bluuebunny/crossref_metadata_2025 huggingface dataset:
Meat and fish consumption and risk of pancreatic cancer: Results from the European Prospective Investigation into Cancer and Nutrition
Authors: Rohrmann Sabine , Linseisen Jakob , Nöthlings Ute , Overvad Kim , Egeberg Rikke , Tjønneland Anne , Boutron‐Ruault Marie Christine , Clavel‐Chapelon Françoise , Cottet Vanessa , Pala Valeria , Tumino Rosario , Palli Domenico , Panico Salvatore , Vineis Paolo , Boeing Heiner , Pischon Tobias , Grote Verena , Teucher Birigit , Khaw Kay‐Tee , Wareham Nicholas J. , Crowe Francesca L. , Goufa Ioulia , Orfanos Philippos , Trichopoulou Antonia , Jeurnink Suzanne M. , Siersema Peter D. , Peeters Petra H.M. , Brustad Magritt , Engeset Dagrun , Skeie Guri , Duell Eric J. , Amiano Pilar , Barricarte Aurelio , Molina‐Montes Esther , Rodríguez Laudina , Tormo María‐José , Sund Malin , Ye Weimin , Lindkvist Björn , Johansen Dorthe , Ferrari Pietro , Jenab Mazda , Slimani Nadia , Ward Heather , Riboli Elio , Norat Teresa , Bueno‐de‐Mesquita H. Bas
Published: May 2012

Pancreatic cancer is the fourth most common cause of cancer death worldwide with large geographical variation, which implies the contribution of diet and lifestyle in its etiology. We examined the association of meat and fish consumption with risk of pancreatic cancer in the European Prospective Investigation into Cancer and Nutrition (EPIC). A total of 477,202 EPIC participants from 10 European countries recruited between 1992 and 2000 were included in our analysis. Until 2008, 865 nonendocrine pancreatic cancer cases have been observed. Calibrated relative risks (RRs) and 95% confidence intervals (CIs) were computed using multivariable‐adjusted Cox hazard regression models. The consumption of red meat (RR per 50 g increase per day = 1.03, 95% CI = 0.93–1.14) and processed meat (RR per 50 g increase per day = 0.93, 95% CI = 0.71–1.23) were not associated with an increased pancreatic cancer risk. Poultry consumption tended to be associated with an increased pancreatic cancer risk (RR per 50 g increase per day = 1.72, 95% CI = 1.04–2.84); however, there was no association with fish consumption (RR per 50 g increase per day = 1.22, 95% CI = 0.92–1.62). Our results do not support the conclusion of the World Cancer Research Fund that red or processed meat consumption may possibly increase the risk of pancreatic cancer. The positive association of poultry consumption with pancreatic cancer might be a chance finding as it contradicts most previous findings.
The effects of transcranial direct current stimulation with visual illusion in neuropathic pain due to spinal cord injury: An evoked potentials and quantitative thermal testing study
Authors: Kumru H. , Soler D. , Vidal J. , Navarro X. , Tormos J.M. , Pascual‐Leone A. , Valls‐Sole J.
Published: May 2012

Background

Neuropathic pain (NP) is common in spinal cord injury (SCI) patients. One of its manifestations is a lowering of pain perception threshold in quantitative thermal testing (QTT) in dermatomes rostral to the injury level. Transcranial direct current stimulation (tDCS) combined with visual illusion (VI) improves pain in SCI patients. We studied whether pain relief with tDCS + VI intervention is accompanied by a change in contact heat‐ evoked potentials (CHEPs) or in QTT.

Methods

We examined 18 patients with SCI and NP before and after 2 weeks of daily tDCS + VI intervention. Twenty SCI patients without NP and 14 healthy subjects served as controls. We assessed NP intensity using a numerical rating scale (NRS) and determined heat and pain thresholds with thermal probes. CHEPs were recorded to stimuli applied at C4 level, and subjects rated their perception of evoked pain using NRS during CHEPs.

Results

Thirteen patients reported a mean decrease of 50% in the NRS for NP after tDCS + VI. Evoked pain perception was significantly higher than in the other two groups, and reduced significantly together with CHEPs amplitude after tDCS + VI with respect to baseline. Pain perception threshold was significantly lower than in the other two groups before tDCS + VI intervention, and increased significantly afterwards.

Conclusion

Two weeks of tDCS + VI induced significant changes in CHEPs, evoked pain and heat pain threshold in SCI patients with NP. These neurophysiological tests might be objective biomarkers of treatment effects for NP in patients with SCI.
EFFICIENT AGGREGATION OF PANEL QUALITATIVE SURVEY DATA
Authors: Mitchell James , Smith Richard J. , Weale Martin R.
Published: May 2012

Qualitative business survey data are used widely to provide indicators of economic activity ahead of the publication of official data. Traditional indicators exploit only aggregate survey information, namely the proportions of respondents who report ‘up’ and ‘down’. This paper examines disaggregate or firm‐level survey responses. It considers how the responses of the individual firms should be quantified and combined if the aim is to produce an early indication of official output data. Having linked firms' categorical responses to official data using ordered discrete‐choice models, the paper proposes a statistically efficient means of combining the disparate estimates of aggregate output growth which can be constructed from the responses of individual firms. An application to firm‐level survey data from the Confederation of British Industry shows that the proposed indicator can provide early estimates of output growth more accurately than traditional indicators. Copyright © 2012 John Wiley & Sons, Ltd.
MULTIVARIATE VOLATILITY MODELING OF ELECTRICITY FUTURES
Authors: Bauwens Luc , Hafner Christian M. , Pierret Diane
Published: May 2012

