bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Phase II dose ranging, double‐blind, placebo‐controlled study of alicaforsen enema in subjects with acute exacerbation of mild to moderate left‐sided ulcerative colitis
Authors: VAN DEVENTER S. J. H. , WEDEL M. K. , BAKER B. F. , XIA S. , CHUANG E. , MINER P. B. 
Published: April 2006

SummaryBackgroundAlicaforsen is an antisense oligonucleotide designed to inhibit expression of human intercellular adhesion molecule 1. Previous clinical studies have demonstrated activity of alicaforsen enema in ulcerative colitis and pouchitis.AimTo determine the minimally effective dosing regimen of alicaforsen enema in subjects with mild to moderate left‐sided ulcerative colitis.MethodsRandomized, placebo‐controlled, double‐blind, two‐dose ranging multicentre study. One hundred and twelve subjects were equally randomized to receive one of four alicaforsen enema regimens or placebo daily for 6 weeks. Primary end point was Disease Activity Index at week 6. Secondary end points included evaluation of clinical improvement, relapse rates and durability of response. Analysis of data were performed on the intent‐to‐treat population.ResultsNo significant difference was observed between treatment arms and placebo in the primary end point. A prolonged reduction in mean% Disease Activity Index relative to baseline was observed in the daily 240 mg alicaforsen enema treatment arm in comparison with placebo from week 18 (51% vs. 18%, P = 0.04) to week 30 (50% vs. 11%, P = 0.03).ConclusionsAlicaforsen enema was safe and well tolerated at all doses studied. The durability of the response to alicaforsen enema treatment may suggests a disease‐modifying effect.
Sub‐optimal proton pump inhibitor dosing is prevalent in patients with poorly controlled gastro‐oesophageal reflux disease
Authors: GUNARATNAM N. T. , JESSUP T. P. , INADOMI J. , LASCEWSKI D. P. 
Published: April 2006

SummaryBackgroundProton pump inhibitors are the most potent drug treatment for gastro‐oesophageal reflux disease. Premeal dosing maximizes efficacy while sub‐optimal dose timing may limit efficacy.AimTo determine the prevalence of sub‐optimal proton pump inhibitor dosing in a community‐based gastro‐oesophageal reflux disease population.Materials and methodsOne hundred patients on proton pump inhibitors referred for persistent gastro‐oesophageal reflux disease symptoms were questioned about their proton pump inhibitor dosing habits and classified as optimal or sub‐optimal dosers. Optimal dosers took proton pump inhibitors with or up to 60 min before meals. Sub‐optimal dosers took proton pump inhibitors >60 min before meals, after meals, as needed, or at bedtime.ResultsForty‐six percent dosed optimally. Fifty‐four percent dosed sub‐optimally with 21 of 54 (39%) dosing >60 min before meals, 16 (30%) after meals, 15 (28%) at bedtime and two (4%) as needed. Only 6% of the subjects on once‐daily proton pump inhibitor regimens and 33% of subjects taking proton pump inhibitors two‐ to three times daily dosed in a manner that maximized acid suppression (15–30 min before a meal).ConclusionsIn this study, 54% of patients dosed proton pump inhibitors sub‐optimally and only 12% dosed in a manner that maximized acid suppression. As sub‐optimal proton pump inhibitor dose timing can limit efficacy, patients with refractory symptoms should be asked about dose timing to avoid inappropriate and costly dose escalations.
Increased intestinal permeability and NOD2 variants in familial and sporadic Crohn's disease
Authors: D'INCÀ R. , ANNESE V. , DI LEO V. , LATIANO A. , QUAINO V. , ABAZIA C. , VETTORATO M. G. , STURNIOLO G. C. 
Published: April 2006

