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magnetic resonance

Yan Li, Mourad Harir, Marianna Lucio, Michael Gonsior, Boris P Koch, Philippe Schmitt-Kopplin, Norbert Hertkorn
Deciphering the molecular codes of dissolved organic matter (DOM) improves our understanding of its role in the global element cycles and its active involvement in ecosystem services. This study demonstrates comprehensive characterization of DOM by an initial polarity-based stepwise solid phase extraction (SPE) with single methanol elution of the cartridges, but separate collection of equal aliquots of eluate. The reduction of molecular complexity in the individual DOM fractions attenuates intermolecular interactions and substantially increases the disposable resolution of any structure selective characterization...
October 14, 2016: Water Research
Påvel G Lindberg, Maxime Térémetz, Sylvain Charron, Oussama Kebir, Agathe Saby, Narjes Bendjemaa, Stéphanie Lion, Benoît Crépon, Raphaël Gaillard, Catherine Oppenheim, Marie-Odile Krebs, Isabelle Amado
Inhibition is considered a key mechanism in schizophrenia. Short-latency intracortical inhibition (SICI) in the motor cortex is reduced in schizophrenia and is considered to reflect locally deficient γ-aminobutyric acid (GABA)-ergic modulation. However, it remains unclear how SICI is modulated during motor inhibition and how it relates to neural processing in other cortical areas. Here we studied motor inhibition Stop signal task (SST) in stabilized patients with schizophrenia (N = 28), healthy siblings (N = 21) and healthy controls (n = 31) matched in general cognitive status and educational level...
September 30, 2016: Cortex; a Journal Devoted to the Study of the Nervous System and Behavior
Hiroko Kubo, Masahito Nakataki, Satsuki Sumitani, Jun-Ichi Iga, Shusuke Numata, Naomi Kameoka, Shin-Ya Watanabe, Hidehiro Umehara, Makoto Kinoshita, Masatoshi Inoshita, Mai Tamaru, Masashi Ohta, Chiaki Nakayama-Yamauchi, Yasuhiro Funakoshi, Masafumi Harada, Tetsuro Ohmori
BACKGROUND: Previous studies of patients with bipolar disorder (BD) using magnetic resonance spectroscopy (MRS) have shown neurophysiological abnormalities related to the glutamate (Glu)-glutamine (Gln) cycle, membrane turnover, and neuronal integrity, although the results were neither consistent nor conclusive. Recently it has been reported the Gln/Glu ratio is the most useful index, quantifying neuronal-glial interactions and the balance of glutamatergic metabolites In this MRS study, we elucidated the abnormalities of metabolites in a larger sample of patients with BD with a high-field MRI system...
October 8, 2016: Journal of Affective Disorders
Allison C Nugent, Bruce Luber, Frederick W Carver, Stephen E Robinson, Richard Coppola, Carlos A Zarate
Recently, independent components analysis (ICA) of resting state magnetoencephalography (MEG) recordings has revealed resting state networks (RSNs) that exhibit fluctuations of band-limited power envelopes. Most of the work in this area has concentrated on networks derived from the power envelope of beta bandpass-filtered data. Although research has demonstrated that most networks show maximal correlation in the beta band, little is known about how spatial patterns of correlations may differ across frequencies...
October 22, 2016: Human Brain Mapping
Nicole Groh, Christian Seutter von Loetzen, Brinda Subbarayal, Christian Möbs, Lothar Vogel, Andreas Hoffmann, Kay Fötisch, Anna Koutsouridou, Stefanie Randow, Elke Völker, Andreas Reuter, Paul Rösch, Stefan Vieths, Wolfgang Pfützner, Barbara Bohle, Dirk Schiller
BACKGROUND: Allergen-specific immunotherapy (AIT) with birch pollen generates Bet v 1-specific immunoglobulin (Ig)G4 which blocks IgE-mediated hypersensitivity mechanisms. Whether IgG4 specific for Bet v1a competes with IgE for identical epitopes or whether novel epitope specificities of IgG4 antibodies are developed is under debate. OBJECTIVE: We sought to analyze the epitope specificities of IgE and IgG4 antibodies from sera of patients who received AIT. METHODS: 15 sera of patients (13/15 received AIT) with Bet v 1a-specific IgE and IgG4 were analyzed...
