bluuebunny/crossref_metadata_2025_split huggingface dataset:
The ECM protein LTBP‐2 is a suppressor of esophageal squamous cell carcinoma tumor formation but higher tumor expression associates with poor patient outcome
Authors: Chan Stephen Ho Kin , Yee Ko Josephine Mun , Chan Kwok Wah , Chan Yuen Piu , Tao Qian , Hyytiainen Marko , Keski‐Oja Jorma , Law Simon , Srivastava Gopesh , Tang Johnny , Tsao Sai Wah , Chen Han , Stanbridge Eric J. , Lung Maria Li 
Published: September 2010

AbstractOur previous studies of chromosome 14 transfer into tumorigenic esophageal squamous cell carcinoma (ESCC) cell line, SLMT, suggested the existence of tumor suppressor genes on chromosome 14. Gene expression profiling of microcell hybrids and the tumor segregants identified an interesting gene, LTBP‐2 (latent transforming growth factor β binding protein 2), which has been analyzed here for its role in ESCC. LTBP‐2 maps to 14q24 and encodes a secreted protein, which is a component of the extracellular matrix microfibrils. LTBP‐2 expression was downregulated in ESCC cell lines and tumor tissues. Promoter hypermethylation was found to be involved in LTBP‐2 inactivation. Functional studies indicated its tumor‐suppressive roles in ESCC. In the in vitro colony formation and Matrigel three‐dimensional culture assays, LTBP‐2 decreased the colony‐forming abilities of ESCC cell lines. LTBP‐2 expression was associated with reduction of cell migrating and invasive abilities. LTBP‐2 could also reduce the tube‐forming ability of endothelial cells. Moreover, LTBP‐2 induced tumor suppression in in vivo nude mouse assays. Tissue microarray immunohistochemical staining analysis indicated that LTBP‐2 expression is reduced in tumor tissues when compared to normal tissues, and LTBP‐2 expression correlated significantly with the survival of ESCC patients. Thus, LTBP‐2 appears to play an important role in ESCC.
Biomimetic matrices for myocardial stabilization and stem cell transplantation
Authors: Wall Samuel T. , Yeh Che‐Chung , Tu Richard Y. K. , Mann Michael J. , Healy Kevin E. 
Published: September 2010

AbstractAlthough natural biological matrices have demonstrated modest improvement in the survival of cells transplanted into the infarcted myocardium, these materials have not been amenable to systematic optimization and therefore have limited potential to treat postinfarct cardiac injuries. Here we have developed tunable bioactive semi‐interpenetrating polymer network (sIPN) hydrogels with matrix metalloproteinase (MMP) labile crosslinkers to be used as an assistive microenvironment for transplantation of bone marrow‐derived mesenchymal stem cells (BMSCs) into the infarcted myocardium. Injectable sIPN hydrogels were designed with a range of mechanical and biological properties that yielded material‐dependent BMSC proliferation in vitro. Five groups were evaluated to treat myocardial infarction (MI) in adult mice: saline injection; green fluorescent protein (GFP)(+)‐BMSCs delivered in saline; a sIPN matrix; a sIPN + GFP(+)‐BMSCs; and Matrigel™ + GFP(+)‐BMSCs. Injection of cells alone created a transient improvement in LV function that declined over time, and the synthetic hydrogel without cells resulted in the highest LV function at 6 weeks. Donor GFP‐positive cells were detected after matrix‐enhanced transplantation, but not without matrix support. Biomimetic sIPN hydrogel matrices succeeded both in mechanically supporting the injured myocardium and modestly enhancing donor cell survival. These matrices provide a foundation for systematic development of “pro‐survival” microenvironments, and improvement in the long‐term results of cardiac stem cell transplantation therapies. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.
Keratin–hydroxyapatite composites: Biocompatibility, osseointegration, and physical properties in an ovine model
Authors: Dias George J. , Mahoney Patricia , Swain Michael , Kelly Robert J. , Smith Robert A. , Ali Mohammad A. 
Published: September 2010

