An open-source alignment method for multichannel infinite-conjugate microscopes using a ray transfer matrix analysis model.

Multichannel, infinite-conjugate optical systems easily allow implementation of multiple image paths and imaging modes into a single microscope. Traditional optical alignment methods which rely on additional hardware are not always simple to implement, particularly in compact open-source microscope designs. We present here an alignment algorithm and process to position the lenses and cameras in a microscope using only image magnification measurements. We show that the resulting positioning accuracy is comparable to the axial resolution of the microscope. Ray transfer matrix analysis is used to model the imaging paths when the optics are both correctly and incorrectly aligned. This is used to derive the corresponding image magnifications. We can then extract information about the lens positions using simple image-based measurements to determine whether there is misalignment of the objective lens to sample distance (working distance) and with what magnitude and direction the objective lens needs to be adjusted. Using the M4All open-source 3D printable microscope system in combination with the OpenFlexure microscope, we validate the alignment method and highlight its usability. We provide the model and an example implementation of the algorithm as an open-source Jupyter Notebook. This article is part of the Theo Murphy meeting issue 'Open, reproducible hardware for microscopy'.

Intact HIV Proviruses Persist in the Brain Despite Viral Suppression with ART.

OBJECTIVE: Human immunodeficiency virus (HIV) persistence in blood and tissue reservoirs, including the brain, is a major barrier to HIV cure and possible cause of comorbid disease. However, the size and replication competent nature of the central nervous system (CNS) reservoir is unclear. Here, we used the intact proviral DNA assay (IPDA) to provide the first quantitative assessment of the intact and defective HIV reservoir in the brain of people with HIV (PWH). METHODS: Total, intact, and defective HIV proviruses were measured in autopsy frontal lobe tissue from viremic (n = 18) or virologically suppressed (n = 12) PWH. Total or intact/defective proviruses were measured by detection of HIV pol or the IPDA, respectively, through use of droplet digital polymerase chain reaction (ddPCR). HIV-seronegative individuals were included as controls (n = 6). RESULTS: Total HIV DNA was present at similar levels in brain tissues from untreated viremic and antiretroviral (ART)-suppressed individuals (median = 22.3 vs 26.2 HIV pol copies/106 cells), reflecting a stable CNS reservoir of HIV that persists despite therapy. Furthermore, 8 of 10 viremic and 6 of 9 virally suppressed PWH also harbored intact proviruses in the CNS (4.63 vs 12.7 intact copies/106 cells). Viral reservoirs in CNS and matched lymphoid tissue were similar in the composition of intact and/or defective proviruses, albeit at lower levels in the brain. Importantly, CNS resident CD68+ myeloid cells in virally suppressed individuals harbored HIV DNA, directly showing the presence of a CNS resident HIV reservoir. INTERPRETATION: Our results demonstrate the first evidence for an intact, potentially replication competent HIV reservoir in the CNS of virally suppressed PWH. ANN NEUROL 2022;92:532-544.

Anterior approach ptosis surgery: comparison of absorbable polyglactin sutures and non-absorbable polyester sutures. Does Vicryl stand the test of time?

PURPOSE: To determine whether the long-term success of ptosis surgery is influenced by the use of absorbable or non-absorbable sutures to advance the levator aponeurosis onto the tarsal plate. METHODS: Multi-centre retrospective comparative study of re-operation rates in primary anterior approach ptosis surgery using absorbable polyglactin sutures (Vicryl) and non-absorbable polyester sutures (Ethibond). The Medisoft audit tool was used to identify all patients who underwent primary ptosis surgery for aponeurotic ptosis, performed by five oculoplastic consultants within a 7-year period, across two NHS Ophthalmology departments. The electronic patient records were reviewed for each patient. Basic demographics, suture material, and post-operative complications were recorded. All patients requiring repeat surgery between the study dates and the present day were recorded, allowing a minimum postoperative period of 3 years and 10 months. Re-operation rates in surgery using absorbable Vicryl sutures and non-absorbable Ethibond sutures were compared using Fisher's exact test. RESULTS: Four hundred and fifty-five operations in 330 patients were performed within the study period that met the inclusion and exclusion criteria. Fifty-seven percent of the patients were female, with an average age of 68.8 years. One hundred and sixty-nine operations in 128 patients were performed using absorbable Vicryl sutures. Of these, 22 (13.0%) required repeat operations. Two hundred and eighty-six operations in 202 patients were performed using non-absorbable Ethibond sutures. Of these, 17 (5.9%) required repeat operations. The two-tailed P-value was 0.0143. CONCLUSION: The use of non-absorbable Ethibond sutures to advance the levator aponeurosis onto the tarsal plate in primary ptosis surgery is associated with improved long-term success and reduced need for secondary surgery.

