bluuebunny/crossref_metadata_2025 huggingface dataset:
Activation of the neuregulin/ErbB system during physiological ventricular remodeling in pregnancy
Authors: Lemmens Katrien , Doggen Kris , De Keulenaer Gilles W.
Published: December 2010

The neuregulin-1 (NRG1)/ErbB system has emerged as a paracrine endothelium-controlled system in the heart, which preserves left ventricular (LV) performance in pathophysiological conditions. Here, we analyze the activity and function of this system in pregnancy, which imparts a physiological condition of LV hemodynamic overload. NRG1 expression and ErbB receptor activation were studied by Western blot analyses in rats and mice at different stages of pregnancy. LV performance was evaluated by transthoracic echocardiography, and myocardial performance was assessed from twitches of isolated papillary muscles. NRG1/ErbB signaling was inhibited by oral treatment of animals with the dual ErbB1/ErbB2 tyrosine kinase inhibitor lapatinib. Analyses of LV tissue revealed that protein expression of different NRG1 isoforms and levels of phosphorylated ErbB2 and ErbB4 significantly increased after 1–2 wk of pregnancy. Lapatinib prevented phosphorylation of ErbB2 and ERK1/2, but not of ErbB4 and protein kinase B (Akt), revealing that lapatinib only partially inhibited NRG1/ErbB signaling in the LV. Lapatinib did not prevent pregnancy-induced changes in LV mass and did not cause apoptotic cell death or fibrosis in the LV. Nevertheless, lapatinib led to premature maternal death of ∼25% during pregnancy and it accentuated pregnancy-induced LV dilatation, significantly reduced LV fractional shortening, and induced abnormalities of twitch relaxation (but not twitch amplitude) of isolated papillary muscles. This is the first study showing that the NRG1/ErbB system is activated, and plays a modulatory role, during physiological hemodynamic overload associated with pregnancy. Inhibiting this system during physiological overload may cause LV dysfunction in the absence of myocardial cell death.
Impact of repeated increases in shear stress via reactive hyperemia and handgrip exercise: no evidence of systematic changes in brachial artery FMD
Authors: Pyke K. E. , Jazuli F.
Published: December 2010

Reactive hyperemia (RH) creates an uncontrolled, transient increase in brachial artery (BA) shear stress (SS) for flow-mediated dilation (FMD) assessment. In contrast, handgrip exercise (HGEX) can create similar, sustained SS increases over repeated trials. The purpose of this study was to examine the impact of repeated SS elevation via RH or HGEX and the relationship between RH and HGEX %FMD. BA diameter and blood velocity were assessed with echo and Doppler ultrasound in 20 healthy subjects. Visit A consisted of four 6-min HGEX trials (HGEX trials 1–4) at the intensity required to achieve a shear rate (SR = mean blood velocity/BA diameter; an estimate of SS) of 65 s−1. Visit B consisted of four RH trials (RH trials 1–4). The RH SR area under the curve (AUC) was higher in trial 1 versus trial 3 and trial 4 ( P = 0.019 and 0.047). The HGEX mean SR was similar across trials (mean SR = 66.1 ± 5.8 s−1, P = 0.152). There were no differences in %FMD across trials or tests (RH trial 1: 6.9 ± 3.5%, trial 2: 6.9 ± 2.3%, trial 3: 7.1 ± 3.5%, and trial 4: 7.0 ± 2.8%; HGEX trial 1: 7.3 ± 3.6%, trial 2: 7.0 ± 3.6%, trial 3: 6.5 ± 3.5%, and trial 4: 6.8 ± 2.9%, P = 0.913). No relationship between subject's RH %FMD and HGEX %FMD was detected ( r2 = 0.12, P = 0.137). However, with response normalization, a relationship emerged (RH %FMD/SR AUC vs. HGEX %FMD/mean SR, r2 = 0.44, P = 0.002). In conclusion, with repeat trials, there were no systematic changes in RH or HGEX %FMD. The relationship between normalized RH and HGEX %FMD suggests that endothelial responses to different SS profiles provide related information regarding endothelial function.
Na+ channel distribution and electrophysiological heterogeneities in guinea pig ventricular wall
Authors: Osadchii Oleg E. , Soltysinska Ewa , Olesen Soren Peter
Published: December 2010

We sought to explore the distribution pattern of Na+ channels across ventricular wall, and to determine its functional correlates, in the guinea pig heart. Voltage-dependent Na+ channel (Nav) protein expression levels were measured in transmural samples of ventricular tissue by Western blotting. Isolated, perfused heart preparations were used to record monophasic action potentials and volume-conducted ECG, and to measure effective refractory periods (ERPs) and pacing thresholds, in order to assess excitability, electrical restitution kinetics, and susceptibility to stimulation-evoked tachyarrhythmias at epicardial and endocardial stimulation sites. In both ventricular chambers, Nav protein expression was higher at endocardium than epicardium, with midmyocardial layers showing intermediate expression levels. Endocardial stimulation sites showed higher excitability, as evidenced by lower pacing thresholds during regular stimulation and downward displacement of the strength-interval curve reconstructed after extrasystolic stimulation compared with epicardium. ERP restitution assessed over a wide range of pacing rates showed greater maximal slope and faster kinetics at endocardial than epicardial stimulation sites. Flecainide, a Na+ channel blocker, reduced the maximal ERP restitution slope, slowed restitution kinetics, and eliminated epicardial-to-endocardial difference in dynamics of electrical restitution. Greater excitability and steeper electrical restitution have been associated with greater arrhythmic susceptibility of endocardium than epicardium, as assessed by measuring ventricular fibrillation threshold, inducibility of tachyarrhythmias by rapid cardiac pacing, and the magnitude of stimulation-evoked repolarization alternans. In conclusion, higher Na+ channel expression levels may contribute to greater excitability, steeper electrical restitution slopes and faster restitution kinetics, and greater susceptibility to stimulation-evoked tachyarrhythmias at endocardium than epicardium in the guinea pig heart.
Cerebral microvascular rarefaction induced by whole brain radiation is reversible by systemic hypoxia in mice
Authors: Warrington Junie P. , Csiszar Anna , Johnson Daniel A. , Herman Terence S. , Ahmad Salahuddin , Lee Yong Woo , Sonntag William E.
Published: December 2010

