bluuebunny/crossref_metadata_2025_split huggingface dataset:
Preparation and characterization of poly‐DL‐lactide–poly(ethylene glycol) microspheres containing λDNA
Authors: Deng Xianmo , Liu Yu , Yuan Minlong , Li Xiaohong , Liu Li , Jia W. X. 
Published: October 2002

AbstractPolylactide (PLA) and a block copolymer, poly‐DL‐lactide–poly(ethylene glycol) (PELA) were synthesized by bulk ring‐opening polymerization initiated by stannous chloride. A linear DNA molecule, λDNA, was used as the model DNA. PLA, PELA, λDNA‐loaded PLA and PELA microspheres were prepared by the solvent‐extraction method based on the formation of multiple w1/o/w2 emulsion. The particle‐size distribution, surface morphology, and DNA loading characterized the microspheres. The mean diameter of λDNA‐loaded PELA microspheres was proved to be 3.5 μm. The integrity of the λDNA molecules, after preparing the microspheres, was determined by agarose gel electrophoresis. The result suggested that most of the λDNA molecules could retain their integrity after being encapsulated by PELA. The PELA microspheres could also prevent λDNA from being degraded by DNase. The in vitro degradation and release of PLA, PELA, and λDNA‐loaded PELA microspheres were carried out in a pH 7.4 buffer solution at 37°C. Quantitatively, evaluating the molecular weight reduction, the mass loss, the particle‐size changes, and the particle‐size distribution changes also monitored the degree of degradation. The release profile was assessed by measurement of the amount of λDNA present in the release medium at determined intervals. The degradation profiles of the PELA microspheres were quite different from those of the PLA microspheres. The introduction of the hydrophilic poly(ethylene glycol) domain in PLA and the presence of λDNA within the microspheres exhibit the apparent influence on the degradation and release profiles. A biphasic release profile was proved, that is, an initial burst release during the first days, then a gradual release. It was demonstrated that the PELA microspheres could be used potentially as a controlled release‐delivery system for λDNA. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2557–2566, 2002
Thermal properties and morphology of noncrosslinking linear low‐density polyethylene‐grafted acrylic acid
Authors: Zhanhai Yao , Ying Gao , Jinghua Yin 
Published: October 2002

AbstractNoncrosslinking linear low‐density polyethylene‐grafted acrylic acid (LLDPE‐g‐AA) was prepared by melt‐reactive extrusion in our laboratory. The thermal behavior of LLDPE‐g‐AA was investigated by using differential scanning calorimetry (DSC). Compared with neat linear low‐density polyethylene (LLDPE), melting temperature (Tm) of LLDPE‐g‐AA increased a little, the crystallization temperature (Tc) increased about 4°C, and the melting enthalpy (ΔHm) decreased with an increase in acrylic acid content. Isothermal crystallization kinetics of LLDPE and LLDPE‐g‐AA samples were carried out by using DSC. The overall crystallization rate of LLDPE was smaller than that of grafted samples. It showed that the grafted acrylic acid monomer onto LLDPE acted as a nucleating agent. Crystal morphologies of LLDPE‐g‐AA and LLDPE were examined by using SEM. Spherulite sizes of LLDPE‐g‐AA samples were lower than that of LLDPE. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2626–2630, 2002
Electrochemistry of the films of a novel class C60 covalently linked PPV derivative: Electrochemical quartz crystal microbalance study in acetonitrile solutions of tetra‐n‐butylammonium cations
Authors: Liu Ying , Fan Louzhen , Li Yongfang , Xiao Shengxiong , Li Yuliang 
Published: October 2002

AbstractThe electrochemical behaviors of a novel class C60 covalently linked PPV derivatives (i.e., PPV‐1‐C60 and PPV‐2‐C60) in thin solid films as well as in solutions are reported. The first cathodic peak potentials of PPV‐1‐C60 and PPV‐2‐C60 have positive shifts by 30 and 50 mV, respectively, compared to pristine C60 in formal cyclic voltammetry (CV). Simultaneous CV and piezoelectric microgravimetry of the drop‐coated thin solid films of PPV‐1‐C60 and PPV‐2‐C60 in acetonitrile solutions of TBA+ counteractions are strongly influenced by the structure of the polymer‐C60, including the length of the chain macromolecule and the steric hindrance effect. In addition, the atomic force microscopy (AFM) images of PPV‐1‐C60 and PPV‐2‐C60 films deposited on Au/quartz electrode both exhibit even distribution. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2737–2741, 2002
Phase behavior and density of polysulfone in binary fluid mixtures of tetrahydrofuran and carbon dioxide under high pressure: Miscibility windows
Authors: Zhang Wei , Kiran Erdogan 
Published: October 2002

