Inter-individual variability in resting-state cerebral metabolism in normal aging: Cognitive reserve as a potential mediator

Conference (2011)

Identifying the default-mode component in spatial IC analyses of patients with disorders of consciousness.

in Human Brain Mapping (2011)

Objectives:Recent fMRI studies have shown that it is possible to reliably identify the default-mode network (DMN) in the absence of any task, by resting-state connectivity analyses in healthy volunteers ... [more ▼]

Objectives:Recent fMRI studies have shown that it is possible to reliably identify the default-mode network (DMN) in the absence of any task, by resting-state connectivity analyses in healthy volunteers. We here aimed to identify the DMN in the challenging patient population of disorders of consciousness encountered following coma. Experimental design: A spatial independent component analysis-based methodology permitted DMN assessment, decomposing connectivity in all its different sources either neuronal or artifactual. Three different selection criteria were introduced assessing anticorrelation-corrected connectivity with or without an automatic masking procedure and calculating connectivity scores encompassing both spatial and temporal properties. These three methods were validated on 10 healthy controls and applied to an independent group of 8 healthy controls and 11 severely brain-damaged patients [locked-in syndrome (n = 2), minimally conscious (n = 1), and vegetative state (n = 8)]. Principal observations: All vegetative patients showed fewer connections in the default-mode areas, when compared with controls, contrary to locked-in patients who showed near-normal connectivity. In the minimally conscious-state patient, only the two selection criteria considering both spatial and temporal properties were able to identify an intact right lateralized BOLD connectivity pattern, and metabolic PET data suggested its neuronal origin. Conclusions: When assessing resting-state connectivity in patients with disorders of consciousness, it is important to use a methodology excluding non-neuronal contributions caused by head motion, respiration, and heart rate artifacts encountered in all studied patients. Hum Brain Mapp, 2011. (c) 2011 Wiley-Liss, Inc. [less ▲]

Kinetic modelling of 18F-fallypride binding to dopamine receptors – a comparison between beta microprobe and microPET

Poster (2010, September)

THE EFFECT OF BETA MICROPROBE IMPLANTATION ON THE BLOOD BRAIN BARRIER

Poster (2010, September)

DISPLACEMENT OF 18F-FALLYPRIDE BINDING WITH HALOPERIDOL IN A WITHIN-SUBJECT DESIGN USING A BETA MICROPROBE

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

Comparaison of reference tissue model versus two compartement model with input function for [18F]Fallypride modelling. A combined microPET-Beta microprobe study in rat.

in Journal of Labelled Compounds & Radiopharmaceuticals (2009, July 12), 52(S1), 108

USE OF A BETA MICROPROBE SYSTEM AS AN AFFORDABLE TRANSLATIONAL TOOL COMPARED TO PET – EXAMPLES USING FDG AND 18F-FALLYPRIDE BINDING

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

The CMC-like behaviour of bile salts as probed by photoexcited Rose Bengal

in Colloids and Surfaces A : Physicochemical and Engineering Aspects (2009), 339

The onset of the aggregation process in aqueous bile salt (BS) solutions remains a debated question. This study aimed at investigating this point through the detection of BS monomers and small aggregates ... [more ▼]

The onset of the aggregation process in aqueous bile salt (BS) solutions remains a debated question. This study aimed at investigating this point through the detection of BS monomers and small aggregates using the dye Rose Bengal. Results showed that a few small BS aggregates led to a red shift of the absorption spectrum, while the BS monomer reacted with the photo-induced semi-oxidized dye and decreased its decay rate constant. The dye was dissolved in aqueous solution (10 mmol dm-3 NaOH) of sodium cholate (NaC), deoxycholate (NaDC), chenodoxycholate (NaCDC), dehydrocholate (NaDHC), glycocholate (NaGC) glycodeoxycholate (NaGDC), taurocholate (NaTC), taurodeoxycholate (NaTDC) and the zwitterionic analogue of sodium cholate called CHAPS. BS aggregates were detected at concentrations well below the concentration above which any added bile salt molecules participate in the aggregation process for all trihydroxy bile salts and for CHAPS but not for the dihydroxy bile salts. No aggregation of NaDHC could be observed in the studied concentration range (≤ 10 mmol dm-3). The presence of 150 and 600 mmol dm-3 sodium ions lowered the concentration below which BS are mainly monomers for dihydroxy but not for trihydroxy bile salts. As already proposed by others, the use of the concept of Micellar Dissociation Concentration (MDC) is suggested here instead of the classical Critical Micelle Concentration (CMC). [less ▲]

Quantification of Randomly-methylated-b-cyclodextrin effect on liposome: An ESR study

in Biochemical and Biophysical Research Communications (2009), 390

In the present work, the effect of Randomly-methylated-b-cyclodextrin (Rameb) on the microviscosity of dimyristoyl-L-a phosphatidylcholine (DMPC) bilayer was investigated using the electron spin resonance ... [more ▼]

In the present work, the effect of Randomly-methylated-b-cyclodextrin (Rameb) on the microviscosity of dimyristoyl-L-a phosphatidylcholine (DMPC) bilayer was investigated using the electron spin resonance (ESR) technique. The ability of Rameb to extract membrane cholesterol was demonstrated. For the first time, the percentage of cholesterol extracted by Rameb from cholesterol doped DMPC bilayer was monitored and quantified throughout a wide Rameb concentration range. The effect of cholesterol on the inner part of the membrane was also investigated using 16-doxyl stearic acid spin label (16-DSA). 16-DSA seems to explore two different membrane domains and report their respective microviscosities. ESR experiments also establish that the presence of 30% of cholesterol in DMPC liposomes suppresses the jump in membrane fluidity at lipids phase-transition temperature (23.9°C). [less ▲]

Effect of statin on liposome and cell membranes fluidity. An ESR spin probe study

Poster (2008, May 16)