properties suggests the usefulness of the instrumentation and method to plant process control. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2178–2189, 2002
Water in different poly(styrene sulfonic acid)‐grafted fluoropolymers
Authors: Walsby Nadia , Hietala Sami , Maunu Sirkka Liisa , Sundholm Franciska , Kallio Tanja , Sundholm Göran
Published: October 2002

We investigated the water present in a series of radiation‐grafted fluoropolymers with similar poly(styrene sulfonic acid) (PSSA) contents with the aim of determining the influence of the initial fluoropolymer. Radiation‐grafted membranes were compared with Nafion 117 and 105. Sorption curves and differential scanning calorimetry thermograms showed that all the membranes contained the same number of water molecules tightly bound to the sulfonic acid groups; this water did not freeze. In radiation‐grafted membranes, the content of freezing water absorbed from the liquid‐phase water varied according to the swelling abilities of the membrane, which were dependent on the initial fluoropolymer. Larger pores accompanied high water uptakes and high conductivity. The amount of water absorbed from the vapor phase was similar for all radiation‐grafted membranes with similar PSSA contents, irrespective of matrix material. Nafion membranes had higher conductivities at intermediate hydration levels, and the relaxation times measured by NMR were longer than for the radiation‐grafted materials. This suggests that the channels for water and proton conduction are different in the two types of materials. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 33–42, 2002
Peroxomonosulphate initiated graft copolymerization of o‐toluidine onto nylon 6 and wool fibers—A kinetic approach
Authors: Anbarasan R. , Jayaseharan J. , Gopalan A.
Published: October 2002

Chemical polymerization of o‐toluidine (OT) in the presence of nylon 6 and wool fibers initiated by peroxomonosulphate (PMS) in an aqueous acidic medium was carried out under nitrogen atmosphere. During the polymerization process, graft copolymers were formed along with homopolymers of OT. A procedure is given for the separation of poly(o‐toluidine) (POT) grafted fiber from the homopolymer. Rate of homopolymerization (Rh), rate of grafting (Rg), percentage grafting, and percentage grafting efficiency were determined. Rate constants were evaluated from the experimental results. The chemical grafting of POT onto nylon 6 and wool fibers was confirmed through Fourier transform infrared (FTIR) spectroscopy and electrical conductivity measurements. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 2317–2326, 2002
Studies on blends of high‐density polyethylene and polypropylene produced by oscillating shear stress field
Authors: Zhang Gong , Fu Qiang , Shen Kaizhi , Jian Long , Wang Yong
Published: October 2002

Tensile strength and morphology of blends of high‐density polyethylene (HDPE) and polypropylene (PP) obtained by oscillating packing injection molding were investigated via Universal Testing Machine, DSC, and SAXS. Tensile strength is greatly enhanced from 24.5 MPa to more than 90 MPa for pure HDPE and for blends with PP content less than 10 wt %. There exists a sharp decrease of tensile strength when PP content is more than 10 wt %. The shear‐induced morphologies with core in the center, oriented zone surrounding the core and skin layer are observed in the cross‐section areas of the samples. Interestingly, a sharp decrease of oriented zone is seen when PP content is more than 10 wt %, associated with the sharp decrease of tensile strength. DSC result shows double melting peaks with a high‐temperature melting peak that is not present in the endotherm obtained from the central core and obtained from the samples by static packing injection molding, which indicates the existence of shish‐kebab structure in the oriented zone. However, there is no difference of crystallinity between the samples by oscillating and by static packing injection molding. SAXS was used to analyze the complicated morphologies induced by shear stress, and results show that the crystal thickness could be greatly increased under shear stress. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 58–63, 2002
Free radical grafting of itaconic acid and glycidyl methacrylate onto PP initiated by organic peroxides
Authors: Pesetskii S. S. , Jurkowski B. , Makarenko O. A.
Published: October 2002

