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The Montfort Postnatal Care-at-Home (MPCH) Program is an innovative, integrated physician, nurse and midwifery model of care that offers an early hospital discharge option to families. The MPCH Program provides care and support to families throughout their transition from hospital to home. The program has the potential to improve families' experiences and maternal-newborn health outcomes, and provides a safety net to families 24/7 during the first seven days postpartum at home. This model transforms how postnatal care is delivered, and has the potential to improve the flow of the birthing unit and the unit capacity and reduce acute care hospital costs.

Cet article présente les résultats d’une analyse de contenu de nature lexicométrique, réalisée sur un corpus de textes composé de rapports du Groupe de travail sur l’enseignement de l’histoire (1996), du Groupe de travail sur la réforme du curriculum (1997) et du Comité d’experts chargé d’étudier la question du renforcement de l’histoire au secondaire (2014). Ces rapports ont en commun d’avoir proposé des recommandations curriculaires en matière d’enseignement de l’histoire. Notre objectif a consisté à identifier des orientations convergentes et divergentes à travers ces trois rapports. Les résultats indiquent, d’une part, la présence d’un discours commun, en faveur d’une réforme curriculaire. D’autre part, ces résultats révèlent de fortes spécificités, notamment au regard du rapport du Comité d’experts chargé d’étudier la question du renforcement de l’histoire au secondaire (2014) militant pour une approche nationaliste., This article presents the results of a lexicometrical content analysis carried out on a corpus of texts drawn from the Work Group on History Teaching (1996), the Work Group on Curriculum Reform (1997) and the Committee of Experts responsible for studying the question of strengthening history in secondary school (2014). These reports recommended changes in history teaching for the last twenty years, underpinning the writing of Quebec’s history curriculums. This analysis aims to identify convergent and divergent orientations across the data to assess their consistency. On one hand, the results demonstrate the presence of a core discourse about the importance of reform in education. On the other hand, these results show strong discourse specificity across the data, particularly acute for the Committee of Experts responsible for studying the question of strengthening history in secondary school (2014) striving for a nationalist approach., Este artículo presenta los resultados de un análisis de contenido de naturaleza lexicométrica, realizado sobre un corpus de textos compuesto de informes del Grupo de trabajo sobre la enseñanza de la historia (1996), del Grupo de trabajo sobre la reforma del currículo (1997) y del Comité de expertos encargado de estudiar la cuestión del refuerzo de la enseñanza de la historia en secundaria (2014). Estos informes tienen en común el hecho de que proponen recomendaciones curriculares en materia de la enseñanza de la historia. Nuestro objetivo consistió en identificar las orientaciones convergentes y divergentes a través de estos tres informes. Los resultados indican, por un lado, la presencia de un discurso común, en favor de una reforma curricular. Por otro lado, estos resultados revelan fuertes especificidades, en particular en el informe del Comité de expertos encargado de estudiar la cuestión del refuerzo de la enseñanza de la historia en secundaria (2014), militando por un enfoque de refuerzo de los elementos propios a la provincia.

Cet article propose une analyse conceptuelle des écrits scientifiques anglophones sur la pensée historique sous l’angle de la problématisation des apprentissages. Une telle démarche est nécessaire dans le contexte actuel. D’une part, les prescrits didactiques incitent les enseignants à problématiser les apprentissages en classe d’histoire. D’autre part, les modèles de pensée historique véhiculés par ces écrits sont sollicités dans l’espace francophone par de nombreux didacticiens. L’objectif de cette analyse consiste à interroger ces modèles sous l’angle de la problématisation, pour rendre compte des situations-problèmes qu’ils commandent. Trois types de situation-problème sont identifiés. Un premier consiste à problématiser en fonction des concepts disciplinaires de la pensée historique. Un deuxième cible le processus de résolution par modelage et mise en oeuvre d’euristiques. Un troisième repose sur l’induction de structures sous-tendant les pratiques sociales. Des éléments de convergence et de divergence entre ces types de situation-problème sont discutés au terme de cette analyse conceptuelle., This article offers a conceptual analysis of English-language scientific writings on historical thought from the angle of the problematization of learning. Such an approach is necessary in today’s context. On one hand, educational prescriptions encourage teachers to problematize learning in history classes. On the other hand, the models of historical thought conveyed in these writings are solicited by many educators in the French- speaking world. The purpose of this analysis is to investigate these models from the angle of problematization, to understand the situation-problems they govern. Three types of situation-problems are identified. One is to problematize according to the disciplinary concepts of historical thought. A second targets the process of resolution through modeling and the implementation of heuristics. A third is based on the introduction of structures underlying social practices. Elements of convergence and divergence between these types of situation-problems are discussed at the end of this conceptual analysis., Este artículo presenta un análisis conceptual de los escritos científicos anglófonos sobre el pensamiento histórico desde la perspectiva de la problematización de los aprendizajes. Tal planteamiento es necesario en el contexto actual. Por una parte, las prescripciones didácticas incitan a los maestros a problematizar los aprendizajes en clase de historia. Por otra parte, los modelos del pensamiento histórico vehiculados por dichos escritos son requeridos en el espacio francófono por numerosos didactas. El objetivo de este análisis es interrogar esos modelos desde la perspectiva de la problematización, para comprender las situaciones-problemas que conllevan. Tres tipos de situación problema fueron identificados. El primero consiste en problematizar en función de los conceptos disciplinarios del pensamiento histórico. El segundo centra el proceso de resolución por modelado y ejecución de huerísticos. El tercero se basa en la inducción de estructuras que sustentan las prácticas sociales. Al final de este análisis conceptual se discuten los elementos de convergencia y divergencia entre esos tipos de situación-problema.

Both personality and motivational characteristics can be considered to estimate individuals’ potential for adjustment and development. That said, these characteristics are rarely studied in conjunction. In this study, we examine how personality and motivational characteristics relate one to the other and influence how students approach learning. More precisely, we analyzed the additive and interactive effects of two intimately related traits (extraversion and emotional stability) from the Big Five model of personality on five motivational dimensions reflecting academic expectations (sense of competence) and values (interest, utility, and mastery and performance goal orientations). Data was collected from a sample of 303 students in tenth and eleventh grade (108 boys and 195 girls; Mage = 16.275 years, SD = 1.149) in a French-Canadian public high school in the greater Quebec City area. Primary analyses included both bivariate correlation and hierarchical regression analyses. Correlations indicated that emotionally stable students were more interested in learning. Hierarchical regression showed that emotionally stable students were more likely to exhibit a performance goal orientation, especially when they were extroverted. These analyses also revealed that emotionally stable students were more interested in learning, especially when they had a strong sense of competence. Results are discussed in light of the limited but relevant existing literature.

