bluuebunny/crossref_metadata_2025 huggingface dataset:
Deformable objects alive!
Authors: Coros Stelian , Martin Sebastian , Thomaszewski Bernhard , Schumacher Christian , Sumner Robert , Gross Markus
Published: August 2012

We present a method for controlling the motions of active deformable characters. As an underlying principle, we require that all motions be driven by
internal
deformations. We achieve this by dynamically adapting rest shapes in order to induce deformations that, together with environment interactions, result in purposeful and physically-plausible motions. Rest shape adaptation is a powerful concept and we show that by restricting shapes to suitable subspaces, it is possible to explicitly control the motion styles of deformable characters. Our formulation is general and can be combined with arbitrary elastic models and locomotion controllers. We demonstrate the efficiency of our method by animating curve, shell, and solid-based characters whose motion repertoires range from simple hopping to complex walking behaviors.
Interactive editing of deformable simulations
Authors: Barbič Jernej , Sin Funshing , Grinspun Eitan
Published: August 2012

We present an interactive animation editor for complex deformable object animations. Given an existing animation, the artist directly manipulates the deformable body at any time frame, and the surrounding animation immediately adjusts in response. The automatic adjustments are designed to respect physics, preserve detail in both the input motion and geometry, respect prescribed bilateral contact constraints, and controllably and smoothly decay in space-time. While the utility of interactive editing for rigid body and articulated figure animations is widely recognized, a corresponding approach to deformable bodies has not been technically feasible before. We achieve interactive rates by combining spacetime model reduction, rotation-strain coordinate warping, linearized elasticity, and direct manipulation. This direct editing tool can serve the final stages of animation production, which often call for detailed, direct adjustments that are otherwise tedious to realize by re-simulation or frame-by-frame editing.
Robust modeling of constant mean curvature surfaces
Authors: Pan Hao , Choi Yi-King , Liu Yang , Hu Wenchao , Du Qiang , Polthier Konrad , Zhang Caiming , Wang Wenping
Published: August 2012

We present a new method for modeling discrete constant mean curvature (CMC) surfaces, which arise frequently in nature and are highly demanded in architecture and other engineering applications. Our method is based on a novel use of the CVT (
centroidal Voronoi tessellation
) optimization framework. We devise a CVT-CMC energy function defined as a combination of an extended CVT energy and a volume functional. We show that minimizing the CVT-CMC energy is asymptotically equivalent to minimizing mesh surface area with a fixed volume, thus defining a discrete CMC surface. The CVT term in the energy function ensures high mesh quality throughout the evolution of a CMC surface in an interactive design process for form finding. Our method is capable of modeling CMC surfaces with fixed or free boundaries and is robust with respect to input mesh quality and topology changes. Experiments show that the new method generates discrete CMC surfaces of improved mesh quality over existing methods.
Design of self-supporting surfaces
Authors: Vouga Etienne , Höbinger Mathias , Wallner Johannes , Pottmann Helmut
Published: August 2012

Self-supporting masonry is one of the most ancient and elegant techniques for building curved shapes. Because of the very geometric nature of their failure, analyzing and modeling such strutures is more a geometry processing problem than one of classical continuum mechanics. This paper uses the thrust network method of analysis and presents an iterative nonlinear optimization algorithm for efficiently approximating freeform shapes by self-supporting ones. The rich geometry of thrust networks leads us to close connections between diverse topics in discrete differential geometry, such as a finite-element discretization of the Airy stress potential, perfect graph Laplacians, and computing admissible loads via curvatures of polyhedral surfaces. This geometric viewpoint allows us, in particular, to remesh self-supporting shapes by self-supporting quad meshes with planar faces, and leads to another application of the theory: steel/glass constructions with low moments in nodes.
Push it real
Authors: Hoyet Ludovic , McDonnell Rachel , O'Sullivan Carol
Published: August 2012

With recent advances in real-time graphics technology, more realistic, believable and appealing virtual characters are needed than ever before. Both player-controlled avatars and non-player characters are now starting to interact with the environment, other virtual humans and crowds. However, simulating physical contacts between characters and matching appropriate reactions to specific actions is a highly complex problem, and timing errors, force mismatches and angular distortions are common. To investigate the effect of such anomalies on the perceived realism of two-character interactions, we captured a motion corpus of pushing animations and corresponding reactions and then conducted a series of perceptual experiments. We found that participants could easily distinguish between five different interaction forces, even when only one of the characters was visible. Furthermore, they were sensitive to all three types of anomalous interactions: timing errors of over 150ms were acceptable less than 50% of the time, with early or late reactions being equally perceptible; participants could perceive force mismatches, though over-reactions were more acceptable than under-reactions; finally, angular distortions when a character reacts to a pushing force reduce the acceptability of the interactions, but there is some evidence for a preference of expansion away from the pushing character's body. Our results provide insights to aid in designing motion capture sessions, motion editing strategies and balancing animation budgets.
Adaptive image-based intersection volume
Authors: Wang Bin , Faure François , Pai Dinesh K.
Published: August 2012