Comparative analysis was conducted to learn the grafting of itaconic acid (IA) and glycidyl methacrylate (GMA) onto polypropylene (PP) in the course of reactive extrusion. Seven organic peroxides, which satisfactorily dissolve in PP, but do not dissolve in the monomer, were used to initiate free‐radical reactions. The grafting of IA and GMA onto PP initiated by certain peroxides gave approximately equal amounts of grafted product. It was learned that the nature of peroxide initiators is decisive for grafting efficiency and degree of macromolecular degradation. To ensure a high yield of grafted product, it is advisable to use peroxides, which have thermodynamic affinity with PP and the temperature range of decomposition of which corresponds to the thermal regime of reactive extrusion. Di(tert‐butyl peroxy‐isopropyl)‐benzene (P‐14) appeared to meet for the most these requirements for grafting both GMA and IA. Grafting is accompanied by β‐decomposition of the chains irrespective of the type of peroxide and monomer used; hence, the MFI increases. A considerable rise in MFI was observed at a minimum peroxide concentration (0.1wt %). Degradation of PP during modification eases its crystallization from the melt. In this case the crystallization temperature is 5 to 8.5°C higher than of the original PP, and the crystallinity degree increases by 20 to 60%. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 64–72, 2002
Phase behavior and morphology in blends of poly(L‐lactic acid) and poly(butylene succinate)
Authors: Park Jun Wuk , Im Seung Soon
Published: October 2002

Blends of poly(L‐lactic acid) (PLA) and poly(butylene succinate) (PBS) were prepared with various compositions by a melt‐mixing method and the phase behavior, miscibility, and morphology were investigated using differential scanning calorimetry, wide‐angle X‐ray diffraction, small‐angle X‐ray scattering techniques, and polarized optical microscopy. The blend system exhibited a single glass transition over the entire composition range and its temperature decreased with an increasing weight fraction of the PBS component, but this depression was not significantly large. The DSC thermograms showed two distinct melting peaks over the entire composition range, indicating that these materials was classified as semicrystalline/semicrystalline blends. A depression of the equilibrium melting point of the PLA component was observed and the interaction parameter between PLA and PBS showed a negative value of −0.15, which was derived using the Flory–Huggins equation. Small‐angle X‐ray scattering revealed that, in the blend system, the PBS component was expelled out of the interlamellar regions of PLA, which led to a significant decrease of a long‐period, amorphous layer thickness of PLA. For more than a 40% PBS content, significant crystallization‐induced phase separation was observed by polarized optical microscopy. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 647–655, 2002
Homogeneous fluorescent labeling of cationic polyacrylamides
Authors: Tanaka Hiroo , Swerin Agne , Ödberg Lars , Tanaka Masayoshi
Published: October 2002

A number of fluorescently labeled polymers have already been prepared. Since these polymers have usually been synthesized by copolymerization, the distribution of fluorescent groups will in such a case be heterogeneous because monomers always have different reactivity ratios. In this article, the preparation of fluorescently labeled cationic polyacrylamides (C‐PAM) with homogeneous distributions of both fluorescent and cationic groups is described. Four fluorescently labeled C‐PAM with isoindol, pyrene, anthracene, and dansyl groups were prepared in the homogeneous reaction system. These polymers were water soluble. Their wavelengths for maximum emission were in order of the above 380, 382 (smaller peak at 400), 435, and 540 nm, which thus covered a wide wavelength range. It is noteworthy that C‐PAM with pyrene and anthracene groups have little fluorescence intensity at 540 nm, which is the maximum emission wavelength for C‐PAM with dansyl group, making an accurate determination of the two polymers in the same solution possible. Even at the low degree of labeling, the detection limit of polymers is very low (approximately 1 ppm). © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 672–675, 2002
Synthesis and characterization of a positive‐working, aqueous‐base‐developable photosensitive polyimide precursor
Authors: Hsu Steve Lien‐Chung , Lee Po‐I , King Jinn‐Shing , Jeng Jyh‐Long
Published: October 2002

A positive‐working, aqueous‐base‐developable photosensitive polyimide precursor based on poly(amic ester)‐bearing phenolic hydroxyl groups and a diazonaphthoquinone photosensitive compound was developed. The poly(amic ester) was prepared from a direct polymerization of 2,2′‐bis‐(3‐amino‐4‐hydroxyphenyl)hexafluoropropane and bis(n‐butyl)ester of pyromellitic acid in the presence of phenylphosphonic dichloride as an activator. Subsequently, the thermal imidization of the poly(amic ester) precursor at 300°C produced the corresponding polyimide. The inherent viscosity of the precursor polymer was 0.23 dL/g. The cyclized polyimide showed a glass‐transition temperature at 356°C and a 5% weight loss at 474°C in nitrogen. The structures of the precursor polymer and the fully cyclized polymer were characterized by Fourier transform infrared spectroscopy and 1H‐NMR. The photosensitive polyimide precursor containing 25 wt % diazonaphthoquinone photoactive compound showed a sensitivity of 150 mJ/cm2 and a contrast of 1.65 in a 3 μm film with 1.25 wt % tetramethylammonium hydroxide developer. A pattern with a resolution of 10 μm was obtained from this composition. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 352–358, 2002
Oxazoline‐containing compatibilizers for polyamide/SAN and polyamide/ABS blends
Authors: Liu Xiaodong , La Mantia Francesco , Scaffaro Roberto
Published: October 2002

