bluuebunny/crossref_metadata_2025 huggingface dataset:
Synthesis and Evaluation of Lipophilic Aza‐C‐glycosides as Inhibitors of Glucosylceramide Metabolism
Authors: Wennekes Tom , van den Berg Richard J. B. H. N. , Boltje Thomas J. , Donker‐Koopman Wilma E. , Kuijper Bastiaan , van der Marel Gijsbert A. , Strijland Anneke , Verhagen Carlo P. , Aerts Johannes M. F. G. , Overkleeft Herman S.
Published: January 2010

The structure–activity relationship of lipophilic aza‐C‐glycosides as inhibitors of the three enzymes of glucosylceramide metabolism is investigated. A library of β‐aza‐C‐glycosides was synthesized with variations in N‐alkylation and the linker length/type to the lipophilic moiety. A cross‐metathesis reaction was used to prepare a second library of α‐aza‐C‐glycosides with D‐gluco, L‐ido and D‐xylo iminosugar cores possessing analogous linker variations. Evaluation of both libraries did not reveal a potent or selective inhibitor of glucosylceramide synthase. However, β‐aza‐C‐glycoside 43 was found to be a selective inhibitor of β‐glucosidase 2. The α‐aza‐C‐glycosides – especially with a D‐xylo core (e.g. 80) – proved to be very potent and selective inhibitors of glucocerebrosidase.
Facile Solid‐Phase Synthesis of AICAR 5′‐Monophosphate (ZMP) and Its 4‐N‐Alkyl Derivatives
Authors: Oliviero Giorgia , D'Errico Stefano , Borbone Nicola , Amato Jussara , Piccialli Vincenzo , Piccialli Gennaro , Mayol Luciano
Published: January 2010

We report herein a facile, solid‐phase synthesis of 5‐amino‐1‐β‐D‐ribofuranosylimidazole‐4‐carboxamide‐5′‐monophosphate (ZMP), a biosynthetic precursor of purine nucleotides, as well as a small collection of its 4‐N‐alkyl derivatives. The very difficult, direct, chemical phosphorylation of 5‐amino‐1‐β‐D‐ribofuranosylimidazole‐4‐carboxamide (AICAR) was circumvented by installing a suitable, fully protected, phosphate group on the 5′‐position of N‐1‐(2,4‐dinitrophenyl)inosine, connected to the solid support through the 2′,3′‐positions, prior to the purine degradation, which led to the 5‐amino‐imidazole‐4‐carboxamide moiety. A plausible reaction mechanism for the formation of the ZMP imidazole was also reported.
An Electrochemical DNA Biosensor for the Detection of the Apa I Polymorphism in the Vitamin D Receptor Gene Using Meldola's Blue as a Hybridization Indicator
Authors: Aladag Nilay , Ozkan‐Ariksoysal Dilsat , Gezen‐Ak Duygu , Yilmazer Selma , Ozsoz Mehmet
Published: January 2010

Electrochemical detection of nucleic acid base mismatches related to Apa I single nucleotide polymorphism (SNP) in the vitamin D receptor gene was performed successfully using 7‐dimethyl‐amino‐1,2‐benzophenoxazinium salt (Meldola's blue, MDB) with 10.9 pmol/100 μL of detection limit. MDB reduction signals obtained from probe, mismatch(probe‐SNP containing target) and hybrid(probe‐target) modified pencil graphite electrode(PGE) increased respectively. The sensor was able to clearly distinguish perfect match from mismatch DNA in a 30 min. detection time. Several factors affecting on the hybridization and indicator response are studied to maximize sensitivity and selectivity. The advantages of the biosensor are discussed in comparison with previous electrochemical assays for DNA hybridization.
A Biosensor Composed of Glucose Oxidase‐Containing Liposomes and MnO2‐Based Layered Nanocomposite
Authors: Yoshimoto Makoto , Iida Chihiro , Kariya Asuka , Takaki Noriyuki , Nakayama Masaharu
Published: January 2010

Glucose oxidase (GOD) was encapsulated in liposomes, and then the GOD‐containing liposomes were immobilized to a MnO2‐based multilayered nanocomposite film grown electrochemically. Oxidation of glucose took place on the encapsulated GOD in the manganese oxide film, and the generated H2O2 molecules were oxidized catalytically at high valent Mn sites (4+) in the film. Anodic currents due to reoxidation of the reduced Mn ions (3+) were in proportion to the concentration of glucose from 19.6 to 107.1 mM. Such a simple construction of biosensor is applicable to a variety of combinations of liposomal enzymes and substrates.
Recent developments in peptide stereoisomer separations by capillary electromigration techniques
Authors: Scriba Gerhard K. E.
Published: January 2010

The stereochemistry of peptides determines their physicochemical and biological activities. Thus, analytical methods that are able to discriminate between peptide stereoisomers are important. As peptides are typically hydrophilic compounds, many methods for the separation of peptide diastereomers and enantiomers have been developed by capillary electromigration techniques. Moreover, peptide enantiomers displayed unique migration behavior such as a pH‐dependent change of the enantiomer migration order in CD‐mediated enantioseparations in CE making them ideal compounds to study mechanistic effects of enantioseparations. The present short review summarizes recent developments in the separation of stereoisomers of peptide and peptidomimetics by capillary electromigration techniques. Moreover, recent NMR and molecular modeling studies as well as investigation on the effect of buffer additives on complex formation will be discussed as attempts to understand mechanistic aspects of peptide enantioseparations and to analyze the structure of peptide‐CD complexes.
Membrane proteins and proteomics: Love is possible, but so difficult
Authors: Rabilloud Thierry
Published: January 2010