Nme1 and Nme2 genes exert metastasis-suppressor activities in a genetically engineered mouse model of UV-induced melanoma.

NME1 is a metastasis-suppressor gene (MSG), capable of suppressing metastatic activity in cell lines of melanoma, breast carcinoma and other cancer origins without affecting their growth in culture or as primary tumours. Herein, we selectively ablated the tandemly arranged Nme1 and Nme2 genes to assess their individual impacts on metastatic activity in a mouse model (HGF:p16-/-) of ultraviolet radiation (UVR)-induced melanoma. Metastatic activity was strongly enhanced in both genders of Nme1- and Nme2-null mice, with stronger activity in females across all genotypes. The study ascribes MSG activity to Nme2 for the first time in an in vivo model of spontaneous cancer, as well as a novel metastasis-suppressor function to Nme1 in the specific context of UVR-induced melanoma.

The Beighton Score as a measure of generalised joint hypermobility.

The Beighton Score (BS) is a set of manoeuvres in a nine-point scoring system, used as the standard method of assessment for Generalised Joint Hypermobility (GJH). It was originally developed as an epidemiological tool used in screening large populations for GJH, but later adopted as a clinical tool for diagnostic purposes. Its ability to truly reflect GJH remains controversial, as joints within the scoring system are predominantly of the upper limb and disregard many of the major joints, preventing a direct identification of GJH. Furthermore, a consistent finding in the literature whereby the BS failed to identify hypermobility in joints outside the scoring system suggests its use as an indirect indicator of GJH is also not viable. As such, the collective findings of this review demonstrate a need for a change in clinical thinking. The BS should not be used as the principle tool to differentiate between localised and generalised hypermobility, nor used alone to exclude the presence of GJH. Greater emphasis should be placed on a clinician's judgement to identify or exclude GJH, according to its full definition.

A Comparison of Training Modality and Total Genotype Scores to Enhance Sport-Specific Biomotor Abilities in Under 19 Male Soccer Players.

ABSTRACT: Suraci, BR, Quigley, C, Thelwell, RC, and Milligan, GS. A comparison of training modality and total genotype scores to enhance sport-specific biomotor abilities in under 19 male soccer players. J Strength Cond Res 35(1): 154-161, 2021-Soccer-specific training (SST) and small-sided games (SSGs) have been shown to develop physical proficiency in soccer. Research on genetics and epigenetics in the prescription of training is limited. The aims of this study were to compare the impact of 3 different SST/SSG methods and investigate if a total genotype score (TGS) influences training response. Subjects (n = 30 male soccer players, mean ± SD; age 17.2 ± 0.9 years, stature = 172.6 ± 6.2 cm; body mass = 71.7 ± 10.1 kg) were stratified into a "power" (PG) or "endurance" (EG) gene profile group, where a 15 single nucleotide polymorphism panel was used to produce an algorithmically weighted TGS. Training 1 (T1-SSGs only), training 2 (T2-SSGs/SST), and training 3 (T3-SST only) were completed (in that respective order), lasting 8 weeks each, interspersed by 4-week washouts. Acceleration (10-m sprint) was improved by T2 only (1.84 ± 0.09 seconds vs. 1.73 ± 0.05 seconds; Effect Size [ES] = 1.59, p < 0.001). Speed (30-m sprint) was improved by T2 (4.46 ± 0.22 seconds vs. 4.30 ± 0.19 seconds; ES = 0.81, p < 0.001) and T3 (4.48 ± 0.22 seconds vs. 4.35 ± 0.21 seconds; ES = 0.58, p < 0.001). Agility (T-test) was improved by T1 (10.14 ± 0.40 seconds vs. 9.84 ± 0.42 seconds; ES = 0.73, p < 0.05) and T3 (9.93 ± 0.38 seconds vs. 9.66 ± 0.45 seconds; ES = 0.66, p < 0.001). Endurance (Yo-Yo level 1) was improved by T1 (1,682.22 ± 497.23 m vs. 2,028.89 ± 604.74 m; ES = 0.63, p < 0.05), T2 (1,904.35 ± 526.77 m vs. 2,299.13 ± 606.97 m; ES = 0.69, p < 0.001), and T3 (1,851.76 ± 490.46 m vs. 2,024.35 ± 588.13 m; ES = 0.35, p < 0.05). Power (countermovement jump) was improved by T3 only (36.01 ± 5.73 cm vs. 37.14 ± 5.62 cm; ES = 0.20, p < 0.05). There were no differences in T1, T2, and T3 combined when comparing PG and EG. The PG reported significantly (χ2(20) = 4.42, p = 0.035, ES = 0.48) better training responses to T3 for power than the EG. These results demonstrate the efficacy of SSGs and SSTs in developing biomotor abilities. Although these results refute talent identification through the use of a TGS, there may be use in aligning the training method to TGS to develop power-based qualities in soccer.