A method for image-based contact detection and modeling, with guaranteed precision on the intersection volume, is presented. Unlike previous image-based methods, our method optimizes a nonuniform ray sampling resolution and allows precise control of the volume error. By cumulatively projecting all mesh edges into a generalized 2D texture, we construct a novel data structure, the Error Bound Polynomial Image (EBPI), which allows efficient computation of the maximum volume error as a function of ray density. Based on a precision criterion, EBPI pixels are subdivided or clustered. The rays are then cast in the projection direction according to the non-uniform resolution. The EBPI data, combined with ray-surface intersection points and normals, is also used to detect transient edges at surface intersections. This allows us to model intersection volumes at arbitrary resolution, while avoiding the geometric computation of mesh intersections. Moreover, the ray casting acceleration data structures can be reused for the generation of high quality images.
Energy-based self-collision culling for arbitrary mesh deformations
Authors: Zheng Changxi , James Doug L.
Published: August 2012

In this paper, we accelerate self-collision detection (SCD) for a deforming triangle mesh by exploiting the idea that a mesh cannot self collide unless it deforms enough. Unlike prior work on subspace self-collision culling which is restricted to low-rank deformation subspaces, our energy-based approach supports arbitrary mesh deformations while still being fast. Given a bounding volume hierarchy (BVH) for a triangle mesh, we precompute Energy-based Self-Collision Culling (ESCC) certificates on bounding-volume-related sub-meshes which indicate the amount of deformation energy required for it to self collide. After updating energy values at runtime, many bounding-volume self-collision queries can be culled using the ESCC certificates. We propose an affine-frame Laplacian-based energy definition which sports a highly optimized certificate pre-process, and fast runtime energy evaluation. The latter is performed hierarchically to amortize Laplacian energy and affine-frame estimation computations. ESCC supports both discrete and continuous SCD with detailed and nonsmooth geometry. We observe significant culling on many examples, with SCD speed-ups up to 26X.
Motion-driven concatenative synthesis of cloth sounds
Authors: An Steven S. , James Doug L. , Marschner Steve
Published: August 2012

We present a practical data-driven method for automatically synthesizing plausible soundtracks for physics-based cloth animations running at graphics rates. Given a cloth animation, we analyze the deformations and use motion events to drive crumpling and friction sound models estimated from cloth measurements. We synthesize a low-quality sound signal, which is then used as a target signal for a concatenative sound synthesis (CSS) process. CSS selects a sequence of microsound units, very short segments, from a database of recorded cloth sounds, which best match the synthesized target sound in a low-dimensional feature-space after applying a hand-tuned warping function. The selected microsound units are concatenated together to produce the final cloth sound with minimal filtering. Our approach avoids expensive physics-based synthesis of cloth sound, instead relying on cloth recordings and our motion-driven CSS approach for realism. We demonstrate its effectiveness on a variety of cloth animations involving various materials and character motions, including first-person virtual clothing with binaural sound.
Precomputed acceleration noise for improved rigid-body sound
Authors: Chadwick Jeffrey N. , Zheng Changxi , James Doug L.
Published: August 2012

We introduce an efficient method for synthesizing acceleration noise -- sound produced when an object experiences abrupt rigid-body acceleration due to collisions or other contact events. We approach this in two main steps. First, we estimate continuous contact force profiles from rigid-body impulses using a simple model based on Hertz contact theory. Next, we compute solutions to the acoustic wave equation due to short acceleration pulses in each rigid-body degree of freedom. We introduce an efficient representation for these solutions --
Precomputed Acceleration Noise
-- which allows us to accurately estimate sound due to arbitrary rigid-body accelerations. We find that the addition of acceleration noise significantly complements the standard modal sound algorithm, especially for small objects.
Reflections on simultaneous impact
Authors: Smith Breannan , Kaufman Danny M. , Vouga Etienne , Tamstorf Rasmus , Grinspun Eitan
Published: August 2012

Resolving simultaneous impacts is an open and significant problem in collision response modeling. Existing algorithms in this domain fail to fulfill at least one of five physical desiderata. To address this we present a simple generalized impact model motivated by both the successes and pitfalls of two popular approaches: pair-wise propagation and linear complementarity models. Our algorithm is the first to satisfy all identified desiderata, including simultaneously guaranteeing symmetry preservation, kinetic energy conservation, and allowing break-away. Furthermore, we address the associated problem of inelastic collapse, proposing a complementary generalized restitution model that eliminates this source of nontermination. We then consider the application of our models to the
synchronous
time-integration of large-scale assemblies of impacting rigid bodies. To enable such simulations we formulate a consistent frictional impact model that continues to satisfy the desiderata. Finally, we validate our proposed algorithm by correctly capturing the observed characteristics of physical experiments including the phenomenon of extended patterns in vertically oscillated granular materials.
Bounded distortion mapping spaces for triangular meshes
Authors: Lipman Yaron
Published: August 2012

The problem of mapping triangular meshes into the plane is fundamental in geometric modeling, where planar deformations and surface parameterizations are two prominent examples. Current methods for triangular mesh mappings cannot, in general, control the worst case distortion of all triangles nor guarantee injectivity.