Despite decades of extensive research, the large‐scale analysis of membrane proteins remains a difficult task. This is due to the fact that membrane proteins require a carefully balanced hydrophilic and lipophilic environment, which optimum varies with different proteins, while most protein chemistry methods work mainly, if not only, in water‐based media. Taking this review [Santoni, Molloy and Rabilloud, Membrane proteins and proteomics: un amour impossible? Electrophoresis 2000, 21, 1054–1070] as a pivotal paper, the current paper analyzes how the field of membrane proteomics exacerbated the trend in proteomics, i.e. developing alternate methods to the historical two‐dimensional electrophoresis, and thus putting more and more pressure on the mass spectrometry side. However, in the case of membrane proteins, the incentive in doing so is due to the poor solubility of membrane proteins. This review also shows that in some situations, where this solubility problem is less acute, two‐dimensional electrophoresis remains a method of choice. Last but not least, this review also critically examines the alternate approaches that have been used for the proteomic analysis of membrane proteins.
Electrophoresis of DNA in agarose gels, polyacrylamide gels and in free solution
Authors: Stellwagen Nancy C.
Published: January 2010

This review describes the electrophoresis of curved and normal DNA molecules in agarose gels, polyacrylamide gels and in free solution. These studies were undertaken to clarify why curved DNA molecules migrate anomalously slowly in polyacrylamide gels but not in agarose gels. Two milestone papers are cited, in which Ferguson plots were used to estimate the effective pore size of agarose and polyacrylamide gels. Subsequent studies on the effect of the electric field on agarose and polyacrylamide gel matrices, DNA interactions with the two gel matrices, and the effect of curvature on the free solution mobility of DNA are also described. The combined results suggest that the anomalously slow mobilities observed for curved DNA molecules in polyacrylamide gels are primarily due to preferential interactions of curved DNAs with the polyacrylamide gel matrix; the restrictive pore size of the matrix is of lesser importance. In free solution, DNA mobilities increase with increasing molecular mass until leveling off at a plateau value of (3.17±0.01)×10−4 cm2/V s in 40 mM Tris‐acetate‐EDTA buffer at 20°C. Curved DNA molecules migrate anomalously slowly in free solution as well as in polyacrylamide gels, explaining why the Ferguson plots of curved and normal DNAs containing the same number of base pairs extrapolate to different mobilities at zero gel concentration.
Electrophoretic sample stacking
Authors: Gebauer Petr , Boček Petr
Published: January 2010

Sample stacking is a tool that is in daily use in electrophoresis in order to enhance the efficiency and sensitivity of analyses. The application of sample stacking is described by numerous diverse practical procedures and numerous different names. This contribution shows that the present intricate situation is a heritage of the history where chromatographic and isotachophoretic approaches have been applied more or less independently. Further, this contribution shows that a unified view is possible and a general approach based on a frame with moving self‐sharpening boundary may provide the required fundamental theory and criteria needed for successful application of sample stacking. Finally, the prospects of sample stacking are discussed.
Chiral separations by CE employing CDs
Authors: Fanali Salvatore
Published: January 2010

This paper summarizes the history of chiral separations done by using electromigration methods with CDs. Several enantioresolution mechanisms and a wide number of chiral selectors have been applied to the separation of optical isomers by CE. Among them inclusion‐complexation with CDs or their derivatives played a very important role in CE. Since the beginning our group was involved in studying method optimization for enantiomer resolution by using these chiral selectors. One of our publications was the basis for further development in the field, at least for us. New chiral selectors, development of theory, new methodological approaches and a wide number of practical applications are the main results achieved in the last almost 25 years using CE as an enantioseparative technique.
Dynamic computer simulations of electrophoresis: Three decades of active research
Authors: Thormann Wolfgang , Caslavska Jitka , Breadmore Michael C. , Mosher Richard A.
Published: January 2010

Dynamic models for electrophoresis are based upon model equations derived from the transport concepts in solution together with user‐inputted conditions. They are able to predict theoretically the movement of ions and are as such the most versatile tool to explore the fundamentals of electrokinetic separations. Since its inception three decades ago, the state of dynamic computer simulation software and its use has progressed significantly and Electrophoresis played a pivotal role in that endeavor as a large proportion of the fundamental and application papers were published in this periodical. Software is available that simulates all basic electrophoretic systems, including moving boundary electrophoresis, zone electrophoresis, ITP, IEF and EKC, and their combinations under almost exactly the same conditions used in the laboratory. This has been employed to show the detailed mechanisms of many of the fundamental phenomena that occur in electrophoretic separations. Dynamic electrophoretic simulations are relevant for separations on any scale and instrumental format, including free‐fluid preparative, gel, capillary and chip electrophoresis. This review includes a historical overview, a survey of current simulators, simulation examples and a discussion of the applications and achievements of dynamic simulation.
Proteomics in the study of the molecular taxonomy and epidemiology of bacterial pathogens
Authors: Cash Phillip
Published: January 2010

