Sex disparities of human neuromuscular decline in older humans.

Females typically live longer than males but, paradoxically, spend a greater number of later years in poorer health. The neuromuscular system is a critical component of the progression to frailty, and motor unit (MU) characteristics differ by sex in healthy young individuals and may adapt to ageing in a sex-specific manner due to divergent hormonal profiles. The purpose of this study was to investigate sex differences in vastus lateralis (VL) MU structure and function in early to late elderly humans. Intramuscular electromyography signals from 50 healthy older adults (M/F: 26/24) were collected from VL during standardized submaximal contractions and decomposed to quantify MU characteristics. Muscle size and neuromuscular performance were also measured. Females had higher MU firing rate (FR) than males (P = 0.025), with no difference in MU structure or neuromuscular junction transmission (NMJ) instability. All MU characteristics increased from low- to mid-level contractions (P < 0.05) without sex × level interactions. Females had smaller cross-sectional area of VL, lower strength and poorer force steadiness (P < 0.05). From early to late elderly, both sexes showed decreased neuromuscular function (P < 0.05) without sex-specific patterns. Higher VL MUFRs at normalized contraction levels previously observed in young are also apparent in old individuals, with no sex-based difference of estimates of MU structure or NMJ transmission instability. From early to late elderly, the deterioration of neuromuscular function and MU characteristics did not differ between sexes, yet function was consistently greater in males. These parallel trajectories underscore the lower initial level for older females and may offer insights into identifying critical intervention periods. KEY POINTS: Females generally exhibit an extended lifespan when compared to males, yet this is accompanied by a poorer healthspan and higher rates of frailty. In healthy young people, motor unit firing rate (MUFR) at normalized contraction intensities is widely reported to be higher in females than in age-matched males. Here we show in 50 people that older females have higher MUFR than older males with little difference in other MU parameters. The trajectory of decline from early to late elderly does not differ between sexes, yet function is consistently lower in females. These findings highlight distinguishable sex disparities in some MU characteristics and neuromuscular function, and suggest early interventions are needed for females to prevent functional deterioration to reduce the ageing health-sex paradox.

Photoelectrochemical CO2 Reduction to CO Enabled by a Molecular Catalyst Attached to High-Surface-Area Porous Silicon.

A high-surface-area p-type porous Si photocathode containing a covalently immobilized molecular Re catalyst is highly selective for the photoelectrochemical conversion of CO2 to CO. It gives Faradaic efficiencies of up to 90% for CO at potentials of -1.7 V (versus ferrocenium/ferrocene) under 1 sun illumination in an acetonitrile solution containing phenol. The photovoltage is approximately 300 mV based on comparisons with similar n-type porous Si cathodes in the dark. Using an estimate of the equilibrium potential for CO2 reduction to CO under optimized reaction conditions, photoelectrolysis was performed at a small overpotential, and the onset of electrocatalysis in cyclic voltammograms occurred at a modest underpotential. The porous Si photoelectrode is more stable and selective for CO production than the photoelectrode generated by attaching the same Re catalyst to a planar Si wafer. Further, facile characterization of the porous Si-based photoelectrodes using transmission mode FTIR spectroscopy leads to highly reproducible catalytic performance.

Skeletal muscle dysfunction with advancing age.

As a result of advances in medical treatments and associated policy over the last century, life expectancy has risen substantially and continues to increase globally. However, the disconnect between lifespan and 'health span' (the length of time spent in a healthy, disease-free state) has also increased, with skeletal muscle being a substantial contributor to this. Biological ageing is accompanied by declines in both skeletal muscle mass and function, termed sarcopenia. The mechanisms underpinning sarcopenia are multifactorial and are known to include marked alterations in muscle protein turnover and adaptations to the neural input to muscle. However, to date, the relative contribution of each factor remains largely unexplored. Specifically, muscle protein synthetic responses to key anabolic stimuli are blunted with advancing age, whilst alterations to neural components, spanning from the motor cortex and motoneuron excitability to the neuromuscular junction, may explain the greater magnitude of function losses when compared with mass. The consequences of these losses can be devastating for individuals, their support networks, and healthcare services; with clear detrimental impacts on both clinical (e.g., mortality, frailty, and post-treatment complications) and societal (e.g., independence maintenance) outcomes. Whether declines in muscle quantity and quality are an inevitable component of ageing remains to be completely understood. Nevertheless, strategies to mitigate these declines are of vital importance to improve the health span of older adults. This review aims to provide an overview of the declines in skeletal muscle mass and function with advancing age, describes the wide-ranging implications of these declines, and finally suggests strategies to mitigate them, including the merits of emerging pharmaceutical agents.