This paper introduces a constructive definition of generic convex spaces of piecewise linear mappings with guarantees on the maximal conformal distortion, as-well as local and global injectivity of their maps. It is shown how common geometric processing objective functionals can be restricted to these new spaces, rather than to the entire space of piecewise linear mappings, to provide a bounded distortion version of popular algorithms.
Dual loops meshing
Authors: Campen Marcel , Bommes David , Kobbelt Leif
Published: August 2012

We present a theoretical framework and practical method for the automatic construction of simple, all-quadrilateral patch layouts on manifold surfaces. The resulting layouts are coarse, surface-embedded cell complexes well adapted to the geometric structure, hence they are ideally suited as domains and base complexes for surface parameterization, spline fitting, or subdivision surfaces and can be used to generate quad meshes with a high-level patch structure that are advantageous in many application scenarios. Our approach is based on the careful construction of the layout graph's combinatorial dual. In contrast to the primal this dual perspective provides direct control over the globally interdependent structural constraints inherent to quad layouts. The dual layout is built from curvature-guided, crossing loops on the surface. A novel method to construct these efficiently in a geometry- and structure-aware manner constitutes the core of our approach.
Lagrangian vortex sheets for animating fluids
Authors: Pfaff Tobias , Thuerey Nils , Gross Markus
Published: August 2012

Buoyant turbulent smoke plumes with a sharp smoke-air interface, such as volcanic plumes, are notoriously hard to simulate. The surface clearly shows small-scale turbulent structures which are costly to resolve. In addition, the turbulence onset is directly visible at the interface, and is not captured by commonly used turbulence models. We present a novel approach that employs a triangle mesh as a high-resolution surface representation combined with a coarse Eulerian solver. On the mesh, we solve the interfacial vortex sheet equations, which allows us to accurately simulate buoyancy induced turbulence. For complex boundary conditions we propose an orthogonal turbulence model that handles vortices caused by obstacle interaction. In addition, we demonstrate a re-sampling scheme to remove surfaces that are hidden inside the bulk volume. In this way we are able to achieve highly detailed simulations of turbulent plumes efficiently.
Discrete viscous sheets
Authors: Batty Christopher , Uribe Andres , Audoly Basile , Grinspun Eitan
Published: August 2012

We present the first reduced-dimensional technique to simulate the dynamics of thin sheets of viscous incompressible liquid in three dimensions. Beginning from a discrete Lagrangian model for elastic thin shells, we apply the Stokes-Rayleigh analogy to derive a simple yet consistent model for viscous forces. We incorporate nonlinear surface tension forces with a formulation based on minimizing discrete surface area, and preserve the quality of triangular mesh elements through local remeshing operations. Simultaneously, we track and evolve the thickness of each triangle to exactly conserve liquid volume. This approach enables the simulation of extremely thin sheets of viscous liquids, which are difficult to animate with existing volumetric approaches. We demonstrate our method with examples of several characteristic viscous sheet behaviors, including stretching, buckling, sagging, and wrinkling.
Physical face cloning
Authors: Bickel Bernd , Kaufmann Peter , Skouras Mélina , Thomaszewski Bernhard , Bradley Derek , Beeler Thabo , Jackson Phil , Marschner Steve , Matusik Wojciech , Gross Markus
Published: August 2012

We propose a complete process for designing, simulating, and fabricating synthetic skin for an animatronics character that mimics the face of a given subject and its expressions. The process starts with measuring the elastic properties of a material used to manufacture synthetic soft tissue. Given these measurements we use physics-based simulation to predict the behavior of a face when it is driven by the underlying robotic actuation. Next, we capture 3D facial expressions for a given target subject. As the key component of our process, we present a novel optimization scheme that determines the shape of the synthetic skin as well as the actuation parameters that provide the best match to the target expressions. We demonstrate this computational skin design by physically cloning a real human face onto an animatronics figure.
Video streaming using a location-based bandwidth-lookup service for bitrate planning
Authors: Riiser Haakon , Endestad Tore , Vigmostad Paul , Griwodz Carsten , Halvorsen Pâl
Published: August 2012

A lot of people around the world commute using public transportation and would like to spend this time viewing streamed video content such as news or sports updates. However, mobile wireless networks typically suffer from severe bandwidth fluctuations, and the networks are often completely unresponsive for several seconds, sometimes minutes. Today, there are several ways of adapting the video bitrate and thus the video quality to such fluctuations, for example, using scalable video codecs or segmented adaptive HTTP streaming that switches between nonscalable video streams encoded in different bitrates. Still, for a better long-term video playout experience that avoids disruptions and frequent quality changes while using existing video adaptation technology, it is desirable to perform bandwidth prediction and planned quality adaptation.

