bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Fusion Inhibitor Prevents Spread of Immunodeficiency Viruses, but Not Activation of Virus-Specific T Cells, by Dendritic Cells
Authors: Frank I. , Stössel H. , Gettie A. , Turville S. G. , Bess J. W. , Lifson J. D. , Sivin I. , Romani N. , Robbiani M. 
Published: March 2008

ABSTRACTDendritic cells (DCs) play a key role in innate immune responses, and their interactions with T cells are critical for the induction of adaptive immunity. However, immunodeficiency viruses are efficiently captured by DCs and can be transmitted to and amplified in CD4+T cells, with potentially deleterious effects on the induction of immune responses. In DC-T-cell cocultures, contact with CD4+, not CD8+, T cells preferentially facilitated virus movement to and release at immature and mature DC-T-cell contact sites. This occurred within 5 min of DC-T-cell contact. While the fusion inhibitor T-1249 did not prevent virus capture by DCs or the release of viruses at the DC-T-cell contact points, it readily blocked virus transfer to and amplification in CD4+T cells. Higher doses of T-1249 were needed to block the more robust replication driven by mature DCs. Virus accumulated in DCs within T-1249-treated cocultures but these DCs were actually less infectious than DCs isolated from untreated cocultures. Importantly, T-1249 did not interfere with the stimulation of virus-specific CD4+and CD8+T-cell responses when present during virus-loading of DCs or for the time of the DC-T-cell coculture. These results provide clues to identifying strategies to prevent DC-driven virus amplification in CD4+T cells while maintaining virus-specific immunity, an objective critical in the development of microbicides and therapeutic vaccines.
MicroRNA-155 Is an Epstein-Barr Virus-Induced Gene That Modulates Epstein-Barr Virus-Regulated Gene Expression Pathways
Authors: Yin Qinyan , McBride Jane , Fewell Claire , Lacey Michelle , Wang Xia , Lin Zhen , Cameron Jennifer , Flemington Erik K. 
Published: March 2008

ABSTRACT
The cellular microRNA miR-155 has been shown to be involved in lymphocyte activation and is expressed in Epstein-Barr virus (EBV)-infected cells displaying type III latency gene expression but not type I latency gene expression. We show here that the elevated levels of miR-155 in type III latency cells is due to EBV gene expression and not epigenetic differences in cell lines tested, and we show that expression in EBV-infected cells requires a conserved AP-1 element in the miR-155 promoter. Gene expression analysis was carried out in a type I latency cell line transduced with an miR-155-expressing retrovirus. This analysis identified both miR-155-suppressed and -induced cellular mRNAs and suggested that in addition to direct targeting of 3′ untranslated regions (UTRs), miR-155 alters gene expression in part through the alteration of signal transduction pathways. 3′ UTR reporter analysis of predicted miR-155 target genes identified the transcriptional regulatory genes encoding BACH1, ZIC3, HIVEP2, CEBPB, ZNF652, ARID2, and SMAD5 as miR-155 targets. Western blot analysis of the most highly suppressed of these, BACH1, showed lower expression in cells transduced with a miR-155 retrovirus. Inspection of the promoters from genes regulated in EBV-infected cells and in cells infected with an miR-155 retrovirus identified potential binding sequences for BACH1 and ZIC3. Together, these experiments suggest that the induction of miR-155 by EBV contributes to EBV-mediated signaling in part through the modulation of transcriptional regulatory factors.
Arrangement of L2 within the Papillomavirus Capsid
Authors: Buck Christopher B. , Cheng Naiqian , Thompson Cynthia D. , Lowy Douglas R. , Steven Alasdair C. , Schiller John T. , Trus Benes L. 
Published: March 2008