We model the dynamic volatility and correlation structure of electricity futures of the European Energy Exchange index. We use a new multiplicative dynamic conditional correlation (mDCC) model to separate long‐run from short‐run components. We allow for smooth changes in the unconditional volatilities and correlations through a multiplicative component that we estimate nonparametrically. For the short‐run dynamics, we use a GJR‐GARCH model for the conditional variances and augmented DCC models for the conditional correlations. We also introduce exogenous variables to account for congestion and delivery date effects in short‐term conditional variances. We find different correlation dynamics for long‐ and short‐term contracts and the new model achieves higher forecasting performance compared \to a standard DCC model. Copyright © 2012 John Wiley & Sons, Ltd.
NON‐LINEAR DSGE MODELS AND THE CENTRAL DIFFERENCE KALMAN FILTER
Authors: Andreasen Martin M.
Published: May 2012

This paper introduces a quasi maximum likelihood approach based on the central difference Kalman filter to estimate non‐linear dynamic stochastic general equilibrium (DSGE) models with potentially non‐Gaussian shocks. We argue that this estimator can be expected to be consistent and asymptotically normal for DSGE models solved up to third order. These properties are verified in a Monte Carlo study for a DSGE model solved to second and third order with structural shocks that are Gaussian, Laplace distributed, or display stochastic volatility. Copyright © 2012 John Wiley & Sons, Ltd.
Transient alterations of the blood–brain barrier tight junction and receptor potential channel gene expression by chlorpyrifos
Authors: Li Wen , Ehrich Marion
Published: May 2012

The blood–brain barrier (BBB) is formed by specialized endothelial cells lining capillaries in the central nervous system (CNS). We previously demonstrated that exposure to very low concentrations of the organophosphorus insecticide chlorpyrifos (CPF) decreased electrical resistance across the BBB in vitro, indicating a loss of BBB integrity. The present study examined the transient effects of CPF on expression of genes contributing to tight junctions of the BBB. Rat brain endothelial cells (RBE4) were co‐cultured with rat astrocytes on membrane inserts to form an in vitro BBB. The RBE4 cells in the BBB were then exposed to CPF for 2, 4 and 12 h. Total RNA was extracted from RBE4 cells and quantitative real‐time PCR (qRT‐PCR) was used to quantify levels of gene expression of tight junction proteins claudin5, scaffold proteins zona occludens (ZO1) and transient receptor potential (canonical) channels (TRPC4). Gene expression decreased 2 h after exposure to CPF, especially TRPC4, but the effects were reversed 12 h later. CPF exposure for only 15 min caused less effect than longer exposures, with TRPC4 gene expression above the control at 4 h. These results suggest that altering gene expression for claudin5, TRPC4 and ZO1 by CPF may directly contribute to BBB disruption, and that the alteration is reversible upon removal of CPF. Copyright © 2012 John Wiley & Sons, Ltd.
Modulation of aryl hydrocarbon receptor‐regulated genes by acute administration of ammonium metavanadate in kidney, lung and heart of C57BL/6 mice
Authors: Abdelhamid Ghada , Amara Issa E.A. , Anwar‐Mohamed Anwar , El‐Kadi Ayman O.S.
Published: May 2012

We recently reported that vanadium (V5+) was able to decrease the 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin (TCDD)‐mediated induction of Cyp1a1 and Nqo1 at mRNA, protein and catalytic activity levels in mouse hepatoma Hepa 1c1c7 and human hepatoma HepG2 cells. However, little is known regarding the in vivo effects. Thus, the objective of this study was to investigate whether similar effects would occur at the in vivo level. Therefore, we examined the effect of exposure to V5+ (5 mg kg−1) with or without TCDD (15 µg kg−1) on the AhR‐regulated genes in kidney, lung and heart of C57BL/6 J mice. Our results demonstrated that V5+ alone significantly decreased Cyp1b1 protein and catalytic activity levels in kidney at 24 h. Moreover, it significantly potentiated Nqo1 and Gsta1 gene expression in the heart, and only Gsta1 gene expression in the lung. Upon co‐exposure, we found that V5+significantly inhibited the TCDD‐mediated induction of Cyp1a1, Cyp1a2 and Cyp1b1 mRNA, protein and catalytic activity levels in the kidney at 24 h. On the other hand, V5+ significantly potentiated the TCDD‐mediated induction of Nqo1 and Gsta1 protein and activity levels in the kidney. Cyp1a1, Cyp1b1, Nqo1 mRNA, protein and catalytic activity levels in the lung were significantly potentiated at 6 h. Interestingly, all tested genes in the heart were significantly decreased at 6 h with the exception of Gsta1 mRNA. The present study demonstrates that V5+ modulates TCDD‐induced AhR‐regulated genes. Furthermore, the effect on one of these enzymes could not be generalized to other enzymes even if it was in the same organ. Copyright © 2012 John Wiley & Sons, Ltd.
Nanoparticulate silver increases uric acid and allantoin excretion in rats, as identified by metabolomics
Authors: Hadrup Niels , Lam Henrik R. , Loeschner Katrin , Mortensen Alicja , Larsen Erik H. , Frandsen Henrik
Published: May 2012

