bluuebunny/crossref_metadata_2025_split huggingface dataset:
Can size alone explain some of the differences in toxicity between β‐amyloid oligomers and fibrils?
Authors: Keshet Ben , Yang In Hong , Good Theresa A. 
Published: February 2010

Abstractβ‐Amyloid (Aβ) peptide is believed to play a key role in the mechanism of Alzheimer's disease (AD). Aβ tends to aggregate to form amyloid fibrils. A variety of evidence indicates that Aβ aggregates are toxic in vitro and in vivo. An early “Aβ hypothesis” postulated that AD was the consequence of neuron death induced by insoluble deposits of large Aβ fibrils. Newer findings indicate that small soluble Aβ oligomers are the neurotoxic species, yet their structure is still unknown. Many researchers have tried to probe the differences in molecular structure between Aβ oligomers, protofibrils, and fibrils that give rise to their unique toxicities, but with limited success. In this report, we examine the hypothesis that differences in the toxicity of different aggregated Aβ species are the result of differences in species concentration and diffusivity. Using a simple mathematical analysis based on the assumption of a diffusion‐limited reaction, we demonstrate that near 10‐fold differences in toxicity between spherical oligomers and fibrils can be explained from size and concentration arguments. While this work does not suggest that Aβ oligomers and fibrils have identical molecular structures, it highlights the possibility that simple physical phenomena may contribute to the biological processes induced by Aβ. Biotechnol. Bioeng. 2010;106: 333–337. © 2010 Wiley Periodicals, Inc.
Intraparticle concentration gradients for substrate and acidic product in immobilized cephalosporin C amidase and their dependencies on carrier characteristics and reaction parameters
Authors: Boniello Caterina , Mayr Torsten , Klimant Ingo , Koenig Burghard , Riethorst Waander , Nidetzky Bernd 
Published: February 2010

AbstractCephalosporin C amidase was covalently attached using a protein loading of 7.0–200 mg protein/g dry carrier on four epoxy‐activated Sepabeads differing in particle size and pore diameter. Initial‐rate kinetic analysis showed that for Sepabeads with small pore diameters (30–40 nm), the apparent KM of the amidase for hydrolysis of cephalosporin C at 37°C and pH 8.0 increased ∼3‐fold in response to increased particle size (∼120–400 µm) and increased amount of immobilized enzyme (7.0–70 mg protein/g dry carrier) while maximum specific activity (3.2 U/mg protein; 25% of free amidase) was affected only by particle size. In contrast, for Sepabeads with wide pores (150–250 nm), the KM was independent of the enzyme loading. Internal effectiveness factors calculated from observable Thiele modulus reflected the dependence of KM on geometrical parameters of the particles. A new method for determination of the overall intraparticle pH was developed based on luminescence lifetime measurements in the frequency domain. Sepabeads were doubly labeled using a lipophilic variant of the pH‐sensitive dye fluorescein, and Ru(II) tris(4,7‐diphenyl‐1,10‐phenantroline) whose phosphorescence properties are independent of pH. Luminescent lifetime measurements of doubly labeled particle suspensions showed superior signal‐to‐noise ratio compared to fluorescence intensity‐based measurements using singly labeled particles. The difference at apparent steady state (ΔpH) between bulk (external pH) and intraparticle pH (internal pH) was as large as ∼0.6 units. The ΔpH was dependent on substrate concentration, particle size, and pore diameter. Therefore, these results characterize the role of carrier characteristics and reaction parameters in the formation of concentration gradients for substrate and acidic product during hydrolysis of cephalosporin C by immobilized amidase. The strong pH dependence of the immobilized amidase underscores the importance of considering intraparticle pH gradients in the design of an efficient carrier‐bound biocatalyst. Biotechnol. Bioeng. 2010;106: 528–540. © 2010 Wiley Periodicals, Inc.
Broad‐host‐range vectors for protein expression across gram negative hosts
Authors: Prior Jamie E. , Lynch Michael D. , Gill Ryan T. 
Published: February 2010