What Influences Decision-Making for Cochlear Implantation in Adults? Exploring Barriers and Drivers From a Multistakeholder Perspective.

OBJECTIVES: To explore the factors influencing the uptake of cochlear implants in adults, determine the impact of each factor, and to conceptualize the journey to implantation from a multistakeholder perspective. DESIGN: Concept mapping was used to integrate input from multiple stakeholders, each with their own experience and expertise. This mixed participatory method collects qualitative and quantitative data collection and enables further quantitative analysis. There were two participant cohorts: clients (cochlear implant recipients, candidates, and family members) and professionals (cochlear implant audiologists, ear, nose, and throat surgeons, administration staff, managers. and manufacturer representatives). A total of 93 people participated in the study: client cohort (n = 60, M age = 66.60 years) and professional cohort (n = 33, M age = 45.24 years). Participants brainstormed statements in response to the question "What influences people's decision to get/not get a cochlear implant?" They subsequently grouped the statements and named each group. They rated each statement as to its impact on the decision and prioritized the need for each to be changed/improved using a five-point Likert scale. Multidimensional scaling was used to produce a visual representation of the ideas and their relationship in the form of concepts. Further analysis was conducted to determine the differences between the cohorts, subcohorts, and concepts. RESULTS: One hundred ten unique statements were generated and grouped into six concepts which either directly affected the client or their environment. These concepts were: external influences (awareness and attitude of non-implant professionals about uptake, cost, logistics, the referral pathway, public awareness); uncertainties, beliefs, and fears (fears, negative effect of word of mouth, unsuccessful previous ear surgery, cosmetics of the device, misunderstanding of how a cochlear implant functions, eligibility for an implant and outcomes after implantation); health problems (mental and physical health); hearing difficulties (social, emotional, and communication impacts of hearing loss, severity of hearing loss, benefit from and experience with hearing aids); implant professionals (implant team's attitude, knowledge and relationship with clients, quality of overall service); and goals and support (clients 'hearing desires and goals, motivation, positive impact of word of mouth, family support, having a cochlear implant mentor. The six concepts fell into two overarching domains: the client-driven domain with four concepts and the external domain with two concepts. The mean rating of concepts in terms of impact on a client's decision to get an implant ranged from 2.24 (external influences, the main barrier) to 4.45 (goals and support, the main driver). Ratings significantly differed between the client and professional cohorts. CONCLUSIONS: This study increases our understanding of the factors, which influence a client's decision choose a cochlear implant as a hearing treatment. It also provides new information on the influence of the other stakeholders on the client journey. The magnitude of the generated statements in the client-driven domain highlights the pivotal role of individualized care in clinical settings in influencing a client's decision and the need for the professionals to understand a client's needs and expectations. A client's persistent hearing difficulties, goals, and support network were identified as drivers to the uptake of cochlear implants. However, the barriers identified highlight the need for a collaborative multi- and interdisciplinary approach to raise awareness in and educate non-implant hearing professionals about the cochlear implant process, as well as providing information to empower clients to make educated decisions and consider a cochlear implant as a hearing management option.

The thermal demands of flood rescue and impacts on task performance.