Polyamide (PA) and acrylonitrile/butadiene/styrene copolymer (ABS) may appear as a mixture in the recycled plastic stream. The incompatibility of these blends results in a blend with poor mechanical properties. The aim of this work is to partially convert the nitrile groups of the acrylonitrile/styrene copolymer (SAN) into oxazoline groups by reaction with aminoethanol (AE). Such modified SAN (SAN‐m) can react with the amine or carboxylic acid end groups of PA, and therefore used as compatibilizers for blends of PA with ABS. SAN‐m was found to reduce the SAN‐domain size in the PA/SAN‐blends. The initial acrylonitrile content of SAN‐m had a strong influence on the degree of conversion into oxazoline groups and on the compatibilizing effect. Mechanical properties of SAN‐m compatibilized PA/ABS blends were investigated. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 449–455, 2002
Reactions of adenine with ethylene oxide and propylene oxide
Authors: Lubczak Renata
Published: October 2002

Reactions leading to thermostable polyetherols containing purine rings were studied. Products of reaction of adenine and an excess of the oxiranes were analyzed by proton nuclear magnetic resonance and infrared spectroscopies. The physical properties of some of the products were determined. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 489–497, 2002
Localization of the transmembrane proteoglycan syndecan‐4 and its regulatory kinases in costameres of rat cardiomyocytes: A deconvolution microscopic study
Authors: VanWinkle W. Barry , Snuggs Mark B. , De Hostos Eugenio L. , Buja L. Maximilian , Woods Anne , Couchman John R.
Published: October 2002

Syndecan‐4 (syn‐4), a transmembrane heparan sulfate‐containing proteoglycan, is unique among the four members of the syndecan family in its specific cellular localization to complex cytoskeletal adhesion sites, i.e., focal adhesions. During early phenotypic redifferentiation of neonatal cardiomyocytes in culture, immunolocalization reveals syn‐4 to be heavily concentrated in the perinuclear endoplasmic reticulum‐Golgi region, with little found at the peripheral regions. Subsequently, syn‐4 becomes localized to a cytoskeletal adhesion complex unique to striated muscle, the costamere. Soon after redifferentiation of myofibrils in cultured neonatal cardiomyocytes, syn‐4 is present only in costameres, not in focal adhesions. In cultured adult cardiomyocytes, it is present in both costameres and focal adhesions—the latter in two distinct regions of the spread cardiomyocytes, reflecting localization with two types of actin‐containing filaments. The fact that syn‐4 is observed early in the costameric regions, as opposed to later in the focal adhesions, suggests that it may play an initial role in early adhesion/signal transduction mechanisms in close proximity to the contractile apparatus, as well as in transmission of contractile force to the collagenous extracellular matrix (ECM) which surrounds the cardiac myofibers in situ. With respect to possible regulatory mechanisms of syn‐4, we localized syn‐4 with both the ϵ isoform of protein kinase C and the tyrosine kinase pp60csrc in costameric regions. These findings suggest that syn‐4 may not only play a role in cellular adhesion and contractile force transmission, it may also, through ser, thr, and tyr phosphorylation, be part of an interactive signal transduction mechanism in myocardial functioning via these adhesive cytoskeletal complexes. Anat Rec 268:38–46, 2002. © 2002 Wiley‐Liss, Inc.
Purification and characterization of nucleoside diphosphate kinase from the brain of Bombyx mori
Authors: Uno Tomohide , Ueno Mayumi , Kikuchi Michiko , Aizono Yasuo
Published: October 2002

