bluuebunny/crossref_metadata_2025_split huggingface dataset:
Glycosaminoglycan degradation reduces mineralized tissue–titanium interfacial strength
Authors: Nakamura Hiromi , Shim Jaewoo , Butz Frank , Aita Hideki , Gupta Vijay , Ogawa Takahiro 
Published: February 2006

AbstractAlthough the localization of the proteoglycan/glycosaminoglycan (GAG) complex at the bone–titanium implant interface has been implied, the role of proteoglycans on the establishment of bone–titanium integration is unknown. The hypothesis to be tested was that proteoglycans play an important role in establishing bone–titanium interfacial adhesion. The objective of this study is to investigate the effect of proteoglycan knockdown by GAG enzymatic degradation on the interfacial strength between mineralized tissue and titanium having different surface topographies. Rat bone marrow‐derived osteoblastic cells were cultured on either a machined titanium disk or an acid‐etched titanium disk. At day 21 of culture, one of the three following GAG degradation enzymes was added into the culture; chondroitinase AC, chondroitinase B, or keratanase. After 3 days of incubation (at day 24 of culture), the laser spallation technique was applied to the samples in order to assess the tissue–titanium interfacial strength. In this technique, a laser‐generated stress wave is used to separate the tissue–titanium interface, and the interfacial strength is determined interferometrically by recording the transient free surface velocity of the tissue. Mineralized tissue cultured on the acid‐etched titanium showed 20–30% higher tissue interfacial strength than that cultured on the machined titanium (p < 0.0001). For both the machined and acid‐etched surface cultures, administration of the enzyme reduced the interfacial strength by 25–30% compared with the untreated control cultures (p < 0.0001). There were no differences in the effect among the three different enzymes tested. A nanoindentation study revealed that the enzyme treatment did not affect the elastic modulus of the mineralized tissue. Scanning electron microscopic and energy dispersive spectroscopic analyses revealed less post‐spallation tissue remnant on the titanium substrates when treated with the enzymes. The tissue remnant was greater in amount on the acid‐etched surface than on the machined surface. The results suggest that there exists not only mechanical interlocking but also biological interfacial adhesion between the mineralized tissue and titanium, in which the proteoglycan/GAG complex is involved. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
The effects of titanium and polymethylmethacrylate particles on osteoblast phenotypic stability
Authors: Ramachandran R. , Goodman S.B. , Smith R.L. 
Published: February 2006

AbstractWear particles generated following total joint arthroplasty interact with cells at the periprosthetic margin and induce an inflammatory response that contributes to osteolysis, aseptic loosening, and implant failure. This study examined the long‐term effects of particles from two commonly implanted materials, titanium (Ti) and polymethylmethacrylate (PMMA), on cell viability and metabolism over a 21‐day time course, using the human osteoblast‐like cell line MG‐63. Addition of particles was not associated with increased cell death or nitric oxide production at the particle concentration chosen. Collagen production was increased with exposure to titanium particles, whereas alkaline phosphatase and osteocalcin expression remained unchanged following exposure to both types of particles. The data show that titanium but not PMMA particles shifts bone cell metabolism to preferentially produce fibrous tissue rather than bone. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Immobilized rhBMP‐2/succinylated type I atelocollagen gene expression of intracellular signaling molecules on ST2 cells
Authors: Tsujigiwa Hidetsugu , Nagatsuka Hitoshi , Lee You Jin , Han Phuu Pwint , Gunduz Mehmet , LeGeros Racquel Z. , Inoue Masahisa , Yamada Masao , Nagai Noriyuki 
Published: February 2006