The aim of this study was to determine the thermal demand of simulated Flood Rescue tasks and impacts on performance. Ten participants undertook two simulations: 'Cold' (4 °C) -participants stood in knee height moving water (4.8 km·h-1), with simulated wind and rain for 60 min. 'Warm' (20 °C) - participants performed 6x7 min walking in knee height moving water (3.2 km·h-1), pulling 10 kg. Grip strength, manual dexterity, and jump height were measured pre and post. The cold resulted in cooling of the great toe and finger (9.98 [0.84]°C and 10.38 [8.21-12.1] °C, respectively). Jump height, manual dexterity and grip strength fell by 20%, 22% and ∼13%, respectively. In the 'Warm': heart rates were 157 (19) b·min-1, oxygen consumption 30.62 (7.83) mL.kg-1·min-1, and sweat loss 1.06 (0.31) L. There were no differences in the physical tests. Flood Rescue represents significant, but different, challenges. Remaining static in the cold resulted in peripheral neuromuscular cooling, whilst exercising in the warm resulted in a significant thermal challenge. Practitioner Summary: Little is known about the physical requirements, thermal profiles and optimum personal protective equipment for flood rescue. Flood rescue represents significant challenges. In the cold, emergency responders may be incapacitated by peripheral cooling. In the heat, they may be incapacitated by heat-related exhaustion. Consideration should be given to these risks.

A life fulfilled: positively influencing physical activity in older adults - a systematic review and meta-ethnography.

BACKGROUND: Increasing physical activity in older adults remains a key public health priority in countries with a high burden of non-communicable disease, yet current interventions have failed to substantially increase population uptake with UK data suggesting that only half of 65-74 year olds report meeting recommended levels. The aim of this study was to conduct a systematic and inductive qualitative synthesis of the large body of qualitative research describing what influences physical activity at this age, and older adults' experiences of physical activity. METHODS: A qualitative meta-ethnography was chosen as the study design as this inductive approach can provide novel insights and generate new theory about physical activity and ageing. Papers were identified by searching electronic databases and key citations. Peer-reviewed primary qualitative studies and systematic reviews were included if they met the following inclusion criteria: community-dwelling participants aged 60 years or older or in the retirement transition period; reporting on leisure-time physical activity; utilising a rigorous qualitative methodology. A line of argument approach was employed to generate a theory about how older adults think and feel about physical activity. RESULTS: Thirty-nine papers met the inclusion criteria and were synthesised. The emergent theory suggested transition to older age can challenge people's sense of self and their role in life. Physical activity can help in regaining feelings of purpose, of being needed in collective group activity, and by creating habitual routine and structure to the day. In overcoming real and perceived barriers, and by taking up or sustaining physical activities, older adults can further build self-esteem all of which contributes to a fulfilling older age. CONCLUSION: Current failures to increase population levels of physical activity in older adults may be explained by an approach overly focused on the health benefits of activity. Insights from this study suggest we need to reframe our approach to consider the wider set of goals and aspirations which are of greater personal importance to older adults, and future interventions should focus on how physical activity can contribute to life satisfaction, sense of purpose, and sense of role fulfilment in older age. TRIAL REGISTRATION: Registered prospectively on PROSPERO on 29th March 2013: CRD42013003796 .

A Risk Assessment Framework for the Socioeconomic Impacts of Electricity Transmission Infrastructure Failure Due to Space Weather: An Application to the United Kingdom.

Space weather phenomena have been studied in detail in the peer-reviewed scientific literature. However, there has arguably been scant analysis of the potential socioeconomic impacts of space weather, despite a growing gray literature from different national studies, of varying degrees of methodological rigor. In this analysis, we therefore provide a general framework for assessing the potential socioeconomic impacts of critical infrastructure failure resulting from geomagnetic disturbances, applying it to the British high-voltage electricity transmission network. Socioeconomic analysis of this threat has hitherto failed to address the general geophysical risk, asset vulnerability, and the network structure of critical infrastructure systems. We overcome this by using a three-part method that includes (i) estimating the probability of intense magnetospheric substorms, (ii) exploring the vulnerability of electricity transmission assets to geomagnetically induced currents, and (iii) testing the socioeconomic impacts under different levels of space weather forecasting. This has required a multidisciplinary approach, providing a step toward the standardization of space weather risk assessment. We find that for a Carrington-sized 1-in-100-year event with no space weather forecasting capability, the gross domestic product loss to the United Kingdom could be as high as £15.9 billion, with this figure dropping to £2.9 billion based on current forecasting capability. However, with existing satellites nearing the end of their life, current forecasting capability will decrease in coming years. Therefore, if no further investment takes place, critical infrastructure will become more vulnerable to space weather. Additional investment could provide enhanced forecasting, reducing the economic loss for a Carrington-sized 1-in-100-year event to £0.9 billion.

