bluuebunny/crossref_metadata_2025_split huggingface dataset:
Magnesium alloys: Predicting in vivo corrosion with in vitro immersion testing
Authors: Walker Jemimah , Shadanbaz Shaylin , Kirkland Nicholas T. , Stace Edward , Woodfield Tim , Staiger Mark P. , Dias George J. 
Published: February 2012

AbstractMagnesium (Mg) and its alloys have been proposed as degradable replacements to commonly used orthopedic biomaterials such as titanium alloys and stainless steel. However, the corrosion of Mg in a physiological environment remains a difficult characteristic to accurately assess with in vitro methods. The aim of this study was to identify a simple in vitro immersion test that could provide corrosion rates similar to those observed in vivo. Pure Mg and five alloys (AZ31, Mg‐0.8Ca, Mg‐1Zn, Mg‐1Mn, Mg‐1.34Ca‐3Zn) were immersed in either Earle's balanced salt solution (EBSS), minimum essential medium (MEM), or MEM‐containing 40 g/L bovine serum albumin (MEMp) for 7, 14, or 21 days before removal and assessment of corrosion by weight loss. This in vitro data was compared to in vivo corrosion rates of the same materials implanted in a subcutaneous environment in Lewis rats for equivalent time points. The results suggested that, for the alloys investigated, the EBSS buffered with sodium bicarbonate provides a rate of degradation comparable to those observed in vivo. In contrast, the addition of components such as (4‐(2‐hydroxyethyl)‐1‐piperazineethanesulfonic acid) (HEPES), vitamins, amino acids, and albumin significantly increased corrosion rates. Based on these findings, it is proposed that with this in vitro protocol, immersion of Mg alloys in EBSS can be used as a predictor of in vivo corrosion. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012.
Asbestos exposure induces alveolar epithelial cell plasticity through MAPK/Erk signaling
Authors: Tamminen Jenni A. , Myllärniemi Marjukka , Hyytiäinen Marko , Keski‐Oja Jorma , Koli Katri 
Published: February 2012

AbstractThe inhalation of asbestos fibers is considered to be highly harmful, and lead to fibrotic and/or malignant disease. Epithelial‐to‐mesenchymal transition (EMT) is a common pathogenic mechanism in asbestos associated fibrotic (asbestosis) and malignant lung diseases. The characterization of molecular pathways contributing to EMT may provide new possibilities for prognostic and therapeutic applications. The role of asbestos as an inducer of EMT has not been previously characterized. We exposed cultured human lung epithelial cells to crocidolite asbestos and analyzed alterations in the expression of epithelial and mesenchymal marker proteins and cell morphology. Asbestos was found to induce downregulation of E‐cadherin protein levels in A549 lung carcinoma cells in 2‐dimensional (2D) and 3D cultures. Similar findings were made in primary small airway epithelial cells cultured in 3D conditions where the cells retained alveolar type II cell phenotype. A549 cells also exhibited loss of cell–cell contacts, actin reorganization and expression of α‐smooth muscle actin (α‐SMA) in 2D cultures. These phenotypic changes were not associated with increased transforming growth factor (TGF)‐β signaling activity. MAPK/Erk signaling pathway was found to mediate asbestos‐induced downregulation of E‐cadherin and alterations in cell morphology. Our results suggest that asbestos can induce epithelial plasticity, which can be interfered by blocking the MAPK/Erk kinase activity. J. Cell. Biochem. 113: 2234–2247, 2012. © 2012 Wiley Periodicals, Inc.
A DNA binding mutation in estrogen receptor‐α Leads to suppression of Wnt signaling via β‐catenin destabilization in osteoblasts
Authors: Mödder Ulrike I. , Rudnik Volha , Liu Gang , Khosla Sundeep , Monroe David G. 
Published: February 2012