Moho Nord is a deep-water exploration and development project launched off the Congolese coast in March 2013. This huge investment is the largest oil & gas project ever undertaken in the Republic of the Congo and with a capacity of 140,000 barrels of oil per day. This project, operated by TOTAL (with CHEVRON and SNPC as partners) taps deposits located in water depths of 650 to 1,200 meters and connects 28 subsea wells to two Floating Production Units (FPU), with an additional 17 wells developed from a Tension Leg Platform (TLP). The project involves numerous operations as drilling, testing and completing the wells. However, these deep-water operations are extremely cost-intensive and environmentally challenging, thereby representing a high-risk/high-reward scenario. Due to the intrinsic complexities involved in deep-water operations, it demands meticulous operational planning and dictates the use of technology/practices, which maximizes quality information while minimizing rig time; with a minimal impact on the environment. This paper discusses an ongoing success story on Subsea Riser Inspection at Moho Nord, showcasing the unique challenges encountered in the operations. Also, the lessons learnt from the post-operational studies of this campaign can be utilized to optimize the future riser inspection operations globally; to achieve a more engineered approach towards operations. On Moho Nord TLP, a drilling/production riser is a conduit that provides a temporary/permanent extension of a subsea wellhead to the surface drilling/production facility (where the surface BOP is located); but is extremely critical to preserve the operational integrity of the well. Therefore, robust design followed by routine inspection and monitoring of riser integrity is crucial for the campaign’s success. The literature of oil & gas industry doesn’t report many such cases of successful subsea inspection campaigns, thereby making this a unique campaign for the operator. The campaign involved evaluating the internal and external surfaces of 18.75 inch (0.85 inch thick) Drilling & 10.75 inch (0.45 inch thick) Production risers, for which ultrasonic measurement was utilized. This technique allows scanning the pipe with high radial (up to 1.2 inch) and vertical (0.6 inch) resolutions and the measurement resolutions of 0.002 inch are achieved for both the accurate internal radius and thickness. Minimal operational footprint, well known technology, faster logging speed & quick processing in a short turnaround time (TAT) are some of the additional benefits which have resulted in choosing the ultrasonic measurement as the optimal choice for this campaign. So far 16 ultrasonic logs have been recorded in the first 8 wells across the production risers, 7 ultrasonic logs across the drilling riser and a time-lapse analysis is being carried out to continuously monitor the internal and external condition of the drilling & production risers thereby ensuring overall operational integrity of the well. This ongoing project has shown exceptional synergy between various stakeholders in the project, which has resulted in a total of > 200 hrs. of operating time with >99% operational efficiency. This paper documents the lessons learnt, leading to best practices which could be adapted anywhere globally for planning of subsea riser inspection campaigns. Also, the strengths and limitations of the ultrasonic measurement for riser inspection is clearly highlighted.

Background: Atrial fibrillation (AF) is common after acute myocardial infarction (AMI) and associated with in-hospital and long-term mortality. However, the pathophysiology of AF in AMI is poorly understood. Heart rate variability (HRV), measured by Holter-ECG, reflects cardiovascular response to the autonomic nervous system and altered (reduced or enhanced) HRV may have a major role in the onset of AF in AMI patients. Objective: We investigated the relationship between autonomic dysregulation and new-onset AF during AMI. Methods: As part of the RICO survey, all consecutive patients hospitalized for AMI at Dijon (France) university hospital between June 2001 and November 2014 were analyzed by Holter-ECG &lt, 24 h following admission. HRV was measured using temporal and spectral analysis. Results: Among the 2040 included patients, 168 (8.2%) developed AF during AMI. Compared to the sinus-rhythm (SR) group, AF patients were older, had more frequent hypertension and lower left ventricular ejection fraction LVEF. On the Holter parameters, AF patients had higher pNN50 values (11% vs. 4%, p &lt, 0.001) and median LH/HF ratio, a reflection of sympathovagal balance, was significantly lower in the AF group (0.88 vs 2.75 p &lt, 0.001). The optimal LF/HF cut-off for AF prediction was 1.735. In multivariate analyses, low LF/HF &lt, 1.735 (OR(95%CI) = 3.377 (2.047&ndash, 5.572))was strongly associated with AF, ahead of age (OR(95%CI) = 1.04(1.01&ndash, 1.06)), mean sinus-rhythm rate (OR(95%CI) = 1.03(1.02&ndash, 1.05)) and log NT-proBNP (OR(95%CI) = 1.38(1.01&ndash, 1.90). Conclusion: Our study strongly suggests that new-onset AF in AMI mainly occurs in a dysregulated autonomic nervous system, as suggested by low LF/HF, and higher PNN50 and RMSSD values.

Cet article poursuit dans le sillage d’une analyse conceptuelle réalisée antérieurement. Dans cette analyse, nous interrogions le rapport des programmes d’histoire publiés au Québec depuis la réforme curriculaire entamée au début des années 1980 à l’apprentissage de la pensée historique. Cet article a pour objectif d’éclaircir ces divergences par une analyse lexicométrique du programme d’Histoire et éducation à la citoyenneté. Pour ce faire, une analyse factorielle des correspondances a été réalisée de manière à mettre au jour des traits structuraux spécifiques. Ces derniers rejoignent certaines propriétés associées à l'apprentissage de la pensée historique, et quelques-unes apparaissent confuses., This paper continues along a previous conceptual analysis, questioning Quebec’s history programs published since the curricular reform of 1980’s in regard to learning historical thinking. It is acknowledged that this learning is woven in these history programs, associated with analysis abilities and active citizenship participation. However, a comparative analysis of the History of Québec and Canada program with the History and Citizenship Education program presently implemented revealed divergences about learning historical thinking. The objective of this paper is to shed some light on these differences by doing a lexicometrical analysis of the latter program. A factorial analysis of correspondence permitted a description of the structural features of this program. Some of these features can be attributed to historical thinking learning, and a few seem to be confuse., Este artículo continúa un análisis conceptual realizado anteriormente, en el que se cuestionaba la relación entre los programas de historia publicados en Quebec a partir de la reforma curricular iniciada al comienzo de los años 80 y el aprendizaje del pensamiento histórico. En este artículo nos planteamos aclarar estas divergencias a través de un análisis lexicométrico del programa de Historia y educación a la ciudadanía. Para ello se realizó un análisis factorial de correspondencias con el objetivo de actualizar algunos rasgos estructurales específicos. Éstos son similares a algunas propiedades asociadas al aprendizaje del pensamiento histórico, aunque algunos parezcan confusos.

Cet article porte sur l’analyse d’une interprétation des deux plus récents programmes d’histoire nationale publiés au Québec, leur attribuant l’apprentissage de la pensée : une lecture critique s’appuyant sur les six critères définis par Martineau (1997), premier chercheur à avoir formulé cette interprétation, permettra de révéler une divergence dans trois d’entre eux : 1) le caractère signifiant de l’apprentissage ; 2) la métacognition ; et 3) la fréquence de l’exercice. Cette divergence va justifier la pertinence, d’une part, d’une analyse plus approfondie de ces programmes, et, d’autre part, d’une révision de ces critères en fonction de nouveaux fondements théoriques., This article addresses the association of historical thinking in the two recently published Quebec programs : the new national history program and the previous one. A critical reading is based on the six criteria presented by Martineau (1997) – the researcher first describing this association – to illustrate a lack of convergence between both of these documents. Three of those criteria suggest different meaning concerning the signification of the learning process, metacognition process and frequency. This lack of convergence suggests two problems, closely related, both of interpretation of those history programs and of conceptualization of historical thinking. These problems highlight the relevance of an analysis of these programs and a revision of the theoretical premises on which historical thinking is built., Este artículo trata del análisis de una interpretación de los dos programas más recientes de historia nacional publicados en Quebec con relación al aprendizaje del pensamiento : una lectura crítica basada en los seis criterios definidos por Martineau (1997), investigador que primero formuló esta interpretación, permitirá revelar una discrepancia en tres de ellos : 1) el carácter significante del aprendizaje, 2) la metacognición y 3) la frecuencia del ejercicio. Esta discrepancia va a justificar la pertinencia, por una parte, de un análisis más amplio de estos programas, y por otra parte, de una revisión de estos criterios acorde a nuevos fundamentos teóricos.

