Search

Several studies have proposed the cell membrane as the main water diffusion restricting factor in the skeletal muscle cell. We sought to establish whether a particular form of exercise training (which is likely to affect only intracellular components) could affect water diffusion. The purpose of this study is to characterise prospectively the changes in diffusion tensor imaging (DTI) eigenvalues of thigh muscle resulting from hybrid training (HYBT) in patients with non-alcoholic fatty liver disease (NAFLD). Twenty-one NAFLD patients underwent HYBT for 30 minutes per day, twice a week for 6 months. Patients were scanned using DTI of the thigh pre- and post-HYBT. Fractional anisotropy (FA), apparent diffusion coefficient (ADC), the three eigenvalues lambda 1 (λ1), λ2, λ3, and the maximal cross sectional area (CSA) were measured in bilateral thigh muscles: knee flexors (biceps femoris (BF), semitendinosus (ST), semimembranous (SM)) and knee extensors (medial vastus (MV), intermediate vastus (IV), lateral vastus (LV), and rectus femoris (RF)), and compared pre- and post-HYBT by paired t-test. Muscle strength of extensors ( P < 0.01), but not flexors, increased significantly post-HYBT. For FA, ADC and eigenvalues, the overall picture was of increase. Some ( P < 0.05 in λ2 and P < 0.01 in λ1) eigenvalues of flexors and all (λ1-λ3) eigenvalues of extensors increased significantly ( P < 0.01) post-HYBT. HYBT increased all 3 eigenvalues. We suggest this might be caused by enlargement of muscle intracellular space. [ABSTRACT FROM AUTHOR]

Background: Responsiveness and floor and ceiling effect are important parameters for evaluating the sensitivity of an outcome instrument in detecting the changes in the clinical condition of patients after an intervention as well as evaluating the content validity of the instrument. The aim of this prospective observational study was to assess these parameters for the Liverpool Elbow Score (LES) in total elbow replacement (TER). Methods: The study included 121 cemented TER cases with linked elbow prosthesis (Discovery Elbow, Biomet Orthopaedics, Swindon, UK) for various conditions, including inflammatory arthritis, noninflammatory arthritis, trauma, and loosening. The proportion of patients with the lowest score (0 points; floor effect) and maximum score (10 points; ceiling effect) was checked preoperatively and 1 year postoperatively. Distribution-based methods (effect size [ES], standardized response mean [SRM], Guyatt responsiveness ratio [GRR]) and anchor-based methods (receiver operating characteristic [ROC] curve and Spearman correlation coefficient) were used to assess responsiveness. Patient satisfaction after TER was used as an external anchor. Results: Patients were a mean age of 63 years (range, 20-86 years). Large ES (1.64), SRM (1.25), and GRR (1.69) were found during the follow-up period. Area under the ROC curve was 0.71 (95% confidence interval, 0.56-0.87; P = .03). There was significant positive correlation (Spearman correlation coefficient, 0.35; P = .004) between changes in LES and satisfaction level. LES showed no floor and ceiling effect preoperatively and at 1 year postoperatively. Conclusion: LES is a responsive measure and has no floor and ceiling effect. This encourages its use as an outcome instrument for TER. [ABSTRACT FROM AUTHOR]

Summary: The aim of the study was to determine whether 16 sessions of exercise training, completed twice weekly, alters exercise capacity, quadriceps muscle metabolism, cross-sectional area (CSA) and strength in subjects with chronic obstructive pulmonary disease (COPD). We studied (a) 10 COPD subjects (mean age±sem=71±2 years; FEV1=0.99±0.1L) before and after 16 sessions of exercise training, and (b) 10 healthy subjects (age=68±3 years). The COPD subjects underwent an incremental peak exercise test using a cycle ergometer and a 6-min walk test: both improved following exercise training (). Magnetic resonance spectroscopy measurements, in quadriceps muscle, of post-exercise phosphocreatinine (PCr) recovery kinetics were used to assess mitochondrial function in vivo: in the COPD subjects pre-training this was 19±8% lower than in healthy subjects (), but a 38±12% increase was seen in the COPD subjects following training (). Magnetic resonance imaging was used to assess quadriceps CSA: after training in the COPD subjects this showed a 7±2% increase (). Quadriceps strength, measured by the best of five maximum voluntary contractions, also showed a 32±11% increase in the COPD subjects (). Sixteen sessions of exercise training, performed twice weekly, increased exercise capacity as well as quadriceps mitochondrial capacity, CSA and strength in the subjects with COPD. [Copyright &y& Elsevier]