AbstractRecombinant human bone morphogenetic protein‐2 (rhBMP‐2) chemically‐bonded to succinylated type I atelocollagen, a biomaterial carrier with a porous structure, was reported to augment cellular activity of ST2 cells. The Smad protein family has been suggested to play an important role in the intracellular signaling pathway of BMP by its binding to receptors on target cells. However, there has been no study analyzing the downstream genes of the rhBMP‐2 induced intracellular signal transduction pathway. The purpose of this study was to examine the effect of immobilized rhBMP‐2 on gene expression of intracellular signaling molecules on ST2 cells. Our study showed two expression patterns of downstream genes of rhBMP‐2 intracellular signal transduction pathway. In the first pattern, BMPR‐IA, Smad 1, and Smad 5 genes showed high basic expression before the addition of rhBMP, and the high level of gene expression continued for long period and decreased in the late stage when rhBMP‐2 was immobilized. In the second pattern, Smad 6, Smad 7, and Smad 8 genes showed low basic expression before the addition of rhBMP‐2 and a continuous increase from the beginning was followed by a decrease in the late stage when rhBMP‐2 was immobilized. Our results also showed that intracellular signaling continued for prolonged period when rhBMP‐2 was immobilized to succinylated type I atelocollagen. This study indicated that immobilizing rhBMP‐2 is an efficient method to increase bone induction. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
An evaluation of a general circulation model (GCM) and the NCEP–NCAR reanalysis data for winter precipitation in Greece
Authors: Tolika K. , Maheras P. , Flocas H. A. , Arseni‐Papadimitriou A. 
Published: February 2006

AbstractIn this study, an attempt is made to evaluate winter precipitation data derived from the general circulation model (GCM)—HadAM3P (atmospherical circulation model—Hadley Center) and from the National Center for Environmental Prediction–National Center of Atmospheric Research (NCEP–NCAR) reanalysis project for the period 1960–1990. These data sets are compared on a seasonal basis (winter) with observational data derived from stations over Greece. More specifically, the suitability of their average distributions and their spatial and temporal variability is examined. The methods used are principal component analysis (PCA) and canonical correlation analysis (CCA). The connection between the precipitation data sets and five cyclonic circulation types, from a daily catalogue, is also studied. With respect to the spatial distribution of the mean precipitation amounts, NCEP data show better agreement with the observational data compared to the modeled data. However, both NCEP and HadAM3P values are generally underestimated. Moreover, it seems that the HadAM3P is able to capture and reproduce quite satisfactorily the relationship between the precipitation data and the circulation types, but inadequately simulates the impact of orography and the Aegean Sea. Finally, the links between the precipitation variability in Greece and the European 500 hPa variability given by CCA seem to be fairly well reproduced by the model. Copyright © 2006 Royal Meteorological Society
Optimisation and Application of Polyolefin Branch Quantification by Melt‐State 13C NMR Spectroscopy
Authors: Klimke Katja , Parkinson Matthew , Piel Christian , Kaminsky Walter , Spiess Hans Wolfgang , Wilhelm Manfred 
Published: February 2006

AbstractSummary: Quantitative branch determination in polyolefins by melt‐state NMR has been investigated paying particular attention to sensitivity per unit time. Comparison of spectra obtained using spectrometers operating at 700, 500 and 300 MHz 1H Larmor frequency, with 4 and 7 mm MAS probeheads, showed that the best sensitivity was achieved at 500 MHz using a 7 mm 13C1H optimised high‐temperature probehead. For materials available in large quantities static melt‐state NMR, using large‐diameter detection coils at 300 MHz, was shown to produce comparable results to melt‐state MAS measurements in less time. Artificial line broadening, introduced by FID truncation, was reduced by the use of π pulse‐train heteronuclear dipolar‐decoupling. This decoupling method, when combined with a higher duty‐cycle, allowed for the whole FID to be acquired. Optimised methods have been applied to the characterisation of short‐chain branching (SCB) in polyethylene‐ and poly(propylene)‐co‐α‐olefins with varying comonomer incorporation. Long‐chain branch (LCB) concentrations of 8 branches per 100 000 CH2 were quantified for an industrial ‘linear’ polyethylene in 13 h, with a signal‐to‐noise ratio of 10 for the α branch site used. The use of J‐coupling mediated polarisation transfer techniques were also shown to be viable for branch quantification in the melt‐state.An example of the time efficient quantification of very low branch contents in polyethylene using optimised 13C melt‐state NMR under magic‐angle spinning. Concentrations of 7–8 branches per 100 000 CH2 groups were determined in only 13 h.magnified imageAn example of the time efficient quantification of very low branch contents in polyethylene using optimised 13C melt‐state NMR under magic‐angle spinning. Concentrations of 7–8 branches per 100 000 CH2 groups were determined in only 13 h.
Surface Morphology Evolution of a Thin Polymeric Supramolecular Film by Tuning Interactions
Authors: Zhang Ping , Gao Junpeng , Li Binyao , Han Yanchun 
Published: February 2006