AbstractExpression of recombinant proteins across a range of different host organisms is often necessary in metabolic engineering applications. Doing so can be facilitated by the use of vectors having origins of replication with a broad‐host‐range, the option for antibiotic resistance cassettes that are compatible with a particular host, in addition to sequences allowing for the effective transcription and translation of target proteins. We have created a modular set of broad‐host‐range expression vectors for protein expression in Gram negative bacteria. These vectors use the broad‐host‐range pBBR1 replicon as well as the arabinose‐inducible PBAD promoter and are available with six different antibiotic resistance cassettes. We have demonstrated the use of these vectors in Escherichia coli, Pseudomonas putida, and Burkholderia cepacia. Biotechnol. Bioeng. 2010;106: 326–332. © 2010 Wiley Periodicals, Inc.
β‐Cyclodextrin hydrogels containing naphthaleneacetic acid for pH‐sensitive release
Authors: Yang Xia , Kim Jin‐Chul 
Published: February 2010

Abstractβ‐Cyclodextrin (β‐CD) hydrogel was prepared in a strong alkali condition using epichlorohydrin (EPI) as a cross‐linker, where the molar ratios of EPI to β‐CD were 8:1, 10:1, and 15:1. In order to endow a pH sensitivity to the hydrogel, naphthaleneacetic acid (NAA) was loaded in the hydrogel by taking advantage of its hydrophobic interaction with the cavities of β‐CD. The releases of blue dextran (a water‐soluble dye) from the hydrogels were promoted, as the pHs of the media increased. When the molar ratio of EPI to β‐CD was lower, the degrees of release were higher, and the pH dependency of the release became more prominent. In fact, the swelling ratio of the hydrogels having a lower molar ratio of EPI to β‐CD was higher. The higher swelling ratio would account for the higher degree of release and the marked pH sensitivity. Biotechnol. Bioeng. 2010;106: 295–302. © 2010 Wiley Periodicals, Inc.
Modulation of alignment and differentiation of skeletal myoblasts by submicron ridges/grooves surface structure
Authors: Wang Peng‐Yuan , Yu Hung‐Te , Tsai Wei‐Bor 
Published: February 2010

AbstractAlignment and fusion of myoblasts into parallel arrays of multinucleated myotubes are critical in skeletal muscle tissue engineering. It is well known that contact guidance by grooves/ridges structures induces myoblasts to align and to migrate along the anisotropic direction. In this study, two series of grooved substrata with different widths (450 and 900 nm) and different depths (100, 350, and 550 nm) were studied on their effects on myoblast adhesion, proliferation, and differentiation into myotubes. We found that C2C12 cells were aligned and elongated along the direction of grooves. Groove depth was more influential on cellular morphology, proliferation, and differentiation than groove width. While cell proliferation was retarded on the grooved surfaces especially on the substrate with 900/550 nm (width/depth), differentiation was also enhanced on the patterned surfaces compared to the flat control. Our results demonstrated the potential of grooved substrata with submicron scale in skeletal muscle tissue engineering. Biotechnol. Bioeng. 2010;106: 285–294. © 2010 Wiley Periodicals, Inc.
Click‐Chemistry‐Derived Tetracycline–Amino Acid Conjugates Exhibiting Exceptional Potency and Exclusive Recognition of the Reverse Tet Repressor
Authors: Usai Igor , Krueger Marcus , Einsiedel Jürgen , Hillen Wolfgang , Gmeiner Peter 
Published: February 2010

AbstractA click‐chemistry‐based synthesis of biologically active doxycycline–amino acid conjugates is described. Starting from 9‐aminodoxycycline derivatives and complementary functionalized amino acids, ligation was accomplished by copper(I)‐catalyzed azide–alkyne [3+2] cycloaddition (CuAAC). The final products were tested in a variety of TetR and revTetR systems, and the C‐terminally linked phenylalanine conjugate 12 c exhibited high selectivity for revTetR over TetR. Besides the unique property of the specific effector 12 c to effectively differentiate TetR and its reverse phenotype, the test compound proved to be almost devoid of any antibacterial activity; this will be highly beneficial for future applications to control gene expression in bacterial systems.
An Alternative Technology to Form Tablets
Authors: Witte A. , Ulrich J. 
Published: February 2010