The ability to discriminate bacterial isolates is important for a number of areas of research in Medical Microbiology, particularly in defining bacterial taxonomy and monitoring transmission in epidemiological investigations. Molecular techniques capable of typing bacteria at the level of the genome and proteome are now widely used for these investigations. This review considers two electrophoretic methods for typing bacteria on the basis of their proteomes, namely 1‐D SDS‐PAGE and 2‐DE. The application of these two techniques for bacterial typing is described with reference to two publications that appeared in Electrophoresis [Costa, Electrophoresis 1990, 11, 382–391 and Cash et al., Electrophoresis 1997, 18, 1472–1482]. Even though these methods have been used for nearly 20 years to differentiate bacterial isolates they remain key technologies in proteome‐based typing methods. The developments that have arisen from the two key papers are described in order to highlight the advantages and disadvantages in typing bacteria at the level of their proteomes. Some of the difficulties associated with electrophoretic typing methods can be overcome by using non‐gel proteomic methods based on MS to provide improved sensitivity and specificity. The application of proteomic methods to investigate bacterial taxonomy, epidemiology and pathogenesis in general has significant potential in furthering our understanding of infectious diseases.
Affinity in Electrophoresis
Authors: Heegaard Niels H. H.
Published: January 2010

The journal Electrophoresis has greatly influenced my approaches to biomolecular affinity studies. The methods that I have chosen as my main tools to study interacting biomolecules – native gel and later capillary zone electrophoresis – have been the topic of numerous articles in Electrophoresis. Below, the role of the journal in the development and dissimination of these techniques and applications reviewed. Many exhaustive reviews on affinity electrophoresis and affinity CE have been published in the last few years and are not in any way replaced by the present deliberations that are focused on papers published by the journal.
From 2‐D electrophoresis to proteomics
Authors: Klose Joachim
Published: January 2010

At first, a short history of the beginning of 2‐DE is provided. Based on the present state of the art at the time I developed a 2‐DE technique in 1975 that was able to resolve complex protein extracts from mouse tissues in hundreds of protein spots. My intention was to study proteins from a global point of view. Questions of interest were, how do proteins change during embryonic development, and what is the effect of induced mutations on the protein level. At that time protein chemistry was a matter of analyzing single proteins in detail. Therefore, my approach was frequently criticized as inappropriate because it would be impossible to identify and characterize the hundreds of proteins resolved. But soon it was realized that studying total proteins gives opportunities to answer many interesting questions. This led to a research field nowadays called “proteomics”. Already in the beginning of the 1980s the idea to analyze the total human proteins had come up. By entering the post‐genome era it became obvious that a human proteome project is needed in order to explain the human genome in terms of its functions. The problems in realizing such a project are considered.
Theory of electrophoresis: Fate of one equation
Authors: Gaš Bohuslav
Published: January 2010

Electrophoresis utilizes a difference in movement of charged species in a separation channel or space for their spatial separation. A basic partial differential equation that results from the balance laws of continuous processes in separation sciences is the nonlinear conservation law or the continuity equation. Attempts at its analytical solution in electrophoresis go back to Kohlrausch's days. The present paper (i) reviews derivation of conservation functions from the conservation law as appeared chronologically, (ii) deals with theory of moving boundary equations and, mainly, (iii) presents the linear theory of eigenmobilities. It shows that a basic solution of the linearized continuity equations is a set of traveling waves. In particular cases the continuity equation can have a resonance solution that leads in practice to schizophrenic dispersion of peaks or a chaotic solution, which causes oscillation of electrolyte solutions.
DNA gel electrophoresis: The reptation model(s)
Authors: Slater Gary W.
Published: January 2010

DNA gel electrophoresis has been the most important experimental tool to separate DNA fragments for several decades. The introduction of PFGE in the 1980s and capillary gel electrophoresis in the 1990s made it possible to study, map and sequence entire genomes. Explaining how very large DNA molecules move in a gel and why PFGE is needed to separate them has been an active field of research ever since the launch of the journal Electrophoresis. This article presents a personal and historical overview of the development of the theory of gel electrophoresis, focusing on the reptation model, the band broadening mechanisms, and finally the factors that limit the read length and the resolution of electrophoresis‐based sequencing systems. I conclude with a short discussion of some of the questions that remain unanswered.
From micro to macro: Conversion of capillary electrophoretic separations of biomolecules and bioparticles to preparative free‐flow electrophoresis scale
Authors: Kašička Václav
Published: January 2010

This invited contribution in the special issue of Electrophoresis published in celebration of the 30th Anniversary of this journal reflects the impact of our milestone paper [Prusík, Z., Kašička, V., Mudra, P., Štěpánek, J., Smékal, O., Hlaváček, J., Electrophoresis 1990, 11, 932–936] in the area of conversion of microscale analytical and micropreparative CE separations of biomolecules and bioparticles into (macro)preparative free‐flow electrophoresis (FFE) scale on the basis of a correlation between CE and FFE methods. In addition to the survey of advances in the relatively narrow field of CE‐FFE correlation and CE‐FFE conversion, a comprehensive review of the recent developments of micropreparative CE and (macro)preparative FFE techniques is also presented and applications of these techniques to micro‐ and (macro)preparative separations and purifications of biomolecules and bioparticles are demonstrated. The review covers the period since the year of publication of the above paper, i.e. ca. the last 20 years.
Combined use of mild oxidation and cutinase/lipase pretreatments for enzymatic processing of wool fabrics
Authors: Wang Ping , Cui Li , Wang Qiang , Fan Xuerong , Zhao Xianfei , Wu Jing
Published: January 2010