AbstractSummary: A polymeric supramolecule consisting of symmetric polystyrene‐block‐poly(4‐vinylpyridine) (PS‐b‐P4VP), dodecylbenzenesulfonic acid (DBSA), and 3‐pentadecylphenol (PDP) was formed by proton transfer and hydrogen bonding. The surface morphology of a thin film of the polymeric supramolecule has been investigated. The spherical PS microdomains embedded in a P4VP(DBSA)1.0(PDP)1.0 matrix are observed for the as‐cast film because the weight fraction, fcomb, of the P4VP(DBSA)1.0(PDP)1.0 blocks is much higher than that of PS as a result of the non‐covalent interactions of P4VP and DBSA and DBSA and PDP. Upon annealing the PS‐b‐P4VP(1:1)(DBSA)1.0(PDP)1.0 film at high temperatures, the hydrogen bonding between the DBSA and PDP diminishes, which leads to a change of overall morphology from an ordered sphere to a pitted structure.AFM topographic image of a PS‐b‐P4VP(1:1)(DBSA)1.0(PDP)1.0 thin film.magnified imageAFM topographic image of a PS‐b‐P4VP(1:1)(DBSA)1.0(PDP)1.0 thin film.
Structural Diversity and Application Potential of Hemicelluloses
Authors: Ebringerová Anna 
Published: February 2006

AbstractIsolation and targeted modification of plant polysaccharides as well as characterization of their structural, molecular and functional properties represent an important research topic of the Institute of Chemistry, Slovak Academy of Sciences, in Bratislava. The presentation provides an overview about the occurrence, structural diversity and functional properties of hemicelluloses representing a diverse group of plant cell wall polysaccharides. They are grouped into xyloglycans, mannoglycans, xyloglucans, and mixed‐linkage β‐glucans. Based on own results as well as on reported data from other research groups, the structure—property relations of the hemicelluloses as well as the existing and potential applications of these polysaccharides are discussed.
Derivatization and Characterization of Xylan from Oat Spelts
Authors: Hettrich Kay , Fischer Steffen , Schröder Nils , Engelhardt Jürgen , Drechsler Ullrich , Loth Fritz 
Published: February 2006

AbstractXylan is the predominant hemicellulose component in the residues of annual plants, e.g., in oat spelts xylan amounts to 35–40% of the total mass. For our investigation xylan was separated through alkaline extraction of oat spelts. Our aim was to synthesize water‐soluble hemicellulose derivatives from oat spelts xylan preferably under heterogeneous conditions. Esterification was used for derivatization. The synthesises were optimised by variation of the temperature, reaction time and the molar ratios to achieve complete solubility, with good reproducibility and in good yields. Other modification possibilities and application areas of xylan from oat spelts could be proved.
Tissue distribution ofN‐acetyltransferase 1 and 2 catalyzing theN‐acetylation of 4‐aminobiphenyl andO‐acetylation ofN‐hydroxy‐4‐aminobiphenyl in the congenic rapid and slow acetylator Syrian hamster
Authors: Hein David W. , Doll Mark A. , Nerland Donald E. , Fretland Adrian J. 
Published: February 2006

AbstractN‐acetyltransferase 1 (NAT1) and 2 (NAT2) enzymes catalyzing both deactivation (N‐acetylation) and activation (O‐acetylation) of arylamine carcinogens such as 4‐aminobiphenyl (ABP) were investigated in a Syrian hamster model congenic at theNAT2 locus. NAT2 catalytic activities (measured withp‐aminobenzoic acid) were significantly (P < 0.001) higher in rapid than slow acetylators in all tissues (except heart and prostate where activity was undetectable in slow acetylators). NAT1 catalytic activities (measured with sulfamethazine) were low but detectable in most tissues tested and did not differ significantly between rapid and slow acetylators. ABPN‐acetyltransferase activity was detected in all tissues of rapid acetylators but was below the limit of detection in all tissues of slow acetylators except liver where it was about 15‐fold lower than rapid acetylators. ABPN‐acetyltransferase activities correlated with NAT2 activities (r2 = 0.871;P < 0.0001) but not with NAT1 activities (r2 = 0.132;P > 0.05). Levels ofN‐hydroxy‐ABPO‐acetyltransferase activities were significantly (P < 0.05) higher in rapid than slow acetylator cytosols for many but not all tissues. TheN‐hydroxy‐ABPO‐acetyltransferase activities correlated with ABPN‐acetyltransferase activities (r2 = 0.695;P < 0.0001) and NAT2 activities (r2 = 0.521,P < 0.0001) but not with NAT1 activities (r2 = 0.115;P > 0.05). The results suggest widespread tissue distribution of both NAT1 and NAT2, which catalyzes bothN‐ andO‐acetylation. These conclusions are important for interpretation of molecular epidemiological investigations into the role ofN‐acetyltransferase polymorphisms in various diseases including cancer. © 2006 Wiley‐Liss, Inc.
Parkinsonism and Parkinson's disease in the elderly: A community‐based survey in Brazil (the Bambuí study)
Authors: Barbosa Maira Tonidandel , Caramelli Paulo , Maia Débora Palma , Cunningham Mauro César Quintão , Guerra Henrique Leonardo , Lima‐Costa Maria Fernanda , Cardoso Francisco 
Published: February 2006