Neurodiversity and disability: what is at stake?

Neurodiversity has come hugely to the fore in recent years in a variety of contexts, and is now subject to academic debate, activist discussion, and increasingly embedded in a range of institutional and corporate settings in the Global North, from workplaces to early years education, from psychotherapy to mainstream political discourses. The term has gained traction in Medical Humanities, as well as debate within bioethics, philosophy of psychology, and of law. Institutionally, it is now relied on in therapeutic practice, autism service provision, as well as in higher education, in particular. In this conceptual article we examine what is at stake in these usages and the implications in need of scrutiny. We resituate neurodiversity in relation to questions of disability by examining the deployment of neurology as the basis for identity, rights and benefits. The emergence of the term and the understandings to which it gives rise, we argue, leave out urgent questions of what is at stake for disabled people in a political climate of increasing harshness and ableism.

Contrast-enhanced ultrasound repeatability for the measurement of skeletal muscle microvascular blood flow.

NEW FINDINGS: What is the central question of this study? Contrast-enhanced ultrasound (CEUS) can be used to directly assess skeletal muscle perfusion but its day-to-day repeatability over time has not yet been validated: is CEUS a repeatable method for the measurement of skeletal muscle microvascular blood flow (MBF) at rest and in response to exercise, across independent assessment sessions? What is the main finding and its importance? A strong agreement between CEUS MBF measures across sessions suggests it is a repeatable method for assessing skeletal muscle perfusion over time. This validation provides confidence for incorporating these measures into longitudinal studies such as a chronic intervention or disease progression to gain further knowledge of skeletal muscle microvascular function. ABSTRACT: Contrast-enhanced ultrasound (CEUS) can be used to directly assess skeletal muscle perfusion. However, its repeatability over time has not yet been validated and therefore its use in longitudinal measures (i.e., exploring the impact of a chronic intervention or disease progression) is limited. This study aimed to determine the repeatability of CEUS for the measurement of skeletal muscle microvascular blood flow (MBF) at baseline and in response to exercise, across independent assessment sessions. Ten healthy volunteers (five female; 30 ± 6 years) had CEUS of the right vastus lateralis recorded in two separate sessions, 14 days apart. Measurements were taken at baseline, during an isometric leg extension and during recovery. Acoustic intensity data from a region of interest were plotted as a replenishment curve to obtain blood volume (A) and flow velocity (ß) values from a one-phase association non-linear regression of mean tissue echogenicity. Linear regression and Bland-Altman analyses of A and ß values were performed, with significance assumed as P < 0.05. Strong positive correlations were observed across sessions for all A and ß values (both P < 0.0001). Bland-Altman analysis showed a bias (SD) of -0.013 ± 1.24 for A and -0.014 ± 0.31 for ß. A bias of 0.201 ± 0.770 at baseline, 0.527 ± 1.29 during contraction and -0.203 ± 1.29 at recovery was observed for A, and -0.0328 ± 0.0853 (baseline), -0.0446 ± 0.206 (contraction) and 0.0382 ± 0.233 (recovery) for ß. A strong agreement between CEUS MBF measures across independent sessions suggests it to be a repeatable method for assessing skeletal muscle perfusion over time, and therefore facilitates wider use in longitudinal studies.

Acute adaptation of central and peripheral motor unit features to exercise-induced fatigue differs with concentric and eccentric loading.