A cutinase from Thermobifida fusca WSH04 and two lipases, L3126 and Lipex 100L, were applied to the enzymatic pretreatment of wool fabrics followed by protease treatment, aiming at hydrolyzing the outmost bound lipids on the wool surface. A mild oxidation with 2 g/L hydrogen peroxide (30%) was selectively carried out before the enzymatic treatments. The cooperative actions of mild oxidation, cutinase and lipase pretreatments during wool processing were investigated. The results showed that lipase pretreatment alone had less impact on the wettability and anti‐felting ability of wool fabrics than cutinase treatment. Combined use of cutinase and lipase pretreatments did not evidently improve the properties of the wool fabric compared with the individual cutinase pretreatment. By contrast, mild oxidation slightly enhanced the activity of cutinase toward the wool surface and promoted the subsequent proteolytic reactions. The wetting time and contact angle of the protease‐treated fabric deceased to 1.2 min and 55°, respectively; the area shrinkage decreased to 3.1%, with an acceptable strength loss from 489 to 418 N. The changes in the cuticle scales of the wool fibers, confirmed by scanning electron microscopy, further proved the cooperative actions of mild oxidation and cutinase pretreatment during enzymatic wool processing.
Chondrogenesis of articular chondrocytes in hydroxyapatite/chitin/chitosan scaffolds supplemented with pituitary extract
Authors: Kuo Yung‐Chih , Leou Sho‐Noen
Published: January 2010

This study analyzes the effects of pituitary extract supplement on the cultivation of bovine knee chondrocytes (BKCs) in three‐dimensional chitin/chitosan biomaterials. Transforming growth factor‐β1 (TGF‐β1) in the supplement was identified by Western blot near 23 kDa, and the immunoassayed concentration of TGF‐β1 in the supplement was about 33 ng/mL. The typical pore diameter of the chitin/chitosan scaffolds was 250 μm, indicating an apposite void space for chondrocyte growth. The characteristic width of needlelike hydroxyapatite crystals was 85 nm after chemical co‐precipitation of hydroxyapatite on the pore surfaces of the scaffolds. Over 4‐wk cultivation, the amounts of proliferated BKCs, secreted glycosaminoglycans and produced collagen were improved with the concentration of TGF‐β1 in culture medium. In addition, the cultivated constructs revealed mature neocartilage with lacunas enclosing BKCs, demonstrating chondrogenesis. Pituitary extract supplement was more efficient in the synthesis of extracellular matrix than pure TGF‐β1. Hence, an appropriate addition of the supplement can enhance the formation of cartilaginous components in the scaffolds to regenerate articular cartilage.
Daily morphological changes determined by high‐energy events on an embayed beach: a qualitative model
Authors: Martins Cristina Celia , de Mahiques Michel Michaelovitch , Dias João Manuel Alveirinho
Published: January 2010

This paper examines the daily morphological responses of Sununga Beach, an embayed beach located on the south‐eastern Brazilian coast, to storms in the South Atlantic Ocean. The main mechanisms and timing of beach erosion and accretion, the relationship between wave height and direction, and beach volume changes are considered, to establish a qualitative model for short‐term embayed beach morphological changes.

The methodology consisted of daily topographic surveys during the month of May in 2001, 2002, and 2003, using an RTK‐GPS (real‐time kinematics – global positioning system). Weather and wave model results were used to correlate hydrodynamics and beach morphology.

The results indicate that the morphodynamics of Sununga Beach are characterized by a process of beach rotation, which occurred more or less clearly during all three surveys. Unlike what has been commonly described in the literature for longer time intervals and alternations of fair and stormy weather, the beach rotation processes on Sununga Beach occurred under conditions of moderate‐to‐high wave energy change (wave heights greater than 2 m).

An integrated evaluation of the behaviour of the meteorological aspects, together with beach morphology, enabled us to recognize that extra‐tropical cyclones were the most important agent in remobilizing the beach planform, whether in beach rotation or in cross‐shore erosion. Copyright © 2010 John Wiley & Sons, Ltd.
Dynamics of suspended sediment transport and yield in a large agricultural catchment, southwest France
Authors: Oeurng Chantha , Sauvage Sabine , Sánchez‐Pérez José‐Miguel
Published: January 2010

The dynamics of suspended sediment transport were monitored continuously in a large agricultural catchment in southwest France from January 2007 to March 2009. The objective of this paper is to analyse the temporal variability in suspended sediment transport and yield in that catchment. Analyses were also undertaken to assess the relationships between precipitation, discharge and suspended sediment transport, and to interpret sediment delivery processes using suspended sediment‐discharge hysteresis patterns. During the study period, we analysed 17 flood events, with high resolution suspended sediment data derived from continuous turbidity and automatic sampling. The results revealed strong seasonal, annual and inter‐annual variability in suspended sediment transport. Sediment was strongly transported during spring, when frequent flood events of high magnitude and intensity occurred. Annual sediment transport in 2007 yielded 16 614 tonnes, representing 15 t km−2 (85% of annual load transport during floods for 16% of annual duration), while the 2008 sediment yield was 77 960 tonnes, representing 70 t km−2 (95% of annual load transport during floods for 20% of annual duration). Analysis of the relationships between precipitation, discharge and suspended sediment transport showed that there were significant correlations between total precipitation, peak discharge, total water yield, flood intensity and sediment variables during the flood events, but no relationship with antecedent conditions. Flood events were classified in relation to suspended sediment concentration (SSC)–discharge hysteretic loops, complemented with temporal dynamics of SSC–discharge ranges during rising and falling flow. The hysteretic shapes obtained for all flood events reflected the distribution of probable sediment sources throughout the catchment. Regarding the sediment transport during all flood events, clockwise hysteretic loops represented 68% from river deposited sediments and nearby source areas, anticlockwise 29% from distant source areas, and simultaneity of SSC and discharge 3%. Copyright © 2010 John Wiley & Sons, Ltd.
Predicting wetted width in any river at any discharge
Authors: Booker D.J.
Published: January 2010