Metabolomic investigation of rat urine was employed to identify mammalian metabolites affected by ionic or nanoparticulate silver. Female and male Wistar rats were administered silver nanoparticles (2.25, 4.5 or 9.0 mg kg−1 body weight per day) or ionic silver (silver acetate, 9.0 mg silver kg−1 bw per day) by oral gavage for 28 days. On day 18, urine was collected for 24 h and subjected to metabolomics with high performance liquid chromatography–quadropole time‐of‐flight mass spectrometry (HPLC‐QTOF‐MS)‐based separation and detection. Principal component analysis was subsequently applied to the data. Metabolomic differences in urine composition were found in female rats but not in male rats. Several metabolites were identified by the use of elemental composition calculated from the exact mass combined with searches in the Human Metabolome Database.The metabolite identities were eventually verified by co‐chromatography with authentic standards. Differences were found in uric acid and its degradation product, allantoin. Administration of nanoparticulate silver increased both metabolites, whereas ionic silver only increased allantoin. In conclusion, metabolomic investigation of rat urine showed that increased levels of uric acid and allantoin were associated with exposure to nanoparticulate silver. Copyright © 2012 John Wiley & Sons, Ltd.
Effect of Prolonged Storage of Seminal Plasma on Levels of Calcium and Magnesium
Authors: Valsa J. , Skandhan K. P. , Sumangala B. , Sahab Khan P. , Amith S.
Published: May 2012

Background

In laboratories, the semen or seminal plasma samples are stored before estimation of different elements without knowing the adverse effect of storing. The present study shows the levels of Ca++ and Mg++ in the seminal plasma before and after the storage.

Methods

Atomic absorption spectrophotometry (AAS) was used for estimating calcium and magnesium levels in the seminal plasma. Samples were stored for one year in different containers such as polyethylene, plastic, ordinary glass, and borosil glass. Calcium and magnesium levels were estimated after this period by AAS. The total area in contact with containers was considered in the final calculation.

Results

After 1‐year storage, the levels of calcium and magnesium had changed. The most suitable container for storage of calcium was ordinary glass (P > 0.05) whereas ordinary glass (P > 0.05), polyethylene (P > 0.05), and borosil glass (P > 0.05) are the most suitable for magnesium.

Conclusion

In any elemental study, the most suitable containers are recommended for storage of the semen/seminal plasma samples. J. Clin. Lab. Anal. 26:315‐316, 2012. © 2012 Wiley Periodicals, Inc.
THE BIAS OF “MUSIC‐INFECTED CONSCIOUSNESS”: THE AESTHETICS OF LISTENING IN THE LABORATORY AND ON THE CITY STREETS OF FIN‐DE‐SIÈCLE BERLIN AND VIENNA
Authors: HUI ALEXANDRA E.
Published: May 2012

Shifts in the psychophysical study of sound sensation reinforced the changing status of musical expertise in the nineteenth century. The Carl Stumpf‐Wilhelm Wundt debate about tone‐differentiation experimentation narrowed the conception of hearing. For Stumpf, “music consciousness” (Musikbewusstsein) granted the experimental subjects exceptional insight into sound sensation. This belief reflected a cultural reevaluation of listening, exemplified in music critic Eduard Hanslick decrying the scourge of the city: the piano playing of the neighbors. Stumpf and Hanslick's defenses of subjective musical expertise both inside the laboratory and on the city streets reveal the increasingly divergent conceptions of hearing and listening.
Cross‐lagged associations between perceived external employability, job insecurity, and exhaustion: Testing gain and loss spirals according to the Conservation of Resources Theory
Authors: De Cuyper Nele , Mäkikangas Anne , Kinnunen Ulla , Mauno Saija , Witte Hans De
Published: May 2012

This study investigates perceived external employability (PEE) as a personal resource in relation to job insecurity and exhaustion. We advance the idea that PEE may reduce feelings of job insecurity and, through felt job insecurity, also exhaustion. That is, we probe the paths from PEE to job insecurity and from job insecurity to exhaustion. We furthermore account for possible reversed causality, so that exhaustion → felt job insecurity and felt job insecurity → PEE. This aligns with insights from the Conservation of Resources Theory, which is built on the assumption of resource caravans passageways and associated gain and loss spirals. We based the results on a sample of 1314 workers from two Finnish universities. Respondents participated twice in the study with a time lag of one year. We found that PEE related negatively to felt job insecurity and vice versa. Similarly, there was a reciprocal positive relationship between felt job insecurity and exhaustion. We conclude that PEE may prevent feelings of insecurity and, through reduced job insecurity, also exhaustion. Copyright © 2012 John Wiley & Sons, Ltd.
Doubly Biomimetic Catecholic Phosphorylcholine Copolymer: A Platform Strategy for Fabricating Antifouling Surfaces
Authors: Gong Yong‐Kuan , Liu Li‐Ping , Messersmith Phillip B.
Published: May 2012

A doubly biomimetic PMNC polymer bearing cell antifouling phosphorylcholine and mussel adhesive protein catechol groups is synthesized. The polymer can be deposited onto a variety of substrates by dip‐coating in an aqueous solution, adhering to surfaces via the catechol functional group while at the same time forming a cell outer membrane mimetic antifouling surface. Contact angle, ATR‐FTIR and XPS measurements confirm polymer coating formation on a variety of inorganic and organic substrates. BSA and bovine plasma fibrinogen protein adsorption on PMNC coated surfaces are reduced significantly compared to unmodified substrates, and platelet adhesion from human serum onto the PMNC coated substrate surfaces is highly suppressed in this study.