Energy efficiency is a first-order design goal for nearly all classes of processors, but it is particularly important in mobile and embedded systems. Data caches in such systems account for a large portion of the processor's energy usage, and thus techniques to improve the energy efficiency of the cache hierarchy are likely to have high impact. Our prior work reduced data cache energy via a tagless access buffer (TAB) that sits at the top of the cache hierarchy. Strided memory references are redirected from the level-one data cache (L1D) to the smaller, more energy-efficient TAB. These references need not access the data translation lookaside buffer (DTLB), and they can avoid unnecessary transfers from lower levels of the memory hierarchy. The original TAB implementation requires changing the immediate field of load and store instructions, necessitating substantial ISA modifications. Here we present a new TAB design that requires minimal instruction set changes, gives software more explicit control over TAB resource management, and remains compatible with legacy (non-TAB) code. With a line size of 32 bytes, a four-line TAB can eliminate 31% of L1D accesses, on average. Together, the new TAB, L1D, and DTLB use 22% less energy than a TAB-less hierarchy, and the TAB system decreases execution time by 1.7%.

Conventional set-associative data cache accesses waste energy since tag and data arrays of several ways are simultaneously accessed to sustain pipeline speed. Different access techniques to avoid activating all cache ways have been previously proposed in an effort to reduce energy usage. However, a problem that many of these access techniques have in common is that they need to access different cache memory portions in a sequential manner, which is difficult to support with standard synchronous SRAM memory.We propose the speculative halt-tag access (SHA) approach, which accesses low-order tag bits, i.e., the halt tag, in the address generation stage instead of the SRAM access stage to eliminate accesses to cache ways that cannot possibly contain the data. The key feature of our SHA approach is that it determines which tag and data arrays need to be accessed early enough for conventional SRAMs to be used. We evaluate the SHA approach using a 65-nm processor implementation running MiBench benchmarks and find that it on average reduces data access energy by 25.6%.

The aim of this study was to evaluate the involvement of mitochondria in the mechanism of the anti-arrhythmic lidocaine. Rats were fed with a diet containing either n-6 polyunsaturated fatty acids (PUFAs, SSO group) or an equimolecular mixture of n-3 and n-6 PUFAs (FO group) for 8 weeks. The hearts were perfused according to the working mode using a medium with or without lidocaine 5 μM. They were then subjected to local ischemia (20 min) and reperfusion (30 min). Dietary n-3 PUFAs triggered the expected decrease in the n-6/n-3 PUFA ratio of cardiac phospholipids. Reperfusing the ischemic area favored the incidence of severe arrhythmias. Lidocaine treatment abolished almost completely reperfusion arrhythmias in the FO group, but did not display anti-arrhythmic properties in the SSO group. As it was indicated by measurements of the mitochondrial function, lidocaine seemed to favor mitochondrial calcium retention in the FO group, which might prevent cytosolic calcium spikes and reperfusion arrhythmias. In the SSO group, the resistance to lidocaine was associated with an aggravation of cellular damages. The mitochondrial calcium retention capacities were saturated, and lidocaine was unable to increase them, making the drug inefficient in preventing reperfusion arrhythmias.

Asymmetric dimethylarginine (ADMA) is an endogenous modulator of endothelial function and oxidative stress, and increased levels of this molecule have been reported in some metabolic disorders and cardiovascular diseases. The aim of this work was to analyze the time course of dimethylarginine compounds and oxidative stress levels and the relationship between these and cardiovascular function in fructose-hypertensive rats.90 male Sprague-Dawley rats were randomized into 2 groups, fed for 3 months with standard (C) chow supplemented or not with fructose (F, 60%). After sacrifice at different weeks (W), the aorta and plasma were harvested to assess the vascular and biochemical parameters. Our work showed that the plasma levels of ADMA in the fructose-fed rats increased after 2 weeks of the diet (1.6 ± 0.3 μM vs. 1.2 ± 0.3 μM, p0.05) with no changes in plasma levels of either SDMA or L-arginine and after an increase in glycemia. Levels of vascular oxidative stress, estimated in aortic segments using an oxidative fluorescence technique, were higher in the F group (W2: 1.14 ± 0.2% vs. 0.33 ± 0.02%, p0.01). An increase in expression levels of nitrotyrosine (3-fold) and iNOS (2-fold) were noted in the fructose-fed rats. After 1 month, this was associated with a significant increase in NAD(P)H oxidase activity. Concerning vascular function, a 15% decrease in maximal endothelium-dependent relaxation was found in the aorta of the F group. Our work showed that the presence of exogenous L-MMA, an inhibitor of NO synthase, was associated with a significant reduction in endothelium-dependent relaxation in isolated aorta rings of the C group; this effect was not observed in the vessels of fructose-fed rats.Our findings suggest that the elevated levels of ADMA observed could in part be secondary to the early development of oxidative stress associated with the development of hypertension.

BACKGROUND: There is evidence that ischemia lasting more than 4 hours affects cardiac allograft survival. Ischemia and reperfusion are associated with additional deleterious effects. Protective effects of preconditioning are already being used but protocols based on postconditioning have not been evaluated. We tested the impact of postconditioning on hearts maintained in the cold for a long period of total global ischemia and we compared the results with those obtained with pyruvate, a cardioprotective molecule. METHODS: Isolated working rat hearts were subjected to a global total ischemia (4 h/4 degrees C), followed by 45 min of reperfusion. Postconditioning consisted of brief total global ischemia applied three times during the onset of reperfusion (ischemia: 30 sec, reperfusion: 30 sec). Superoxide anion production and collagen content were evaluated on cryosections. RESULTS: Our results showed that postconditioning led to improvements in cardiac functions that were comparable to those conferred by pyruvate. Postconditioning reduced myocardial damage, gave better functional recovery, and better preserved the collagen content. It reduced the duration of arrhythmias at the onset of reperfusion. In the postconditioning group, this improvement was associated with a reduction in superoxide production. CONCLUSIONS: In conclusion, our study showed that postconditioning induced good cardioprotective effects in a long cold (4 hr/4 degrees C) ischemia protocol and led to lower O2 production in part mediated by the reduction in NAPDH oxidase activity. It is interesting to note that, in our experimental conditions, the beneficial effects of postconditioning were comparable to those produced by pyruvate.

The aim of our study was to evaluate the acute effect of epirubicin (EPI), an anthracycline anticancer drug, on the evolution of cardiac functional parameters and production of reactive oxygen/nitrogen species (RONS). Isolated perfused rat hearts were subjected to 70 minutes of EPI (10.3 microM) infusion and to 5 minutes of isoproterenol (ISO, 0.1 microM) at the end of the protocol. Coronary flow (CF), left ventricular developed pressure (LVDP), and lactate dehydrogenase (LDH) release in the coronary effluents were evaluated throughout the protocol. RONS were detected in the coronary effluents by electron spin resonance spectroscopy with a spin probe, 1-hydroxy-3-carboxy-pyrrolidine (CP-H, 0.1 mM). EPI induced a reduction in CF and in LVDP (P < 0.001). ISO infusion enhanced CF and RPP in the control group; in the EPI group, these increases were significantly impaired. Release of LDH was significantly increased during EPI infusion (P < 0.001). RONS was 2.5 times greater in the EPI group than in the control group (P < 0.05). In conclusion, a significant deterioration in cardiac function was observed after EPI perfusion and was associated with cellular injury and the generation of myocardial RONS. Further investigations are now needed to determine whether new cardioprotective agents targeting oxidative stress may reduce the incidence of anthracycline-induced cardiotoxicity.

