Matrix approach of Full-Field OCT for volumetric imaging of an opaque human cornea

Optical microscopy offers the possibility to image biological tissue with a diffraction limited resolution (~µm). However, the heterogeneity of biological tissues can strongly affect light propagation at large depths by distorting the initial wavefront. Large and short range fluctuations of the refractive index can induce aberration and multiple scattering, respectively. Inspired by a recent work [1], we have developed a matrix approach to Full-Field Optical Coherence Tomography (FF-OCT) to push back the fundamental limit of aberrations and multiple scattering. Here, we report on the application of this approach to the imaging of the human cornea and the quantitative measurement of the corneal transparency. Please click Additional Files below to see the full abstract

Multi-Spectral Reflection Matrix for Ultra-Fast 3D Label-Free Microscopy

Label-free microscopy exploits light scattering to obtain a three-dimensional image of biological tissues. However, light propagation is affected by aberrations and multiple scattering, which drastically degrade the image quality and limit the penetration depth. Multi-conjugate adaptive optics and time-gated matrix approaches have been developed to compensate for aberrations but the associated frame rate is extremely limited for 3D imaging. Here we develop a multi-spectral matrix approach to solve these fundamental problems. Based on an interferometric measurement of a polychromatic reflection matrix, the focusing process can be optimized in post-processing at any voxel by addressing independently each frequency component of the wave-field. A proof-of-concept experiment demonstrates the three-dimensional image of an opaque human cornea over a 0.1 mm^3-field-of-view at a 290 nm-resolution and a 1 Hz-frame rate. This work paves the way towards a fully-digital microscope allowing real-time, in-vivo, quantitative and deep inspection of tissues.Comment: 27 pages, 4 figure

Hepatitis C virus and atherosclerosis: A legacy after virologic cure?

publisher: Elsevier articletitle: Hepatitis C virus and atherosclerosis: A legacy after virologic cure? journaltitle: Clinics and Research in Hepatology and Gastroenterology articlelink: http://dx.doi.org/10.1016/j.clinre.2016.09.008 content_type: article copyright: © 2016 Elsevier Masson SAS. All rights reserved

Dissection aortique anevrismale chez un adulte infecte par le VIH-1 dans le cadre d'un syndrome de reconstitution immune avec tuberculose

We here report the case of a 35-year old man with HIV-1 but with no previous medical-surgical history hospitalized in Abidjan, Cote d'Ivoire, due to fever, cough, dyspnea, chest pain and unfolding of the aortic arch observed on chest x-ray a week after having started antiretroviral therapy (ART). CT angiography of the thoracic aorta showed overall, extended aortic ectasia with mural thrombus. Transesophageal echocardiography objectified type A ascending aortic dissection (Stanford classification). The diagnosis of tuberculosis was confirmed based on Mycobacterium tuberculosis culture isolation. Eight years after, the patient was still alive without surgical treatment and complained of intermittent chest pain. Blood pressure was stable with moderate renal failure. We here report a rare case of aortic aneurism dissection in an adult patient with tuberculosis infected with HIV-1 during immune reconstitution inflammatory syndrome

Long-term effects of evolocumab in participants with HIV and dyslipidemia: results from the open-label extension period