AbstractMixtures of tetrahydrofuran (THF) and carbon dioxide (CO2) were identified as new solvent systems for polysulfone. The miscibility and density of polysulfone in binary fluid mixtures of THF and CO2 were investigated from 300 to 425 K at pressures up to 70 MPa. The influence of the CO2 and polysulfone concentrations was studied, with the concentrations of the other two components kept constant. At a 4.5 wt % polymer concentration, the demixing pressures in a 10 wt % CO2 and 90 wt % THF mixture increased with temperature (310–425 K) from 15 to 40 MPa. With increasing CO2 concentration (from ca. 10 to 14 wt %), a significant increase (from 15 to 70 MPa at 310 K) was observed in the demixing pressures. Furthermore, with an increasing amount of CO2, the nature of the phase boundary shifted from lower critical solution temperature behavior to upper critical solution temperature behavior. The influence of the polymer concentration was studied in the 0–5 wt % range at two CO2 levels, with solvent compositions of 10 wt % CO2 and 90 wt % THF and 13 wt % CO2 and 87 wt % THF. The system with a higher level of CO2 (13 wt %) showed highly unusual phase behavior: on pressure–composition and temperature–composition diagrams, the system displayed two distinct regions of miscibility. In the system with 10 wt % CO2, the distinct regions of miscibility that were observed in the system with 13 wt % CO2 partially overlapped and led to a W‐shape phase boundary. The densities of the polymer solutions were measured from the one‐phase region through the demixing point into the two‐phase region at a constant temperature. No significant change in density was found around the phase boundary; this indicated that the coexisting phases had similar densities, as is often the case with liquid–liquid phase separation in polymer solutions under high pressure. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2357–2362, 2002
Proton‐conductive membranes of sulfonated polyphenylsulfone
Authors: Dyck A. , Fritsch D. , Nunes S. P. 
Published: October 2002

AbstractPolyphenylsulfone was sulfonated by two different methods: reaction with SO3 and reaction with (CH3)3SiSO3Cl. The products were characterized, and the advantages of both methods are discussed. Much more homogeneous products were obtained from the reaction with (CH3)3SiSO3Cl, along with better control of the sulfonation degree. An alternative method of membrane preparation led to an asymmetric structure, which allowed the combination of high mechanical stability and high proton conductance. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 86: 2820–2827, 2002
Epitope‐specific recognition of type II collagen by rheumatoid arthritis antibodies is shared with recognition by antibodies that are arthritogenic in collagen‐induced arthritis in the mouse
Authors: Burkhardt Harald , Koller Tobias , Engström Åke , Nandakumar Kutty Selva , Turnay Javier , Kraetsch Hans G. , Kalden Joachim R. , Holmdahl Rikard 
Published: October 2002

AbstractObjectiveTo analyze the fine specificity of IgG autoantibodies in sera from rheumatoid arthritis (RA) patients for type II collagen (CII) epitopes that are arthritogenic in collagen‐induced arthritis (CIA), a relevant murine model of RA.MethodsFor enzyme‐linked immunosorbent assay (ELISA) analysis of conformation‐dependent autoantibody binding, recombinant chimeric collagens that harbor the respective CII epitopes as an insertion within the frame of a constant type X collagen triple helix were constructed. In addition, synthetic peptides mimicking the native collagen structures were applied for the first time in the ELISA assessment of humoral CII autoimmunity.ResultsThe pathogenicity of IgG responses to certain CII determinants in CIA was demonstrated by arthritis development in BALB/c mice upon the combined transfer of 2 mouse monoclonal antibodies specific for precisely mapped conformational CII epitopes (amino acid residues 359–369 [C1III] and 551–564 [J1]), whereas antibodies to another epitope (F4) were not arthritogenic. To test whether human autoimmune responses are similarly directed to these conserved CII determinants, serum IgG was analyzed. The prevalence of sera with increased IgG binding to the C1III epitope was significantly higher in RA compared with sera from healthy donors or from patients with other rheumatic conditions, e.g., osteoarthritis (OA), systemic lupus erythematosus (SLE), or relapsing polychondritis (RP), whereas levels of antibodies specific for the nonarthritogenic F4 epitope were associated with OA rather than RA.ConclusionAutoimmunity to CII, although detectable in different rheumatic conditions, differs in fine specificity between distinct disease entities. In RA, in contrast to degenerative joint disease, RP, and SLE, autoantibody responses are directed to an evolutionary conserved CII structure that is also targeted by pathogenic autoimmune responses in murine models of arthritis.
The insulin‐like growth factor binding proteins in uncultured human cartilage: Increases in insulin‐like growth factor binding protein 3 during osteoarthritis
Authors: Morales Teresa I. 
Published: October 2002