ABSTRACT
Papillomaviruses are a family of nonenveloped DNA tumor viruses. Some sexually transmitted human papillomavirus (HPV) types, including HPV type 16 (HPV16), cause cancer of the uterine cervix. Papillomaviruses encode two capsid proteins, L1 and L2. The major capsid protein, L1, can assemble spontaneously into a 72-pentamer icosahedral structure that closely resembles native virions. Although the minor capsid protein, L2, is not required for capsid formation, it is thought to participate in encapsidation of the viral genome and plays a number of essential roles in the viral infectious entry pathway. The abundance of L2 and its arrangement within the virion remain unclear. To address these questions, we developed methods for serial propagation of infectious HPV16 capsids (pseudoviruses) in cultured human cell lines. Biochemical analysis of capsid preparations produced using various methods showed that up to 72 molecules of L2 can be incorporated per capsid. Cryoelectron microscopy and image reconstruction analysis of purified capsids revealed an icosahedrally ordered L2-specific density beneath the axial lumen of each L1 capsomer. The relatively close proximity of these L2 density buttons to one another raised the possibility of homotypic L2 interactions within assembled virions. The concept that the N and C termini of neighboring L2 molecules can be closely apposed within the capsid was supported using bimolecular fluorescence complementation or “split GFP” technology. This structural information should facilitate investigation of L2 function during the assembly and entry phases of the papillomavirus life cycle.
Increased Loss of CCR5+CD45RA−CD4+T Cells in CD8+Lymphocyte-Depleted Simian Immunodeficiency Virus-Infected Rhesus Monkeys
Authors: Veazey Ronald S. , Acierno Paula M. , McEvers Kimberly J. , Baumeister Susanne H. C. , Foster Gabriel J. , Rett Melisa D. , Newberg Michael H. , Kuroda Marcelo J. , Williams Kenneth , Kim Eun-Young , Wolinsky Steven M. , Rieber E. Peter , Piatak Michael , Lifson Jeffrey D. , Montefiori David C. , Brown Charles R. , Hirsch Vanessa M. , Schmitz Jörn E. 
Published: March 2008

ABSTRACTPreviously we have shown that CD8+T cells are critical for containment of simian immunodeficiency virus (SIV) viremia and that rapid and profound depletion of CD4+T cells occurs in the intestinal tract of acutely infected macaques. To determine the impact of SIV-specific CD8+T-cell responses on the magnitude of the CD4+T-cell depletion, we investigated the effect of CD8+lymphocyte depletion during primary SIV infection on CD4+T-cell subsets and function in peripheral blood, lymph nodes, and intestinal tissues. In peripheral blood, CD8+lymphocyte-depletion changed the dynamics of CD4+T-cell loss, resulting in a more pronounced loss 2 weeks after infection, followed by a temporal rebound approximately 2 months after infection, when absolute numbers of CD4+T cells were restored to baseline levels. These CD4+T cells showed a markedly skewed phenotype, however, as there were decreased levels of memory cells in CD8+lymphocyte-depleted macaques compared to controls. In intestinal tissues and lymph nodes, we observed a significantly higher loss of CCR5+CD45RA−CD4+T cells in CD8+lymphocyte-depleted macaques than in controls, suggesting that these SIV-targeted CD4+T cells were eliminated more efficiently in CD8+lymphocyte-depleted animals. Also, CD8+lymphocyte depletion significantly affected the ability to generate SIV Gag-specific CD4+T-cell responses and neutralizing antibodies. These results reemphasize that SIV-specific CD8+T-cell responses are absolutely critical to initiate at least partial control of SIV infection.
Swallow syncope: reflex or reflux?
Authors: Bajwa S , Stewart J A D , Treadwell S , Lakhani D R 
Published: March 2008

Abstract
A 51-year-old man presented with symptoms of syncope on consuming solid foods. He had a 5 year history of intermittent symptoms on eating only solids and his cardiovascular investigations revealed bradycardia during food ingestion. He was treated by insertion of a pacemaker with cessation of his syncopal symptoms.
Massive cardiac invasion by amelanotic melanoma with obstructive clinical features
Authors: Dubrey S , Grocott-Mason R , Mittal T , Burke M 
Published: March 2008

Abstract
Reports of malignant melanoma involving the heart usually describe metastatic spread of pigmented (melanotic) forms of this tumour. We describe, and illustrate, a patient presenting with features related to cardiac tamponade and intracardiac obstruction. Transthoracic echocardiography initially showed a large mass within the right ventricular outflow tract. The full extent of infiltration of this tumour was demonstrated by computed tomography scanning and the specific tumour type by immunohistochemical staining procedures. The case is unusual in relation to the extreme size of this amelanotic melanoma at presentation and the fact that it appears to be a solitary metastasis.
Directed and Motivated Attention during Processing of Natural Scenes
Authors: Ferrari Vera , Codispoti Maurizio , Cardinale Rossella , Bradley Margaret M. 
Published: March 2008

