Author
Olivier F. Bertrand
Other affiliations: Paris Diderot University, French Institute of Health and Medical Research, University of Lyon ...read more
Bio: Olivier F. Bertrand is an academic researcher from Laval University. The author has contributed to research in topics: Percutaneous coronary intervention & Conventional PCI. The author has an hindex of 81, co-authored 495 publications receiving 33555 citations. Previous affiliations of Olivier F. Bertrand include Paris Diderot University & French Institute of Health and Medical Research.
Papers published on a yearly basis
Papers
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TL;DR: Description of mapping methods using spherical splines, both to interpolate scalp potentials (SPs) and to approximate scalp current densities (SCDs) with greater accuracy in areas with few electrodes.
2,343 citations
TL;DR: This article will focus on the literature on gamma oscillatory activities in humans and will describe the different types of gamma responses and how to analyze them, as well as convergence evidence that suggests that one particular type of gamma activity (induced gamma activity) is observed during the construction of an object representation.
2,031 citations
TL;DR: This work tested the stimulus specificity of high-frequency oscillations in humans using three types of visual stimuli: two coherent stimuli (a Kanizsa and a real triangle) and a noncoherent stimulus (“no-triangle stimulus”).
Abstract: Considerable interest has been raised by non-phase-locked episodes of synchronization in the gamma-band (30-60 Hz). One of their putative roles in the visual modality is feature-binding. We tested the stimulus specificity of high-frequency oscillations in humans using three types of visual stimuli: two coherent stimuli (a Kanizsa and a real triangle) and a noncoherent stimulus ("no-triangle stimulus"). The task of the subject was to count the occurrences of a curved illusory triangle. A time-frequency analysis of single-trial EEG data recorded from eight human subjects was performed to characterize phase-locked as well as non-phase-locked high-frequency activities. We found in early phase-locked 40 Hz component, maximal at electrodes Cz-C4, which does not vary with stimulation type. We describe a second 40 Hz component, appearing around 280 msec, that is not phase-locked to stimulus onset. This component is stronger in response to a coherent triangle, whether real or illusory: it could reflect, therefore, a mechanism of feature binding based on high-frequency synchronization. Because both the illusory and the real triangle are more target-like, it could also correspond to an oscillatory mechanism for testing the match between stimulus and target. At the same latencies, the low-frequency evoked response components phase-locked to stimulus onset behave differently, suggesting that low- and high-frequency activities have different functional roles.
1,460 citations
TL;DR: Among patients with a recent myocardial infarction, colchicine at a dose of 0.5 mg daily led to a significantly lower risk of ischemic cardiovascular events than placebo.
Abstract: Background Experimental and clinical evidence supports the role of inflammation in atherosclerosis and its complications. Colchicine is an orally administered, potent antiinflammatory medi...
1,426 citations
TL;DR: Although waist circumference is a better marker of abdominal fat accumulation than the body mass index, an elevated waistline alone is not sufficient to diagnose visceral obesity and it is proposed that an elevated fasting triglyceride concentration could represent a simple clinical marker of excess visceral/ectopic fat.
Abstract: There is currently substantial confusion between the conceptual definition of the metabolic syndrome and the clinical screening parameters and cut-off values proposed by various organizations (NCEP-ATP III, IDF, WHO, etc) to identify individuals with the metabolic syndrome. Although it is clear that in vivo insulin resistance is a key abnormality associated with an atherogenic, prothrombotic, and inflammatory profile which has been named by some the "metabolic syndrome" or by others "syndrome X" or "insulin resistance syndrome", it is more and more recognized that the most prevalent form of this constellation of metabolic abnormalities linked to insulin resistance is found in patients with abdominal obesity, especially with an excess of intra-abdominal or visceral adipose tissue. We have previously proposed that visceral obesity may represent a clinical intermediate phenotype reflecting the relative inability of subcutaneous adipose tissue to act as a protective metabolic sink for the clearance and storage of the extra energy derived from dietary triglycerides, leading to ectopic fat deposition in visceral adipose depots, skeletal muscle, liver, heart, etc. Thus, visceral obesity may partly be a marker of a dysmetabolic state and partly a cause of the metabolic syndrome. Although waist circumference is a better marker of abdominal fat accumulation than the body mass index, an elevated waistline alone is not sufficient to diagnose visceral obesity and we have proposed that an elevated fasting triglyceride concentration could represent, when waist circumference is increased, a simple clinical marker of excess visceral/ectopic fat. Finally, a clinical diagnosis of visceral obesity, insulin resistance, or of the metabolic syndrome is not sufficient to assess global risk of cardiovascular disease. To achieve this goal, physicians should first pay attention to the classical risk factors while also considering the additional risk resulting from the presence of abdominal obesity and the metabolic syndrome, such global risk being defined as cardiometabolic risk. (Arterioscler Thromb Vasc Biol 2008;28:1039-1049)
1,398 citations
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TL;DR: EELAB as mentioned in this paper is a toolbox and graphic user interface for processing collections of single-trial and/or averaged EEG data of any number of channels, including EEG data, channel and event information importing, data visualization (scrolling, scalp map and dipole model plotting, plus multi-trial ERP-image plots), preprocessing (including artifact rejection, filtering, epoch selection, and averaging), Independent Component Analysis (ICA) and time/frequency decomposition including channel and component cross-coherence supported by bootstrap statistical methods based on data resampling.
17,362 citations
9,362 citations
TL;DR: The current guidelines for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation are based on the findings of the ESC Task Force on 12 March 2015.
Abstract: ESC Guidelines for the management of acute coronary syndromes in patients presenting without persistent ST-segment elevation : The Task Force for the management of acute coronary syndromes (ACS) in patients presenting without persistent ST-segment elevation of the European Society of Cardiology (ESC).
6,866 citations
TL;DR: 2017 ESC Guidelines for the management of acute myocardial infarction in patients presenting with ST-segment elevation are published.
Abstract: 2017 ESC Guidelines for the management of acute myocardial infarction in patients presenting with ST-segment elevation The Task Force for the management of acute myocardial infarction in patients presenting with ST-segment elevation of the European Society of Cardiology (ESC)
6,599 citations
TL;DR: These findings suggest that the BOLD contrast mechanism reflects the input and intracortical processing of a given area rather than its spiking output, and that LFPs yield a better estimate of BOLD responses than the multi-unit responses.
Abstract: Functional magnetic resonance imaging (fMRI) is widely used to study the operational organization of the human brain, but the exact relationship between the measured fMRI signal and the underlying neural activity is unclear. Here we present simultaneous intracortical recordings of neural signals and fMRI responses. We compared local field potentials (LFPs), single- and multi-unit spiking activity with highly spatio-temporally resolved blood-oxygen-level-dependent (BOLD) fMRI responses from the visual cortex of monkeys. The largest magnitude changes were observed in LFPs, which at recording sites characterized by transient responses were the only signal that significantly correlated with the haemodynamic response. Linear systems analysis on a trialby-trial basis showed that the impulse response of the neurovascular system is both animal- and site-specific, and that LFPs yield a better estimate of BOLD responses than the multi-unit responses. These findings suggest that the BOLD contrast mechanism reflects the input and intracortical processing of a given area rather than its spiking output.
6,140 citations