Development of a physical employment standard for a branch of the UK military.

A Physical Employment Standard (PES) was developed for the British Royal Air Force Regiment (RAF Regt). Twenty-nine RAF Regt personnel completed eight critical tasks wearing Combat Equipment Fighting Order (31.5 kg) while being monitored for physical and perceptual effort. A PES was developed using task simulations, measured on 61 incumbents. The resultant PES consists of: 1) a battlefield test involving task simulations: single lift and point-of-entry (psss/fail); timed elements (react to effective enemy fire and crawl) set at 95th performance percentile; casualty evacuation (CASEVAC) casualty drag and CASEVAC simulated stretcher carry completed without stopping. 2) a Multi Stage Fitness Test level 9.10 to assess aerobic fitness to complete a tactical advance to battle. The task-based PES should ensure RAF Regt personnel have a baseline level of fitness to perform and withstand the physical demands of critical tasks to at least a minimum acceptable standard. Practitioner summary: A Physical Employment Standard (PES) was developed for the British RAF Regiment by measuring the physiological demands of critical tasks on a representative cohort of incumbent personnel. A task-based PES should ensure that only those candidates, irrespective of gender, race or disability, with the necessary physical attributes to succeed in training and beyond, are selected.

Nuclear functions of NME proteins.

The NME family of proteins is composed of 10 isoforms, designated NME1-10, which are diverse in their enzymatic activities and patterns of subcellular localization. Each contains a conserved domain associated with a nucleoside diphosphate kinase (NDPK) function, although not all are catalytically active. Several of the NME isoforms (NME1, NME5, NME7, and NME8) also exhibit a 3'-5' exonuclease activity, suggesting roles in DNA proofreading and repair. NME1 and NME2 have been shown to translocate to the nucleus, although they lack a canonical nuclear localization signal. Binding of NME1 and NME2 to DNA does not appear to be sequence-specific in a strict sense, but instead is directed to single-stranded regions and/or other non-B-form structures. NME1 and NME2 have been identified as potential canonical transcription factors that regulate gene transcription through their DNA-binding activities. Indeed, the NME1 and NME2 isoforms have been shown to regulate gene expression programs in a number of cellular settings, and this regulatory function has been proposed to underlie their well-recognized ability to suppress the metastatic phenotype of cancer cells. Moreover, NME1 and, more recently, NME3, have been implicated in repair of both single- and double-stranded breaks in DNA. This suggests that reduced expression of NME proteins could contribute to the genomic instability that drives cancer progression. Clearly, a better understanding of the nuclear functions of NME1 and possibly other NME isoforms could provide critical insights into mechanisms underlying malignant progression in cancer. Indeed, clinical data indicate that the subcellular localization of NME1 may be an important prognostic marker in some cancers. This review summarizes putative functions of nuclear NME proteins in DNA binding, transcription, and DNA damage repair, and highlights their possible roles in cancer progression.

The HGF/SF Mouse Model of UV-Induced Melanoma as an In Vivo Sensor for Metastasis-Regulating Gene.

Cutaneous malignant melanoma is an aggressive and potentially lethal form of skin cancer, particularly in its advanced and therapy-resistant stages, and the need for novel therapeutics and prognostic tools is acute. Incidence of melanoma has steadily increased over the past few decades, with exposure to the genome-damaging effects of ultraviolet radiation (UVR) well-recognized as a primary cause. A number of genetically-engineered mouse models (GEMMs) have been created that exhibit high incidence of spontaneous and induced forms of melanoma, and a select subset recapitulates its progression to aggressive and metastatic forms. These GEMMs hold considerable promise for providing insights into advanced stages of melanoma, such as potential therapeutic targets and prognostic markers, and as in vivo systems for testing of novel therapies. In this review, we summarize how the HGF/SF transgenic mouse has been used to reveal metastasis-regulating activity of four different genes (CDK4R24C, survivin and NME1/NME2) in the context of UV-induced melanoma. We also discuss how these models can potentially yield new strategies for clinical management of melanoma in its most aggressive forms.