The aim of this study was to investigate the effects of gender and age in the population of patients attending hospital as a result of ‘underfoot’ accidents. Patients attending hospital for the diagnosis and treatment of injuries were interviewed using a portable computer-based questionnaire, the Merseyside Accident Information Model (MAIM). Two studies were used, based on 2516 (1555 men and 961 women) and 1306 (751 men and 575 women) patients, interviewed while attending A&E, orthopaedic wards and fracture clinics in a large teaching hospital. The age range of patients in both studies was 15–90 years. The philosophy underlying MAIM is to record all the available information about the immediate circumstances of the accident. This allows us to identify (1) sources of injuries and (2) incidence of injuries associated with these variables: age, gender and underfoot events (classified by slips, trips, missed footing, turned ankle, unintended step on and loss of balance as the first unexpected event). Even though the criteria for patient selection differed in the two studies, the analysis of both revealed similar characteristics. In both studies, logistic regression analysis showed underfoot accidents were predicted by (1) gender (odds ratios 1.85 and 2.83) and (2) age (odds ratios 1.30 and 1.22) per 10 year increase (all P<0.001). An increasing fraction of underfoot accidents (odds ratios 1.88 and 2.71) studied produce fractures as the age of the patient increases (odds ratios 1.12 and 1.21; all P<0.001). Patients suffering underfoot accidents are increasingly likely to be female as their age increases. This is true both for ‘fracture’ and ‘non-fracture’ accidents, and in the latter at least this cannot be due to osteoporosis. We conclude that older people are increasingly likely to suffer fractures in underfoot accidents. Women are more likely to have underfoot accidents, increasingly with advancing age, and this cannot be explained by gender and ageing effects associated with fractures. We believe these data are potentially important for cost-effective targeting of preventative measures. [Copyright &y& Elsevier]

Abstract: The most important function of mitochondria is the production of energy in the form of ATP. The socio-economic impact of human diseases that affect skeletal muscle mitochondrial function is growing, and improving their clinical management critically depends on the development of non-invasive assays to assess mitochondrial function and monitor the effects of interventions. 31P magnetic resonance spectroscopy provides two approaches that have been used to assess in vivo ATP synthesis in skeletal muscle: measuring Pi ⟶ATP exchange flux using saturation transfer in resting muscle, and measuring phosphocreatine recovery kinetics after exercise. However, Pi ⟶ATP exchange does not represent net mitochondrial ATP synthesis flux and has no simple relationship with mitochondrial function. Post-exercise phosphocreatine recovery kinetics, on the other hand, yield reliable measures of muscle mitochondrial capacity in vivo, whose ability to define the site of functional defects is enhanced by combination with other non-invasive techniques. [Copyright &y& Elsevier]