This article describes a video streaming system for receivers equipped with a GPS. A receiver's download rate is constantly monitored, and periodically reported back to a central database along with associated GPS positional data. Thus, based on the current location, a streaming device can use a GPS-based bandwidth-lookup service in order to better predict the near-future bandwidth availability and create a schedule for the video playout that takes likely future availability into account. To create a prototype and perform initial tests, we conducted several field trials while commuting using public transportation. We show how our database has been used to predict bandwidth fluctuations and network outages, and how this information helps maintain uninterrupted playback with less compromise on video quality than possible without prediction.
Automatic evaluation of video summaries
Authors: Valdes Victor , Martinez Jose M.
Published: August 2012

This article describes a method for the automatic evaluation of video summaries based on the training of individual predictors for different quality measures from the TRECVid 2008 BBC Rushes Summarization Task. The obtained results demonstrate that, with a large set of evaluation data, it is possible to train fully automatic evaluation systems based on visual features automatically extracted from the summaries. The proposed approach will enable faster and easier estimation of the results of newly developed abstraction algorithms and the study of which summary characteristics influence their perceived quality.
A control theoretic scheme for efficient video transmission over IEEE 802.11e EDCA WLANs
Authors: Patras Paul , Banchs Albert , Serrano Pablo
Published: August 2012

The EDCA mechanism of the IEEE 802.11 standard has been designed to support, among others, video traffic. This mechanism relies on a number of parameters whose configuration is left open by the standard. Although there are some recommended values for these parameters, they are fixed independent of the WLAN conditions, which results in suboptimal performance. Following this observation, a number of approaches in the literature have been devised to set the EDCA parameters based on an estimation of the WLAN conditions. However, these previous approaches are based on heuristics and hence do not guarantee optimized performance. In this article we propose a novel algorithm to adjust the EDCA parameters to carry video traffic which, in contrast to previous approaches, is sustained on mathematical foundations that guarantee optimal performance. In particular, our approach builds upon (i) an analytical model of the WLAN performance under video traffic, used to derive the optimal point of operation of EDCA, and (ii) a control theoretic designed mechanism which drives the WLAN to this point of operation. Via extensive simulations, we show that the proposed approach performs optimally and substantially outperforms the standard recommended configuration as well as previous adaptive proposals.
Vitreous Levels of Proteins Implicated in Angiogenesis Are Modulated in Patients with Retinal or Choroidal Neovascularization
Authors: Huber Matthias , Wachtlin Joachim
Published: August 2012

Aim: The aim of this study was to investigate the levels of pigment epithelium-derived factor (PEDF), angiopoietin 2, vascular endothelial growth factor (VEGF), and soluble VEGF receptor 1 (sVEGFR-1) in vitreous samples of patients suffering from age-related macular degeneration with choroidal neovascularization or from proliferative diabetic retinopathy (PDR). Methods: Proteins in vitreous samples of 29 patients were quantified via enzyme-linked immunosorbent assays. Results: Vitreous levels of sVEGFR-1 were significantly higher in age-related macular degeneration with choroidal neovascularization (p = 0.005) and in PDR (p = 0.003) versus controls. In analogue comparisons, PEDF was significantly decreased (p < 0.01). PDR was associated with significantly increased angiopoietin 2 and VEGF levels (p = 0.001 for both). Conclusion: The vitreous in retinal or choroidal neovascularization revealed a pro-angiogenic potential indicated by decreased PEDF or increased angiopoietin 2 levels compared to controls. However, higher amounts of sVEGFR-1 were concomitant, pointing to activation of an endogenous anti-angiogenic system in the protein network.
Laparoendoscopic Single-Site Surgery for Symptomatic Renal Cyst Decortication Using a Homemade Glove Port Device: Initial Experience
Authors: Liu Chunxiao , Pan Bin , Zheng Shaobo , Xu Abai
Published: August 2012

Objectives: Laparoendoscopic single-site surgery (LESS) has recently gained popularity in urology. There are few large series reports on LESS for symptomatic renal cysts. We evaluated the clinical utility and safety of LESS in 62 symptomatic renal cyst decortication patients by using a homemade glove port device. Materials and Methods: We reviewed our series of 62 LESS for symptomatic renal cyst (20 Bosniak type I and 42 Bosniak type II) decortication performed from November 2009 to December 2010. A homemade glove port device was placed through an umbilical incision. The perioperative clinical parameters were reviewed retrospectively. Results: Of 62 cases that underwent LESS for renal cyst ablation successfully, there were no major perioperative complications, but 2 minor complications (transient fever and mild ileus) were found. The mean operative time was 61.4 ± 27.4 min and the mean estimated blood loss was 20.1 ± 11.3 ml. The mean pre- and postoperative pain scores were 6.94 ± 1.1 (range 5–10) and 1.3 ± 1.2 (0–5), respectively (p = 0.000). Conclusions: Our results suggest that LESS is a safe and feasible alternative to conventional laparoscopic surgery for the treatment of symptomatic renal cysts.
Pathophysiology of the Small Airways in Chronic Obstructive Pulmonary Disease
Authors: Baraldo Simonetta , Turato Graziella , Saetta Marina
Published: August 2012

Chronic obstructive pulmonary disease (COPD) is characterized by a persistent airflow limitation that is usually progressive and associated with an enhanced chronic inflammatory response in the airways and the lung to noxious particles or gases. From a pathological point of view, COPD is characterized by two distinct and frequently coexisting aspects: small airway abnormalities and parenchymal destruction (or emphysema). When pathological changes are localized in lung parenchyma, they will contribute to airflow limitation by reducing the elastic recoil of the lung through parenchymal destruction, as well as by reducing the elastic load applied to the airways through destruction of alveolar attachments. Conversely, when pathological changes involve the small airways, they will contribute to airflow limitation by narrowing and obliterating the lumen and by actively constricting the airways, therefore increasing the resistance. In this article we will review the structural abnormalities in small airways and their relationship with the disordered pulmonary function in COPD, in the attempt to disentangle the mechanisms contributing to the development and progression of airflow limitation in smokers. We will start by describing the normal structure of the small airways, and then observe the main pathological alterations that accumulate in this site and how they parallel pulmonary function derangement.
Polite Requestive Strategies in Emails: An Investigation of Pragmatic Competence of Chinese EFL Learners
Authors: Zhu Wuhan
Published: August 2012

