bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differential response of nucleus pulposus intervertebral disc cells to high salt, sorbitol, and urea
Authors: Mavrogonatou Eleni , Kletsas Dimitris 
Published: May 2011

AbstractNucleus pulposus intervertebral disc cells are routinely confronted with high osmolality in their microenvironment and respond to this stress in vitro by regulating cell cycle progression and by activating a DNA repair machinery in order to counteract its genotoxic effect. In the present study, we attempted to identify the origin of this osmo‐regulatory response, by using an ionic NaCl/KCl solution, the compatible osmolyte sorbitol, and the readily permeant urea. High salt and sorbitol were found to activate similar molecular pathways, including the p38 MAPK and the p53‐p21WAF1‐pRb axis, that were not stimulated by high urea. On the other hand, only high urea led to the phosphorylation of ERKs and JNKs. Furthermore, salt‐ and sorbitol‐treated cells were able to phosphorylate histone H2A.X on Ser139, in contrast to cells exposed to urea, indicating a common mechanism for DNA repair, which was achieved by a p53‐dependent activation of the G1 checkpoint by both solutes. DNA repair, as directly measured by a host cell reactivation assay, occurred under conditions of hyperosmolar salt and sorbitol, although to a lesser extent in sorbitol‐treated cells than in cells exposed to high salinity. Taken as a whole, our findings suggest that the hyperosmolality‐provoked DNA damage and the responses of nucleus pulposus cells induced by this genotoxic stress most probably originate from cell volume alterations mediated by hypertonicity and not from increased intracellular ionic concentration. J. Cell. Physiol. 227: 1179–1187, 2012. © 2011 Wiley Periodicals, Inc.
Sorafenib sensitizes hepatocellular carcinoma cells to physiological apoptotic stimuli
Authors: Fernando Joan , Sancho Patricia , Fernández‐Rodriguez Conrado M. , Lledó José L. , Caja Laia , Campbell Jean S. , Fausto Nelson , Fabregat Isabel 
Published: May 2011

AbstractSorafenib increases survival rate of patients with advanced hepatocellular carcinoma (HCC). The mechanism underlying this effect is not completely understood. In this work we have analyzed the effects of sorafenib on autocrine proliferation and survival of different human HCC cell lines. Our results indicate that sorafenib in vitro counteracts autocrine growth of different tumor cells (Hep3B, HepG2, PLC‐PRF‐5, SK‐Hep1). Arrest in S/G2/M cell cycle phases were observed coincident with cyclin D1 down‐regulation. However, sorafenib's main anti‐tumor activity seems to occur through cell death induction which correlated with caspase activation, increase in the percentage of hypodiploid cells, activation of BAX and BAK and cytochrome c release from mitochondria to cytosol. In addition, we observed a rise in mRNA and protein levels of the pro‐apoptotic “BH3‐domain only” PUMA and BIM, as well as decreased protein levels of the anti‐apoptotic MCL1 and survivin. PUMA targeting knock‐down, by using specific siRNAs, inhibited sorafenib‐induced apoptotic features. Moreover, we obtained evidence suggesting that sorafenib also sensitizes HCC cells to the apoptotic activity of transforming growth factor‐β (TGF‐β) through the intrinsic pathway and to tumor necrosis factor‐α (TNF) through the extrinsic pathway. Interestingly, sensitization to sorafenib‐induced apoptosis is characteristic of liver tumor cells, since untransformed hepatocytes did not respond to sorafenib inducing apoptosis, either alone or in combination with TGF‐β or TNF. Indeed, sorafenib effectiveness in delaying HCC late progression might be partly related to a selectively sensitization of HCC cells to apoptosis by disrupting autocrine signals that protect them from adverse conditions and pro‐apoptotic physiological cytokines. J. Cell. Physiol. 227: 1319–1325, 2012. © 2011 Wiley Periodicals, Inc.
Targeting of substance P induces cancer cell death and decreases the steady state of EGFR and Her2
Authors: Mayordomo Cristina , García‐Recio Susana , Ametller Elisabet , Fernández‐Nogueira Patricia , Pastor‐Arroyo Eva María , Vinyals Laia , Casas Ignasi , Gascón Pedro , Almendro Vanessa 
Published: May 2011