Abstract: Objectives: (a) To investigate changes in muscular strength, fatigue and activity in recovered tennis elbow (RTE); (b) to assess the appropriateness of EMG and strength measurements in monitoring functional recovery in tennis elbow (TE). Methods: Study included three age-matched female groups of Control (C) (n =8, no history of musculoskeletal problems), TE (n =7, local tenderness at the lateral epicondyle and pain with resisted wrist and middle finger extension) and RTE (n =6, asymptomatic for at least 6 months, no lateral epicondyle tenderness). Measurements included metacarpophalangeal (MCP), wrist, shoulder and grip isometric strength and EMG measures of muscle fatigue and activity for five forearm muscles (wrist extensors and flexors). Results: Strength was greater (p <0.05) for all measurements in C compared to RTE and TE except for MCP extension. Only MCP extension was stronger in RTE than TE. EMG revealed increased activity of extensor carpi radialis (ECR) in RTE, decreased in TE. Conclusions: Despite attenuation of pain, global upper limb weakness in RTE indicated incomplete functional recovery. Increased strength of MCP extension may protect weakened wrist extensors from further injury. Monitoring the ECR activity as well as strength measurements may provide a useful assessment of functional recovery in TE. [Copyright &y& Elsevier]

Objective Assessment of calcaneus microstructure using high-resolution peripheral quantitative computed tomography (HR-pQCT) might be used to improve fracture risk predictions or to assess responses to pharmacological and physical interventions. To develop a standard clinical protocol for the calcaneus, we validated calcaneus trabecular microstructure measured by HR-pQCT against ‘gold-standard’ micro-CT measurements. Methods Ten human cadaveric feet were scanned in situ using HR-pQCT (isotropic 82 μm voxel size) at 100, 150 and 200 ms integration times, and at 100 ms integration time following removal of the calcaneus from the foot ( ex vivo ). Dissected portions of these bones were scanned using micro-computed tomography (micro-CT) at an isotropic 17.4 μm voxel size. HR-pQCT images were rigidly registered to those obtained with micro-CT and divided into multiple 5 mm sided cubes to evaluate and compare morphometric parameters between the modalities. Standard HR-pQCT measurements (derived bone volume fraction (BV/TV d ); trabecular number, Tb.N; derived trabecular thickness, Tb.Th d ; derived trabecular spacing, Tb.Sp d ) and corresponding micro-CT voxel-based measurements (BV/TV, Tb.N, Tb.Th, Tb.Sp) were compared. Results A total of 108 regions of interest were analysed across the 10 specimens. At all integration times HR-pQCT BV/TV d was strongly correlated with micro-CT BV/TV (r 2 = 0.95–0.98, RMSE = 1%), but BV/TV d was systematically lower than that measured by micro-CT (mean bias = 5%). In contrast, HR-pQCT systematically overestimated Tb.N at all integration times; of the in situ scans, 200 ms yielded the lowest mean bias and the strongest correlation with micro-CT (r 2 = 0.61, RMSE = 0.15 mm −1 ). Regional analysis revealed greater accuracy for Tb.N in the superior regions of the calcaneus at all integration times in situ (mean bias = 0.44–0.85 mm −1 ; r 2 = 0.70–0.88, p < 0.001 versus mean bias = 0.63–1.46 mm −1 ; r 2 ≤ 0.08, p ≥ 0.21 for inferior regions). Tb.Sp d was underestimated by HR-pQCT compared to micro-CT, but showed similar trends with integration time and the region evaluated as Tb.N. HR-pQCT Tb.Th d was also underestimated and moderately correlated (r 2 = 0.53–0.59) with micro-CT Tb.Th, independently from the integration time. Stronger correlations, smaller biases and error were found in the scans of the calcaneus ex vivo compared to in situ . Conclusion Calcaneus trabecular BV/TV d and trabecular microstructure, particularly in the superior region of the calcaneus, can be assessed by HR-pQCT. The highest integration time examined, 200 ms, compared best with micro-CT. Weaker correlations for microstructure at inferior regions, and also with lower integration times, might limit the use of the proposed protocol, which warrants further investigation in vivo . [ABSTRACT FROM AUTHOR]