AbstractThe idea of a freeze casting process is introduced in order to convert heat and/or pressure sensitive pharmaceutical ingredients into a tablet form. The process line involves the freezing of a water‐based suspension including a pharmaceutically active ingredient and a drying step (sublimation). The results of these procedures are highly porous solid tablet bodies. The tensile strength and dissolution behavior of the bodies are examined. It is shown that the hardness of the tablets depends on the composition of the suspension, which is not quite satisfactorily reached. The porosity, and therefore, the dissolution behavior depend on the process parameters and correlate with the tensile strength. Much better dissolution rates can be obtained with the new tablets than with commercial products. The proof of concept for tablet manufacturing by the route of freeze casting is successfully demonstrated.
Influence of Heart Rate on Quality of Life in Patients With Chronic Atrial Fibrillation
Authors: Jaber Jefferson , Cirenza Claudio , Jaber Jeffrey , Amaral Alessandro , Almeida de Sousa José Marconi , Oliveira Filho Japy A. , de Paola Angelo A. V. 
Published: February 2010

AbstractBackgroundCurrent criteria for rate control in atrial fibrillation (AF) treatment are empirical and based on a small amount of scientific data.HypothesisThis study was designed to analyze the influence of heart rate (HR, measured by the 6‐minute walk test [6MWT] and 24‐hour Holter monitoring) on quality of life (QoL).MethodsA total of 89 male patients with chronic atrial fibrillation (AF) and resting HR < 90 bpm were included. QoL (assessed by the Short Form‐36 Health Survey [SF‐36] questionnaire) was compared among 3 groups of patients classified by HR testing results: group 1 had HR ≤ 110 bpm on 6MWT and ≤ 80 bpm on Holter monitor; group 2 had HR in the target area by 1 but not both tests; and group 3 had HR > 110 bpm on 6MWT and > 80 bpm on Holter monitor.ResultsThere were significant differences among the 3 groups in physical and mental component summary scores (285.9 ± 73.9; 276.6 ± 80.8; 230.3 ± 91.0, P = .035; and 319.8 ± 70.2; 294.7 ± 76.0; 255.0 ± 107.1, P = .026, respectively).When the methods were analyzed separately, there was a significant difference on QoL in physical and mental summary scores in patients with maximal HR ≤ 110 bpm on 6MWT in comparison with HR > 110 bpm (P = .04 and P = .01, respectively) and in the physical summary score in patients with average HR ≤ 80 bpm on Holter monitor in comparison with HR > 80 bpm (P = .02).ConclusionsHolter monitoring and 6MWT should be performed as complementary methods to better predict QoL. Copyright © 2010 Wiley Periodicals, Inc.
Cause of death in patients with lower‐risk myelodysplastic syndrome
Authors: Dayyani Farshid , Conley Anthony P. , Strom Sara S. , Stevenson William , Cortes Jorge E. , Borthakur Gautam , Faderl Stefan , O'Brien Susan , Pierce Sherry , Kantarjian Hagop , Garcia‐Manero Guillermo 
Published: February 2010

AbstractBACKGROUND:The authors have recently shown that a majority of patients with myelodysplastic syndrome (MDS) classified by the International Prognostic Scoring System as lower risk die without transformation to acute myelogenous leukemia (AML). The cause of death (COD) of these patients is not well understood. Identifying the COD could help to guide early therapy decisions.METHODS:The authors retrospectively analyzed the COD in a cohort of 273 deceased patients with lower‐risk MDS according to the International Prognostic Scoring System at presentation to The University of Texas M. D. Anderson Cancer Center from 1980 to 2004. MDS‐related death was defined as infection, bleeding, transformation to AML, or disease progression. Remaining CODs were classified as non–MDS‐related.RESULTS:Median age at presentation was 66 years (range, 19‐88 years). Overall median survival was 59 weeks (range, 1‐831 weeks). All French‐American‐British leukemia classification subgroups were represented. The percentage of International Prognostic Scoring System low and intermediate‐1 groups were 21% and 79%, respectively. The most common cytogenetic abnormality (9%) was del(5q). Patients received supportive care only. The COD was identified as MDS‐related in 230 of 273 (84%) patients. The most common disease‐related CODs were infection (38%), transformation to AML (15%), and hemorrhage (13%). The most frequent non–disease‐related COD was cardiovascular events (19 of 43 patients).CONCLUSIONS:The majority of patients with low‐ or intermediate‐1 risk MDS will die because of causes related to their underlying disease. Although these results need to be validated in different populations, early therapeutic intervention could be considered in the management of these patients to improve survival. Cancer 2010. © 2010 American Cancer Society.
Angiosarcoma after breast‐conserving therapy
Authors: Palta Manisha , Morris Christopher G. , Grobmyer Stephen R. , Copeland Edward M. , Mendenhall Nancy P. 
Published: February 2010