Nucleoside diphosphate kinase in the brain of Bombyx mori was purified by ammonium sulfate fractionation, and a sequence of chromatographies on DEAE‐Cellulofine, hydroxyapatite, Mono‐S, and Mono‐Q column. The purified enzyme preparation was found to be electrophoretically homogeneous on SDS‐PAGE, and its molecular mass was determined to be 18 kDa. The purified protein was digested and the amino acid sequences of resulting peptides were determined. The enzyme showed high similarity to the amino acid sequences of the Drosophila NDP kinase. The enzyme showed NDP kinase activity and mediated the phosphorylation of myelin basic protein. Gel filtration and Hill plot analysis indicate that the purified NDP kinase forms a tetramer and shows little interaction among substrates. Dephosphorylation of NDP kinase by bacterial alkaline phosphatase increased NDP kinase activity. This result indicates that phosphorylation of NDP kinase represses NDP kinase activity. Arch. Insect Biochem. Physiol. 50:147–155, 2002. © 2002 Wiley‐Liss, Inc.
Juvenile hormone stimulated tyrosine kinase‐mediated protein phosphorylation in the CNS of the silk worm, Bombyx mori
Authors: Arif A. , Shanavas A. , Murthy Ch. R. K. , Dutta‐Gupta Aparna
Published: October 2002

In vitro studies with the larval CNS of the silkworm, Bombyx mori revealed the phosphorylation of a 48‐kDa protein, which was not dependent on cyclic nucleotides. Studies also revealed modest phosphorylation of this protein by a calcium‐dependent but calmodulin‐independent mechanism. However, phosphorylation of this protein was greatly enhanced in the presence of juvenile hormone (JH) I by a calcium‐independent mechanism. This stimulatory effect of JH was seen in both homogenates as well as in intact CNS of Bombyx. Immunoblotting studies revealed the cross‐reaction of this 48‐kDa protein with phosphotyrosine monoclonal antibody and the phosphorylation of this protein was inhibited by genistein. This study suggests that the 48‐kDa protein is a substrate for tyrosine kinase. The phosphorylation of this protein was also observed in other larval tissues such as salivary gland, fat body, and epidermis of Bombyx. Arch. Insect Biochem. Physiol. 50:139–146, 2002. © 2002 Wiley‐Liss, Inc.
Two juvenile hormone suppressible storage proteins may play different roles inHyphantria cuneaDrury
Authors: Cheon Hyang‐Mi , Hwang Su‐Jeong , Kim Hong‐Ja , Jin Byung Rae , Chae Kwon‐Seok , Yun Chi‐Young , Seo Sook‐Jae
Published: October 2002

We isolated and sequenced cDNA clones corresponding to two storage proteins (HcSP‐1 and HcSP‐2) from fall webworm,Hyphantria cunea. The cDNAs for HcSP‐1 (2,337 bp) and HcSP‐2 (2,572 bp) code for 753 and 747 residue proteins with predicted molecular masses of 88.3 and 88.5 kDa, respectively. The calculated isoelectric points are pI = 8.4 (HcSP‐1) and 7.6 (HcSP‐2). Multiple alignment analysis of the amino acid sequence revealed that HcSP‐1 is most similar to SL‐1 fromS. litura(73.8% identity) and other methionine‐rich hexamers, whereas HcSP‐2 is most similar to the SL‐2 α subunit fromS. litura(74.8% identity) and other moderately methionine‐rich hexamers. The two storage proteins fromH. cuneashared only 38.4% identity with one another. According to both phylogenetic analyses and the criteria of amino acid composition, HcSP‐1 belongs to the subfamily of Met‐rich storage proteins (6% methionine, 10% aromatic amino acid), and HcSP‐2 belongs to the subfamily of moderately methionine‐rich storage proteins (3.2% methionine, 12.9% aromatic amino acid). Topical application of the JH analog, methoprene, after head ligation of larvae, suppressed transcription of the SP genes, indicating hormonal effects at the transcriptional level. The HcSP‐1 transcript was detected by Northern blot analysis in Malpighian tubule, testis, and ovary, in addition to fat body where it was most abundant. The HcSP‐2 transcript was detected only in fat body and Malpighian tubule. The accumulation of HcSP‐1 in ovary and HcSP‐2 in Malpighian tubule might be related to differential functions in both organs. Arch. Insect Biochem. Physiol. 50:157–172, 2002. © 2002 Wiley‐Liss, Inc.
Inadequately low serum levels of steroid hormones in relation to interleukin‐6 and tumor necrosis factor in untreated patients with early rheumatoid arthritis and reactive arthritis
Authors: Straub Rainer H. , Paimela Leena , Peltomaa Ritva , Schölmerich Jürgen , Leirisalo‐Repo Marjatta
Published: October 2002

Objective

To compare levels of steroid hormones in relation to cytokines and to study levels of cortisol or dehydroepiandrosterone (DHEA) in relation to other adrenal hormones in untreated patients with early rheumatoid arthritis (RA) and reactive arthritis (ReA) compared with healthy controls.