This paper is motivated by the premise that little is known about the use of requestive strategies in request emails in Chinese English-as-a-Foreign-Language (EFL) context. Specifically, the paper examines and compares requestive strategies in request emails between two groups of university students, namely English majors (EM) and non-English majors (NEM). It then explores whether the assessments of three situational factors: assessments of social distance, power and rank of imposition, either alone or combined, has a statistically significant effect on the choice of requestive strategies by the two groups. In reference to some existing similar research, the paper argues that both groups under study seemed to exhibit inadequate sociopragmatic competence and pragmalinguistic knowledge. The study thus sheds some light on Interlanguage Pragmatics research on the Chinese EFL context. The paper finally offers some pedagogical implications in foreign language settings.
Ultra-high resolution HLA genotyping and allele discovery by highly multiplexed cDNA amplicon pyrosequencing
Authors: Lank Simon M , Golbach Brittney A , Creager Hannah M , Wiseman Roger W , Keskin Derin B , Reinherz Ellis L , Brusic Vladimir , O’Connor David H
Published: August 2012

Background

High-resolution HLA genotyping is a critical diagnostic and research assay. Current methods rarely achieve unambiguous high-resolution typing without making population-specific frequency inferences due to a lack of locus coverage and difficulty in exon-phase matching. Achieving high-resolution typing is also becoming more challenging with traditional methods as the database of known HLA alleles increases.

Results

We designed a cDNA amplicon-based pyrosequencing method to capture 94% of the HLA class I open-reading-frame with only two amplicons per sample, and an analogous method for class II HLA genes, with a primary focus on sequencing the DRB loci. We present a novel Galaxy server-based analysis workflow for determining genotype. During assay validation, we performed two GS Junior sequencing runs to determine the accuracy of the HLA class I amplicons and DRB amplicon at different levels of multiplexing. When 116 amplicons were multiplexed, we unambiguously resolved 99%of class I alleles to four- or six-digit resolution, as well as 100% unambiguous DRB calls. The second experiment, with 271 multiplexed amplicons, missed some alleles, but generated high-resolution, concordant typing for 93% of class I alleles, and 96% for DRB1 alleles. In a third, preliminary experiment we attempted to sequence novel amplicons for other class II loci with mixed success.

Conclusions

The presented assay is higher-throughput and higher-resolution than existing HLA genotyping methods, and suitable for allele discovery or large cohort sampling. The validated class I and DRB primers successfully generated unambiguously high-resolution genotypes, while further work is needed to validate additional class II genotyping amplicons.
Vitamin E and telmisartan attenuates doxorubicin induced cardiac injury in rat through down regulation of inflammatory response
Authors: Hadi Najah , Yousif Nasser Ghaly , Al-amran Fadhil G , Huntei Nadhem K , Mohammad Bassim I , Ali Sadiq J
Published: August 2012

Background

The importance of doxorubicin (Dox), as a potent antitumor antibiotic, is limited by the development of life-threatening cardiomyopathy. It has been shown that free radicals are involved in acute doxorubicin-induced toxicity. The aim of this study was to determine the protective effect of vitamin E and telmisartan in acute doxorubicin induced cardiotoxicity.

Methods

Thirty two male Sprague - Dawly rats were involved in this study and were randomly separated into 4 groups, eight rats in each group, one group received normal saline I.P as control and second group received doxorubicin 20 mg/kg I.P, the other two groups also received doxorubicin 20 mg/kg I.P as single dose after seven cumulative doses (for seven days) of vitamin E (100 mg/kg) and telmisartan (1 mg/kg) respectively. Immunofluorescent staining for monocytes infiltration and analyses of plasma by (ELISAs) for MCP-1and troponin I. Western immunoblotting assay for ICAM-1, while left ventricular function was analyzed by microcatheter, also estimated the level of oxidative stress parameters (MDA and Catalase) and cardiac enzymes activities (CK-MB and LDH) before starting drugs treatment and after treatment period by 48 hours.

Results

The immunofluorescent staining showed that administration of vitamin E and telmisartan are attenuated of mononuclear cell infiltration; (p < 0.05 vs. Dox group), also reduced the level of chemokines MCP-1 and ICAM-1 expression compared with Dox group only, and there is marked reduction of myocardial troponin-I levels with improved LV function in vitamin E and telmisartan treated group. Doxorubicin treatment increased MDA, LDH, CK-MB levels significantly (P < 0.01), and were counteracted by administration of vitamin E and telmisartan, but did not significantly affect serum catalase activity.