AbstractObjectiveTo assess changes in the insulin‐like growth factor binding proteins (IGFBPs) in uncultured cartilage during stages of osteoarthritis (OA), and to determine if OA cartilage is capable of autocrine secretion of IGFBPs.MethodsArticular cartilage was dissected from fibrillated and nonfibrillated sites of 11 human femoral heads, and extracted in buffer containing 8M urea. IGFBPs were identified by immunoprecipitation and subsequent analysis by 125I–IGF‐2 Western ligand blotting (WLB), radioimmunoassay, or 2‐site immunoradiometric assay (IRMA). IGFBPs were assessed in cartilage extracts by WLB. IGFBP‐3 content was determined by IRMA and synthesis by metabolic labeling with 35S‐cysteine in organ cultures.ResultsSample grouping into 3 distinct OA strata was supported by gross pathology of the femoral heads, histologic grading of cartilage slices, and biochemical analysis of the glycosaminoglycan and protein content of the extracts. Group I was normal/mild OA, group II was intermediate OA, and group III was severe OA. IGFBP‐2 was present in all samples, IGFBP‐4 in sporadic samples, and BP‐3 in group II–III samples. By IRMA, group I had a mean ± SD of 6.26 ± 2.6 ng IGFBP‐3/mg soluble protein (IGFBP‐3) (n = 6), group II had a mean ± SD 14 ± 7.5 IGFBP‐3 (n = 10), and group III had a mean ± SD 17.03 ± 8.94 IGFBP‐3 (n = 6). Analysis of variance showed group differences (F[3,19] = 3.84, P = 0.04), and post hoc tests revealed that IGFBP‐3 levels were higher for group III versus group I (P = 0.04). OA cartilage synthesized IGFBP‐3.ConclusionIncreases in net cartilage content of IGFBP‐3 occurred in intact OA cartilage, reaching statistically significant elevation in severe disease. There was autocrine IGFBP‐3 production in OA cartilage.
Lectin‐like oxidized low‐density lipoprotein receptor 1 mediates leukocyte infiltration and articular cartilage destruction in rat zymosan‐induced arthritis
Authors: Nakagawa Takefumi , Akagi Masao , Hoshikawa Hajime , Chen Mingyi , Yasuda Tadashi , Mukai Shogo , Ohsawa Kunitaka , Masaki Tomoh , Nakamura Takashi , Sawamura Tatsuya 
Published: October 2002

AbstractObjectiveThe relationship between rheumatoid arthritis and atherosclerosis has been recognized for >20 years. This study aimed to elucidate the roles of oxidized low‐density lipoprotein (ox‐LDL; one of the main pathogenic factors of atherosclerosis) and its endothelial receptor, lectin‐like ox‐LDL receptor 1 (LOX‐1), in arthritic joints using a rat zymosan‐induced arthritis (ZIA) model.MethodsLOX‐1 expression and ox‐LDL accumulation in arthritic joints were detected by immunohistochemistry using specific mouse anti–LOX‐1 and anti–ox‐LDL monoclonal antibodies, respectively. To elucidate the effects of the expressed LOX‐1 on arthritis, ZIA rats were treated with anti–LOX‐1 antibody or normal mouse IgG. The severity of arthritis was analyzed by joint swelling. Cell infiltration, synovial hyperplasia, and proteoglycan losses were also determined by histologic scoring. Proinflammatory cytokine and nitrite levels in serum and joint fluid were also measured.ResultsImmunohistochemical study of ZIA demonstrated LOX‐1 expression on synovial endothelium and postcapillary venules at 6 hours after the induction of inflammation, with maximum expression detected at 24 hours. LOX‐1 was also expressed weakly on both joint cartilage and synovium. Ox‐LDL, a ligand of LOX‐1, was also detected in articular chondrocytes. Administration of anti–LOX‐1 antibody, which blocks LOX‐1 activity, suppressed joint swelling (by 33.5%), leukocyte infiltration, and joint nitrite accumulation at 24 hours, as well as cartilage destruction at 7 days, compared with control rats.ConclusionLOX‐1 induction in arthritic joints might play a role in promoting joint inflammation and cartilage destruction by mediating leukocyte infiltration into the arthritic joints of ZIA rats.
A re‐examination of melioration and rational choice
Authors: Tunney Richard J. , Shanks David R. 
Published: October 2002