Methods

In a retrospective study with 34 RA patients, 46 ReA patients, and 112 healthy subjects, we measured serum levels of interleukin‐6 (IL‐6), tumor necrosis factor (TNF), adrenocorticotropic hormone (ACTH), cortisol, 17‐hydroxyprogesterone (17‐OH‐progesterone), androstenedione (ASD), DHEA, and DHEA sulfate (DHEAS).

Results

RA patients had higher serum levels of IL‐6, TNF, cortisol, and DHEA compared with ReA patients and healthy subjects, but no difference was noticed with respect to ACTH and DHEAS. However, in RA and ReA patients compared with healthy subjects, levels of ACTH, cortisol, ASD, DHEAS, and 17‐OH‐progesterone were markedly lower in relation to levels of IL‐6 and TNF. Furthermore, the number of swollen joints correlated inversely with the ratio of serum cortisol to serum IL‐6 in RA (RRank = −0.582, P = 0.001) and, to a lesser extent, in ReA (RRank = −0.417, P = 0.011). In RA patients, the mean grip strength of both hands was positively correlated with the ratio of serum cortisol to serum IL‐6 (RRank = 0.472, P = 0.010). Furthermore, in these untreated patients with RA and ReA, there was a relative decrease in the secretion of 17‐OH‐progesterone, ASD, and DHEAS in relation to DHEA and cortisol. This indicates a relative predominance of the nonsulfated DHEA and cortisol in relation to all other measured adrenal steroid hormones in the early stages of these inflammatory diseases.

Conclusion

This study indicates that levels of ACTH and cortisol are relatively low in relation to levels of IL‐6 and TNF in untreated patients with early RA and ReA compared with healthy subjects. The study further demonstrates that there is a relative increase of DHEA and cortisol in relation to other adrenal hormones, such as DHEAS. This study emphasizes that adrenal steroid secretion is inadequately low in relation to inflammation. Although changes in hormone levels are similar in RA and ReA, alteration of steroidogenesis is more pronounced in RA patients than in ReA patients.
Increased urinary F2‐isoprostanes in systemic sclerosis, but not in primary Raynaud's phenomenon: Effect of cold exposure
Authors: Cracowski Jean‐Luc , Carpentier Patrick H. , Imbert Bernard , Cachot Sandrine , Stanke‐Labesque Françoise , Bessard Janine , Bessard Germain
Published: October 2002

Objective

F2‐isoprostanes are free radical‐dependent arachidonic acid metabolites that are used as clinical markers of lipid peroxidation in systemic sclerosis (SSc) and other microvascular diseases. The objectives of this study were to determine whether the basal urinary levels of F2‐isoprostane in SSc patients differ from those in patients with primary Raynaud's phenomenon (RP) and to investigate whether F2‐isoprostane formation correlates with the cutaneous microvascular perfusion decrease following cold exposure in SSc patients, patients with primary RP, and healthy controls.

Methods

Eleven women with RP secondary to SSc, 11 women with primary RP, and 11 healthy women were exposed to decreasing room temperature, from 25°C to 15°C, for 40 minutes. Urine samples were obtained before and after the test for gas chromatography/electronic impact mass spectrometry quantification of 15‐F2t‐isoprostane (15‐F2t‐IsoP; also called isoprostaglandin F2α type III). Cutaneous blood flow was monitored using a laser Doppler perfusion imager.

Results

The mean ± SEM urinary 15‐F2t‐IsoP levels at baseline in SSc patients (178 ± 32 pmoles/mmole of creatinine) were 1.9 times higher than those in healthy controls (95 ± 11 pmoles/mmole of creatinine) and 1.7 times higher than those in patients with primary RP (107 ± 19 pmoles/mmole of creatinine) (P < 0.05 for controls and patients with primary RP versus SSc patients). No significant correlation was found between basal urinary 15‐F2t‐IsoP levels and the temperature or cutaneous blood flow decrease in response to the whole‐body cooling. Furthermore, the 15‐F2t‐IsoP response to the cooling test was not correlated with the cutaneous blood flow decrease.