Conclusions

Antioxidant effect (Vitamin E and telmisartan) have been shown to decrease doxorubicininduced cardiotoxicity.
Analysis of the causes and clinical characteristics of jejunoileal hemorrhage in China: a multicenter 10 year retrospective survey
Authors: Jiang Da-lei , Liu Hui-ya , Yuan Yong , Sui Jian-chao , Jing Chang-chun , Jiang Kai-tong , Wang Qing-cai , Yuan Sheng-an , Chen Hai-ying , Gao Yan-jing
Published: August 2012

Background

A retrospective study was performed to assess the causes, diagnostic methods for, and clinical features of, jejunoileal hemorrhage in Shandong province, China and to derive recommendations for management of this condition from these data.

Methods

We performed a retrospective systematic collection of data from between January 1999 and December 2008 in seven cities in Shandong province, China, identified 72 patients with jejunoileal hemorrhage and analyzed the relevant clinical data.

Results

Overall, tumors were the most common cause of jejunoileal hemorrhage (42 patients, 58.3%). The causes of this condition were significantly different (P < 0.05) in male and female patients. In male patients, the commonest factors were tumor (52.2%), enteritis (17.4%) and angiopathy (15.2%). However, in female patients, tumors accounted for a greater proportion of cases (18/26, 69.2%). In 38 cases (52.8%) the diagnosis was made by intraoperative enteroscopy or laparotomy, in 14 by capsule endoscopy and in the remainder by radiological methods. The most frequent presentation was melena (62.7%), followed by maroon stools (26.9%) and hematochezia (9.0%). Of the 72 patients,laparotomy is the main treatment method.

Conclusion

Tumor, enteritis and angiopathy and diverticular disease are the most common causes of jejunoileal hemorrhage in Shandong province, China. The main clinical manifestations are bloody stools, most commonly in the form of melena, with or without abdominal pain. We recommend that female patients over the age of 40 with jejunoileal hemorrhage accompanied by abdominal pain should undergo urgent further assessment because of the strong probability of jejunoileal tumor.
Short hairpin RNA targeting 2B gene of coxsackievirus B3 exhibits potential antiviral effects both in vitro and in vivo
Authors: Yao Hailan , Zhang Yangde , He Feng , Wang Caihong , Xiao Zonghui , Zou Jizhen , Wang Fang , Liu Zhewei
Published: August 2012

Background

Coxsackievirus B3 is an important infectious agent of viral myocarditis, pancreatitis and aseptic meningitis, but there are no specific antiviral therapeutic reagents in clinical use. RNA interference-based technology has been developed to prevent the viral infection.

Methods

To evaluate the impact of RNA interference on viral replication, cytopathogenicity and animal survival, short hairpin RNAs targeting the viral 2B region (shRNA-2B) expressed by a recombinant vector (pGCL-2B) or a recombinant lentivirus (Lenti-2B) were tansfected in HeLa cells or transduced in mice infected with CVB3.

Results

ShRNA-2B exhibited a significant effect on inhibition of viral production in HeLa cells. Furthermore, shRNA-2B improved mouse survival rate, reduced the viral tissues titers and attenuated tissue damage compared with those of the shRNA-NC treated control group. Lenti-2B displayed more effective role in inhibition of viral replication than pGCL-2B in vivo.

Conclusions

Coxsackievirus B3 2B is an effective target of gene silencing against coxsackievirus B3 infection, suggesting that shRNA-2B is a potential agent for further development into a treatment for enterviral diseases.
Estrogen receptor alpha gene polymorphisms and risk of HBV-related acute liver failure in the Chinese population
Authors: Yan Zehui , Tan Wenting , Dan Yunjie , Zhao Wenli , Deng Chunqing , Wang Yuming , Deng Guohong
Published: August 2012

Background

The sexual dimorphism of hepatitis B virus (HBV) -related liver diseases is related with estrogen and its receptors. Recent reports indicate that abnormal expression of estrogen receptor alpha (ESR1) may be a hallmark for the progression of liver disease and HBV carriers presenting variant ESR1 have an extremely aggressive clinical course. Here we examine whether the ESR1 polymorphisms or its haplotypes are related to HBV-related acute liver failure (ALF) risk among chronic HBV carriers in a Chinese population.

Methods

A total of 1216 unrelated Han Chinese HBV carriers were recruited in this hospital-based case–control study, including 359 HBV surface antigen (HBsAg) carriers affected with ALF and 857 asymptomatic HBsAg carriers. Two ESR1 haplotype tagging polymorphisms, c.30 T > C (rs2077647) and c.453-397 T > C (rs2234693), were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay.

Results

We observed a significantly increased susceptibility to HBV-ALF associated with the c.30 C allele (P = 8.65 × 10-4), c.453-397 C allele (5.37 × 10-4) and [c.30 C; c.453-397 C] haplotype (Dominant model, P =0.0004, odds ratio = 1.53, 95% CI 1.23 ~ 1.96) compared with the T alleles and [c.30 T; c.453-397 T] haplotype of c.30 T > C and c.453-397 T > C polymorphisms, respectively.