AbstractEstrogen receptors (ERs) play vital roles in the function and remodeling of bone. Their cellular mechanisms can broadly be categorized into those involving direct DNA binding (classical) or indirect DNA binding (non‐classical). The generation of non‐classical ER knock‐in (ERα−/NERKI) mice provides a unique opportunity to define these pathways in bone. We previously demonstrated that ERα−/NERKI mice exhibit an osteoporotic phenotype; however, the mechanism(s) for this remain unresolved. Gene expression analyses of cortical bone from ERα−/NERKI mice revealed suppression of lymphoid enhancer factor‐1 (Lef1), a classic Wnt‐responsive transcription factor that associates with β‐catenin. Since Wnt signaling is generally considered bone anabolic, this observation leads to the hypothesis that NERKI‐induced suppression of Wnt signaling may contribute to the low bone mass phenotype. We generated ERα−/NERKI mice crossed with the Wnt‐responsive TOPGAL transgenic mouse model and observed significantly less β‐galactosidase activity in ERα−/NERKI mice, confirming suppression of Wnt activity in vivo. Adenoviral expression of the NERKI receptor using an in vitro cell system resulted in the induction of several secreted antagonists of Wnt signaling. Furthermore, expression of NERKI abrogated Wnt10b‐dependent Wnt activation using a lentiviral‐mediated reporter assay. Finally, expression of NERKI destabilized β‐catenin cellular protein levels and disrupted ER/β‐catenin interactions. Collectively, these data suggest the osteoporotic phenotype of ERα−/NERKI mice may involve the suppression of Lef1‐mediated Wnt signaling through both the stimulation of secreted Wnt inhibitors and/or disruption of normal β‐catenin function. J. Cell. Biochem. 113: 2248–2255, 2012. © 2012 Wiley Periodicals, Inc.
Inhibition of inducible nitric oxide synthase prevents lipid peroxidation in osteoarthritic chondrocytes
Authors: Bentz Mireille , Zaouter Charlotte , Shi Qin , Fahmi Hassan , Moldovan Florina , Fernandes Julio C. , Benderdour Mohamed 
Published: February 2012

AbstractNitric oxide (NO) and the lipid peroxidation (LPO) product 4‐hydroxynonenal (HNE) are considered to be key mediators of cartilage destruction in osteoarthritis (OA). NO is also known to be an important intermediary in LPO initiation through peroxynitrite formation. The aim of the present study was to assess the ability of the inducible NO synthase (iNOS) inhibitor N‐iminoethyl‐L‐lysine (L‐NIL) to prevent HNE generation via NO suppression in human OA chondrocytes and cartilage explants. Human OA chondrocytes and cartilage explants were treated with L‐NIL and thereafter with or without interleukin‐1beta (IL‐1β) or HNE at cytotoxic or non‐cytotoxic concentrations. Parameters related to oxidative stress, apoptosis, inflammation, and catabolism were investigated. L‐NIL stifled IL‐1β‐induced NO release, iNOS activity, nitrated proteins, and HNE generation in a dose‐dependent manner. It also blocked IL‐1β‐induced inactivation of the HNE‐metabolizing glutathione‐s‐transferase (GST). L‐NIL restored both HNE and GSTA4‐4 levels in OA cartilage explants. Interestingly, it also abolished IL‐1β‐evoked reactive oxygen species (ROS) generation and p47 NADPH oxidase activation. Furthermore, L‐NIL significantly attenuated cell death and markers of apoptosis elicited by exposure to a cytotoxic dose of HNE as well as the release of prostaglandin E2 and metalloproteinase‐13 induced by a non‐cytotoxic dose of HNE. Altogether, our findings support a beneficial effect of L‐NIL in OA by (i) preventing the LPO process and ROS production via NO‐dependent and/or independent mechanisms and (ii) attenuating HNE‐induced cell death and different mediators of cartilage damage. J. Cell. Biochem. 113: 2256–2267, 2012. © 2012 Wiley Periodicals, Inc.
Imaging of central nervous system viral diseases
Authors: Gupta Rakesh Kumar , Soni Neetu , Kumar Sunil , Khandelwal Niranjan 
Published: February 2012

AbstractViral infections of the central nervous system (CNS) are commonly encountered and there has been continued emergence of new neurotropic viruses which are being frequently recognized. These may present clinically as encephalitis, meningitis, encephalomyelitis, and encephalomyeloradiculitis. The clinical manifestations are usually nonspecific and diagnosis is usually based on the laboratory investigations. Imaging plays a role in its early detection and at times suggests the specific diagnosis that may help in early institution of appropriate therapy. In this review, we summarize the pathology, clinical, and imaging features of the common viral infections that affect the CNS. J. Magn. Reson. Imaging 2012;35:477‐491. © 2012 Wiley Periodicals, Inc.
Hepatobiliary MR imaging with gadolinium‐based contrast agents
Authors: Frydrychowicz Alex , Lubner Meghan G. , Brown Jeffrey J. , Merkle Elmar M. , Nagle Scott K. , Rofsky Neil M. , Reeder Scott B. 
Published: February 2012