The Amphimedon queenslandica genome and the evolution of animal complexity.

Sponges are an ancient group of animals that diverged from other metazoans over 600 million years ago. Here we present the draft genome sequence of Amphimedon queenslandica, a demosponge from the Great Barrier Reef, and show that it is remarkably similar to other animal genomes in content, structure and organization. Comparative analysis enabled by the sequencing of the sponge genome reveals genomic events linked to the origin and early evolution of animals, including the appearance, expansion and diversification of pan-metazoan transcription factor, signalling pathway and structural genes. This diverse 'toolkit' of genes correlates with critical aspects of all metazoan body plans, and comprises cell cycle control and growth, development, somatic- and germ-cell specification, cell adhesion, innate immunity and allorecognition. Notably, many of the genes associated with the emergence of animals are also implicated in cancer, which arises from defects in basic processes associated with metazoan multicellularity.

Understanding large scale sequencing datasets through changes to protein folding.

The expansion of high-quality, low-cost sequencing has created an enormous opportunity to understand how genetic variants alter cellular behaviour in disease. The high diversity of mutations observed has however drawn a spotlight onto the need for predictive modelling of mutational effects on phenotype from variants of uncertain significance. This is particularly important in the clinic due to the potential value in guiding clinical diagnosis and patient treatment. Recent computational modelling has highlighted the importance of mutation induced protein misfolding as a common mechanism for loss of protein or domain function, aided by developments in methods that make large computational screens tractable. Here we review recent applications of this approach to different genes, and how they have enabled and supported subsequent studies. We further discuss developments in the approach and the role for the approach in light of increasingly high throughput experimental approaches.

Modelling electrified railway signalling misoperations during extreme space weather events in the UK.

Space weather has the potential to impact ground-based technologies on Earth, affecting many systems including railway signalling. This study uses a recently developed model to analyse the impact of geomagnetically induced currents on railway signalling systems in the United Kingdom during the March 1989 and October 2003 geomagnetic storms. The March 1989 storm is also scaled to estimate a 1-in-100 year and a 1-in-200 year extreme storm. Both the Glasgow to Edinburgh line, and the Preston to Lancaster section of the West Coast Main Line are modelled. No "right side" failures (when unoccupied sections appear occupied) are suggested to have occurred during either storm, and the total number of potential "wrong side" failures (when occupied sections appear clear) is low. However, the modelling indicates "right side" and "wrong side" failures are possible on both routes during the 1-in-100 year and 1-in-200 year extreme storms, with the Glasgow to Edinburgh line showing more total misoperations than the Preston to Lancaster section of the West Coast Main Line. A 1-in-100 year or 1-in-200 year extreme storm would result in misoperations over an extended period of time, with most occurring over a duration of 2-3 h either side of the peak of the storm.

The development and validation of a Multidimensional Perceived Work Ability Scale.

Research on the concept of existing unidimensional Perceived Work Ability scale (PWA) in organizational science has recently increased due to its prediction of important work, individual, and labor force outcomes. To date, PWA has been measured as a unidimensional construct. The present study outlines the need for the multidimensional conceptualization of PWA and its measurement. We describe the development and validation of the Multidimensional Perceived Work Ability Scale (M-PWAS), comprising four dimensions: physical, cognitive, interpersonal, and emotional. In line with Hinkin's (1998) approach to scale validation, we use four samples (total N = 1,152) to establish the M-PWAS as a reliable and valid measure of PWA. Through an iterative item generation and review process, we found evidence for content validity. Furthermore, each subscale demonstrated high internal consistency and factorial validity, and analysis of the PWA nomological network demonstrated evidence for convergent and discriminant validity. Finally, we found that the M-PWAS showed incremental validity over an existing unidimensional PWA measure in the prediction of perceived stress, emotional exhaustion, work engagement, and turnover. We discuss implications for theory, research, and workplace interventions. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Pathways associated with reduced quadriceps oxidative fibres and endurance in COPD.