SummaryBackgroundAbnormal barrier function may be genetically determined in Crohn's disease.AimTo examine the role of abnormal intestinal permeability in genetic predisposition in multiplex vs. sporadic Crohn's disease families.MethodsIntestinal permeability was measured in patients, relatives and partners by means of lactulose/mannitol test. Healthy subjects from the hospital staff served as controls. CARD15 mutations were investigated in sporadic and familial Crohn's disease patients and in a group of blood donors.ResultsThe median lactulose/mannitol ratio was increased significantly in Crohn's disease patients vs. their relatives [0.03 (0.01–0.24) vs. 0.01 (0.003–0.19), P = 0.005]. The percentage of abnormal tests was significantly higher in familial vs. sporadic first‐degree relatives of Crohn's disease patients (29% vs. 11%, P = 0.0281). Abnormal permeability occurred significantly more frequent in patients with familial Crohn's disease carrying the frameshift mutation. The frameshift mutation 3020insC was associated with increased permeability in 75% in the multiplex and in 61% of the sporadic CD patients. One partner had abnormal lactulose/mannitol ratio.ConclusionIntestinal permeability is raised in Crohn's disease patients and relatives, with higher rates in familial vs. sporadic healthy relatives. CARD15 mutations are associated with abnormal permeability in ileal Crohn's disease.
Systemic eosinophil response induced by respiratory syncytial virus
Authors: Lindemans C A , Kimpen J L L , Luijk B , Heidema J , Kanters D , Van Der Ent C K , Koenderman L 
Published: April 2006

SummaryRespiratory syncytial virus (RSV) is a common cause of lower respiratory tract disease (LRTD) in infants. Eosinophils have been suggested to play a role in the disease pathogenesis of LRTD. Inflammation can induce functional and morphological alterations of peripheral blood granulocytes. In patients with RSV LRTD, we aimed to investigate the eosinophil activation status by analysing surface markers. In vitro stimulation of eosinophils with cytokines leads to up-regulation of CD11b and priming markers recognized by the recently developed priming markers A17 and A27, whereas interleukin (IL)-5Rα is being down-regulated. In 51 patients and 10 controls we examined the expression of these surface markers on eosinophils in moderate to severe RSV-induced LRTD patients at the time of admission and 6 weeks later during the convalescence phase. RSV-patients were characterized by a higher eosinophil CD11b expression compared to controls. Although basal A17 and A27 expression was not increased, we observed a significantly higher expression of these priming epitopes on N-formyl-methionyl-leucyl-phenylalanine (fMLP)-stimulated cells of RSV patients compared with cells of controls, indicative of prior in vivo priming. Furthermore, IL-5Rα expression was down-regulated on peripheral blood eosinophils of these patients. Follow-up blood samples showed normalization of all markers but CD11b, which was persistently increased. Utilizing cellular markers, we observed that peripheral blood eosinophils from infants with RSV LRTD are in a more activated state compared to eosinophils of controls, which normalizes only partially during convalescence.
Polyclonal expansion of large granular lymphocytes in common variable immunodeficiency − association with neutropenia
Authors: Holm A M , Tjønnfjord G , Yndestad A , Beiske K , Müller F , Aukrust P , Frøland S S 
Published: April 2006

SummaryCommon variable immunodeficiency (CVID) is the most frequent symptomatic primary immunodeficiency disease, characterized by low levels of circulating immunoglobulins and recurrent bacterial infections, particularly of the respiratory tract. T cell dysfunction is often present, and lymphoproliferative and autoimmune disorders as well as haematological cytopenias are frequently observed. In this study, we report a polyclonal expansion of large granular lymphocytes (LGL) in a substantial proportion of CVID patients, associated with splenomegaly, increased numbers of CD8+ T cells, inverted CD4 : CD8 T cell ratios and neutropenia. CVID patients who had both increased numbers of LGL and granulocytopenia had elevated levels of soluble Fas ligand (sFasL). Our observations indicate that CVID may be added to the list of inflammatory diseases associated with increased numbers of LGL. Furthermore, our findings suggest common pathogenic mechanisms of granulocytopenia in CVID and lymphoproliferative disease of granular lymphocytes.
The relationship between the first Fresnel zone and the normalized geometrical spreading factor1
Authors: Sun Jianguo 
Published: April 2006