AbstractSeveral community‐based surveys on the prevalence of Parkinsonism and Parkinson's disease have been conducted worldwide, with variations on their methodology and results. The objective of this study is to assess the prevalence of Parkinsonism and its causes in a cohort of individuals age 64 years or older in Bambuí, a Brazilian town. In phase I, 1,186 people older than 64 years responded to a 9‐question screening questionnaire for Parkinsonism. In phase II, all subjects who scored ≥ 2 points on the test were examined independently by at least 2 movement disorder‐trained physicians. A movement disorder senior specialist excluded or confirmed the diagnosis in all suspected cases. The response rate was high for both phases (96% for phase I and 94% for phase II). The prevalence rate per 100 population over 64 years of age in this group was 7.2% for Parkinsonism of all types (n = 86). The most frequent causes were idiopathic Parkinson's disease and drug‐induced Parkinsonism, with prevalence rates of 3.3% (n = 39) and 2.7% (n = 32), respectively. The prevalence of vascular Parkinsonism was 1.1% (n = 13). We found 1 case of posttraumatic Parkinsonism and another with multiple system atrophy. In this first population‐based study of Parkinsonism conducted in Brazil, the prevalence in a cohort of elderly subjects was higher than the observed in other populations worldwide, especially because of the high rates of drug‐induced and vascular Parkinsonism. The prevalence of Parkinson's disease was similar to that observed in elderly people in door‐to‐door surveys in other American, European, and Eastern countries. © 2006 Movement Disorder Society
Local C1 solutions to some non‐linear PDE system
Authors: Callegari Emanuele , Ghisi Marina 
Published: February 2006

AbstractWe prove that the quasilinear initial value problem
equation image
has a unique, local in time, C1 solution, if the matrices Ai are diagonalizable and commute with each other. Copyright © 2006 John Wiley & Sons, Ltd.
Deterministic and statistical methods for reconstructing multidimensional NMR spectra
Authors: Yoon Ji Won , Godsill Simon , Kupče Eriks , Freeman Ray 
Published: February 2006

AbstractReconstruction of an image from a set of projections is a well‐established science, successfully exploited in X‐ray tomography and magnetic resonance imaging. This principle has been adapted to generate multidimensional NMR spectra, with the key difference that, instead of continuous density functions, high‐resolution NMR spectra comprise discrete features, relatively sparsely distributed in space. For this reason, a reliable reconstruction can be made from a small number of projections. This speeds the measurements by orders of magnitude compared to the traditional methodology, which explores all evolution space on a Cartesian grid, one step at a time. Speed is of crucial importance for structural investigations of biomolecules such as proteins and for the investigation of time‐dependent phenomena. Whereas the recording of a suitable set of projections is a straightforward process, the reconstruction stage can be more problematic. Several practical reconstruction schemes are explored. The deterministic methods—additive back‐projection and the lowest‐value algorithm—derive the multidimensional spectrum directly from the experimental projections. The statistical search methods include iterative least‐squares fitting, maximum entropy, and model‐fitting schemes based on Bayesian analysis, particularly the reversible‐jump Markov chain Monte Carlo procedure. These competing reconstruction schemes are tested on a set of six projections derived from the three‐dimensional 700‐MHz HNCO spectrum of a 187‐residue protein (HasA) and compared in terms of reliability, absence of artifacts, sensitivity to noise, and speed of computation. Copyright © 2006 John Wiley & Sons, Ltd.
A multigrid method for anisotropic PDEs in elastic image registration
Authors: Hömke Lars 
Published: February 2006

