bluuebunny/crossref_metadata_2025_split huggingface dataset:
Novel poly(L‐lactic acid)/hyaluronic acid macroporous hybrid scaffolds: Characterization and assessment of cytotoxicity
Authors: Antunes J. C. , Oliveira J. M. , Reis R. L. , Soria J. M. , Gómez‐Ribelles J. L. , Mano J. F. 
Published: March 2010

AbstractPoly(L‐lactic acid), PLLA, a synthetic biodegradable polyester, is widely accepted in tissue engineering. Hyaluronic acid (HA), a natural polymer, exhibits an excellent biocompatibility, influences cell signaling, proliferation, and differentiation. In this study, HA crosslinking was performed by immersion of the polysaccharide in water–acetone mixtures containing glutaraldehyde (GA). The objective of this work is to produce PLLA scaffolds with the pores coated with HA, that could be beneficial for bone tissue engineering applications. PLLA tridimensional scaffolds were prepared by compression molding followed by salt leaching. After the scaffolds impregnation with soluble HA solutions of distinct concentration, a GA‐crosslinking reaction followed by inactivation of the unreacted GA with glycine was carried out. An increase on surface roughness is shown by scanning electron microscopy (SEM) with the addition of HA. Toluidine blue staining indicates the present of stable crosslinked HA. An estimation of the HA original weight in the hybrid scaffolds was performed using thermal gravimetric analyses. FTIR‐ATR and XPS confirmed the crosslinking reaction. Preliminary in vitro cell culture studies were carried out using a mouse lung fibroblast cell line (L929). SEM micrographs of L929 showed that cells adhered well, spread actively throughout all scaffolds, and grew favorably. A MTS test indicated that cells were viable when cultured onto the surface of all scaffolds, suggesting that the introduction of crosslinked HA did not increase the cytotoxicity of the hybrid scaffolds. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010
Three‐dimensional macroscopic scaffolds with a gradient in stiffness for functional regeneration of interfacial tissues
Authors: Singh Milind , Dormer Nathan , Salash Jean R. , Christian Jordan M. , Moore David S. , Berkland Cory , Detamore Michael S. 
Published: March 2010

AbstractA novel approach has been demonstrated to construct biocompatible, macroporous 3‐D tissue engineering scaffolds containing a continuous macroscopic gradient in composition that yields a stiffness gradient along the axis of the scaffold. Polymeric microspheres, made of poly(D,L‐lactic‐co‐glycolic acid) (PLGA), and composite microspheres encapsulating a higher stiffness nano‐phase material (PLGA encapsulating CaCO3 or TiO2 nanoparticles) were used for the construction of microsphere‐based scaffolds. Using controlled infusion of polymeric and composite microspheres, gradient scaffolds displaying an anisotropic macroscopic distribution of CaCO3/TiO2 were fabricated via an ethanol sintering technique. The controllable mechanical characteristics and biocompatible nature of these scaffolds warrants further investigation for interfacial tissue engineering applications. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010
Mussel adhesive protein fused with cell adhesion recognition motif triggers integrin‐mediated adhesion and signaling for enhanced cell spreading, proliferation, and survival
Authors: Kim Bum Jin , Choi Yoo Seong , Choi Bong‐Hyuk , Lim Seonghye , Song Young Hoon , Cha Hyung Joon 
Published: March 2010

AbstractAdhesion of cells to a surface is a basic and important requirement in the fields of cell culture and tissue engineering. Previously, we constructed the cell adhesive, fp‐151‐RGD, by fusion of the hybrid mussel adhesive protein, fp‐151, and GRGDSP peptide, one of the major cell adhesion recognition motifs; fp‐151‐RGD efficiently immobilized cells on coated culture surfaces with no protein and surface modifications, and apparently enhanced cell adhesion, proliferation, and spreading abilities. In the present study, we investigated the potential use of fp‐151‐RGD as a biomimetic extracellular matrix material at the molecular level by elucidating its substantial effects on integrin‐mediated adhesion and signaling. Apoptosis derived from serum deprivation was significantly suppressed on the fp‐151‐RGD‐coated surface, indicating that RGD‐induced activation of integrin‐mediated signaling triggers the pathway for cell survival. Analysis of the phosphorylation of focal adhesion kinase clearly demonstrated activation of focal adhesion kinase, a well‐established indicator of integrin‐mediated signaling, on the fp‐151‐RGD‐coated surface, leading to significantly enhanced cell behaviors, including proliferation, spreading and survival, and consequently, more efficient cell culture. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010
Preparation and tribological properties of polyetheretherketone composites
Authors: Xiong Dangsheng , Xiong Lei , Liu LingLing 
Published: March 2010