Heart transplant is considered to be an extremely severe ischemia-reperfusion sequence. Post-ischemic dysfunction triggers multiple processes especially oxidative stress, but the mechanisms remain unclear. Free radical interactions lead to peroxynitrite generation, which seems to be involved in early post-transplant heart failure. The aim of this study was to evaluate the potential impact of a peroxynitrite decomposition catalyst: FeTPPS (5,10,15,20-tetrakis-[4-sulfonatophenyl]-porphyrinato-fer[III]) and pyruvate on myocardial functional recovery after cardioplegic arrest using an experimental protocol in rat hearts. Isolated working rat hearts were subjected to ischemia (4 h at 4 degrees C in cardioplegic solutions), followed by 45 min of reperfusion. Four groups were constituted: control, pyruvate: (2 mm) added to cardioplegic and Ringer-lactate solutions, FeTPPS: (10 microm) perfused during the reperfusion, and a combination of both treatments. Lactate dehydrogenase (LDH) activity was assessed during the reperfusion to evaluate the level of cardiac injury. Oxidative stress was evaluated on heart slices using a fluorescent probe: dihydroethidium, and the collagen content was assessed using picro-Sirius coloration. Global post-ischemic recovery in the control group was about 35% of pre-ischemic values. Results showed that addition of pyruvate led to an increase in myocardial function and to a decrease in LDH activity released during the reperfusion. FeTPPS protected against injury after cardioplegic arrest during reperfusion. No additive effect of the two treatments (pyruvate + FeTPPS) was observed. The collagen content was better preserved in the FeTPPS group than in the control and pyruvate groups. In conclusion, this study shows that peroxynitrite plays an important role in the functional and cellular alterations associated with cardiac ischemia-reperfusion sequences and confirms that pyruvate helped to preserve myocardial function. The use of the peroxynitrite decomposition catalyst (FeTPPS) may help to improve myocardial preservation during a prolonged ischemia sequence.

It has not been completely demonstrated if hypertension may, in part, develop as a result of increased oxidative stress (OS), inflammation and little is known about the short-term effects of antioxidant therapy. This study was designed to appreciate the effect of 7 days vitamin C-enriched diet (5 g/kg/day) on hemodynamic function and vascular OS in normotensive Wistar Kyoto rats and hypertensive rats (SHR). Aorta NAD(P)H oxidase activity was determinate and free radicals evaluated by electron spin resonance with a spin probe CP-H. Matrix metalloproteinase-1 (MMP-1) and monocyte chemoattractant protein-1 (MCP-1) expression were measured. The treatment with vitamin C did not change arterial pressure in SHR but prevented the increase in OS levels in SHR aortas. MMP-1 and MCP-1 expressions were more intense in the media of SHR aortas than in those of WKY rats but these expressions were not modified by vitamin C-pretreatment. Vitamin C-pretreatment was not able to protect heart against in vitro ischemia-reperfusion dysfunctions. These data may suggest that treatment with high doses of vitamin C in SHR can limit over-production of reactive oxygen species; however this effect was not accompanied with changes in arterial pressure and protection against I-R dysfunctions. Dissociation between vascular oxidative stress and cardiovascular function may be evoked.

The mechanisms of the adverse effects of free fatty acids on the ischemic-reperfused myocardium are not fully understood. Long-chain fatty acids, including palmitate, uncouple oxidative phosphorylation and should therefore promote the formation of oxygen-derived free radicals, with consequent adverse effects. Conversely, the antianginal agent trimetazidine (TMZ), known to inhibit cardiac fatty acid oxidation, could hypothetically lessen the formation of reactive oxygen species (ROS) and thus improve reperfusion mechanical function. Isolated perfused rat hearts underwent 30 min of total global ischemia followed by 30 min of reperfusion. Hearts were perfused with glucose 5.5 mmol/l or palmitate 1.5 mmol/l with or without TMZ (100 micromol/l). Ascorbyl free radical (AFR) release during perfusion periods was measured by electron spin resonance as a marker of oxidative stress. Post-ischemic recovery in the palmitate group of heart was lower than in the glucose group with a marked rise in diastolic tension and reduction in left ventricular developed pressure (Glucose: 85 +/- 11 mmHg; Palmitate: 10 +/- 6 mmHg; p0.001). TMZ decreased diastolic tension in both glucose- and in palmitate-perfused hearts. Release of AFR within the first minute of reperfusion was greater in palmitate-perfused hearts and in hearts perfused with either substrate, this marker of oxidative stress was decreased by TMZ (expressed in arbitrary units/ml; respectively: 8.49 +/- 1.24 vs. 1.06 +/- 0.70 p0.05; 12.47 +/- 2.49 vs. 3.37 +/- 1.29 p0.05). Palmitate increased the formation of ROS and reperfusion contracture. TMZ, a potential inhibitor of palmitate-induced mitochondrial uncoupling, decreased the formation of free radicals and improved postischemic mechanical dysfunction. The novel conclusion is that adverse effects of fatty acids on ischemic-reperfusion injury may be mediated, at least in part, by oxygen-derived free radicals.

Sudden cardiac death occurring in patients with end-stage renal disease (ESRD) may be related to poor autonomic function with a significant decreased heart-rate variability (HRV). In addition, coronary artery disease has a high prevalence in this population and accounts for 50% of deaths. In the present study, relationships between HRV and myocardial ischemic abnormalities revealed by myocardial scintigraphy (MS) were evaluated in 32 chronic hemodialysis patients.We prospectively studied 32 chronic hemodialysis patients. Each underwent MS and 24 h electrocardiography at baseline for analysis of time and frequency domain the day of dialysis. Three periods were analyzed: during dialysis session, the morning after (nondialytic period), and in a 24 h period. Patients were included in group 1 (seven women, 11 men; mean age: 62+/-19 years) when MS revealed no ischemia, whereas patients were included in group 2 (seven women, seven men; mean age: 63.1+/-20 years) when MS revealed ischemic lesions.A student+/-test revealed that during the nondialytic period, two important markers of HRV, percentage of delta RR50 ms (pNN50) (4.5+/-4.04 in group 1 versus 1.7+/-1.4 in group 2), and root mean square of delta RR (rMSSD) (27.7+/-13.4 versus 19.7+/-6.8) were significantly reduced in group 2 compared with values in group 1. No significant difference appears between the two groups for standard deviation of normal to normal intervals (SDNN), mean heart rate, and spectral analysis.Patients with ESRD and myocardial ischemia revealed by MS have reduced parasympathetic activity during the nondialytic period. Correlations between parameters of HRV and ischemic lesions revealed by MS have been shown for the first time.

