45 research outputs found

    A pilot study of transrectal endoscopic ultrasound elastography in inflammatory bowel disease

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    BACKGROUND: Using standard diagnostic algorithms it is not always possible to establish the correct phenotype of inflammatory bowel disease which is essential for therapeutical decisions. Endoscopic ultrasound elastography is a new endoscopic procedure which can differentiate the stiffness of normal and pathological tissue by ultrasound. Therefore, we aimed to investigate the role of transrectal ultrasound elastography in distiction between Crohn's disease and ulcerative colitis. ----- METHODS: A total 30 Crohn's disease, 25 ulcerative colitis, and 28 non-inflammatory bowel disease controls were included. Transrectal ultrasound elastography was performed in all patients and controls. In all ulcerative coltis patients and 80% of Crohn's disease patients endoscopy was performed to assess disease activity in the rectum. ----- RESULTS: Significant difference in rectal wall thickness and strain ratio was detected between patients with Crohn's disease and controls (p = 0.0001). CD patients with active disease had higher strain ratio than patients in remission (p = 0.02). In ulcerative colitis group a significant difference in rectal wall thickness was found between controls and patients with active disease (p = 0.03). A significant difference in rectal wall thickness (p = 0.02) and strain ratio (p = 0.0001) was detected between Crohn's disease and ulcerative colitis patient group. Crohn's disease patients with active disease had a significantly higher strain ratio compared to ulcerative colitis patients with active disease (p = 0.0001). ----- CONCLUSION: Transrectal ultrasound elastography seems to be a promising new diagnostic tool in the field of inflammatory bowel disease. Further study on a larger cohort of patients is needed to definitely assess the role of transrectal ultrasound elastography in inflammatory bowel disease

    What scans we will read: imaging instrumentation trends in clinical oncology

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    Oncological diseases account for a significant portion of the burden on public healthcare systems with associated costs driven primarily by complex and long-lasting therapies. Through the visualization of patient-specific morphology and functional-molecular pathways, cancerous tissue can be detected and characterized non- invasively, so as to provide referring oncologists with essential information to support therapy management decisions. Following the onset of stand-alone anatomical and functional imaging, we witness a push towards integrating molecular image information through various methods, including anato-metabolic imaging (e.g., PET/ CT), advanced MRI, optical or ultrasound imaging. This perspective paper highlights a number of key technological and methodological advances in imaging instrumentation related to anatomical, functional, molecular medicine and hybrid imaging, that is understood as the hardware-based combination of complementary anatomical and molecular imaging. These include novel detector technologies for ionizing radiation used in CT and nuclear medicine imaging, and novel system developments in MRI and optical as well as opto-acoustic imaging. We will also highlight new data processing methods for improved non-invasive tissue characterization. Following a general introduction to the role of imaging in oncology patient management we introduce imaging methods with well-defined clinical applications and potential for clinical translation. For each modality, we report first on the status quo and point to perceived technological and methodological advances in a subsequent status go section. Considering the breadth and dynamics of these developments, this perspective ends with a critical reflection on where the authors, with the majority of them being imaging experts with a background in physics and engineering, believe imaging methods will be in a few years from now. Overall, methodological and technological medical imaging advances are geared towards increased image contrast, the derivation of reproducible quantitative parameters, an increase in volume sensitivity and a reduction in overall examination time. To ensure full translation to the clinic, this progress in technologies and instrumentation is complemented by progress in relevant acquisition and image-processing protocols and improved data analysis. To this end, we should accept diagnostic images as “data”, and – through the wider adoption of advanced analysis, including machine learning approaches and a “big data” concept – move to the next stage of non-invasive tumor phenotyping. The scans we will be reading in 10 years from now will likely be composed of highly diverse multi- dimensional data from multiple sources, which mandate the use of advanced and interactive visualization and analysis platforms powered by Artificial Intelligence (AI) for real-time data handling by cross-specialty clinical experts with a domain knowledge that will need to go beyond that of plain imaging