Conclusions

Our study suggests that [c.30 C; c.453-397 C] hapotype may be a risk factor for genetic susceptibility to HBV-related ALF in the Chinese population. It also emphasizes the importance of ESR1 in the pathophysiology of HBV-related ALF on the population level.
Could albumin level explain the higher mortality in hemodialysis patients with pulmonary hypertension?
Authors: Yoo Hugo Hyung Bok , Martin Luis Cuadrado , Kochi Ana Claudia , Rodrigues-Telini Lidiane Silva , Barretti Pasqual , Caramori Jacqueline Teixeira , Matsubara Beatriz Bojikian , Zannati-Bazan Silméia Garcia , da Silva Franco Roberto Jorge , Queluz Thais Thomaz
Published: August 2012

Background

The pathogenesis of pulmonary hypertension (PH) in hemodialysis is still unclear. The aim of this study was to identify the risk factors associated with the presence of PH in chronic hemodialysis patients and to verify whether these factors might explain the highest mortality among them.

Methods

We conducted a retrospective study of hemodialysis patients who started treatment from August 2001 to October 2007 and were followed up until April 2011 in a Brazilian referral medical school. According to the results of echocardiography examination, patients were allocated in two groups: those with PH and those without PH. Clinical parameters, site and type of vascular access, bioimpedance, and laboratorial findings were compared between the groups and a logistic regression model was elaborated. Actuarial survival curves were constructed and hazard risk to death was evaluated by Cox regression analysis.

Results

PH > 35 mmHg was found in 23 (30.6%) of the 75 patients studied. The groups differed in extracellular water, ventricular thickness, left atrium diameter, and ventricular filling. In a univariate analysis, extracellular water was associated with PH (relative risk = 1.194; 95% CI of 1.006 – 1.416; p = 0.042); nevertheless, in a multiple model, only left atrium enlargement was independently associated with PH (relative risk =1.172; 95% CI of 1.010 – 1.359; p = 0.036). PH (hazard risk = 3.008; 95% CI of 1.285 – 7.043; p = 0.011) and age (hazard risk of 1.034 per year of age; 95% CI of 1.000 – 7.068; p = 0.047) were significantly associated with mortality in a multiple Cox regression analysis. However, when albumin was taken in account the only statistically significant association was between albumin level and mortality (hazard risk = 0.342 per g/dL; 95% CI of 0.119 – 0.984; p = 0.047) while the presence of PH lost its statistical significance (p = 0.184). Mortality was higher in patients with PH (47.8% vs 25%) who also had a statistically worse survival after the sixth year of follow up.

Conclusions

PH in hemodialysis patients is associated with parameters of volume overload that sheds light on its pathophysiology. Mortality is higher in hemodialysis patients with PH and the low albumin level can explain this association.
A case of rapidly progressive IgA nephropathy in a patient with exacerbation of Crohn’s disease
Authors: Choi Ji-Young , Yu Chung Hoon , Jung Hee-Yeon , Jung Min Kyu , Kim Yong-Jin , Cho Jang-Hee , Kim Chan-Duck , Kim Yong-Lim , Park Sun-Hee
Published: August 2012

Background

IgA nephropathy has been reported as a renal involvement in Crohn’s disease. Crescentic IgA nephropathy, which accounts for fewer than 5% of cases of IgA nephropathy, has a poorer prognosis than other forms of crescentic glomerulonephritis. We recently experienced a case of rapidly progressive IgA nephropathy concurrent with exacerbation of Crohn’s disease.

Case presentation

An 18-year-old male diagnosed with Crohn’s disease underwent a hemicolectomy 2 years prior previously. He had maintained a state of Crohn’s disease remission with 5-aminosalicylic acid treatment. Four months prior to referral to the nephrology clinic, he experienced non-bloody diarrhea. He simultaneously developed proteinuria and microscopic hematuria with deterioration of renal function. Based on renal biopsy findings, the patient was diagnosed with crescentic IgA nephropathy. Immunostaining for interleukin-17 in renal tissue and previous exacerbated colonic ulcers was positive. Steroid pulse therapy was administered, followed by high-dose glucocorticoid and oral cyclophosphamide therapy. The patient’s renal function recovered and his gastrointestinal symptoms were alleviated.

Conclusions

We report a case of crescentic IgA nephropathy presenting with exacerbation of Crohn’s disease, and present a review of the literature focusing on the pathophysiologic relationship between these two conditions.
Assessment of visual disability using visual evoked potentials
Authors: Jeon Jihoon , Oh Seiyul , Kyung Sungeun
Published: August 2012

Background

The purpose of this study is to validate the use of visual evoked potential (VEP) to objectively quantify visual acuity in normal and amblyopic patients, and determine if it is possible to predict visual acuity in disability assessment to register visual pathway lesions.

Methods

A retrospective chart review was conducted of patients diagnosed with normal vision, unilateral amblyopia, optic neuritis, and visual disability who visited the university medical center for registration from March 2007 to October 2009. The study included 20 normal subjects (20 right eyes: 10 females, 10 males, ages 9–42 years), 18 unilateral amblyopic patients (18 amblyopic eyes, ages 19–36 years), 19 optic neuritis patients (19 eyes: ages 9–71 years), and 10 patients with visual disability having visual pathway lesions. Amplitude and latencies were analyzed and correlations with visual acuity (logMAR) were derived from 20 normal and 18 amblyopic subjects. Correlation of VEP amplitude and visual acuity (logMAR) of 19 optic neuritis patients confirmed relationships between visual acuity and amplitude. We calculated the objective visual acuity (logMAR) of 16 eyes from 10 patients to diagnose the presence or absence of visual disability using relations derived from 20 normal and 18 amblyopic eyes.