Spin traps might exert antioxidant cardioprotective effects during myocardial ischaemia-reperfusion where free radicals are thought to be responsible for the occurrence of reperfusion injury. The aim of our study was to investigate the effects of two new alpha-phenyl N-tert-butylnitrone (PBN)-derived beta-phosphorylated nitrones: 2-N-oxy-N-[benzylidène amino] diéthyl propyl-2-phosphate (PPN) and 1-diethoxyphosphoryl-1-methyl-N-[(1-oxido-pyridin-1-ium-4-yl) methylidene] ethylamine N-oxide (4-PyOPN) compared with PBN on (1) the evolution of cardiovascular parameters and (2) the postischaemic recovery. Anaesthetized rats were injected with 120 micro mol/kg of the nitrones or 14 micro mol/kg of amiodarone, used as a reference antidysrhythmic drug. Ischaemia was induced in vivo through ligation of the left anterior descending coronary artery for 5 min followed by 15 min of reperfusion after release. Cardiovascular parameters and occurrence of ventricular premature beats (VPB), ventricular tachycardia (VT) and fibrillation (VF) were recorded throughout the experiment. Under nonischaemic conditions, none of the three spin traps was shown to modify cardiovascular parameters during the 25-min measurement period. Solvent-treated (NaCl 0.9%) animals challenged with ischaemia-reperfusion exhibited 39 +/- 10 VPB, 156 +/- 39 s of VT and 60% mortality caused by sustained VF. Nitrones improved slightly postischaemic recovery, reducing the occurrence of VF and mortality to 33% whereas amiodarone injection totally suppressed rhythm disturbances and mortality. Our study has shown only limited antidysrhythmic cardioprotective effects of PBN-derived beta-phosphorylated nitrones during reperfusion after a regional myocardial ischaemia but also minor antioxidant properties of these spin trapping agents.

Abstract The potential for imaging bed boundaries and fractures using the borehole acoustic reflection survey (BARS) technique is well documented. Traditionally, this type of imaging has been conducted with a monopole source and imaging the reflected P and the mode-converted transmission waves (Pto S and S to P). Recently the BARS methodology has been applied to shear data from a dipole source. Much of the published work is in an open-hole environment. In our case study a BARS image was acquired in a layered carbonate reservoir in a horizontal well behind casing. The objective was to acquire a base image prior to a planned hydraulic fracturing job for comparison with the post-fracturing image. Both, monopole and dipole data were used to do the imaging. Data acquired shows that the BARS technique overcame uncertainties associated with; arrival of the casing modes, cement conditions, attenuation of the reflected signal at the casing/cement/formation interfaces and provided reliable results behind casing up to a distance of 100 ft away from the well. Introduction BARS (Borehole Acoustic Reflection Survey) or SWI (Single Well Imaging) for detecting near borehole events at sub seismic scale was first demonstrated by Hornby in 1989. The methodology adopted involves imaging P waves from a monopole source. Later Yamamoto (1999) and other demonstrated that borehole crossing features could be imaged using S to P conversion downdip and P to S conversions updip of the event. More recently Tang and others (2009) demonstrated this methodology using dipole acoustic data. Published data does not show much experience of acoustic imaging in a cased well through a porous reservoir. A porous reservoir presents a highly attenuating environment making imaging "near borehole features", especially in a cased well very challenging. Acoustic imaging can be significantly beneficial if it can be successfully done in these environments. Successful imaging requires the reflected signal to have sufficient amplitude to differentiate it from noise. There are losses as a consequence of the formation Q and geometrical spreading which are well understood however a significant amount of energy is lost at energy transfers from tool to borehole, borehole to formation, formation to borehole and borehole to tool. These transfers are frequency dependent and difficult to predict by models. Numerical work has been done in past to predict radiation and reception pattern in a borehole but the work considers simple geometries as compared to the real conditions especially of a cased well scenario. In a cased borehole our biggest challenge is to transfer energy from the borehole to the formation. We propose that one way to overcome the uncertainty of the borehole transfers is to have a wideband transmitter with a range of frequencies of excitation. This would ensure that the preferred frequency for a particular geometry would most likely be excited and we would get good energy transfer at the interfaces.

Despite major improvements in the resuscitation of patients with head injury, the outcome of patients with head trauma often remains poor and difficult to establish. Heart rate variability (HRV) analysis is a noninvasive tool used to measure autonomic nervous system (ANS) activity. The aim of this prospective study was to investigate whether HRV analysis might be a useful adjunct for predicting outcome in patients with severe head injury. Twenty patients with severe head trauma (Glasgow Coma Scale [GCS]or= 8) underwent 24-hour electrocardiogram recording 1 day after trauma and again 48 hours after withdrawal of sedative drugs. Heart rate variability was assessed, in both time domain and spectral domain. The authors initially compared (on Day 1) HRV in patients who progressed to brain death to HRV in survivors; then during the awakening period compared HRV in surviving patients with good recovery (GCSor= 10) to HRV in patients characterized by a worsened neurologic state (GCS10). Statistical analysis used the Kruskal-Wallis test, P.05. To assess whether HRV could predict evolution to brain death, receiver operating characteristic (ROC) curves were generated the day after trauma for Total Power, natural logarithm of high-frequency component of spectral analysis (LnHF), natural logarithm of low-frequency component of spectral analysis (LnLF), and root mean square for successive interval differences (rMSSD). Seven patients died between Day 1 and Day 5 after trauma. Six of those had progressed to brain death. In these six patients, at Day 1, Global HRV and parasympathetic tone were significantly higher. Referring to the area under the rMSSD ROC curve, HRV might provide useful information in predicting early evolution of patients with severe head trauma. During the awakening period, global HRV and the parasympathetic tone were significantly lower in the worsened neurologic state group. In conclusion, HRV could be helpful as a predictor of imminent brain death and a useful adjunct for predicting the outcome of patients with severe head injury.

The consequences of a dietary n-3 PUFA supply was investigated on the blood pressure (BP) increase elicited by left renal artery stenosis in rats distributed in 3 groups (n = 8) fed for 8 weeks a semi-purified diet either as control diet or enriched diets (docosahexaenoic acid, DHA, or eicosapentaenoic acid, EPA). The PUFA intake induced large alterations in heart and kidney phospholipid fatty acid profile, but did not influence body weight, cardiac hypertrophy, renal left atrophy and right hypertrophy. Within 4 weeks, BP raised from 120-180 +/- 2 mm Hg in the control group, but only to 165 +/- 3 mm Hg in the n-3 PUFA groups. After stabilization of BP in the 3 groups, the rats received a short administration of increasing dose of perindopril. The lower dose (0.5 mg/kg) moderately decreased BP only in the control group. With higher doses (1, 5 and 10 mg/kg) BP was normalized in the 3 groups, with a higher amplitude of the BP lowering effect in the control group. A moderate n-3 PUFA intake can contribute to prevent the development of peripheral hypertension in rats by a mechanism that may involve angiotensin converting enzyme.

The purpose of this study was to modify the amount of 22:4 n-6, 22:5 n-6 and 20:5 n-3 in cardiac phospholipids and to evaluate the influence of these changes on the functioning of working rat hearts and mitochondrial energy metabolism under normoxic conditions and during postischemic reperfusion. The animals were fed one of these four diets: (i) 10% sunflower seed oil (SSO); (ii) 10% SSO + 1% cholesterol; (iii) 5% fish oil (FO, EPAX 3000TG, Pronova) + 5% SSO; (iv) 5% FO + 5% SSO + 1% cholesterol. Feeding n-3 PUFA decreased n-6 PUFA and increased n-3 PUFA in plasma lipids. In the phospholipids of cardiac mitochondria, this dietary modification also induced a decrease in the n-6/n-3 PUFA ratio. Cholesterol feeding induced marked hepatic steatosis (HS) characterized by the whitish appearance of the liver. It also brought about marked changes in the fatty acid composition of plasma and mitochondrial phospholipids. These changes, characterized by the impairment of deltaS- and delta6-desaturases, were more obvious in the SSO-fed rats, probably because of the presence of the precursor of the n-6 family (linoleate) in the diet whereas the FO diet contained large amounts of eicosapentaenoic and docosahexaenoic acids. In the mitochondrial phospholipids of SSO-fed rats, the (22:4 n-6 + 22:5 n-6) to 18:2 n-6 ratio was decreased by HS, without modification of the proportion of 20:4 n-6. In the mitochondrial phospholipids of FO-fed rats, the amount of 20:5 n-3 tended to be higher (+56%). Cardiac functioning was modulated by the diets. Myocardial coronary flow was enhanced by HS in the SSO-fed rats, whereas it was decreased in the FO-fed animals. The rate constant k012 representing the activity of the adenylate kinase varied in the opposite direction, suggesting that decreased ADP concentrations could cause oxygen wasting through the opening of the permeability transition pore. The recovery of the pump function tended to be increased by n-3 PUFA feeding (+22%) and HS (+45%). However, the release of ascorbyl free radical during reperfusion was not significantly modified by the diets. Conversely, energy production was increased by ischemia/reperfusion in the SSO group, whereas it was not modified in the FO group. This supports greater ischemia/reperfusion-induced calcium accumulation in the SSO groups than in the FO groups. HS did not modify the mitochondrial energy metabolism during ischemia/reperfusion. Taken together, these data suggest that HS- and n-3 PUFA-induced decrease in 22:4 and 22:5 n-6 and increase in 20:5 n-3 favor the recovery of mechanical activity during post-ischemic reperfusion.

