References of "Langlois, Xavier"
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See detailUse of a beta microprobe system to measure arterial input function in PET via an arteriovenous shunt in rats
Warnock, Geoffrey ULg; Bahri, Mohamed Ali ULg; Goblet, David ULg et al

in European Journal of Nuclear Medicine and Molecular Imaging Research (2011), 1

Kinetic modeling of physiological function using imaging techniques requires the accurate measurement of the time-activity curve of the tracer in plasma, known as the arterial input function (IF). The ... [more ▼]

Kinetic modeling of physiological function using imaging techniques requires the accurate measurement of the time-activity curve of the tracer in plasma, known as the arterial input function (IF). The measurement of IF can be achieved through manual blood sampling, the use of small counting systems such as beta microprobes, or by derivation from PET images. Previous studies using beta microprobe systems to continuously measure IF have suffered from high background counts. In the present study, a light-insensitive beta microprobe with a temporal resolution of up to 1 s was used in combination with a pump-driven femoral arteriovenous shunt to measure IF in rats. The shunt apparatus was designed such that the placement of the beta microprobe was highly reproducible. The probe-derived IF was compared to that obtained from manual sampling at 5-s intervals and IF derived from a left ventricle VOI in a dynamic PET image of the heart. Probe-derived IFs were very well matched to that obtained by "gold standard" manual blood sampling, but with an increased temporal resolution of up to 1 s. The area under the curve (AUC) ratio between probe- and manually derived IFs was 1.07 ± 0.05 with a coefficient of variation of 0.04. However, image-derived IFs were significantly underestimated compared to the manually sampled IFs, with an AUC ratio of 0.76 ± 0.24 with a coefficient of variation of 0.32. IF derived from the beta microprobe accurately represented the IF as measured by blood sampling, was reproducible, and was more accurate than an image-derived technique. The use of the shunt removed problems of tissue-background activity, and the use of a light-tight probe with minimal gamma sensitivity refined the system. The probe/shunt apparatus can be used in both microprobe and PET studies. [less ▲]

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See detailIN VIVO PET IMAGING OF THE EFFECT OF THE NMDA ANTAGONIST MEMANTINE ON GLUCOSE METABOLISM IN THE RODENT BRAIN
Warnock, Geoffrey ULg; Dedeurwaerdere, Stefanie; Bahri, Mohamed Ali ULg et al

Poster (2010, September)

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See detailTHE EFFECT OF BETA MICROPROBE IMPLANTATION ON THE BLOOD BRAIN BARRIER
Warnock, Geoffrey ULg; Dedeurwaardere, Stefanie; Bahri, Mohamed Ali ULg et al

Poster (2010, September)

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See detailDISPLACEMENT OF 18F-FALLYPRIDE BINDING WITH HALOPERIDOL IN A WITHIN-SUBJECT DESIGN USING A BETA MICROPROBE
Warnock, Geoffrey ULg; Goblet, David ULg; Lemaire, Christian ULg et al

in Journal of Cerebral Blood Flow & Metabolism (2009, October), 29(S1), 352-353

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See detailAccurate measurement of arterial input function during FDG PET using a beta microprobe
Warnock, Geoffrey ULg; Lemaire, Christian ULg; Langlois, Xavier et al

in Journal of Cerebral Blood Flow & Metabolism (2009, October), 29(S1), 339-339

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See detailTIME-DEPENDENT PREFERENTIAL IN VIVO D2 OCCUPANCY BY AMISULPRIDE IN THE MEDIAL STRIATUM – CONTINUOUS MEASUREMENT USING A BETA MICROPROBE SYSTEM
Warnock, Geoffrey ULg; Goblet, David ULg; Lemaire, Christian ULg et al

in Journal of Labelled Compounds & Radiopharmaceuticals (2009, July), 52(S1), 105

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See detailUSE OF A BETA MICROPROBE SYSTEM AS AN AFFORDABLE TRANSLATIONAL TOOL COMPARED TO PET – EXAMPLES USING FDG AND 18F-FALLYPRIDE BINDING
Warnock, Geoffrey ULg; Goblet, David ULg; Lemaire, Christian ULg et al

in Journal of Labelled Compounds & Radiopharmaceuticals (2009, July), 52(S1), 55

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See detailTHE USEFULNESS OF AN ARTERIOVENOUS SHUNT COMBINED WITH A BETA MICROPROBE FOR THE MEASUREMENT OF INPUT FUNCTION IN RATS
Warnock, Geoffrey ULg; Goblet, David ULg; Lemaire, Christian ULg et al

in Journal of Labelled Compounds & Radiopharmaceuticals (2009, July), 52(S1), 106

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See detailIn vivo evidence for ligand-specific receptor activation in the central CRF system, as measured by local cerebral glucose utilization.
Warnock, Geoffrey ULg; Moechars, Dieder; Langlois, Xavier et al

in Peptides (2009), 30(5), 947-54

Corticotropin-releasing factor (CRF) is well known for its role in the hypothalamic-pituitary-adrenocortical (HPA) axis and its involvement in stress and anxiety. CRF acts via two main receptor subtypes ... [more ▼]

Corticotropin-releasing factor (CRF) is well known for its role in the hypothalamic-pituitary-adrenocortical (HPA) axis and its involvement in stress and anxiety. CRF acts via two main receptor subtypes, CRF(1) and CRF(2). Other endogenous CRF-related peptide ligands are the Urocortins 1 and 2 and Stresscopin. While CRF is thought to mediate its anxiogenic-like properties through CRF(1), the role of CRF(2) and its endogenous ligands Urocortin 2 and Stresscopin are less clear, with a suggested role in mediating the delayed effects of stress. Measurement of local cerebral glucose utilization (LCGU) provides an estimate of neuronal activity, and is of potential use as a translational tool in comparison to FDG PET. We hypothesized that comparison of the patterns of metabolic changes induced by CRF-related peptides could provide further information on their role in the brain. The present studies examined the effects of CRF-related peptides on LCGU, and the role of CRF(1) and CRF(2) in the CRF-induced LCGU response. CRF induced increases in LCGU in hypothalamic, thalamic, cerebellar and hippocampal regions, and further studies using antagonists or mutant mice lacking a functional CRF(1) receptor clearly suggested a role for CRF(2) in this effect. Urocortin 1 increased LCGU in a dissected hindbrain region. However, central administration of the CRF(2)-selective agonists Urocortin 2 and Stresscopin failed to affect LCGU, which may suggest ligand-dependent receptor activation within the CRF system. The present data supports a role for CRF(2) in the regulation of neuronal glucose metabolism. [less ▲]

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