Whole brain radiation therapy (WBRT) leads to cognitive impairment in 40–50% of brain tumor survivors following treatment. Although the etiology of cognitive deficits post-WBRT remains unclear, vascular rarefaction appears to be an important component of these impairments. In this study, we assessed the effects of WBRT on the cerebrovasculature and the effects of systemic hypoxia as a potential mechanism to reverse the microvascular rarefaction. Transgenic mice expressing green fluorescent protein driven by the Acta2 (smooth muscle actin) promoter for blood vessel visualization were randomly assigned to control or radiated groups. Animals received a clinical series of 4.5 Gy WBRT two times weekly for 4 wk followed by 1 mo of recovery. Subsequently, mice were subjected to 11% (hypoxia) or 21% (normoxia) oxygen for 1 mo. Capillary density in subregions of the hippocampus revealed profound vascular rarefaction that persisted despite local tissue hypoxia. Nevertheless, systemic hypoxia was capable of completely restoring cerebrovascular density. Thus hippocampal microvascular rarefaction post-WBRT is not capable of stimulating angiogenesis and can be reversed by chronic systemic hypoxia. Our results indicate a potential shift in sensitivity to angiogenic stimuli and/or the existence of an independent pathway of regulating cerebral microvasculature.
The hypothalamic arcuate nucleus: a new site of cardiovascular action of angiotensin-(1–12) and angiotensin II
Authors: Arakawa Hideki , Chitravanshi Vineet C. , Sapru Hreday N.
Published: December 2010

The hypothalamic arcuate nucleus (ARCN) has been reported to play a significant role in cardiovascular regulation. It has been hypothesized that the ARCN may be one of the sites of cardiovascular actions of angiotensins (ANGs). Experiments were carried out in urethane-anesthetized, artificially ventilated, adult male Wistar rats. The ARCN was identified by microinjections of N-methyl-d-aspartic acid (NMDA; 10 mM). Microinjections (50 nl) of ANG-(1–12) (1 mM) into the ARCN elicited increases in mean arterial pressure (MAP), heart rate (HR), and greater splanchnic nerve activity (GSNA). The tachycardic responses to ANG-(1–12) were attenuated by bilateral vagotomy. The cardiovascular responses elicited by ANG-(1–12) were attenuated by microinjections of ANG II type 1 receptor (AT1R) antagonists but not ANG type 2 receptor (AT2R) antagonist. Combined inhibition of ANG-converting enzyme (ACE) and chymase in the ARCN abolished ANG-(1–12)-induced responses. Microinjections of ANG II (1 mM) into the ARCN also increased MAP and HR. Inhibition of ARCN by microinjections of muscimol (1 mM) attenuated the pressor and tachycardic responses to intravenously administered ANG-(1–12) and ANG II (300 pmol/kg each). These results indicated that 1) microinjections of ANG-(1–12) into the ARCN elicited increases in MAP, HR, and GSNA; 2) HR responses were mediated via both sympathetic and vagus nerves; 3) AT1Rs, but not AT2Rs, in the ARCN mediated ANG-(1–12)-induced responses; 4) both ACE and chymase were needed to convert ANG-(1–12) to ANG II in the ARCN; and 5) ARCN plays a role in mediating the cardiovascular responses to circulating ANGs.
PKR-dependent CHOP induction limits hyperoxia-induced lung injury
Authors: Lozon Tricia I. , Eastman Alison J. , Matute-Bello Gustavo , Chen Peter , Hallstrand Teal S. , Altemeier William A.
Published: December 2010