Conclusion

Lipid peroxidation is increased in SSc patients, but not in patients with primary RP. Cold exposure leads to a significant but small increase in 15‐F2t‐IsoP levels that is independent of the cutaneous blood flow decrease. F2‐isoprostane quantification may be an interesting pharmacologic tool for monitoring responses to antioxidant treatment in SSc patients.
High prevalence of lateral knee osteoarthritis in Beijing Chinese compared with Framingham Caucasian subjects
Authors: Felson David T. , Nevitt Michael C. , Zhang Yuqing , Aliabadi Piran , Baumer Bridget , Gale Daniel , Li Wei , Yu Wei , Xu Ling
Published: October 2002

Objective

We recently reported that, despite their thinness, elderly subjects in Beijing, China had an equal prevalence (in men) or higher prevalence (in women) of both radiographic and symptomatic knee osteoarthritis (OA) compared with that in the Framingham, Massachusetts cohort of elderly subjects. Our objective was to evaluate whether Chinese subjects might have more medial disease than do Caucasians, given a report of varus alignment in the knee joints of Chinese elderly.

Methods

We compared the prevalence of medial and lateral radiographic knee OA and measured anatomic alignment in the knees of elderly subjects from the Beijing and Framingham cohorts. Both studies recruited a random sample of the population. The Beijing OA Study used the Framingham OA Study protocol for radiographs. Anteroposterior weight‐bearing films were read for Kellgren and Lawrence (K/L) grade and joint space narrowing (JSN; 0–3 scale) in each compartment. Medial disease was defined when radiographs showed a K/L grade ≥2 and medial JSN ≥1, and lateral disease was assessed in a comparable manner. Using knee‐specific analyses, we compared the prevalence of medial and lateral knee OA after adjusting for age, body mass index, and the correlation between the 2 knees. Restricting the analyses to knees with JSN ≥2 and comparing the proportion of OA knees with medial disease and lateral disease yielded similar results. We assessed alignment in knees from 100 persons without OA, measuring the angle subtended by the femoral and tibial anatomic axes.

Results

We studied 1,781 Chinese subjects ages 60–88 years, and 1,084 Framingham subjects ages 63–93 years. Whereas medial OA was less prevalent among the Beijing men, lateral OA was more than twice as prevalent among the Beijing men and women, compared with that in the Framingham elderly. For example, of all knees with radiographic OA, 28.5% of Beijing women's knees had lateral OA versus 11% of Framingham women's knees (P < 0.001), and among men, 32.3% of Beijing men's knees versus 8.8% of Framingham men's knees (P < 0.001) had lateral OA. Alignment was more valgus in the Beijing men than in the Framingham men (mean 4.5° versus 2.7° valgus, respectively; P < 0.001), but no differences in alignment were evident in the women.

Conclusion

In this first attempt to compare the characteristics of OA in different racial groups, we conclude that, opposite to expectations, Chinese subjects have much more lateral OA than do Caucasian subjects in the Framingham cohort, a predilection possibly explained in the men by differences in anatomic alignment.
Acute low back pain self‐management intervention for urban primary care patients: Rationale, design, and predictors of participation
Authors: Damush Teresa M. , Weinberger Morris , Clark Daniel O. , Tierney William M. , Rao Jaya K. , Perkins Susan M. , Verel Kelly
Published: October 2002

Objectives

To describe the rationale and design of a self‐management program for low‐income, urban, primary care patients with acute low back pain. Issues related to recruitment and protocol delivery, and attendance patterns and predictors of program attendance are described.

Methods

Two hundred eleven adult patients (73% female; 60% African American) were recruited from primary care neighborhood health centers. Focus groups were conducted for program development, and participants then completed a baseline interview and were randomized into groups receiving either usual care or a self‐management intervention.

Results

Twenty‐nine percent of the intervention group attended the self‐management class. Significant predictors of attendance included being older, reporting less income, and not working for pay. Attendees did not differ from nonattendees on back pain severity, symptoms, health‐related quality of life, self‐management processes, or satisfaction with care.

Conclusion

Effective minimal‐contact behavioral interventions are needed to reach larger portions of the patient population.
Use of a numerical rating scale as an answer modality in ankylosing spondylitis–specific questionnaires
Authors: van Tubergen Astrid , Debats Iris , Ryser Liliane , Londoño John , Burgos‐Vargas Ruben , Cardiel Mario H. , Landewé Robert , Stucki Gerold , Van der Heijde Désirée
Published: October 2002

Objectives

To determine the agreement of scores on the original visual analog scale (VAS) or Likert scale of the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI), Bath Ankylosing Spondylitis Functional Index (BASFI), and Dougados Functional Index (DFI) with scores on a numerical rating scale (NRS). To assess the reproducibility and responsiveness of the instruments with the original scale and NRS.

