373 research outputs found
A TARGETED LOAD-CARRIAGE TRAINING PROGRAM ELICITS POSITIVE ADAPTATIONS AFTER 10-WEEKS
The purpose of this study was to identify and characterise physical performance responses to a targeted 10-week load-carriage physical training intervention in males. Performance measures of maximal strength, heart rate, rating of perceived exertion, and basic fitness from nine male civilians before and after the 10-week training intervention are presented. There were significant increases in maximal force (~200 N) and aerobic performance (Level. Shuttle 8.9 vs 9,4 variables). Small-to-large effect sizes were shown for basic fitness and perceptual responses. The 10-week load-carriage physical training intervention elicited physical performance improvements and may facilitate load-carriage task performance
The antimicrobial activity of a carbon monoxide releasing molecule (EBOR-CORM-1) is shaped by intraspecific variation within3 Pseudomonas aeruginosa populations
Carbon monoxide releasing molecules (CORMs) have been suggested as a new synthetic class of antimicrobials to treat bacterial infections. Here we utilized a novel EBOR-CORM-1 ([NEt4][MnBr2(CO)4]) capable of water-triggered CO-release, and tested its efficacy against a collection of clinical Pseudomonas aeruginosa strains that differ in infection-related virulence traits. We found that while EBOR-CORM-1 was effective in clearing planktonic and biofilm cells of P. aeruginosa strain PAO1 in a concentration dependent manner, this effect was less clear and varied considerably between different P. aeruginosa cystic fibrosis (CF) lung isolates. While a reduction in cell growth was observed after 8 h of CORM application, either no effect or even a slight increase in cell densities and the amount of biofilm was observed after 24 h. This variation could be partly explained by differences in bacterial virulence traits: while CF isolates showed attenuated in vivo virulence and growth compared to strain PAO1, they formed much more biofilm, which could have potentially protected them from the CORM. Even though no clear therapeutic benefits against a subset of isolates was observed in an in vivo wax moth acute infection model, EBOR-CORM-1 was more efficient at reducing the growth of CF isolate co-culture populations harboring intraspecific variation, in comparison with efficacy against more uniform single isolate culture populations. Together these results suggest that CORMs could be effective at controlling genetically diverse P. aeruginosa populations typical for natural chronic CF infections and that the potential benefits of some antibiotics might not be observed if tested only against clonal bacterial populations
IMPROVEMENTS IN LOWER-LIMB STRENGTH ARE ASSOCIATED WITH HIP CONTROL DURING LOAD CARRIAGE IN FEMALES
The purpose of this study was to investigate the effect of lower-limb strength on lower-limb biomechanical responses over the duration of a load carriage march. Female civilians (n=12) completed a 5 km march at 5.5 km¡h-1 wearing a 23 kg external load before and after 10 weeks of hip-focussed training. Lower-limb 3D kinematics were acquired during the march, with lower-limb strength measures assessed prior to pre- and post-training marching tasks. Significant increases in lower-limb strength were elicited after training, alongside moderate to strong negative correlations between strength and hip adduction (
Prostate cancer risk: associations with ultraviolet radiation, tyrosinase and melanocortin-1 receptor genotypes
Exposure to ultraviolet radiation may reduce prostate cancer risk, suggesting that polymorphism in genes that mediate host pigmentation will be associated with susceptibility to this cancer. We studied 210 prostate cancer cases and 155 controls to determine whether vitamin D receptor (VDR, Taql and Fokl variants), tyrosinase (TYR, codon 192 variant) and melanocortin-1 receptor (MC1R, Arg151Cys, Arg160Trp, Val92Met, Asp294His and Asp84Glu variants) genotypes are associated with risk. UV exposure was determined using a questionnaire. MC1R Arg160/Arg160 homozygotes were at increased risk (P = 0.027, odds ratio = 1.94) while TYR A2/A2 homozygotes were at reduced risk of prostate cancer (P = 0.033, odds ratio = 0.48). These associations remained significant after correction for UV-exposure. Stratification of cases and controls by quartiles of exposure, showed that the protective effect of TYR A1A2 (P = 0.006, odds ratio 0.075) and A2A2 (P = 0.003, odds ratio 0.055) was particularly strong in subjects who had received the greatest exposure. Our data show for the first time, that allelism in genes linked with skin pigment synthesis is associated with prostate cancer risk possibly because it mediates the protective effects of UV. Importantly, susceptibility is associated with an interaction between host predisposition and exposure. Š 2001 Cancer Research Campaignââhttp://www.bjcancer.co
An EMG-Assisted Muscle-Force Driven Finite Element Analysis Pipeline to Investigate Joint- and Tissue-Level Mechanical Responses in Functional Activities : Towards a Rapid Assessment Toolbox
Publisher Copyright: Š 1964-2012 IEEE.Joint tissue mechanics (e.g., stress and strain) are believed to have a major involvement in the onset and progression of musculoskeletal disorders, e.g., knee osteoarthritis (KOA). Accordingly, considerable efforts have been made to develop musculoskeletal finite element (MS-FE) models to estimate highly detailed tissue mechanics that predict cartilage degeneration. However, creating such models is time-consuming and requires advanced expertise. This limits these complex, yet promising, MS-FE models to research applications with few participants and makes the models impractical for clinical assessments. Also, these previously developed MS-FE models have not been used to assess activities other than gait. This study introduces and verifies a semi-automated rapid state-of-the-art MS-FE modeling and simulation toolbox incorporating an electromyography- (EMG) assisted