AbstractBACKGROUND:With breast‐conserving therapy (BCT) as the standard of care for patients with noninvasive and early stage invasive breast cancer, a small incidence of post‒BCT angiosarcoma has emerged. The majority of therapeutic interventions have been unsuccessful. To the authors' knowledge, there is no consensus in the medical literature to date regarding the treatment of this malignancy. The current study was conducted to report the long‐term outcomes of a novel approach using hyperfractionated and accelerated radiotherapy (HART) for angiosarcoma developing after BCT.METHODS:The authors retrospectively reviewed the outcomes of 14 patients treated with HART with or without surgery at the University of Florida between November 1997 and March 2006 for angiosarcoma that developed after BCT.RESULTS:At the time of last follow‒up, 9 patients had remained continuously without evidence of disease for a median of 61 months after HART (range, 36‐127 months). Five patients had further manifestations of angiosarcoma after HART at a median of 1 month (range, 1‒28 months): 3 with progressive pulmonary and/or mediastinal disease that was likely present before HART and 2 with local or regional disease extension. Progression‐free survival rates for the 14 patients at 2 years and 5 years were 71% and 64%, respectively. The overall and cause‐specific survival rates were both 86% at 2 years and 5 years.CONCLUSIONS:To the best of the authors' knowledge, HART with or without subsequent surgery, as documented in the current series, is the first approach to provide a high rate of local control, disease‐free survival, and overall survival after the development of post‒BCT angiosarcoma. The authors believe the success noted with this approach is related to both the hyperfractionation and acceleration of the RT. Cancer 2010. © 2010 American Cancer Society.
Light responses and morphology of bNOS‐immunoreactive neurons in the mouse retina
Authors: Pang Ji‐Jie , Gao Fan , Wu Samuel M. 
Published: February 2010

AbstractNitric oxide (NO), produced by NO synthase (NOS), modulates the function of all retinal neurons and ocular blood vessels and participates in the pathogenesis of ocular diseases. To further understand the regulation of ocular NO release, we systematically studied the morphology, topography, and light responses of NOS‐containing amacrine cells (NOACs) in dark‐adapted mouse retina. Immunohistological staining for neuronal NOS (bNOS), combined with retrograde labeling of ganglion cells (GCs) with Neurobiotin (NB, a gap junction permeable dye) and Lucifer yellow (LY, a less permeable dye), was used to identify NOACs. The light responses of ACs were recorded under whole‐cell voltage clamp conditions and cell morphology was examined with a confocal microscope. We found that in dark‐adapted conditions bNOS‐immunoreactivity (IR) was present primarily in the inner nuclear layer and the ganglion cell layer. bNOS‐IR somas were negative for LY, thus they were identified as ACs; nearly 6% of the cells were labeled by NB but not by LY, indicating that they were dye‐coupled with GCs. Three morphological subtypes of NOACs (NI, NII, and displaced) were identified. The cell density, intercellular distance, and the distribution of NOACs were studied in whole retinas. Light evoked depolarizing highly sensitive ON‐OFF responses in NI cells and less sensitive OFF responses in NII cells. Frequent (1–2 Hz) or abrupt change of light intensity evoked larger peak responses. The possibility for light to modify NO release from NOACs is discussed. J. Comp. Neurol. 518:2456–2474, 2010. © 2010 Wiley‐Liss, Inc.
Somatosensory nucleus in the torus semicircularis of cyprinid teleosts
Authors: Yamamoto Naoyuki , Kato Takeshi , Okada Yuji , Somiya Hiroaki 
Published: February 2010