October 22, 2016: Clinical and Experimental Allergy: Journal of the British Society for Allergy and Clinical Immunology
Bertram J Wilm, Christoph Barmet, Simon Gross, Lars Kasper, S Johanna Vannesjo, Max Haeberlin, Benjamin E Dietrich, David O Brunner, Thomas Schmid, Klaas P Pruessmann
PURPOSE: The purpose of this work was to improve the quality of single-shot spiral MRI and demonstrate its application for diffusion-weighted imaging. METHODS: Image formation is based on an expanded encoding model that accounts for dynamic magnetic fields up to third order in space, nonuniform static B0 , and coil sensitivity encoding. The encoding model is determined by B0 mapping, sensitivity mapping, and concurrent field monitoring. Reconstruction is performed by iterative inversion of the expanded signal equations...
October 21, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
M Arcan Ertürk, Xiaoping Wu, Yiğitcan Eryaman, Pierre-François Van de Moortele, Edward J Auerbach, Russell L Lagore, Lance DelaBarre, J Thomas Vaughan, Kâmil Uğurbil, Gregor Adriany, Gregory J Metzger
PURPOSE: To explore the potential of performing body imaging at 10.5 Tesla (T) compared with 7.0T through evaluating the transmit/receive performance of similarly configured dipole antenna arrays. METHODS: Fractionated dipole antenna elements for 10.5T body imaging were designed and evaluated using numerical simulations. Transmit performance of antenna arrays inside the prostate, kidneys and heart were investigated and compared with those at 7.0T using both phase-only radiofrequency (RF) shimming and multi-spoke pulses...
October 21, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Hong Shang, Subramaniam Sukumar, Cornelius von Morze, Robert A Bok, Irene Marco-Rius, Adam Kerr, Galen D Reed, Eugene Milshteyn, Michael A Ohliger, John Kurhanewicz, Peder E Z Larson, John M Pauly, Daniel B Vigneron
PURPOSE: Balanced steady-state free precession (bSSFP) sequences can provide superior signal-to-noise ratio efficiency for hyperpolarized (HP) carbon-13 ((13) C) magnetic resonance imaging by efficiently utilizing the nonrecoverable magnetization, but managing their spectral response is challenging in the context of metabolic imaging. A new spectrally selective bSSFP sequence was developed for fast imaging of multiple HP (13) C metabolites with high spatiotemporal resolution. THEORY AND METHODS: This novel approach for bSSFP spectral selectivity incorporates optimized short-duration spectrally selective radiofrequency pulses within a bSSFP pulse train and a carefully chosen repetition time to avoid banding artifacts...
October 21, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Stephen F Cauley, Kawin Setsompop, Berkin Bilgic, Himanshu Bhat, Borjan Gagoski, Lawrence L Wald
PURPOSE: Fast MRI acquisitions often rely on efficient traversal of k-space and hardware limitations, or other physical effects can cause the k-space trajectory to deviate from a theoretical path in a manner dependent on the image prescription and protocol parameters. Additional measurements or generalized calibrations are typically needed to characterize the discrepancies. We propose an autocalibrated technique to determine these discrepancies. METHODS: A joint optimization is used to estimate the trajectory simultaneously with the parallel imaging reconstruction, without the need for additional measurements...
October 21, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Michael Buchfelder, Sven-Martin Schlaffer
PURPOSE: Surgical extraction of as much tumour mass as possible is considered the first step of treatment in acromegaly in many centers. In this article the potential benefits, disadvantages and limitations of operative acromegaly treatment are reviewed. METHODS: Pertinent literature was selected to provide a review covering current indications, techniques and results of operations for acromegaly. RESULTS: The rapid reduction of tumour volume is an asset of surgery...
