Search results for "CASS"

Evaluation of P-glycoprotein (abcb1a/b) modulation of [18F]fallypride in MicroPET imaging studies

2012

[(18)F]Fallypride ([(18)F]FP) is an important and routinely used D2/D3 antagonist for quantitative imaging of dopaminergic neurotransmission in vivo. Recently it was shown that the brain uptake of the structurally related [(11)C]raclopride is modulated by P-glycoprotein (P-gp), an important efflux transporter at the blood-brain barrier. The purpose of this study was to determine whether the brain uptake of [(18)F]FP is influenced by P-gp. For examination of this possible modulation microPET studies were performed in a rat and a mouse model. Hence, [(18)F]FP was applied to Sprague Dawley rats, half of them being treated with the P-gp inhibitor cyclosporine A (CsA). In a second experimental s…

Synthesis and evaluation of (S)-2-(2-[18F]fluoroethoxy)-4-([3-methyl-1-(2-piperidin-1-yl-phenyl)-butyl-carbamoyl]-methyl)-benzoic acid ([18F]repaglin…

2004

18F-labeled non-sulfonylurea hypoglycemic agent (S)-2-(2-[(18)F]fluoroethoxy)-4-((3-methyl-1-(2-piperidin-1-yl-phenyl)-butylcarbamoyl)-methyl)-benzoic acid ([(18)F]repaglinide), a derivative of the sulfonylurea-receptor (SUR) ligand repaglinide, was synthesized as a potential tracer for the non-invasive investigation of the sulfonylurea 1 receptor status of pancreatic beta-cells by positron emission tomography (PET) in the context of type 1 and type 2 diabetes. [(18)F]Repaglinide could be obtained in an overall radiochemical yield (RCY) of 20% after 135 min with a radiochemical purity higher than 98% applying the secondary labeling precursor 2-[(18)F]fluoroethyltosylate. Specific activity w…

P-Glycoprotein Influence on the Brain Uptake of a 5-HT2A Ligand: [18F]MH.MZ

2010

<i>Background/Aims:</i> The serotonergic system, especially the 5-HT<sub>2A</sub> receptor, is involved in various diseases and conditions. We have recently developed a new [<sup>18</sup>F]-5-HT<sub>2A</sub> receptor ligand using an analogue, MDL 100907, as a basis for molecular imaging with positron emission tomography. This tracer, [<sup>18</sup>F]MH.MZ, has been shown to be an adequate tool to visualize the 5-HT<sub>2A</sub> receptors in vivo. However, [<sup>18</sup>F]altanserin, similar in chemical structure, is a substrate of efflux transporters, such as P-glycoprotein (P-gp), of the blood-brain barrier…

Identification of P-glycoprotein substrates and inhibitors among psychoactive compounds--implications for pharmacokinetics of selected substrates.

2004

Abstract The pharmacokinetics of antipsychotic drugs has become an integral part in understanding their pharmacodynamic activity and clinical effects. In addition to metabolism aspects, carrier-mediated transport, particularly secretion by ABC transporters, has been discussed as potentially relevant for this group of therapeutics. In this study, the psychoactive compounds perphenazine, flupentixol, domperidone, desmethyl clozapine, haloperidol, fluphenazine, fluvoxamine, olanzapine, levome-promazine, perazine, desmethyl perazine, clozapine, quetiapine and amisulpride were characterized in terms of P-glycoprotein (P-gp) affinity and transport. Experimental methods involved a radioligand disp…

Un viaje de ida y vuelta al otro mundo. El Cabaret del Diavolo de Gino Gori y Fortunato Depero en Roma (1922-1925)

2023

The Roman cabarets linked to Futurism were meeting places where the programme of the manifesto Ricostruzione futurista dell’universo was applied. Following the experiences of Bragaglia and Marchi at the Circolo delle Cronache d’Attualità and the setting by Giacomo Balla at the Bal Tic Tac, the entrepreneur and poet Gino Gori commissioned Fortunato Depero to decorate the Cabaret del Diavolo. Based on Dante’s Commedia, Depero would create an integral design of three spaces that configured an allegorical inverted reading of the Florentine poet’s journey to the afterworld. Its originality and careful advertising made the cabaret one of the representative spaces of the Roman nightlife which, des…

L'INDIRIZZO PAIDEUTICO DI UN MAESTRO DELL'ANTICO MONACHESIMO: AD QUARTUM ... PERVENIRE (CASSIAN., CONL., 3,10)

2008

Nella paideia monastica di Giovanni Cassiano, cui si è richiamato nel tardo impero romano tutto il monachesimo occidentale e in particolare quello gallico e provenzale (S. Pricoco, V. Messana), si rintracciano e si focalizzano quattro gradi o momenti, fasi o tappe di progresso nel cammino di perfezione, tutti e quattro rispettivamente e parallelamente fondati sui quattro sensi della Scrittura (historia, tropologia, allegoria, anagogia), e ancorati ai quattro tipi dell''eucologia paolina di 1Tim. 2,1 (obsecratio, oratio, postulatio, gratiarum actio).

Da Girolamo Cassar a Stefano Ittar. Architettura e costruzione a Malta in età moderna.

Identification of sequences in the human peptide transporter subunit TAP1 required for transporter associated with antigen processing (TAP) function

2001

The heterodimeric peptide transporter associated with antigen processing (TAP) consisting of the subunits TAP1 and TAP2 mediates the transport of cytosolic peptides into the lumen of the endoplasmic reticulum (ER). In order to accurately define domains required for peptide transporter function, a molecular approach based on the construction of a panel of human TAP1 mutants and their expression in TAP1(-/-) cells was employed. The characteristics and biological activity of the various TAP1 mutants were determined, and compared to that of wild-type TAP1 and TAP1(-/-) control cells. All mutant TAP1 proteins were localized in the ER and were capable of forming complexes with the TAP2 subunit. H…

Cholesterol and Amyloid-β: Evidence for a Cross-Talk between Astrocytes and Neuronal Cells.

2011

Accumulating data supports the concept that alterations of cholesterol metabolism might influence the development of Alzheimer's disease (AD), a neurodegenerative disorder characterized by progressive accumulation of amyloid-β (Aβ) peptides in the brain. Changes in the neuronal production of Aβ have been described as a function of cholesterol levels, thus suggesting a causal link between cholesterol homeostasis dysregulation and AD pathogenesis. Under physiological conditions, cholesterol uptake in the brain is efficiently prevented by the blood-brain barrier, and mature neurons are thought to rely on glial cells for their cholesterol supply. In the present study, we tested the hypothesis t…

2006

During the past years, we and others discovered a series of human ATP-binding cassette (ABC) transporters, now referred to as ABC A-subfamily transporters. Recently, a novel testis-specific ABC A transporter, Abca17, has been cloned in rodent. In this study, we report the identification and characterization of the human ortholog of rodent Abca17. The novel human ABC A-transporter gene on chromosome 16p13.3 is ubiquitously expressed with highest expression in glandular tissues and the heart. The new ABC transporter gene exhibits striking nucleotide sequence homology with the recently cloned mouse (58%) and rat Abca17 (51%), respectively, and is located in the syntenic region of mouse Abca17 …