Supplemental O2is commonly employed in patients with respiratory failure; however, hyperoxia is also a potential contributor to lung injury. In animal models, hyperoxia causes oxidative stress in the lungs, resulting in increased inflammation, edema, and permeability. We hypothesized that oxidative stress from prolonged hyperoxia leads to endoplasmic reticulum (ER) stress, resulting in activation of the unfolded protein response (UPR) and induction of CCAAT enhancer-binding protein homologous protein (CHOP), a transcription factor associated with cell death in the setting of persistent ER stress. To test this hypothesis, we exposed the mouse lung epithelial cell line MLE-12 to 95% O2for 8–24 h and evaluated for evidence of UPR induction and CHOP induction. Hyperoxia caused increased CHOP expression without other evidence of UPR activation. Because CHOP expression is preceded by phosphorylation of the α-subunit of the eukaryotic initiation factor-2 (eIF2α), we evaluated the role of double-stranded RNA-activated protein kinase (PKR), a non-UPR-associated eIF2α kinase. Hyperoxia caused PKR phosphorylation, and RNA interference knockdown of PKR attenuated hyperoxia-induced CHOP expression. In vivo, hyperoxia induced PKR phosphorylation and CHOP expression in the lungs without other biochemical evidence for ER stress. Additionally, Ddit3−/−(CHOP-null) mice had increased lung edema and permeability, indicating a previously unknown protective role for CHOP after prolonged hyperoxia. We conclude that hyperoxia increases CHOP expression via an ER stress-independent, PKR-dependent pathway and that increased CHOP expression protects against hyperoxia-induced lung injury.
Synthesis and Antimicrobial Studies of Tridentate Schiff Base Ligands with Pyrazolone Moiety and Their Metal Complexes
Authors: Jayarajan Ramasamy , Vasuki Gnanasambandam , Rao Pillutla Sambasiva
Published: December 2010

Synthesis, characterization, and antimicrobial activity of tridentate Schiffbase ligands containing pyrazolone moiety (3a and 3b) and their transition metal complexes of VO(II), Cu(II), Fe(III), and Co(II) 4a–h have been investigated. The complexes show enhanced antibacterial activity against S. aureus, E. coli, and S. typhi and antifungal activity against C. albicans, Rhizopus sp., and A. niger compared to the ligands.
New Exact Solutions for the (2 + 1)‐Dimensional Broer‐Kaup‐Kupershmidt Equations
Authors: Song Ming , Li Shaoyong , Cao Jun
Published: December 2010

We investigate the (2 + 1)‐dimensional Broer‐Kaup‐Kupershmidt equations. Some explicit expressions of solutions for the equations are obtained by using the bifurcation method and qualitative theory of dynamical systems. These solutions contain kink‐shaped solutions, blow‐up solutions, periodic blow‐up solutions, and solitary wave solutions. Some previous results are extended.
The Similarity Hypothesis and New Analytical Support on the Estimation of Horizontal Infiltration into Sand
Authors: Prevedello Celso L. , Loyola Jocely M. T.
Published: December 2010

A method based on a specific power-law relationship between the hydraulic head and the Boltzmann variable, presented using a similarity hypothesis, was recently generalized to a range of powers to satisfy the Bruce and Klute equation exactly. Here, considerations are presented on the proposed similarity assumption, and new analytical support is given to estimate the water density flux into and inside the soil, based on the concept of sorptivity and on Buckingham-Darcy's law. Results show that the new analytical solution satisfies both theories in the calculation of water density fluxes and is in agreement with experimental results of water infiltrating horizontally into sand. However, the utility of this analysis still needs to be verified for a variety of different textured soils having a diverse range of initial soil water contents.
On Clustering Impurities by Liquid Density Fluctuations
Authors: Shimkevich Alexander L.
Published: December 2010

Recent developments in liquid technology have created a new class of fluids called “nanofluids” which are two-phase mixtures of a non-metal-liquid matrix and addon particles usually less than 100 nm in size. It is reputed that such liquids have a great potential for application. Indeed, many tests have shown that their thermal conductivity can be increased by almost 20% compared to that of the base fluids for a relatively low particle loading (of 1 up to 5% in volume). It is confirmed by experimental data and simulation results. In this study, the author considers an effect of impurity clustering by liquid density fluctuations as a natural mechanism for stabilizing microstructure of the colloidal solution and estimates the effect of fractal structure of colloidal particles on thermal conductivity of water. The results of this study may be useful for motivating choosing the composition of heat-transfer suspension and developing technology for making the appropriate nanofluid.
Elevated Adiponectin Serum Levels in Women with Systemic Autoimmune Diseases
Authors: Toussirot Éric , Gaugler Béatrice , Bouhaddi Malika , Nguyen Nhu Uyen , Saas Philippe , Dumoulin Gilles
Published: December 2010

Adipose tissue produces a wide range of proteins that may influence the immune system. In this study, we assessed the serum levels of leptin, adiponectin, and ghrelin, in association with the measurements of body composition, in 15 female patients with various autoimmune diseases (systemic lupus erythematosus, primary Sjögren's syndrome, sarcoidosis, mixed connective tissue disease, vasculitis, CREST syndrome, and polymyositis) and in 15 healthy female controls. There were no statistically significant differences between the patients and controls with regard to serum leptin, serum ghrelin, global fat mass, adiposity, and fat mass in the android or gynoid regions, whereas serum adiponectin levels were higher in patients than controls ( μg/mL versus  μg/mL; ). As adiponectin is known to exhibit potent anti-inflammatory properties, a high adiponectinemia in patients with systemic autoimmune disease may mitigate the inflammatory response. However, the precise consequences of these elevated serum adiponectin levels on the metabolic syndrome development and atherosclerotic cardiovascular risk in this patient population still needs to be determined.
Strong Convergence of a New Iterative Method for Infinite Family of Generalized Equilibrium and Fixed-Point Problems of Nonexpansive Mappings in Hilbert Spaces
Authors: Wang Shenghua , Guo Baohua
Published: December 2010