October 21, 2016: Pituitary
Daniela Mier, Sarah Eisenacher, Franziska Rausch, Susanne Englisch, Martin Fungisai Gerchen, Vera Zamoscik, Andreas Meyer-Lindenberg, Mathias Zink, Peter Kirsch
Schizophrenia is associated with significant impairments in social cognition. These impairments have been shown to go along with altered activation of the posterior superior temporal sulcus (pSTS). However, studies that investigate connectivity of pSTS during social cognition in schizophrenia are sparse. Twenty-two patients with schizophrenia and 22 matched healthy controls completed a social-cognitive task for functional magnetic resonance imaging that allows the investigation of affective Theory of Mind (ToM), emotion recognition and the processing of neutral facial expressions...
October 21, 2016: European Archives of Psychiatry and Clinical Neuroscience
Gabor Nagy, Viktoria Baksa, Alexandra Kiss, Melinda Turani, Gaspar Banfalvi
The toxicity of gadolinium is reduced by chelating agents that render this heavy metal into contrast complexes used for medical magnetic resonance imaging. However, the dissociation of gadolinium chelates is known to generate Gd(3+) ions, the cellular toxicity of which has not been tested in details. The cytotoxic effects of Gd(III) ions were evaluated by monitoring the proliferation, measuring the cellular motility and following chromatin changes in various cell lines upon Gd(3+) treatment. Measurements applied long-term scanning microscopy and a perfusion platform that replaced the medium with test solutions, bypassed physical contact with the cell culture during experiments, and provided uninterrupted high time-resolution time-lapse photomicrography for an extended period of time...
October 22, 2016: Apoptosis: An International Journal on Programmed Cell Death
Xintao Hu, Lei Guo, Junwei Han, Christine Cong Guo
Neural discrimination of auditory intensity is one of the fundamental questions in human auditory perception. Human neuroimaging studies have demonstrated specific neural activations during intensity discrimination tasks. The detailed functional anatomy, however, remains elusive. Most of the existing studies examined the entire auditory cortex as a whole, neglecting the potential functional differentiation within the auditory cortex. Moreover, these previous results based on controlled auditory stimuli might not necessarily extend to the neural mechanism of natural auditory processing...
October 21, 2016: Brain Structure & Function
A Achtnich, S Rosslenbroich, K Beitzel, A B Imhoff, W Petersen
OBJECTIVE: Arthroscopic assisted suture anchor refixation combined with microfracturing of the femoral ACL insertion zone in cases of acute proximal anterior cruciate ligament (ACL) rupture to restore anatomical and biomechanical properties of the native ACL. INDICATIONS: Acute proximal ACL rupture/avulsion, multiligament injury of the knee CONTRAINDICATIONS: Chronic (>6 weeks) proximal ACL rupture, intraligamentary rupture, as well as previous ACL surgery. SURGICAL TECHNIQUE: Arthroscopic examination of the knee joint, debridement of the femoral insertion zone, examination of the ligament quality by a probe, insertion of a curved lasso through the ACL to place the sutures and use of a drill guide to place the anchor in the middle of the femoral ACL insertion...
October 21, 2016: Operative Orthopädie und Traumatologie
Raj Kumar Sharma, Kumudesh Mishra, Alvina Farooqui, Anu Behari, Vinay Kumar Kapoor, Neeraj Sinha
OBJECTIVE AND DESIGN: We present in this article (1)H nuclear magnetic resonance (NMR)-based metabolic approach to screen the serum metabolic alterations in human gallbladder inflammation with chronic cholecystitis (CC). MATERIAL/METHODS: Total of 71 human serum samples was divided into two groups, (n = 41, CC) and (n = 30 control). (1)H NMR metabolic profiling was carried out for investigation of metabolic alterations. Multivariate statistical analysis was applied for pattern recognition and identification of metabolites playing crucial role in gallbladder inflammation...