MS model and a muscle-force driven FE model of the knee with fibril-reinforced poro(visco)elastic cartilages and menisci. To showcase the usability of the pipeline, we estimated joint- and tissue-level knee mechanics in 15 KOA individuals performing different daily activities. The pipeline was verified by comparing the estimated muscle activations and joint mechanics to existing experimental data. To determine the importance of the EMG-assisted MS analysis approach, results were compared to those from the same FE models but driven by static-optimization-based MS models. The EMG-assisted MS-FE pipeline bore a closer resemblance to experiments compared to the static-optimization-based MS-FE pipeline. Importantly, the developed pipeline showed great potential as a rapid MS-FE analysis toolbox to investigate multiscale knee mechanics during different activities of individuals with KOA.Peer reviewe
Additively manufactured polyethylene terephthalate scaffolds for Scapholunate Interosseous Ligament Reconstruction
The regeneration of the ruptured scapholunate interosseous ligament (SLIL)
represents a clinical challenge. Here, we propose the use of a
Bone-Ligament-Bone (BLB) 3D-printed polyethylene terephthalate (PET) scaffold
for achieving mechanical stabilisation of the scaphoid and lunate following
SLIL rupture. The BLB scaffold featured two bone compartments bridged by
aligned fibres (ligament compartment) mimicking the architecture of the native
tissue. The scaffold presented tensile stiffness in the range of 260+/-38 N/mm
and ultimate load of 113+/-13 N, which would support physiological loading. A
finite element analysis, using inverse finite element analysis for material
property identification, showed an adequate fit between simulation and
experimental data. The scaffold was then biofunctionalized using two different
methods: injected with a Gelatin Methacryloyl solution containing human
mesenchymal stem cell spheroids or seeded with tendon-derived stem cells and
placed in a bioreactor to undergo cyclic deformation. The first approach
demonstrated high cell viability, as cells migrated out of the spheroid and
colonised the interstitial space of the scaffold. These cells adopted an
elongated morphology suggesting the internal architecture of the scaffold
exerted topographical guidance. The second method demonstrated the high
resilience of the scaffold to cyclic deformation and the secretion of a
fibroblastic related protein was enhanced by the mechanical stimulation. This
process promoted the expression of relevant proteins, such as Tenomodulin,
indicating mechanical stimulation may enhance cell differentiation and be
useful prior to surgical implantation. In conclusion, the PET scaffold
presented several promising characteristics for the immediate mechanical
stabilisation of disassociated scaphoid and lunate and, in the longer-term, the
regeneration of the ruptured SLIL
Serum 25-hydroxyvitamin D and cognitive decline in the very old: the Newcastle 85+ Study.
This is the final version of the article. Available from Wiley via the DOI in this record.BACKGROUND AND PURPOSE: Studies investigating the association between 25-hydroxyvitamin D [25(OH)D] and cognition in the very old (85+) are lacking. METHODS: Cross-sectional (baseline) and prospective data (up to 3 years follow-up) from 775 participants in the Newcastle 85+ Study were analysed for global (measured by the Standardized Mini-Mental State Examination) and attention-specific (measured by the attention battery of the Cognitive Drug Research test) cognitive performance in relation to season-specific 25(OH)D quartiles. RESULTS: Those in the lowest and highest season-specific 25(OH)D quartiles had an increased risk of impaired prevalent (1.66, 95% confidence interval 1.06-2.60, P = 0.03; 1.62, 95% confidence interval 1.02-2.59, P = 0.04, respectively) but not incident global cognitive functioning or decline in functioning compared with those in the middle quartiles adjusted for sociodemographic, health and lifestyle confounders. Random effects models showed that participants belonging to the lowest and highest 25(OH)D quartiles, compared with those in the middle quartiles, had overall slower (log-transformed) attention reaction times for Choice Reaction Time (lowest, β = 0.023, P = 0.01; highest, β = 0.021, P = 0.02), Digit Vigilance Task (lowest, β = 0.009, P = 0.05; highest, β = 0.01, P = 0.02) and Power of Attention (lowest, β = 0.017, P = 0.02; highest, β = 0.022, P = 0.002) and greater Reaction Time Variability (lowest, β = 0.021, P = 0.02; highest, β = 0.02, P = 0.03). The increased risk of worse global cognition and attention amongst those in the highest quartile was not observed in non-users of vitamin D supplements/medication. CONCLUSION: Low and high season-specific 25(OH)D quartiles were associated with prevalent cognitive impairment and poorer overall performance in attention-specific tasks over 3 years in the very old, but not with global cognitive decline or incident impairment.This work was supported by the National Institute for Health Research Newcastle Biomedical Research Centre based at Newcastle Hospitals Foundation Trust and Newcastle University (AG). The Newcastle 85+ Study has been funded by the Medical Research Council, Biotechnology and Biological Sciences Research Council and the Dunhill Medical Trust. Additional work has also been funded by the British Heart Foundation, Unilever Corporate Research, Newcastle University and National Health Service (NHS) North of Tyne (Newcastle Primary Care Trust). The views expressed in this paper are those of the authors and not necessarily those of the National Health Service, UK. We acknowledge the operational support of NHS North of Tyne, the local general practitioners and their staff, the research nurses, laboratory technicians, data management and clerical team, as well as many colleagues for their expert advice. Thanks are due especially to the study participants
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