bluuebunny/crossref_metadata_2025_split huggingface dataset:
3D culture of osteoblast‐like cells by unidirectional or oscillatory flow for bone tissue engineering
Authors: Du Dajiang , Furukawa Katsuko S. , Ushida Takashi 
Published: December 2008

AbstractA medium perfusion system is expected to be beneficial for three‐dimensional (3D) culture of engineered bone, not only by chemotransport enhancement but also by mechanical stimulation. In this study, perfusion systems with either unidirectional or oscillatory medium flow were developed, and the effects of the different flow profiles on 3D culturing of engineered bone were studied. Mouse osteoblast‐like MC 3T3‐E1 cells were 3D‐cultured with porous ceramic scaffolds in vitro for 6 days under static and hydrodynamic conditions with either a unidirectional or oscillatory flow. We found that, in the static culture, the cells proliferated only on the scaffold surfaces. In perfusion culture with the unidirectional flow, the proliferation was significantly higher than in the other groups but was very inhomogeneous, which made the construct unsuitable for transplantation. Only the oscillatory flow allowed osteogenic cells to proliferate uniformly throughout the scaffolds, and also increased the activity of alkaline phosphatase (ALP). These results suggested that oscillatory flow might be better than unidirectional flow for 3D construction of cell‐seeded artificial bone. The oscillatory perfusion system could be a compact, safe, and efficient bioreactor for bone tissue engineering. Biotechnol. Bioeng. 2009;102: 1670–1678. © 2008 Wiley Periodicals, Inc.
Modification of native collagen with cell‐adhesive peptide to promote RPE cell attachment on Bruch's membrane
Authors: Sistiabudi Rizaldi , Paderi John , Panitch Alyssa , Ivanisevic Albena 
Published: December 2008

AbstractCurrent efforts to reverse loss of visual function due to Age‐related Macular Degeneration point to the restoration of the Retinal Pigment Epithelial (RPE) layer. Restoration of the RPE layer involves replacing lost RPE cells as well as addressing the degeneration of the underlying Bruch's membrane (BM). To advance the potential of using donor BM, we present a strategy to achieve specific and controllable modification of the inner collagenous layer (ICL) of the Bruch's membrane. In particular, interaction between a collagen binding peptide (CBP) sequence with exposed collagen fibers on the ICL surface is utilized to anchor bioactive molecules. Here, a cell‐adhesion sequence is added to the collagen binding sequence to promote attachment and survival of ARPE‐19. First, the binding specificity of the CBP sequence is verified with a fluorescent binding assay. Subsequently, the effect of modification using the peptide is studied qualitatively using confocal fluorescent imaging and quantitatively through a cell proliferation assay. Results of these experiments indicate that the peptide sequence binds specifically to collagen fibers. Additionally, modification using the peptide enhanced cell adhesion, allowing large uniform cell networks to be formed on the surface. Furthermore, modification with the peptide also delayed the onset of apoptosis on adherent cells. Biotechnol. Bioeng. 2009;102: 1723–1729. © 2008 Wiley Periodicals, Inc.
Development of mammalian production cell lines expressing CNTO736, a glucagon like peptide‐1‐MIMETIBODYTM: Factors that influence productivity and product quality
Authors: Dorai Haimanti , Nemeth Jennifer F. , Cammaart Erwin , Wang Yonghui , Tang Qing Mike , Magill Allen , Lewis Michael J. , Raju T. Shantha , Picha Kristen , O'Neil Karyn , Ganguly Subinay , Moore Gordon 
Published: December 2008

AbstractIn an attempt to develop a high producing mammalian cell line expressing CNTO736, a Glucagon like peptide‐1‐antibody fusion protein (also known as a Glucagon like peptide‐1 MIMETIBODYTM), we have noted that the N‐terminal GLP‐1 portion of the MIMETIBODYTM was susceptible to proteolytic degradation during cell culture, which resulted in an inactive product. Therefore, a number of parameters that had an effect on productivity as well as product quality were examined. Results suggest that the choice of the host cell line had a significant effect on the overall product quality. Product expressed in mouse myeloma host cell lines had a lesser degree of proteolytic degradation and variability in O‐linked glycosylation as compared to that expressed in CHO host cell lines. The choice of a specific CHOK1SV derived clone also had an effect on the product quality. In general, molecules that exhibited minimal N‐terminal clipping had increased level of O‐linked glycosylation in the linker region, giving credence to the hypothesis that O‐linked glycosylation acts to protect against proteolytic degradation. Moreover, products with reduced potential for N‐terminal clipping had longer in vivo serum half‐life. These findings suggest that early monitoring of product quality should be an essential part of production cell line development and therefore, has been incorporated in our process of cell line development for this class of molecules. Biotechnol. Bioeng. 2009;103: 162–176. © 2008 Wiley Periodicals, Inc.
The state and evolution of information systems research in canada: a scientometric analysis
Authors: Serenko Alexander , Cocosila Mihail , Turel Ofir 
Published: December 2008