UNLABELLED Physiology of brain death is characterized by major disturbances of autonomic nervous system (ANS) activity which can lead to graft dysfunction. These findings exhibit the importance of early diagnosis of brain death to improve transplantation outcome. The aim of this prospective study was to assess whether heart rate variability (HRV) analysis, a noninvasive method to investigate ANS activity in comatose patients, could achieve this goal. A total of 14 brain-injured patients were included in the study as soon as they exhibited the clinical signs of imminent brain death. The electrocardiogram was then recorded from two leads with a Holter digital monitor. The clinical diagnosis of brain death was considered after an autonomic storm had occurred. HRV was assessed from 6 h before to 6 h after brain death in both time domain and spectral analysis, estimating either global ANS activity (index of variability, total power), parasympathetic activity (percentage of delta of R-R interval >50 ms, root mean square for successive interval differences, LnHF) or sympathetic activity (LnLF). Hourly averages of these variables were compared by using one-way analysis of variance. To assess whether HRV could per se diagnose brain death, receiver operating characteristic curves were generated for total power, root mean square for successive interval differences, and LnHF. We observed, for 6 h before brain death, a progressive extinction of the influence of the ANS on cardiovascular regulation. There was no activity in the two components of the ANS as soon as brain death occurred. HRV analysis appeared to be a very sensitive but a less specific method of diagnosing brain death. IMPLICATIONS A total of 14 brain-injured patients with the clinical criteria of imminent brain death were enrolled for electrocardiogram recording and heart rate variability analysis (a noninvasive method to investigate autonomic nervous system activity). For 6 h before brain death, we observed a progressive extinction of autonomic nervous system activity which was not present as soon as brain death was clinically evoked.

This work aimed to improve the knowledge and the control of interactions between lactic acid bacteria (LAB) and propionibacteria (PAB) in order to control the propionic acid fermentation in European hard cheeses, and therefore their quality. Among more than 50 couples of strains LAB/PAB used in cheese making, some pairs of strains were chosen in function of quality results on cheeses (sensorial analysis). A whey model system and an alternative conductimetric method, with good reproducibility were used to study interactions. The lipolytic activity of PAB strains varied by a factor 4 to 5. The aroma of ripened Emmental cheese was linked to the level and the type of lipolysis in the cheese, correlated with lipolytic activity of PAB. The main pathways of the utilisation of lactate by PAB, studied by 13 C RMN, were useful to understand the balance between final products: acetic, propionic acid, CO 2 .

This study was carried out in order to determine if the efficiency of amiodarone, a class III antiarrhythmic agent, is associated with changes in mitochondrial oxidative phosphorylation. A population of 30 rats were treated with amiodarone (100 mg/kg/day) for 5 days. A second population receiving only vehicle was used as control. The hearts were perfused according to the working mode. After 15 min of normoxic perfusion, the left main coronary artery was ligated and the ligation was maintained for 20 min. The ligation was removed and reperfusion continued for a further 30 min. The electrocardiogram was monitored continuously. At the end of perfusion, the ischemic and non ischemic areas were visually separated and mitochondria were harvested from each area. Their oxidative and energy metabolism were assessed with palmitoylcarnitine as substrate in 2 respiration media differing in their free calcium concentration (0 or 0.34 μm). In normoxic conditions, amiodarone treatment increased the cardiac metabolic efficiency (mechanical work to oxygen consumption ratio). The local ischemia decreased the aortic and coronary flows without modifying the cardiac metabolic efficiency. Amiodarone treatment maintained the aortic flow at a significantly higher value; the duration of severe arrhythmias was significantly decreased by the drug. The reperfusion of the ischemic area allowed the partial recovery of fluid dynamics. The coronary flow was restored to 89% of the pre ischemic value. Conversely, the aortic flow never exceeded that measured at the end of ischemia, partly due to the important development of severe arrhythmias. The recovery of aortic flow and metabolic efficiency during reperfusion was improved by amiodarone treatment; ventricular tachycardia and fibrillation duration were reduced. In the mitochondria issued from the normoxic area, the energy metabolism was not altered by the amiodarone treatment, but the presence of calcium in the respiration medium modified the oxidative phosphorylation. The divalent cation slightly decreased the state III respiration rate and increased noticeably the state IV respiration rate. This was associated with an important mitochondrial AMP production and maintenance of ADP in the respiration medium. This energy wasting was reported to decrease the mitochondrial metabolic efficiency. After an ischemia-reperfusion sequence, mitochondrial oxidation phosphorylation was reduced and amiodarone treatment amplified this decrease. This was presumably due to an increased mitochondrial calcium accumulation. Thus, the beneficial properties of amiodarone during reperfusion are supposed to be due to a protection against the deleterious effect of excess matrix calcium on mitochondrial energy metabolism.

International audience; The influence of dietary n-6 and n-3 polyunsaturated fatty acids (PUFA) on heart pump function and mitochondrial energy metabolism was investigated before and after ischemia. Weanling male Wistar rats were fed for 8 weeks a diet containing either 10% of sunflower seed oil (SSO group) or 10% of a 1:1 (w/w) mixture of fish oil and sunflower seed oil (FO group). The hearts were perfused according to the working mode for 15 min with a Krebs-Henseleit medium containing glucose (11 mM), insulin (10 IU/L) and caprylic acid (25 microM). They were then either maintained in normoxic conditions (70 min) or subjected to a global no-flow normothermic ischemia (20 min) followed by reperfusion (50 min). The aortic and coronary flows were monitored at 5-min intervals. The lactate dehydrogenase (LDH) release in the coronary effluent was evaluated in the control hearts and during ischemia/reperfusion. At the end of the perfusion, two subpopulations of mitochondria were prepared from each heart, by either mechanical or enzyme extraction (ME and EE mitochondria, respectively). The succinate dehydrogenase (SDH) activity was evaluated. Furthermore, the respiration parameters were assessed with either glutamate (20 mM) or palmitoylcarnitine (25 microM) as substrate. Substituting sunflower seed oil by fish oil in the diet provoked a large decrease in the n-6/n-3 PUFA ratio of cardiac phospholipids. The n-3 PUFA enrichment did not alter the coronary and aortic flows nor the LDH release in physiological conditions. Conversely, during post-ischemic reperfusion, the increased amount of n-3 PUFA improved the recovery of aortic flow and decreased the LDH release, without affecting significantly the coronary flow. In ME and EE mitochondria, the phospholipid n-6/n-3 PUFA ratio was similarly modified by the dietary manipulations. The analysis of total cardiac SDH activity suggested an ischemia-induced oedema, of similar magnitude in the two dietary groups. However, neither dietary manipulations nor ischemia influenced the mitochondrial extraction. Similarly, the parameters of glutamate oxidation were also unaffected. Conversely, with palmitoylcarnitine, post-ischemic reperfusion induced a decrease in both state III respiration rate and energy production which were more important in the EE mitochondria of the SSO group. These results suggest that the recovery of mitochondrial energy metabolism and myocardial pump function during reperfusion may be improved in n-3 PUFA-rich hearts. This could be related to a lower injury in n-3 PUFA-rich membranes. Since cardiac function in physiological conditions was not affected by the diet, fish oil could be considered as a beneficial factor to limit heart injury during ischemia and reperfusion.