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Dynamic Homogeneity by Architectural Design – Bottlebrush Polymers
Authors: Grigoriadis Christos , Nese Alper , Matyjaszewski Krzysztof , Pakula Tadeusz , Butt Hans‐Jürgen , Floudas George
Published: May 2012

The self‐organization and dynamics of bottlebrush polymers consisting of poly(2‐bromoisobutyryloxyethyl methacrylate) (PBiBEM) backbone and grafted n‐butyl acrylate (PBA) chains are studied as a function of the side‐chain length by X‐ray scattering, dielectric spectroscopy, and rheology in relation to the respective homopolymers. All short‐range correlations are dominated by the PBA side chains, whereas long‐range correlations reflect the screening of the backbones by the side chains. Such correlations show up also in the segmental dynamics. The PBA segmental dynamics are slowed‐down, whereas the backbone dynamics are plasticized by the side chains. Overall the bottle‐brush architecture imparts dynamic homogeneity to the backbone and side‐chain dynamics.
Dispersing Graphene in Hydroxypropyl Cellulose by Utilizing its LCST Behavior
Authors: Liao Ruijuan , Lei Yanda , Wan Jingjing , Tang Zhenghai , Guo Baochun , Zhang Liqun
Published: May 2012

A novel method for producing graphene/hydroxypropyl cellulose (HPC) composite with a fine dispersion of graphene is established. The thermoresponsive HPC, with low a critical solution temperature (LCST) behavior, becomes self‐associated into nanospheres when its homogeneous solution is heated to a temperature higher than the LCST. The formed nanospheres of HPC can then “clamp” graphene layers and get them finely dispersed in solution and in the polymer matrix. Incorporating graphene via this method can largely prevent graphene from agglomeration. Compared with the conventional casting method, the proposed LCST method can further enhance the electrical conductivity of HPC/graphene composites by 2–3 orders of magnitude. The percolation threshold value of RGO loading is as low as 0.11 vol%.
Creep and Failure Time of Aramid Yarns Subjected to Constant Load
Authors: Knoester Henk , den Decker Piet , van den Heuvel Jurriaan , Tops Niek , Elkink Frits
Published: May 2012

The lifetime of synthetic yarns subjected to constant load is generally described by an empirical model expressing the logarithm of “time‐to‐failure” as a linear decreasing function of the applied load or, alternatively, by means of a power‐law equation. The failure of aramid yarns is systematically explored here and both models are successfully used to fit the experimental data. The models are extended to describe yarn failure on filament level. Application of these models to the experimental data shows that, independent of a visco‐elastic response, failure can be interpreted in terms of an almost constant rate damage accumulation prior to an avalanche of breaking filaments (yarn failure).

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Templation, Water Content, and Zeta Potential of Polyelectrolyte Nanoassemblies: a Comparison Between Polyelectrolyte Multilayers and Brushes
Authors: Moya Sergio Enrique , Iturri Ramos Jagoba Jon , Llarena Irantzu
Published: May 2012

This feature article deals with the self assembly and physical chemistry of polyelectrolytes: multilayers and brushes. The article highlights the interesting behavior of polyelectrolytes in nanoscale assemblies, giving more insight into the complexity of the formation of the assemblies. The water content of multilayers and brushes is studied during the assembly and in different ionic strengths. Similarities are found in the behavior of the brushes and multilayers with ionic strength, with regard to changes in the thickness and the water content. An invariance of the zeta potential with ionic strength is also observed for both systems, which can be explained as a result of conformational changes of the polymer chains. Finally, the combination of brushes and multilayers for surface modification is presented.
Catenated PS–PMMA Block Copolymers via Supramolecularly Templated ATRP Initiator Approach
Authors: Bunha Ajay Kumar , Mangadlao Joey , Felipe Mary Jane , Pangilinan Katrina , Advincula Rigoberto
Published: May 2012

A novel route to synthesize catenated macrocyclic PS–PMMA block copolymers is demonstrated via combination of supramolecular chemistry and controlled radical polymerization (CRP). Polymerization of styrene with bromopropionate ester initiator coupled with phenanthroline Cu(I) complex affords a four arm PS macroinitiator, which upon further chain extension by polymerization of MMA generates a four arm PS–PMMA block copolymer. Intramolecular coupling of PS–PMMA–Br arms via low temperature styrene‐assisted atom transfer radical coupling (ATRC) leads to the formation of PS–PMMA catenand, which generates the metal‐free catenated macrocyclic PS–PMMA block copolymer after removal of Cu metal. The interlocked structures of catenated block copolymers are confirmed by GPC, NMR, and AFM image analysis.
An Emulsifier‐Free RAFT‐Mediated Process for the Efficient Synthesis of Cerium Oxide/Polymer Hybrid Latexes
Authors: Garnier Jérôme , Warnant Jérôme , Lacroix‐Desmazes Patrick , Dufils Pierre‐Emmanuel , Vinas Jérôme , Vanderveken Yves , van Herk Alex M.
Published: May 2012

Hybrid latexes based on cerium oxide nanoparticles are synthesized via an emulsifier‐free process of emulsion polymerization employing amphiphatic macro‐RAFT agents. Poly(butyl acrylate‐co‐acrylic acid) random oligomers of various compositions and chain lengths are first obtained by RAFT copolymerization in the presence of a trithiocarbonate as controlling agent. In a second step, the seeded emulsion copolymerization of styrene and methyl acrylate is carried out in the presence of nanoceria with macro‐RAFT agents adsorbed at their surface, resulting in a high incorporation efficiency of cerium oxide nanoparticles in the final hybrid latexes, as evidenced by cryo‐transmission electron microscopy.
Effect of Nonsolvent on the Formation of Polymer Nanomaterials in the Nanopores of Anodic Aluminum Oxide Templates
Authors: Lee Chih‐Wei , Wei Tzu‐Hui , Chang Chun‐Wei , Chen Jiun‐Tai
Published: May 2012

