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© 2020 The Author(s) Background & aims: This post hoc study aimed to determine whether major elective abdominal surgery had any acute impact on mitochondrial pyruvate dehydrogenase complex (PDC) activity and maximal mitochondrial ATP production rates (MAPR) in a large muscle group (vastus lateralis -VL) distant to the site of surgical trauma. Methods: Fifteen patients undergoing major elective open abdominal surgery were studied. Muscle biopsies were obtained after the induction of anesthesia from the VL immediately before and after surgery for the determination of PDC and maximal MAPR (utilizing a variety of energy substrates). Results: Muscle PDC activity was reduced by >50% at the end of surgery compared with pre-surgery (p < 0.05). Muscle MAPR were comprehensively suppressed by surgery for the substrate combinations: glutamate + succinate; glutamate + malate; palmitoylcarnitine + malate; and pyruvate + malate (all p < 0.05), and could not be explained by a lower mitochondrial yield. Conclusions: PDC activity and mitochondrial ATP production capacity were acutely impaired in muscle distant to the site of surgical trauma. In keeping with the limited data available, we surmise these events resulted from the general anesthesia procedures employed and the surgery related trauma. These findings further the understanding of the acute dysregulation of mitochondrial function in muscle distant to the site of major surgical trauma in patients, and point to the combination of general anesthesia and trauma related inflammation as being drivers of muscle metabolic insult that warrants further investigation. Clinical trial registration: Registered at (NCT01134809).

Summary Age-related sarcopenia and dynapenia are associated with frailty and metabolic diseases. Resistance exercise training (RET) adjuvant to evidence-based nutritional intervention(s) have been shown as mitigating strategies. Given that β-hydroxy-β-methyl-butyrate (HMB) supplementation during RET improves lean body mass in younger humans, and that we have shown that HMB acutely stimulates muscle protein synthesis (MPS) and inhibits breakdown; we hypothesized that chronic supplementation of HMB free acid (HMB-FA) would enhance MPS and muscle mass/function in response to RET in older people. We recruited 16 healthy older men (Placebo (PLA): 68.5 ± 1.0 y, HMB-FA: 67.8 ± 1.15 y) for a randomised double-blind-placebo controlled trial (HMB-FA 3 × 1 g/day vs. PLA) involving a 6-week unilateral progressive RET regime (6 × 8 repetitions, 75% 1-RM, 3 · wk−1). Deuterium oxide (D2O) dosing was performed over the first two weeks (0–2 wk) and last two weeks (4–6 wk) with bilateral vastus lateralis (VL) biopsies at 0–2 and 4–6 wk (each time 75 ± 2 min after a single bout of resistance exercise (RE)) for quantification of early and later MPS responses and post-RE myogenic gene expression. Thigh lean mass (TLM) was measured by DXA, VL thickness and architecture (fibre length and pennation angle) by ultrasound at 0/3/6 wk, and strength by knee extensor 1-RM testing and MVC by isokinetic dynamometry (approx. every 10 days). RET induced strength increases (1-RM) in the exercised leg of both groups (398 ± 22N to 499 ± 30N HMB-FA vs. 396 ± 29N to 510 ± 43N PLA (both P

Summary Background & aims Nutritional composition is key for skeletal muscle maintenance into older age. Yet the acute effects of collagen protein blended with other protein sources, in relation to skeletal muscle anabolism, are ill-defined. We investigated human muscle protein synthesis (MPS) responses to a 20 g blend of collagen protein hydrolysate + milk protein (CP+MP, 125 ml) oral nutritional supplement (ONS) vs. 20 g non-blended milk protein source (MP, 200 ml) ONS, in older adults. Methods Healthy older men (N = 8, 71±1 y, BMI: 27±1 kg·m−2) underwent a randomized trial of 20 g protein, from either a CP+MP blend (Fresubin®3.2 kcal DRINK), or a kcal-matched (higher in essential amino acids (EAA) ONS of MP alone. Vastus lateralis (VL) MPS and plasma AA were determined using stable isotope-tracer mass spectrometry; anabolic signaling was quantified via immuno-blotting in VL biopsies taken at baseline and 2/4 h after ONS feeding. Plasma insulin was measured via enzyme-linked immunosorbent assay (ELISA). Measures were taken at rest, after the feed (FED) and after the feed + exercise (FED-EX) conditions (unilateral leg exercise, 6 × 8, 75% 1-RM). Results MP resulted in a greater increase in plasma leucine (MP mean: 152 ± 6 μM, CP+MP mean: 113 ± 4 μM (Feed P