AbstractThis paper investigates the state and evolution of information systems (IS) research in Canada as reflected in publications of the proceedings of the annual conference of the Administrative Sciences Association of Canada from 1974 to 2007. We present a scientometric analysis of (a) individual and institutional research outputs; (b) differences in three productivity score calculation methods: straight count, equal credit, and author position; (c) study topics; (d) research methods; and (e) use of student samples. Copyright © 2008 ASAC. Published by John Wiley & Sons, Ltd.
Promoter methylation of the Wnt/β‐catenin signaling antagonist Dkk‐3 is associated with poor survival in gastric cancer
Authors: Yu Jun , Tao Qian , Cheng Yuen Y. , Lee Kwan Y. , Ng Simon S. M. , Cheung Kin F. , Tian Linwei , Rha Sun Y. , Neumann Ulf , Röcken Christoph , Ebert Matthias P. A. , Chan Francis K. L. , Sung Joseph J. Y. 
Published: December 2008

AbstractBACKGROUND:Abnormal activation of the Wnt/β‐catenin signaling pathway is common and critical in the pathogenesis of digestive cancers. In this study, the authors investigated the promoter methylation of the dickkopf homolog 3 gene Dkk‐3 in these cancers and its prognostic significance in gastric cancer.METHODS:Dkk‐3 methylation was assessed in 173 patients with gastric cancers (including 104 patients who were followed for up to 4090 days) and in 128 patients with colorectal cancer. Cell growth was evaluated by using a colony‐formation assay. For survival analyses, the authors used Kaplan‐Meier plots, the log‐rank test, and Cox proportional regression.RESULTS:Dkk‐3 was silenced or down‐regulated in 12 of 17 gastric cancer cell lines (70.6%) and in 3 of 9 colon cancer cell lines (33.3%). The loss of gene expression was associated with promoter methylation, which could be restored by demethylating agents. Ectopic expression of Dkk‐3 suppressed colony formation. Moreover, methylation of Dkk‐3 was detected in 117 of 173 primary gastric tumors (67.6%) and in 67 of 128 colorectal tumors (52.3%). The clinical significance and the prognostic value of Dkk‐3 methylation also were examined in 104 gastric cancers and in 84 colorectal cancers. Multivariate analysis indicated that Dkk‐3 methylation was associated significantly and independently with poor disease survival (relative risk, 2.534; 95% confidence interval, 1.54–4.17; P = .002) in gastric cancer, but not in colorectal cancer. Kaplan‐Meier survival curves revealed that patients who had Dkk‐3 methylated gastric cancers had a significantly shorter survival (median, 0.76 years) compared with patients who did not have Dkk‐3 methylation (median, 2.68 years; P < .0001; log‐rank test).CONCLUSIONS:Epigenetic silencing of the Dkk‐3 gene by promoter methylation was a common event in gastric cancer and was associated with a poor outcome in such patients. Cancer 2009. © 2008 American Cancer Society.
Murine bone marrow–derived mesenchymal stem cells as vehicles for interleukin‐12 gene delivery into Ewing sarcoma tumors
Authors: Duan Xiaoping , Guan Hui , Cao Ying , Kleinerman Eugenie S. 
Published: December 2008