We study the effect of nonsolvent on the formation of polymer nanomaterials in the nanopores of porous templates. Water (nonsolvent) is added into a poly (methyl methacrylate) (PMMA) solution in dimethylformamide (DMF) confined in the nanopores of an anodic aluminum oxide (AAO) template. Water forms a wetting layer on the pore wall and causes the PMMA solution to be isolated in the center of the nanopore, resulting in the formation of PMMA nanospheres or nanorods after the solvent is evaporated. The formation of the polymer nanomaterials induced by nonsolvent is found to be driven by the Rayleigh‐instability‐type transformation. Without adding the nonsolvent, PMMA chains precipitate on the walls of the nanopores after the solvent is evaporated, and PMMA nanotubes are obtained.
Dynamical analysis of impulsive neural networks with time‐varying delays
Authors: Xiang Laisheng
Published: May 2012

In this work, a new criterion concerning the global exponential stability of impulsive neural networks with time‐varying delays is presented by employing the impulsive delayed differential inequality method. The criterion is independent of the time‐varying delays and does not require the differentiability of delay functions. An example and its simulation showing the effectiveness of the present criterion is given finally. Copyright © 2012 John Wiley & Sons, Ltd.
Nutritional B vitamin deficiency disrupts lipid metabolism causing accumulation of proatherogenic lipoproteins in the aorta adventitia of ApoE null mice
Authors: McNeil Christopher J. , Beattie John H. , Gordon Margaret‐Jane , Pirie Lynn P. , Duthie Susan J.
Published: May 2012

Scope

Cardiovascular disease is the major cause of death in the world. Low dietary folate, elevated homocysteine, and high circulating cholesterol are risk factors.

Methods and results

We investigated whether folate and/or B vitamin deficiency would change lipoprotein and fatty acid metabolism and lipid accumulation in the aorta adventitia of ApoE null mice. Mice (n = 10 per group) were fed a control (C; 4%) or high saturated fat (HF; 21%), and high cholesterol (0.15%) diet for 16 weeks. Folate (F‐) or folate, B6 and B12 deficiency (F‐B‐) were imposed on these diets. Feeding a HF diet increased plasma and liver total cholesterol and HDL cholesterol (two‐ to threefold; p < 0.05). Total cholesterol increased (twofold; p < 0.05) in aorta adventitial lipid in response to HF. Feeding a diet depleted of folate and B vitamins (F‐B‐) significantly increased cholesterol accumulation in both liver and aorta adventitial lipid (approximately 50–70%; p < 0.05). Moreover, the proportions of fatty acids in hepatic and adventitial lipid was significantly changed by B vitamin depletion, measured as an increase in saturated fatty acids (approximately 15%) and a decrease (approximately 11%) in monounsaturated fatty acids (p < 0.05).

Conclusion

B vitamin deficiency perturbs lipid metabolism in ApoE null mice, causing accumulation of proatherogenic cholesterol and fatty acids in the aorta adventitia.
Arachidonic acid/docosahexaenoic acid‐supplemented diet in early life reduces body weight gain, plasma lipids, and adiposity in later life in ApoE*3Leiden mice
Authors: Wielinga Peter Y. , Harthoorn Lucien F. , Verschuren Lars , Schoemaker Marieke H. , Jouni Zeina E. , van Tol Eric A.F. , Kleemann Robert , Kooistra Teake
Published: May 2012

Scope

This study addresses whether early life arachidonic acid (ARA)/docosahexaenoic acid (DHA) supplementation or eicosapentaenoic acid (EPA)/DHA (Omacor) supplementation affects body weight gain, lipid metabolism, and adipose tissue quantity and quality in later life in ApoE*3Leiden‐transgenic mice, a humanized model for hyperlipidemia and mild obesity.

Methods and results

Four‐week‐old male ApoE*3Leiden mice were fed chow diet with or without a mixture of ARA (0.129 wt%) and DHA (0.088 wt%) or Omacor (0.30 wt% EPA, 0.25 wt% DHA). At age 12 weeks, mice were fed high‐fat/high‐carbohydrate (HFHC) diet without above supplements until age 20 weeks. Control mice received chow diet throughout the study. Mice receiving ARA/DHA gained less body weight compared to control and this effect was sustained when fed HFHC. Omacor had no significant effect on body weight gain. Plasma cholesterol and triglycerides were significantly lowered by both supplementations. At 20 weeks, epididymal fat mass was less in ARA/DHA‐supplemented mice, while Omacor had no significant effect on fat mass. Both ARA/DHA and Omacor reduced inguinal adipocyte cell size; only ARA/DHA significantly reduced epididymal macrophage infiltration.

Conclusion

This study shows that early life ARA/DHA, but not Omacor supplementation improves body weight gain later in life. ARA/DHA and to a lesser extent Omacor both improved adipose tissue quality.
Dynamic hysteresis between gradient echo and spin echo attenuations in dynamic susceptibility contrast imaging
Authors: Xu Chao , Kiselev Valerij G. , Möller Harald E. , Fiebach Jochen B.
Published: May 2012

Perfusion measurements using dynamic susceptibility contrast imaging provide additional information about the mean vessel size of microvasculature when supplemented with a dual gradient echo (GE) – spin echo (SE) contrast. Dynamic increase in the corresponding transverse relaxation rate constant changes, ΔR2GE and ΔR2SE, forms a loop on the (Δ, ΔR2GE) plane, rather than a reversible line. The shape of the loop and the direction of its passage differentiate between healthy brain and pathological tissue, such as tumour and ischemic tissue. By considering a tree model of microvasculature, the direction of the loop is found to be influenced mainly by the relative arterial and venous blood volume, as well as the tracer bolus dispersion. A parameter Λ is proposed to characterize the direction and shape of the loop, which might be considered as a novel imaging marker for describing the pathology of cerebrovascular network. Magn Reson Med 69:981–991, 2013. © 2012 Wiley Periodicals, Inc.
Micropolar hyper‐elastoplasticity: constitutive model, consistent linearization, and simulation of 3D scale effects
Authors: Bauer S. , Dettmer W. G. , Perić D. , Schäfer M.
Published: May 2012

