Ageing, Muscle Power and Physical Function: A Systematic Review and Implications for Pragmatic Training Interventions.

BACKGROUND: The physiological impairments most strongly associated with functional performance in older people are logically the most efficient therapeutic targets for exercise training interventions aimed at improving function and maintaining independence in later life. OBJECTIVES: The objectives of this review were to (1) systematically review the relationship between muscle power and functional performance in older people; (2) systematically review the effect of power training (PT) interventions on functional performance in older people; and (3) identify components of successful PT interventions relevant to pragmatic trials by scoping the literature. METHODS: Our approach involved three stages. First, we systematically reviewed evidence on the relationship between muscle power, muscle strength and functional performance and, second, we systematically reviewed PT intervention studies that included both muscle power and at least one index of functional performance as outcome measures. Finally, taking a strong pragmatic perspective, we conducted a scoping review of the PT evidence to identify the successful components of training interventions needed to provide a minimally effective training dose to improve physical function. RESULTS: Evidence from 44 studies revealed a positive association between muscle power and indices of physical function, and that muscle power is a marginally superior predictor of functional performance than muscle strength. Nine studies revealed maximal angular velocity of movement, an important component of muscle power, to be positively associated with functional performance and a better predictor of functional performance than muscle strength. We identified 31 PT studies, characterised by small sample sizes and incomplete reporting of interventions, resulting in less than one-in-five studies judged as having a low risk of bias. Thirteen studies compared traditional resistance training with PT, with ten studies reporting the superiority of PT for either muscle power or functional performance. Further studies demonstrated the efficacy of various methods of resistance and functional task PT on muscle power and functional performance, including low-load PT and low-volume interventions. CONCLUSIONS: Maximal intended movement velocity, low training load, simple training methods, low-volume training and low-frequency training were revealed as components offering potential for the development of a pragmatic intervention. Additionally, the research area is dominated by short-term interventions producing short-term gains with little consideration of the long-term maintenance of functional performance. We believe the area would benefit from larger and higher-quality studies and consideration of optimal long-term strategies to develop and maintain muscle power and physical function over years rather than weeks

COXOPATHIES DE LA GROSSESSE (ANALYSE DES CAS OBSERVES DANS UN SERVICE DE RHUMATOLOGIE)

AIX-MARSEILLE2-BU Méd/Odontol. (130552103) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Chromium(II)-Catalyzed Amination of N-Heterocyclic Chlorides with Magnesium Amides