AbstractBACKGROUND:This study evaluated the therapeutic efficacy of interleukin 12 (IL‐12) gene therapy in Ewing sarcoma and whether murine mesenchymal stem cells (MSCs) could serve as vehicles for IL‐12 gene delivery.METHODS:MSCs were isolated from murine bone marrow cells. Cells were phenotyped using flow cytometry. Cultured MSCs differentiated into osteocytes and adipocytes using the appropriate media. Freshly isolated MSCs were transfected with adenoviral vectors containing either the β‐galactosidase (Ad:β‐gal) or the IL‐12 (Ad:IL‐12) gene. Expression of IL‐12 was confirmed using reverse transcription polymerase chain reaction. Mice with TC71 Ewing sarcoma tumors were then treated intravenously with MSCs transfected with Ad:β‐gal or Ad:IL‐12. Tumors were measured and analyzed by immunohistochemical analysis for expression of IL‐12 protein.RESULTS:Expression of both p35 and p40 IL‐12 subunits was demonstrated in MSCs transfected in vitro with Ad:IL‐12. IL‐12 expression was seen in tumors from mice treated with MSCs transfected with Ad:IL‐12. Tumor growth was also significantly inhibited compared with that in mice treated with MSCs transfected with Ad:β‐gal.CONCLUSIONS:MSCs can be transfected with the IL‐12 gene. These transfected cells localize to tumors after intravenous injection and induce local IL‐12 protein production and the regression of established tumors. Cancer 2009. © 2008 American Cancer Society.
Analysis of early ventral telencephalic defects in mice lacking functional Gli3 protein
Authors: Yu Tian , Fotaki Vassiliki , Mason John O. , Price David J. 
Published: December 2008

AbstractThe transcription factor Gli3 is expressed throughout developing telencephalon. Previous studies have focused on Gli3's role in dorsal telencephalon, which is greatly reduced in size inGli3Xt/Xtmutants. We examined the effects of loss of Gli3 on early development of ventral telencephalon. Ventral telencephalon was defined in both wildtypes andGli3Xt/Xtmutants on the basis of its expression of Olig2, Nkx2.1, Mash1, and Foxg1 and its lack of expression of Pax6. We found that at embryonic day (E)10.5 the volume of the ventral telencephalon is about 50% greater inGli3Xt/Xtmutants than in wildtypes. By E12.5, however, the volume of the ventral telencephalon is about 20% lower inGli3Xt/Xtmutants than in wildtypes. We observed a significant increase in the number of both apoptotic cells and newly differentiated neurons in the E10.5Gli3Xt/Xtventral telencephalon, suggesting that increased cell death and withdrawal of cells from the cell cycle might account for the failure of theGli3Xt/Xtventral telencephalon to grow normally by E12.5. We found no changes in the lengths of the cell cycles of proliferating ventral telencephalic cells at E10.5. We used marker analysis and optical projection tomography to assess theGli3Xt/Xtforebrain in three dimensions and found that theGli3Xt/Xtdiencephalon is shifted relatively rostrally. We conclude that in the absence of Gli3 an abnormally large portion of the newly formed telencephalon is specified to a ventral fate but this then suffers impaired growth, due to defects of cell differentiation and death, contributing to severe distortion of the forebrain. J. Comp. Neurol. 512:613–627, 2009. © 2008 Wiley‐Liss, Inc.
Central projections of octavolateralis nerves in the brain of a soniferous damselfish (Abudefduf abdominalis)
Authors: Maruska Karen P. , Tricas Timothy C. 
Published: December 2008

AbstractSounds and hydrodynamic stimuli are important cues detected by the octavolateralis system in fishes. The central organization of auditory, mechanosensory, and vestibular projections is known for only a few phylogenetically diverse fishes, and less is known about projections in derived perciforms that use sounds for acoustic communication. We used neuronal labeling to provide a detailed analysis of octavolateralis endorgan projections in a soniferous perciform that does not have accessory morphological structures to enhance hearing. Octavolateralis nerves terminate ipsilaterally within seven medullary octaval nuclei: caudal (CON) and medial (MON) octavolateralis, anterior (AON), descending (DON), magnocellular (MgON), tangential (TON), and posterior (PON) octaval nuclei, and the eminentia granularis (EG). Anterior and posterior lateral line nerves project to the CON and MON, with dense projections to the EG. Semicircular canal nerves project primarily to ventral regions including the TON, ventral DON, intermediate DON (DONi), and MgON. Otolithic, semicircular canal, and anterior lateral line nerves all project to the MgON, which may serve a sensorimotor integration function. The DONi receives primarily segregated projections from all otolithic and semicircular canal nerves, whereas the ventral DON and TON receive principally utricular and semicircular canal afferents. The AON receives dense lateral and ventral projections from the saccule and utricle, and medial and dorsal projections from the lagena. These projection patterns are similar to those reported for non‐sonic perciforms, and indicate the absence of neuroanatomical modifications in first‐order octavolateralis nuclei in species that use acoustic communication. Thus patterns of central projections may be conserved among vocal and non‐vocal perciforms. J. Comp. Neurol. 512:628–650, 2009. © 2008 Wiley‐Liss, Inc.
Application of the homotopy perturbation method for the Fokker–Planck equation
Authors: Yıldırım Ahmet 
Published: December 2008