AbstractWe examined how people allocate choices between two alternatives when the payoff from each alternative varied as a function of the allocation of recent choices. On any one trial alternative A had a higher immediate payoff than alternative B, but across all trials B had a higher overall payoff than A. Rational choice theory requires that participants allocate all their responses to the alternative with the greatest overall payoff irrespective of which has the higher immediate payoff. Melioration, in contrast, proposes that participants are motivated to choose the alternative with the higher immediate payoff, irrespective of the consequences for future returns. We report four experiments in which we varied the nature of the payoffs. Participants exhibited self‐control consistent with rational choice theory when payoffs varied in magnitude, but exhibited impulsiveness consistent with melioration when the payoffs varied in probability. Finally, we show that impulsivity when payoffs varied in probability can be overcome following un‐reinforced practice. Copyright © 2002 John Wiley & Sons, Ltd.
Mushroom stem cells
Authors: Money Nicholas P. 
Published: October 2002

AbstractContrary to the rarity of totipotent cells in animals, almost every cell formed by a fungus can function as a “stem cell”. The multicellular fruiting bodies of basidiomycete fungi consist of the same kind of filamentous hyphae that form the feeding phase, or mycelium, of the organism, and visible cellular differentiation is almost nonexistent. Mushroom primordia develop from masses of converging hyphae, and the stipe (or stem), cap, and gills are clearly demarcated within the embryonic fruiting body long before the organ expands and unfolds through water uptake and cell wall loosening.aThough frequent references are made to gilled mushrooms in this article, the totipotent nature of fruiting body cells and lack of meristems is also applicable to basidiomycetes that spread their spore‐producing tissues inside tubes (e.g., boletes), over spines and rippled surfaces, or form spores in cavities within the fruiting body.
Even in the mature mushroom, every hypha retains its totipotency. Among animals, only sponges exhibit a similar degree of developmental flexibility, which is interesting, because these simple metazoans may be relatively close relatives of fungi. BioEssays 24:949–952, 2002. © 2002 Wiley Periodicals, Inc.
Increasingly complex: New players enter the Wnt signaling network
Authors: Pandur Petra , Maurus Daniel , Kühl Michael 
Published: October 2002

AbstractWnt proteins can activate different intracellular signaling cascades in various organisms by interacting with receptors of the Frizzled family. The first identified Wnt signaling pathway, the Wnt/β‐catenin pathway, has been studied in much detail and is highly conserved among species. As to non‐canonical Wnt pathways, the current situation is more nebulous partly because the intracellular mediators of this pathway are not yet fully understood and, in some cases, even identified. However, there are increasing data that prove the existence of non‐canonical Wnt signaling and demonstrate its involvement in different developmental processes. In vertebrates, Wnt‐11 and Wnt‐5A can activate the Wnt/JNK pathway, which resembles the planar cell polarity pathway in Drosophila. The Wnt/Ca2+‐pathway has only been described in Xenopus and zebrafish so far and it is unclear whether it also exists in other organisms. Two recent papers provide us with new insight into non‐canonical Wnt signaling by (1) presenting a new intracellular mediator of non‐canonical signaling in Xenopus1 and (2) implicating the existence of an additional non‐canonical Wnt signaling pathway in flies.2 BioEssays 24:881–884, 2002. © 2002 Wiley Periodicals, Inc.
Novel strategies for targeting the dimerization interface of HIV protease with cross‐linked interfacial peptides
Authors: Bowman Michael J. , Chmielewski Jean 
Published: October 2002

AbstractAs the prevalence of AIDS continues to grow, and current therapeutic agents begin to lose efficacy, the need for alternative treatments to combat HIV has become significantly greater. Targeting the highly conserved dimerization interface of HIV protease (PR) with interfacial peptides has been shown to reduce the activity of the enzyme due to generation of inactive monomers. The potency of these peptide‐based inhibitors has been dramatically increased by cross‐linking the interfacial sequences derived from HIV PR. This review focuses on a variety of strategies to develop potent, low‐molecular‐weight dimerization inhibitors of HIV PR. © 2002 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 66: 126–133, 2002
Inhibition of proteolysis and other posttranslational modifications with substrate‐targeted inhibitors
Authors: Kodadek Thomas 
Published: October 2002

