Publications by authors named "Stephen D R Harridge"

As new space missions are being prepared, now is the time for accessible designs and approaches. In a workshop, we asked attendees to discuss the adjustments for people with disabilities in relation to the established barriers to human spaceflight. Potential challenges were grouped into medical, physiological, subsistence, and technical.

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This review arises from the symposium held in honour of Prof Jenny Morgan at UCL in 2024 and the authors would like to acknowledge the outstanding contribution that Prof Morgan has made to the field of translational muscle cell biology. Prof Morgan published a review article in 2010 entitled: Are human and mice satellite cells really the same? In which the authors highlighted differences between species which are still pertinent to skeletal muscle cell culture studies today. To our knowledge there are no comprehensive reviews which outline the considerable work that has been undertaken using human primary skeletal muscle origin cells as the main model system.

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Article Synopsis
  • Aging leads to physiological changes and increased disease vulnerability, culminating in higher mortality rates as individuals get older.
  • Regular physical activity (PA) and exercise can counteract aging effects, improve health span, and reduce the risk of chronic diseases such as heart disease and cancer.
  • Personalized exercise plans, including various forms of training like aerobic and resistance exercises, are essential for maintaining health and functionality in older adults, particularly those with age-related issues.
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Thymic involution is a key factor in human immune aging, leading to reduced thymic output and a decline in recent thymic emigrant (RTE) naive T cells in circulation. Currently, the precise definition of human RTEs and their corresponding cell surface markers lacks clarity. Analysis of single-cell RNA-seq/ATAC-seq data distinguished RTEs by the expression of SOX4, IKZF2, and TOX and CD38 protein, whereby surface CD38 expression universally identified CD8 and CD4 RTEs.

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Accessible spaceflight may seem a distant concept. As part of a diverse European Space Agency funded Topical Team, we are working on the physiological feasibility of space missions being undertaken by people with physical disabilities. Here, the first activity of this team is presented in the form of key lessons learned from aviation to inform new work on space missions.

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Changes in myonuclear architecture and positioning are associated with exercise adaptations and ageing. However, data on the positioning and number of myonuclei following exercise are inconsistent. Additionally, whether myonuclear domains (MNDs; i.

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Studies suggest that inducing gut microbiota changes may alter both muscle physiology and cognitive behaviour. Gut microbiota may play a role in both anabolic resistance of older muscle, and cognition. In this placebo controlled double blinded randomised controlled trial of 36 twin pairs (72 individuals), aged ≥60, each twin pair are block randomised to receive either placebo or prebiotic daily for 12 weeks.

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G tolerance has been widely assessed using Peripheral Light Loss (PLL), but this approach has several limitations and may lack sensitivity. The aim of this study was to investigate the use of a foveal visual endpoint for centrifuge research (Grating Loss; GL) and assess its repeatability, reliability, and usability with PLL as a reference. A total of 11 subjects undertook centrifuge assessment.

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Consistent blood biomarkers of hypobaric (altitude) decompression stress remain elusive. Recent laboratory investigation of decompression sickness risk at 25,000 ft (7620 m) enabled evaluation of early pathophysiological responses to exertional decompression stress. In this study, 15 healthy men, aged 20-50 yr, undertook 2 consecutive (same-day) ascents to 25,000 ft (7620 m) for 60 and 90 min, breathing 100% oxygen, each following 1 h of prior denitrogenation.

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Article Synopsis
  • The study found that military parachutist dispatchers face a high risk of severe decompression sickness (DCS) at 25,000 ft, especially with significant exertion.
  • During trials with 15 healthy men, cases of DCS, such as knee pain, occurred at higher altitudes, but less so at lower altitudes (22,000 ft).
  • The results suggest that repeat safe ascents to 22,000 ft are feasible with adequate ground-level air breaks, although older dispatchers with certain health conditions may still be at risk.
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Specific force (SF) has been shown to be reduced in some but not all studies of human aging using chemically skinned single muscle fibers. This may be due, in part, not only to the health status/physical activity levels of different older cohorts, but also from methodological differences in studying skinned fibers. The aim of the present study was to compare SF in fibers from older hip fracture patients (HFP), healthy master cyclists (MC), and healthy nontrained young adults (YA) using two different activating solutions.

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During voluntary muscle contractions, force output is characterized by constant inherent fluctuations, which can be quantified either according to their magnitude or temporal structure, that is, complexity. The presence of such fluctuations when targeting a set force indicates that control of force is not perfectly accurate, which can have significant implications for task performance. Compared to young adults, older adults demonstrate a greater magnitude and lower complexity in force fluctuations, indicative of decreased steadiness, and adaptability of force output, respectively.

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As the inherent ageing process affects every facet of biology, physiology could be considered as the study of the healthy human ageing process. Where biological health is affected by lifestyle, the continual and continuing interaction of this process with physical activity and other lifestyle choices determine whether the ageing trajectory is toward health or disease. The presentation of both these states is further modified in individuals by the interaction of inherent physiological heterogeneity and the heterogeneity associated with responses and adaptions to exercise.

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Chemically skinned fibres allow the study of human muscle contractile function in vitro. A particularly important parameter is specific force (SF), that is, maximal isometric force divided by cross-sectional area, representing contractile quality. Although SF varies substantially between studies, the magnitude and cause of this variability remains puzzling.

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Flight-related neck pain (FRNP) is a frequently reported musculoskeletal complaint among military helicopter aircrew. However, despite its prevalence and suspected causes, little is known of the underpinning pain mechanisms or the impact of neck pain on aircrews in-flight task performance. The biopsychosocial (BPS) approach to health, combined with the contemporary conceptualization of musculoskeletal pain, in which injury and pain are not necessarily synonymous, provides a relatively new holistic framework within which to consider the problem of FRNP in military helicopter aircrew.

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Article Synopsis
  • Data analysis is crucial in biology and medicine due to complex biological datasets, but programming and algorithm knowledge often limits researchers' capabilities.
  • SIMON is a modular, open-source software designed to apply over 180 advanced machine-learning algorithms to biomedical data easily.
  • With its user-friendly interface and automated processes, SIMON enables both technical and non-technical researchers to uncover important patterns in biomedical research.
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  • * Older male master cyclists (OT) showed higher gene and protein expression for important mitochondrial components compared to younger (YG) and older inactive (OG) males.
  • * The findings indicate that regular exercise can help preserve and even enhance mitochondrial function in older adults, challenging the idea that aging inevitably leads to decreased mitochondrial capacity.
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Type 2 Diabetes (T2D) is a major concern among Asian Indians, not least because many develop T2D at despite having a normal BMI (body mass index), and with relatively low body fat. Asian Indians are also generally considered to have relatively low skeletal muscle mass and strength, this has not been explored in the context of T2D. The present study aimed to compare skeletal muscle mass, function and contractile quality (strength/mass) between healthy controls, those with prediabetes (PD) as well as T2D middle-aged non-obese Asian Indians.

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  • Creatine dilution (D -cr) is a method used to estimate total skeletal muscle mass (SMM), but its application in athletes has not been extensively studied until now.
  • The study compared SMM estimates from D -cr and whole-body MRI in 20 national-level kayakers, revealing a strong correlation between the two methods but higher SMM estimates from D -cr.
  • Adjusting the assumed creatine pool size improved the agreement between D -cr and MRI, highlighting the need for careful consideration of creatine pool assumptions in athletic populations.
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