AbstractNK1 is a tachykinin receptor highly relevant to tumorigenesis and metastasis development in breast cancer and other carcinomas. Despite the substantial efforts done to develop potent NK1 receptor antagonists, none of these antagonists had shown good antitumor activity in clinical trials. Now, we have tested the effect of inhibition of the neuropeptide Substance P (SP), a NK1 ligand, as a potential therapeutic approach in cancer. We found that the inhibition of SP with antibodies strongly inhibit cell growth and induce apoptosis in breast, colon, and prostate cancer cell lines. These effects were accompained by a decrease in the mitogen‐activated kinase singaling pathway. Interestingly, in some cell lines SP abrogation decreased the steady state of Her2 and EGFR, suggesting that SP‐mediated signaling is important for the basal activity of these ErbB receptors. In consequence, we observed a blockade of the cell cycle progression and the inhibition of several cell cycle‐related proteins including mTOR. SP inhibition also induced cell death in cell lines resistant to Lapatinib and Trastuzumab that have increased levels of active Her2, suggesting that this therapeutic approach could be also effective for those cancers resistant to current anti‐ErbB therapies. Thus, we propose a new therapeutic strategy for those cancers that express NK1 receptor and/or other tachykinin receptors, based in the immuno‐blockade of the neuropeptide SP. J. Cell. Physiol. 227: 1358–1366, 2012. © 2011 Wiley Periodicals, Inc.
Effect of indigenous mycorrhizal colonization on phosphorus‐acquisition efficiency in soybean and sunflower
Authors: Cecilia Fernández Mariana , Hernán Gutiérrez Boem Flavio , Rubio Gerardo 
Published: May 2011

AbstractDespite a general consent about the beneficial contribution of arbuscular mycorrhizal fungi (AMF) on natural ecosystems, there is an intense debate about their role in agricultural systems. In this work, soybean (Glycine max L.) and sunflower (Helianthus annuus L.) field plots with different P availabilities were sampled across the Pampean Region of Argentina (> 150 samples from Mollisols) to characterize the relationship between available soil P and indigenous mycorrhizal colonization. A subsequent pot experiment with soybean and sunflower was carried out to evaluate the effect of P supply (0, 12, and 52 mg P kg–1) and AMF inoculation on AMF colonization and crop responsiveness to P in a Mollisol. Both crops showed high AMF colonization in the field (average: 55% for soybean and 44% for sunflower). While mycorrhizal colonization in soybean was significantly and negatively related to available soil P, no such trends were apparent in sunflower. Also, total biomass was 3.5 and 2.0 times higher in mycorrhizal than in nonmycorrhizal pot‐grown soybean under low‐ and medium‐P conditions, respectively. Sunflower, on the other hand, did not benefit from AMF symbiosis under medium and high P supply. While mycorrhization stimulated P‐uptake efficiency in soybean, the generally high P efficiency in sunflower was not associated with AMF symbiosis.
Effects of residue location on soil organic matter turnover: results from an incubation experiment with 15N‐maize
Authors: Jacobs Anna , Helfrich Mirjam , Dyckmans Jens , Rauber Rolf , Ludwig Bernard 
Published: May 2011

AbstractDifferences in the mechanisms of storage and decomposition of organic matter (OM) between minimum tillage (MT) and conventional tillage (CT) are generally attributed to differences in the physical impact through tillage, but less is known about the effects of residue location. We conducted an incubation experiment at a water content of 60% of the maximum water‐holding capacity and 15°C with soils from CT (0–25 cm tillage depth) and MT fields (0–5 cm tillage depth) with 15N‐labeled maize straw incorporated to different depths (CT simulations: 0–15 cm; MT simulations: 0–5 cm) for 28 d in order to determine the effects of the tillage simulation on (1) mineralization of recently added residues, (2) the dynamics of macroaggregate formation and physical protection of OM, and (3) the partitioning of maize‐derived C and N within soil OM fractions. The MT simulations showed lower relative C losses, and the amount of maize‐C mineralized after 28 d of incubation was slightly but significantly lower in the MT simulations with maize added (MTmaize) than in the respective CT (CTmaize) simulations. The formation of new water‐stable macroaggregates occurred during the phase of the highest microbial activity, with a maximum peak 8 d after the start of incubation. The newly formed macroaggregates were an important location for the short‐term stabilization of C and N with a higher importance for MTmaize than for CTmaize simulations. In conclusion, our results suggest that a higher amount of OM in MT surface soils compared with CT surface soils may not only result from decreased macroaggregate destruction under reduced tillage but also from a higher efficiency of C retention due to a more concentrated residue input.
Generic, Anthracene‐Based Hydrogel Crosslinkers for Photo‐controllable Drug Delivery
Authors: Wells Laura A. , Brook Michael A. , Sheardown Heather 
Published: May 2011