Cet article s’inscrit au coeur du débat sur la nature du partenariat école-famille-communauté et sur ses logiques sous-jacentes. Nous y contribuons en questionnant les fondements et les usages de l’écosystémie qui est, en principe, à la base des pratiques collaboratives et de l’engagement parental. En situant l’écosystémie au regard de la notion de métathéorie, nous inscrirons les pratiques collaboratives sur un continuum qui reflète la nature et le degré d’interaction entre les acteurs. Nous prenons position au chapitre du partenariat école-famille-communauté en adoptant une perspective écosystémique d’orientations contextuelle et socioculturelle. Nous nous appuierons sur le programme Famille, école, communauté, réussir ensemble (FECRE), mis en oeuvre au Québec entre 2002 et 2009, pour illustrer l’actualisation d’une telle logique écosystémique dans le cadre de pratiques collaboratives ainsi que de l’engagement parental., In this article, we explore the heart of the debate on the nature of the school-family-community partnership and its underlying rationales. We challenge the underpinnings and uses of the ecosystem which is considered at the root of collaborative practices and parental engagement. By inserting the ecosystem into a metatheory, we place collaborative practices along a continuum that reflects the nature and the degree of interactions between those engaged. Our standpoint looks at this partnership in relation to an ecosystemic perspective that is based on contextual and sociocultural perspective. To illustrate how such an ecosystemic logic can be applied to collaborative practices and parental engagement, we refer to the program Famille, école, communauté, réussir ensemble (FECRE), which was implemented in the province of Quebec between 2002 and 2009.

International audience; This study was designed to evaluate the effects of individual dietary long-chain n-3 polyunsaturated fatty acids (LCPUFA) on hypertension and cardiac consecutive disorders in spontaneously hypertensive rats (SHR) as compared to Wistar-Kyoto rats (WKY). Rats were fed for 2 months an eicosapentaenoic (EPA)- or docosahexaenoic acid (DHA)-rich diet (240 mg/day) or an n-3 PUFA-free diet. Male SHR (n=6), implanted with cardiovascular telemetry devices, were housed in individual cages for continuous measurements of cardiovascular parameters (blood pressure (BP) and heart rate (HR)) during either activity or rest periods, ECG were recorded during the quiet period. The n-6 PUFA upstream of arachidonic acid was affected in SHR tissues. The cardiac phospholipid fatty acid profile was significantly affected by dietary DHA supply, and EPA in a very lower extent, since DHA only was incorporated in the membranes instead of n-6 PUFAs. Endothelium n-6 PUFA content increased in all SHR groups. Compared to WKY, linoleic acid content decreased in both studied tissues. Cardiac noradrenalin decreased while the adrenal catecholamine stores decreased in SHR as compared to WKY. Both n-3 PUFA supply induced a decrease of adrenal catecholamine stores. Nevertheless after 6 weeks, DHA but not EPA induced a lowering-blood pressure effect and shortened the QT interval in SHR, most probably through its tissue enrichment and a specific effect on adrenergic function. Dietary DHA supply retards blood pressure development and has cardioprotective effect. These findings, showing the cardioprotective effects of DHA in living animals, were obtained in SHR, but may relate to essential hypertension in humans.

The natural reserve of the Marais de Lavours (460 hectares), lying between the lake of Bourget and the Rhône, plays an important role in regulating water flow. It is also the site of a various rare animal species. In the past, this area was integrated into the local economy (haymaling, digging of peat), but progresively this marsh has been abandoned and then spoilt by improvement works to the Rhône. Such change has resulted in the area becoming more isolated and uniform in character. To maintain the diversity necessary to allow the survival of the area's different species, the managers of the Reserve has introduced on an experimental basis Highland cattle and horses from the Camargue. The animals appear to have acclimatised to the area with relatively little help, and their action on the environment corresponds withe expectations of the Reserv's managers. Nevertheless, longer terms problems of the "natural" management of this situation remain., La Réserve Naturelle du Marais de Lavours (460 hectares) située entre le lac du Bourget et le Rhône, joue un rôle important dans la régulation des flux hydriques. Elle abrite également plusieurs espèces rares. Autrefois intégré à l'économie locale (coupes de foin, extraction de tourbe), le marais a été progressivement délaissé puis altéré par les travaux d'aménagement du Rhône. Ce changement se traduit par une fermeture progressive du milieu et par son uniformisation. Pour maintenir la diversité nécessaire au maintien de nombreuses espèces, les responsables de la Réserve ont introduit à titre expérimental des vaches Highland Cattle et des chevaux Camargue. Ce bétail semble s'acclimater sous réserve d'interventions légères. Son action sur le milieu s'avère conforme à l'attente du gestionnaire. Se pose tout de même le problème des logiques d'une gestion naturelle à long terme., Pautou Guy, Majchrzak Yves, Manneville Olivier, Gruffaz René, Moreau Daniel. Dynamique de la végétation et gestion de la réserve naturelle du marais de Lavours (Ain) / Vegetation dynamics and the management of the natural reserve of the Marais de Lavours . In: Revue de géographie de Lyon, vol. 66, n°1, 1991. Connaissance de la friche. pp. 61-70.

Objective— Asymmetrical dimethylarginine (ADMA) is an endogenous competitive inhibitor of nitric oxide (NO) synthases. From a prospective cohort of patients with acute myocardial infarction (MI), we aimed to analyze the predictive value of circulating ADMA concentrations on prognosis. Methods and Results— Blood samples from 249 consecutive patients hospitalized for acute MI R 2 =0. 25). Baseline ADMA levels were higher in patients who had died than in patients who were alive at 1 year follow-up (1.23 [0.98 to 1.56] versus 0.95 [0.77 to 1.20] μmol/L, P Conclusion— Our study suggests that the baseline ADMA level has a strong prognostic value for mortality after MI, beyond traditional risk factors and biomarkers.

Heart rate variability (HRV), which is considered to reflect the activity of the autonomic nervous system (ANS), has been shown to decline with age. The aim of the present study was to explore cardiac ANS in older patients showing frontal-subcortical dysfunction with "Psychomotor Disadaptation Syndrome" (PDS), through the 24-h HRV. We enrolled 14 patients with PDS (mean age: 84.5+/-6.9 years), they were compared to 13 frail control subjects (mean age: 80.6+/-6.7 years). Cardiac ANS activity was assessed by 24-h ECG recordings from three leads with a Holter digital monitor. The decrease in cardiac ANS activity observed in PDS subjects was greater than the alteration found in normally aging subjects. The abnormalities of ANS that aggravate the effects of aging can be seen as a type of physical deconditioning. Such patients could benefit from particular attention in physical training.