Coefficients describing at‐a‐station power‐law relationships between discharge and width were calculated by applying multilevel models to field data collected during routine hydrological monitoring at 326 gauging stations across New Zealand. These hydraulic geometry coefficients were then estimated for each of these stations using standard stepwise multiple‐linear regression models. Analysis was carried out to quantify how the relationship between width and discharge changed in relation to several available explanatory variables. All coefficients describing the at‐a‐station hydraulic geometry were found to have statistically significant relationships with catchment area. Statistically significant relationships between each of the coefficients were also found with the addition of catchment climate as an explanatory variable. Further statistically significant relationships were found when station elevation and channel slope, as well as hydrological source of flow and landcover of the upstream catchment were added to the explanatory variables. The level of confidence that can be associated with estimates of width at ungauged sites, and sites with limited data availability, was then assessed by comparing model predictions with independent paired data on observed width and discharge from 197 sites. When compared against these independent data, model predictions of width were improved with the addition of predictor variables of the hydraulic geometry coefficients. The greatest improvements were made when climate was added to catchment area as predictor variables. Minor improvements were made when all available information was used to predict width at these independent sites. Although the analysis was purely empirical, results describing relationships between hydraulic geometry coefficients and catchment characteristics corresponded well with knowledge of the processes controlling at‐a‐station hydraulic geometry of river width. Copyright © 2010 John Wiley & Sons, Ltd.
A numerical investigation of side‐loads resulting from rigid body motions of an overexpanded engine nozzle
Authors: Lefrançois E.
Published: January 2010

A numerical model for fluid–structure interactions is presented. Its purpose, within the context of 2D overexpanded engine nozzles, is to improve understanding of interactions between side‐loads and rigid body rotations, and more generally of the underlying physics between a shock in motion and nozzle movements. The model is based on three different solvers, for fluid, structure and mesh deformation respectively, which are linked to a coupling scheme in a parallel environment. In particular it is shown that the nozzle has a natural torsional frequency for which the measured side‐loads are the greatest. This phenomenon is associated with a transversal wave in the flow between the two internal walls of the nozzle. For free coupling cases, our calculations go some way to explain how the mechanical energy is dissipated with a transfer of energy to the shock that encounters the largest motions to dissipate it. It has also been observed that the compression shock may adopt a quasi‐steady state response with regard to nozzle rotations at low frequencies, whereas this will no longer be the case at higher frequencies, where a phase shift may occur between side‐loads and rotational position. This study is aimed at enhancing the only current aeroelastic stability model for overexpanded nozzles (AIAA, 29th Joint Propulsion Conference and Exhibit, Monterey, CA, 28–30 June 1993). Copyright © 2010 John Wiley & Sons, Ltd.
Conditional and syllogistic deductive tasks dissociate functionally during premise integration
Authors: Reverberi Carlo , Cherubini Paolo , Frackowiak Richard S.J. , Caltagirone Carlo , Paulesu Eraldo , Macaluso Emiliano
Published: January 2010

Deduction allows us to draw consequences from previous knowledge. Deductive reasoning can be applied to several types of problem, for example, conditional, syllogistic, and relational. It has been assumed that the same cognitive operations underlie solutions to them all; however, this hypothesis remains to be tested empirically. We used event‐related fMRI, in the same group of subjects, to compare reasoning‐related activity associated with conditional and syllogistic deductive problems. Furthermore, we assessed reasoning‐related activity for the two main stages of deduction, namely encoding of premises and their integration. Encoding syllogistic premises for reasoning was associated with activation of BA 44/45 more than encoding them for literal recall. During integration, left fronto‐lateral cortex (BA 44/45, 6) and basal ganglia activated with both conditional and syllogistic reasoning. Besides that, integration of syllogistic problems additionally was associated with activation of left parietal (BA 7) and left ventro‐lateral frontal cortex (BA 47). This difference suggests a dissociation between conditional and syllogistic reasoning at the integration stage. Our finding indicates that the integration of conditional and syllogistic reasoning is carried out by means of different, but partly overlapping, sets of anatomical regions and by inference, cognitive processes. The involvement of BA 44/45 during both encoding (syllogisms) and premise integration (syllogisms and conditionals) suggests a central role in deductive reasoning for syntactic manipulations and formal/linguistic representations. Hum Brain Mapp, 2010. © 2010 Wiley‐Liss, Inc.
Effective functional mapping of fMRI data with support‐vector machines
Authors: Lee Sangkyun , Halder Sebastian , Kübler Andrea , Birbaumer Niels , Sitaram Ranganatha
Published: January 2010