Abstract
Visual attention can be voluntarily oriented to detect target stimuli in order to facilitate goal-directed behaviors. Other visual stimuli capture attention because of motivational significance. The aim of the present study was to investigate the relationship between directed and motivated attention using event-related potentials. Affectively engaging pictures were presented either as target stimuli or as nontargets in a categorization task. Results indicated that both task relevance and emotional significance modulated the late positive potential (LPP) over centro-parietal sensors. Effects of directed and motivated attention on the LPP were additive, with the largest centro-parietal positivity found for emotional pictures that were targets of directed attention, and the least for neutral pictures that were nontargets. Taken together, the data provide new information regarding the relationship between motivated and directed attention, and suggest that the LPP reflects the operation of attentional neural circuits that are utilized by both top-down and bottom-up processes.
Cortical Dynamics of Anticipatory Mechanisms in Interception: A Neuromagnetic Study
Authors: Senot Patrice , Baillet Sylvain , Renault Bernard , Berthoz Alain 
Published: March 2008

Abstract
Humans demonstrate an amazing ability for intercepting and catching moving targets, most noticeably in fast-speed ball games. However, the few studies exploring the neural bases of interception in humans and the classical studies on visual motion processing and visuomotor interactions have reported rather long latencies of cortical activations that cannot explain the performances observed in most natural interceptive actions. The aim of our experiment was twofold: (1) describe the spatio-temporal unfolding of cortical activations involved in catching a moving target and (2) provide evidence that fast cortical responses can be elicited by a visuomotor task with high temporal constraints and decide if these responses are task or stimulus dependent. Neuromagnetic brain activity was recorded with whole-head coverage while subjects were asked to catch a free-falling ball or simply pay attention to the ball trajectory. A fast, likely stimulus-dependent, propagation of neural activity was observed along the dorsal visual pathway in both tasks. Evaluation of latencies of activations in the main cortical regions involved in the tasks revealed that this entire network of regions was activated within 40 msec. Moreover, comparison of experimental conditions revealed similar patterns of activation except in contralateral sensorimotor regions where common and catch-specific activations were differentiated.
Dissipation of Synoptic-Scale Flow by Small-Scale Turbulence
Authors: Ngan K. , Bartello P. , Straub D. N. 
Published: March 2008

AbstractAlthough it is now accepted that imbalance in the atmosphere and ocean is generic, the feedback of the unbalanced motion on the balanced flow has not received much attention. In this work the parameterization problem is examined in the context of rotating stratified turbulence, that is, with a nonhydrostatic Boussinesq model. Using the normal modes as a first approximation to the balanced and unbalanced flow, the growth of ageostrophic perturbations to the quasigeostrophic flow and the associated feedback are studied. For weak stratification, there are analogies with the three-dimensionalization of decaying 2D turbulence: the growth rate of the ageostrophic perturbation follows a linear estimate, geostrophic energy is extracted from the base flow, and the associated damping on the geostrophic base flow (the “eddy viscosity”) is peaked at large horizontal scales. For strong stratification, the transfer spectra and eddy viscosities maintain this structure if there is synoptic-scale motion and the buoyancy scale is adequately resolved. This has been confirmed for global Rossby and Froude numbers of O(0.1). Implications for atmospheric and oceanic modeling are discussed.
Time Scale and Feedback of Zonal-Mean-Flow Variability
Authors: Son Seok-Woo , Lee Sukyoung , Feldstein Steven B. , Ten Hoeve John E. 
Published: March 2008