AbstractPolyetheretherketone (PEEK) is a thermoplastic engineering plastic with excellent mechanical properties. In this article, PEEK and its composites filled with ultrahigh‐molecular‐weight polyethylene (UHMWPE) were prepared by vacuum hot‐pressing method. Tribological properties of these materials were investigated by block‐on‐ring friction and wear rig. An alloy (CoCrMo) ring and a ceramic (Si3N4) ring were used as friction pairs. The experiments were conducted under deionized water lubrication (DWL), saline lubrication (SL), and calf serum solution lubrication (CSSL). Worn surfaces morphology was observed and analyzed by metallographic microscope. The results indicated that friction coefficients of PEEK/UHMWPE composites were effectively reduced when compared with pure PEEK. When the materials slid against the alloy (CoCrMo) ring, wear rates of PEEK/UHMWPE were also effectively reduced when compared with pure PEEK. Wear mechanisms of PEEK were mainly ploughing and slight scratches under CSSL condition, whereas the quantity of the ploughing and scratches for PEEK/20%UHMWPE were significantly reduced. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010
Initial evaluation of bone ingrowth into a novel porous titanium coating
Authors: Wazen Rima M. , Lefebvre Louis‐Philippe , Baril Eric , Nanci Antonio 
Published: March 2010

AbstractPorous metals (sintered beads and meshes) have been used for many years for different orthopedic applications. Metal foams have been recently developed. These foams have the advantage of being more porous than the traditional coatings. Their high porosity provides more space for bone ingrowth and mechanical interlocking and presents more surface for implant‐bone contact. The objective of this study was to evaluate in vivo bone ingrowth into Ti implants covered with a novel Ti foam coating. This foam contains 50% in volume of interconnected pores and a higher surface area compared to dense Ti. Both coated implants and dense Ti controls were placed transcortically in the rat tibia. The animals were sacrificed at 2 weeks after implantation, and the amount of bone in the implants was determined using backscattered electron imaging and X‐ray microtomography. Already at this time interval, the pores within the Ti foam showed 97.7% bone filling, and the bone‐implant contact area was significantly increased compared to dense Ti controls. These initial results indicate that this novel Ti foam is biocompatible, has the capacity to sustain bone formation, and can potentially improve osseointegration. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010
More insights into the CCN3/Connexin43 interaction complex and its role for signaling
Authors: Gellhaus Alexandra , Wotzlaw Christoph , Otto Teresa , Fandrey Joachim , Winterhager Elke 
Published: March 2010

AbstractConnexin43 (Cx43) forms gap junction channels but also serves as a signaling center by binding to proteins via its C‐terminus. We have previously demonstrated that transfection of Cx43 leads to significantly reduced proliferation of placental tumor cells through upregulating and binding of the growth regulator CCN3 (NOV) at the C‐terminus of Cx43. Here, we combined fluorescence resonance energy transfer (FRET), co‐immunoprecipitation and proliferation and expression assays to characterize the interaction complex of Cx43 and CCN3. FRET measurements confirmed the interaction of CCN3 with wild‐type Cx43 (amino acids 1‐382) and with mutants of Cx43 truncated at the C‐terminus resulting in Cx43 proteins of amino acids 1‐374, 1‐273, 1‐264, 1‐257 in 293T cells. These results matched the co‐immunoprecipitation data. Interestingly, although FRET revealed distinct efficiencies in interaction of Cx43 with CCN3 for all deletion constructs only wild‐type Cx43 and one deletion construct (1‐374) led to increased CCN3 expression. Only these interactions which were associated with increased CCN3 expression resulted in a reduced cell proliferation. Our study provides evidence that only defined binding properties between Cx43 and CCN3 leading to an upregulation of CCN3 are needed for signaling. Furthermore, the data obtained by FRET analysis allowed us to model the 3D structure of the C‐terminus of Cx43 interacting with CCN3. J. Cell. Biochem. 110: 129–140, 2010. © 2010 Wiley‐Liss, Inc.
FGF signalling as a mediator of lineage transitions—Evidence from embryonic stem cell differentiation
Authors: Villegas Santiago Nahuel , Canham Maurice , Brickman Joshua M. 
Published: March 2010