Objectives: People with HIV (PWH) are at an increased risk of atherosclerotic cardiovascular disease. Suboptimal responses to statin therapy in PWH may result from antiretroviral therapies (ARTs). This open-label extension study aimed to evaluate the long-term safety and efficacy of evolocumab up to 52\u200aweeks in PWH. Design: This final analysis of a multinational, placebo-controlled, double-blind, randomized phase 3 trial evaluated the effect of monthly subcutaneous evolocumab 420\u200amg on low-density lipoprotein cholesterol (LDL-C) during the open-label period (OLP) following 24\u200aweeks of double-blind period in PWH with hypercholesterolemia/mixed dyslipidemia. All participants enrolled had elevated LDL-C or nonhigh-density lipoprotein cholesterol (non-HDL-C) and were on stable maximally tolerated statin and stable ART. Methods: Efficacy was assessed by percentage change from baseline in LDL-C, triglycerides, and atherogenic lipoproteins. Treatment-emergent adverse events (TEAEs) were examined. Results: Of the 467 participants randomized in the double-blind period, 451 (96.6%) received at least one dose of evolocumab during the OLP (mean age of 56.4\u200ayears, 82.5% male, mean duration with HIV of 17.4\u200ayears). By the end of the 52-week OLP, the overall mean (SD) percentage change in LDL-C from baseline was -57.8% (22.8%). Evolocumab also reduced triglycerides, atherogenic lipid parameters (non-HDL-C, apolipoprotein B, total cholesterol, very-low-density lipoprotein cholesterol, and lipoprotein[a]), and increased HDL-C. TEAEs were similar between placebo and evolocumab during the OLP. Conclusion: Long-term administration of evolocumab lowered LDL-C and non-HDL-C, allowing more PWH to achieve recommended lipid goals with no serious adverse events. Trail registration: NCT02833844. Video abstract: http://links.lww.com/QAD/C441

New Insights in the Contribution of Voltage-Gated Nav Channels to Rat Aorta Contraction

BACKGROUND: Despite increasing evidence for the presence of voltage-gated Na(+) channels (Na(v)) isoforms and measurements of Na(v) channel currents with the patch-clamp technique in arterial myocytes, no information is available to date as to whether or not Na(v) channels play a functional role in arteries. The aim of the present work was to look for a physiological role of Na(v) channels in the control of rat aortic contraction. METHODOLOGY/PRINCIPAL FINDINGS: Na(v) channels were detected in the aortic media by Western blot analysis and double immunofluorescence labeling for Na(v) channels and smooth muscle alpha-actin using specific antibodies. In parallel, using real time RT-PCR, we identified three Na(v) transcripts: Na(v)1.2, Na(v)1.3, and Na(v)1.5. Only the Na(v)1.2 isoform was found in the intact media and in freshly isolated myocytes excluding contamination by other cell types. Using the specific Na(v) channel agonist veratridine and antagonist tetrodotoxin (TTX), we unmasked a contribution of these channels in the response to the depolarizing agent KCl on rat aortic isometric tension recorded from endothelium-denuded aortic rings. Experimental conditions excluded a contribution of Na(v) channels from the perivascular sympathetic nerve terminals. Addition of low concentrations of KCl (2-10 mM), which induced moderate membrane depolarization (e.g., from -55.9+/-1.4 mV to -45.9+/-1.2 mV at 10 mmol/L as measured with microelectrodes), triggered a contraction potentiated by veratridine (100 microM) and blocked by TTX (1 microM). KB-R7943, an inhibitor of the reverse mode of the Na(+)/Ca(2+) exchanger, mimicked the effect of TTX and had no additive effect in presence of TTX. CONCLUSIONS/SIGNIFICANCE: These results define a new role for Na(v) channels in arterial physiology, and suggest that the TTX-sensitive Na(v)1.2 isoform, together with the Na(+)/Ca(2+) exchanger, contributes to the contractile response of aortic myocytes at physiological range of membrane depolarization

La crise du modèle autoritaire

Boccara Paul. La crise du modèle autoritaire. In: Recherches Internationales, n°36, 1990. p. 73

Practical Considerations for the Use of Subcutaneous Treatment in the Management of Dyslipidaemia

International audienceSuboptimal drug adherence represents a major challenge to effective primary and secondary prevention of cardiovascular disease. While adherence is influenced by multiple considerations, polypharmacy and dosing frequency appear to be rate-limiting factors in patient satisfaction and subsequent adherence. The cardiovascular and metabolic therapeutic areas have recently benefited from a number of advances in drug therapy, in particular protease proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors and incretin-based therapies, respectively. These drugs are administered subcutaneously and offer efficacious treatment options with reduced dosing frequency. Whilst patients with diabetes and diabetologists are well initiated to injectable therapies, the cardiovascular therapeutic arena has traditionally been dominated by oral agents. It is therefore important to examine the practical aspects of treating patients with these new lipid-lowering agents, to ensure they are optimally deployed in everyday clinical practice