Search results for "porter"

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…

The DAT ligand [(18)F]PR17.MZ mirrors the in vivo pharmacokinetic profile of [(11)C]cocaine with significantly improved monoamine transporter selecti…

2010

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…

(18) F-labeled folic acid derivatives for imaging of the folate receptor via positron emission tomography.

2013

The folate receptor (FR) is already known as a proven target in diagnostics and therapy of cancer. Furthermore, the FR is involved in inflammatory and autoimmune diseases. The major advantage as a valuable target is its strongly limited expression in healthy tissues. Over the past two decades, several folic acid-based radiopharmaceuticals addressing the FR have been developed, and some of them show great potential for applications in clinical routine. However, most of these radiofolates were developed for single photon emission computed tomography imaging, and only a few can be used for positron emission tomography (PET) imaging. The development of suitable (18) F-labeled derivatives for PE…

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…

Mind the gap—deficits in our knowledge of aspects impacting the bioavailability of phytochemicals and their metabolites—a position paper focusing on …

2015

This is an open access article under the terms of the Creative Commons Attribution-Non-Commercial-NoDerivs Licence.-- et al.

Agricultural Value Chain for Food Security: Challenges and Opportunities from SDG2

2019

The objective of this text is to provide non-economists with an analytical tool by which to understand various aspects of how contemporary agriculture and agribusiness systems function. It will begin by outlining Porter’s value chain paradigm and Porter’s value system. Thereafter, there will follow an overview of the meaning of agricultural value chain (AVC) and its main features.

Max Porter: Francis Baconin kuolema

2022

Arvio teoksesta Max Porter: Francis Baconin kuolema. Suomentanut Irmeli Ruuska. WSOY. Helsinki. 2022. 68 s. Max Porter: The Death of Francis Bacon. Faber & Faber Ltd. London. 2021. 74 p. nonPeerReviewed

Computing Metal-Binding Proteins for Therapeutic Benefit

2021

Over one third of biomolecules rely on metal ions to exert their cellular functions. Metal ions can play a structural role by stabilizing the structure of biomolecules, a functional role by promoting a wide variety of biochemical reactions, and a regulatory role by acting as messengers upon binding to proteins regulating cellular metal-homeostasis. These diverse roles in biology ascribe critical implications to metal-binding proteins in the onset of many diseases. Hence, it is of utmost importance to exhaustively unlock the different mechanistic facets of metal-binding proteins and to harness this knowledge to rationally devise novel therapeutic strategies to prevent or cure pathological st…