NEW FINDINGS: What is the central question of this study? Conflicting evidence exists on motor unit (MU) firing rate in response to exercise-induced fatigue, possibly due to the contraction modality used: Do MU properties adapt similarly following concentric and eccentric loading? What is the main finding and its importance? MU firing rate increased following eccentric loading only despite a decline in absolute force. Force steadiness deteriorated following both loading methods. Central and peripheral MU features are altered in a contraction type-dependant manner, which is an important consideration for training interventions. ABSTRACT: Force output of muscle is partly mediated by the adjustment of motor unit (MU) firing rate (FR). Disparities in MU features in response to fatigue may be influenced by contraction type, as concentric (CON) and eccentric (ECC) contractions demand variable amounts of neural input, which alters the response to fatigue. This study aimed to determine the effects of fatigue following CON and ECC loading on MU features of the vastus lateralis (VL). High-density surface (HD-sEMG) and intramuscular (iEMG) electromyography were used to record MU potentials (MUPs) from bilateral VLs of 12 young volunteers (six females) during sustained isometric contractions at 25% and 40% of the maximum voluntary contraction (MVC), before and after completing CON and ECC weighted stepping exercise. Multi-level mixed effects linear regression models were performed with significance assumed as P < 0.05. MVC decreased in both CON and ECC legs post-exercise (P < 0.0001), as did force steadiness at both 25% and 40% MVC (P < 0.004). MU FR increased in ECC at both contraction levels (P < 0.001) but did not change in CON. FR variability increased in both legs at 25% and 40% MVC following fatigue (P < 0.01). From iEMG measures at 25% MVC, MUP shape did not change (P > 0.1) but neuromuscular junction transmission instability increased in both legs (P < 0.04), and markers of fibre membrane excitability increased following CON only (P = 0.018). These data demonstrate that central and peripheral MU features are altered following exercise-induced fatigue and differ according to exercise modality. This is important when considering interventional strategies targeting MU function.

Ageing and exercise-induced motor unit remodelling.

A motor unit (MU) comprises the neuron cell body, its corresponding axon and each of the muscle fibres it innervates. Many studies highlight age-related reductions in the number of MUs, yet the ability of a MU to undergo remodelling and to expand to rescue denervated muscle fibres is also a defining feature of MU plasticity. Remodelling of MUs involves two coordinated processes: (i) axonal sprouting and new branching growth from adjacent surviving neurons, and (ii) the formation of key structures around the neuromuscular junction to resume muscle-nerve communication. These processes rely on neurotrophins and coordinated signalling in muscle-nerve interactions. To date, several neurotrophins have attracted focus in animal models, including brain-derived neurotrophic factor and insulin-like growth factors I and II. Exercise in older age has demonstrated benefits in multiple physiological systems including skeletal muscle, yet evidence suggests this may also extend to peripheral MU remodelling. There is, however, a lack of research in humans due to methodological limitations which are easily surmountable in animal models. To improve mechanistic insight of the effects of exercise on MU remodelling with advancing age, future research should focus on combining methodological approaches to explore the in vivo physiological function of the MU alongside alterations of the localised molecular environment.

Training-induced improvements in knee extensor force accuracy are associated with reduced vastus lateralis motor unit firing variability.

NEW FINDINGS: What is the central question of this study? Can bilateral knee extensor force accuracy be improved following 4 weeks of unilateral force accuracy training and are there any subsequent alterations to central and/or peripheral motor unit features? What is the main finding and its importance? In the trained limb only, knee extensor force tracking accuracy improved with reduced motor unit firing rate variability in the vastus lateralis, and there was no change to neuromuscular junction transmission instability. Interventional strategies to improve force accuracy may be directed to older/clinical populations where such improvements may aid performance of daily living activities. ABSTRACT: Muscle force output during sustained submaximal isometric contractions fluctuates around an average value and is partly influenced by variation in motor unit (MU) firing rates. MU firing rate (FR) variability seemingly reduces following exercise training interventions; however, much less is known with respect to peripheral MU properties. We therefore investigated whether targeted force accuracy training could lead to improved muscle functional capacity and control, in addition to determining any alterations of individual MU features. Ten healthy participants (seven females, three males, 27 ± 6 years, 170 ± 8 cm, 69 ± 16 kg) underwent a 4-week supervised, unilateral knee extensor force accuracy training intervention. The coefficient of variation for force (FORCECoV ) and sinusoidal wave force tracking accuracy (FORCESinu ) were determined at 25% maximal voluntary contraction (MVC) pre- and post-training. Intramuscular electromyography was utilised to record individual MU potentials from the vastus lateralis (VL) muscles at 25% MVC during sustained contractions, pre- and post-training. Knee extensor muscle strength remained unchanged following training, with no improvements in unilateral leg-balance. FORCECoV and FORCESinu significantly improved in only the trained knee extensors by ∼13% (P = 0.01) and ∼30% (P < 0.0001), respectively. MU FR variability significantly reduced in the trained VL by ∼16% (n = 8; P = 0.001), with no further alterations to MU FR or neuromuscular junction transmission instability. Our results suggest muscle force control and tracking accuracy is a trainable characteristic in the knee extensors, which is likely explained by the reduction in MU FR variability which was apparent in the trained limb only.