AbstractReconstituted keratin has shown promise as an orthopaedic biomaterial. Thisin vivostudy investigates the biological response of composite materials prepared from reconstituted keratin containing a high content of hydroxyapatite (HA) (40 wt % HA), implanted for up to 18 weeks in the long bones of sheep. Keratin–HA composites were compared with a commercially available polylactic acid (PLA) HA composite (BIO RCI HA®, Smith and Nephew). Porous keratin–HA materials displayed excellent biocompatibility and osseointegration, with full integration into bone by 12 weeks. Dense keratin–HA materials also showed excellent biocompatibility, with a more limited osseointegration, involving the penetration of new bone into the periphery of the implant after eight weeks. In contrast, the PLA–HA implant did not integrate with surrounding tissue. Microindentation showed that porous keratin–HA implants were initially soft, but became stiffer as new bone penetrated the implant from four weeks onwards. In contrast, although the initial rigidity of dense keratin–HA composites was maintained for at least two weeks, the implant material weakened after four weeks. The PLA–HA implant maintained its physical properties throughout the course of the trial. This study demonstrates the increased osseointegration/osteoconduction capacity of keratin–HA composites and provides further evidence supporting the suitability of keratin‐based materials, such as bone graft substitutes and soft tissue fixation devices. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.
Toward biomimetic materials in bone regeneration: Functional behavior of mesenchymal stem cells on a broad spectrum of extracellular matrix components
Authors: Ode Andrea , Duda Georg N. , Glaeser Juliane D. , Matziolis Georg , Frauenschuh Simone , Perka Carsten , Wilson Cameron J. , Kasper Grit 
Published: September 2010

AbstractBone defect treatments can be augmented by mesenchymal stem cell (MSC) based therapies. MSC interaction with the extracellular matrix (ECM) of the surrounding tissue regulates their functional behavior. Understanding of these specific regulatory mechanisms is essential for the therapeutic stimulation of MSC in vivo. However, these interactions are presently only partially understood. This study examined in parallel, for the first time, the effects on the functional behavior of MSCs of 13 ECM components from bone, cartilage and hematoma compared to a control protein, and hence draws conclusions for rational biomaterial design. ECM components specifically modulated MSC adhesion, migration, proliferation, and osteogenic differentiation, for example, fibronectin facilitated migration, adhesion, and proliferation, but not osteogenic differentiation, whereas fibrinogen enhanced adhesion and proliferation, but not migration. Subsequently, the integrin expression pattern of MSCs was determined and related to the cell behavior on specific ECM components. Finally, on this basis, peptide sequences are reported for the potential stimulation of MSC functions. Based on the results of this study, ECM component coatings could be designed to specifically guide cell functions. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.
Biocompatibility and bioactivity of designer self‐assembling nanofiber scaffold containing FGL motif for rat dorsal root ganglion neurons
Authors: Zou Zhenwei , Zheng Qixin , Wu Yongchao , Guo Xiaodong , Yang Shuhua , Li Jingfeng , Pan Haitao 
Published: September 2010

AbstractWe report here a designer self‐assembling peptide nanofiber scaffold developed specifically for nerve tissue engineering. We synthesized a peptide FGL‐RADA containing FGL (EVYVVAENQQGKSKA), the motif of neural cell adhesion molecule (NCAM), and then attended to make a FGL nanofiber scaffold (FGL‐NS) by assembling FGL‐RADA with the peptide RADA‐16 (AcN‐RADARADARADARADA‐CONH2). The microstructures of the scaffolds were tested using atomic force microscopy (AFM), and rheological properties of materials were accessed. Then we demonstrated the biocompatibility and bioactivity of FGL‐NS for rat dorsal root ganglion neurons (DRGn). We found that the designer self‐assembling peptide scaffold was noncytotoxic to neurons and able to promote adhesion and neurite sprouting of neurons. Our results indicate that the designer peptide scaffold containing FGL had excellent biocompatibility and bioactivity with adult sensory neurons and could be used for neuronal regeneration. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.
Augmentation of postswelling surgical sealant potential of adhesive hydrogels
Authors: Shazly Tarek M. , Baker Aaron B. , Naber John R. , Bon Adriana , Van Vliet Krystyn J. , Edelman Elazer R. 
Published: September 2010

