Paxillin and focal adhesion kinase colocalise in human skeletal muscle and its associated microvasculature.

Focal adhesion kinase (FAK) and paxillin are functionally linked hormonal- and mechano-sensitive proteins. We aimed to describe paxillin's subcellular distribution using widefield and confocal immunofluorescence microscopy and test the hypothesis that FAK and paxillin colocalise in human skeletal muscle and its associated microvasculature. Percutaneous muscle biopsies were collected from the m. vastus lateralis of seven healthy males, and 5-µm cryosections were stained with anti-paxillin co-incubated with anti-dystrophin to identify the sarcolemma, anti-myosin heavy chain type I for fibre-type differentiation, anti-dihydropyridine receptor to identify T-tubules, lectin UEA-I to identify the endothelium of microvessels and anti-α-smooth muscle actin to identify vascular smooth muscle cells (VSMC). Colocalisation of anti-paxillin with anti-dystrophin or anti-FAK was quantified using Pearson's correlation coefficient on confocal microscopy images. Paxillin was primarily present in (sub)sarcolemmal regions of skeletal muscle fibres where it colocalised with dystrophin (r = 0.414 ± 0.026). The (sub)sarcolemmal paxillin immunofluorescence intensity was ~2.4-fold higher than in sarcoplasmic regions (P < 0.001) with sarcoplasmic paxillin immunofluorescence intensity ~10 % higher in type I than in type II fibres (P < 0.01). In some longitudinally orientated fibres, paxillin formed striations that corresponded to the I-band region. Paxillin immunostaining was highest in endothelial and VSMC and distributed heterogeneously in both cell types. FAK and paxillin colocalised at (sub)sarcolemmal regions and within the microvasculature (r = 0.367 ± 0.036). The first images of paxillin in human skeletal muscle suggest paxillin is present in (sub)sarcolemmal and I-band regions of muscle fibres and within the microvascular endothelium and VSMC. Colocalisation of FAK and paxillin supports their suggested role in hormonal and mechano-sensitive signalling.

Person-centred care in the Indonesian health-care system.

Person-centred care (PCC) is defined as the health-care providers selecting and delivering interventions or treatments that are respectful of and responsive to the characteristics, needs, preferences and values of the individual person. This model of care puts the person at the centre of care delivery. The World Health Organization suggests that PCC is one of the essential dimensions of health care and as such is an important indicator of health-care quality. However, how PCC is implemented differs between countries in response to local cultures, resources and consumer expectations of health care. This article discusses person-centred care in the Indonesian health-care system.

Enhancing Return to Alpine Skiing: Integrating Perceptual-Motor-Cognitive Considerations in Testing and Progressions: A Clinical Commentary.

Alpine skiing poses significant risks for anterior cruciate ligament (ACL) injury at both recreational and professional levels, which is compounded by high rates of re-injury. Despite the existence of return to sport (RTS) and return to snow protocols, the frequency of ACL re-injury has not been mitigated, raising doubts about protocol effectiveness. Current RTS protocols primarily focus on biomechanical and neuromuscular factors in isolation, neglecting the important perceptual-motor-cognitive changes associated with ACL injuries and the high cognitive demands of skiing. The purpose of this clinical commentary is to address the perceptual-motor-cognitive demands specific to alpine skiing, evaluate RTS testing for skiers, and propose updated standards for testing and return to snow progressions that incorporate these considerations. Level of Evidence: 5.

Advice only versus advice and a physiotherapy programme for acute traumatic anterior shoulder dislocation: the ARTISAN RCT.