FARGO-360: a multi-disciplinary survey of practice and perspectives on provision of care for patients with frailty presenting with gynecological cancers in the UK and Ireland.

OBJECTIVES: Frailty has been associated with worse cancer-related outcomes for people with gynecological cancers. However, the lack of clear guidance on how to assess and modify frailty prior to instigating active treatments has the potential to lead to large variations in practice and outcomes. This study aimed to evaluate current practice and perspectives of healthcare practitioners on the provision of care for patients with frailty and a gynecological cancer. METHODS: Data were collected via a questionnaire-based survey distributed by the Audit and Research in Gynecological Oncology (ARGO) collaborative to healthcare professionals who identified as working with patients with gynecological malignancies in the United Kingdom (UK) or Ireland. Study data were collected using REDCap software hosted at the University of Manchester. Responses were collected over a 16 week period between January and April 2021. RESULTS: A total of 206 healthcare professionals (30 anesthetists (14.6%), 30 pre-operative nurses (14.6%), 51 surgeons (24.8%), 34 cancer specialist nurses (16.5%), 21 medical/clinical oncologists (10.2%), 25 physiotherapists/occupational therapists (12.1%) and 15 dieticians (7.3%)) completed the survey. The respondents worked at 19 hospital trusts across the UK and Ireland. Frailty scoring was not routinely performed in 63% of care settings, yet the majority of practitioners reported modifying their practice when providing and deciding on care for patients with frailty. Only 16% of organizations surveyed had a dedicated pathway for assessment and management of patients with frailty. A total of 37% of respondents reported access to prehabilitation services, 79% to enhanced recovery, and 27% to community rehabilitation teams. CONCLUSION: Practitioners from all groups surveyed considered that appropriate training, dedicated pathways for optimization, frailty specific performance indicators and evidence that frailty scoring had an impact on clinical outcomes and patient experience could all help to improve care for frail patients.

'Building back better' in the context of multi-hazards in the Caribbean.

The multi-hazard vulnerability of Small Island Developing States in the Caribbean has underpinned the repeated saga of destructive natural and anthropogenic events that have disrupted land, livelihoods, the economy, and society over the past several decades. Preparedness and response have been the focus of national governments and regional entities and the repeated battering calls into question the concept of recovery and 'building back better'. This paper examines the concept of recovery and 'building back better' in the context of the Caribbean, paying particular attention to the experience of the selected countries of Antigua and Barbuda, the Bahamas, Dominica, Guyana, Jamaica, and Saint Vincent and the Grenadines. These nations have recently been impacted by different disasters, ranging from storms to earthquakes to volcanic eruptions. This paper also explores the similarities among the recommendations concerning recovery needs, presenting key insights into suggested approaches for an inclusive people-centred recovery process that 'builds back better'.

Early postnatal discharge from hospital for healthy mothers and term infants.

