021: Clopidogrel low response and correlation between the different tests: light transmission aggregometry, VerifyNow-P2Y12 and V ASP

BackgroundClopidogrel low response correlates with poor prognosis after percutaneous coronary intervention (PCI). Many biological tests are currently available to test the clopidogrel response. However, the presence of any correlation between the different tests is today poorly reported.MethodsIn this prospective study, clopidogrel response was assessed in 100 consecutive patients. All patients were tested between 18h and 24h after a600mg clopidogrel loading dose using 3 different tests: light transmission aggregometry with 10μmol ADP (LTA, results expressed as platelet inhibition percentage), VerifyNow-P2Y12 (VN, results expressed as PRU) and vasodilatator stimulated phosphoprotein (VASP, results expressed as IRP). Patients under chronic clopidogrel therapy were excluded.ResultsThe mean platelet inhibition percentage, PRU value and IRP value were 38.5±13% by LTA, 178±89 PRU by VN and 52±21% by VASP. When results were analyzed as continuous variables, there was a good correlation between the different tests: LTA/VN (R2=0,642, p<0,001), LTA/VASP (R2=0,409, p<0,001) and VN/VASP (R2=0,616, p<0,001). However, when results were analyzed as pre-specified cut-off points to define patients as “low or good responders” (according to the literature: 50% for LTA, 235 PRU for VN and 50% IRP for VASP), only 47% of the patients were defined as “good” or “low responders” by the 3 tests. Altogether, 33% of the patients were defined as “low responders” by only 1 test, 20% by 2 tests and only 16% by the 3 tests.ConclusionIf the correlation between the different tests is good when results are analyzed as continuous variables, each individual is rarely (less than 50%) defined as “low or good responder” by all the 3 tests when recognized cut-off values are used. In that way, a sole test might not be sufficient to manage antiplatelet therapy in an individual patient

Impact of initial clinical presentation on clopidogrel low response

SummaryBackgroundLarge interindividual variability exists in clopidogrel response. Clopidogrel low response correlates with poor prognosis after percutaneous coronary intervention. Some authors also suggest intraindividual variability over time.AimTo assess the impact of initial clinical presentation on clopidogrel low response.MethodsIn this prospective study, clopidogrel response was assessed in 100 patients. Fifty patients presenting with acute coronary syndromes (ACS group) were compared with 50 patients with stable coronary artery disease matched 1:1 for age, sex, body mass index and diabetes (stable group). All patients were tested 18–24h after a 600mg loading dose of clopidogrel using the VerifyNow-P2Y12 test (results expressed as platelet reaction units [PRUs]). Patients under chronic clopidogrel therapy or treated with glycoprotein IIb/IIIa inhibitors, bivalirudin or thrombolytics were excluded.ResultsMean age was 61±12 years in each group; 28% of patients in each group were diabetic; mean body mass index was 27.6±5.6kg/m2 in the ACS group and 27.9±5.9kg/m2 in the stable group (p=0.80). Mean PRU values were 197±81 in the ACS group and 159±94 in the stable group (p=0.03). By multivariable analysis, the ACS group was significantly associated with a higher PRU value (p=0.02). There were significantly more clopidogrel low responders (PRU value>230) in the ACS group (38% vs. 18%; p=0.04).ConclusionOur study confirms that initial clinical presentation, especially ACS, is a strong predictor of clopidogrel low response; this suggests that the evolution of coronary artery disease for one patient influences the clopidogrel response over time. These results are in accordance with recent trials showing a benefit for more aggressive antiplatelet therapy in ACS patients

Assessment of Translocator Protein Density, as Marker of Neuroinflammation, in Major Depressive Disorder: A Pilot, Multicenter, Comparative, Controlled, Brain PET Study (INFLADEP Study)

