Mitochondrie, stress oxydant et protection musculaire

Controversy exists on which metabolites determine the exaggerated exercise pressor reflex (EPR) in peripheral artery disease (PAD). In decerebrated rats, we investigated the role played by lactate and hydrogen ions in a model of PAD, which was simulated by ligating the femoral artery for 72 h before the start of the experiment. Production of lactate and hydrogen ions by the contracting hindlimb muscles was manipulated by knocking out the myophosphorylase gene (pygm). In both knockout (pygm-/-; n = 13; 6-females) and wild-type rats (pygm+/+; n = 14; 7-females), the EPR was evoked by statically contracting the triceps-surae muscles. Blood pressure, tension, and renal sympathetic nerve activity were measured. Responsiveness of the metabolic component of the EPR was evaluated by intra-arterial injections of lactic acid and diprotonated phosphate solutions. Responsiveness of the mechanical component of the EPR was evaluated by stretching the calcaneal tendon. In each rat, the pressor responses evoked from the freely perfused triceps-surae muscles were compared to those evoked from the contralateral ischemic triceps-surae muscles. In pygm+/+ rats whose femoral artery was ligated, static contraction, lactic-acid injection and diprotonated phosphate injection evoked pressor responses that were 88%, 22%, and 58% greater than those evoked from muscles whose femoral arteries were freely perfused. In pygm-/- rats, ligation of the femoral artery for 72 h had no effect. In both groups, 72 h of femoral artery ligation exacerbated the pressor response to passive stretch. Lactate and hydrogen-ions accumulation in contracting myocytes plays a key role in exaggerating the metabolic component of the EPR evoked from hindlimb muscles with chronically-ligated femoral arteries.

Population aging leads to an increase in emergency hospitalizations among older adults, particularly those living in nursing homes (EHPAD). To help prevent such hospitalizations, the GER-e-TEC device was developed to provide home-based medical telemonitoring by collecting various physiological parameters. The aim of this study was to evaluate the user experience (UX) of the device among patients, caregivers, and healthcare professionals. The study included nine patients, nine healthcare professionals, and ten caregivers who had used GER-e-TEC for at least four weeks. UX was assessed using the AttrakDiff questionnaire, which measures both pragmatic and hedonic qualities of the device. The usability of the MyPredi application was evaluated with the DEEP questionnaire, while older adults' acceptance of technologies was assessed with the S-STAM scale. Descriptive statistical analyses and qualitative feedback were also used to complement the evaluation. The study revealed an overall positive UX. Patients and caregivers appreciated the user-friendliness and relevance of the device, although heterogeneous responses were observed. Healthcare professionals expressed concerns about usability, particularly the lack of clear guidance on procedures to follow in the event of an alert. The MyPredi application was generally well received, although some caregivers reported technical difficulties. GER-e-TEC was generally well accepted, especially by patients who found it reassuring. However, improvements are needed, particularly regarding the clarity of procedures and communication between healthcare professionals and the coordination unit. Despite these limitations, the device appears effective in improving home medical monitoring and preventing avoidable hospitalizations.

Abstract Over the last few decades, the agricultural industry has made significant advances in autonomous systems, such as wheeled robots, with the primary objective of improving efficiency while reducing the impact on the environment. In this context, determining a path for the robot that optimizes coverage while taking into account topography, robot characteristics, and operational requirements, is critical. In this paper, we present H‐CCPP, a novel hybrid method that combines the comprehensive coverage benefits of our previous approach O‐CCPP with the computational efficiency of the Fields2Cover algorithm. Besides optimizing coverage area, overlaps, and overall travel time, it significantly improves the computation process, and enhances the flexibility of trajectory generation. H‐CCPP also considers terrain inclination to address soil erosion and energy consumption. In an effort to support this innovative approach, we have also created and made available a public data set that includes both 2D and 3D representations of 30 agricultural fields. This resource not only allows us to illustrate the effectiveness of our approach but also provides invaluable data for future research in complete coverage path planning (CCPP) for modern agriculture.