AbstractIn this paper, we will discuss the solution of an initial value problem of parabolic type. The main objective is to propose an alternative method of solution, one not based on finite difference or finite element or spectral methods. The aim of the present paper is to investigate the application of the Homotopy perturbation method (HPM) for solving the Fokker–Planck equation and some similar equations. This method is a powerful tool for solving various kinds of problems. Employing this technique, it is possible to find the exact solution or an approximate solution of the problem. The results show applicability, accuracy and efficiency of HPM in solving nonlinear differential equations. It is predicted that HPM can be widely applied in science and engineering problems. Copyright © 2008 John Wiley & Sons, Ltd.
A new numerical method for BLT forward problem based on high‐order finite elements
Authors: Hou Yanbin , Tian Jie , Wu Yan , Liang Jimin , He Xiaowei 
Published: December 2008

AbstractMolecular imaging possesses the ability to characterize and measure biological processes at the cellular and molecular level in vivo. As one of the new molecular imaging modalities, bioluminescence tomography (BLT) is to reconstruct the light distribution inside a small animal from the photon flux measured on its surface. To obtain accurate and robust reconstruction, it needs a good understanding of the propagation of photons in biological tissues, which is referred to as the forward problem in BLT. Because the turbid media is high scattering and low absorption, the propagation process can be described by the steady diffusion equation. In this paper, an hp‐adaptivity method for BLT forward problem is presented based on finite elements of high orders and moderate meshes by finite element method (FEM). Both numerical simulation and physical experiment are performed to evaluate the accuracy of solution and the efficiency of computation. The relevant results show that element order is more critical than mesh size to produce an accurate FEM solution efficiently. Copyright © 2008 John Wiley & Sons, Ltd.
Low power switched‐current circuits with low sensitivity to the rise/fall time of the clock
Authors: Rudnicki Radek , Kropidłowski Marek , Handkiewicz Andrzej 
Published: December 2008

AbstractThe switched‐current (SI) technique permits realizing analog discrete‐time circuits in standard digital CMOS technology. A very important property of the analog part of a system on a chip is the possibility it offers for realizing some functions of a digital circuit, but with reduced power consumption. In this paper, a low power SI integrator is presented. It is shown that an integrator consuming a fraction of a milliwatt can be designed in 0.35µm CMOS technology with the use of narrow transistor channels, and with the channel length as a design parameter. The impact of the rise/fall time of the clock signal on the integrator operation is observed. It is shown that this effect can be reduced when the proper switch dimensions are taken for the integrator. Analysis and measurements of the integrator noise are presented. The integrator was built with equal size transistors, yielding less sensitivity to variations in production parameters. An experimental chip in 0.35µm CMOS technology was fabricated, and measurements are compared with results obtained during analysis and simulations. In order to verify the properties of the designed integrator experimentally, a first‐order filter is built with the use of elementary cells on the chip. Copyright © 2008 John Wiley & Sons, Ltd.
Insight into the microbial multicellular lifestyle via flow‐cell technology and confocal microscopy
Authors: Pamp Sünje Johanna , Sternberg Claus , Tolker‐Nielsen Tim 
Published: December 2008

AbstractBiofilms are agglomerates of microorganisms surrounded by a self‐produced extracellular matrix. During the last 10 years, there has been an increasing recognition of biofilms as a highly significant topic in microbiology with relevance for a variety of areas in our society including the environment, industry, and human health. Accordingly a number of biofilm model systems, molecular tools, microscopic techniques, and image analysis programs have been employed for the study of biofilms under controlled and reproducible conditions. Studies using confocal laser scanning microscopy (CLSM) of biofilms formed in flow‐chamber experimental systems by genetically color‐coded bacteria have provided detailed knowledge about biofilm developmental processes, cell differentiations, spatial organization, and function of laboratory‐grown biofilms, in some cases down to the single cell level. In addition, the molecular mechanisms underlying the increased tolerance that biofilm cells often display towards antibiotic treatment are beginning to be unravelled. © 2008 International Society for Advancement of Cytometry
Die hard: Are cancer stem cells the Bruce Willises of tumor biology?
Authors: Fábián Ákos , Barok Márk , Vereb György , Szöllősi János 
Published: December 2008