Background: Major depressive disorder (MDD) is a serious public health problem with high lifetime prevalence (4.4–20%) in the general population. The monoamine hypothesis is the most widespread etiological theory of MDD. Also, recent scientific data has emphasized the importance of immuno-inflammatory pathways in the pathophysiology of MDD. The lack of data on the magnitude of brain neuroinflammation in MDD is the main limitation of this inflammatory hypothesis. Our team has previously demonstrated the relevance of [18F] DPA-714 as a neuroinflammation biomarker in humans. We formulated the following hypotheses for the current study: (i) Neuroinflammation in MDD can be measured by [18F] DPA-714; (ii) its levels are associated with clinical severity; (iii) it is accompanied by anatomical and functional alterations within the frontal-subcortical circuits; (iv) it is a marker of treatment resistance.Methods: Depressed patients will be recruited throughout 4 centers (Bordeaux, Montpellier, Tours, and Toulouse) of the French network from 13 expert centers for resistant depression. The patient population will be divided into 3 groups: (i) experimental group—patients with current MDD (n = 20), (ii) remitted depressed group—patients in remission but still being treated (n = 20); and, (iii) control group without any history of MDD (n = 20). The primary objective will be to compare PET data (i.e., distribution pattern of neuroinflammation) between the currently depressed group and the control group. Secondary objectives will be to: (i) compare neuroinflammation across groups (currently depressed group vs. remitted depressed group vs. control group); (ii) correlate neuroinflammation with clinical severity across groups; (iii) correlate neuroinflammation with MRI parameters for structural and functional integrity across groups; (iv) correlate neuroinflammation and peripheral markers of inflammation across groups.Discussion: This study will assess the effects of antidepressants on neuroinflammation as well as its role in the treatment response. It will contribute to clarify the putative relationships between neuroinflammation quantified by brain neuroimaging techniques and peripheral markers of inflammation. Lastly, it is expected to open innovative and promising therapeutic perspectives based on anti-inflammatory strategies for the management of treatment-resistant forms of MDD commonly seen in clinical practice.Clinical trial registration (reference: NCT03314155): https://www.clinicaltrials.gov/ct2/show/NCT03314155?term=neuroinflammation&amp;cond=depression&amp;cntry=FR&amp;rank=

Spectroscopie Raman et microfluidique (application à la diffusion Raman exaltée de surface)

Ce mémoire porte sur la mise au point de plateforme microfluidique couplée à la microscopie Raman confocale, utilisée dans des conditions d excitation de la diffusion Raman (diffusion Raman exaltée de surface), dans le but d obtenir une détection de très haute sensibilité d espèces moléculaires sous écoulement dans des canaux de dimensions micrométriques. Ce travail a pour ambition de démontrer la faisabilité d un couplage microscopie Raman/microfluidique en vue de la caractérisation in-situ et locale, des espèces et des réactions mises en jeu dans les fluides en écoulement dans les microcanaux. Nous avons utilisé un microcanal de géométrie T, fabriqué par lithographie douce, dans lequel sont injectées, à vitesse constante, des nanoparticules métalliques d or ou d argent dans une des deux branches du canal et une solution de pyridine ou de péfloxacine dans l autre branche. La laminarité et la stationnarité du processus nous ont permis de cartographier la zone de mélange et de mettre en évidence l exaltation du signal de diffusion Raman de la pyridine et de la péfloxacine, obtenue grâce aux nanoparticules métalliques, dans cette zone d interdiffusion. L enregistrement successif de la bande d absorption des nanoparticules d argent (bande plasmon) et du signal de diffusion Raman de la péfloxacine, en écoulement dans un microcanal, nous a permis d établir un lien entre la morphologie des nanostructures métalliques, et plus précisément l état d agrégation des nanoparticules d argent, et l exaltation du signal Raman de la péfloxacine observé. Nous avons alors modifié la géométrie du canal afin d y introduire une solution d électrolyte (NaCl et NaNO3) et de modifier localement la charge de surface des colloïdes d argent en écoulement. Nous avons ainsi confirmé que la modification de l état d agrégation des nanoparticules d argent, induite par l ajout contrôlé de solutions d électrolytes, permet d amplifier le signal SERS de la péfloxacine et d optimiser la détection en microfluidique. Enfin, nous avons développé une seconde approche qui consistait à mettre en place une structuration métallisée des parois d un microcanal. Nous avons ainsi démontré que la fonctionnalisation chimique de surface via un organosilane (APTES) permettait de tapisser le canal avec des nanoparticules d argent et d amplifier le signal Raman des espèces en écoulement dans ce même microcanal.This thesis focuses on the development of a microfluidic platform coupled with confocal Raman microscopy, used in excitation conditions of Raman scattering (Surface enhanced Raman scattering, SERS) in order to gain in the detection sensitivity of molecular species flowing in channels of micrometer dimensions. This work aims to demonstrate the feasibility of coupling Raman microscopy / microfluidics for the in situ and local characterization of species and reactions taking place in the fluid flowing in microchannels. We used a T-shaped microchannel, made by soft lithography, in which gold or silver nanoparticles injected at constant speed, in one of the two branches of the channel and a solution of pyridine or pefloxacin in the other one. The laminar flow and the stationarity of the process allowed us to map the mixing zone and highlight the enhancement of the Raman signal of pyridine and pefloxacin, due to the metallic nanoparticles, in the interdiffusion zone. The recording of the both absorption band of the silver nanoparticles (plasmon band) and the Raman signal of pefloxacin, flowing in microchannel, allowed us to establish a link between the shape of the metallic nanostructure, and more precisely the silver nanoparticle aggregation state, and the enhancement of the Raman signal of pefloxacin observed. We then changed the channel geometry to introduce an electrolyte solution (NaCl and NaNO3) and locally modify the surface charge of the colloids. We have put in evidence that the change of the silver nanoparticle aggregation state, induced by the controlled addition of electrolyte solutions, could amplify the SERS signal of pefloxacin and thus optimizing the detection in microfluidics. At last, we established second a approach that consists in the metallic structuring of microchannel walls. This has shown that the surface chemical functionalization through organosilanes (APTES) allowed the pasting of the channel with silver nanoparticles, thus amplifying the Raman signal of the species flowing within the same microchannel.BORDEAUX1-Bib.electronique (335229901) / SudocSudocFranceF