There is a growing interest in using support vector machines (SVMs) to classify and analyze fMRI signals, leading to a wide variety of applications ranging from brain state decoding to functional mapping of spatially and temporally distributed brain activations. Studies so far have generated functional maps using the vector of weight values generated by the SVM classification process, or alternatively by mapping the correlation coefficient between the fMRI signal at each voxel and the brain state determined by the SVM. However, these approaches are limited as they do not incorporate both the information involved in the SVM prediction of a brain state, namely, the BOLD activation at voxels and the degree of involvement of different voxels as indicated by their weight values. An important implication of the above point is that two different datasets of BOLD signals, presumably obtained from two different experiments, can potentially produce two identical hyperplanes irrespective of their differences in data distribution. Yet, the two sets of signal inputs could correspond to different functional maps. With this consideration, we propose a new method called Effect Mapping that is generated as a product of the weight vector and a newly computed vector of mutual information between BOLD activations at each voxel and the SVM output. By applying this method on neuroimaging data of overt motor execution in nine healthy volunteers, we demonstrate higher decoding accuracy indicating the greater efficacy of this method. Hum Brain Mapp, 2010. © 2010 Wiley‐Liss, Inc.
Dissociation Between Liver Inflammation and Hepatocellular Damage Induced by Carbon Tetrachloride in Myeloid Cell–Specific Signal Transducer and Activator of Transcription 3 Gene Knockout Mice
Authors: Horiguchi Norio , Lafdil Fouad , Miller Andrew M. , Park Ogyi , Wang Hua , Rajesh Mohanraj , Mukhopadhyay Partha , Fu Xin Yuan , Pacher Pal , Gao Bin
Published: January 2010

Liver injury is associated with inflammation, which is generally believed to accelerate the progression of liver diseases; however, clinical data show that inflammation does not always correlate with hepatocelluar damage in some patients. Investigating the cellular mechanisms underlying these events using an experimental animal model, we show that inflammation may attenuate liver necrosis induced by carbon tetrachloride (CCl4) in myeloid-specific signal transducer and activator of transcription 3 (STAT3) knockout mice. As an important anti-inflammatory signal, conditional deletion of STAT3 in myeloid cells results in markedly enhanced liver inflammation after CCl4 injection. However, these effects are also accompanied by reduced liver necrosis, correlating with elevated serum interleukin-6 (IL-6) and hepatic STAT3 activation. An additional deletion of STAT3 in hepatocytes in myeloid-specific STAT3 knockout mice restored hepatic necrosis but decreased liver inflammation.

Conclusion:

Inflammation-mediated STAT3 activation attenuates hepatocellular injury induced by CCl4 in myeloid-specific STAT3 knockout mice, suggesting that inflammation associated with a predominance of hepatoprotective cytokines that activate hepatic STAT3 may reduce rather than accelerate hepatocellular damage in patients with chronic liver diseases. Hepatology 2010
Antituberculosis Therapy–Induced Acute Liver Failure: Magnitude, Profile, Prognosis, and Predictors of Outcome
Authors: Kumar Ramesh , Shalimar  , Bhatia Vikram , Khanal Shankar , Sreenivas V. , Gupta Datta S. , Panda Subrat K. , Acharya Subrat K.
Published: January 2010

Antituberculosis therapy (ATT)–associated acute liver failure (ATT-ALF) is the commonest drug-induced ALF in South Asia. Prospective studies on ATT-ALF are lacking. The current study prospectively evaluated the magnitude, clinical course, outcome, and prognostic factors in ATT-ALF. From January 1986 to January 2009, 1223 consecutive ALF patients were evaluated: ATT alone was the cause in 70 (5.7%) patients. Another 15 (1.2%) had ATT and simultaneous hepatitis virus infection. In 44 (62.8%) patients, ATT was prescribed empirically without definitive evidence of tuberculosis. ATT-ALF patients were younger (32.87 [±15.8] years), and 49 (70%) of them were women. Most had hyperacute presentation; the median icterus encephalopathy interval was 4.5 (0-30) days. The median duration of ATT before ALF was 30 (7-350) days. At presentation, advanced encephalopathy and cerebral edema were present in 51 (76%) and 29 (41.4%) patients, respectively. Gastrointestinal bleed, seizures, infection, and acute renal failure were documented in seven (10%), five (7.1%), 26 (37.1%), and seven (10%) patients, respectively. Compared with hepatitis E virus (HEV) and non-A non-E–induced ALF, ATT-ALF patients had nearly similar presentations except for older age and less elevation of liver enzymes. The mortality rate among patients with ATT-ALF was high (67.1%, n = 47), and only 23 (32.9%) patients recovered with medical treatment. In multivariate analysis, three factors independently predicted mortality: serum bilirubin (≥10.8 mg/dL), prothrombin time (PT) prolongation (≥26 seconds), and grade III/IV encephalopathy at presentation.

Conclusion:

ATT-ALF constituted 5.7% of ALF at our center and had a high mortality rate. Because the mortality rate is so high, determining which factors are predictors is less important. A high proportion of patients had consumed ATT empirically, which could have been prevented. Hepatology 2010
Accelerated Liver Regeneration and Hepatocarcinogenesis in Mice Overexpressing Serine-45 Mutant β-Catenin
Authors: Nejak-Bowen Kari N. , Thompson Michael D. , Singh Sucha , Bowen William C. , Dar Mohd Jamal , Khillan Jaspal , Dai Chunsun , Monga Satdarshan P.S.
Published: January 2010

The Wnt/β-catenin pathway is implicated in the pathogenesis of hepatocellular cancer (HCC). We developed a transgenic mouse (TG) in the FVB strain that overexpresses Ser45-mutated-β-catenin in hepatocytes to study the effects on liver regeneration and cancer. In the two independent TG lines adult mice show elevated β-catenin at hepatocyte membrane with no increase in the Wnt pathway targets cyclin-D1 or glutamine synthetase. However, TG hepatocytes upon culture exhibit a 2-fold increase in thymidine incorporation at day 5 (D5) when compared to hepatocytes from wildtype FVB mice (WT). When subjected to partial hepatectomy (PH), dramatic increases in the number of hepatocytes in S-phase are evident in TG at 40 and WT at 72 hours. Coincident with the earlier onset of proliferation, we observed nuclear translocation of β-catenin along with an increase in total and nuclear cyclin-D1 protein at 40 hours in TG livers. To test if stimulation of β-catenin induces regeneration, we used hydrodynamic delivery of Wnt-1 naked DNA to control mice, which prompted an increase in Wnt-1, β-catenin, and known targets, glutamine synthetase (GS) and cyclin-D1, along with a concomitant increase in cell proliferation. β-Catenin-overexpressing TG mice, when followed up to 12 months, showed no signs of spontaneous tumorigenesis. However, intraperitoneal delivery of diethylnitrosamine (DEN), a known carcinogen, induced HCC at 6 months in TG mice only. Tumors in TG livers showed up-regulation of β-catenin, cyclin-D1, and unique genetic aberrations, whereas other canonical targets were unremarkable.

