A fluid mechanical view on abdominal aortic aneurysms

International audienceAbdominal aortic aneurysms are a dilatation of the aorta, localized preferentially above the bifurcation of the iliac arteries, which increases in time. Understanding their localization and growth rate remain two open questions that can have either a biological or a physical origin. In order to identify the respective role of biological and physical processes, we address in this article these questions of the localization and growth using a simplified physical experiment in which water (blood) is pumped periodically (amplitude a, pulsation ) in an elastic membrane (aorta) (length L, cross-section A0 and elastic wave speed c0) and study the deformation of this membrane while decharging in a rigid tube (iliac artery; hydraulic loss K). We first show that this pulsed flow either leads to a homogenous deformation or inhomogenous deformation depending on the value of the non-dimensional parameter c0 2/(aL2K). These different regimes can be related to the aneurysm locations. In the second part, we study the growth of aneurysms and show that they only develop above a critical flow rate which scales as A0c0/K. © 2010 Cambridge University Press

Pseudoxanthoma elasticum and obstetric epidural analgesia: Report of a case

peer reviewedPseudoxanthoma elasticum is a rare inherited disorder of the elastic tissue characterised by multisystem manifestations. Skin, eyes, gastro-intestinal system and cardiovascular system are the major affected systems. We describe the anaesthetic management of a parturient affected by this disease

Interferon β-1a in relapsing multiple sclerosis: four-year extension of the European IFNβ-1a Dose-C omparison Study

Background: Multiple sclerosis (MS) is a chronic disease requiring long-term monitoring of treatment. Objective: To assess the four-year clinical efficacy of intramuscular (IM) IFNb-1a in patients with relapsing MS from the European IFNb-1a Dose-C omparison Study. Methods: Patients who completed 36 months of treatment (Part 1) of the European IFNb-1a Dose-C omparison Study were given the option to continue double-blind treatment with IFNb-1a 30 mcg or 60 mcg IM once weekly (Part 2). Analyses of 48-month data were performed on sustained disability progression, relapses, and neutralizing antibody (NA b) formation. Results: O f 608/802 subjects who completed 36 months of treatment, 493 subjects continued treatment and 446 completed 48 months of treatment and follow-up. IFNb-1a 30 mcg and 60 mcg IM once weekly were equally effective for up to 48 months. There were no significant differences between doses over 48 months on any of the clinical endpoints, including rate of disability progression, cumulative percentage of patients who progressed (48 and 43, respectively), and annual relapse rates; relapses tended to decrease over 48 months. The incidence of patients who were positive for NAbs at any time during the study was low in both treatment groups. Conclusion: C ompared with 60-mcg IM IFNb-1a once weekly, a dose of 30 mcg IM IFNb-1a once weekly maintains the same clinical efficacy over four years

Patient expression of emotions and neurologist responses in first multiple sclerosis consultations

Background: Anxiety and depression are common in people with multiple sclerosis (MS), but data on emotional communication during MS consultations are lacking. We assessed patient expressions of emotion and neurologist responses during first-ever MS consultations using the Verona Coding Definitions of Emotional Sequences (VR-CoDES). Methods: We applied VR-CoDES to recordings/transcripts of 88 outpatient consultations (10 neurologists, four MS Italian centers). Before consultation, patients completed the Hospital Anxiety and Depression Scale (HADS). Multilevel sequential analysis was performed on the number of cues/concerns expressed by patients, and the proportion of reduce space responses by neurologists. Results: Patients expressed 492 cues and 45 concerns (median 4 cues and 1 concern per consultation). The commonest cues were verbal hints of hidden worries (cue type b, 41%) and references to stressful life events (type d, 26%). Variables independently associated with number of cues/concerns were: anxiety (HADS-Anxiety score >8) (incidence risk ratio, IRR 1.08, 95% CI 1.06-1.09; p<0.001); patient age (IRR 0.98, 95% CI 0.98-0.99; p<0.001); neurologist age (IRR 0.94, 95% CI 0.92-0.96; p=0.03); and second opinion consultation (IRR 0.72, 95% CI 0.60-0.86; p=0.007). Neurologists reacted to patient emotions by reducing space (changing subject, taking no notice, giving medical advice) for 58% of cues and 76% of concerns. Anxiety was the only variable significantly associated with 'reduce space' responses (odds ratio 2.17, 95% CI 1.32-3.57; p=0.003). Conclusions: Patient emotional expressions varied widely, but VR-CoDES cues b and d were expressed most often. Patient anxiety was directly associated with emotional expressions; older age of patients and neurologists, and second opinion consultations were inversely associated with patient emotional expression. In over 50% of instances, neurologists responded to these expressions by reducing space, more so in anxious patients. These findings suggest that neurologists need to improve their skills in dealing with patient emotions

Short- and mid-term effects on performance, health and qualitative behavioural assessment of Romane lambs in different milk feeding conditions

