bluuebunny/crossref_metadata_2025_split huggingface dataset:
Interactions between self‐assembled polyelectrolyte shells and tumor cells
Authors: Ai Hua , Pink John J. , Shuai Xintao , Boothman David A. , Gao Jinming 
Published: April 2005

AbstractLayer‐by‐layer self‐assembled polyelectrolyte shells are a new class of micro/nanocapsules with unique physicochemical properties for potential applications in drug/gene delivery. The objective of this study was to investigate the interactions of polyelectrolyte shells (∼1 μm in diameter) with MCF‐7 breast cancer cells and identify key parameters that affect such interactions. Tailoring of surface properties of polyelectrolyte shells was achieved by choosing different outermost layer materials, including cationic polymers, anionic polymers, and lipid bilayers. Different surface compositions led to a wide range of electrostatic potentials from −46 to +47 mV in phophate‐buffered saline buffer. Confocal microscopy studies showed that the polyelectrolyte shells were internalized into the cell cytoplasm, but not into the nuclei. Correlation of cell uptake with shell surface compositions was complicated by the adsorption of serum proteins on the surface of polyelectrolyte shells, particularly polycation‐coated shells. To prevent protein adsorption, poly(ethylene glycol) (PEG) grafted poly(ethyleneimine) (PEI) copolymers (1:1, 1:5, 1:10 graft ratios) were synthesized and introduced on the shell surface. Shells coated with PEI‐PEG copolymers effectively reduced protein adsorption whereas PEI‐PEG copolymers with lower graft ratios achieved higher cell uptake efficiency after 24 h of incubation with MCF‐7 cells. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res 73A: 303–312, 2005
Analysis of glutathione and immunoglobulin G inside chromatographic beads using surface‐enhanced Raman scattering spectroscopy
Authors: Larsson Mina , Lindgren Jan 
Published: April 2005

AbstractGold‐containing chromatographic beads were used to record spectra of the tripeptide glutathione and the protein immunoglobulin G (IgG) by surface‐enhanced Raman scattering (SERS) spectroscopy. SERS spectra were recorded from glutathione in solution at three different pH values, 2, 6 and 10. It was found that the SERS spectra are strongly dependent on pH, which indicates that the adsorption mode of glutathione changes with the pH value of the solution. Assignment of some of the observed bands and a suggestion for adsorption modes at the different pH were made. A SERS spectrum of human IgG in ethanolamine was also recorded. No complete assignment of the bands in this spectrum was performed, but the results indicate adsorption to the gold nanoparticles by aromatic amino acids and cystine residues. Copyright © 2005 John Wiley & Sons, Ltd.
Molecular imprinting technology in capillary electrochromatography
Authors: Turiel Esther , Martin‐Esteban Antonio 
Published: April 2005

AbstractMolecularly imprinted polymers (MIPs) are tailor‐made synthetic polymers with a predetermined selectivity for a given analyte, or group of structurally related compounds, that make them ideal materials for use as stationary phases in affinity chromatography. However, extensive peak broadening and tailing, especially of the more retained compound (normally the template) are often observed. Thus, huge efforts have been made during recent years to use MIPs in capillary electrochromatography, which is inherently a more efficient chromatographic technique than conventional HPLC. Accordingly, this paper gives an overview of the attempts carried out in the recent past to improve the chromatographic performance of MIPs in capillary electrochromatography as well as more recent applications. It is concluded that MIPs are very promising materials for use as selective stationary phases in CEC.
Spectral and dynamical properties of random models with nonlocal and singular interactions
Authors: Hislop Peter D. , Kirsch Werner , Krishna M. 
Published: April 2005

AbstractWe give a spectral and dynamical description of certain models of random Schrödinger operators onL2(ℝd) for which a modified version of the fractional moment method of Aizenman and Molchanov [3] can be applied. One family of models includes Schrödinger operators with random nonlocal interactions constructed from multidimensional wavelet bases. The second family includes Schrödinger operators with random singular interactions randomly located on sublattices of ℤd, ford= 1, 2, 3. We prove that these models are amenable to Aizenman‐Molchanov‐type analysis of the Green's function, thereby eliminating the use of multiscale analysis. The basic technical result is an estimate on the expectation of fractional moments of the Green's function. Among our results, we prove a Wegner estimate, Hölder continuity of the integrated density of states, and spectral and Hilbert‐Schmidt dynamical localization at negative energies. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Bases and quasi‐reflexivity in Fréchet spaces
Authors: Valdivia Manuel 
Published: April 2005