AbstractTwo‐component hydrogels formed with star polyethylene glycol amine and linear dextran aldehyde polymers (PEG:dextran) show promise as tissue‐specific surgical sealants. However, there is a significant loss of adhesion strength to soft tissues following PEG:dextran swelling, which may limit material ability to appose disjoined tissues and prevent leakage from surgical sites. We covalently incorporated the modified amino acid L‐3,4‐dihydroxyphenylalanine (L‐DOPA) into PEG:dextran to enhance postswelling sealant performance. L‐DOPA is an essential component of marine animal adhesive plaques and has been used to confer wet adhesion in synthetic materials. As both PEG:dextran cohesion and adhesion are mediated by aldehyde‐amine interactions, L‐DOPA side‐groups make it a potent network modulator with potential to affect multiple material properties. Following 1‐h submersion in aqueous media, PEG:dextran doped with 3 mM
L‐DOPA/M aldehyde on average swelled 50.3% less, had 287.4% greater stiffness, and had 53.6% greater functional adhesion strength compared to the neat hydrogel. Increased concentrations of L‐DOPA up to 11 mM
L‐DOPA/M aldehyde similarly curtailed swelling and mitigated property loss with hydration, but sacrificed initial functional adhesion strength, material modulus, and biocompatibility. Taken together, these data support tailored L‐DOPA conjugation as a promising approach to enhance the clinical performance of PEG:dextran sealants. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2010.
Modulation of mesenchymal stem cells behaviors by chitosan/gelatin/pectin network films
Authors: Li Junjie , Sun Hong , Zhang Rui , Li Ruyue , Yin Yuji , Wang Hui , Liu Yuxi , Yao Fanglian , Yao Kangde 
Published: September 2010

AbstractIn this article, the chitosan/gelatin/pectin (CGP) network films were prepared to build appropriate physicochemical and mechanical microenvironment for attachment, proliferation, and differentiation of mesenchymal stem cells (MSCs). Results suggested that the hydrophilicity and mechanical character of CGP composites films could be modulated via adjusting the pectin content in the composites. The investigations of attachment and proliferation behaviors of mesenchymal stem cells (MSCs) on the CGP films were carried out. The morphology of cells was observed with hematoxylin/eosin staining (HE) and scanning electron microscope (SEM). The osteogenic differentiation of MSCs was investigated via ALP and polymerase chain reaction (PCR). Results suggested that the CGP films have excellent biocompatibility. MSCs seeded on CGP (0.1) film show higher proliferation capacity compared with other samples. Moreover, osteogenic differentiation of MSCs also depends on the properties of the substrate. The MSCs seeded on CGP (0.5) expressed the highest ALP activity, osteogenic gene expression and mineral formation capacity. These results suggest that the composition of the CGP network films could effectively modulate their physicochemical and mechanical properties and further regulate the cell behaviors of MSCs. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010.
Comparison of MTT assay, flow cytometry, and RT‐PCR in the evaluation of cytotoxicity of five prosthodontic materials
Authors: Wang Xue , Xia Yang , Liu Laikui , Liu Mei , Gu Ning , Guang Hanbing , Zhang Feimin 
Published: September 2010

AbstractIn the present study, the cytotoxic effects of five prosthodontic materials on the L929 cell line were assessed by flow cytometry (FCM), reverse transcription PCR (RT‐PCR), and MTT (3‐(4,5‐dimethylthiazole‐2‐yl)‐2,5‐diphenyltetrazoli‐umbromide) assay. The cells were treated with eluates resin (RE), pressable ceramics (PC), Co‐Cr alloy‐porcelain (CC), Ni‐Cr alloy‐porcelain (NC), and diatomite ceramics (DC). The cytotoxicity of all the materials tested by the MTT assay was grade 1. By FCM analysis, apoptosis rates of DC and PC were low, with no significant difference from the control (p > 0.05). The rest of the groups induced much higher apoptosis rates (p < 0.05), with the highest in the RE group. The necrotic cell levels of RE was also significantly increased (p < 0.05). Bcl‐2 and Bax mRNA expression were determined by RT‐PCR, and the Bax/Bcl‐2 ratio in the DC and PC groups were not significantly different from the control (p > 0.05), whereas CC, NC, and RE groups showed significant differences (p < 0.05). Taken together, the results suggest that FCM and RT‐PCR analyses can supplement the traditional MTT assay in evaluating the cytotoxicity of prosthodontic materials for selecting highly biocompatible materials. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010.
In vitro evaluation of cytotoxicity of silver‐containing borate bioactive glass
Authors: Luo Shi‐Hua , Xiao Wei , Wei Xiao‐Juan , Jia Wei‐Tao , Zhang Chang‐Qing , Huang Wen‐Hai , Jin Dong‐Xu , Rahaman Mohamed N. , Day Delbert E. 
Published: September 2010