We determined the role played by the transient receptor potential canonical 6 (TRPC6) channel in evoking the mechanical component of the exercise pressor reflex in male decerebrated Sprague–Dawley rats. TRPC6 channels were identified by quadruple‐labelled (DiI, TRPC6, neurofilament‐200 and peripherin) immunohistochemistry in dorsal root ganglion (DRG) cells innervating the triceps surae muscles (n = 12). The exercise pressor reflex was evoked by statically contracting the triceps surae muscles before and after injection of the TRPC6 antagonist BI‐749327 (n = 11; 12 μg kg−1) or SAR7334 (n = 11; 7 μg kg−1) or the TRPC6 positive modulator C20 (n = 11; 18 μg kg−1). Similar experiments were conducted while the muscles were passively stretched (n = 8–12), a manoeuvre that isolated the mechanical component of the reflex. Blood pressure, tension, renal sympathetic nerve activity (RSNA) and blood flow were recorded. Of the DRG cells innervating the triceps surae muscles, 85% stained positive for the TRPC6 antigen, and 45% of those cells co‐expressed neurofilament‐200. Both TRPC6 antagonists decreased the reflex pressor responses to static contraction (−32 to −42%; P < 0.05) and to passive stretch (−35 to −52%; P < 0.05), whereas C20 increased these responses (55–65%; P < 0.05). In addition, BI‐749327 decreased the peak and integrated RSNA responses to both static contraction (−39 to −43%; P < 0.05) and passive stretch (−56 to −62%; P < 0.05), whereas C20 increased the RSNA to passive stretch only. The onset latency of the decrease or increase in RSNA occurred within 2 s of the onset of the manoeuvres (P < 0.05). Collectively, our results show that TRPC6 plays a key role in evoking the mechanical component of the exercise pressor reflex.Key pointsThe exercise pressor reflex plays a key role in the sympathetic and haemodynamic responses to exercise. This reflex is composed of two components, namely the mechanoreflex and the metaboreflex.The receptors responsible for evoking the mechanoreflex are poorly documented. A good candidate for this function is the transient receptor potential canonical 6 (TRPC6) channel, which is activated by mechanical stimuli and expressed in dorsal root ganglia of rats.Using two TRPC6 antagonists and one positive modulator, we investigated the role played by TRPC6 in evoking the mechanoreflex in decerebrated rats.Blocking TRPC6 decreased the renal sympathetic and the pressor responses to both contraction and stretch, the latter being a manoeuvre that isolates the mechanoreflex. In contrast, the positive modulator increased the pressor reflex to contraction and stretch, in addition to the sympathetic response to stretch.Our results provide strong support for a role played by the TRPC6 channel in evoking the mechanoreflex.

Chronic kidney disease-associated pruritus (CKD-aP) is a disabling symptom which is frequent and often underestimated. Pa-MRC has a negative impact on quality of life, and is frequently accompanied by sleep disorders and depression. The approval of difelikefalin – a kappa opioid receptor agonist – in this indication requires updated recommendations. As a first step, secondary causes of pruritus without skin lesions must be ruled out, and general measures taken (emollients, psychological support, optimization of dialysis, normalization of serum calcium, phosphate and PTH in the range proposed by the KGIDO guidelines, treatment of iron deficiency). A therapeutic test with a non-sedating oral antihistamine may be proposed. If this test is negative, Pa-MRC must be strongly suspected, and its intensity (WI-NRS scale) and impact on quality of life assessed. In the case of mild Pa-MRC (WI-NRS ≤ 3), only general measures are implemented. If Pa-MRC is moderate to severe (WI-NRS ≥ 4), specific treatment with difelikefaline can be initiated for 6 months in addition to general measures. At 3 months, if the response is complete (WI-NRS score ≤ 1) or partial (decline ≥ 3 points), treatment is continued. At 6 months, if the response is complete, treatment may be discontinued with the patient’s agreement; treatment is maintained if the response is partial. At 3 or 6 months, if response is insufficient (decline < 3 points) and/or in the event of intolerance, treatment is discontinued and an alternative treatment (e.g., gabapentinoids, UVB) may be considered after dermatological consultation.

An ischemia-reperfusion injury (IRI) results from a prolonged ischemic insult followed by the restoration of blood perfusion, being a common cause of morbidity and mortality, especially in liver transplantation. At the maximum of the potential damage, IRI is characterized by 2 main phases. The first is the ischemic phase, where the hypoxia and vascular stasis induces cell damage and the accumulation of damage-associated molecular patterns and cytokines. The second is the reperfusion phase, where the local sterile inflammatory response driven by innate immunity leads to a massive cell death and impaired liver functionality. The ischemic time becomes crucial in patients with underlying pathophysiological conditions. It is possible to compare this process to a shooting gun, where the loading trigger is the ischemia period and the firing shot is the reperfusion phase. In this optic, this article aims at reviewing the main ischemic events following the phases of the surgical timeline, considering the consequent reperfusion damage.