International audienceWe report a ligand-free chromium(II)-catalyzed amination reaction of various N-heterocyclic chlorides. CrCl 2 regioselectively cata-lyzes the reaction of chloropyridines and dichloropyridines, dichloro-quinolines, dichloroisoquinolines and dichloroquinoxalines with a range of aliphatic, allylic, benzylic and saturated (hetero)cyclic magnesium amides in the presence of lithium chloride as additive. The reactions were performed at 50 °C in THF and led to the desired aminated products in 56-96% yield. The syntheses of amino-substituted heterocycles are of the utmost importance for the pharmaceutical and agro-chemical industries due to their high biological activity. 1 These molecules are generally prepared by nucleophilic aromatic substitution 2 but transition metal catalysts for ami-nations have also been intensively studied. 3 In 1983, Migita performed the coupling of aryl bromides with tin amides in the presence of a palladium catalyst. 4 More recently, since 1994, Buchwald 5 and Hartwig 6 have revolutionized this field by developing new classes of ligands and highly active palladium catalysts, which allowed a broad range of amina-tion reactions. With the objective of replacing costly palladium and sensitive phosphine ligands, we studied economic, lowly toxic and readily available transition metals catalysts for amination reactions. Previously, we reported the chromi-um(II) chloride 7 catalyzed cross-couplings between (hetero)-aryl halides and (hetero)aryl Grignard reagents under mild and ligand-free conditions. 8 Additionally, direct arylation of pyridines, aryl oxazolines and imines with various aryl-magnesium reagents was promoted by the presence of CrCl 2 as catalyst. 9 Herein we report the chromium(II)-catalyzed amination of N-heterocyclic chlorides with magnesium amides affording a range of aminated pyridines, quinolines and quinoxal-ines. In preliminary experiments, we examined the transition metal -catalyzed amination of 2-chloropyridine (1a) with magnesium chloride pyrrolidin-1-ide (2a), which was prepared by the deprotonation of pyrrolidine (4) with i-PrMgCl in THF at 0 °C and was warmed to 23 °C over one hour (Table 1). 10 The resulting magnesium amide displayed a good thermic stability and a good solubility under the reaction conditions. In the absence of any catalyst, only 13% of the aminated product (3a) was observed at 23 °C after 20 hours of reaction time (entry 1). However, when the Grignard reagent was prepared with an equimolar amount of lithium chloride as additive (use of i-PrMgCl·LiCl), 11 the conversion was increased and 27% of the pyridine 3a was detected by calibrated GC analysis (en-try 2). The use of 3% FeBr 3 or 3% CoCl 2 under the same conditions did not improve the amination (14-12%, entries 3 and 4). Nevertheless, in the presence of 3% CrCl 2 , 3a was obtained in 72% yield, which was improved to 77% using 10% of catalyst (entries 5 and 6). Performing the latter experiment without lithium chloride led to the formation of noticeably less product (64%, entry 7). In an attempt to further accelerate the reaction, the amination was then performed at 50 °C with 10 mol% of chromium(II) chloride. In the presence of 2.0 equivalents of LiCl, the aminated product 3a was isolated in 95% yield, whereas 3a was obtained in only 60% yield without additive (entries 8 and 9). Other chromium catalysts [CrCp 2 , 12 Cr(acac) 3 , 13 CrBr 2 14 ] led to somewhat lower yields (45-81%, entries 10-13). Performing this reaction at 50 °C for three hours without catalyst in the presence of LiCl produced the aminated pyridine 3a in 43% yield and, without LiCl, in 27% yield, confirming the importance SYNLETT0 9 3 6-5 2 1 4 1 4 3 7-2 0 9

Perturbation During Treadmill Training Improves Dynamic Balance and Gait in Parkinson’s Disease: A Single-Blind Randomized Controlled Pilot Trial

Background. Gait and balance dysfunction are major symptoms in Parkinson’s disease (PD). Treadmill training improves gait characteristics in this population but does not reflect the dynamic nature of controlling balance during ambulation in everyday life contexts. Objective. To evaluate whether postural perturbations during treadmill walking lead to superior effects on gait and balance performance compared with standard treadmill training. Methods. In this single-blind randomized controlled trial, 43 PD patients (Hoehn & Yahr stage 1-3.5) were assigned to either an 8-week perturbed treadmill intervention (n = 21) or a control group (n = 22) training on the identical treadmill without perturbations. Patients were assessed at baseline, postintervention, and at 3 months’ follow-up. Primary endpoints were overground gait speed and balance (Mini-BESTest). Secondary outcomes included fast gait speed, walking capacity (2-Minute Walk Test), dynamic balance (Timed Up-and-Go), static balance (postural sway), and balance confidence (Activities-Specific Balance Confidence [ABC] scale). Results. There were no significant between-group differences in change over time for the primary outcomes. At postintervention, both groups demonstrated similar improvements in overground gait speed (P = .009), and no changes in the Mini-BESTest (P = .641). A significant group-by-time interaction (P = .048) existed for the Timed Up-and-Go, with improved performance only in the perturbation group. In addition, the perturbation but not the control group significantly increased walk ing capacity (P = .038). Intervention effects were not sustained at follow-up. Conclusions. Our primary findings suggest no superior effect of perturbation training on gait and balance in PD patients. However, some favorable trends existed for secondary gait and dynamic balance parameters, which should be investigated in future trials

Acute Neuromuscular Adaptations in the Postural Control of Patients with Parkinson’s Disease after Perturbed Walking