AbstractA Fréchet space E is quasi‐reflexive if, either dim(E″/E) < ∞, or E″[β(E″,E′)]/E is isomorphic to ω. A Fréchet space E is totally quasi‐reflexive if every separated quotient is quasi‐reflexive. In this paper we show, using Schauder bases, that E is totally quasi‐reflexive if and only if it is isomorphic to a closed subspace of a countable product of quasi‐reflexive Banach spaces. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On a class of Besicovitch functions to have exact box dimension: A necessary and sufficient condition
Authors: Zhou S. P. , He G. L. 
Published: April 2005

AbstractLet 1 < s < 2, λk > 0 with λk → ∞ satisfy λk+1/λk ≥ λ > 1. For a class of Besicovich functions B(t) = $ \sum ^{\infty} _{k=1} \, \lambda ^{s-2} _{k} $ sin λkt, the present paper investigates the intrinsic relationship between box dimension of their graphs and the asymptotic behavior of {λk}. We show that the upper box dimension does not exceed s in general, and equals to s while the increasing rate is sufficiently large. An estimate of the lower box dimension is also established. Then a necessary and sufficient condition is given for this type of Besicovitch functions to have exact box dimensions: for sufficiently large λ, dimBΓ(B) = dimBΓ(B) = s holds if and only if limn→∞ $ { { {\rm log} \lambda _{n+1}} \over { {\rm log} \lambda _{n} } } $ = 1. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Visual system side effects caused by parasympathetic dysfunction after botulinum toxin type B injections
Authors: Dubow Jordan , Kim Angela , Leikin Jerrold , Cumpston Kirk , Bryant Sean , Rezak Michael 
Published: April 2005

AbstractBotulinum toxin type B (BTX‐B) has been approved by the Food and Drug Administration for the treatment of cervical dystonia. However, as with botulinum toxin type A (BTX‐A) it has off‐label uses, such as for hyperhidrosis, focal dystonias, spasticity, and facial wrinkles. BTX‐B has also been shown to be a safe and effective alternative for patients who are resistant to BTX‐A. The most commonly reported side effects include dry mouth and dysphagia. To date, there have been few reports of visual disturbances associated with BTX‐B use. In this study, we report on three individual patients who received BTX‐B and who subsequently developed parasympathetic dysfunction of the visual system after injections of BTX‐B at remote sites. © 2005 Movement Disorder Society
Impact of pro‐oxidant agents on the morula‐blastocyst transition in bovine embryos
Authors: Feugang Jean‐Magloire , Donnay Isabelle , Mermillod Pascal , Marchandise Joelle , Lequarre Anne‐Sophie 
Published: April 2005

AbstractExposing day 5 bovine morulae to reactive oxygen species induces a delayed degeneration of some blastocysts on day 8 post‐insemination (pi) but without affecting the blastocyst rates. The aim of this study was to characterize the resisting and the degenerating population of blastocysts. The kinetics of degeneration of the embryos exposed to the two pro‐oxidant agents: 2,2′‐azobis (2‐amidinopropane) dihydrochloride (AAPH) and buthionine sulfoximine (BSO) was evaluated using time‐lapse cinematography. With both agents the first signs of degeneration appeared at day 7.5 pi but the duration of the degeneration process was shorter in presence of AAPH than BSO (4.2 vs. 12.5 hr, ANOVA, P < 0.05). The resisting blastocysts derived from morulae with a larger diameter (mean diameter: 161 vs. 154 μm, ANOVA, P < 0.05) and showed an earlier cavitation (135 vs. 142 hpi, P < 0.05) than the degenerating ones. The profile of protein neosynthesis at day 7 was not affected by the treatment. The proportion of male embryos was more important in the resisting than in the degenerating population (70 vs. 55%, χ2, P < 0.05) especially when the stress was induced by AAPH. The quality of the resisting embryos, measured by the total cell number and the rate of apoptosis, did not seem to be affected when compared to control embryos. In conclusion, resistance to oxidative stress seems related to the kinetics of development and/or the sex of the embryos. Resisting embryos apparently display a quality similar to untreated embryos. Mol. Reprod. Dev. © 2005 Wiley‐Liss, Inc.
Effects of duration, concentration, and timing of ionomycin and 6‐dimethylaminopurine (6‐DMAP) treatment on activation of goat oocytes
Authors: Lan Guo‐Cheng , Han Dong , Wu Yan‐Guanng , Han Zheng‐Bin , Ma Suo‐Feng , Liu Xin‐Yong , Chang Chong‐Le , Tan Jing‐He 
Published: April 2005