BACKGROUND: Length of postnatal hospital stay has declined dramatically in the past 50 years. There is ongoing controversy about whether staying less time in hospital is harmful or beneficial. This is an update of a Cochrane Review first published in 2002, and previously updated in 2009. OBJECTIVES: To assess the effects of a policy of early postnatal discharge from hospital for healthy mothers and term infants in terms of important maternal, infant and paternal health and related outcomes. SEARCH METHODS: We searched the Cochrane Pregnancy and Childbirth Group's Trials Register, ClinicalTrials.gov, the WHO International Clinical Trials Registry Platform (ICTRP) (21 May 2021) and the reference lists of retrieved articles. SELECTION CRITERIA: Randomised controlled trials comparing early discharge from hospital of healthy mothers and term infants (at least 37 weeks' gestation and greater than or equal to 2500 g), with the standard care in the respective settings in which trials were conducted. Trials using allocation methods that were not truly random (e.g. based on patient number or day of the week), trials with a cluster-randomisation design and trials published only in abstract form were also eligible for inclusion. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trials for inclusion and risk of bias, extracted and checked data for accuracy, and assessed the certainty of evidence using the GRADE approach. We contacted authors of ongoing trials for additional information. MAIN RESULTS: We identified 17 trials (involving 9409 women) that met our inclusion criteria. We did not identify any trials from low-income countries. There was substantial variation in the definition of 'early discharge', ranging from six hours to four to five days. The extent of antenatal preparation and midwifery home care offered to women following discharge in intervention and control groups also varied considerably among trials. Nine trials recruited and randomised women in pregnancy, seven trials randomised women following childbirth and one did not report whether randomisation took place before or after childbirth. Risk of bias was generally unclear in most domains due to insufficient reporting of trial methods. The certainty of evidence is moderate to low and the reasons for downgrading were high or unclear risk of bias, imprecision (low numbers of events or wide 95% confidence intervals (CI)), and inconsistency (heterogeneity in direction and size of effect). Infant outcomes Early discharge probably slightly increases the number of infants readmitted within 28 days for neonatal morbidity (including jaundice, dehydration, infections) (risk ratio (RR) 1.59, 95% CI 1.27 to 1.98; 6918 infants; 10 studies; moderate-certainty evidence). In the early discharge group, the risk of infant readmission was 69 per 1000 infants compared to 43 per 1000 infants in the standard care group. It is uncertain whether early discharge has any effect on the risk of infant mortality within 28 days (RR 0.39, 95% CI 0.04 to 3.74; 4882 infants; two studies; low-certainty evidence). Early postnatal discharge probably makes little to no difference in the number of infants having at least one unscheduled medical consultation or contact with health professionals within the first four weeks after birth (RR 0.88, 95% CI 0.67 to 1.16; 639 infants; four studies; moderate-certainty evidence). Maternal outcomes Early discharge probably results in little to no difference in women readmitted within six weeks postpartum for complications related to childbirth (RR 1.12, 95% CI 0.82 to 1.54; 6992 women; 11 studies; moderate-certainty evidence) but the wide 95% CI indicates the possibility that the true effect is either an increase or a reduction in risk. Similarly, early discharge may result in little to no difference in the risk of depression within six months postpartum (RR 0.80, 95% CI 0.46 to 1.42; 4333 women; five studies; low-certainty evidence) but the wide 95% CI suggests the possibility that the true effect is either an increase or a reduction in risk. Early discharge probably results in little to no difference in women breastfeeding at six weeks postpartum (RR 1.04, 95% CI 0.96 to 1.13; 7156 women; 10 studies; moderate-certainty evidence) or in the number of women having at least one unscheduled medical consultation or contact with health professionals (RR 0.72, 95% CI 0.43 to 1.20; 464 women; two studies; moderate-certainty evidence). Maternal mortality within six weeks postpartum was not reported in any of the studies. Costs Early discharge may slightly reduce the costs of hospital care in the period immediately following the birth up to the time of discharge (low-certainty evidence; data not pooled) but it may result in little to no difference in costs of postnatal care following discharge from hospital, in the period up to six weeks after the birth (low-certainty evidence; data not pooled). AUTHORS' CONCLUSIONS: The definition of 'early discharge' varied considerably among trials, which made interpretation of results challenging. Early discharge probably leads to a higher risk of infant readmission within 28 days of birth, but probably makes little to no difference to the risk of maternal readmission within six weeks postpartum. We are uncertain if early discharge has any effect on the risk of infant or maternal mortality. With regard to maternal depression, breastfeeding, the number of contacts with health professionals, and costs of care, there may be little to no difference between early discharge and standard discharge but further trials measuring these outcomes are needed in order to enhance the level of certainty of the evidence. Large well-designed trials of early discharge policies, incorporating process evaluation and using standardized approaches to outcome assessment, are needed to assess the uptake of co-interventions. Since none of the evidence presented here comes from low-income countries, where infant and maternal mortality may be higher, it is important to conduct future trials in low-income settings.

Are trainees working in obstetrics and gynecology confident and competent in the care of frail gynecological oncology patients?