AbstractThe fibroblast growth factor (FGF) signalling pathway is one of the most ubiquitous in biology. It has diverse roles in development, differentiation and cancer. Embryonic stem (ES) cells are in vitro cell lines capable of differentiating into all the lineages of the conceptus. As such they have the capacity to differentiate into derivatives of all three germ layers and to some extent the extra‐embryonic lineages as well. Given the prominent role of FGF signalling in early embryonic development, we explore the role of this pathway in early ES cell differentiation towards the major lineages of the embryo. As early embryonic differentiation is intricately choreographed at the level of morphogenetic movement, adherent ES cell culture affords a unique opportunity to study the basic steps in early lineage specification in the absence of ever shifting complex in vivo microenvironments. Thus recent experiments in ES cell differentiation are able to pinpoint specific FGF dependent lineage transitions that are difficult to resolve in vivo. Here we review the role of FGF signalling in early development alongside the ES cell data and suggest that FGF dependent signalling via phospho‐Erk activation maybe a major mediator of transitions in lineage specification. J. Cell. Biochem. 110: 10–20, 2010. © 2010 Wiley‐Liss, Inc.
Up‐regulation of crystallins is involved in the neuroprotective effect of wolfberry on survival of retinal ganglion cells in rat ocular hypertension model
Authors: Chiu Kin , Zhou Yuan , Yeung Sze‐Chun , Lok Carmen Ka‐Ming , Chan Owen O‐Cheung , Chang Raymond Chuen‐Chung , So Kwok‐Fai , Chiu Jin‐Fu 
Published: March 2010

AbstractWolfberry (fruit of Lycium barbarum Linn) has been known for balancing ‘Yin’ and ‘Yang’ in the body, nourishing the liver and kidney, improving visual acuity for more than 2,500 years in oriental countries. The active components in wolfberry include L. barbarum polysaccharide (LBP), zeaxanthine, betaine, cerebroside and trace amounts of zinc, iron, and copper. Each of them confers distinct beneficial effects and together they help to explain widespread use of wolfberry in the eastern world. Earlier study reported the neuroprotective effects of LBP on retinal ganglion cell (RGC) in an experimental model of glaucoma and the underlying in vivo cellular mechanisms of LBP neuroprotection deserve further exploration. In this study, we adopted proteomics, functional genomics, to evaluate pharmacological effects of LBP on the neuronal survival pathways. Among the significantly changed proteins induced by LBP feeding on ocular hypertension (OH) retinas, only proteins in crystallin family were focused in this study. The proteomic results were further confirmed using the Western blotting of the retinas and immunohistochemical staining of the retinal sections. We demonstrated that neuroprotective effect of—wolfberry extract—LBP on the survival of RGCs may be mediated via direct up‐regulation of neuronal survival signal βB2‐crystallin. J. Cell. Biochem. 110: 311–320, 2010. © 2010 Wiley‐Liss, Inc.
Tissue geometry patterns epithelial–mesenchymal transition via intercellular mechanotransduction
Authors: Gomez Esther W. , Chen Qike K. , Gjorevski Nikolce , Nelson Celeste M. 
Published: March 2010

AbstractEpithelial–mesenchymal transition (EMT) is a phenotypic change in which epithelial cells detach from their neighbors and become motile. Whereas soluble signals such as growth factors and cytokines are responsible for stimulating EMT, here we show that gradients of mechanical stress define the spatial locations at which EMT occurs. When treated with transforming growth factor (TGF)‐β, cells at the corners and edges of square mammary epithelial sheets expressed EMT markers, whereas those in the center did not. Changing the shape of the epithelial sheet altered the spatial pattern of EMT. Traction force microscopy and finite element modeling demonstrated that EMT‐permissive regions experienced the highest mechanical stress. Myocardin‐related transcription factor (MRTF)‐A was localized to the nuclei of cells located in high‐stress regions, and inhibiting cytoskeletal tension or MRTF‐A expression abrogated the spatial patterning of EMT. These data suggest a causal role for tissue geometry and endogenous mechanical stresses in the spatial patterning of EMT. J. Cell. Biochem. 110: 44–51, 2010. © 2010 Wiley‐Liss, Inc.
17β‐estradiol supplementation attenuates ovariectomy‐induced increases in ATGL signaling and reduced perilipin expression in visceral adipose tissue
Authors: Wohlers Lindsay M. , Spangenburg Espen E. 
Published: March 2010

