1,720,995 research outputs found
Effect of chronic calcium antagonist treatment on dopamine recognition sites in rat striatum.
Glucose metabolism and serotonin receptors in the frontotemporal lobe degeneration
In patients with the frontal variant of frontotemporal lobar degeneration (fv-FTLD), behavioral abnormalities may vary from apathy with motor slowness (apathetic form) to disinhibition with agitation (disinhibited form). These clinical presentations may be related to specific regional cerebral dysfunction and to deficit in the serotoninergic system. We studied cerebral glucose uptake using 18F-fluorodeoxyglucose and positron emission tomography in 18 patients fulfilling clinical criteria for fv-FTLD and showing, respectively, an apathetic or disinhibited behavioral syndrome. In eight of these patients, we also evaluated the 5-hydroxytryptamine-2A receptor cerebral receptor distribution with [11C]MDL and positron emission tomography. We found a reduction of frontal glucose metabolism in the whole group of fv-FTLD patients. Apathetic syndrome was associated with a prevalent dorsolateral and frontal medial hypometabolism, whereas the disinhibited syndrome demonstrated a selective hypometabolism in interconnected limbic structures (the cingulate cortex, hippocampus/amygdala, and accumbens nucleus). The in vivo measurements of [11C]MDL indicated a significant reduction of 5-hydroxytryptamine- 2A receptors in orbitofrontal, frontal medial, and cingulate cortices. These 18F-fluorodeoxyglucose positron emission tomography changes can be considered as specific functional markers of the different behavioral presentations in fv-FTLD. The serotoninergic system dysfunction provides a rationale for therapeutic trials with selective serotonin reuptake inhibitors
Characterization of preclinical models of prostate cancer using PET-based molecular imaging
Transgenic adenocarcinoma of the mouse prostate (TRAMP) mice spontaneously develop hormone-dependent and hormone-independent prostate cancer (PC) that potentially resembles the human pathological condition. The aim of the study was to validate PET imaging as a reliable tool for in vivo assessment of disease biology and progression in TRAMP mice using radioligands routinely applied in clinical practice: [(18)F]FDG and [(11)C]choline. Six TRAMP mice were longitudinally evaluated starting at week 11 of age to visualize PC development and progression. The time frame and imaging pattern of PC lesions were subsequently confirmed on an additional group of five mice. PET and [(18)F]FDG allowed detection of PC lesions starting from 23 weeks of age. [(11)C]Choline was clearly taken up only by TRAMP mice carrying neuroendocrine lesions, as revealed by post-mortem histological evaluation. PET-based molecular imaging represents a state-of-the-art tool for the in vivo monitoring and metabolic characterization of PC development, progression and differentiation in the TRAMP model
Comparison of F-18-Fluoroazomycin-Arabinofuranoside and Cu-64-Diacetyl-Bis(N4-Methylthiosemicarbazone) in Preclinical Models of Cancer
Going Beyond Counting First Authors in Author Co-citation Analysis
The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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