AbstractIn recent years, an exponentially growing number of studies have focused on identifying cancer stem cells (CSC) in human malignancies. The rare CSCs could be crucial in controlling and curing cancer: through asymmetric division CSCs supposedly drive tumor growth and evade therapy with the help of traits shared with normal stem cells such as quiescence, self‐renewal ability, and multidrug resistance pump activity. Here, we give a brief overview of techniques used to confirm the stem cell‐like behavior of putative CSCs and discuss markers and methods for identifying, isolating, and culturing them. We touch on the limitations of each marker and why the combined use of CSC markers, in vitro and in vivo assays may still fail to identify all relevant CSC populations. Finally, the various experimental findings supporting and contradicting the CSC hypothesis are summarized. The large number of tumor types thus far with a subpopulation of uniquely tumorigenic and therapy resistant cells suggests that despite the unanswered questions and inconsistencies, the CSC hypothesis has a legitimate role to play in tumor biology. At the same time, experimental evidence supporting the established alternative theory of clonal evolution can be found as well. Therefore, a model that describes cancer initiation and progression should combine elements of clonal evolution and CSC theory. © 2008 International Society for Advancement of Cytometry
Toward an Allosteric Metallated Container
Authors: Szelke Helga , Wadepohl Hubert , Abu‐Youssef Morsy , Krämer Roland 
Published: December 2008

AbstractPolytopic ligands L1 and L2 in which three 2,2′‐bipyridine units are linked to a central tris(pyrid‐2‐yl)amine (L1) or tris(pyrid‐2‐yl)methanol (L2) moiety by alkyl spacers were prepared by multistep organic syntheses. The parent tris(pyrid‐2‐yl)‐type ligands were shown to be modest‐to‐good chelators for Zn2+ and Cu2+ ions in solution, and bi‐ and tridentate N‐coordination was confirmed by crystal structures of CuII and RuII complexes, respectively. FeII and RuII smoothly form stable, cage‐like 1:1 complexes with L1 and L2, in which the metal ion is coordinated to the tris(bpy) site of the ligands. The vacant tris(pyrid‐2‐yl) site of these complexes is, however, a poor donor site for Zn2+ and Cu2+ ions. In addition, FeII modulates the coordination behaviour of the tris(pyrid‐2‐yl) site toward Zn2+: Whereas tris(5‐methylpyrid‐2‐yl)amine forms a 2:1 complex with Zn2+ in CH2Cl2, [Fe(L1)]2+ forms a 1:1 Zn complex. Spectrophotometric titrations suggest that [Fe(L2)]2+ forms a polynuclear Zn2+ complex in CH2Cl2, possibly involving bridging coordination of the alcohol OH group, which contrasts the smooth formation of a 2:1 complex of the parent tris(pyrid‐2‐yl)‐type ligand with Zn. FeII might therefore be considered as an allosteric effector, which modulates the metal binding properties of the second tris(pyrid‐2‐yl) site of L1 and L2. Contrary to expectation, Zn2+ and Cu2+ appear to associate weakly with donor atoms directed toward the exterior of the cage‐like complexes [Fe(Ln)]2+ and [Ru(L1)]2+, rather than locating in the interior of the container by tripodal coordination to the tris(pyrid‐2‐yl) site.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Group 4 Metal Complexes That Contain a Thioether‐Functionalized Phenolato Ligand: Synthesis, Structure, and 1‐Hexene Polymerization
Authors: Lian Bing , Beckerle Klaus , Spaniol Thomas P. , Okuda Jun 
Published: December 2008

AbstractReaction of group 4 metal tetrabenzyl complexes [M(CH2Ph)4] (M = Ti, Zr, Hf) with 1 or 2 equiv. of a thioether‐functionalized phenol 2,4‐tBu2‐6‐(PhSCH2)C6H2OH afforded dibenzyl complexes [M(L)2(CH2Ph)2] (M = Ti, 1; M = Zr, 2; M = Hf, 3) and the tribenzyl zirconium complex [Zr(L)(CH2Ph)3] (4). Benzyl abstraction with a Lewis acid gave the zirconium monobenzyl cation [Zr(L)2CH2Ph]+[PhCH2B(C6F5)3]– (5) and the dibenzyl cation [Zr(L)(CH2Ph)2]+[PhCH2B(C6F5)3]– (6). The monobenzyl cation 5 oligomerized 1‐hexene to low molecular‐weight atactic oligo(1‐hexene) (Mn = 560–820), while the dibenzyl cation 6 polymerized 1‐hexene isospecifically ([mmmm] > 90 %). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)