AbstractThe protocol of ionomycin followed by 6‐dimethylaminopurine (6‐DMAP) is commonly used for activation of oocytes and reconstituted embryos. Since numerous abnormalities and impaired development were observed when oocytes were activated with 6‐DMAP, this protocol needs optimization. Effects of concentration and treatment duration of both drugs on activation and development of goat oocytes were examined in this study. The best oocyte activation (87–95%), assessed by pronuclear formation, was obtained when oocytes matured in vitro for 27 hr were treated with 0.625–20 μM ionomycin for 1 min before 6‐hr incubation in 2 mM 6‐DMAP. Progressional reduction of time for 6‐DMAP‐exposure showed that the duration of 6‐DMAP treatment can be reduced to 1 hr from the second up to the fourth hour after ionomycin, to produce activation rates greater than 85%. Activation rates of oocytes in vitro matured for 27, 30, and 33 hr were higher (P < 0.05) than that of oocytes matured for 24 hr when treated with ionomycin plus 1‐hr (the third hour) 6‐DMAP, but a 4‐hr incubation in 6‐DMAP enhanced activation of the 24‐hr oocytes. Goat activated oocytes began pronuclear formation at 3 hr and completed it by 5‐hr post ionomycin. An extended incubation in 6‐DMAP (a) impaired the development of goat parthenotes, (b) quickened both the release from metaphase arrest and the pronuclear formation, and (c) inhibited the chromosome movement at anaphase II (A‐II) and telophase II (T‐II), leading to the formation of one pronucleus without extrusion of PB2. In conclusion, duration, concentration, and timing of ionomycin and 6‐DMAP treatment had marked effects on goat oocyte activation, and to obtain better activation and development, goat oocytes matured in vitro for 27 hr should be activated by 1 min exposure to 2.5 μM ionomycin followed by 2 mM 6‐DMAP treatment for the third hour. Mol. Reprod. Dev. © 2005 Wiley‐Liss, Inc.
Involvement of superficial peroneal sensory nerve in common peroneal neuropathy
Authors: Kang Peter B. , Preston David C. , Raynor Elizabeth M. 
Published: April 2005

AbstractMotor involvement in common peroneal neuropathy (CPN) frequently shows a selective pattern with regard to deep and superficial divisions of the peroneal nerve, by clinical examination and needle electromyography. The involvement of the sensory branch of the superficial peroneal nerve (SPN) has not been well established using nerve conduction studies. Among 42 cases of electrophysiologically defined CPN in 35 patients, 37 (88%) had clinical or electrophysiologic evidence for SPN involvement, but only 20 had diminished superficial peroneal sensory response (SPSR) amplitudes. Many of the cases involving normal SPSRs had significant axonal loss involving deep peroneal motor fibers. Sparing of the superficial peroneal sensory fibers provides further evidence for the selective vulnerability of different nerve fascicles to injury. This is an important pattern to recognize; from a practical standpoint, focal segmental conduction abnormalities in the motor nerve and EMG findings can help to differentiate these lesions from L‐5 radiculopathy. Muscle Nerve 31, 2005
Beta 2 adrenergic receptor polymorphisms in cystic fibrosis
Authors: Hart Meeghan A. , Konstan Michael W. , Darrah Rebecca J. , Schluchter Mark D. , Storfer‐Isser Amy , Xue Lintong , Londono Douglas , Goddard Katrina A.B. , Drumm Mitchell L. 
Published: April 2005

AbstractThere has been a recent emphasis on identifying modifier genes that influence the severity of cystic fibrosis (CF) lung disease. The beta‐2‐adrenergic receptor is expressed on airway smooth muscle, is the target for inhaled beta agonists, and has several common polymorphisms in its gene, ADRB2. Polymorphisms changing glycine to arginine or glutamate to glutamine in codons 16 and 27, respectively, were associated with differences in clinical response to inhaled beta agonists in individuals with asthma. We compared acute airway responsiveness and 5‐year decline in pulmonary function in CF patients with different ADRB2 genotypes. One hundred and six subjects performed spirometry before and after the administration of an inhaled bronchodilator, and had ADRB2 genotype determined for codons 16 and 27. Comparing the percent change in FEV1 and FEF25–75 continuously revealed differences in the degree of airway responsiveness to bronchodilator between ADRB2‐genotyped groups. However, there was no significant relationship between the ADRB2 genotype at positions 16 and 27 and bronchodilator response when defined as 12% improvement in FEV1. Five‐year decline in percent predicted FEV1 showed no association with ADRB2 genotype. These data are consistent with variants of the ADRB2 gene having different responses to bronchodilator, but the long‐term effects, if any, are not apparent over a 5‐year period. Pediatr Pulmonol © 2005 Wiley‐Liss, Inc.
Investigation of limiting metabolic steps in the utilization of xylose by recombinant Saccharomyces cerevisiae using metabolic engineering
Authors: Karhumaa Kaisa , Hahn‐Hägerdal Bärbel , Gorwa‐Grauslund Marie‐F. 
Published: April 2005