AbstractConventionally, the Fresnel zone and the geometrical spreading factor are investigated separately, because they belong to different theories of wave propagation. However, if the paraxial ray method is used for establishing the Fresnel–Kirchhoff diffraction formula for a laterally inhomogeneous multilayered medium, it can be shown that the normalized geometrical spreading factor is inversely proportional to the area of the first Fresnel zone associated with the reflection point. Therefore, if no diffracting edge cuts the first Fresnel zone, the geometrical optics approximation represents the principal part of the wavefield obtained by Fresnel–Kirchhoff diffraction theory. Otherwise, the geometrical optics approximation has to be corrected by adding edge diffractions. It is also shown that Kirchhoff‐type migration and geometrical spreading factor correction both reduce the first Fresnel zone to a zone with unit area.
Practical techniques for 3D resistivity surveys and data inversion1
Authors: Loke M.H. , Barker R.D. 
Published: April 2006

AbstractTechniques to reduce the time needed to carry out 3D resistivity surveys with a moderate number (25 to 100) of electrodes and the computing time required to interpret the data have been developed. The electrodes in a 3D survey are normally arranged in a square grid and the pole‐pole array is used to make the potential measurements. The number of measurements required can be reduced to about one‐third of the maximum possible number without seriously degrading the resolution of the resulting inversion model by making measurements along the horizontal, vertical and 45° diagonal rows of electrodes passing through the current electrode. The smoothness‐constrained least‐squares inversion method is used for the data interpretation. The computing time required by this technique can be greatly reduced by using a homogeneous half‐space as the starting model so that the Jacobian matrix of partial derivatives can be calculated analytically. A quasi‐Newton updating method is then used to estimate the partial derivatives for subsequent iterations. This inversion technique has been tested on synthetic and field data where a satisfactory model is obtained using a modest amount of computer time. On an 80486DX2/66 microcomputer, it takes about 20 minutes to invert the data from a 7 by 7 electrode survey grid. using the techniques described below, 3D resistivity surveys and data inversion can be carried out using commercially available field equipment and an inexpensive microcomputer.
The magnetotelluric response over 2D media with resistivity frequency dispersion1
Authors: Mauriello P. , Patella D. , Siniscalchi A. 
Published: April 2006

AbstractWe investigate the magnetotelluric response of two‐dimensional bodies, characterized by the presence of low‐frequency dispersion phenomena of the electrical parameters. The Cole‐Cole dispersion model is assumed to represent the frequency dependence of the ‘impedivity’ complex function, defined as the inverse of Stoyer's ‘admittivity’ complex parameter. To simulate real geological situations, we consider three structural models, representing a sedimentary basin, a geothermal system and a magma chamber, assumed to be partially or totally dispersive. From a detailed study of the frequency and space behaviours of the magnetotelluric parameters, taking known non‐dispersive results as reference, we outline the main peculiarities of the local distortion effects, caused by the presence of dispersion in the target media. Finally, we discuss the interpretative errors which can be made by neglecting the dispersion phenomena. The apparent dispersion function, which was defined in a previous paper to describe similar effects in the one‐dimensional case, is again used as a reliable indicator of location, shape and spatial extent of the dispersive bodies. The general result of this study is a marked improvement in the resolution power of the magnetotelluric method.
Estimation of multivalued arrivals in 3D models using wavefront construction—Part I1
Authors: Vinje V. , Iversen E. , Åstebøl K. , Gjøystdal H. 
Published: April 2006