Methods

Five hundred thirty‐six patients with ankylosing spondylitis from the Netherlands, Mexico, and Switzerland completed a questionnaire in which all questions from the BASDAI, BASFI, and DFI were presented twice in random order with an 11‐point NRS and either a 10‐cm VAS (BASDAI and BASFI) or a 5‐point Likert scale (DFI). Agreement of scores using Bland‐Altman plots and intraclass correlation coefficients (ICCs), reproducibility using ICCs, and responsiveness were assessed.

Results

Large variability between the scores on the original scales and the NRS was found in individual questions of all 3 questionnaires, although total scores showed ICCs of at least 0.88. Reproducibility of all answer modalities showed low ICCs in individual questions, but moderate to good ICCs in total scores (Dutch group 0.62–0.89; Mexican group 0.53–0.72). Moderate to large effects (0.48–1.04) were found in responsiveness scores in the 3 questionnaires. No major differences in reproducibility and responsiveness between the answer modalities were found.

Conclusion

Although large variability between the scores on the original answer scales and the NRS was observed, the BASDAI, BASFI, and DFI can be administered with an NRS, which does not show important differences compared with the original scales.
Efficacy of tacrolimus in rheumatoid arthritis patients who have been treated unsuccessfully with methotrexate: A six‐month, double‐blind, randomized, dose‐ranging study
Authors: Furst Daniel E. , Saag Kenneth , Fleischmann M. Roy , Sherrer Yvonne , Block Joel A. , Schnitzer Thomas , Rutstein Joel , Baldassare Andrew , Kaine Jeffrey , Calabrese Leonard , Dietz Frederick , Sack Marshall , Senter R. Gordon , Wiesenhutter Craig , Schiff Michael , Stein C. Michael , Satoi Yoichi , Matsumoto Alan , Caldwell Jacques , Harris Robert E. , Moreland Larry W. , Hurd Eric , Yocum David , Stamler David A.
Published: October 2002

Objective

To assess the efficacy, safety, and optimal dose of tacrolimus monotherapy in patients with rheumatoid arthritis (RA).

Methods

This phase II, randomized, double‐blind, placebo‐controlled monotherapy study was set in 12 community sites and 9 university‐based sites. Two hundred sixty‐eight patients with RA who were resistant to or intolerant of methotrexate (mean dose 15.2 mg/week) and had active disease for at least 6 months (mean tender joint count 28.2, mean erythrocyte sedimentation rate 46.5 mm/hour) were randomized to receive treatment after discontinuation of methotrexate. Those who received at least 1 dose of tacrolimus were analyzed; 141 completed the study. Stable dosages of nonsteroidal antiinflammatory drugs and low‐dose prednisone were allowed during treatment. All patients were given 1, 3, or 5 mg of tacrolimus or placebo once daily for 24 weeks. The American College of Rheumatology definition of 20% improvement (ACR20) and the tender and swollen joint counts at the end of treatment were the primary outcomes.

Results

ACR20 response rates demonstrated a clear dose response. The ACR20 response was observed in 15.5% of patients receiving placebo (95% confidence interval [95% CI] 7.1–23.9%), 29% of the 1 mg tacrolimus group (95% CI 18.3–39.7%) (P < 0.058); 34.4% of the 3 mg group (95% CI 22.7–46.0%) (P < 0.013), and 50% of the 5 mg group (95% CI 37.8–62.3%) (P ≤ 0.001). The tender joint count improved statistically significantly in all tacrolimus groups. The swollen joint count, physical function, and patient‐assessed pain improved statistically significantly in the 3 mg and 5 mg groups. The incidence of creatinine elevation ≥40% above baseline levels increased in a dose‐dependent manner. Dropout rates were high (41–59%) and were more common for inefficacy in the placebo patients (71.4%), whereas they were more common for toxicity in the high‐dose tacrolimus groups (31–33%). Discontinuation for creatinine elevation occurred in the 3 mg (3.1%) and 5 mg (10.9%) tacrolimus groups.

Conclusion

Tacrolimus improved disease activity in methotrexate‐resistant or ‐intolerant patients with RA. A dose response was observed when efficacy and toxicity were assessed at different doses. The optimal dose of tacrolimus appears to be >1 mg but ≤3 mg daily.
Light‐activated gene transduction enhances adeno‐associated virus vector–mediated gene expression in human articular chondrocytes
Authors: Ulrich‐Vinther Michael , Maloney Michael D. , Goater J. Jeffrey , Søballe Kjeld , Goldring Mary B. , O'Keefe Regis J. , Schwarz Edward M.
Published: October 2002

Objective

To evaluate the effects of ultraviolet (UV) light as an adjuvant for recombinant adeno‐associated virus (rAAV) transduction in human articular chondrocytes.