A computational model for micropolar hyperelastic‐based finite elastoplasticity that incorporates isotropic hardening is developed. The basic concepts of the non‐linear micropolar kinematic framework are reviewed, and a thermodynamically consistent constitutive model that features Neo‐Hooke‐type elasticity and generalized von Mises plasticity is described. The integration of the constitutive initial value problem is carried out by means of an elastic‐predictor/plastic‐corrector algorithm, which retains plastic incompressibility. The solution procedure is developed carefully and described in detail. The consistent material tangent is derived. The micropolar constitutive model is implemented in an implicit finite element framework. The numerical example of a notched cylindrical bar subjected to large axial displacements and large twist angles is presented. The results of the finite element simulations demonstrate (i) that the methodology is capable of capturing the size effect in three‐dimensional elastoplastic solids in the finite strain regime, (ii) that the formulation possesses a regularizing effect in the presence of strain localization, and (iii) that asymptotically quadratic convergence rates of the Newton–Raphson procedure are achieved. Throughout this paper, effort is made to present the developments as a direct extension of standard finite deformation computational plasticity. Copyright © 2012 John Wiley & Sons, Ltd.
Topology design of reactive mufflers for enhancing their acoustic attenuation performance and flow characteristics simultaneously
Authors: Lee Jin Woo , Jang Gang‐Won
Published: May 2012

When seeking to enhance the acoustic attenuation performance of a reactive muffler, it is necessary to ensure that the flow resistance does not increase significantly. To date, there have been very few attempts to simultaneously optimize the transmission loss and pressure drop of a muffler. In this study, a multiobjective topology optimization problem is formulated to maximize the transmission loss at a target frequency and minimize the pressure drop simultaneously. The objective function in the formulation is given as the sum of weighted transmission loss and weighted pressure drop. The effect of the weighting factors on the optimal topologies of a muffler is investigated. Furthermore, the physical interpretation of partition layouts of optimized mufflers is discussed. The proposed muffler design method involving multiobjective topology optimization is compared with the previous muffler design method that involves single‐objective topology optimization to maximize only the transmission loss. The most important advantage of this study is shown by considering numerical results; the proposed muffler design method is applicable to nonconcentric expansion chamber mufflers, unlike the previous muffler design method. Copyright © 2012 John Wiley & Sons, Ltd.
Resolvins E1 and D1 inhibit interstitial fibrosis in the obstructed kidney via inhibition of local fibroblast proliferation
Authors: Qu Xinli , Zhang Xueming , Yao Jun , Song Jiangning , Nikolic‐Paterson David J , Li Jinhua
Published: May 2012

Resolvin E1 (RvE1) is a naturally occurring lipid‐derived mediator generated during the resolution of inflammation. The anti‐inflammatory effects of RvE1 have been demonstrated in a variety of disease settings; however, it is not known whether RvE1 may also exert direct anti‐fibrotic effects. We examined the potential anti‐fibrotic actions of RvE1 in the mouse obstructed kidney—a model in which tissue fibrosis is driven by unilateral ureteric obstruction (UUO), an irreversible, non‐immune insult. Administration of RvE1 (300 ng/day) to mice significantly reduced accumulation of α‐smooth muscle actin (SMA)+ myofibroblasts and the deposition of collagen IV on day 6 after UUO. This protective effect was associated with a marked reduction of myofibroblast proliferation on days 2, 4 and 6 after UUO. RvE1 treatment also inhibited production of the major fibroblast mitogen, platelet‐derived growth factor‐BB (PDGF‐BB), in the obstructed kidney. Acute resolvin treatment over days 2–4 after UUO also had a profound inhibitory effect upon myofibroblast proliferation without affecting the PDGF expression, suggesting a direct effect upon fibroblast proliferation. In vitro studies established that RvE1 can directly inhibit PDGF‐BB‐induced proliferation in primary mouse fibroblasts. RvE1 induced transient, but not sustained, activation of the pro‐proliferative ERK and AKT signalling pathways. Of note, RvE1 inhibited the sustained activation of ERK and AKT pathways seen in response to PDGF stimulation, thereby preventing up‐regulation of molecules required for progression through the cell cycle (c‐Myc, cyclin D) and down‐regulation of inhibitors of cell cycle progression (p21, cip1). Finally, siRNA‐based knock‐down studies showed that the RvE1 receptor, ChemR23, is required for the anti‐proliferative actions of RvE1 in cultured fibroblasts. In conclusion, this study demonstrates that RvE1 can inhibit fibroblast proliferation in vivo and in vitro, identifying RvE1 as a novel anti‐fibrotic therapy. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Live imaging in zebrafish reveals neu(trophil) insight into the metastatic niche
Authors: Patton E Elizabeth
Published: May 2012