October 21, 2016: Inflammation Research: Official Journal of the European Histamine Research Society ... [et Al.]
Kelsey L Shnaekel, Michael P Wendel, Nader Z Rabie, Everett F Magann
Objective: The aim of this review was to describe the risk factors, clinical and radiographic criteria, and management of this rare complication of pregnancy. Methods: A PubMed, Web of Science, and CINAHL search was undertaken with no limitations on the number of years searched. Results: There were 60 articles identified, with 53 articles being the basis of this review. Multiple risk factors have been suggested in the literature including retroverted uterus in the first trimester, deep sacral concavity with an overlying sacral promontory, endometriosis, previous abdominal or pelvic surgery, pelvic or uterine adhesions, ovarian cysts, leiomyomas, multifetal gestation, uterine anomalies, uterine prolapse, and uterine incarceration in a prior pregnancy...
October 2016: Obstetrical & Gynecological Survey
C Yong, Y M Teo, K Jeevesh
OBJECTIVE: To evaluate the performance of contrastenhanced ultrasound (CEUS) in the risk stratification of indeterminate renal lesions picked up incidentally on abdominal imaging, in patients with renal impairment. METHODS: A retrospective study was performed of nonconsecutive patients who underwent CEUS at our tertiary care centre for indeterminate renal lesions between March 2010 and September 2014. A total of 63 patients with 74 nodules were assessed with CEUS and stratified into either benign (Bosniak I, II, IIF) or suspicious for malignancy (Bosniak III, IV or hypervascular solid lesions)...
August 2016: Medical Journal of Malaysia
Ahmad Masri, Vidyasagar Kalahasti, Lars G Svensson, Eric E Roselli, Douglas Johnston, Donald Hammer, Paul Schoenhagen, Brian P Griffin, Milind Y Desai
BACKGROUND: -In patients with a dilated proximal ascending aorta and trileaflet aortic valve (TAV), we sought to assess a) factors independently associated with increased long-term mortality and b) the incremental prognostic utility of indexing aortic root to patient height. METHODS: -We studied consecutive patients with a dilated aortic root (≥4 cm) that underwent echocardiography and gated contrast-enhanced thoracic aortic computed tomography or magnetic resonance angiography between 2003-2007...
October 21, 2016: Circulation
Per Martin Arvidsson, Johannes Töger, Marcus Carlsson, Katarina Steding-Ehrenborg, Gianni Pedrizzetti, Einar Heiberg, Hakan Arheden
Intracardiac blood flow is driven by hemodynamic forces that are exchanged between the blood and myocardium. Previous studies have been limited to 2D measurements or investigated only LV forces. Right ventricular forces and their mechanistic contribution to asymmetric redirection of flow in the RV have not been measured. We therefore aimed to quantify three-dimensional hemodynamic forces in both ventricles in a cohort of healthy subjects, using magnetic resonance imaging 4D flow measurements. 25 controls,14 elite endurance athletes, and two patients with left ventricular dyssynchrony were included...
October 21, 2016: American Journal of Physiology. Heart and Circulatory Physiology
Shigemiki Omiya, Yosuke Omori, Manabu Taneike, Andrea Protti, Osamu Yamaguchi, Shizuo Akira, Ajay M Shah, Kazuhiko Nishida, Kinya Otsu
We have reported that the Toll-like receptor 9 (TLR9) signaling pathway plays an important role in the development of pressure overload-induced inflammatory responses and heart failure. However, its role in cardiac remodeling after myocardial infarction has not been elucidated.TLR9-deficient and control C57Bl/6 wild-type mice were subjected to left coronary artery ligation. The survival rate 14 days post-operation was significantly lower in TLR9-deficient mice than that in wild-type mice with evidence of cardiac rupture in all dead mice...
October 21, 2016: American Journal of Physiology. Heart and Circulatory Physiology
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