AbstractCytoarchitecture and fiber connections of the ventrolateral region of torus semicircularis were studied in goldfish and carp. Cytoarchitectural analyses indicate that two toral nuclei, ventrolateral (TSvl) and external (TSe) nuclei, are present in this toral region. The TSvl mainly receives lateral line inputs from the medial nucleus of the rhombencephalic octavolateral area, while the TSe mainly receives somatosensory fibers from the spinal cord, sensory trigeminal nuclei, and lateral funicular nucleus. The TSe also receives sparse fibers from the retina and the octavolateral area medial nucleus and sends descending fibers to the lateral funicular nucleus. Both toral nuclei receive projections from the ventromedial thalamic nucleus and the central part of dorsal telencephalic area, although the latter descending fibers terminate mainly in the TSvl. Both toral nuclei project to the rostrolateral region of lateral preglomerular nucleus, restricted to the somata layer of the dorsal zone of the region. Ventrolateral and external toral fibers, however, tended to reach lateral and medial zones of the somata layer, respectively. The present study suggests that there are three functional compartments within the cyprinid torus semicircularis (central nucleus: auditory, TSvl: lateral line, and TSe: somatosensory) and that sensory pathways arising from these toral compartments maintain largely separate ascending systems into the forebrain. The present study also extends knowledge of the organization and connections of the lateral valvular nucleus and nucleus praeeminentialis that project to the cerebellar granular layer and cerebellar crest, respectively. J. Comp. Neurol. 518:2475–2502, 2010. © 2010 Wiley‐Liss, Inc.
Projections of the hand field of the macaque ventral premotor area F5 to the brainstem and spinal cord
Authors: Borra Elena , Belmalih Abdelouahed , Gerbella Marzio , Rozzi Stefano , Luppino Giuseppe 
Published: February 2010

AbstractIn the present study we first assessed that the hand motor field of the macaque ventral premotor area F5, involved in visuomotor control of hand actions, is connected to both the hand field of the primary motor cortex (M1) and the spinal cord. We then injected retroanterograde tracers in this field to completely illustrate its possible descending motor projections. In the brainstem the F5 hand motor field projects to the intermediate and deep layers of the superior colliculus (SC) and to sectors of the mesencephalic, pontine, and bulbar reticular formation, which are the sources of spinal projections. In the spinal cord, labeled terminals were virtually all confined to the C2–T1 segments, mostly contralaterally. At C6–T1 levels the labeling was weaker and mostly clustered laterally in the intermediate zone. At C2–C5 levels, labeled terminals were much denser and diffusely distributed over the mid‐dorsal part of the intermediate zone where a propriospinal system that directly controls hand muscle motoneurons and mediates commands for the control of dexterous finger movements is located (Isa et al. [2007] Physiology 22:145–152). Thus, the F5 hand motor field has a weaker direct access and a stronger indirect access to spinal segments where hand muscle motoneurons are located, suggesting a role of this field in the generation and control of hand movements not only at the M1 level, but also at the spinal cord level. These projections may represent the neural substrate for the F5 hand motor field's role in the recovery of manual dexterity after M1 lesions. J. Comp. Neurol. 518:2570–2591, 2010. © 2010 Wiley‐Liss, Inc.
Securing cognitive radio networks
Authors: León O. , Hernández‐Serrano J. , Soriano M. 
Published: February 2010

AbstractCognitive radio is a promising technology aiming to improve the utilization of the radio electromagnetic spectrum. A cognitive radio device uses general purpose computer processors that run radio applications software to perform signal processing. The use of this software enables the device to sense and understand its environment and actively change its mode of operation based on its observations. Unfortunately, this solution entails new security challenges. Our objective in this paper is to analyze the security issues of the main recent developments and architectures of cognitive radio networks. We present vulnerabilities inherent to those systems, identify novel types of abuse, classify attacks, and analyze their impact on the operation of cognitive radio‐based systems. Moreover, we discuss and propose security solutions to mitigate such threats. Copyright © 2010 John Wiley & Sons, Ltd.
Three inhibitors of FGF receptor, ERK, and GSK3 establishes germline‐competent embryonic stem cells of C57BL/6N mouse strain with high efficiency and stability
Authors: Kiyonari Hiroshi , Kaneko Mari , Abe Shin‐ichi , Aizawa Shinichi 
Published: February 2010

AbstractC57BL/6 mouse is the most standard strain in mouse genetics. The strain does, however, have several disadvantages; one being the difficulty in establishing embryonic stem (ES) cells. No reliable C57BL/6 ES cell line is widely available for creating mutant mice through gene targeting. It also greatly favors mouse genetics if one can routinely make multiple mutations by stably culturing germline‐competent C57BL/6 ES cells or if one can routinely establish ES cells from C57BL/6‐derived mutant mice to make multiple mutations. Recently, an ES culture method with three inhibitors (3i: SU5402 for FGFR, PD184352 for ERK, and CHIR99021 for GSK3) has been reported. Here we show that this 3i method is extremely instrumental in establishing and culturing germline‐competent ES cells in the C57BL/6N strain. genesis 48:317–327, 2010. © 2010 Wiley‐Liss, Inc.