AbstractAdipocytes from post‐menopausal females have higher basal lipolytic rates than pre‐menopausal females, which contributes to increased risk of developing dyslipidemia following menopause. The purpose of this study was to delineate cellular mechanisms affecting adipose tissue function in the ovariectomized (OVX) mouse and also determine if physical activity or estrogen supplementation alter any detected changes. Female C57/Bl6 mice were placed into SHAM, OVX sedentary (OVX), OVX exercise (OVX‐Ex), and OVX sedentary + 17β‐estradiol (OVX + E2) groups. Visceral fat mass, glycerol, and NEFA levels were significantly higher in OVX mice compared to SHAM animals, but were not elevated in the E2‐treated animals. Voluntary running failed to change circulating levels of glycerol or NEFA in OVX mice, but did partially attenuate the increase in visceral fat mass. Adipose triglyceride lipase (ATGL) protein content was significantly elevated in visceral fat from OVX and OVX‐Ex groups compared to SHAM, while ATGL–CGI‐58 interaction was significantly higher in OVX than SHAM and OVX + E2 mice. No significant differences in HSL phosphorylation were detected between groups, however, ERK1/2 phosphorylation was significantly elevated in the OVX mice. To determine if ERK1/2 function was critical for the increased glycerol levels, visceral fat was treated with MEK inhibitor PD98059, with no differences in glycerol release detected. Perilipin protein content was decreased significantly in OVX and OVX‐Ex mice compared to SHAM. Thus, these data suggest that increased ATGL signaling and reduced perilipin protein content may contribute to increased NEFA and glycerol levels in OVX mice, which are attenuated with E2 treatment, but not by exercise. J. Cell. Biochem. 110: 420–427, 2010. © 2010 Wiley‐Liss, Inc.
Hypoxia decreases sclerostin expression and increases Wnt signaling in osteoblasts
Authors: Genetos Damian C. , Toupadakis Chrisoula A. , Raheja Leah F. , Wong Alice , Papanicolaou Savvas E. , Fyhrie David P. , Loots Gabriela G. , Yellowley Clare E. 
Published: March 2010

AbstractMutations in sclerostin function or expression cause sclerosing bone dysplasias, involving decreased antagonism of Wnt/Lrp5 signaling. Conversely, deletion of the VHL tumor suppressor in osteoblasts, which stabilize HIF‐α isoforms and thereby enables HIF‐α/β‐driven gene transcription, increases bone mineral content and cross‐sectional area compared to wild‐type controls. We examined the influence of cellular hypoxia (1% oxygen) upon sclerostin expression and canonical Wnt signaling. Osteoblasts and osteocytes cultured under hypoxia revealed decreased sclerostin transcript and protein, and increased expression and nuclear localization of activated β‐catenin. Similarly, both hypoxia and the hypoxia mimetic DFO increased β‐catenin gene reporter activity. Hypoxia and its mimetics increased expression of the BMP antagonists gremlin and noggin and decreased Smad‐1/5/8 phosphorylation. As a partial explanation for the mechanism of regulation of sclerostin by oxygen, MEF2 reporter assays revealed decreased activity. Modulation of VEGF signaling under normoxia or hypoxia revealed no influence upon Sost transcription. These data suggest that hypoxia inhibits sclerostin expression, through enhanced antagonism of BMP signaling independent of VEGF. J. Cell. Biochem. 110: 457–467, 2010. © 2010 Wiley‐Liss, Inc.
More is less: Inactivation and deletion events and the search for tumor suppressor genes
Authors: Bradley W. Edward C. , Di Paola Domenic , Rampakakis Emmanouil , Zannis‐Hadjopoulos Maria 
Published: March 2010

AbstractTumor suppressor genes are frequently inactivated in cancer by large‐scale deletion events or epigenetic silencing, and experimental demonstration of such inactivation has historically been considered as support for assigning tumor suppressive function to a given gene. However, the discovery of a number of chromosomal domains wherein large deletions naturally occur at frequencies up to 100 times the average for the genome as a whole leads us to reevaluate the significance of sporadic deletions found within genes associated with these hotspots. Similarly, our recent demonstration that epigenetic chromatin silencing frequently spreads in cancer cells from gene‐poor into gene‐rich regions with apparent indifference to the gene content of the affected domain raises questions about the pertinence of inactivation as a criterion for ascribing tumor suppressor function to a given gene. We suggest that a number of putative suppressor genes for which inactivation and/or deletion events have been documented may simply be victims of collateral damage when these events occur, and the implication that these genes are being selected against during cancer progression should in some cases be reassessed. J. Cell. Biochem. 110: 281–287, 2010. © 2010 Wiley‐Liss, Inc.
Commentaries on quantum similarity (1): Density gradient quantum similarity
Authors: Carbó‐Dorca Ramon , Mercado Luz Dary 
Published: March 2010