AbstractThe advent of gadolinium‐based “hepatobiliary” contrast agents offers new opportunities for diagnostic magnetic resonance imaging (MRI) and has triggered great interest for innovative imaging approaches to the liver and bile ducts. In this review article we discuss the imaging properties of the two gadolinium‐based hepatobiliary contrast agents currently available in the U.S., gadobenate dimeglumine and gadoxetic acid, as well as important pharmacokinetic differences that affect their diagnostic performance. We review potential applications, protocol optimization strategies, as well as diagnostic pitfalls. A variety of illustrative case examples will be used to demonstrate the role of these agents in detection and characterization of liver lesions as well as for imaging the biliary system. Changes in MR protocols geared toward optimizing workflow and imaging quality are also discussed. It is our aim that the information provided in this article will facilitate the optimal utilization of these agents and will stimulate the reader's pursuit of new applications for future benefit. J. Magn. Reson. Imaging 2012;35:492‐511. © 2011 Wiley Periodicals, Inc.
DIfferential subsampling with cartesian ordering (DISCO): A high spatio‐temporal resolution dixon imaging sequence for multiphasic contrast enhanced abdominal imaging
Authors: Saranathan Manojkumar , Rettmann Dan W. , Hargreaves Brian A. , Clarke Sharon E. , Vasanawala Shreyas S. 
Published: February 2012

AbstractPurpose:To develop and evaluate a multiphasic contrast‐enhanced MRI method called DIfferential Sub‐sampling with Cartesian Ordering (DISCO) for abdominal imaging.Materials and Methods:A three‐dimensional, variable density pseudo‐random k‐space segmentation scheme was developed and combined with a Dixon‐based fat‐water separation algorithm to generate high temporal resolution images with robust fat suppression and without compromise in spatial resolution or coverage. With institutional review board approval and informed consent, 11 consecutive patients referred for abdominal MRI at 3 Tesla (T) were imaged with both DISCO and a routine clinical three‐dimensional SPGR‐Dixon (LAVA FLEX) sequence. All images were graded by two radiologists using quality of fat suppression, severity of artifacts, and overall image quality as scoring criteria. For assessment of arterial phase capture efficiency, the number of temporal phases with angiographic phase and hepatic arterial phase was recorded.Results:There were no significant differences in quality of fat suppression, artifact severity or overall image quality between DISCO and LAVA FLEX images (P > 0.05, Wilcoxon signed rank test). The angiographic and arterial phases were captured in all 11 patients scanned using the DISCO acquisition (mean number of phases were two and three, respectively).Conclusion:DISCO effectively captures the fast dynamics of abdominal pathology such as hyperenhancing hepatic lesions with a high spatio‐temporal resolution. Typically, 1.1 × 1.5 × 3 mm spatial resolution over 60 slices was achieved with a temporal resolution of 4–5 s. J. Magn. Reson. Imaging 2012;35:1484–1492. © 2012 Wiley Periodicals, Inc.
Measurement of liver T1 and T2 relaxation times in an experimental mouse model of liver fibrosis
Authors: Chow April M. , Gao Darwin S. , Fan Shu Juan , Qiao Zhongwei , Lee Frank Y. , Yang Jian , Man Kwan , Wu Ed X. 
Published: February 2012

AbstractPurpose:To characterize changes in relaxation times of liver using quantitative magnetic resonance imaging (MRI) in an experimental mouse model of liver fibrosis. Quantitative MRI is a potentially robust method to characterize liver fibrosis. However, correlation between relaxation times and fibrosis stage has been controversial.Materials and Methods:Liver fibrosis was induced in male adult C57BL/6N mice (22–25 g; n = 12) by repetitive dosing of carbon tetrachloride (CCl4). The animals were examined with a series of spin‐echo (SE) images with varying TRs and multiecho SE imaging sequence at 7 T before and 2, 4, 6, and 8 weeks after CCl4 insult. Hepatic T1 and T2 values were measured. Histology was performed with hematoxylin‐eosin staining and Masson's trichrome staining.Results:Significant increase (P < 0.001) in hepatic T1 was found at 2, 4, 6, and 8 weeks following CCl4 insult as compared with that before insult. Meanwhile, hepatic T2 at 2, 4, 6, and 8 weeks after CCl4 insult was significantly higher (P < 0.001) than that before the insult. Liver histology showed collagen deposition, edema, and infiltration of inflammatory cells in livers with CCl4 insult.Conclusion:Both longitudinal and transverse relaxation times may serve as robust markers for liver fibrosis. With the advent of single breath‐hold sequences for MR relaxometry, quantitative mapping of relaxation times can be routinely and reliably performed in abdominal organs and hence may be valuable and robust in detecting liver fibrosis at early phase and monitoring its progression. J. Magn. Reson. Imaging 2012;36:152–158. © 2012 Wiley Periodicals, Inc.
Liver fibrosis: An intravoxel incoherent motion (IVIM) study
Authors: Chow April M. , Gao Darwin S. , Fan Shu Juan , Qiao Zhongwei , Lee Frank Y. , Yang Jian , Man Kwan , Wu Ed X. 
Published: February 2012

