Search results for "Positron-Emission Tomography"
showing 10 items of 228 documents
Higher Free Fatty Acid Uptake in Visceral Than in Abdominal Subcutaneous Fat Tissue in Men
2010
Visceral adipose tissue has been shown to have high lipolytic activity. The aim of this study was to examine whether free fatty acid (FFA) uptake into visceral adipose tissue is enhanced compared to abdominal subcutaneous tissue in vivo. Abdominal adipose tissue FFA uptake was measured using positron emission tomography (PET) and [F-18]-labeled 6-thia-hepta-decanoic acid ([F-18]FTHA) and fat masses using magnetic resonance imaging (MRI) in 18 healthy young adult males. We found that FFA uptake was 30% higher in visceral compared to subcutaneous adipose tissue (0.0025 +/- 0.0018 vs. 0.0020 +/- 0.0016 mu mol/g/min, P = 0.005). Visceral and subcutaneous adipose tissue FFA uptakes were strongly…
Fate of Linear and Branched Polyether-Lipids In Vivo in Comparison to Their Liposomal Formulations by 18F-Radiolabeling and Positron Emission Tomogra…
2015
In this study, linear poly(ethylene glycol) (PEG) and novel linear-hyperbranched, amphiphilic polyglycerol (hbPG) polymers with cholesterol (Ch) as a lipid anchor moiety were radiolabeled with fluorine-18 via copper-catalyzed click chemistry. In vivo investigations via positron emission tomography (PET) and ex vivo biodistribution in mice were conducted. A systematic comparison to the liposomal formulations with and without the polymers with respect to their initial pharmacokinetic properties during the first hour was carried out, revealing remarkable differences. Additionally, cholesterol was directly labeled with fluorine-18 and examined likewise. Both polymers, Ch-PEG27-CH2-triazole-TEG-…
Ex vivo and in vivo evaluation of [18F]PR04.MZ in rodents: a selective dopamine transporter imaging agent.
2009
N-4-Fluorobut-2-yn-1-yl-2beta-carbomethoxy-3beta-phenyltropane (PR04.MZ) has been developed as dopamine transporter (DAT) ligand for molecular imaging. It contains a terminally fluorinated, conformationally constrained nitrogen substituent that is well suited for the introduction of fluorine-18. The present report describes the pharmacological characterisation of [18F]PR04.MZ. The ligand shows an IC50 value of 2 nM against human DAT, whereas the IC50 value against human serotonin transporter and human noradrenalin transporter are lower (110 nM and 22 nM, respectively). Furthermore, its ex vivo organ distribution, its binding profile in the rat brain and reversibility of binding were examine…
In vivo biodistribution of amino-functionalized ceria nanoparticles in rats using positron emission tomography.
2012
A variety of nanoparticles have been proposed for several biomedical applications. To gauge the therapeutic potential of these nanoparticles, in vivo biodistribution is essential and mandatory. In the present study, ceria nanoparticles (5 nm average particle size) were labeled with F-18 to study their in vivo biodistribution in rats by positron emission tomography (PET). The F-18 isotope was anchored by reaction of N-succinimidyl 4-[F-18]fluorobenzoate (F-18-SFB) with a modified nanoparticle surface obtained by silylation with 3-aminopropylsilyl. Radiolabeled ceria nanoparticles accumulated mainly in lungs, spleen, and liver. Metabolic products of the radiolabeled nanoparticulate material w…
Pattern of occult nodal relapse diagnosed with 18F-fluoro-choline PET/CT in prostate cancer patients with biochemical failure after prostate-only rad…
2014
Abstract Introduction The purpose of this study was to describe the pattern of nodal relapse with 18 F-fluoro-choline (FCH) Positron Emission Tomography/Computerized Tomography (PET/CT) in prostate cancer patients after radiotherapy. Materials and methods Eighty-three patients had a FCH PET/CT at time of biochemical failure. Of 65 patients with positive findings, 33 had positive nodes. This analysis included 31 patients who had undergone prior prostate-only radiotherapy with or without a prior radical prostatectomy. Each FCH positive node was assigned to a lymph node station with respect to the CTV defined by the RTOG guidelines (CTV RTOG ). 3D mapping was performed after each node was manu…