Reduced quadriceps endurance in chronic obstructive pulmonary disease (COPD) is associated with a predominance of type II glycolytic fibres over type I oxidative fibres (fibre shift) and reduced muscle energy stores. The molecular mechanisms responsible for this remain unknown. We hypothesised that expression of known regulators of type I fibres and energy production in quadriceps muscle would differ in COPD patients with and without fibre shift. We measured lung function, physical activity, exercise performance, quadriceps strength and endurance (nonvolitionally) in 38 Global Initiative for Chronic Obstructive Lung Disease stage I-IV COPD patients and 23 healthy age-matched controls. Participants underwent a quadriceps biopsy: type I and II fibre proportions were determined using immunohistochemistry and fibre shift defined using published reference ranges. Calcineurin A, phosphorylated AMP kinase (phospho-AMPK)-α, protein kinase A-α catalytic subunits, modulators of calcineurin activity and calmodulin, 14-3-3 proteins were measured by Western blotting, and myocyte-enriched calcineurin-interacting protein-1 mRNA measured by quantitative PCR. Downstream, nuclear myocyte enhancer factor-2 capable of DNA binding was quantified by transcription factor ELISA. Unexpectedly, calcineurin expression was higher, while phospho-AMPK was lower, in COPD patients with fibre shift compared to COPD patients without fibre shift. Phospho-AMPK levels correlated with quadriceps endurance in patients. Reduced phospho-AMPK may contribute to reduced quadriceps oxidative capacity and endurance in COPD.

Plant WEE1 kinase is cell cycle regulated and removed at mitosis via the 26S proteasome machinery.

In yeasts and animals, premature entry into mitosis is prevented by the inhibitory phosphorylation of cyclin-dependent kinase (CDK) by WEE1 kinase, and, at mitosis, WEE1 protein is removed through the action of the 26S proteasome. Although in higher plants WEE1 function has been confirmed in the DNA replication checkpoint, Arabidopsis wee1 insertion mutants grow normally, and a role for the protein in the G2/M transition during an unperturbed plant cell cycle is yet to be confirmed. Here data are presented showing that the inhibitory effect of WEE1 on CDK activity in tobacco BY-2 cell cultures is cell cycle regulated independently of the DNA replication checkpoint: it is high during S-phase but drops as cells traverse G2 and enter mitosis. To investigate this mechanism further, a yeast two-hybrid screen was undertaken to identify proteins interacting with Arabidopsis WEE1. Three F-box proteins and a subunit of the proteasome complex were identified, and bimolecular fluorescence complementation confirmed an interaction between AtWEE1 and the F-box protein SKP1 interacting partner 1 (SKIP1). Furthermore, the AtWEE1-green fluorescent protein (GFP) signal in Arabidopsis primary roots treated with the proteasome inhibitor MG132 was significantly increased compared with mock-treated controls. Expression of AtWEE1-YFP(C) (C-terminal portion of yellow fluorescent protein) or AtWEE1 per se in tobacco BY-2 cells resulted in a premature increase in the mitotic index compared with controls, whereas co-expression of AtSKIP1-YFP(N) negated this effect. These data support a role for WEE1 in a normal plant cell cycle and its removal at mitosis via the 26S proteasome.

Heterogeneity of quadriceps muscle phenotype in chronic obstructive pulmonary disease (Copd); implications for stratified medicine?

INTRODUCTION: Quadriceps muscle dysfunction is common in COPD. Determining, and, if possible, predicting quadriceps phenotype in COPD is important for patient stratification for therapeutic trials. METHODS: In biopsies from 114 COPD patients and 30 controls, we measured fiber size and proportion and assessed the relationship with quadriceps function (strength and endurance), clinical phenotype (lung function, physical activity, fat-free mass) and exercise performance. In a subset (n = 40) we measured muscle mid-thigh cross-sectional area by computed tomography. RESULTS: Normal ranges for fiber proportions and fiber cross-sectional area were defined from controls; we found isolated fiber shift in 31% of patients, isolated fiber (predominantly type II) atrophy in 20%, both shift and atrophy in 25%, and normal fiber parameters in 24%. Clinical parameters related poorly to muscle biopsy appearances. CONCLUSIONS: Quadriceps morphology is heterogeneous in COPD and cannot be predicted without biopsy, underlining the need for biomarkers.