AbstractA new 3D wavefield modelling approach based on dynamic ray tracing is presented. This approach is called wavefront construction, and it can be used in 3D models with constant or smoothly varying material properties (S‐ and P‐velocity and density) separated by smooth interfaces. Wavefronts consisting of rays arranged in a triangular network are propagated stepwise through the model. At each time step, the differences in a number of parameters are checked between each pair of rays on the wavefront. New rays are interpolated whenever this difference between pairs of rays exceeds some predefined maximum value. A controlled sampling of the wavefront at all time steps is thus obtained. Receivers are given multiple‐event values by interpolation when the wavefronts pass them. The strength of the wavefront construction method is that it is robust and efficient.
Part II: Tracing and interpolation1
Authors: Vinje V. , Iversen E. , Åstebøl K. , Gjøystdal H. 
Published: April 2006

AbstractThe numerical tracing of short ray segments and interpolation of new rays between these ray segments are central constituents of the wavefront construction method. In this paper the details of the ray tracing and ray‐interpolation procedures are described. The ray‐tracing procedure is based on classical ray theory (high‐frequency approximation) and it is both accurate and efficient. It is able to compute both kinematic and dynamic parameters at the endpoint of the ray segments, given the same set of parameters at the starting point of the ray. Taylor series are used to approximate the raypath so that the kinematic parameters (new position and new ray tangent) may be found, while a staggered finite‐difference approximation gives the dynamic parameters (geometrical spreading).When divergence occurs in some parts of the wavefront, new rays are interpolated. The interpolation procedure uses the kinematic and dynamic parameters of two parent rays to estimate the initial parameters of a new ray on the wavefront between the two rays. Third‐order (cubic) interpolation is used for interpolation of position, ray tangent and take‐off vector from the source) while linear interpolation is used for the geometrical spreading parameters.
Shallow velocity–depth model imaging by refraction tomography1
Authors: Belfer Igor , Landa Evgeny 
Published: April 2006

AbstractA tomographic imaging technique combined with coherence inversion is proposed for constructing a near‐surface model from refraction events. A model obtained from coherence inversion serves as a good background model for the tomographic reconstruction. A simultaneous iterative reconstruction technique (SIRT) algorithm was used for this purpose. This is a simple algorithm and can be easily adapted to irregular acquisition geometry and limited angular aperture. Using synthetic data it was shown that the proposed procedure can be used for determination of local velocity anomalies in a shallow subsurface. The technique was also tested on a real data set.
A case example of near‐surface correction for multicomponent VSPS
Authors: Zeng Xinwu , MacBeth Colin 
Published: April 2006

AbstractA deterministic near‐surface correction procedure is developed for multicomponent VSP data, shot using directional sources and recorded using three‐component receivers. The method is capable of removing unwanted effects of acquisition such as unequal source strengths or misorientations, but may also remove near‐surface multiples and anisotropy. This is of considerable benefit for obtaining accurate and consistent estimates of subsurface anisotropy from different source combinations. Application of the technique is illustrated using a dataset from the Romashkino reservoir in Russia, where three or four different directional sources are used at the same source locations. The technique corrects for the large discrepancies which exist between the estimates obtained using different source combinations. Application of the technique to three wells in the survey region reveals a nearly isotropic subsurface, except for a few isolated zones of moderate to high (2 to 8%) anisotropy which lie close to the expected depth for the reservoir. Although there is no significant correlation with the production figures for each well, the qS1 polarization azimuth within the reservoir does vary at each well location, suggesting that this may be a more sensitive indicator of reservoir Drocess.
A few case histories of subsurface imaging with EMAP as an aid to seismic processing and interpretation1
Authors: Warren Roy K. 
Published: April 2006

AbstractThe electromagnetic array profiling (EMAP) exploration method can be combined with a direct one‐dimensional inversion process for conversion to depth to produce a subsurface resistivity cross‐section. This cross‐section may then be interpreted in parallel with a seismic cross‐section to enhance the prediction of rock type and structure. In complex thrust environments and areas of shallow carbonate rocks, the EMAP method is often used to provide additional data either to help the seismic processor and/or to aid the seismic interpretation. In particular, the electromagnetic (EM) data can be used to build an independent seismic velocity file for depth migration.Three EMAP test areas in the western United States are used to demonstrate such a use of EMAP as an expioration tool. The first shows how a velocity file is estimated from resistivity data for seismic depth migration processing in a complex thrust environment. In the second example, the method is applied in layer‐cake geology with high seismic velocity rocks at the earth's surface. The third example is another complex thrust environment, but in this case the velocity file derived from the resistivity data is used for stacking the seismic data.
Electromagnetic mapping of electrical conductivity beneath the Columbia basalts1
Authors: Morrison H. Frank , Shoham Yoram , Hoversten G. Michael , Torres‐Verdín Carlos 
Published: April 2006