INTRODUCTION: Older patients undergoing cancer surgery are at increased risk of post-operative complications, prolonged hospital stay, and mortality. Identification of frailty can help predict patients at high risk of peri-operative complications and allow a collaborative, multidisciplinary team approach to their care. A survey was conducted to assess the confidence and knowledge of trainees in obstetrics and gynecology regarding identification and management of peri-operative issues encountered in frail gynecological oncology patients. METHODS: A web-based survey was distributed via the Audit and Research in Gynaecological Oncology (ARGO) collaborative and UK Audit and Research Collaborative in Obstetrics and Gynaecology (UKARCOG) . The survey on the management of frail peri-operative patients was disseminated to doctors-in-training (trainees) working in obstetrics and gynecology in the United Kingdom (UK) and Ireland. Specialty (ST1-7), subspecialty, and general practice trainees, non-training grade doctors, and foundation year doctors currently working in obstetrics and gynecology were eligible. Consultants were excluded. Study data were collected using REDCAP software hosted at the University of Manchester. Responses were collected over a 6-week period between January and February 2020. RESULTS: Of the 666 trainees who participated, 67% (425/666) reported inadequate training in peri-operative management of frail patients. Validated frailty assessment tools were used by only 9% (59/638) of trainees and less than 1% (4/613) were able to correctly identify all the diagnostic features of frailty. Common misconceptions included the use of chronological age and gender in frailty assessments. The majority of trainees (76.5%, 448/586) correctly answered a series of questions relating to mental capacity; however, only 6% (36/606) were able to correctly identify all three diagnostic features of delirium. A total of 87% (495/571) of trainees supported closer collaboration with geriatricians and a multidisciplinary approach. CONCLUSIONS: Obstetrics and gynecology trainees reported inadequate training in the peri-operative care of frail gynecological oncology patients, and overwhelmingly favored input from geriatricians. Routine use of validated frailty assessment tools may aid diagnosis of frailty in the peri-operative setting. There is an unmet need for formal education in the management of frail surgical patients within the UK and Irish obstetrics and gynecology curriculum.

The equine gastrointestinal microbiome: impacts of weight-loss.

BACKGROUND: Obesity is an important equine welfare issue. Whilst dietary restriction is the most effective weight-loss tool, individual animals range in their weight-loss propensity. Gastrointestinal-derived bacteria play a fundamental role in host-health and have been associated with obesity and weight-loss in other species. This study evaluated the faecal microbiome (next-generation sequencing of 16S rRNA genes) of 15 obese Welsh Mountain pony mares, in the same 11-week period across 2 years (n = 8 Year 1; n = 7 Year 2). Following a 4-week acclimation period (pre-diet phase) during which time individuals were fed the same hay to maintenance (2% body mass (BM) as daily dry matter (DM) intake), animals underwent a 7-week period of dietary restriction (1% BM hay as daily DM intake). Faeces were sampled on the final 3 days of the pre-diet phase and the final 3 days of the dietary restriction phase. Bacterial communities were determined using Next Generation Sequencing of amplified V1-V2 hypervariable regions of bacterial 16S rRNA. RESULTS: Losses in body mass ranged from 7.11 to 11.59%. Changes in the faecal microbiome composition following weight-loss included a reduction in the relative abundance of Firmicutes and Tenericutes and a reduction in indices of bacterial diversity. Pre-diet diversity was negatively associated with weight-loss. Pre-diet faecal acetate concentration was a strong predictor of subsequent weight-loss and negatively associated with Sphaerochaeta (Spirochaetes phylum) abundance. When animals were divided into 3 groups (high, mid, low) based overall weight loss, pre-diet bacterial community structure was found to have the greatest divergence between the high and low weight-loss groups (R = 0.67, p <  0.01), following PERMANOVA and ANOSIM analysis. CONCLUSIONS: Weight-loss in this group of ponies was associated with lower pre-diet faecal bacterial diversity and greater pre-diet acetate concentration. Overall, these data support a role for the faecal microbiome in weight-loss propensity in ponies and provide a baseline for research evaluating elements of the faecal microbiome in predicting weight-loss success in larger cohorts.

An in vitro investigation into the effects of 10 Hz cyclic loading on tenocyte metabolism.