Summary Background & aims Postoperative hyperglycaemia is common in patients having major surgery and is associated with adverse outcomes. This study aimed to determine whether bacteraemia contributed to postoperative systemic inflammation, and whether increases in the expression of muscle mRNAs and proteins reflecting increased muscle inflammation, atrophy and impaired carbohydrate oxidation were evident at the time of surgery, and both local and distant to the site of trauma, and could be associated with impaired glucoregulation. Methods Fifteen adult patients without diabetes undergoing major abdominal surgery participated in this observational study set in a university teaching hospital. Arterialised-venous blood samples and muscle biopsies were obtained before and after major elective abdominal surgery, from sites local (rectus abdominis – RA) and remote to the site of surgery (vastus lateralis – VL). The main outcome measures included blood glucose concentrations, gut permeability and changes in expression of muscle mRNAs and proteins linked to inflammation and glucose regulation. Results Immediately postoperatively, RA demonstrated markedly increased mRNA expression levels of cathepsin-L (7.5-fold, P

Objective To evaluate learning results of critical care physiotherapists participating in a muscle ultrasound (MUS) educational program. Design Cross-sectional study. Setting A custom-made 20-hour MUS course was performed over a 2-week time period, including knobs familiarization, patient positioning, anatomic landmarks, image acquisition, and limb muscle measurements. Participants Nineteen critical care physiotherapists with little to no prior experience in ultrasound (N=19). Interventions Not applicable. Main Outcome Measures Theoretical knowledge, hands-on skills acquisition, and satisfaction were assessed. Inter- and intrarater reliability on landmarks, thickness, and pennation angle of quadriceps between participants was evaluated using intraclass correlation coefficients (ICCs). Reliability among instructors measured prior to the course was also reported as a reference. Results The percentage score (mean±SD) of knowledge questionnaires was 69±11 (pre-course), 89±10 (post-course), and 92±9 (hands-on skills). Course satisfaction scores ranged from 90%-100%. Pooled interrater reliability of participants (median ICC [interquartile range]) was good (0.70 [0.59-0.79]) for thickness, moderate (0.47 [0.46-0.92]) for landmarks, and absent (0.00 [0.00-0.05]) for pennation angle and the intrarater reliability was good (0.76 [0.51-0.91]) for thickness and weak (0.35 [0.29-0.52]) for pennation angle. Interrater ICC values for instructors were excellent (0.90) for thickness, good (0.67) for landmarks, and moderate (0.41) for pennation angle and intrarater ICC values were excellent (0.94) for thickness and good (0.75) for pennation angle. Conclusions Although our sample was quite small and homogeneous, increased theoretical knowledge, high hands-on performance acquisition, and good satisfaction of physiotherapists were observed. Reliability was moderate to excellent for thickness and landmarks and absent to weak for pennation angle. Landmarking and pennation angle remain challenges for physiotherapist training in the application of MUS. Further studies are needed to identify variables that could modify reliability during MUS training.

Highlights ► We investigated the relationship between walking impairment after stroke and integrity of the corticospinal tract (CST). ► We used transcranial magnetic stimulation and diffusion tensor imaging to assess CST integrity. ► We demonstrate that patients with more ipsilateral connectivity between the unlesioned M1 and the affected leg had more structural damage to their CST., Objective Studies on upper limb recovery following stroke have highlighted the importance of the structural and functional integrity of the corticospinal tract (CST) in determining clinical outcomes. However, such relationships have not been fully explored for the lower limb. We aimed to test whether variation in walking impairment was associated with variation in the structural or functional integrity of the CST. Methods Transcranial magnetic stimulation was used to stimulate each motor cortex while EMG recordings were taken from the vastus lateralis (VL) bilaterally; these EMG measures were used to calculate both ipsilateral and contralateral recruitment curves for each lower limb. The slope of these recruitment curves was used to examine the strength of functional connectivity from the motor cortex in each hemisphere to the lower limbs in chronic stroke patients and to calculate a ratio between ipsilateral and contralateral outputs referred to as the functional connectivity ratio (FCR). The structural integrity of the CST was assessed using diffusion tensor MRI to measure the asymmetry in fractional anisotropy (FA) of the internal capsule. Lower limb impairment and walking speed were also measured. Results The FCR for the paretic leg correlated with walking impairment, such that greater relative ipsilateral connectivity was associated with slower walking speeds. Asymmetrical FA values, reflecting reduced structural integrity of the lesioned CST, were associated with greater walking impairment. FCR and FA asymmetry were strongly positively correlated with each other. Conclusions Patients with relatively greater ipsilateral connectivity between the contralesional motor cortex and the paretic lower limb were more behaviorally impaired and had more structural damage to their ipsilesional hemisphere CST. Significance Measures of structural and functional damage may be useful in the selection of therapeutic strategies, allowing for more tailored and potentially more beneficial treatments.