Results

Linear regression analyses between amplitude of pattern visual evoked potentials and visual acuity (logMAR) of 38 eyes from normal (right eyes) and amblyopic (amblyopic eyes) subjects were significant [y = −0.072x + 1.22, x: VEP amplitude, y: visual acuity (logMAR)]. There were no significant differences between visual acuity prediction values, which substituted amplitude values of 19 eyes with optic neuritis into function. We calculated the objective visual acuity of 16 eyes of 10 patients to diagnose the presence or absence of visual disability using relations of y = −0.072x + 1.22 (−0.072). This resulted in a prediction reference of visual acuity associated with malingering vs. real disability in a range >5.77 μV. The results could be useful, especially in cases of no obvious pale disc with trauma.

Conclusions

Visual acuity quantification using absolute value of amplitude in pattern visual evoked potentials was useful in confirming subjective visual acuity for cutoff values >5.77 μV in disability evaluation to discriminate the malingering from real disability.
Tumor budding as a risk factor of lymph node metastasis in submucosal invasive T1 colorectal carcinoma: a retrospective study
Authors: Kye Bong-Hyeon , Jung Ji-Han , Kim Hyung-Jin , Kang Se-Goo , Cho Hyeon-Min , Kim Jun-Gi
Published: August 2012

Background

This study was designed to identify risk factors for lymph node metastasis of early stage colorectal cancer, which was confirmed to a carcinoma that invaded the submucosa after radical resection.

Methods

In total, 55 patients revealing submucosal invasive colorectal carcinoma on pathology who underwent curative radical resection at the Department of Surgery, St. Vincent’s Hospital, The Catholic University of Korea from January 2007 to September 2010 were evaluated retrospectively. Tumor size, depth of submucosal invasion, histologic grade, lymphovascular invasion, tumor budding, and microacinar structure were reviewed by a single pathologist. Student t-test for continuous variables and Chi-square test for categorical variables were used for comparing the clinicopathological features between two groups (whether lymph node involvement existed or not). Continuous variables are expressed as the mean ± standard error while statistical significance is accepted at P < 0.05.

Results

The mean age of 55 patients (34 males and 21 females) was 61.2 ± 9.6 years (range, 43–83). Histologically, eight (14.5%) patients had metastatic lymph node. In the univariate analysis, tumor budding (P = 0.047) was the only factor that was significantly associated with lymph node metastasis. Also, the tumor budding had a sensitivity of 83.3%, a specificity of 60.5%, and a negative predictive value of 0.958 for lymph node metastasis in submucosal invasive T1 colorectal cancer.

Conclusions

The tumor budding seems to have a high sensitivity (83.3%), acceptable specificity (60.5%), and a high negative predictive value (0.958). A close examination of pathologic finding including tumor budding should be performed in order to manage early CRC properly.
Remarkable stability in patterns of blood-stage gene expression during episodes of non-lethal Plasmodium yoelii malaria
Authors: Cernetich-Ott Amy , Daly Thomas M , Vaidya Akhil B , Bergman Lawrence W , Burns James M
Published: August 2012

Background

Microarray studies using in vitro cultures of synchronized, blood-stagePlasmodium falciparummalaria parasites have revealed a ‘just-in-time’ cascade of gene expression with some indication that these transcriptional patterns remain stable even in the presence of external stressors. However, direct analysis of transcription inP. falciparumblood-stage parasites obtained from the blood of infected patients suggests that parasite gene expression may be modulated by factors present in the in vivo environment of the host. The aim of this study was to examine changes in gene expression of the rodent malaria parasite,Plasmodium yoelii17X, while varying the in vivo setting of replication.

Methods

UsingP. yoelii17X parasites replicating in vivo, differential gene expression in parasites isolated from individual mice, from independent infections, during ascending, peak and descending parasitaemia and in the presence and absence of host antibody responses was examined usingP. yoeliiDNA microarrays. A genome-wide analysis to identify coordinated changes in groups of genes associated with specific biological pathways was a primary focus, although an analysis of the expression patterns of two multi-gene families inP. yoelii, theyirandpyst-afamilies, was also completed.

Results

Across experimental conditions, transcription was surprisingly stable with little evidence for distinct transcriptional states or for consistent changes in specific pathways. Differential gene expression was greatest when comparing differences due to parasite load and/or host cell availability. However, the number of differentially expressed genes was generally low. Of genes that were differentially expressed, many involved biologically diverse pathways. There was little to no differential expression of members of theyirandpyst-amultigene families that encode polymorphic proteins associated with the membrane of infected erythrocytes. However, a relatively large number of these genes were expressed during blood-stage infection regardless of experimental condition.

Conclusions

Taken together, these results indicate that 1)P. yoeliigene expression remains stable in the presence of a changing host environment, and 2) concurrent expression of a large number of the polymorphicyirandpyst-agenes, rather than differential expression in response to specific host factors, may in itself limit the effectiveness of host immune responses.