We introduce an iterative algorithm for finding a common element of the set of solutions of an infinite family of equilibrium problems and the set of fixed points of a finite family of nonexpansive mappings in a Hilbert space. We prove some strong convergence theorems for the proposed iterative scheme to a fixed point of the family of nonexpansive mappings, which is the unique solution of a variational inequality. As an application, we use the result of this paper to solve a multiobjective optimization problem. Our result extends and improves the ones of Colao et al. (2008) and some others.
HDAC Activity Is Required for Efficient Core Promoter Function at the Mouse Mammary Tumor Virus Promoter
Authors: Lee Sang C. , Magklara Angeliki , Smith Catharine L.
Published: December 2010

Histone deacetylases (HDACs) have been shown to be required for basal or inducible transcription at a variety of genes by poorly understood mechanisms. We demonstrated previously that HDAC inhibition rapidly repressed transcription from the mouse mammary tumor virus (MMTV) promoter by a mechanism that does not require the binding of upstream transcription factors. In the current study, we find that HDACs work through the core promoter sequences of MMTV as well as those of several cellular genes to facilitate transcriptional initiation through deacetylation of nonhistone proteins.
Proteins with RNA Chaperone Activity: A World of Diverse Proteins with a Common Task—Impediment of RNA Misfolding
Authors: Semrad Katharina
Published: December 2010

Proteins with RNA chaperone activity are ubiquitous proteins that play important roles in cellular mechanisms. They prevent RNA from misfolding by loosening misfolded structures without ATP consumption. RNA chaperone activity is studiedin vitroandin vivousing oligonucleotide- or ribozyme-based assays. Due to their functional as well as structural diversity, a common chaperoning mechanism or universal motif has not yet been identified. A growing database of proteins with RNA chaperone activity has been established based on evaluation of chaperone activity via the described assays. Although the exact mechanism is not yet understood, it is more and more believed that disordered regions within proteins play an important role. This possible mechanism and which proteins were found to possess RNA chaperone activity are discussed here.
Reverse Genetics Modification of Cytomegalovirus Antigenicity and Immunogenicity by CD8 T‐Cell Epitope Deletion and Insertion
Authors: Lemmermann Niels A. W. , Kropp Kai A. , Seckert Christof K. , Grzimek Natascha K. A. , Reddehase Matthias J.
Published: December 2010

The advent of cloning herpesviral genomes as bacterial artificial chromosomes (BACs) has made herpesviruses accessible to bacterial genetics and has thus revolutionised their mutagenesis. This opened all possibilities of reverse genetics to ask scientific questions by introducing precisely accurate mutations into the viral genome for testing their influence on the phenotype under study or to create phenotypes of interest. Here, we report on our experience with using BAC technology for a designed modulation of viral antigenicity and immunogenicity with focus on the CD8 T‐cell response. One approach is replacing an intrinsic antigenic peptide in a viral carrier protein with a foreign antigenic sequence, a strategy that we have termed “orthotopic peptide swap”. Another approach is the functional deletion of an antigenic peptide by point mutation of its C‐terminal MHC class‐I anchor residue. We discuss the concepts and summarize recently published major scientific results obtained with immunological mutants of murine cytomegalovirus.
Possessing Heaven in Our Head: A Reformed Reading of Incarnational Ascent in Kathryn Tanner
Authors: Henreckson David P.
Published: December 2010

As recent Reformed scholarship has turned its attention to the doctrine of creation, Kathryn Tanner can be engaged as an incisive and useful interlocutor. In her book Christ the Key, Tanner advances the notion of the double movement of divine descent and incarnate ascent, an idea which intersects with current Reformed deliberations on transcendence and the “chief end” of created humanity. Tanner’s re-articulation of the discussion of nature and grace, and divine agency within creation, offers a challenging and potentially constructive contribution to Reformed dogmatics.
Secrets of Moltmann’s Tacit Tradition: Via Covenant Theology to Promise Theology
Authors: Veldman Meine
Published: December 2010

This article takes a genetic approach examining Moltmann’s early post-Reformation studies in Moyse Amyraut, Petrus Ramus, Jacob Brocard and Johann Coccejus as the secrets to the tacit tradition of his theology of hope. I contend that the gold he struck in these studies is a historical impulse and legitimization of his own turn to the horizon of the empirical and the historical. However, with respect to the dross, Moltmann critically notes that with the post-Reformation covenant theologians the word of God got entangled in a ‘system’ of hope because of their symbolic-prophetic approach to Scripture. In place of their symbolic-prophetic exegesis he substitutes a promise-exegesis as a way of pointing to God’s relationship to this world and to the human beings in it. He thus replaces the theme of a restless history, and a restless soul, with the restless promise of which God is the author, the originator and the fulfiller. In this way Moltmann found a way beyond post-reformation covenant theology and Barth’s dialectical theology, culminating in his Theology of Hope.
Reformed Thought on Freedom: Some Further Thoughts
Authors: Helm Paul
Published: December 2010

Reformed Thought on Freedom introduces philosophical apparatus that was routinely employed by Reformed Orthodox theologians for discussing the metaphysics of human action. This article first offers critical reflection on the claims made for this apparatus as providing evidence for a commitment to the freedom of indifference. Then, taking the book’s treatment of Francis Turretin’s anthropology as an example, it is argued that the claim that his view of human freedom relies on the notion of synchronic contingency is not made out. There is a failure to distinguish between indifference as an intrinsic feature of the will, and the freedom of indifference.
Physical Activity, Physical Self-Concept, and Health-Related Quality of Life of Extreme Early and Late Maturing Adolescent Girls
Authors: Cumming Sean P. , Sherar Lauren B. , Hunter Smart Joanna E. , Rodrigues Aristides M. M. , Standage Martyn , Gillison Fiona B. , Malina Robert M.
Published: December 2010