    Joint action aesthetics

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    Synchronized movement is a ubiquitous feature of dance and music performance. Much research into the evolutionary origins of these cultural practices has focused on why humans perform rather than watch or listen to dance and music. In this study, we show that movement synchrony among a group of performers predicts the aesthetic appreciation of live dance performances. We developed a choreography that continuously manipulated group synchronization using a defined movement vocabulary based on arm swinging, walking and running. The choreography was performed live to four audiences, as we continuously tracked the performers’ movements, and the spectators’ affective responses. We computed dynamic synchrony among performers using cross recurrence analysis of data from wrist accelerometers, and implicit measures of arousal from spectators’ heart rates. Additionally, a subset of spectators provided continuous ratings of enjoyment and perceived synchrony using tablet computers. Granger causality analyses demonstrate predictive relationships between synchrony, enjoyment ratings and spectator arousal, if audiences form a collectively consistent positive or negative aesthetic evaluation. Controlling for the influence of overall movement acceleration and visual change, we show that dance communicates group coordination via coupled movement dynamics among a group of performers. Our findings are in line with an evolutionary function of dance–and perhaps all performing arts–in transmitting social signals between groups of people. Human movement is the common denominator of dance, music and theatre. Acknowledging the time-sensitive and immediate nature of the performer-spectator relationship, our study makes a significant step towards an aesthetics of joint actions in the performing arts

    Glycolipid transfer protein: clear structure and activity, but enigmatic function

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    Glycosphingolipids comprize a small (typically 5–10% by weight) but vital fraction of membrane lipids in eukaryotes (Holthuis et al., 2001). They provide the plasma membrane with chemical and mechanical stabilities and take part in fundamental biological processes including differentiation, cell–cell interaction, and transmembrane signaling. For these lipids, as for most lipids in general, local metabolism and selective transport are important determinants (Sprong et al., 2001). Little is known about these processes, but it is clear that several key players in the organization and control of sphingolipid composition remain to be identified. A protein purified from bovine spleen cytosol specifically transferring glycolipids was already described more than 20 years ago ([Metz and Radin, 1980] and [Radin and Metz, 1982]). An absolute specificity was found for glycolipids containing a β-linked sugar to the hydrophobic backbone (Yamada et al., 1986). Glycolipid transfer proteins (GLTPs, EC number not assigned) are water-soluble proteins of average size of 24 kDa that have been studied extensively in vitro ([Abe and Sasaki, 1985], [Abe et al., 1982], [Brown et al., 1990], [Gammon et al., 1987] and [Metz and Radin, 1982]). Very recently, their structural and in vitro functional properties were reviewed in detail (Brown and Mattjus, 2007). These proteins have been isolated from different sources ranging from spinach chloroplasts to mammalian brain, liver and kidney ([Brown et al., 1990], [Sasaki, 1985] and [Sasaki, 1990]). GLTP orthologs in fungi and plants were found to be involved in programmed cell death ([Brodersen et al., 2002], [Mattjus et al., 2003] and [Saupe et al., 1994]) but their function in mammals is largely unknown. The activity of GLTP is preserved after expression in E. coli ([Godi et al., 2004], Lin et al., 2000 X. Lin, P. Mattjus, H.M. Pike, A.J. Windebank and R.E. Brown, Cloning and expression of glycolipid transfer protein from bovine and porcine brain, J Biol Chem 275 (2000), pp. 5104–5110. Full Text via CrossRef | View Record in Scopus | Cited By in Scopus (32)[Lin et al., 2000], [Malinina et al., 2004] and [Rao et al., 2004]) allowing for detailed structure–function studies in vitro

    Regulation of Light Harvesting in the Green Alga Chlamydomonas reinhardtii: The C-Terminus of LHCSR Is the Knob of a Dimmer Switch

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    Feedback mechanisms that dissipate excess photoexcitations in light-harvesting complexes (LHCs) are necessary to avoid detrimental oxidative stress in most photosynthetic eukaryotes. Here we demonstrate the unique ability of LHCSR, a stress-related LHC from the model organism Chlamydomonas reinhardtii, to sense pH variations, reversibly tuning its conformation from a light-harvesting state to a dissipative one. This conformational change is induced exclusively by the acidification of the environment, and the magnitude of quenching is correlated to the degree of acidification of the environment. We show that this ability to respond to different pH values is missing in the related major LHCII, despite high structural homology. Via mutagenesis and spectroscopic characterization, we show that LHCSR's uniqueness relies on its peculiar C-terminus subdomain, which acts as a sensor of the lumenal pH, able to tune the quenching level of the complex. © 2013 American Chemical Society
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