Genetic linkage of autosomal dominant progressive supranuclear palsy to 1q31.1
2005
Progressive supranuclear palsy (PSP) is a disorder of unknown pathogenesis. Familial clusters of PSP have been reported related to mutations of protein tau. We report the linkage of a large Spanish family with typical autosomal dominant PSP to a new locus in chromosome 1. Four members of this family had typical PSP, confirmed by neuropathology in one case. At least five ancestors had similar disease. Other members of the family have incomplete phenotypes. The power of the linkage analysis was increased by detecting presymptomatic individuals with 18F-fluoro-dopa and 18F-deoxyglucose positron emission tomography. We screened the human genome with 340 polymorphic markers and we enriched the a…
Blood constituents trigger brain swelling, tissue death, and reduction of glucose metabolism early after acute subdural hematoma in rats
2009
Outcome from acute subdural hematoma is often worse than would be expected from the pure increase of intracranial volume by bleeding. The aim was to test whether volume-independent pathomechanisms aggravate damage by comparing the effects of blood infusion with those of an inert fluid, paraffin oil, on intracranial pressure (ICP), cerebral perfusion pressure (CPP), local cerebral blood flow (CBF), edema formation, glucose metabolism ([18F]-deoxyglucose, MicroPET), and histological outcome. Rats were injured by subdural infusion of 300 μL venous blood or paraffin. ICP, CPP, and CBF changes, assessed during the first 30 mins after injury, were not different between the injury groups at most …
Choice of reference area in studies of Alzheimer's disease using positron emission tomography with fluorodeoxyglucose-F18
2007
At present, there is still no consensus on the choice of the reference area in positron emission tomography (PET) studies of Alzheimer's disease (AD). In this study, PET scans with fluorodeoxyglucose-F18 were carried out in the following groups of subjects: 47 patients with probable AD, 8 patients with mild cognitive impairment, and 15 age-similar healthy subjects. Scans normalized to the cerebral global mean (CGM), cerebellum (CBL), and the primary sensorimotor cortex (SMC). We evaluated the effect of the different count normalization procedures on the accuracy of (18)F-FDG PET to detect AD-specific metabolic abnormalities (voxel-based group comparison) and to differentiate between patient…
Physical Activity and Amyloid-β Brain Levels in Elderly Adults with Intact Cognition and Mild Cognitive Impairment
2015
Objectives To examine the associations between amyloid-β brain deposition and physical activity (PA) in elderly adults without dementia and to investigate whether the association has a dose-response relationship. Design Cross-sectional study. Setting French community-dwelling people. Participants Elderly adults with normal or mildly impaired cognition (mean age 74.7 ± 4.2; 60.4% female) with available information on current self-reported PA and amyloid-β brain deposition measured using positron emission tomography (PET) using the PET-ligand florbetapir F 18 (n = 268). Measurements A standardized uptake value ratio (SUVR) was obtained for each subject. Participants were divided according to …
Validating the DemTect with 18-Fluoro-2-Deoxy-Glucose Positron Emission Tomography as a Sensitive Neuropsychological Screening Test for Early Alzheim…
2005
<i>Objectives:</i> The first study to validate the diagnostic value of the DemTect, a short neuropsychological screening test for dementia (8–10 min), using 18-fluoro-2-deoxy-glucose positron emission tomography (FDG-PET) in patients of a memory clinic. <i>Methods:</i> DemTect results were compared to the clinical diagnosis and to FDG-PET as a reference method for the early in vivo detection of Alzheimer’s disease (AD). <i>Results:</i> 38 patients (age 65.2 ± 9.8 years, 16 men, 22 women) were investigated using clinical standard examination, FDG-PET, and cranial magnetic resonance imaging. According to NINCDS-ADRDA and Petersen’s criteria, 18 patients had…