Conclusion:

β-Catenin overexpression offers growth advantage during liver regeneration. Also, whereas no spontaneous HCC is evident, β-catenin overexpression makes TG mice susceptible to DEN-induced HCC. Hepatology 2010
A Role for the Pregnane X Receptor in Flucloxacillin-Induced Liver Injury
Authors: Andrews Elise , Armstrong Martin , Tugwood Jonathan , Swan Dan , Glaves Philip , Pirmohamed Munir , Aithal Guruprasad P. , Wright Matthew C. , Day Christopher P. , Daly Ann K.
Published: January 2010

Drug-induced liver injury (DILI) due to flucloxacillin is a rare but serious complication of treatment. There is some evidence that flucloxacillin is a human pregnane X receptor (PXR) agonist. This study was designed to investigate the relevance of PXR to flucloxacillin toxicity and to identify genes changing in expression in response to flucloxacillin. Changes in gene expression in human hepatocytes after treatment with 500 μM flucloxacillin for 72 hours were examined by expression microarray analysis. The ability of flucloxacillin to act as a PXR agonist was investigated with reporter gene experiments. Flucloxacillin DILI cases (n = 51), drug-exposed controls without toxicity (n = 64), and community controls (n = 90) were genotyped for three common PXR polymorphisms. Luciferase reporter assays were used to assess the significance of a promoter region PXR polymorphism. Seventy-two probe sets representing 50 different genes showed significant changes in expression of 1.2-fold or higher. Most genes showing changes greater than 3-fold were known to be rifampicin-responsive, and this suggested a PXR-dependent mode of regulation. Using a luciferase-everted repeat separated by 6 base pairs element construct, we confirmed that flucloxacillin was a PXR agonist. We found a difference in the distribution of a PXR polymorphism (rs3814055; C-25385T) between flucloxacillin DILI cases and controls with the CC genotype associated with an increased risk of disease (odds ratio = 3.37, 95% confidence interval = 1.55-7.30,

P

= 0.0023). Reporter gene experiments showed lower promoter activity for the C allele than the T allele.

Conclusion:

Flucloxacillin is a PXR agonist at pharmacologically relevant concentrations, and a functionally significant upstream PXR polymorphism is a risk factor for flucloxacillin-induced DILI. Hepatology 2010
Inhibitory Role of Peroxisome Proliferator-Activated Receptor Gamma in Hepatocarcinogenesis in Mice and in Vitro
Authors: Yu Jun , Shen Bo , Chu Eagle S. H. , Teoh Narci , Cheung Kin-Fai , Wu Chung-Wah , Wang Shiyan , Lam Cleo N. Y. , Feng Hai , Zhao Junhong , Cheng Alfred S. L. , To Ka-Fai , Chan Henry L. Y. , Sung Joseph J. Y.
Published: January 2010

Although peroxisome proliferator-activated receptor gamma (PPARγ) agonist have been shown to inhibit hepatocellular carcinoma (HCC) development, the role of PPARγ in hepatocarcinogenesis remains unclear. We investigated the therapeutic efficacy of PPARγ against HCC. PPARγ-deficient (PPARγ+/−) and wild-type (PPARγ+/+) littermates were used in a diethylnitrosamine (DEN)-induced HCC model and treated with PPARγ agonist (rosiglitazone) or the vehicle alone for 8 months. The effects of PPARγ on HCC cell growth and apoptosis were examined using PPARγ-expressing adenovirus (Ad-PPARγ). PPARγ+/− mice were more susceptible to DEN-induced HCC than PPARγ+/+ mice (94% versus 62%,

P

< 0.05), and rosiglitazone significantly reduced the incidence of HCC in PPARγ+/+ mice (vehicle 62% versus treatment 24%,

P

< 0.01), but not in PPARγ+/− mice, indicating that PPARγ suppresses hepatocellular carcinogenesis. A pronounced expression of PPARγ was observed in a HCC cell line (Hep3B) infected with Ad-PPARγ. Such induction markedly suppressed HCC cell viability (

P

< 0.01). Further, Hep3B infection with Ad-PPARγ revealed a decreased proportion of cells in S-phase (12.92% versus 11.58%,

P

< 0.05), with arrest at G2/M phase (38.2% versus 55.68%,

P

< 0.001), and there was concomitant phosphorylation of the key G2/M phase inhibitors cdc25C and cdc2. PPARγ overexpression increased cell apoptosis (21.47% versus 35.02%,

P

< 0.01), mediated by both extrinsic (Fas and tumor necrosis factor-α) and intrinsic (caspase-9, caspase-3, caspase-7, and poly[ADP-ribose] polymerase) pathways. Moreover, PPARγ directly induced a putative tumor suppressor gene, growth differentiation factor-15.

