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Featured researches published by Antoine Poncet.


Annals of Surgical Oncology | 2013

Risk factors for survival after lung metastasectomy in colorectal cancer patients: a systematic review and meta-analysis.

Michel Gonzalez; Antoine Poncet; Christophe Combescure; John Robert; Hans Beat Ris; Pascal Gervaz

BackgroundResection of lung metastases (LM) from colorectal cancer (CRC) is increasingly performed with a curative intent. It is currently not possible to identify those CRC patients who may benefit the most from this surgical strategy. The aim of this study was to perform a systematic review of risk factors for survival after lung metastasectomy for CRC.MethodsWe performed a meta-analysis of series published between 2000 and 2011, which focused on surgical management of LM from CRC and included more than 40 patients each. Pooled hazard ratios (HR) were calculated by using random effects model for parameters considered as potential prognostic factors.ResultsTwenty-five studies including a total of 2925 patients were considered in this analysis. Four parameters were associated with poor survival: (1) a short disease-free interval between primary tumor resection and development of LM (HR 1.59, 95 % confidence interval [CI] 1.27–1.98); (2) multiple LM (HR 2.04, 95 % CI 1.72–2.41); (3) positive hilar and/or mediastinal lymph nodes (HR 1.65, 95 % CI 1.35–2.02); and (4) elevated prethoracotomy carcinoembryonic antigen (HR 1.91, 95 % CI 1.57–2.32). By comparison, a history of resected liver metastases (HR 1.22, 95 % CI 0.91–1.64) did not achieve statistical significance.ConclusionsClinical variables associated with prolonged survival after surgery for LM in CRC patients include prolonged disease-free interval between primary tumor and metastatic spread, normal prethoracotomy carcinoembryonic antigen, absence of thoracic node involvement, and a single pulmonary lesion.


JAMA | 2014

Association between early administration of high-dose erythropoietin in preterm infants and brain MRI abnormality at term-equivalent age.

Russia Ha-Vinh Leuchter; Laura Gui; Antoine Poncet; Cornelia Hagmann; Gregory Anton Lodygensky; Ernst Martin; Brigitte Koller; Alexandra Darque; Hans Ulrich Bucher; Petra Susan Hüppi

IMPORTANCE Premature infants are at risk of developing encephalopathy of prematurity, which is associated with long-term neurodevelopmental delay. Erythropoietin was shown to be neuroprotective in experimental and retrospective clinical studies. OBJECTIVE To determine if there is an association between early high-dose recombinant human erythropoietin treatment in preterm infants and biomarkers of encephalopathy of prematurity on magnetic resonance imaging (MRI) at term-equivalent age. DESIGN, SETTING, AND PARTICIPANTS A total of 495 infants were included in a randomized, double-blind, placebo-controlled study conducted in Switzerland between 2005 and 2012. In a nonrandomized subset of 165 infants (n=77 erythropoietin; n=88 placebo), brain abnormalities were evaluated on MRI acquired at term-equivalent age. INTERVENTIONS Participants were randomly assigned to receive recombinant human erythropoietin (3000 IU/kg; n=256) or placebo (n=239) intravenously before 3 hours, at 12 to 18 hours, and at 36 to 42 hours after birth. MAIN OUTCOMES AND MEASURES The primary outcome of the trial, neurodevelopment at 24 months, has not yet been assessed. The secondary outcome, white matter disease of the preterm infant, was semiquantitatively assessed from MRI at term-equivalent age based on an established scoring method. The resulting white matter injury and gray matter injury scores were categorized as normal or abnormal according to thresholds established in the literature by correlation with neurodevelopmental outcome. RESULTS At term-equivalent age, compared with untreated controls, fewer infants treated with recombinant human erythropoietin had abnormal scores for white matter injury (22% [17/77] vs 36% [32/88]; adjusted risk ratio [RR], 0.58; 95% CI, 0.35-0.96), white matter signal intensity (3% [2/77] vs 11% [10/88]; adjusted RR, 0.20; 95% CI, 0.05-0.90), periventricular white matter loss (18% [14/77] vs 33% [29/88]; adjusted RR, 0.53; 95% CI, 0.30-0.92), and gray matter injury (7% [5/77] vs 19% [17/88]; adjusted RR, 0.34; 95% CI, 0.13-0.89). CONCLUSIONS AND RELEVANCE In an analysis of secondary outcomes of a randomized clinical trial of preterm infants, high-dose erythropoietin treatment within 42 hours after birth was associated with a reduced risk of brain injury on MRI. These findings require assessment in a randomized trial designed primarily to assess this outcome as well as investigation of the association with neurodevelopmental outcomes. TRIAL REGISTRATION clinicaltrials.gov Identifier: NCT00413946.