Abstract
The physical processes that determine the time scale of zonal-mean-flow variability are examined with an idealized numerical model that has a zonally symmetric lower boundary. In the part of the parameter space where the time-mean zonal flow is characterized by a single (double) jet, the dominant form of zonal-mean-flow variability is the zonal index (poleward propagation), and the time-mean potential vorticity gradient is found to be strong and sharp (weak and broad). The e-folding time scale of the zonal index is found to be close to 55 days, much longer than the observed 10-day time scale. The e-folding time scale of the poleward propagation is about 40 days. The long e-folding time scales for the zonal index are found to be consistent with an unrealistically strong and persistent eddy–zonal-mean-flow feedback. A calculation of the refractive index indicates that the background flow supports eddies that are trapped within midlatitudes, undergoing relatively little meridional propagation.
Additional model runs are performed with an idealized mountain to investigate whether zonal asymmetry can disrupt the eddy feedback. For single-jet states, the time scale is reduced to about 30 days if the mountain height is 4 km or less. The reduction in the time scale occurs because the stationary eddies excited by the mountain alter the background flow in a manner that leads to the replacement of zonal-index events by shorter-time-scale poleward propagation. With a 5-km mountain, the time scale reverts and increases to 105 days. This threshold behavior is again attributed to a sharpening of the background zonal jet, which arises from an extremely strong stationary wave momentum flux convergence. In contrast, for double-jet states, the time scale changes only slightly and the poleward propagation is maintained in all mountain runs.
Infrasound Emitted by Tornado-Like Vortices: Basic Theory and a Numerical Comparison to the Acoustic Radiation of a Single-Cell Thunderstorm
Authors: Schecter David A. , Nicholls Melville E. , Persing John , Bedard Alfred J. , Pielke Roger A. 
Published: March 2008

Abstract
This paper addresses the physics and numerical simulation of the adiabatic generation of infrasound by tornadoes. Classical analytical results regarding the production of infrasound by vortex Rossby waves and by corotating “suction vortices” are reviewed. Conditions are derived for which critical layers damp vortex Rossby waves that would otherwise grow and continually produce acoustic radiation. These conditions are similar to those that theoretically suppress gravity wave radiation from larger mesoscale cyclones, such as hurricanes. To gain perspective, the Regional Atmospheric Modeling System (RAMS) is used to simulate the infrasound that radiates from a single-cell thunderstorm in a shear-free environment. In this simulation, the dominant infrasound in the 0.1–10-Hz frequency band appears to radiate from the vicinity of the melting level, where diabatic processes involving hail are active. It is shown that the 3D Rossby waves of a tornado-like vortex (simulated with RAMS) can generate stronger infrasound if the maximum wind speed of the vortex exceeds a modest threshold. Technical issues regarding the numerical simulation of tornado infrasound are also addressed. Most importantly, it is shown that simulating tornado infrasound likely requires a spatial resolution that is an order of magnitude finer than the current practical limit (10-m grid spacing) for modeling thunderstorms.
Exploring the Possible Role of Small-Scale Terrain Drag on Stable Boundary Layers over Land
Authors: Steeneveld G. J. , Holtslag A. A. M. , Nappo C. J. , van de Wiel B. J. H. , Mahrt L. 
Published: March 2008

Abstract
This paper addresses the possible role of unresolved terrain drag, relative to the turbulent drag on the development of the stable atmospheric boundary layer over land. Adding a first-order estimate for terrain drag to the turbulent drag appears to provide drag that is similar to the enhanced turbulent drag obtained with the so-called long-tail mixing functions. These functions are currently used in many operational models for weather and climate, although they lack a clear physical basis. Consequently, a simple and practical quasi-empirical parameterization of terrain drag divergence for use in large-scale models is proposed and is tested in a column mode. As an outcome, the cross-isobaric mass flow (a measure for cyclone filling) with the new scheme, using realistic turbulent drag, appears to be equal to what is found with the unphysical long-tail scheme. At the same time, the new scheme produces a much more realistic less-deep boundary layer than is obtained by using the long-tail mixing function.
SAL—A Novel Quality Measure for the Verification of Quantitative Precipitation Forecasts
Authors: Wernli Heini , Paulat Marcus , Hagen Martin , Frei Christoph 
Published: March 2008

Abstract
A novel object-based quality measure, which contains three distinct components that consider aspects of the structure (S), amplitude (A), and location (L) of the precipitation field in a prespecified domain (e.g., a river catchment) is introduced for the verification of quantitative precipitation forecasts (QPF). This quality measure is referred to as SAL. The amplitude component A measures the relative deviation of the domain-averaged QPF from observations. Positive values of A indicate an overestimation of total precipitation; negative values indicate an underestimation. For the components S and L, coherent precipitation objects are separately identified in the forecast and observations; however, no matching is performed of the objects in the two datasets. The location component L combines information about the displacement of the predicted (compared to the observed) precipitation field’s center of mass and about the error in the weighted-average distance of the precipitation objects from the total field’s center of mass. The structure component S is constructed in such a way that positive values occur if precipitation objects are too large and/or too flat, and negative values if the objects are too small and/or too peaked. Perfect QPFs are characterized by zero values for all components of SAL. Examples with both synthetic precipitation fields and real data are shown to illustrate the concept and characteristics of SAL. SAL is applied to 4 yr of daily accumulated QPFs from a global and finer-scale regional model for a German river catchment, and the SAL diagram is introduced as a compact means of visualizing the results. SAL reveals meaningful information about the systematic differences in the performance of the two models. While the median of the S component is close to zero for the regional model, it is strongly positive for the coarser-scale global model. Consideration is given to the strengths and limitations of the novel quality measure and to possible future applications, in particular, for the verification of QPFs from convection-resolving weather prediction models on short time scales.
Influence of Suture Material on the Biomechanical Behavior of Suture-Tendon Specimens
Authors: Bisson Leslie J. , Manohar Leslie M. , Wilkins Ryan D. , Gurske-Deperio Jennifer , Ehrensberger Mark T. 
Published: March 2008