Patients suffering from Parkinson’s disease (PD) present motor impairments reflected in the dynamics of the center of pressure (CoP) adjustments during quiet standing. One method to study the dynamics of CoP adjustments is the entropic half-life (EnHL), which measures the short-term correlations of a time series at different time scales. Changes in the EnHL of CoP time series suggest neuromuscular adaptations in the control of posture. In this study, we sought to investigate the immediate changes in the EnHL of CoP adjustments of patients with PD during one session of perturbed (experimental group) and unperturbed treadmill walking (control group). A total of 39 patients with PD participated in this study. The experimental group (n = 19) walked on a treadmill providing small tilting of the treadmill platform. The control group (n = 20) walked without perturbations. Each participant performed 5-min practice followed by three 5-min training blocks of walking with or without perturbation (with 3-min resting in between). Quiet standing CoP data was collected for 30 s at pre-training, after each training block, immediately post-training, and after 10 min retention. The EnHL was computed on the original and surrogates (phase-randomized) CoP signals in the medio-lateral (ML) and anterior–posterior (AP) directions. Data was analyzed using four-way mixed ANOVA. Increased EnHL values were observed for both groups (Time effect, p < 0.001) as the intervention progressed, suggesting neuromuscular adaptations in the control of posture. The EnHL of surrogate signals were significantly lower than for original signals (p < 0.001), confirming that these adaptations come from non-random control processes. There was no Group effect (p = 0.622), however by analyzing the significant Group by Direction by Time interaction (p < 0.05), a more pronounced effect in the ML direction of the perturbed group was observed. Altogether, our findings show that treadmill walking decreases the complexity of CoP adjustments, suggesting neuromuscular adaptations in balance control during a short training period. Further investigations are required to assess these adaptations during longer training intervals

Management of antiplatelet therapy in patients undergoing elective invasive procedures. Proposals from the French Working Group on perioperative haemostasis (GIHP) and the French Study Group on thrombosis and haemostasis (GFHT). In collaboration with the French Society for Anaesthesia and Intensive Care Medicine (SFAR).

The French Working Group on Perioperative Haemostasis (GIHP) and the French Study Group on Haemostasis and Thrombosis (GFHT) in collaboration with the French Society for Anaesthesia and Intensive Care Medicine (SFAR) drafted up-to-date proposals for the management of antiplatelet therapy in patients undergoing elective invasive procedures. The proposals were discussed and validated by a vote; all proposals but one could be assigned with a high strength. The management of antiplatelet therapy is based on their indication and the procedure. The risk of bleeding related to the procedure can be divided into high, moderate and low categories depending on the possibility of performing the procedure in patients receiving antiplatelet agents (none, monotherapy and dual antiplatelet therapy respectively). If discontinuation of antiplatelet therapy is indicated before the procedure, a last intake of aspirin, clopidogrel, ticagrelor and prasugrel 3, 5, 5 and 7 days before surgery respectively is proposed. The thrombotic risk associated with discontinuation should be assessed according to each specific indication of antiplatelet therapy and is higher for patients receiving dual therapy for coronary artery disease (with further refinements based on a few well-accepted items) than for those receiving monotherapy for cardiovascular prevention, for secondary stroke prevention or for lower extremity arterial disease. These proposals also address the issue of the potential role of platelet functional tests and consider management of antiplatelet therapy for regional anaesthesia, including central neuraxial anaesthesia and peripheral nerve blocks, and for coronary artery surgery

Gestion des agents antiplaquettaires en cas de procédure invasive non programmée ou d’hémorragie. Propositions du Groupe d’intérêt en hémostase périopératoire (GIHP) et du Groupe français d’études sur l’hémostase et la thrombose (GFHT) en collaboration avec la Société française d’anesthésie et de réanimation (SFAR)