European Journal of Nuclear Medicine and Molecular Imaging | 2014

Detection and quantification of focal uptake in head and neck tumours: 18 F-FDG PET/MR versus PET/CT

Arthur Varoquaux; Olivier Rager; Antoine Poncet; Bénédicte M. A. Delattre; Osman Ratib; Christoph Becker; Pavel Dulguerov; Nicolas Dulguerov; Habib Zaidi; Minerva Becker

PurposeOur objectives were to assess the quality of PET images and coregistered anatomic images obtained with PET/MR, to evaluate the detection of focal uptake and SUV, and to compare these findings with those of PET/CT in patients with head and neck tumours.MethodsThe study group comprised 32 consecutive patients with malignant head and neck tumours who underwent whole-body 18F-FDG PET/MR and PET/CT. PET images were reconstructed using the attenuation correction sequence for PET/MR and CT for PET/CT. Two experienced observers evaluated the anonymized data. They evaluated image and fusion quality, lesion conspicuity, anatomic location, number and size of categorized (benign versus assumed malignant) lesions with focal uptake. Region of interest (ROI) analysis was performed to determine SUVs of lesions and organs for both modalities. Statistical analysis considered data clustering due to multiple lesions per patient.ResultsPET/MR coregistration and image fusion was feasible in all patients. The analysis included 66 malignant lesions (tumours, metastatic lymph nodes and distant metastases), 136 benign lesions and 470 organ ROIs. There was no statistically significant difference between PET/MR and PET/CT regarding rating scores for image quality, fusion quality, lesion conspicuity or anatomic location, number of detected lesions and number of patients with and without malignant lesions. A high correlation was observed for SUVmean and SUVmax measured on PET/MR and PET/CT for malignant lesions, benign lesions and organs (ρ = 0.787 to 0.877, p < 0.001). SUVmean and SUVmax measured on PET/MR were significantly lower than on PET/CT for malignant tumours, metastatic neck nodes, benign lesions, bone marrow, and liver (p < 0.05). The main factor affecting the difference between SUVs in malignant lesions was tumour size (p < 0.01).ConclusionIn patients with head and neck tumours, PET/MR showed equivalent performance to PET/CT in terms of qualitative results. Comparison of SUVs revealed an excellent correlation for measurements on both modalities, but underestimation of SUVs measured on PET/MR as compared to PET/CT.


Circulation | 2012

Antiplatelet Drug Response Status Does Not Predict Recurrent Ischemic Events in Stable Cardiovascular Patients Results of the Antiplatelet Drug Resistances and Ischemic Events Study

Jean-Luc Reny; P. Berdagué; Antoine Poncet; Isabelle Barazer; Séverine Nolli; P. Fabbro-Peray; Jean-François Schved; Henri Bounameaux; François Mach; Philippe de Moerloose; Pierre Fontana

Background— The biological response to antiplatelet drugs has repeatedly been shown to predict the recurrence of major adverse cardiovascular events (MACEs). However, most studies involved coronary artery disease patients with recent vessel injury shortly after the initiation of antiplatelet therapy. Data on stable cardiovascular patients are scarce, and the added predictive value of specific assays (the vasodilator phosphoprotein assay for the clopidogrel response and serum thromboxane B2 for the aspirin response) and aggregation-based assays relative to common predictors has rarely been addressed. Methods and Results— Stable cardiovascular outpatients participating in the Antiplatelet Drug Resistances and Ischemic Events (ADRIE) study (n=771) were tested twice, at 2 separate visits, with specific and aggregation-based assays. Follow-up lasted 3 years, and <1% of patients were lost to follow-up. MACEs were adjudicated by an independent committee. Multivariate survival analyses included relevant variables identified in univariate analysis and platelet function test results. The C-index was used to express the prognostic value of various multivariate models. MACEs, the primary end point, occurred in 16% of patients. Hypertension, smoking, older age, and elevated low-density lipoprotein cholesterol were predictive of MACE recurrence, with a C-index of 0.63 (P<0.001). Neither the specific nor the aggregation-based assays added significant predictive value for the primary end point. Conclusions— Biological antiplatelet drug responsiveness, measured with specific or aggregation-based assays, has no incremental predictive value over common cardiovascular risk factors for MACE recurrence in stable cardiovascular outpatients. These results do not support platelet function testing for MACE risk evaluation in stable cardiovascular patients. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00501423.