Conclusion:

Loss of one PPARγ allele is sufficient to enhance susceptibility to HCC. PPARγ suppresses tumor cell growth through reducing cell proliferation and inducing G2/M phase arrest, apoptosis, and up-regulating growth differentiation factor-15. Thus, PPARγ acts as a tumor-suppressor gene in the liver. Hepatology 2010
Promoter hypomethylation and upregulation of trefoil factors in prostate cancer
Authors: Vestergaard Else Marie , Nexø Ebba , Tørring Niels , Borre Michael , Ørntoft Torben Falck , Sørensen Karina Dalsgaard
Published: January 2010

Trefoil factors, mucin‐associated peptides, are overexpressed in prostate cancer (PC). We hypothesized that promoter methylation contributes to the regulation of trefoil factors (TFF1, TFF2 and TFF3) in human prostate cells. Here we show hypomethylation of promoter regions of TFF1 and TFF3 in PC cell lines with significant TFF expression as compared to benign immortalized prostate cell lines and PC cell lines not expressing trefoil factor. The most striking difference was observed for CpG sites located close to the AUG start codon overlapping several putative binding sites for cellular transcription factors. TFF2 was hypermethylated and had no or very low expression in all prostate cell lines investigated. Treatment of methylated cell lines with 5‐aza‐2′‐deoxycytidine restored TFF expression in cell lines not expressing TFF and increased expression significantly in low‐expressing cell lines. In clinical samples, methylation of the promoter/enhancer regions of TFF1 and TFF3 was significantly lower in PC compared to benign prostatic hyperplasia. The present study shows an inverse relation between promoter methylation and expression of trefoil factors. Preliminary analysis on clinical samples suggests that this regulatory mechanism is responsible for the increased levels of TFF1 and TFF3 observed in PC. The overexpression and promoter hypomethylation of trefoil factors may serve as biomarkers in PC.
Flavokawain B, a kava chalcone, induces apoptosis via up‐regulation of death‐receptor 5 and Bim expression in androgen receptor negative, hormonal refractory prostate cancer cell lines and reduces tumor growth
Authors: Tang Yaxiong , Li Xuesen , Liu Zhongbo , Simoneau Anne R. , Xie Jun , Zi Xiaolin
Published: January 2010

Limited success has been achieved in extending the survival of patients with metastatic and hormone‐refractory prostate cancer (HRPC). There is a strong need for novel agents in the treatment and prevention of HRPC. We have shown that flavokawain B (FKB), a kava chalcone, is about 4‐ to 12‐fold more effective in reducing the cell viabilities of androgen receptor (AR)‐negative, HRPC cell lines DU145 and PC‐3 than AR‐positive, hormone‐sensitive prostate cancer cell lines LAPC4 and LNCaP, with minimal effect on normal prostatic epithelial and stromal cells. FKB induces apoptosis with an associated increased expression of proapoptotic proteins: death receptor‐5, Bim and Puma and a decreased expression of inhibitors of apoptosis protein: XIAP and survivin. Among them, Bim expression was significantly induced by FKB as early as 4 hr of the treatment. Knockdown of Bim expression by short‐hairpin RNAs attenuates the inhibitory effect on anchorage‐dependent and ‐independent growth and caspase cleavages induced by FKB. These findings suggest that the effect of FKB, at least in part, requires Bim expression. In addition, FKB synergizes with TRAIL for markedly enhanced induction of apoptosis. Furthermore, FKB treatment of mice bearing DU145 xenograft tumors results in tumor growth inhibition and increases Bim expression in tumor tissues. Together, these results suggest robust mechanisms for FKB induction of apoptosis preferentially for HRPC and the potential usefulness of FKB for prevention and treatment of HRPC in an adjuvant setting.
The health and economic effects of HPV DNA screening in The Netherlands
Authors: Berkhof Johannes , Coupé Veerle M. , Bogaards Johannes A. , van Kemenade Folkert J. , Helmerhorst Theo J. , Snijders Peter J. , Meijer Chris J.
Published: January 2010

We studied the health and economic effects of human papillomavirus (HPV) DNA testing in cervical screening using a simulation model. The key data source was a Dutch longitudinal screening trial. We compared cytological testing with repeat cytology (for borderline/mildly abnormal smears) to HPV testing with cytology triage (for HPV‐positive smears), combination testing (combined HPV and cytology) and cytological testing with HPV triage (for borderline/mildly abnormal smears). We varied the screening interval from 5 to 10 years. The main outcome measures were the number of cervical cancer cases, the number of quality‐adjusted life years (QALYs), and the incremental cost‐effectiveness ratio (ICER). The base‐case estimates were accompanied with ranges across 118 calibrated parameter settings (calibration criteria: cervical intraepithelial neoplasia 2/3, cancer and mortality rates). In comparison to 5‐yearly cytology, 5‐yearly HPV testing with cytology triage gave a reduction in the number of cancer cases of 23% (range, 9–27%). The reduction was 26% (range, 10–29%) for combination testing and 3% (range, −1 to 8%) for cytology with HPV triage. For strategies with primary HPV testing, the model also estimated a reduction in cancer cases when the screening interval was extended to 7.5 years. Five‐yearly cytology with HPV triage and 5 to 7.5‐yearly HPV testing with cytology triage were cost effective for the base‐case settings and the majority of calibrated parameter settings (ICER below Dutch willingness‐to‐pay threshold of €20,000/QALY). Our model indicates that HPV testing with cytology triage is likely to be cost effective. An extension of the screening interval may be considered to control costs.