AbstractThe cytotoxicity of silver‐containing borate bioactive glass was evaluated in vitro from the response of osteoblastic and fibroblastic cells in media containing the dissolution products of the glass. Glass frits containing 0−2 weight percent (wt %) Ag were prepared by a conventional melting and quenching process. The amount of Ag dissolved from the glass into a simulated body fluid (SBF), measured using atomic emission spectroscopy, increased rapidly within the first 48 h, but slowed considerably at longer times. Structural and microchemical analysis showed that the formation of a hydroxyapatite‐like layer on the glass surface within 14 days of immersion in the SBF. The response of MC3T3‐E1 and L929 cells to the dissolution products of the glass was evaluated using SEM observation of cell morphology, and assays of MTT hydrolysis, lactate dehydrogenase release, and alkaline phosphatase activity after incubation for up to 48 h. Cytotoxic effects were found for the borate glass containing 2 wt % Ag, but not for 0.75 and 1 wt % Ag. This borate glass containing up to ∼1 wt % Ag could provide a coating material for bacterial inhibition and enhanced bioactivity of orthopaedic implant materials such as titanium. © 2010 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010.
Correction to: Complete enumeration of pure‐level and mixed‐level orthogonal arrays
Authors: Schoen Eric D. , Eendebak Pieter T. , Nguyen Man V. M. 
Published: September 2010

AbstractWe correct an error found in Schoen, Endebak, Nguyen, J Combin Designs 18 (2010), 123–140. © 2010 Wiley Periodicals, Inc. J Combin Designs 18: 488, 2010
THE EFFICACY OF CENTRAL BANK INTERVENTION ON THE FOREIGN EXCHANGE MARKET: UGANDA'S EXPERIENCE
Authors: Hisali Eria 
Published: September 2010

AbstractThis paper employs conditional probabilities generated from a homogenous two‐state Markov chain to obtain maximum likelihood estimates of the efficacy of central bank intervention on the foreign exchange market in Uganda. This enables us to explicitly model the fact that intervention actions usually do not target the exchange rate itself but rather its orderly movement. The results suggest that seasonal pressures are largely responsible for moving the short‐term exchange rate process between the different state spaces. Intervention reduces the probability of the exchange rate process staying in a regime characterised by sharp and disruptive tendencies. Copyright © 2010 John Wiley & Sons, Ltd.
Frequency response of multipoint chemical shift‐based spectral decomposition
Authors: Brodsky Ethan K. , Chebrolu Venkata V. , Block Walter F. , Reeder Scott B. 
Published: September 2010

AbstractPurposeTo provide a framework for characterizing the frequency response of multipoint chemical shift based species separation techniques.Materials and MethodsMultipoint chemical shift based species separation techniques acquire complex images at multiple echo times and perform maximum likelihood estimation to decompose signal from different species into separate images. In general, after a nonlinear process of estimating and demodulating the field map, these decomposition methods are linear transforms from the echo‐time domain to the chemical‐shift‐frequency domain, analogous to the discrete Fourier transform (DFT). In this work we describe a technique for finding the magnitude and phase of chemical shift decomposition for input signals over a range of frequencies using numerical and experimental modeling and examine several important cases of species separation.ResultsSimple expressions can be derived to describe the response to a wide variety of input signals. Agreement between numerical modeling and experimental results is very good.ConclusionChemical shift‐based species separation is linear, and therefore can be fully described by the magnitude and phase curves of the frequency response. The periodic nature of the frequency response has important implications for the robustness of various techniques for resolving ambiguities in field inhomogeneity. J. Magn. Reson. Imaging 2010;32:943–952. © 2010 Wiley‐Liss, Inc.
Toward local arterial input functions in dynamic contrast‐enhanced MRI
Authors: Fluckiger Jacob U. , Schabel Matthias C. , DiBella Edward V.R. 
Published: September 2010