Circulation | 2012

Antiplatelet Drug Response Status Does Not Predict Recurrent Ischemic Events in Stable Cardiovascular Patients: Results of the ADRIE Study

Jean-Luc Reny; P. Berdagué; Antoine Poncet; Isabelle Barazer; Séverine Nolli; P. Fabbro-Peray; Jean-François Schved; Henri Bounameaux; François Mach; Philippe de Moerloose; Pierre Fontana

Background— The biological response to antiplatelet drugs has repeatedly been shown to predict the recurrence of major adverse cardiovascular events (MACEs). However, most studies involved coronary artery disease patients with recent vessel injury shortly after the initiation of antiplatelet therapy. Data on stable cardiovascular patients are scarce, and the added predictive value of specific assays (the vasodilator phosphoprotein assay for the clopidogrel response and serum thromboxane B2 for the aspirin response) and aggregation-based assays relative to common predictors has rarely been addressed. Methods and Results— Stable cardiovascular outpatients participating in the Antiplatelet Drug Resistances and Ischemic Events (ADRIE) study (n=771) were tested twice, at 2 separate visits, with specific and aggregation-based assays. Follow-up lasted 3 years, and <1% of patients were lost to follow-up. MACEs were adjudicated by an independent committee. Multivariate survival analyses included relevant variables identified in univariate analysis and platelet function test results. The C-index was used to express the prognostic value of various multivariate models. MACEs, the primary end point, occurred in 16% of patients. Hypertension, smoking, older age, and elevated low-density lipoprotein cholesterol were predictive of MACE recurrence, with a C-index of 0.63 (P<0.001). Neither the specific nor the aggregation-based assays added significant predictive value for the primary end point. Conclusions— Biological antiplatelet drug responsiveness, measured with specific or aggregation-based assays, has no incremental predictive value over common cardiovascular risk factors for MACE recurrence in stable cardiovascular outpatients. These results do not support platelet function testing for MACE risk evaluation in stable cardiovascular patients. Clinical Trial Registration— URL: http://www.clinicaltrials.gov. Unique identifier: NCT00501423.


Critical Care | 2014

Hospital mortality of adults admitted to Intensive Care Units in hospitals with and without Intermediate Care Units: a multicentre European cohort study

Maurizia Capuzzo; Carlo Alberto Volta; Tania Tassinati; Rui Moreno; Andreas Valentin; Bertrand Guidet; Gaetano Iapichino; Claude Martin; Thomas V. Perneger; Christophe Combescure; Antoine Poncet; Andrew Rhodes

IntroductionThe aim of the study was to assess whether adults admitted to hospitals with both Intensive Care Units (ICU) and Intermediate Care Units (IMCU) have lower in-hospital mortality than those admitted to ICUs without an IMCU.MethodsAn observational multinational cohort study performed on patients admitted to participating ICUs during a four-week period. IMCU was defined as any physically and administratively independent unit open 24 hours a day, seven days a week providing a level of care lower than an ICU but higher than a ward. Characteristics of hospitals, ICUs and patients admitted to study ICUs were recorded. The main outcome was all-cause in-hospital mortality until hospital discharge (censored at 90 days).ResultsOne hundred and sixty-seven ICUs from 17 European countries enrolled 5,834 patients. Overall, 1,113 (19.1%) patients died in the ICU and 1,397 died in hospital, with a total of 1,397 (23.9%) deaths. The illness severity was higher for patients in ICUs with an IMCU (median Simplified Acute Physiology Score (SAPS) II: 37) than for patients in ICUs without an IMCU (median SAPS II: 29, P <0.001). After adjustment for patient characteristics at admission such as illness severity, and ICU and hospital characteristics, the odds ratio of mortality was 0.63 (95% CI 0.45 to 0.88, P = 0.007) in favour of the presence of IMCU. The protective effect of the IMCU was absent in patients who were admitted for basic observation, for example, after surgery (odds ratio 1.15, 95% CI 0.65 to 2.03, P = 0.630) but was strong in patients admitted to an ICU for other reasons (odds ratio 0.54, 95% CI 0.37 to 0.80, P = 0.002).ConclusionsThe presence of an IMCU in the hospital is associated with significantly reduced adjusted hospital mortality for adults admitted to the ICU. This effect is relevant for the patients requiring full intensive treatment.Trial registrationClinicaltrials.gov NCT01422070. Registered 19 August 2011.