The common practice of artificially rearing lambs from prolific meat breeds of sheep constitutes a welfare issue due to increased mortality rates and negative health issues. In this multidisciplinary study, we investigated the possible short- and mid-term advantages of artificially feeding fresh ewe's milk instead of commercial milk replacer on lambs' growth, health and welfare. Romane lambs were either separated from their mothers on D3 and fed with Lacaune ewes' milk (LAC, n?=?13) or milk replacer (REP, n?=?15), or they were reared by their mothers (MOT, n =?15). On D45, they were weaned, gathered in single-sex groups until the end of the study on D150. Lamb performance and biomarkers of overall health were assessed by measuring: growth, dirtiness of the perianal area, enteric pathogens in the faeces, total antioxidant status and redox status assessed by plasma reduced glutathione/oxidised glutathione ratio, and immune response after vaccination against chlamydiosis. As an exploratory approach, blood cell transcriptomic profiles were also investigated. Last, qualitative behaviour assessment (QBA) was performed as an integrated welfare criterion. Lacaune ewes' milk and REP never differed in their average daily gain but grew less than MOT lambs in the early suckling period and just after weaning. No effect was detected afterwards. On D30, LAC and REP lambs had lower total antioxidant and higher redox status than MOT lambs but did not differ among themselves. Lacaune ewes' milk and MOT had a cleaner perianal area than REP lambs on D21, while faecal pathogen infection did not vary between the treatment groups. After vaccination, LAC also had a stronger immune response on D90 compared to REP lambs. Transcriptome analysis performed on D150 showed differential gene expression, mainly in relation to inflammatory, immune and cell cycle response, between male lambs of the LAC group and those of the MOT and REP groups. Based on QBA, LAC lambs never differed from MOT lambs in their general activity and varied from REP only on D21; REP lambs were always more agitated than MOT lambs. In conclusion, artificial milk feeding impaired early growth rate, health and emotional state mainly during the milk feeding period and at weaning. Feeding artificially reared lambs with fresh ewe's milk partly mitigated some of the negative effects induced by milk replacer but without achieving the full benefit of being reared by the mother

MD1003 (high-dose biotin) for the treatment of progressive multiple sclerosis: A randomised, double-blind, placebo-controlled study.

BACKGROUND: Treatment with MD1003 (high-dose biotin) showed promising results in progressive multiple sclerosis (MS) in a pilot open-label study. OBJECTIVE: To confirm the efficacy and safety of MD1003 in progressive MS in a double-blind, placebo-controlled study. METHODS: Patients (n = 154) with a baseline Expanded Disability Status Scale (EDSS) score of 4.5-7 and evidence of disease worsening within the previous 2 years were randomised to 12-month MD1003 (100 mg biotin) or placebo thrice daily, followed by 12-month MD1003 for all patients. The primary endpoint was the proportion of patients with disability reversal at month 9, confirmed at month 12, defined as an EDSS decrease of ⩾1 point (⩾0.5 for EDSS 6-7) or a ⩾20% decrease in timed 25-foot walk time compared with the best baseline among screening or randomisation visits. RESULTS: A total of 13 (12.6%) MD1003-treated patients achieved the primary endpoint versus none of the placebo-treated patients (p = 0.005). MD1003 treatment also reduced EDSS progression and improved clinical impression of change compared with placebo. Efficacy was maintained over follow-up, and the safety profile of MD1003 was similar to that of placebo. CONCLUSION: MD1003 achieves sustained reversal of MS-related disability in a subset of patients with progressive MS and is well tolerated.journal article2016 Nov2016 09 01importe

L'épuration domestique de l'eau par filtration

L'étude de trois épurateurs d'eau domestiques est présentée. Après avoir exposé les principes de fonctionnement des appareils et la composition des médias filtrants utilisés, l'étude expérimentale consiste à déterminer : - l'influence de la filtration épuratrice sur les caractères physico-chimiques de l'eau, - l'efficacité vis à vis du mauvais goût dû au chlore, - l'efficacité vis à vis des microorganismes, - le colmatage des milieux filtrants et leur durée d'utilisation. Aucun des trois appareils étudiés n'est satisfaisant et l'eau dite «purifiée» par leurs fabricants est une eau dégradée par rapport à l'eau du robinet

Etude physico-chimique et bio-géochimique du colmatage de puits captants par des manganobactéries du genre leptothrix. Conception d'un procédé de décolmatage et de maintenance des ouvrages

L'alimentation en eau de villes en bordure de Loire (France) s'effectue le plus souvent par pompage dans la nappe alluviale du fleuve par l'intermédiaire de puits captants établis dans des îles fluviales. Ce mode d'alimentation est affecté par le colmatage des crépines et des drains des ouvrages de captage par des processus chimiobactériens ayant pour origine le développement de colonies de manganobactéries du genre Leptothrix et/ou Sphaerotilus. Depuis ces dernières décennies, la modification du climat ligérien, la réalisation de barrages sur la Loire, et la sollicitation sans cesse croissante des ouvrages captants du fait de l'urbanisation ont intensifié ces processus avec, pour conséquence, une baisse importante de productivité des champs captants conduisant à des situations critiques. Nos recherches ont porté en premier lieu sur la physico-chimie et l'hydrochimie de l'aquifère dans les conditions d'exploitation, ce qui a permis de mettre en évidence notamment l'influence des conditions de pompage sur les équilibres redox. En second lieu, l'étude de la géomicrobiologie de l'aquifère nous a permis, d'une part, d'identifier Leptothrix discophora comme responsable des colmatages et, d'autre part, d'élaborer en laboratoire un procédé de décolmatage et de maintenance des puits fondé sur des injections de gaz chlorhydrique, de vapeur d'eau sous pression (120°C) et de dioxyde de soufre au niveau des zones colmatées. La faisabilité de ce procédé sulfitochlorhydrique a été ensuite démontrée sur une maquette de laboratoire avant de l'appliquer sur le terrain