Methods

Primary articular chondrocytes and immortalized chondrocytes (tsT/AC62) were exposed to various doses of UV light (0–1,000 J/m2) and infected at various multiplicities of infection (MOIs) with rAAV containing the enhanced green fluorescent protein (EGFP) gene. Cells were analyzed for viability and EGFP expression by fluorescence‐activated cell sorting on days 2, 4, and 8 following infection. To evaluate the transduction efficiency in intact articular cartilage, full‐thickness explants were exposed to UV light (0–200 J/m2), infected with rAAV‐eGFP, and analyzed for transduction via immunohistochemistry.

Results

Toxicity from UV exposure was observed at doses ≥500 J/m2 and ≥200 J/m2 in primary and immortalized chondrocyte cultures, respectively. Transduction efficiency was dependent on the UV dose, MOI, and time. In the cell line, the adjuvant effect of UV on the percentage of cells transduced was modest, but 100 J/m2 increased the mean fluorescence intensity (MFI) of the transduced cells 4‐fold. In contrast, UV treatment had a profound effect on the transduction efficiency of primary chondrocytes, which reached ∼100% after exposure to 100 J/m2 of UV light and 103 MOIs for 8 days. Under the same conditions, 200 J/m2 of UV light enhanced the MFI 7‐fold. In cartilage explants, there was no difference in the number of transduced chondrocytes at the edge of the explants in the superficial, intermediate, or basal zones; however, 200 J/m2 of UV light increased the transduction efficiency 2‐fold at a low MOI. In the center of the explants, the superficial chondrocytes were efficiently transduced; those in the intermediate and basal zones could not be efficiently transduced under any condition. In the superficial chondrocytes, a low MOI and 200 J/m2 of UV light increased the transduction efficiency 3‐fold (to 100%).

Conclusion

UV light at doses of up to 200 J/m2 (which do not significantly affect cell viability) significantly enhances the transduction efficiency and expression of the transduced gene in cultures of rAAV‐infected primary chondrocytes and in chondrocytes in the superficial zone of intact articular cartilage. These findings support the concept that UV‐activated gene transduction could be used as an adjuvant for in vivo rAAV articular cartilage gene therapy with low viral titers to prevent and/or treat arthritis.
Efficacy of selective B cell blockade in the treatment of rheumatoid arthritis: Evidence for a pathogenetic role of B cells
Authors: Vita Salvatore De , Zaja Francesco , Sacco Stefania , Candia Alessandro De , Fanin Renato , Ferraccioli Gianfranco
Published: October 2002

Objective

The pathogenetic role of B cells in rheumatoid arthritis (RA) is under debate, but it is currently believed to be marginal. The availability of selective anti–B cell treatment provides a unique opportunity to clarify this issue. This study was undertaken to investigate the effects of B cell blockade in the treatment of refractory RA, and to evaluate the implications with regard to the role of B cells in the disease.

Methods

Five female patients with active, evolving erosive RA were treated with rituximab, an anti‐CD20 chimeric monoclonal antibody. All 5 patients had been nonresponders to combination therapy with methotrexate plus cyclosporin A. Two of the 5 had also failed to respond to anti–tumor necrosis factor α therapy. All of these treatments were discontinued 1 month before institution of anti‐CD20 therapy.

Results

Marked clinical improvement was observed in 2 patients (American College of Rheumatology 70% response [ACR70] and ACR50, respectively), starting at the end of the second month after institution of anti‐CD20 therapy (month 2) and lasting until month 10 in 1 patient (articular relapse) and month 12 in the other (last followup). ACR20 response was observed in 2 additional patients, lasting until month 5 and month 7, respectively (articular relapse in both). Decrease or normalization of serum C‐reactive protein and rheumatoid factor levels were observed in these patients. In contrast, patient 3 had no response to the treatment. RA synovitis and evolving erosive damage were decreased in patients exhibiting a major response, as demonstrated by imaging studies.

Conclusion

Our finding of the clinical efficacy of selective B cell blockade indicates that B cells play a critical role in rheumatoid synovitis, at least in a subset of patients. Qualitative or quantitative differences in B cell commitment in RA pathobiology might have a function in the different responses observed.