Journal of Hepatology | 2014

Accurate computed tomography-based portal pressure assessment in patients with hepatocellular carcinoma

Pouya Iranmanesh; Oscar Vazquez; Sylvain Terraz; Pietro Majno; Laurent Spahr; Antoine Poncet; Philippe Morel; Gilles Mentha; Christian Toso

BACKGROUND & AIMS Liver resection is generally restricted to patients without clinically significant portal hypertension (Hepatic Venous Pressure Gradient - HVPG - ⩽10mmHg) and several teams perform transjugular HVPG measurements as part of the pre-operative work-up. The present study investigates whether a non-invasive Computed Tomography (CT)-based assessment could be as accurate as the invasive transjugular measurement. METHODS A cohort of patients with hepatocellular carcinoma (HCC) treated by resection (n=36) or transplantation (n=39) was selected (mean age: 61±9.2years, male/female ratio: 4/1). Pre-operative CTs were read by two independent investigators, and potential CT-based HVPG predictors were compared to the transjugular HVPG measurements. A validation was conducted on another cohort of 70 non-surgical patients. RESULTS The invasive HVPG values were significantly correlated to liver/spleen volume ratio, spleen volume, platelet count, and peri-hepatic ascites (p<0.001), which all showed high inter-observer agreements (intra-class correlation coefficients ⩾0.927, Kappa ⩾0.945). The presence of a HVPG >10mmHg was best predicted by the liver/spleen volume ratio (AUC: 0.883 [0.805-0.960]) and the peri-hepatic ascites (p<0.001). These two variables were combined into an accurate model for predicting HVPG >10mmHg (AUC: 0.911 [0.847-0.975]), with sensitivity, specificity, and positive and negative predictive values of 92%, 79%, 91%, and 81%. The model was also accurate in the validation cohort with an AUC of 0.820 [0.719-0.921]. The computed formula was: CONCLUSIONS The proposed CT-based model showed a high accuracy in the prediction of HVPG and, if further confirmed by prospective validation, could replace the invasive transjugular assessment in patients not requiring a biopsy of the non-tumoral liver.


Platelets | 2015

Impact of non-inhibited platelet supplementation on platelet reactivity in patients treated with prasugrel or ticagrelor for an acute coronary syndrome: An ex vivo study.

Fanny Bonhomme; Robert F. Bonvini; Jean-Luc Reny; Antoine Poncet; Pierre Fontana

Abstract Managing bleeding in patients receiving P2Y12 inhibitors is challenging. Few data are available regarding the efficacy of platelet transfusion in patients treated with prasugrel or ticagrelor. The aim of this study was to evaluate the minimal amount of platelet supplementation (in terms of ratio of non-inhibited platelets to inhibited platelets) necessary to restore platelet reactivity in platelet-rich plasma (PRP) of patients treated with aspirin and a prasugrel or ticagrelor loading dose for an acute coronary syndrome. PRP samples from patients were mixed ex vivo with increasing proportions of pooled PRP from healthy volunteers. Platelet reactivity was challenged with adenosine diphosphate (ADP), arachidonic acid, collagen or thrombin receptor activating peptide using light transmission aggregometry. The primary endpoint was the proportion of patient samples recovering an ADP-induced maximal aggregation (ADP-Aggmax) value above 40%. In patients treated with prasugrel (n = 32), ADP-Aggmax increased progressively with supplements of pooled PRP, with an average increase of 7.9% (95% CI [7.1; 8.8], p < 0.001) per each 20% increase in the ratio of non-inhibited platelets to inhibited platelets. A ratio of 60% was associated with 90% of patients reaching the primary endpoint. In patients treated with ticagrelor (n = 15), ADP-Aggmax did not significantly increase with any level of supplements. In conclusions, ex vivo addition of non-inhibited platelets significantly improved ADP-Aggmax in patients treated with prasugrel with a dose-dependent effect. There was no evidence of such a reversal in patients treated with ticagrelor. These results suggest that platelet transfusion may be more effective in blunting bleeding in patients treated with prasugrel, than those treated with ticagrelor.