AbstractPurposeTo present a method for estimating the local arterial input function (AIF) within a dynamic contrast‐enhanced MRI scan, based on the alternating minimization with model (AMM) method.Materials and MethodsThis method clusters a subset of data into representative curves, which are then input to the AMM algorithm to return a parameterized AIF and pharmacokinetic parameters. Computer simulations are used to investigate the accuracy with which the AMM is able to estimate the true AIF as a function of the input tissue curves.ResultsSimulations show that a power law relates uncertainty in kinetic parameters and SNR and heterogeneity of the input. Kinetic parameters calculated with the measured AIF are significantly different from those calculated with either a global (P < 0.005) or a local input function (P = 0.0). The use of local AIFs instead of measured AIFs yield mean lesion‐averaged parameter changes: Ktrans: +24% [+15%, +70%], kep: +13% [−36%, +300%]. Globally estimated input functions yield mean lesion‐averaged changes: Ktrans: +9% [−38%, +65%], kep: +13% [−100%, +400%]. The observed improvement in fit quality with local AIFs was found to be significant when additional free parameters were accounted for using the Akaike information criterion.ConclusionLocal AIFs result in significantly different kinetic parameter values. The statistically significant improvement in fit quality suggests that changes in parameter estimates using local AIFs reflect differences in underlying tissue physiology. J. Magn. Reson. Imaging 2010;32:924–934. © 2010 Wiley‐Liss, Inc.
Sp1 phosphorylation is involved in myelin basic protein gene transcription
Authors: Guo Lili , Eviatar‐Ribak Tamar , Miskimins Robin 
Published: September 2010

AbstractMyelin basic protein (MBP), which helps form compact myelin sheets, is a major protein expressed during oligodendrocyte (OL) differentiation. Myelin basic protein expression is regulated mainly at the transcriptional level. Previous studies showed that the transcription factor Sp1 can activate the MBP promoter. Data from the laboratory also indicate that Sp1 is expressed highly in both growing and differentiated cells. Because this is true, we wanted to understand how Sp1 activity is regulated such that it increases MBP gene transcription only in differentiating cells. Phosphorylation is one major way to regulate transcription factor activity. Our results show that there is more Sp1 binding to the MBP promoter in differentiating OLs. Sp1 is also more phosphorylated in differentiating OLs than in precursor cells. Using inhibitors of different pathways, we found that the protein kinase C (PKC) modulator phorbol 12‐myristate 13‐acetate (PMA) can increase Sp1 phosphorylation when the cells are treated for 1 hr and can decrease Sp1 phosphorylation with long treatment (12 hr). The increased phosphorylation of Sp1 induced by PMA in short treatments could be abolished by the extracellular signal‐regulated kinases (ERK) pathway inhibitor PD98059. This indicates that PKC phosphorylates Sp1 through the ERK pathway. Mutation of Sp1 threonines 453 and 739, which are phosphorylated by ERK, decreased MBP transcriptional activity. Furthermore, we found that PKC regulates Sp1 phosphorylation only in differentiating OLs. In conclusion, our results indicate that, in OLs, Sp1 phosphorylation can be regulated by PKC‐ERK pathways. This phosphorylation is important for MBP transcription and oligodendrocyte differentiation. © 2010 Wiley‐Liss, Inc.
Neural stem cells secrete factors that promote auditory cell proliferation via a leukemia inhibitory factor signaling pathway
Authors: Chen Hsin‐Chien , Ma Hsin‐I , Sytwu Huey‐Kang , Wang Hsing‐Won , Chen Chia‐Chi V. , Liu Shu‐Chen , Chen Chi‐Huang , Chen Hang‐Kang , Wang Chih‐Hung 
Published: September 2010

AbstractThe capacity for perpetual self‐renewal is one of the main characteristics of stem cells. Little is known about the effect of embryonic neural stem cell (NSC)‐secreted factors on auditory cell proliferation in vitro. In the present work, two auditory cell types were cultured in the presence of NSC‐secreted molecules and were evaluated in vitro. Our results demonstrated that both cell viability and cell proliferation were significantly enhanced upon treatment with NSC conditioned medium, which contains significantly elevated levels of leukemia inhibitory factor (LIF) secreted by NSCs. The NSC conditioned medium not only activated the expression of leukemia inhibitory factor receptor in House Ear Institute‐organ of Corti 1 cells but also up‐regulated the LIF downstream signal transducers and activators of transcription (STAT) 1 and STAT3. Blocking either the LIF signaling pathway with neutralizing antibodies or the downstream Janus kinase (JAK)/STAT pathway with JAK2 inhibitor AG490 resulted in a dose‐dependent inhibition of cell proliferation, suggesting that NSC‐secreted molecules promote auditory cell survival via the regulatory LIF/JAK/STAT signaling pathway. © 2010 Wiley‐Liss, Inc.