Non‐cancerous immune cells can significantly contribute to tumour progression and metastases. Neutrophils associated with tumours can both promote and inhibit tumour progression, but less is known about how non‐associated immune cells contribute to cancer biology. In a recent issue of the Journal of Pathology, He and colleagues use non‐invasive, high‐resolution imaging of the whole living animal to provide a compelling glimpse at how physiological migration of neutrophils can prepare a metastatic niche and how their activities can be altered by the unintended consequences of targeted therapeutics. Copyright © 2012 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Prognosis and outcome of relapsed acute lymphoblastic leukemia: A Hong Kong pediatric hematology and Oncology Study Group report
Authors: Leung Alex Wing Kwan , Vincent Lee , Chiang Alan Kwok Shing , Lee Anselm Chi Wai , Cheng Frankie Wai Tsoi , Cheuk Daniel Ka Leung , Luk Chung Wing , Ling Siu Cheung , Li Chi Kong
Published: May 2012

Background

In 2000, the Hong Kong Pediatric Hematology Oncology Study Group started a new relapsed acute lymphoblastic leukemia (ALL) treatment protocol based on modified ALL‐REZ BFM 96 protocol aiming at improving the treatment outcome in Chinese children.

Procedure

All patients in Hong Kong with first relapse of childhood ALL were included. Patients were stratified into four risk groups (S1, S2, S3, and S4) and the treatment consisted of intensive chemotherapy followed by allogeneic hematopoietic stem cell transplantation, if indicated.

Results

Fifty‐six patients were recruited and median age at diagnosis of ALL was 4.6 (range, 0.3–17) years. The median time from initial diagnosis to relapse was 2.5 (range, 0.3–9.1) years and follow‐up time was 2.7 (range, 0–9.9) years. Forty‐nine patients (87.5%) achieved second complete remission (CR2). CR2 rates for S1, S2, S3, and S4 groups were 100%, 93%, 90%, and 67%, respectively. Five‐year overall survival (OS) was 50.5 ± 6.9% and event‐free survival (EFS) was 41.5 ± 7.1%. There was no significant difference in survival among S1, S2, and S3 groups but S4 patients performed significantly worse with 5‐year OS and EFS of 8% and 0%, respectively.

Conclusion

Children with relapsed ALL of S1–S3 risk groups could be successfully treated with intensified treatment protocol. The S4 high risk group needs more innovative approach to improve treatment outcome. Pediatr Blood Cancer 2012;59:454–460. © 2012 Wiley Periodicals, Inc.
Fertility treatments, congenital malformations, fetal loss, and childhood acute leukemia: The ESCALE study (SFCE)
Authors: Rudant Jérémie , Amigou Alicia , Orsi Laurent , Althaus Thomas , Leverger Guy , Baruchel André , Bertrand Yves , Nelken Brigitte , Plat Geneviève , Michel Gérard , Sirvent Nicolas , Chastagner Pascal , Ducassou Stéphane , Rialland Xavier , Hémon Denis , Clavel Jacqueline
Published: May 2012

Background

This study investigated the relationships between childhood acute leukemia (AL) and selective maternal and birth characteristics, including congenital malformations and the use of fertility treatment, for which the literature remains scarce.

Procedure

The national registry‐based case–control study ESCALE was carried out in France in 2003–2004. Population controls were frequency matched with cases on age and gender. Data were obtained from structured telephone questionnaires. Odds ratios (OR) and their 95% confidence intervals were estimated using unconditional regression models adjusted for potential confounders.

Results

In all, 764 cases of AL (648 lymphoblastic AL (acute lymphoblastic leukemia, ALL) and 101 myeloblastic AL) and 1,681 controls were included. The AL cases' mothers reported congenital malformations more frequently than the controls' mothers (OR = 1.5 [1.0–2.4]). ALL was significantly associated with the use of fertility treatment for the index pregnancy (OR = 1.9 [1.3–2.8]). In particular, ALL was associated with ovulation induction only (OR = 2.6 [1.6–4.3]), but not with in vitro fertilization (IVF, OR = 1.0 [0.4–2.3]) or artificial insemination (OR = 1.3 [0.5–3.9]). A positive association was also observed for the difficulty of becoming pregnant without fertility treatment (OR = 1.5 [1.0–2.1]). AL was positively associated with a history of voluntary abortion (OR = 1.4 [1.1–1.8]) but not with a history of spontaneous (OR = 0.8 [0.7–1.0]) or therapeutic (OR = 0.7 [0.5–1.1]) abortion.

Conclusion

The results suggest that subfertility in itself and ovulation induction may be associated with ALL, and support a positive association with congenital malformations. The links with the various types of fertility drugs and the underlying causes of infertility need to be investigated further. Pediatr Blood Cancer 2013;60:301–308. © 2012 Wiley Periodicals, Inc.
Resolving protein interactions and complexes by affinity purification followed by label‐based quantitative mass spectrometry
Authors: Trinkle‐Mulcahy Laura
Published: May 2012

Label‐based quantitative mass spectrometry analysis of affinity purified complexes, with its built‐in negative controls and relative ease of use, is an increasingly popular choice for defining protein–protein interactions and multiprotein complexes. This approach, which differentially labels proteins/peptides from two or more populations and combines them prior to analysis, permits direct comparison of a protein pulldown (e.g. affinity purified tagged protein) to that of a control pulldown (e.g. affinity purified tag alone) in a single mass spectrometry (MS) run, thus avoiding the variability inherent in separate runs. The use of quantitative techniques has been driven in large part by significant improvements in the resolution and sensitivity of high‐end mass spectrometers. Importantly, the availability of commercial reagents and open source identification/quantification software has made these powerful techniques accessible to nonspecialists. Benefits and drawbacks of the most popular labeling‐based approaches are discussed here, and key steps/strategies for the use of labeling in quantitative immunoprecipitation experiments detailed.
In vivo protein complex topologies: Sights through a cross‐linking lens
Authors: Bruce James E.
Published: May 2012