New Universal Figure of Merit for Embedded Si Piezoresistive Pressure Sensors

—In this article, we are presenting a new classification methodology for high resolution membrane based MEMS piezoresistive pressure sensors embedded in Internet of Things (IoT) nodes or in body-implanted devices. This is based on a new figure of merit (FoM) that includes the four key parameters as the power consumption, the area, the noise and the sensitivity of the transducer. The proposed classification allows to directly evaluate, based on power consumption and area requirements, the ultimate limit of detection that can be reached by a proposed technology. The derivation of the proposed FoM is validated based on wide survey and comparisons of literature results. It shows that, until now, wet etching technics for membrane release still allow for reaching higher performances than reactive ion etching

A short and efficient synthesis of (R,R)-2-methylcyclopropanecarboxylic acid

We report herein a short and efficient synthesis of (RR)-2methyleyclopropanecarboxylic acid via a Horner-Wadsworth-Emmons reaction involving commercially available (S)-propylene oxide and triethylphosphonoacetate (TEPA). The TEPA/ base/propylene oxide stoichiometry was found critical to achieve high yields. We therefore studied the TEPA anion formation and stability using in situ IR spectroscopy. The reaction yield is strongly influenced by the counterion and solvent, whereas high diastereoselectivities are always obtained. Under the best experimental conditions (HexLi/MeTHF/150 degrees C), crude (RR)2-methylcyclopropanecarboxylic acid is obtained in 85-90% yield with > 98% trans selectivity

Enhancing Partial Discharge Detection by Tuning Residual Stresses in Ultrathin CMOS-compatible Multilayer Membranes for Resonant Frequency Control

Partial Discharges (PD) are destructive events occurring in high-voltage equipment. [1,2] - Electrical discharge that occurs inside an insulating layer but does not cause full short-circuit - Is localised around defects in insulation material - Linked to 85% of assets failures as material deteriorates due to such discharges - Emits wide variety of signals among which a sound wave that is referred to as Acoustic Emission (AE) AE detection can be done using an ultrasound microphone that needs to be sensitive to the 70 kHz to 170 kHz range