Tendinopathy is a prevalent, highly debilitating condition, with poorly defined etiology. A wide range of clinical treatments has been proposed, with systematic reviews largely supporting shock wave therapy or eccentric exercise. Characterizing these treatments have demonstrated both generate perturbations within tendon at a frequency of approximately 8-12 Hz. Consequently, it is hypothesized that loading in this frequency range initiates increased anabolic tenocyte behavior, promoting tendon repair. The primary aim of this study was to investigate the effects of 10 Hz perturbations on tenocyte metabolism, comparing gene expression in response to a 10 Hz and 1 Hz loading profile. Tenocytes from healthy and tendinopathic human tendons were seeded into 3D collagen gels and subjected to 15 minutes cyclic strain at 10 Hz or 1 Hz. Tenocytes from healthy tendon showed increased expression of all analyzed genes in response to loading, with significantly increased expression of inflammatory and degradative genes with 10 Hz, relative to 1 Hz loading. By contrast, whilst the response of tenocytes from tendinopathy tendon also increased with 10 Hz loading, the overall response profile was more varied and less intense, possibly indicative of an altered healing response. Through inhibition of the pathway, IL1 was shown to be involved in the degradative and catabolic response of cells to high-frequency loading, abrogating the loading response. This study has demonstrated for the first time that loading at a frequency of 10 Hz may enhance the metabolic response of tenocytes by initiating an immediate degradatory and inflammatory cell response through the IL1 pathway, perhaps as an initial stage of tendon healing.

Wheat Vacuolar Iron Transporter TaVIT2 Transports Fe and Mn and Is Effective for Biofortification.

Increasing the intrinsic nutritional quality of crops, known as biofortification, is viewed as a sustainable approach to alleviate micronutrient deficiencies. In particular, iron deficiency anemia is a major global health issue, but the iron content of staple crops such as wheat (Triticum aestivum) is difficult to change because of genetic complexity and homeostasis mechanisms. To identify target genes for the biofortification of wheat, we functionally characterized homologs of the VACUOLAR IRON TRANSPORTER (VIT). The wheat genome contains two VIT paralogs, TaVIT1 and TaVIT2, which have different expression patterns but are both low in the endosperm. TaVIT2, but not TaVIT1, was able to rescue the growth of a yeast (Saccharomyces cerevisiae) mutant defective in vacuolar iron transport. TaVIT2 also complemented a manganese transporter mutant but not a vacuolar zinc transporter mutant. By overexpressing TaVIT2 under the control of an endosperm-specific promoter, we achieved a greater than 2-fold increase in iron in white flour fractions, exceeding minimum legal fortification levels in countries such as the United Kingdom. The antinutrient phytate was not increased and the iron in the white flour fraction was bioavailable in vitro, suggesting that food products made from the biofortified flour could contribute to improved iron nutrition. The single-gene approach impacted minimally on plant growth and also was effective in barley (Hordeum vulgare). Our results show that by enhancing vacuolar iron transport in the endosperm, this essential micronutrient accumulated in this tissue, bypassing existing homeostatic mechanisms.

Dendritic Cell Migration and Antigen Presentation Are Coordinated by the Opposing Functions of the Tetraspanins CD82 and CD37.

This study supports a new concept where the opposing functions of the tetraspanins CD37 and CD82 may coordinate changes in migration and Ag presentation during dendritic cell (DC) activation. We have previously published that CD37 is downregulated upon monocyte-derived DC activation, promotes migration of both skin and bone marrow-derived dendritic cells (BMDCs), and restrains Ag presentation in splenic and BMDCs. In this article, we show that CD82, the closest phylogenetic relative to CD37, appears to have opposing functions. CD82 is upregulated upon activation of BMDCs and monocyte-derived DCs, restrains migration of skin and BMDCs, supports MHC class II maturation, and promotes stable interactions between T cells and splenic DCs or BMDCs. The underlying mechanism involves the rearrangement of the cytoskeleton via a differential activation of small GTPases. Both CD37(-/-) and CD82(-/-) BMDCs lack cellular projections, but where CD37(-/-) BMDCs spread poorly on fibronectin, CD82(-/-) BMDCs are large and spread to a greater extent than wild-type BMDCs. At the molecular level, CD82 is a negative regulator of RhoA, whereas CD37 promotes activation of Rac-1; both tetraspanins negatively regulate Cdc42. Thus, this study identifies a key aspect of DC biology: an unactivated BMDC is CD37(hi)CD82(lo), resulting in a highly motile cell with a limited ability to activate naive T cells. By contrast, a late activated BMDC is CD37(lo)CD82(hi), and thus has modified its migratory, cytoskeletal, and Ag presentation machinery to become a cell superbly adapted to activating naive T cells.

Hospitalisation after birth of infants: cross sectional analysis of potentially avoidable admissions across England using hospital episode statistics.