Neuroticism is one of the most robust higher-order personality traits associated with negative emotionality and risk of mental disorders. Many studies have investigated relationships between neuroticism and the brain, but the results have been inconsistent. We conducted a meta-analysis of whole-brain resting-state functional neuroimaging studies to identify the most stable neurofunctional substrates of neuroticism. We found stable significant positive correlations between neuroticism and resting-state brain activity in the left middle temporal gyrus (MTG), left striatum, and right hippocampus. In contrast, resting-state brain activity in the left superior temporal gyrus (STG) and right supramarginal gyrus (SMG) was negatively associated with neuroticism. Additionally, meta-regression analysis revealed brain regions in which sex and age moderated the link of spontaneous activity with neuroticism. This is the first study to provide a comprehensive understanding of resting-state brain activity correlates of neuroticism, and the findings may be useful for the targeting of specific brain regions for interventions to decrease the risks of mental health problems. • This is the first meta-analysis of resting-state functional neuroimaging studies exploring brain correlates of neuroticism. • We identified consistent and replicable functional brain activity alterations associated with neuroticism. • The findings may be useful for the selection of targeted brain regions for interventions on neuroticism. [ABSTRACT FROM AUTHOR]

Abstract: Background: Subjects with Fontan-type circulation have no sub-pulmonary ventricle and thus depend exquisitely on the respiratory bellows and peripheral muscle pump for cardiac filling. We hypothesised that resistance training to augment the peripheral muscle pump might improve cardiac filling, reduce inspiratory-dependence of IVC return to the heart and thus improve exercise capacity and cardiac output on constant positive airway pressure (CPAP). Methods: Eleven Fontan subjects (32+/−2years, mean+/−SEM) had cardiac magnetic resonance imaging (MRI) and exercise testing (CPET); six underwent 20weeks of high-intensity resistance training; others were non-exercising controls. After training, CPET was repeated. Four trainers had MRI with real-time flow measurement at rest, exercise and on CPAP in the trained state and following a 12-month detrain. Results: In the trained state, muscle strength increased by 43% (p=0.002), as did total muscle mass (by 1.94kg, p=0.003) and peak VO2 (by 183ml/min, p=0.02). After detraining, calf muscle mass and peak workload had fallen significantly (p<0.03 for both) as did peak VO2 (2.72 vs. 2.18l/min, p<0.001) and oxygen pulse, a surrogate for SV (16% lower, p=0.005). Furthermore after detraining, SV on MRI decreased at rest (by 11ml, p=0.01) and during moderate-intensity exercise (by 16ml, p=0.04); inspiratory-dependent IVC blood return during exercise was 40% higher (p=0.02). On CPAP, cardiac output was lower in the detrained state (101 vs. 77ml/s, p=0.03). Conclusions: Resistance muscle training improves muscle mass, strength and is associated with improved cardiac filling, stroke volume, exercise capacity and cardiac output on CPAP, in adults with Fontan-type circulation. [Copyright &y& Elsevier]

• The first vertex-based meta-analysis of whole-brain studies to investigate cortical thickness changes in patients with PTSD. • The superior temporal gyrus and right superior frontal gyrus may play an important role in the pathogenesis of PTSD. • Symptom severity correlates with cortical thickness in the left superior frontal gyrus. Neuroimaging studies report altered cortical thickness in patients with post-traumatic stress disorder (PTSD), but the results are inconsistent. Using anisotropic effect-size seed-based d mapping (AES-SDM) software with its recently-developed meta-analytic thickness mask, we conducted a meta-analysis of published studies which used whole-brain surface-based morphometry, in order to define consistent cortical thickness alterations in PTSD patients. Eleven studies with 438 patients and 396 controls were included. Compared with all controls, patients with PTSD showed increased cortical thickness in right superior temporal gyrus, and in left and right superior frontal gyrus; the former survived in subgroup analysis of adult patients, and in subgroup comparison with only non-PTSD trauma-exposed controls, the latter in subgroup comparison with only non-trauma-exposed healthy controls. Cortical thickness in right superior frontal gyrus was positively associated with percentage of female patients, and cortical thickness in left superior frontal gyrus was positively associated with symptom severity measured by the clinician-administered PTSD scale. These robust results may help to elucidate the pathophysiology of PTSD. [ABSTRACT FROM AUTHOR]