Background . From a prospective cohort of patients with acute myocardial infarction (MI), we aimed to analyse the predictive value of ADMA concentrations on mortality at 1 year follow-up. ADMA is an endogenous competitive inhibitor of NO synthases. Patients . Blood samples from 204 consecutive patients hospitalised for acute MI < 24 hr were taken on admission. Serum levels of ADMA, its stereoisomer, symmetric dimethylarginine (SDMA), were determined using high-performance liquid chromatography and fluorescence. Results . The mean (SD) ADMA level was 1.07(0.37) μmol/L. ADMA was positively related to age, homocysteine, SDMA and L-arginine. The glomerular filtration rate (GFR) showed a trend toward an inverse relation with ADMA. ADMA concentrations showed a trend towards a higher level in women than in men (p=.101) and were lower in current smokers vs past or non smokers (p=0.022). Baseline ADMA and SDMA levels were higher in patients who had died than in patients who were alive at 1 year follow-up (respectively 1.22(1.06–1.54) vs 0.98(0.78–1.24), p=0.012 and 0.77(0.54–1.03) vs 0.47(0.35–0.64), p Conclusion . Our study suggests that measurement of ADMA levels at baseline improves cardiovascular risk prediction after acute MI, beyond traditional risk factors and biomarkers. ADMA may thus constitute a novel and useful marker for risk stratification in acute MI.

International audience; The present study was designed to evaluate whether long-term intake of dietary alpha-linolenic acid (ALA), supplied as whole grain-extruded linseed, can increase endogenous production of n-3 long-chain polyunsaturated fatty acids (FAs) in healthy adult rats and influence the heart rate (HR) and adrenergic response in the same way as docosahexaenoic acid (DHA)-rich diets. DHA enrichment was evaluated using FA analysis of tissue phospholipids after 8, 16, 24, and 32 wk of feeding in male Wistar rats randomly assigned to three dietary groups (n = 8 in each group): a reference fat diet (RFD), an ALA-rich (ALA) diet, and a DHA-rich (DHA) diet. At 1 wk before the animals were killed, under anesthesia, HR was measured from ECG recordings during an adrenergic stimulation challenge (n = 8). There was a significant increase of DHA in the cardiac membrane in the ALA group compared with the RFD group. DHA content in the cardiac membrane was approximately 10% in the ALA group vs. 20% in the DHA group and 4% in the RFD group. The cardiac FA profile was established after 2 mo and remained essentially unchanged thereafter. Regardless of the diet, DHA in the heart decreased with age. Nevertheless, DHA content in the heart remained at >15% in the DHA group and remained greater in older rats fed the ALA diet than in younger RFD-fed rats. Basal HR decreased in the ALA group (395 +/- 24.9 beats/min) to a level between that of the DHA and RFD groups (375 +/- 26.4 and 407 +/- 36.7 beats/min, respectively). Both n-3 dietary intakes contribute to enhancement of the chronotropic response to adrenergic agonist stimulation. Regulation of HR by neurohumoral mediators may be controlled by lower content of DHA, e.g., by a dietary supply of extruded linseed (ALA).

Defining the substrate that influences the most favourably the myocardial post-ischemic recovery is subject of debates, due to dissociation between functional and biochemical benefits. Hence, we studied the effects of either glucose or different fatty acids on the functional and metabolic recovery of post-ischemic cardiomyocytes in a substrate-free hypoxia model of simulated ischemia-reperfusion. Rat cardiomyocytes were submitted to a 2.5 h simulated ischemia followed by a 2 h reoxygenation without substrate (control), or with either glucose, octanoic acid, oleic acid, or elaidic acid. During simulated ischemia, electromechanical function gradually disappeared while the cellular viability and mitochondrial function declined. During control simulated reperfusion, cardiomyocytes recovered near normal function but a significant reduction in the action potential amplitude and rate persisted. The addition of glucose or oleic acid during simulated reperfusion promoted a faster, better and sustain functional recovery. Amongst the fatty acids, the functional recovery was slower with elaidic and octanoic acids as compared with oleic acid. The mitochondrial function was better improved during simulated reperfusion with glucose than with the tested fatty acids, among which elaidic acid was the less unfavourable. Paradoxically, the addition of whichever substrate during simulated reperfusion tended to worsen the cellular viability. Thus, cardiomyocytes recovery strongly relies on the characteristics of the substrate supplied at the onset of simulated reperfusion: glucidic or lipidic nature, chain-length, insaturation degree. Moreover, these data suggest that defining the appropriateness of a given substrate for the post-ischemic cardiomyocyte recovery is closely related to the functional and the biological endpoints in consideration.

New onset atrial fibrillation (AF) is a common complication of acute myocardial infarction (MI), with a prevalence ranging of from 7–18%, and is associated with a higher incidence of in-hospital congestive heart failure. AF occurs in patients who are older with severe coronary artery disease and is associated with higher 30 day and one year mortality rates than for those patients without AF.1–4 However, most studies have been performed on data collected from patients with ST elevation myocardial infarction (STEMI). In the present study, we examined the characteristics and in-hospital outcome for a non-selected population, hospitalised for non-ST elevation myocardial infarction (NSTEMI) and included in the French regional RICO survey. From 1 January 2001 to 31 July 2003 pre-hospital as well as in-hospital data from 504 patients, hospitalised for acute NSTEMI in one region of eastern France, were analysed. All the cardiology departments of the region, five public hospitals and one private clinic, in charge of cardiac emergencies, participated in the study. All patients included in the study presented with NSTEMI. The diagnoses were based on: an increase in troponin concentrations to the upper limit of normal (ULN) or creatine kinase myocardial band ⩾ 2 ULN; NSTEMI (ST segment depression or negative T wave on ECG); patients admitted to index hospital within 24 hours following symptom onset. Patients presenting any one of the following criteria were excluded from the study: persistent ST elevation or new Q …

Although a large number of key odorants of Swiss-type cheese result from amino acid catabolism, the amino acid catabolic pathways in the bacteria present in these cheeses are not well known. In this study, we compared the in vitro abilities of Lactobacillus delbrueckii subsp. lactis , Lactobacillus helveticus, and Streptococcus thermophilus to produce aroma compounds from three amino acids, leucine, phenylalanine, and methionine, under mid-pH conditions of cheese ripening (pH 5.5), and we investigated the catabolic pathways used by these bacteria. In the three lactic acid bacterial species, amino acid catabolism was initiated by a transamination step, which requires the presence of an α-keto acid such as α-ketoglutarate (α-KG) as the amino group acceptor, and produced α-keto acids. Only S. thermophilus exhibited glutamate dehydrogenase activity, which produces α-KG from glutamate, and consequently only S. thermophilus was capable of catabolizing amino acids in the reaction medium without α-KG addition. In the presence of α-KG, lactobacilli produced much more varied aroma compounds such as acids, aldehydes, and alcohols than S. thermophilus, which mainly produced α-keto acids and a small amount of hydroxy acids and acids. L. helveticus mainly produced acids from phenylalanine and leucine, while L. delbrueckii subsp. lactis produced larger amounts of alcohols and/or aldehydes. Formation of aldehydes, alcohols, and acids from α-keto acids by L. delbrueckii subsp. lactis mainly results from the action of an α-keto acid decarboxylase, which produces aldehydes that are then oxidized or reduced to acids or alcohols. In contrast, the enzyme involved in the α-keto acid conversion to acids in L. helveticus and S. thermophilus is an α-keto acid dehydrogenase that produces acyl coenzymes A.