Pain | 2015

GABAergic modulation in central sensitization in humans: a randomized placebo-controlled pharmacokinetic-pharmacodynamic study comparing clobazam with clonazepam in healthy volunteers

Marie Besson; Alain Matthey; Youssef Daali; Antoine Poncet; Pascal Henri Vuilleumier; Michele Curatolo; Hanns Ulrich Zeilhofer; Jules Alexandre Desmeules

Abstract Positive allosteric modulators of GABAA receptors (GAMs) acting at specific subtypes of GABAA receptors effectively restore compromised spinal pain control in rodents. Studies addressing a similar antihyperalgesic effect in humans are sparse and are hampered by sedative effects of nonselective GAMs available for use in humans. We present results from a randomized controlled double-blind crossover study in 25 healthy volunteers, which addressed potential antihyperalgesic actions of clobazam (CBZ) and clonazepam (CLN) at mildly sedating equianticonvulsive doses. Clobazam was chosen because of its relatively low sedative properties and CLN because of its use in neuropathic pain. Tolterodine (TLT) was used as an active placebo. The primary outcome parameter was a change in the area of cutaneous UVB irradiation–induced secondary hyperalgesia (ASH), which was monitored for 8 hours after drug application. Sedative effects were assessed in parallel to antihyperalgesia. Compared with TLT, recovery from hyperalgesia was significantly faster in the CBZ and CLN groups (P = 0.009). At the time point of maximum effect, the rate of recovery from hyperalgesia was accelerated by CBZ and CLN, relative to placebo by 15.7% (95% confidence interval [CI] 0.8-30.5), P = 0.040, and 28.6% (95% CI 4.5-52.6), P = 0.022, respectively. Active compounds induced stronger sedation than placebo, but these differences disappeared 8 hours after drug application. We demonstrate here that GAMs effectively reduce central sensitization in healthy volunteers. These results provide proof-of-principle evidence supporting efficacy of GAMs as antihyperalgesic agents in humans and should stimulate further research on compounds with improved subtype specificity.


Current Medicinal Chemistry | 2013

Embryonic Stem Cell-Based Screen for Small Molecules: Cluster Analysis Reveals Four Response Patterns in Developing Neural Cells

Ilse Kern; Ruodan Xu; Stéphanie Julien; David M. Suter; Olivier Preynat-Seauve; Mathurin Baquié; Antoine Poncet; Christophe Combescure; Luc Stoppini; Christoph van Thriel; Karl-Heinz Krause

Neural differentiation of embryonic stem cells (ESC) is considered a promising model to perform in vitro testing for neuroactive and neurotoxic compounds. We studied the potential of a dual reporter murine ESC line to identify bioactive and/or toxic compounds. This line expressed firefly luciferase under the control of the neural cell-specific tubulin alpha promoter (TUBA1A), and renilla luciferase under the control of the ubiquitous translation elongation factor 1-alpha-1 (EEF1A1) promoter. During neural differentiation, TUBA1A activity increased, while EEF1A1 activity decreased. We first validated our test system using the known neurotoxin methyl mercury. This compound altered expression of both reporter genes, with ESC-derived neural precursors being affected at markedly lower concentrations than undifferentiated ESCs. Analysis of a library of 1040 bioactive compounds picked up 127 compounds with altered EEF1A1 and/or TUBA1A promoter activity, which were classified in 4 clusters. Cluster 1 (low EEF1A1 and TUBA1A) was the largest cluster, containing many cytostatic drugs, as well as known neurodevelopmental toxicants, psychotropic drugs and endocrine disruptors. Cluster 2 (high EEF1A1, stable TUBA1A) was limited to three sulfonamides. Cluster 3 (high EEF1A1 and TUBA1A) was small, but markedly enriched in neuroactive and neurotoxic compounds. Cluster 4 (stable EEF1A1, high TUBA1A) was heterogeneous, containing endocrine disruptors, neurotoxic and cytostatic drugs. The dual reporter gene assay described here might be a useful addition to in vitro drug testing panels. Our two-dimensional testing strategy provides information on complex response patterns, which could not be achieved by a single marker approach.

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