AbstractLight‐responsive polymers with controllable, reversible crosslink mechanisms have the potential to create unique biomaterials with stimulus‐controlled swelling, degradation and diffusion properties useful in tissue engineering and drug delivery applications. Generic photodimerizing polyethylene glycol–anthracene macromolecules that may be grafted to various polymers to effectively control their crosslinking via a photodimerization mechanism have been developed. These generic crosslinkers were shown to effectively introduce photoresponsive properties into hyaluronate and alginate as model hydrophilic polymers. In vitro testing using human corneal epithelial cells was used to demonstrate cytocompatibility of the resulting photogels. The effective crosslinking density of the photogels could be increased resulting in a decrease in the release rate of small and large molecules from the photogels following exposure to 365 nm light. This tuneable crosslinking has the potential to manipulate the delivery rates of therapeutics resulting in control over treatment profiles and may lend itself to various applications, which may benefit from light induced changes in crosslinking.magnified image
Local specific absorption rate control for parallel transmission by virtual observation points
Authors: Eichfelder Gabriele , Gebhardt Matthias 
Published: May 2011

AbstractThe supervision of local specific absorption rate (SAR) in parallel transmission applications in MRI is crucial. One existing approach is to use electromagnetic simulations including human anatomical models and to precalculate the electric field distributions of each individual channel. These can be superposed later with respect to certain combined excitations under investigation, and the local SAR distribution can be evaluated. Local SAR maxima can be obtained by exhaustive search over all investigated subvolumes of the body model. Practical challenges arise for the adequate handling and comparing of precalculated field distributions as long as the expected combined radiofrequency excitations are still undetermined. Worst‐case approximations for local SAR lead to significant radiofrequency pulse performance limitations. Optimizing local SAR in radiofrequency pulse design using constraints for each subvolume is impractical. A method is proposed to significantly reduce the complexity without restriction to particular radiofrequency excitations. By constructing several matrices, it becomes sufficient to consider only these so‐called Virtual Observation Points for an adequate, conservative estimation of the maximum local SAR. The applied techniques involve concepts of vector optimization as well as semidefinite programming. Magn Reson Med, 2011. © 2011 Wiley Periodicals, Inc.
Robust fat suppression at 3T in high‐resolution diffusion‐weighted single‐shot echo‐planar imaging of human brain
Authors: Sarlls Joelle E. , Pierpaoli Carlo , Talagala S. Lalith , Luh Wen‐Ming 
Published: May 2011

AbstractSingle‐shot echo‐planar imaging is the most common acquisition technique for whole‐brain diffusion tensor imaging (DTI) studies in vivo. Higher field MRI systems are readily available and advantageous for acquiring DTI due to increased signal. One of the practical issues for DTI with single‐shot echo‐planar imaging at high‐field is incomplete fat suppression resulting in a chemically shifted fat artifact within the brain image. Unsuppressed fat is especially detrimental in DTI because the diffusion coefficient of fat is two orders of magnitude lower than that of parenchyma, producing brighter appearing fat artifacts with greater diffusion weighting. In this work, several fat suppression techniques were tested alone and in combination with the goal of finding a method that provides robust fat suppression and can be used in high‐resolution single‐shot echo‐planar imaging DTI studies. Combination of chemical shift saturation with slice‐select gradient reversal within a dual‐spin‐echo diffusion preparation period was found to provide robust fat suppression at 3 T. Magn Reson Med, 2011. © 2011 Wiley Periodicals, Inc.
Determination of regional variations and reproducibility in in vivo 1H NMR spectroscopy of the rat brain at 16.4 T
Authors: Hong Sung‐Tak , Balla David Z. , Pohmann Rolf 
Published: May 2011