AbstractThis paper deals with the solution of a non‐linear ill‐conditioned inverse problem arising in digital image registration. In the first part of the paper, we define the problem as the minimization of a regularized non‐linear least‐squares functional, which measures the image difference and smoothness of the transformation. We study inexact Newton methods for solving this problem, i.e. we linearize the functional around a current approximation and replace the Hessian by a suitable operator in order to obtain well‐posed subproblems in each step of the iteration.These anisotropic subproblems are solved using a multigrid solver. Due to the anisotropy in the coefficients of the underlying equations, standard multigrid solvers suffer from poor convergence rates. We discuss modifications to the multigrid components, specifically to the smoothing procedure, the interpolation and the coarse grid correction. Numerical results that demonstrate the improvements obtained with these new components are given. Copyright © 2006 John Wiley & Sons, Ltd.
Effects of sildenafil on pulmonary hypertension and exercise tolerance in severe cystic fibrosis‐related lung disease
Authors: Montgomery Gregory S. , Sagel Scott D. , Taylor Amy L. , Abman Steven H. 
Published: February 2006

AbstractCystic fibrosis (CF) patients with advanced lung disease are at risk for developing pulmonary vascular disease and pulmonary hypertension, characterized by progressive exercise intolerance beyond the exercise‐limiting effects of airways disease in CF. We report on a patient with severe CF lung disease who experienced clinically significant improvements in exercise tolerance and pulmonary hypertension without changing lung function during sildenafil therapy. Pediatr Pulmonol. © 2006 Wiley‐Liss, Inc.
IGF‐I secretion by prostate carcinoma cells does not alter tumor‐bone cell interactions in vitro or in vivo
Authors: Rubin Janet , Fan Xian , Rahnert Jill , Sen Buer , Hsieh Chia‐ling , Murphy Tamara C. , Nanes Mark S. , Horton Lindsay G. , Beamer Wesley G. , Rosen Clifford J. 
Published: February 2006

AbstractBACKGROUNDIGF‐I is an important growth and differentiative factor for osteoblasts and may have a role in defining prostate cancer risk and skeletal metastases.METHODSConditioned media (CM) from human prostate cancer (PC), C4‐2 and C4‐2B, which produce osteoblastic lesions, and PC‐3, which causes osteolysis, was added to MC3T3‐E1 bone cultures. SCID mice were injected intratibially with these engineered cells. Tumor bearing tibiae were analyzed by microCT and pQCT.RESULTSCM from PC cells increased osteoblast proliferation and differentiation and was unaltered by the type of PC cell, IGF‐I antibodies, or exogenous IGF‐I and IGFBP2. Study of intratibial PC tumors in SCID mice showed that C4‐2 cells grew slowly preserving bone structure, while PC‐3 tumors caused rapid osteolysis. Overexpression of IGF‐I did not change either tumor progression or skeletal response.CONCLUSIONSIGF‐I is neither necessary nor sufficient for the osteoblastic response to PC metastases. Prostate © 2006 Wiley‐Liss, Inc.
Expression of BAG‐1 protein correlates with aggressive behavior of prostate cancers
Authors: Krajewska Maryla , Turner Bruce C. , Shabaik Ahmed , Krajewski Stan , Reed John C. 
Published: February 2006

AbstractBackgroundDifferences in tumor behavior, ranging from indolent to aggressive, create a need for novel prognostic biomarkers. BAG‐1 is a co‐chaperone that regulates the activity of Hsp70, Bcl‐2, Raf‐1, growth factor, and steroid receptors (e.g., the Androgen Receptor).MethodsUsing immunohistochemical method, we explored BAG‐1 expression in prostate cancers and its association with clinicopathological parameters.ResultsBAG‐1 immunostaining was elevated in prostate cancer compared to normal prostatic epithelium. Higher nuclear BAG‐1 in hormone‐refractory (n = 34) compared to localized untreated tumors (n = 58) (P < 0.0001) suggested that upregulation of the nuclear isoform may contribute to disease progression. In 64 early‐stage patients (T2N0M0) treated with external‐beam irradiation, cytosolic BAG‐1 correlated with higher pretreatment levels of serum Prostate specific antigen (P = 0.04) and shorter time to disease progression (P = 0.00004).ConclusionsIncreased cytosolic and nuclear BAG‐1 expression may denote more aggressive variants of prostate cancer. Prostate © 2006 Wiley‐Liss, Inc.