Le Groupe d’intérêt en hémostase périopératoire (GIHP) et le Groupe français d’études sur l’hémostase et la thrombose (GFHT), en collaboration avec la Société française d’anesthésie et de réanimation (SFAR) ont fait des propositions de gestion des agents antiplaquettaires (AAP) pour une procédure invasive programmée. Ces propositions ont été discutées et validées par vote ; toutes sauf une ont fait l’objet d’un accord fort. La gestion des AAP dépend de leur indication et de la procédure considérée. Le risque hémorragique lié à la procédure invasive peut être divisé en bas, intermédiaire ou élevé, selon la possibilité ou non de réaliser la procédure sous traitement (sous respectivement bithérapie antiplaquettaire, aspirine en monothérapie ou aucun AAP). Si une interruption des AAP est indiquée avant la procédure, une dernière prise d’aspirine, clopidogrel, ticagrélor et prasugrel 3, 5, 5 et 7 jours avant la procédure est proposée. Le risque thrombotique associé à l’interruption des AAP doit être évalué en fonction de l’indication des AAP. Il est plus élevé chez les patients traités par bithérapie pour un stent coronaire que chez ceux traités par monothérapie pour une prévention cardiovasculaire, un antécédent d’accident vasculaire cérébral ischémique ou une artériopathie oblitérante des membres inférieurs. Ces propositions concernent aussi le rôle potentiel des tests fonctionnels plaquettaires, la gestion des AAP pour l’anesthésie locorégionale, centrale et périphérique, et pour la chirurgie cardiaque coronaire

In Reply

We appreciate the interest of Lagier et al. in our article.1 The authors highlighted in their letter the work of Montaigne et al.,2 who have recently published on the circadian rhythm in relation to ischemia reperfusion injury in a single-center retrospective propensity-matched cohort study addressing this subject on 596 (matched-pairs) patients undergoing aor-tic valve replacement with or without coronary artery bypass grafting, together with a single-center randomized study in 88 patients undergoing isolated aortic valve replacement, in which the perioperative myocardial injury has been assessed with the geometric mean of perioperative cardiac troponin T release

Effect of xenon anesthesia compared to sevoflurane and total intravenous anesthesia for coronary artery bypass graft surgery on postoperative cardiac troponin release. an international, multicenter, phase 3, single-blinded, randomized noninferiority trial

Abstract BACKGROUND: Ischemic myocardial damage accompanying coronary artery bypass graft surgery remains a clinical challenge. We investigated whether xenon anesthesia could limit myocardial damage in coronary artery bypass graft surgery patients, as has been reported for animal ischemia models. METHODS: In 17 university hospitals in France, Germany, Italy, and The Netherlands, low-risk elective, on-pump coronary artery bypass graft surgery patients were randomized to receive xenon, sevoflurane, or propofol-based total intravenous anesthesia for anesthesia maintenance. The primary outcome was the cardiac troponin I concentration in the blood 24 h postsurgery. The noninferiority margin for the mean difference in cardiac troponin I release between the xenon and sevoflurane groups was less than 0.15 ng/ml. Secondary outcomes were the safety and feasibility of xenon anesthesia. RESULTS: The first patient included at each center received xenon anesthesia for practical reasons. For all other patients, anesthesia maintenance was randomized (intention-to-treat: n = 492; per-protocol/without major protocol deviation: n = 446). Median 24-h postoperative cardiac troponin I concentrations (ng/ml [interquartile range]) were 1.14 [0.76 to 2.10] with xenon, 1.30 [0.78 to 2.67] with sevoflurane, and 1.48 [0.94 to 2.78] with total intravenous anesthesia [per-protocol]). The mean difference in cardiac troponin I release between xenon and sevoflurane was -0.09 ng/ml (95% CI, -0.30 to 0.11; per-protocol: P = 0.02). Postoperative cardiac troponin I release was significantly less with xenon than with total intravenous anesthesia (intention-to-treat: P = 0.05; per-protocol: P = 0.02). Perioperative variables and postoperative outcomes were comparable across all groups, with no safety concerns. CONCLUSIONS: In postoperative cardiac troponin I release, xenon was noninferior to sevoflurane in low-risk, on-pump coronary artery bypass graft surgery patients. Only with xenon was cardiac troponin I release less than with total intravenous anesthesia. Xenon anesthesia appeared safe and feasible