AbstractSedimentary rocks beneath the Columbia River Basalt Group are recognized as having potential for oil and gas production, but the overlying layered basalts effectively mask seismic reflections from the underlying sediments. Four electromagnetic (EM) methods have been applied on profiles crossing Boylston Ridge, a typical east–west trending anticline of the Yakima Fold Belt, in an attempt to map the resistivity interface between the basalts and the sediments and to map variations in structure and resistivity within the sediments. The EM surveys detected strong variations in resistivity within the basalts, and in particular the continuous magnetotelluric array profiling (EMAP) revealed resistivity lows beneath the surface anticlines. These low resistivity zones probably coincide with fracturing in the core of the anticlines and they appear to correlate well with similar zones of low seismic velocity observed on a nearby seismic profile.The controlled‐source EM surveys (in‐loop transient, long‐offset transient, and variable‐offset frequency‐domain) were designed in anticipation of relatively uniform high resistivity basalts, and were found to have been seriously distorted by the intrabasalt conductors discovered in the field. In particular, the resistivity sections derived from 1D inversions were found to be inconsistent and misleading. The EMAP survey provided the most information about the subsurface resistivity distribution, and was certainly the most cost‐effective. However, both controlled‐source and EMAP surveys call for accurate 2D or 3D inversion to accommodate the geological objectives of this project.
Transient electromagnetic vs. seismic prospecting—a correspondence principle1
Authors: de Hoop Adrianus T. 
Published: April 2006

AbstractA correspondence principle is derived that relates the Green's functions (point‐receiver responses to point‐source excitations) for 2D transient diffusive electro‐magnetic fields with electric field in the vertical plane to 2D seismic waves (in the acoustic approximation) with particle velocity in the vertical plane in arbitrarily inhomogeneous media. The constituent medium parameters in the two cases are related via two global proportionality constants. The kernels in the integral operators that express the diffusion phenomenon in terms of the wave phenomenon are of a smoothing nature. The fact that they are explicitly known can be of importance to the inverse operation. The correspondence principle is the fundamental tool in comparing the spatial resolving powers in the two methods of geophysical prospecting.
Integrating long‐offset transient electromagnetics (LOTEM) with seismics in an exploration environment1
Authors: Strack K.‐M. , Vozoff K. 
Published: April 2006

AbstractThe applications of electromagnetics have increased in the past two decades because of an improved understanding of the methods, improved service availability, and the increased focus of exploration in the more complex reservoir characterization issues. For electromagnetic methods surface applications for hydrocarbon Exploration and Production are still a special case, while applications in borehole and airborne research and for engineering and environmental objectives are routine.In the past, electromagnetic techniques, in particular deep transient electromagnetics, made up a completely different discipline in geophysics, although many of the principles are similar to the seismic one. With an understanding of the specific problems related to data processing initially and then acquisition, the inclusion of principles learned from seismics happened almost naturally. Initially, the data processing was very similar to seismic full‐waveform processing. The hardware was also changed to include multichannel acquisition systems, and the field procedures became very similar to seismic surveying. As a consequence, the integration and synergism of the interpretation process is becoming almost automatic.The long‐offset transient electromagnetic (LOTEM) technique will be summarized from the viewpoint of its similarity to seismics. The complete concept of the method will also be reviewed. An interpretation case history that integrates seismic and LOTEM from a hydrocarbon area in China clearly demonstrates the limitations and benefits of the method.