In this study we tested for differences in physical activity (PA), physical self-concept, and health-related quality of life (HRQoL) between the least and most biologically mature adolescent females within their respective chronological and academic year groups. A total of 222 British female adolescents aged 10 to 14 years ([Formula: see text] age = 12.7 years; SD = .8) completed a series of instruments assessing PA, physical self-concept, and HRQoL. Percentage of predicted adult stature was used as an index of biological maturation. A series of univariate analyses of covariance (ANCOVA), controlling for chronological age, revealed that the most mature girls within the chronological and academic year groups generally reported lower levels of physical self-concept and, to a lesser extent, PA and HRQoL when compared to the least mature girls. The findings provide partial support toward the contention that maturity-associated variance in health-related outcomes is accentuated at the extreme ends of the biological maturity continuum.
Exploiting the temperature effects on low frequency electrical spectra of sandstone: A comparison of effective diffusion path lengths
Authors: Binley Andrew , Kruschwitz Sabine , Lesmes David , Kettridge Nicholas
Published: December 2010

A number of recent investigations have highlighted the potential value of using relaxation times derived from electrical spectra to infer key physical properties of permeable rocks. To date, most studies have assumed a grain size or pore throat as a measure of the length scale of the ionic diffusive process, although this has been challenged in recent experimental investigations. We compare the electrical spectra of three sandstones, adopting a new approach in which the temperature of the rock samples is perturbed and the relaxation time measured as a function of temperature. Our results suggest that, for the sandstones tested here, the effective diffusion coefficient should be considered as a function of the electrical tortuosity. These findings may help explain the apparent long relaxation times observed in low-permeability rocks in recent experimental studies. We also highlight the need to account for temperature in related studies of electrical spectra.
An improved method for hydrofracture-induced microseismic event detection and phase picking
Authors: Song Fuxian , Kuleli H. Sadi , Toksöz M. Nafi , Ay Erkan , Zhang Haijiang
Published: December 2010

The ability to detect small microearthquakes and identify their P- and S-phase arrivals is a key issue in hydrofracture downhole monitoring because of the low signal-to-noise ratios (S/N). An array-based waveform correlation approach (matched filter) is applied to improve the detectability of small magnitude events with mechanisms and locations similar to a nearby master event. After detecting the weak events, a transformed spectrogram method is used to identify the phase arrivals. The technique has been tested on a downhole monitoring data set of the microseismic events induced by hydraulic fracturing. It is shown that, for this case, one event with a S/N around [Formula: see text], which is barely detectable using an array-stacked short-time average/long-time average (STA/LTA) detector under a reasonable false alarm rate, is readily detected on the array-stacked correlation traces. The transformed spectrogram analysis of the detected events improves P- and S-phase picking.
Kriging interpolation in seismic attribute space applied to the South Arne Field, North Sea
Authors: Hansen T. M. , Mosegaard K. , Schiøtt C. R.
Published: December 2010

Seismic attributes can be used to guide interpolation in-between and extrapolation away from well log locations using for example linear regression, neural networks, and kriging. Kriging-based estimation methods (and most other types of interpolation/extrapolation techniques) are intimately linked to distances in physical space: If two observations are located close to one another, the implicit assumption is that they are highly correlated. This may, however, not be a correct assumption as the two locations can be situated in very different geological settings. An alternative approach to the traditional kriging implementation is suggested that frees the interpolation from the restriction of the physical space. The method is a fundamentally different application of the original kriging formulation where a model of spatialvariability is replaced by a model of variability in an attribute space. To the extent that subsurface geology can be described by a set of seismic attributes, we present an automated multivariate kriging-based interpolation method that is guided by geological similarity rather than by the conventional distance measure in XYZ space. Through a case study, kriging in attribute space is used to estimate 2D porosity maps from a number of well logs and seismic attributes in the Danish North Sea. Cokriging provides uncertainty estimates that are dependent on the primary data locations in space, whereas kriging in attribute space provides uncertainty estimates that reflect subsurface geological variability. The North Sea case study demonstrates that kriging in attribute space performs better than linear regression and cokriging.
Tomographic velocity model building of the near surface with velocity-inversion interfaces: A test using the Yilmaz model
Authors: Liu Hui , Zhou Hua-wei , Liu Wenge , Li Peiming , Zou Zhihui
Published: December 2010

First-arrival traveltime tomography is a popular approach to building the near-surface velocity models for oil and gas exploration, mining, geoengineering, and environmental studies. However, the presence of velocity-inversion interfaces (VIIs), across which the overlying velocity is higher than the underlying velocity, might corrupt the tomographic solutions. This is because most first-arrival raypaths will not traverse along any VII, such as the top of a low-velocity zone. We have examined the impact of VIIs on first-arrival tomographic velocity model building of the near surface using a synthetic near-surface velocity model. This examination confirms the severe impact of VIIs on first-arrival tomography. When the source-to-receiver offset is greater than the lateral extent of the VIIs, good near-surface velocity models can still be established using a multiscale deformable-layer tomography (DLT), which uses a layer-based model parameterization and a multiscale scheme as regularization. Compared with the results from a commercial grid-based tomography, the DLT delivers much better near-surface statics solutions and less error in the images of deep reflectors.
Phase Inversion of Pickering Foam and Dry Water Stabilized by Microbowls
Authors: Nonomura Yoshimune , Ikeda Takehide , Sugimoto Masataka , Taniguchi Takashi
Published: December 2010