AbstractComputation of density gradient quantum similarity integrals is analyzed, while comparing such integrals with overlap density quantum similarity measures. Gradient quantum similarity corresponds to another kind of numerical similarity assessment between a pair of molecular frames, which contrarily to the usual up to date quantum similarity definitions are not measures, that is: strictly positive definite integrals. As the density gradient quantum similarity integrals are defined as scalar products of three real functions, they appear to possess a richer structure than the corresponding positive definite density overlap quantum similarity measures, while preserving the overall similarity trends, when the molecular frames are relatively moved in three‐dimensional space. Similarity indices are also studied when simple cases are analyzed in order to perform more comparisons with density overlap quantum similarity. Multiple gradient quantum similarity integrals are also defined. General GTO formulae are given. Numerical results within the atomic shell approximation (ASA) framework are presented as simple examples showing the new performances of the gradient density quantum similarity. Fortran 90 programs illustrating the proposed theoretical development can be downloaded from appropriate websites. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2010
ForceFit: A code to fit classical force fields to quantum mechanical potential energy surfaces
Authors: Waldher Benjamin , Kuta Jadwiga , Chen Samuel , Henson Neil , Clark Aurora E. 
Published: March 2010

AbstractThe ForceFit program package has been developed for fitting classical force field parameters based upon a force matching algorithm to quantum mechanical gradients of configurations that span the potential energy surface of the system. The program, which runs under UNIX and is written in C++, is an easy‐to‐use, nonproprietary platform that enables gradient fitting of a wide variety of functional force field forms to quantum mechanical information obtained from an array of common electronic structure codes. All aspects of the fitting process are run from a graphical user interface, from the parsing of quantum mechanical data, assembling of a potential energy surface database, setting the force field, and variables to be optimized, choosing a molecular mechanics code for comparison to the reference data, and finally, the initiation of a least squares minimization algorithm. Furthermore, the code is based on a modular templated code design that enables the facile addition of new functionality to the program. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2010
Modeling of diarylalkyl‐imidazole and diarylalkyl‐triazole derivatives as potent aromatase inhibitors for treatment of hormone‐dependent cancer
Authors: Nagar Shuchi , Saha Achintya 
Published: March 2010

AbstractAromatase is an enzyme that catalyzes the final step in the conversion of androgen to estrogen. It has become an attractive target for the treatment of estrogen responsive breast cancer. The study has been focused on designing aromatase inhibitors (AIs) that can be selected as probable drug candidate for the treatment of breast cancer. In the present study, long chain diarylalkyl‐imidazole and ‐triazole scaffolds have been considered for exploring pharmacophores as potent AIs using QSAR (Quantitative SAR) and pharmacophore mapping studies. The model generated in linear free energy QSAR study (R2 = 0.905, Q2= 0.885, R2pred(ts) = 0.763) showed the importance of hydrophobicity, size and shape of the molecule, van der Waals surface and hydrogen atom contribution influence the activity. 3D QSAR of comparative molecular field analysis (CoMFA, R2= 0.921, Q2 = 0.741, R2pred(ts)= 0.583) showed that steric and electrostatic features along with hydrophobicity and electronic charge contribution at C4 (Fig. 1) influence on the inhibitory activity. Comparative molecular similarity analysis (CoMSIA, R2 = 0.874, Q2 = 0.716, R2pred(ts) = 0.591) study adjudged the presence of steric, electrostatic and hydrophobic fields together with hydrogen bond (HB) donor and acceptor play significant role in inhibitory activity to aromatase enzyme. Further pharmacophore mapping study (Q2 = 0.947, Δcost = 113.171, R2pred(ts) = 0.857) suggested that presence of HB acceptor, hydrophobicity with aromatic ring, and the importance of steric contribution influence on the activity. The critical distances among the features are also important for the inhibitor activity. © 2010 Wiley Periodicals, Inc. J Comput Chem, 2010