BACKGROUND: Admissions of infants in England have increased substantially but there is little evidence whether this is across the first year or predominately in neonates; and for all or for specific causes. We aimed to characterise this increase, especially those admissions that may be avoidable in the context of postnatal care provision. METHODS: A cross sectional analysis of 1,387,677 infants up to age one admitted to English hospitals between April 2008 and April 2014 using Hospital Episode Statistics and live birth denominators for England from Office for National Statistics. Potentially avoidable conditions were defined through a staged process with a panel. RESULTS: The rate of hospital admission in the first year of life for physiological jaundice, feeding difficulties and gastroenteritis, the three conditions identified as potentially preventable in the context of postnatal care provision, increased by 39% (39.55 to 55.33 per 1000 live births) relative to an overall increase of 6% (334.97 to 354.55 per 1000 live births). Over the first year the biggest increase in admissions occurred in the first 0-6 days (RR 1.26, 95% CI 1.24 to 1.29) and 85% of the increase (12.36 to 18.23 per 1000 live births) in this period was for the three potentially preventable conditions. CONCLUSIONS: Most of the increase in infant hospital admissions was in the early neonatal period, the great majority being accounted for by three potentially avoidable conditions especially jaundice and feeding difficulties. This may indicate missed opportunities within the postnatal care pathway and given the enormous NHS cost and parental distress from hospital admission of infants, requires urgent attention.

Genetic differentiation within and away from the chromosomal rearrangements characterising hybridising chromosomal races of the western house mouse (Mus musculus domesticus).

The importance of chromosomal rearrangements for speciation can be inferred from studies of genetic exchange between hybridising chromosomal races within species. Reduced fertility or recombination suppression in karyotypic hybrids has the potential to maintain or promote genetic differentiation in genomic regions near rearrangement breakpoints. We studied genetic exchange between two hybridising groups of chromosomal races of house mouse in Upper Valtellina (Lombardy, Italy), using microsatellites. These groups differ by Robertsonian fusions and/or whole-arm reciprocal translocations such that F1 hybrids have a chain-of-five meiotic configuration. Previous studies showed genetic differentiation in two chromosomes in the chain-of-five (10 and 12) close to their centromeres (i.e. the rearrangement breakpoints); we have shown here that the centromeric regions of the other two chromosomes in the chain (2 and 8) are similarly differentiated. The internal chromosomes of the chain (8 and 12) show the greatest differentiation, which may reflect pairing and recombination properties of internal and external elements in a meiotic chain. Importantly, we found that centromeric regions of some non-rearranged chromosomes also showed genetic differentiation between the hybridising groups, indicating a complex interplay between chromosomal rearrangements and other parts of the genome in maintaining or promoting differentiation and potentially driving speciation between chromosomal races.

Tetraspanin CD37 Regulates ß2 Integrin-Mediated Adhesion and Migration in Neutrophils.

Deciphering the molecular basis of leukocyte recruitment is critical to the understanding of inflammation. In this study, we investigated the contribution of the tetraspanin CD37 to this key process. CD37-deficient mice showed impaired neutrophil recruitment in a peritonitis model. Intravital microscopic analysis indicated that the absence of CD37 impaired the capacity of leukocytes to follow a CXCL1 chemotactic gradient accurately in the interstitium. Moreover, analysis of CXCL1-induced leukocyte-endothelial cell interactions in postcapillary venules revealed that CXCL1-induced neutrophil adhesion and transmigration were reduced in the absence of CD37, consistent with a reduced capacity to undergo ß2 integrin-dependent adhesion. This result was supported by in vitro flow chamber experiments that demonstrated an impairment in adhesion of CD37-deficient neutrophils to the ß2 integrin ligand, ICAM-1, despite the normal display of high-affinity ß2 integrins. Superresolution microscopic assessment of localization of CD37 and CD18 in ICAM-1-adherent neutrophils demonstrated that these molecules do not significantly cocluster in the cell membrane, arguing against the possibility that CD37 regulates ß2 integrin function via a direct molecular interaction. Moreover, CD37 ablation did not affect ß2 integrin clustering. In contrast, the absence of CD37 in neutrophils impaired actin polymerization, cell spreading and polarization, dysregulated Rac-1 activation, and accelerated ß2 integrin internalization. Together, these data indicate that CD37 promotes neutrophil adhesion and recruitment via the promotion of cytoskeletal function downstream of integrin-mediated adhesion.