Microbowls, which are hollow particles with holes on their surfaces, stabilize air-in-water-type foams and water-in-air-type powders in particle/air/water ternary systems. We found a particle-dispersed state between the foam state and the powder state. Interestingly, the mixture in this new state displayed remarkable dilatational behavior, preventing the formation of foams and water droplets.
Detection of Kinase Activity Using a Synthetic System of Gold Nanoparticles in HEPES Buffer
Authors: Sawada Toshiki , Shirakawa Naoto , Hirai Yu , Hashizume Mineo , Aizawa Mamoru , Serizawa Takeshi
Published: December 2010

The reduction of tetrachloroaurate(III) ions (AuCl4−) with 2-[4-(2-hydroxyethyl)-1-piperazinyl]ethanesulfonic acid (HEPES) was used to detect protein kinase A activity. The phosphorylation of substrate peptides was identified by changes in the solution colors resulting from the aggregation of synthesized gold nanoparticles in HEPES buffer.
Efficiency and Redistribution: An Evaluative Review of Louis Kaplow's The Theory of Taxation and Public Economics
Authors: Boadway Robin
Published: December 2010

Louis Kaplow proposes a two-step methodology for normative policy analysis and illustrates it using various policy reforms. The first step is to identify efficiency gains when hypothetical lump-sum taxes can undo redistributive consequences. The second step evaluates the redistributive effects using a strictly welfaristic social welfare function. I critically review the foundations for Kaplow's procedure and its reliance on strict welfarism. I argue that basing efficiency gains on hypothetical lump-sum tax adjustments can lead to social welfare reducing policies if such tax adjustments are not carried out. I also indicate some conceptual problems with translating welfarism into policy evaluation when individuals have different utility function, and review one promising alternative approach.(JEL H20, H41, H50)
Surgery for retroperitoneal soft tissue sarcomas: aggressive re-resection of recurrent disease is possible
Authors: Lochan R , French JJ , Manas DM
Published: December 2010

INTRODUCTION

Retroperitoneal soft tissue sarcomas represent a relatively rare and complex therapeutic problem where surgery forms the mainstay of treatment and is technically demanding. In this study, we review a single UK centre’s experience with the surgical management of retro-peritoneal soft tissue sarcoma.

PATIENTS AND METHODS

We present analysis of data on patients treated between 1997 and 2006, our first 75 patients. Data collected from the Access database, included patient demographics, staging modalities, peri-operative details, treatment, outcome, pathological diagnosis and subsequent complications.

RESULTS

A total of 75 patients (M:F, 44:31) underwent 115 resectional procedures as part of the management of retroperitoneal soft-tissue sarcoma. There were 12 major complications for the 115 procedures (morbidity of 8.69%). The 30-day operative mortality was zero and the 90-day mortality rate was 1.33% (1/75). Follow-up ranged from 16–131 months. The median disease-free survival was 69 months (range, 59-78 months). Recurrences developed in 46 patients; median time to overall recurrence was 13 months (range, 3-71 months). Of these 46, 22 developed localised recurrence, which was amenable to further resection. In the cohort of patients with recurrent disease, median survival in those who underwent surgery was 53 months (range, 30–76 months) and median survival in those who did not undergo surgery was 30 months (range, 18–41 months) and this difference was statistically significant (log rank, P = 0.01).

CONCLUSIONS

Extensive resectional surgery with minimal morbidity, devoid of mortality is feasible in the treatment of retroperitoneal sarcoma. Development of recurrent disease is a significant factor influencing survival; however, localised recurrences are amenable to surgery and this can lead to improved survival.
MRSA screening in the vascular day-case population
Authors: Ahmad Y , Khandelwal S , Nicolson AM , Simms MH
Published: December 2010

INTRODUCTION

The UK Government has prioritised methicillin-resistant Staphylococcus aureus (MRSA) screening and new operational guidance has instructed that all day-case surgical patients should be screened from April 2009. We sought to identify the number of MRSA-positive patients in the vascular day-case population over a 1-year period and to profile this cohort in terms of risk-factors for MRSA. We also sought to identify whether the new guidance from the Department of Health (DH) had resulted in increased screening rates.

PATIENTS AND METHODS

Electronic records and laboratory culture results were prospectively consulted to identify whether patients had been screened and if MRSA had been isolated. Consideration was given to whether any patients had a delayed discharge or subsequent admission with an MRSA-related complication.

RESULTS

Six patients (2.1%) screened MRSA-positive (DH estimate 7%); five were previously known to be MRSA-positive, therefore only 0.36% patients were newly-identified as MRSA-positive. The proportion of patients screened increased from 35% to 72.5% after April 2009, in accordance with DH guidance. Successful decolonisation was proved in two patients (33.3%).

CONCLUSIONS

There is dispute with several of the key assumptions behind the DH’s impact assessment justifying an expanded MRSA-screening policy. It is not cost-effective to screen all vascular day-case admissions. We recommend selective screening for patients previously identified as MRSA-positive, or considered high risk.
How does the media profile of cancer compare with prevalence?
Authors: Williamson JML , Jones IH , Hocken DB
Published: December 2010

INTRODUCTION

Knowledge and understanding of disease can influence time to presentation and potentially, therefore, cancer survival rates. The media is one of the most important sources of public health information and it influences the awareness and perception of cancer. It is not known if the reportage of cancer by the media is representative to the true incidence of disease.