Proteins are a remarkable class of molecules that exhibit wide diversity of shapes or topological features that underpin protein interactions and give rise to biological function. In addition to quantitation of abundance levels of proteins in biological systems under a variety of conditions, the field of proteome research has as a primary mission the assignment of function for proteins and if possible, illumination of factors that enable function. For many years, chemical cross‐linking methods have been used to provide structural data on single purified proteins and purified protein complexes. However, these methods also offer the alluring possibility to extend capabilities to complex biological samples such as cell lysates or intact living cells where proteins may exhibit native topological features that do not exist in purified form. Recent efforts are beginning to provide glimpses of protein complexes and topologies in cells that suggest continued development will yield novel capabilities to view functional topological features of many proteins and complexes as they exist in cells, tissues, or other complex samples. This review will describe rationale, challenges, and a few success stories along the path of development of cross‐linking technologies for measurement of in vivo protein interaction topologies.
Integrating mass spectrometry of intact protein complexes into structural proteomics
Authors: Hyung Suk‐Joon , Ruotolo Brandon T.
Published: May 2012

MS analysis of intact protein complexes has emerged as an established technology for assessing the composition and connectivity within dynamic, heterogeneous multiprotein complexes at low concentrations and in the context of mixtures. As this technology continues to move forward, one of the main challenges is to integrate the information content of such intact protein complex measurements with other MS approaches in structural biology. Methods such as H/D exchange, oxidative foot‐printing, chemical cross‐linking, affinity purification, and ion mobility separation add complementary information that allows access to every level of protein structure and organization. Here, we survey the structural information that can be retrieved by such experiments, demonstrate the applicability of integrative MS approaches in structural proteomics, and look to the future to explore upcoming innovations in this rapidly advancing area.
Affinity‐purification coupled to mass spectrometry: Basic principles and strategies
Authors: Dunham Wade H. , Mullin Michael , Gingras Anne‐Claude
Published: May 2012

Identifying the interactions established by a protein of interest can be a critical step in understanding its function. This is especially true when an unknown protein of interest is demonstrated to physically interact with proteins of known function. While many techniques have been developed to characterize protein–protein interactions, one strategy that has gained considerable momentum over the past decade for identification and quantification of protein–protein interactions, is affinity‐purification followed by mass spectrometry (AP‐MS). Here, we briefly review the basic principles used in affinity‐purification coupled to mass spectrometry, with an emphasis on tools (both biochemical and computational), which enable the discovery and reporting of high quality protein–protein interactions.
Computational and informatics strategies for identification of specific protein interaction partners in affinity purification mass spectrometry experiments
Authors: Nesvizhskii Alexey I.
Published: May 2012

Analysis of protein interaction networks and protein complexes using affinity purification and mass spectrometry (AP/MS) is among most commonly used and successful applications of proteomics technologies. One of the foremost challenges of AP/MS data is a large number of false‐positive protein interactions present in unfiltered data sets. Here we review computational and informatics strategies for detecting specific protein interaction partners in AP/MS experiments, with a focus on incomplete (as opposite to genome wide) interactome mapping studies. These strategies range from standard statistical approaches, to empirical scoring schemes optimized for a particular type of data, to advanced computational frameworks. The common denominator among these methods is the use of label‐free quantitative information such as spectral counts or integrated peptide intensities that can be extracted from AP/MS data. We also discuss related issues such as combining multiple biological or technical replicates, and dealing with data generated using different tagging strategies. Computational approaches for benchmarking of scoring methods are discussed, and the need for generation of reference AP/MS data sets is highlighted. Finally, we discuss the possibility of more extended modeling of experimental AP/MS data, including integration with external information such as protein interaction predictions based on functional genomics data.
Economic survivorship stress is associated with poor health‐related quality of life among distressed survivors of hematopoietic stem cell transplantation
Authors: Hamilton Jada G. , Wu Lisa M. , Austin Jane E. , Valdimarsdottir Heiddis , Basmajian Katie , Vu AnnaMarie , Rowley Scott D. , Isola Luis , Redd William H. , Rini Christine
Published: May 2012

Background

Hematopoietic stem cell transplantation is a demanding cancer treatment associated with enduring physical and psychological complications. Survivors' well‐being may be further compromised by exposure to chronic stressors common to this population, including difficulties arising from costly medical care, changes in employment status, and health insurance coverage. Thus, we hypothesized that financial, employment, and insurance stressors (collectively referred to as economic survivorship stressors) would be associated with poorer health‐related quality of life (HRQOL) among hematopoietic stem cell transplantation survivors.

Methods

Survivors (n = 181; M = 640 days post‐transplant) completed the measures of study variables through mailed questionnaires and telephone interviews. Hierarchical regression analyses were conducted to test the hypothesized associations between economic survivorship stressors and HRQOL, and to examine whether social and situational factors interact with survivors' stress perceptions to predict HRQOL.

Results

Greater financial and employment stress were associated with poorer functioning across multiple HRQOL domains, even after controlling for the effects of possible confounding sociodemographic and medical variables. Insurance stress was not associated with HRQOL. Some associations were moderated by situational factors including timing of the current financial crisis and portion of the transplant paid for by health insurance.

Conclusions

Hematopoietic stem cell transplantation survivors can face serious economic challenges during recovery. Results suggest the value of viewing these challenges as chronic stressors capable of reducing survivors' mental and physical well‐being. Identifying resources and skills that help survivors cope with these demands is an important goal for clinicians and researchers. Copyright © 2012 John Wiley & Sons, Ltd.