AbstractThis article reviews the concept of developing protease inhibitors that target the substrate polypeptide rather than the enzyme. Substrate‐targeted inhibitors have the potential to be more specific than even the most highly selective enzyme‐targeted inhibitors because essentially all proteases process multiple substrates. The challenge in developing substrate‐targeted protease inhibitors centers on the development of high‐affinity binding agents for short stretches of amino acids (linear epitopes). Recent experimental progress toward this goal and a number of other potential solutions are discussed. © 2002 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 66: 134–140, 2002
Ethics issues in security hospitals
Authors: Weinstein Henry C. 
Published: October 2002

AbstractThe term ‘security hospital’ is used for a variety of facilities including forensic hospitals and prison hospitals, which, because of their mission, the nature of their work, and the populations they serve—or because of the authority under which they operate—place the staff at considerable risk of ethical violations related to either clinical care or to forensic activities. The problem of divided loyalties is of special concern in security hospitals. Ethics principles particularly at risk are confidentiality and informed consent. Where there are cultural disparities between the staff and the patients, differences in background, socioeconomic class, education, and other types of diversity, cultural awareness is required and must be reflected in appropriate treatment and evaluation. To counteract the risks of ethical violations, a security hospital should create an ethical climate and develop means to anticipate, prevent, and deal with ethical violations. These might include detailed and specific policies and procedures, programs of orientation, education, consultation, and liaison as well as its own ethics committee. Copyright © 2002 John Wiley & Sons, Ltd.
Safeguarding disabled children in residential settings: what we know and what we don't know
Authors: Paul Alina , Cawson Pat 
Published: October 2002

AbstractResearch in America, Canada, Australia and Britain has revealed that disabled children are particularly vulnerable to abuse. Their likelihood of attending residential institutions, their dependency on others for personal care and the lack of opportunities for them to alert others to maltreatment or comprehend the nature of abusive acts all increase levels of risk. Over the last decade, there has been increasing public and professional concern about the abuse of children in residential establishments, resulting in a number of inquiries. However, the abuse of disabled children in residential settings has received little attention. Despite residential schools, care homes and respite care being widely used by disabled children, there is a paucity of knowledge regarding the standards of child protection in these establishments. This article explores the research literature revealing the vulnerability of disabled children to abuse when living away from home, what measures can be taken to help protect them and the limitations of available data as a basis for planning child protection measures. Copyright © 2002 John Wiley & Sons, Ltd.
Early changes in coronary flow physiology after balloon angioplasty or stenting: A 24‐hour Doppler flow velocity study
Authors: Dupouy Patrick , Aptecar Eduardo , Pelle Gabriel , Boudali Lotfi , Teiger Emmanuel , Lanoue Isabelle , Veyssière F. , Garot Philippe , Pernès Jean Marc , Hovasse Thomas , Kern Morton J. , Randé Jean Luc Dubois 
Published: October 2002

AbstractTo evaluate early changes in myocardial microcirculation after balloon or stent coronary angioplasty, we studied 57 patients undergoing coronary angioplasty with a Doppler‐tipped guidewire, with (n = 26) or without stenting. Postprocedural quantitative coronary angiography and coronary flow velocity were measured after 10 min and 24 hr. As compared to stenting, no stenting was associated with a higher postprocedural stenosis rate (21% ± 13% vs. 12% ± 10%; P < 0.05), smaller coronary velocity reserve (CVR; 2.2 ± 0.4 vs. 2.5 ± 0.7; P = 0.04), and smaller relative CVR (0.8 ± 0.2 vs. 1.1 ± 0.3; P = 0.001). At 24 hr, CVR and relative CVR in the unstented group increased to the level in the stented group, mainly because of a decrease in basal average peak velocity (APV). Overall, there was a significant negative linear relation between CVR and APV variations during the 24‐hr period. In the subgroups with persistent abnormalities, CVR variation was closely related to the basal APV/reference APV ratio. In conclusion, coronary reserve normalization can occur within 24 hr after coronary angioplasty and is closely dependent on postangioplasty APV. Myocardial distal resistances should be considered when interpreting postangioplasty CVR. Cathet Cardiovasc Intervent 2002;57:191–198. © 2002 Wiley‐Liss, Inc.