MATERIALS AND METHODS

The top 10 UK daily newspapers were assessed over a 1-year period for the 10 most common UK cancers via their on-line search facilities.

RESULTS

Of the 5832 articles identified, there was marked over-representation of breast, kidney and stomach cancer with ratios of prevalence to reporting of 1.4, 1.9 and 3.2 to 1, respectively. Colorectal, non-Hodgkin lymphoma, bladder and oesophageal cancers are all markedly under-represented with ratios of 0.4, 0.2, 0.6 and 0.4 to 1, respectively.

CONCLUSIONS

A policy of media advocacy by health professionals could enhance the information provided by the media and thus reflect the true extent of disease. A partnership between health professionals and journalists could result in articles that are relevant to the population, informative and in a style and format that is easily comprehendible. Targeted public health information could highlight the ‘red-flag’ symptoms and break down any stigma associated with cancer. This enhanced awareness could improve the health-seeking behaviour of the general population and reduce the delay from symptoms to diagnosis.
The difficult ureter: what is the incidence of pre-stenting?
Authors: Cetti RJ , Biers S , Keoghane SR
Published: December 2010

INTRODUCTION

Difficulty may be encountered with retrograde access for rigid and flexible ureterorenoscopy (URS) due to anatomic abnormalities, a narrow ureteric lumen, tortuous ureteric path or previous instrumentation. Ureteric dilatation using a balloon or tapered dilator can occasionally fail and will usually lead to the placement of a ureteric stent. We present our experience and incidence of pre-stenting after failed standard access and dilatation techniques, the aim being to quote a figure for the patient at the time of consent.

PATIENTS AND METHODS

Data were collected prospectively from a single surgeon at a regional tertiary referral stone unit. The outcomes of those patients pre-stented, for failed access, were recorded.

RESULTS

Between December 2007 and December 2008, a total of 119 patients underwent flexible and rigid URS. Mean patient age was 49 years (range, 19–86 years). Of these, 107 cases were undertaken for urolithiasis and 12 cases for diagnosis of upper tract malignancy. 12% (13/107) of cases were for pain and non-diagnostic imaging and 8.4% (9/107) of patients were pre-stented because of failed access, without complication, and subsequently had successful interval treatment. Of the remaining successful cases of confirmed urolithiasis, 33% (28/85) and 67% (56/85) were undertaken for ureteric and renal calculi, respectively. Stone clearance rates were 83% (19/23) and 75% (3/4) for lower pole renal calculi 5–10 mm and > 10 mm in size, respectively. The overall clearance rate for lower pole calculi was 81% (22/27). The ureteric stone clearance rate was 86% (24/28) rising to 92% (24/26) in those solitary stones less than 10 mm in size.

CONCLUSIONS

The incidence of ureteric pre-stenting in a tertiary referral unit was 8% and should be considered and indeed discussed with patients when obtaining pre-operative consent, especially for purely elective, non-urgent, upper tract cases. The alternative for these difficult, tight ureters is extensive balloon dilatation, with the risk of trauma and the potential for long-term stricture formation.
‘An interventional urology list’ – a novel concept for UK urological services
Authors: Masood Junaid , Ismail Mohamed , El-Husseiny Tamer , Moraitis Konstantinos , Albanis Stephanos , Papatsoris Athanasios , Buchholz Noor
Published: December 2010

INTRODUCTION

Almost all patients in the UK with obstructed and/or infected kidneys are referred to interventional radiology for percutaneous nephrostomy and/or placement of an anterograde JJ stent. Although this ‘tradition’ is going strong in the UK, urologists throughout the world have evolved their practice to encompass such interventional procedures in their remit. We have set up a local anaesthetic list ‘interventional urology list’ in our ESWL suite. We present our 4-year experience and discuss the benefits that this interventional list brings to our patients, our trainees, our interventional radiology colleagues and to the hospital trust.

PATIENTS AND METHODS

From May 2005 to May 2009, we have been running this list, twice-weekly, performing procedures such as nephrostomies, anterograde stents, nephrostograms and stent exchanges all under local anaesthetic.

RESULTS

A total of 580 procedures have been carried out on this list over this period. Our success rate for nephrostomy insertion is 96% with three failures, as a result of patient discomfort. No major complications and three minor complications were reported. We had four failed anterograde stenting procedures (out of 80). All other procedures including nephrostograms, stent exchanges/removals/insertions, as well as renal cyst aspiration and sclerotisation were successfully carried out.

CONCLUSIONS

Our results of percutaneous nephrostomy and antegrade stenting are favourable when compared with published data on nephrostomies. This novel set up has resulted in several improvements to the service we offer patients and also provided significant improvement in training for our residents. We encourage other departments to try and develop this type of ‘interventional urology list’.
The role of temporal artery biopsies in giant cell arteritis
Authors: Davies CG , May DJ
Published: December 2010

A knowledge of the disease process of giant cell arteritis and its diagnosis can help a surgeon to decide which patients will benefit from a biopsy being performed and identify where a biopsy would be of no value in their management. This article discusses the issues involved.
Establishing pneumoperitoneum: Verres or Hasson? The debate continues
Authors: Dunne N , Booth MI , Dehn TCB
Published: December 2010

INTRODUCTION

The technique of establishing pneumoperitoneum for laparoscopic surgery remains contentious, with various different techniques available and each having its own advocates. The Verres needle approach has attracted much criticism and is seen to entail more risk, but is this view justified in the era of evidence-based medicine?