AbstractA Saccharomyces cerevisiae screening strain was designed by combining multiple genetic modifications known to improve xylose utilization with the primary objective of enhancing xylose growth and fermentation in xylose isomerase (XI)‐expressing strains. Strain TMB 3045 was obtained by expressing the XI gene from Thermus thermophilus in a strain in which the GRE3 gene coding for aldose reductase was deleted, and the genes encoding xylulokinase (XK) and the enzymes of the non‐oxidative pentose phosphate pathway (PPP) [transaldolase (TAL), transketolase (TKL), ribose 5‐phosphate ketol‐isomerase (RKI) and ribulose 5‐phosphate epimerase (RPE)] were overexpressed. A xylose‐growing and fermenting strain (TMB 3050) was derived from TMB 3045 by repeated cultivation on xylose medium. Despite its low XI activity, TMB 3050 was capable of aerobic xylose growth and anaerobic ethanol production at 30 °C. The aerobic xylose growth rate reached 0.17 l/h when XI was replaced with xylose reductase (XR) and xylitol dehydrogenase (XDH) genes expressed from a multicopy plasmid, demonstrating that the screening system was functional. Xylose growth had not previously been detected in strains in which the PPP genes were not overexpressed or when overexpressing the PPP genes but having XR and XDH genes chromosomally integrated. This demonstrates the necessity to simultaneously increase the conversion of xylose to xylulose and the metabolic steps downstream of xylulose for efficient xylose utilization in S. cerevisiae. Copyright © 2005 John Wiley & Sons, Ltd.
Estimation of aboveground biomass and net biomass increment in a cool temperate forest on a landscape scale
Authors: Hiura Tsutom 
Published: April 2005

AbstractI clarified aboveground biomass (AGB), net biomass increment (NBI) and its spatial heterogeneity in a cool temperate forest on a landscape scale (>2,200 ha). The relationships among AGB, NBI, and the size frequency distribution of trees of each stand were examined by combining an analysis of vegetation using aerial photographs, and data from 146 inventory plots (28.8 ha in total). This area included natural broad‐leaved stands, harvested broad‐leaved stands, and artificial conifer plantations. A −3/2 power distribution density function was applied to the individual mass frequency distribution of each plot. Estimated AGB in carbon (C) equivalent was 480–5,615 g C m−2 (3,130 g C m−2 on average), and NBI was −98 to 436 g C m−2 year−1 (83.0 g C m−2 year−1 on average). NBI had a single significant relationship with the reciprocal of theoretical maximum individual mass, while NBI was not significantly related to AGB. My results showed that, on a landscape scale, AGB and NBI strongly depend on the size structure of forest stands.
The crystal structure of a partial mouse Notch‐1 ankyrin domain: Repeats 4 through 7 preserve an ankyrin fold
Authors: Lubman Olga Y. , Kopan Raphael , Waksman Gabriel , Korolev Sergey 
Published: April 2005

AbstractFolding and stability of proteins containing ankyrin repeats (ARs) is of great interest because they mediate numerous protein–protein interactions involved in a wide range of regulatory cellular processes. Notch, an ankyrin domain containing protein, signals by converting a transcriptional repression complex into an activation complex. The Notch ANK domain is essential for Notch function and contains seven ARs. Here, we present the 2.2 Å crystal structure of ARs 4–7 from mouse Notch 1 (m1ANK). These C‐terminal repeats were resistant to degradation during crystallization, and their secondary and tertiary structures are maintained in the absence of repeats 1–3. The crystallized fragment adopts a typical ankyrin fold including the poorly conserved seventh AR, as seen in the Drosophila Notch ANK domain (dANK). The structural preservation and stability of the C‐terminal repeats shed a new light onto the mechanism of hetero‐oligomeric assembly during Notch‐mediated transcriptional activation.
One‐ and two‐body decomposable Poisson‐Boltzmann methods for protein design calculations
Authors: Marshall Shannon A. , Vizcarra Christina L. , Mayo Stephen L. 
Published: April 2005