AbstractPurpose:To characterize longitudinal changes in molecular water diffusion, blood microcirculation, and their contributions to the apparent diffusion changes using intravoxel incoherent motion (IVIM) analysis in an experimental mouse model of liver fibrosis.Materials and Methods:Liver fibrosis was induced in male adult C57BL/6N mice (22–25 g; n = 12) by repetitive dosing of carbon tetrachloride (CCl4). The respiratory‐gated diffusion‐weighted (DW) images were acquired using single‐shot spin‐echo EPI (SE‐EPI) with 8 b‐values and single diffusion gradient direction. True diffusion coefficient (Dtrue), blood pseudodiffusion coefficient (Dpseudo), and perfusion fraction (Pfraction) were measured. Diffusion tensor imaging (DTI) was also performed for comparison. Histology was performed with hematoxylin‐eosin and Masson's trichrome staining.Results:A significant decrease in Dtrue was found at 2 weeks and 4 weeks following CCl4 insult, as compared with that before insult. Similarly, Dpseudo values before injury was significantly higher than those at 2 weeks and 4 weeks after CCl4 insult. Meanwhile, Pfraction values showed no significant differences over different timepoints. For DTI, significant decrease in ADC was observed following CCl4 administration. Fractional anisotropy at 2 weeks after CCl4 insult was significantly lower than that before insult, and subsequently normalized at 4 weeks after the insult. Liver histology showed collagen deposition, the presence of intracellular fat vacuoles, and cell necrosis/apoptosis in livers with CCl4 insult.Conclusion:Both molecular water diffusion and blood microcirculation contribute to the alteration in apparent diffusion changes in liver fibrosis. Reduction in Dtrue and Dpseudo values resulted from diffusion and perfusion changes, respectively, during the progression of liver fibrosis. IVIM analysis may serve as valuable and robust tool in detecting and characterizing liver fibrosis at early stages, monitoring its progression in a noninvasive manner. J. Magn. Reson. Imaging 2012;36:159–167. © 2012 Wiley Periodicals, Inc.
Preclinical in vivo evaluation of Npe6‐mediated photodynamic therapy on normal vasculature
Authors: Moy Wesley J. , Patel Shreyas J. , Lertsakdadet Ben S. , Arora Rajan P. , Nielsen Katherine M. , Kelly Kristen M. , Choi Bernard 
Published: February 2012

AbstractBackground and ObjectiveCurrent treatments of port‐wine stain birthmarks typically involve use of a pulsed dye laser (PDL) combined with cooling of the skin. Currently, PDL therapy protocols result in varied success, as some patients experience complete blanching, while others do not. Over the past decade, we have studied the use of photodynamic therapy (PDT) as either a replacement or adjuvant treatment option to photocoagulate both small and large vasculature. The objective of the current study was to evaluate a PDT protocol that involves use of an alternate intravascular photosensitizer mono‐L‐aspartylchlorin‐e6 (NPe6) activated by an array of low‐cost light emitting diodes.Study Design/Materials and MethodsTo monitor the microvasculature, a dorsal window chamber model was installed on 22 adult male mice. The light source consisted of a custom‐built LED array that emitted 10 W at a center wavelength of 664 nm (FWHM = 20 nm). The light source was positioned at a fixed distance from the window chamber to achieve a fixed irradiance of 127 mW/cm2. A retroorbital injection of NPe6 (5 mg/kg) was performed to deliver the drug into the bloodstream. Laser irradiation was initiated immediately after injection. To monitor blood‐flow dynamics in response to PDT, we used laser speckle imaging. We employed a dose–response experimental design to evaluate the efficacy of NPe6‐mediated PDT.ResultsWe observed three general hemodynamic responses to PDT: (1) At low radiant exposures, we did not observe any persistent vascular shutdown; (2) at intermediate radiant exposures, we observed an acute decrease in blood flow followed by gradual restoration of blood flow over the 7‐day monitoring period; and (3) at high radiant exposures, we observed acute vascular shutdown that persisted during the entire 7‐day monitoring period. Dose–response analysis enabled identification of 85 J/cm2 as a characteristic radiant exposure required to achieve persistent vascular shutdown at Day 7 following PDT.ConclusionThe experimental data suggest that NPe6‐mediated PDT can achieve persistent vascular shutdown of normal microvasculature. Lasers Surg. Med. 44:158–162, 2012. © 2012 Wiley Periodicals, Inc.
Materials and Corrosion 2/2012
Authors: Schneider M. , Schroth S. , Schubert N. , Michaelis A. 
Published: February 2012