PATIENTS AND METHODS

Over a 6-year period, a prospective study was undertaken of 3126 patients who underwent laparoscopic surgery performed by two upper gastrointestinal surgeons. One surgeon preferred the Verres needle and the other an open technique. A database was created of all cases and complication rates of the different techniques ascertained.

RESULTS

Peri-umbilical Verres needle was used in 1887 cases (60.4%) with two complications encountered, both of which were colonic injuries, with an incidence of 0.1%. Open port insertion was used in 1200 cases (38.4%) with one complication, a small bowel perforation, to give an incidence of 0.08%. The Verres needle was used in alternative positions in 22 cases (0.75%) and, when used in the left upper quadrant (19 cases), there was one complication, a left hepatic lobe puncture, with an incidence of 5.26%. Our overall incidence of intra-abdominal injury was 0.13%, all in patients who had undergone previous abdominal surgery, and in the subgroup of patients with previous surgery the rate was 0.78%. There was no mortality.

CONCLUSIONS

Practice varies as to the method chosen to induce pneumoperitoneum, but our results show there is no significant difference between the technique chosen and incidence of complications, and this is supported in the literature.
Party Conferences 2010 – Laying the Foundations for the Year Ahead
Authors: Stebbing Richard
Published: December 2010

With a general election, a historic coalition government and a forthcoming white paper on NHS reforms, this year was an exceptionally important and busy party conference season for the College.
Effect of the Human Tissue Act on UK Orthopaedic Cadaveric Research
Authors: Heasley R , Farrow L , Ahmad F , Lovell M
Published: December 2010

Following public inquiries into the events of Bristol Royal Infirmary (www.bristol-inquiry.org.uk) and Royal Liverpool Children's Hospital (www.rlcinquiry.org.uk) the laws on the use of organs and tissue were reviewed. The UK Human Tissue Act 2004 was fully implemented in September 2006, replacing the Human Tissue Act 1961, the Anatomy Act 1984 and the Human Organ Transplants Act 1989. These reports highlighted the significant disparity between public opinion and medical professionals on issues of consent regarding human tissue.
Spectrophotometric Determination of Iron in Pharmaceutical and Water Samples by Interacting with 5-(4-Nitrophenylazo) Salicylic Acid and Eosin
Authors: Hashem E. Y. , Seleim M. M. , El-Zohry Ahmed M.
Published: December 2010

A highly stable ternary complex of iron(III) with 5-(4-nitrophenylazo) salicylic acid (NPAS) and Eosin (Es) in acidic medium at room temperature gave a maximum absorption at 545 nm with a molar absorptivity 2.81×104 L mol−1 cm−1. A spectrophotometric method using these ligands was developed and optimized in terms of pH, stability of the complex, amount of reagent required, sensitivity, linearity, and the effect of various foreign ions was studied. The linear range for iron(III) determination is 0.18–6.0 mg L−1. The method was sensitive, accurate, and all the reagents were stable under the working conditions. Moreover, the method was easy to perform for the determination of iron in pharmaceutical and water samples.
Intrauterine Effects of Maternal Prepregnancy Overweight on Child Cognition and Behavior in 2 Cohorts
Authors: Brion Marie-Jo , Zeegers Mijke , Jaddoe Vincent , Verhulst Frank , Tiemeier Henning , Lawlor Debbie A. , Smith George Davey
Published: December 2010

OBJECTIVE:

Greater maternal prepregnancy adiposity has been associated with behavioral problems, such as attention-deficit/hyperactivity disorder, and lower intellectual function in offspring. However, few studies of humans have explored this, and it is unclear if intrauterine mechanisms or confounding factors drive these associations.

PATIENTS AND METHODS:

Parental adiposity and offspring verbal skills, nonverbal skills, and behavioral problems were assessed in the British Avon Longitudinal Study of Parents and Children (N = ∼5000) and Dutch Generation R (N = ∼2500) cohorts. We aimed to determine the plausibility of intrauterine effects by (1) adjusting for multiple confounders, (2) comparing associations between maternal and paternal overweight with offspring cognition/behaviors, and (3) searching for cross-cohort consistency.

RESULTS:

Maternal prepregnancy overweight was associated with reduced child verbal skills (unadjusted). However, after adjusting for confounders, this result was not consistently observed in both cohorts. Maternal overweight was also associated with child total behavior problems and externalizing problems even after adjusting for confounders. However, this was observed in Generation R only and was not replicated in the British Avon Longitudinal Study of Parents and Children. No associations of maternal overweight with child attention problems, emotional/internalizing problems, or nonverbal skills were observed in either cohort. Paternal overweight was not associated with any of the child outcomes but was also less strongly related to potential confounding factors than was maternal overweight.

CONCLUSIONS:

Overall, we found little consistent evidence of intrauterine effects of maternal prepregnancy overweight on child cognition and behavior. Some associations initially observed were not consistently replicated across cohorts or robust to adjustment for confounding factors and, thus, are likely to reflect confounding by socioeconomic or postnatal factors.