AbstractIn vivo 1H NMR spectroscopy was used to obtain the neurochemical profile in the posterior parts of the brain, the cerebellum and the medulla oblongata in comparison to the hippocampus and the thalamus. Using small voxel sizes between 16 and 32 μl to avoid partial volume effects, most metabolites demonstrated significant regional differences except acetate, γ‐aminobutyric acid, and phosphorylcholine. Noticeable regional differences in metabolite concentrations were the significant increase of total creatine in the cerebellum and the substantial decrease of taurine in thalamus and medulla oblongata. In particular, the glycine concentration in the medulla oblongata was determined to be 4.37 ± 0.68 μmol/g (Cramér‐Rao lower bounds 7%) and thus significantly higher than in the other regions, consistent with findings reported in both in vivo 1H NMR spectroscopy and in vitro biochemical assays. Intraindividual reproducibility and interindividual variability were investigated by acquiring spectra from the thalamus of the same rats in two sessions. No prominent influence on measurement session was observed in metabolite concentrations with coefficients of variations being below 20% in 16 metabolites. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.
Improving the Delivery of Global Tobacco Control
Authors: Bitton Asaf , Green Carol , Colbert James 
Published: May 2011

AbstractTobacco control must remain a critical global health priority given the growing burden of tobacco‐induced disease in the developing world. Insights from the emerging field of global health delivery suggest that tobacco control could be improved through a systematic, granular analysis of the processes through which it is promoted, implemented, and combated. Using this framework, a critical bottleneck to the delivery of proven health promotion emerges in the role that the tobacco industry plays in promoting tobacco use and blocking effective tobacco‐control policies. This “corporate bottleneck” can also be understood as a root cause of massive disease and suffering upon vulnerable populations worldwide, for the goal of maximizing corporate profit. Naming, understanding, and responding to this corporate bottleneck is crucial to the success of tobacco‐control policies. Three case studies of tobacco‐control policy–South Africa, the Framework Convention on Tobacco Control, and Uruguay–are presented to explore and understand the implications of this analysis. Mt Sinai J Med 78:382–393, 2011. © 2011 Mount Sinai School of Medicine
Role of Students in Global Health Delivery
Authors: Finch Thomas H. , Chae Sae‐Rom , Shafaee Maryam N. , Siegel Karen R. , Ali Mohammed K. , Tomei Rachelle , Panjabi Rajesh , Kishore Sandeep P. 
Published: May 2011

AbstractWhat role do students have in global health activities? On one hand, students have much to offer, including innovative ideas, fresh knowledge and perspective, and inspiring energy. At the same time, students lack technical credentials and may drain resources from host communities. Here, we examine the dynamic, contemporary roles of students in global health activities, including health delivery. We focus on 3 themes that guide engagement: (1) fostering an enabling policy environment (eg, toward greater health equity); (2) understanding and working within the local context and governments' needs; and (3) leading bidirectional partnerships. We next study the implications of short‐term exposure and long‐term engagement programs. We conclude with 4 recommendations on how to better equip students to engage in the next frontier of global health education and future action. Mt Sinai J Med 78:373–381, 2011. © 2011 Mount Sinai School of Medicine
New Academic Partnerships in Global Health: Innovations at Mount Sinai School of Medicine
Authors: Landrigan Philip J. , Ripp Jonathan , Murphy Ramon J. C. , Claudio Luz , Jao Jennifer , Hexom Braden , Bloom Harrison G. , Shirazian Taraneh , Elahi Ebby , Koplan Jeffrey P. 
Published: May 2011

AbstractGlobal health has become an increasingly important focus of education, research, and clinical service in North American universities and academic health centers. Today there are at least 49 academically based global health programs in the United States and Canada, as compared with only one in 1999. A new academic society, the Consortium of Universities for Global Health, was established in 2008 and has grown significantly. This sharp expansion reflects convergence of 3 factors: (1) rapidly growing student and faculty interest in global health; (2) growing realization–powerfully catalyzed by the acquired immune deficiency syndrome epidemic, the emergence of other new infections, climate change, and globalization–that health problems are interconnected, cross national borders, and are global in nature; and (3) rapid expansion in resources for global health. This article examines the evolution of the concept of global health and describes the driving forces that have accelerated interest in the field. It traces the development of global health programs in academic health centers in the United States. It presents a blueprint for a new school‐wide global health program at Mount Sinai School of Medicine. The mission of that program, Mount Sinai Global Health, is to enhance global health as an academic field of study within the Mount Sinai community and to improve the health of people around the world. Mount Sinai Global Health is uniting and building synergies among strong, existing global health programs within Mount Sinai; it is training the next generation of physicians and health scientists to be leaders in global health; it is making novel discoveries that translate into blueprints for improving health worldwide; and it builds on Mount Sinai's long and proud tradition of providing medical and surgical care in places where need is great and resources few. Mt Sinai J Med 78:471–483, 2011. © 2011 Mount Sinai School of Medicine
Cervical Cancer Screening in Low‐ and Middle‐Income Countries
Authors: Ditzian Lauren R. , David‐West Gizelka , Maza Mauricio , Hartmann Beatrix , Shirazian Taraneh , Cremer Miriam 
Published: May 2011