Background Despite technical advances in rotator cuff surgery, recurrent or persistent defects in the repaired tendon continue to occur. Improved strength of sutures and suture anchors has resulted in the most common site of failure being the suture-tendon interface. Hypothesis The type of suture material used has a significant effect on the biomechanics of the suture-tendon interface. Study Design Controlled laboratory study. Methods Thirty-two bovine infraspinatus specimens were randomly assigned to simple suture fixation using No. 2 Fiberwire, Ultrabraid, Orthocord, or Ethibond. Each specimen was subjected to cyclic testing from 5 to 30 N for 30 cycles, followed by load-to-failure testing. Results Cyclic testing revealed significantly greater elongation with Ultrabraid, whereas peak-to-peak displacements were lowest for Fiberwire and greatest for Orthocord. Load-to-failure testing revealed no significant differences between any suture material for ultimate tensile load. Fiberwire and Orthocord repairs had the highest stiffness. The most common failure mode during load-to-failure testing was suture breakage in Ethibond specimens and suture cutting through the tendon in the polyblend suture specimens. Conclusion The type of suture material has a significant effect on the biomechanical behavior of the suture-tendon interface. Clinical Relevance The type of suture may influence early gap formation and ultimate healing of rotator cuff repairs.
Biomechanical Assessment of TYPE II Superior Labral Anterior-Posterior (SLAP) Lesions Associated with Anterior Shoulder Capsular Laxity as Seen in Throwers
Authors: Mihata Teruhisa , McGarry Michelle H. , Tibone James E. , Fitzpatrick Michael J. , Kinoshita Mitsuo , Lee Thay Q. 
Published: March 2008

Background Type II superior labral anterior-posterior lesions in throwers are often associated with anterior shoulder capsular laxity. Hypothesis Shoulder instability in patients with type II superior labral anterior-posterior lesions may result from the associated shoulder capsular laxity rather than the superior labral anterior-posterior lesion alone. Study Design Controlled laboratory study. Methods Six cadaveric shoulders were externally rotated to 20% beyond the maximum humeral external rotation at 60° of glenohumeral abduction, which simulated 90° of shoulder abduction, to detach the superior labrum and elongate the anterior shoulder capsular ligaments. The detached labrum was then repaired to isolate the effect of the detached superior labrum and that of the capsular laxity. Rotational range of motion was measured at 60° of glenohumeral abduction. Anterior-posterior glenohumeral translation was measured at 30° and 60° of glenohumeral abduction. Superior-inferior glenohumeral translation was measured at 0° and 60° of glenohumeral abduction. Results The experimentally created type II superior labral anterior-posterior lesion and capsular laxity significantly increased anterior translation at 30° (mean difference, 1.0 ± 0.8 mm; P < .05) and 60° (mean difference, 2.2 ± 2.0 mm; P < .05) of glenohumeral abduction. Subsequent superior labral anterior-posterior repair restored the anterior translation but only at 30° of glenohumeral abduction (mean difference, 0.9 ± 0.6 mm; P < .05). Conclusion Because of the anterior capsular laxity associated with type II superior labral anterior-posterior lesions, superior labral anterior-posterior repair of the peeled-back superior labrum may not restore anterior glenohumeral translation at 90° of shoulder abduction. Clinical Relevance Anterior shoulder capsular laxity associated with type II superior labral anterior-posterior lesions may cause anterior shoulder instability at 90° of shoulder abduction in throwers even after superior labral anterior-posterior lesion repair.