Search results for "Contrast"
showing 10 items of 1162 documents
Technology Insight: confocal laser endoscopy for in vivo diagnosis of colorectal cancer
2006
Recent studies on a novel technology, denoted confocal laser endomicroscopy (CLE), have altered thinking about the possibilities of endoscopy in the diagnosis and treatment of colorectal cancer. CLE is a new endoscopic tool that allows in vivo histology at subcellular resolution during ongoing endoscopy, and permits subsurface imaging of normal and neoplastic human mucosa. This new technique has unequivocal major implications for the diagnosis and clinical management of patients scheduled for screening or surveillance colonoscopy for colorectal cancer. For instance, CLE allows immediate diagnosis of colonic neoplasias, and the detection of neoplastic cells helps to target endoscopic interve…
Neuronal and BBB damage induced by sera from patients with secondary progressive multiple sclerosis.
2009
An important component of the pathogenic process of multiple sclerosis (MS) is the blood-brain barrier (BBB) damage. We recently set an in vitro model of BBB, based on a three-cell-type co-culture system, in which rat neurons and astrocytes synergistically induce brain capillary endothelial cells to form a monolayer with permeability properties resembling those of the physiological BBB. Herein we report that the serum from patients with secondary progressive multiple sclerosis (SPMS) has a damaging effect on isolated neurons. This finding suggests that neuronal damaging in MS could be a primary event and not only secondary to myelin damage, as generally assumed. SPMS serum affects the perme…
Perspectives in Clinical Hemorheology and Microcirculation: Review of the Conference of the German Society for Clinical Microcirculation and Hemorheo…
2011
During the 29th conference of the German Society for Clinical Microcirculation and Hemorheology – held in the Freie Universitat Berlin a broad range of different topics of experimental and clinical studies in the field were presented. A special spotlight was dedicated to the Conference President’s (Prof. Dr. J. Plendl, Head of the Department of Veterinary Anatomy) scientific area “Anatomical and Experimental Microcirculation” [5, 6, 9, 13]. Of special interest were the angiogenetic studies: Examinations of the influence of PDGF-BB on adipose-tissue derived stem cells and how these influence angiogenesis [9] and the angiogenesis and healing with non-shrinking, fast degradable PLGA/CaP scaffo…
Rectal cancer: Dynamic contrast-enhanced MRI correlates with lymph node status and epidermal growth factor receptor expression
2013
Purpose To evaluate correlations between dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and clinicopathologic data as well as immunostaining of the markers of angiogenesis epidermal growth factor receptor (EGFR) and CXC-motif chemokine receptor 4 (CXCR4) in patients with rectal cancer. Materials and Methods Presurgical DCE-MRI was performed in 41 patients according to a standardized protocol. Two quantitative parameters (k21, A) were derived from a pharmacokinetic two-compartment model, and one semiquantitative parameter (TTP) was assessed. Standardized surgery and histopathologic examinations were performed in all patients. Immunostaining for EGFR and CXCR4 was performed an…
Modified lipoproteins as contrast agents for imaging of atherosclerosis.
2007
The ability to detect and characterize atherosclerosis with targeted contrast agents may enable initiation of therapy for atherosclerotic lesions prior to becoming symptomatic. Since lipoproteins such as high-density lipoprotein (HDL) and low-density lipoprotein (LDL) play a critical role in the regulation of plaque biology through the transport of lipids into and out of atherosclerotic lesions, modifying HDL and LDL with radioisotopes for nuclear imaging, chelates for magnetic resonance imaging (MRI) or other possible contrast agents for computed tomography imaging techniques may aid in the detection and characterization of atherosclerosis. This review focuses on the literature employing l…
Angiogenesis of cancer of the cervix. Contrast-enhanced dynamic MRT, histological quantification of capillary density and lymph system infiltration
1998
Purpose: It was the aim of this project to examine (i) the relationships between contrast-enhanced dynamic MR imaging derived characteristics and histologic microvessel density counts – a recognized surrogate of tumor angiogenesis – from tumors in patients with primary or recurrent cancer of the uterine cervix, and (ii) to correlate these parameters with lymphatic involvement (i. e. lymphatic channels) to assess tumorbiological aggressiveness in terms of lymphatic spread. Materials and methods: Pharmacokinetic MR imaging parameters (amplitude A, exchange rate constant k 21) were derived from contrast-enhanced dynamic MR imaging in thirty-three patients with biopsy proven cancer of the uteri…
2021 European Thyroid Association Guidelines for the Management of Iodine-Based Contrast Media-Induced Thyroid Dysfunction
2021
Given the fact that a large number of radiological examinations using iodine-based contrast media (ICM) are performed in everyday practice, clinicians should be aware of potential ICM-induced thyroid dysfunction (TD). ICM can induce hyperthyroidism (Hyper) or hypothyroidism (Hypo) due to supraphysiological concentrations of iodine in the contrast solution. The prevalence of ICM-induced TD varies from 1 to 15%. ICM-induced Hyper is predominantly found in regions with iodine deficiency and in patients with underlying nodular goiter or latent Graves’ disease. Patients at risk for ICM-induced Hypo include those with autoimmune thyroiditis, living in areas with sufficient iodine supply. Most cas…
On the Effects of Relative Performance Feedback in a Risk Elicitation Task: Evidence From a Lab Experiment
2018
This paper experimentally investigates the influence of different non-payoff-relevant feedback regimes on motivation, competitiveness and risk-taking behaviors in a risk elicitation task. We explore four feedback regimes: private feedback, full ranking feedback, top-5 ranking feedback, and non-ranking feedback based on the median performance of peers. We found that providing relative performance feedback increases risk-taking behavior, especially when using a top-5 ranking. Feedback regimes that provide a user with rank-based feedback have adverse effects on the users' attitudes as they increase competitiveness while failing to increase intrinsic motivation and performance motivation. In co…
Sequential effects in the lexical decision task: the role of the item frequency of the previous trial.
2003
Two lexical decision experiments were conducted to determine whether there is a specific, localized influence of the item frequency of consecutive trials (i.e., first-order sequential effects) when the trials are not related to each other. Both low-frequency words and nonwords were influenced by the frequency of the precursor word (Experiment 1). In contrast, high-frequency words showed little sensitivity to the frequency of the precursor word (Experiment 2), although they showed longer reaction times for word trials preceded by a nonword trial. The presence of sequential effects in the lexical decision task suggests that participants shift their response criteria on a trial-by-trial basis.
A PERCEPTIVE-CONTRASTIVE LINGUISTICS OF SPANISH AS L2: A NEW METHODOLOGY OF CONTRASTING LANGUAGES
2014
Contrastive analysis for the acquisition of a linguistic competence between typologically related languages is a very useful and productive criterion, but in this context the aim is seeking new interpretation keys of an L2 acquisition phenomenon that can activate not only linguistic, metalinguistic and pragmatic competences, but can also allow the organization of the mental lexicon according to the dynamic laws of "cooperation" through the activation of trans-cortical neural networks. It was considered, therefore, as an useful tool, the application of certain criteria of the Perspective Linguistics to the Contrastive Linguistics of Spanish as L2, in order to create a better organized mental…