Cover: The cover shows an illustration of the experimental set up for in‐situ investigations of the anodic metal dissolution under ECM conditionsA specially designed channel flow cell is placed under an optical microscope with long distance lens. A gold disc with a small conical glass lens in the centre is embedded in the glass lid of the channel flow cell and works as cathode. The sample is placed beneath the cathode and works as anode. The gap width of the channel amounts 0.35mm. A maximum electrolyte flow rate of 12.3m/s was realized. The anodic dissolution was carried out by current controlled pulses. The test assembly allows the observation of the surface topography development of the anode as well as possible interface reactions (e.g. gas evolution). More detailed information can be found in: M. Schneider, S. Schroth, N. Schubert, A. Michaelis, In‐situ investigation of the surface‐topography during anodic dissolution of copper under near‐ECM conditions, Materials and Corrosion 2012, 63, 96.
Nano‐/Microscale Investigation of Tribological and Mechanical Properties of Epoxy/MWNT Nanocomposites
Authors: Ayatollahi Majid Reza , Doagou‐Rad Saeed , Shadlou Shahin 
Published: February 2012

AbstractThe effects of MWNT content and aspect ratio on the properties of epoxy‐based nanocomposites are investigated using nanoindentation and nanoscratch methods. The Halpin‐Tsai model for predicting the elastic modulus and hardness is modified to include the effective aspect ratio factor. The modified model predicts the experimental results more accurately. The frictional behavior is investigated and a new equation is proposed that correlates the ploughing friction with the plasticity index. The dispersion state of MWNTs and the surface features of residual grooves are investigated using scanning electron micrographs and AFM profiles. The mechanisms of improvements in the properties are also discussed.magnified image
The Singapore Mental Health Study: an overview of the methodology
Authors: Subramaniam Mythily , Vaingankar Janhavi , Heng Derrick , Kwok Kian Woon , Lim Yee Wei , Yap Mabel , Chong Siow Ann 
Published: February 2012

AbstractThe Singapore Mental Health Study (SMHS) is a population‐based, cross‐sectional, epidemiological study on the Singapore multi‐ethnic adult population. This article provides an overview of the research design and methods used which took into consideration the unique characteristics of the country and its multi‐ethnic population. A face‐to‐face household survey of Singapore residents aged 18 years and above was undertaken from 2009 to 2010. The nationally representative probability sample was derived using a disproportionate stratified sampling method. In order to increase precision for subgroup estimations the design was stratified with over‐sampling of Malays, Indians and those aged 65 years and above. Respondents were assessed using the English, Chinese (computerized) and Malay (paper and pencil based) version of the Composite International Diagnostic Interview (CIDI) 3.0 to establish lifetime and 12‐month prevalence of mental disorders, the current use of mental health services (both Western and traditional services), the treatment gaps and loss of role functioning. Copyright © 2012 John Wiley & Sons, Ltd.
The effect of leptin on maturing porcine oocytes is dependent on glucose concentration
Authors: Silva Elena , Paczkowski Melissa , Krisher Rebecca L. 
Published: February 2012

AbstractIncreased body weight is often accompanied by increased circulating levels of leptin and glucose, which alters glucose metabolism in various tissues, including perhaps the oocyte. Alteration of glucose metabolism impacts oocyte function and may contribute to the subfertility often associated with obese individuals. The objective of this study was to determine the effect of leptin (0, 10, and 100 ng/ml) on the oocyte and cumulus cells during in vitro maturation under differing glucose concentrations. We examined the effects of leptin on oocyte maturation, blastocyst development, and/or gene expression in oocytes and cumulus cells (IRS1, IGF1, PPARγ, IL6, GLUT1) in a physiological glucose (2 mM) and high glucose (50 mM) environment. We also evaluated the effect of leptin on glucose metabolism via glycolysis and the pentose phosphate pathway. In a physiological glucose environment, leptin did not have an influence on oocyte maturation, blastocyst development, or oocyte gene expression. Expression of GLUT1 in cumulus cells was downregulated with 100 ng/ml leptin treatment, but did not affect oocyte glucose metabolism. In a high glucose environment, oocyte maturation and glycolysis were decreased, but in the presence of 100 ng/ml leptin, these parameters were improved to levels similar to control. This effect is potentially mediated by an upregulation of oocyte IRS1 and a correction of cumulus cell IGF1 expression. The present study demonstrates that in a physiological glucose concentration, leptin plays a negligible role in oocyte function. However, leptin appears to modulate the deleterious impact of a high glucose environment on oocyte function. Mol. Reprod. Dev. 79: 296–307, 2012. © 2012 Wiley Periodicals, Inc.