AbstractCervical cancer is a leading cause of death among women in the developing world. Conventional cytology‐based cervical cancer screening programs have been largely ineffectual at reducing the cervical cancer burden in low‐resource settings. In response, alternative strategies have been tested, such as visual inspection with acetic acid (VIA) screening and human papillomavirus (HPV) DNA‐based testing. This manuscript reviews literature addressing the programmatic approaches to implementing cervical cancer screening programs in low‐resource settings, highlighting the challenges, barriers, and successes related to the use of cytology, VIA, and HPV‐DNA based screening programs. Mt Sinai J Med 78:319–326, 2011 © 2011 Mount Sinai School of Medicine
Effects of mechanical force on crystalline structure of electrospun poly(1‐butene) membranes
Authors: Lee Yujin , Lee Jieun , Kimura Disuke , Kim Byoung‐Suhk , Koh Joonseok , Kim Ick‐Soo 
Published: May 2011

AbstractFibrous poly(1‐butene) membranes were prepared from solutions using mixed solvents via electrospinning. The electrospun fibrous poly(1‐butene) membranes were stretched at elongations of 8, 16 and 24%, respectively. Scanning electron microscopy and stress–strain analysis showed that the deformation was elastic at an elongation of 8%, while plastic deformation occurred above 16%. The crystalline transformation induced by mechanical stretching was investigated using wide‐angle X‐ray diffraction. The poly(1‐butene) membrane stretched at 24% exhibited decreased diffraction intensity at 2θ = 11.8° and 18.3°, corresponding to the (200) and (213) crystalline reflections, indicating that crystalline transformation from metastable form II to either stable form I or I′ occurred due to mechanical stretching. Copyright © 2011 Society of Chemical Industry
Polymer electrolyte membrane based on poly(ether sulfone) containing binaphthyl units with pendant perfluoroalkyl sulfonic acids
Authors: Nakagawa Taijiro , Nakabayashi Kazuhiro , Higashihara Tomoya , Ueda Mitsuru 
Published: May 2011

AbstractA novel poly(ether sulfone) containing binaphthyl units with pendant perfluoroalkyl sulfonic acids (BNSH‐PSA) was developed for a polymer electrolyte membrane (PEM). The BNSH‐PSA was prepared by the aromatic nucleophilic substitution reaction of 1,1′‐binaphthyl‐4,4′‐diol and 4,4′‐dichlorodiphenylsulfone, followed by the bromination with bromine, and then the Ullman coupling reaction with potassium 1,1,2,2,‐tetrafluoro‐2‐(1,1,2,2‐tetrafluoro‐2‐iodoethoxy) ethanesulfonate (PSA‐K). The ion exchange capacity (IEC) of BNSH‐PSA was estimated to be 1.91 mequiv/g, which corresponded to full conversion to the perfluroalkyl sulfonic acids. The BNSH‐PSA membrane prepared by solution casting showed high oxidative and dimensional stability. High proton conductivity comparable to the Nafion 117 membrane was accomplished in the range of 30–95% relative humidity (RH) due to the high acidity of the perfluoroalkyl sulfonic acids. Furthermore, atomic force microscopic observation supported the formation of the phase‐separated structure that the hydrophilic domains were well dispersed and connected to each other. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Equilibrium statistics of weakly slip‐linked Gaussian polymer chains
Authors: Uneyama Takashi , Horio Kazushi 
Published: May 2011

AbstractWe calculate the free energy and the pressure of a weakly slip‐linked Gaussian polymer chains. We show that the equilibrium statistics of a slip‐linked system is different from one of the corresponding ideal chain system without any constraints by slip‐links. It is shown that the pressure of a slip‐linked system decreases compared with the ideal system, which implies that slip‐linked chains spontaneously form aggregated cluster‐like compact structures. These are qualitatively consistent with previous theoretical analyses or multichain simulations. We also show that repulsive potentials between chains, which have been phenomenologically utilized in simulations, can cancel the artificial pressure decrease. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011