AbstractSuccessfully modeling electrostatic interactions is one of the key factors required for the computational design of proteins with desired physical, chemical, and biological properties. In this paper, we present formulations of the finite difference Poisson‐Boltzmann (FDPB) model that are pairwise decomposable by side chain. These methods use reduced representations of the protein structure based on the backbone and one or two side chains in order to approximate the dielectric environment in and around the protein. For the desolvation of polar side chains, the two‐body model has a 0.64 kcal/mol RMSD compared to FDPB calculations performed using the full representation of the protein structure. Screened Coulombic interaction energies between side chains are approximated with an RMSD of 0.13 kcal/mol. The methods presented here are compatible with the computational demands of protein design calculations and produce energies that are very similar to the results of traditional FDPB calculations.
Visualization of conformational distribution of short to medium size segments in globular proteins and identification of local structural motifs
Authors: Ikeda Kazuyoshi , Tomii Kentaro , Yokomizo Tsuyoshi , Mitomo Daisuke , Maruyama Keiichiro , Suzuki Shinya , Higo Junichi 
Published: April 2005

AbstractAnalysis of the conformational distribution of polypeptide segments in a conformational space is the first step for understanding a principle of structural diversity of proteins. Here, we present a statistical analysis of protein local structures based on interatomic Cα distances. Using principal component analysis (PCA) on the intrasegment Cα–Cα atomic distances, the conformational space of protein segments, which we call the protein segment universe, has been visualized, and three essential coordinate axes, suitable for describing the universe, have been identified. Three essential axes specified radius of gyration, structural symmetry, and separation of hairpin structures from other structures. Among the segments of arbitrary length, 6–22 residues long, the conservation of those axes was uncovered. Further application of PCA to the two largest clusters in the universe revealed local structural motifs. Although some of motifs have already been reported, we identified a possibly novel strand motif. We also showed that a capping box, which is one of the helix capping motifs, was separated into independent subclusters based on the Cα geometry. Implications of the strand motif, which may play a role for protein–protein interaction, are discussed. The currently proposed method is useful for not only mapping the immense universe of protein structures but also identification of structural motifs.
Crystal structure of yeast YHR049W/FSH1, a member of the serine hydrolase family
Authors: Quevillon‐Cheruel Sophie , Leulliot Nicolas , Graille Marc , Hervouet Nadège , Coste Frank , Bénédetti Hélène , Zelwer Charles , Janin Joel , Van Tilbeurgh Herman 
Published: April 2005

AbstractYhr049w/FSH1 was recently identified in a combined computational and experimental proteomics analysis for the detection of active serine hydrolases in yeast. This analysis suggested that FSH1 might be a serine‐type hydrolase belonging to the broad functional αβ‐hydrolase superfamily. In order to get insight into the molecular function of this gene, it was targeted in our yeast structural genomics project. The crystal structure of the protein confirms that it contains a Ser/His/Asp catalytic triad that is part of a minimal α/β‐hydrolase fold. The architecture of the putative active site and analogies with other protein structures suggest that FSH1 may be an esterase. This finding was further strengthened by the unexpected presence of a compound covalently bound to the catalytic serine in the active site. Apparently, the enzyme was trapped with a reactive compound during the purification process.
Isolation and characterization of strains of Flavobacterium columnare from Brazil
Authors: Figueiredo H C P , Klesius P H , Arias C R , Evans J , Shoemaker C A , Pereira D J , Peixoto M T D 
Published: April 2005

Abstract Flavobacterium columnare is an important pathogen of freshwater fish, implicated in skin and gill disease, often causing high mortality. An outbreak of skin disease in fingerling and adult Nile tilapia, Oreochromis niloticus (L.), cultivated in a recirculation system, was investigated. Four strains were isolated and characterized by biochemical reactions, enzyme production, fatty acid profile and analysis of the 16S‐23S rDNA intergenic spacer region. All strains were identified as F. columnare. Experimental infection assays with one of these strains (BZ‐5‐02) were conducted and pathogenicity (by intramuscular route) was demonstrated in Nile tilapia and channel catfish, Ictalurus punctatus (Rafinesque). This is the first report of characterization of Brazilian strains of F. columnare.