Background: The extra benefit of a programme of physiotherapy in addition to advice alone, following first-time traumatic shoulder dislocation, is uncertain. We compared the clinical and cost-effectiveness of a single session of advice with a single session of advice and a programme of physiotherapy. Objective: The primary objective was to quantify and draw inferences about observed differences in the Oxford Shoulder Instability Score between the trial treatment groups 6 months post randomisation, in adults with a first-time traumatic shoulder dislocation. Design: A pragmatic, multicentre, superiority, randomised controlled trial with embedded qualitative study. Setting: Forty-one hospitals in the UK NHS. Participants: Adults with a radiologically confirmed first-time traumatic anterior shoulder dislocation, being managed non-operatively. People with neurovascular complications or bilateral dislocations, and those unable to adhere to trial procedures or unable to attend physiotherapy within 6 weeks of injury, or who had previously been randomised, were excluded. Interventions: All participants received the same initial shoulder examination followed by advice to aid self-management, lasting up to 1 hour and administered by a physiotherapist (control). Participants randomised to receive an additional programme of physiotherapy were offered sessions lasting for up to 30 minutes, over a maximum duration of 4 months from the date of randomisation (intervention). Main outcome measures: The primary outcome measure was the Oxford Shoulder Instability Score. This is a self-completed outcome measure containing 12 questions (0-4 points each), with possible scores from 0 (worst function) to 48 (best function). Measurements were collected at 6 weeks, 3 months, 6 months and 12 months by postal questionnaire; 6 months was the primary outcome time point. The primary health outcome for economic evaluation was the quality-adjusted life-year, in accordance with National Institute of Health and Care Excellence guidelines. Results: Between 14 November 2018 and 14 March 2022, 482 participants were randomised to advice (n = 240) or advice and a programme of physiotherapy (n = 242). Participants were 34% female, with a mean age of 45 years, and treatment arms were balanced at baseline. There was not a statistically significant difference in the primary outcome between advice only and advice plus a programme of physiotherapy at 6 months for the primary intention-to-treat adjusted analysis (favours physiotherapy: 1.5, 95% confidence interval -0.3 to 3.5) or at earlier 3-month and 6-week time points on the Oxford Shoulder Instability Score (0-48; higher scores indicate better function). The probability of physiotherapy being cost-effective at a willingness-to-pay threshold of £30,000 was 0.95. Conclusions: We found little difference in the primary outcome or other secondary outcomes. Advice with additional physiotherapy sessions was found likely to be cost-effective. However, small imprecise incremental costs and quality-adjusted life-years raise questions on whether it is the best use of scarce physiotherapy resources given current service demands. Limitations: Loss to follow-up was 27%; however, the observed standard deviation was much smaller than anticipated. These changes in parameters reduced the number of participants required to observe the planned target difference of four points. Our post hoc sensitivity analysis, accounting for missing data, gives similar results. Future work: Further research should be directed towards optimising self-management strategies. Study registration: This study is registered as ISRCTN63184243. Funding: This award was funded by the National Institute for Health and Care Research (NIHR) Health Technology Assessment programme (NIHR award ref: 16/167/56) and is published in full in Health Technology Assessment; Vol. 28, No. 22. See the NIHR Funding and Awards website for further award information.

The shoulder dislocates (comes out of its socket joint) when the upper end of the arm bone is forced out during an injury. This common problem occurs mostly in men in their 20s and women aged over 80. After the bone is put back in its socket, most people are managed with physiotherapy. In the United Kingdom, once the bone is back in its socket, there is a range of physiotherapy provision: some hospitals offer advice, and some offer advice and a course of additional physiotherapy sessions. We compared advice alone to advice and physiotherapy for people who had a shoulder that had come out of its joint for the first time. Physiotherapy advice and additional sessions included education about the injury and exercises to move and strengthen the shoulder. When we started this project, this was the first time these two treatments had been compared. Our aim was to compare what activities the two groups could do 6 months after injury via a questionnaire. We also compared quality of life and the cost of rehabilitation at 6 weeks, 3 months, 6 months and 12 months after injury. Adults with a shoulder out of its joint and who were not having surgery were asked to take part. All adults who were eligible and consented to take part were assigned, by chance, to either a single session of advice or the same session followed by physiotherapy. Between 14 November 2018 and 14 March 2022 we collected data on 482 people, from 41 NHS sites across the UK. We found at 6 months there was little evidence that additional physiotherapy was better, when compared to advice alone. Cost-effectiveness analysis (comparing changes in costs and quality of life) suggests additional physiotherapy might provide value for money. However, the changes involved are small and uncertain.

Acute rehabilitation following traumatic anterior shoulder dislocation (ARTISAN): pragmatic, multicentre, randomised controlled trial.

OBJECTIVE: To assess the effects of an additional programme of physiotherapy in adults with a first-time traumatic shoulder dislocation compared with single session of advice, supporting materials, and option to self-refer to physiotherapy. DESIGN: Pragmatic, multicentre, randomised controlled trial (ARTISAN). SETTING AND PARTICIPANTS: Trauma research teams at 41 UK NHS Trust sites screened adults with a first time traumatic anterior shoulder dislocation confirmed radiologically, being managed non-operatively. People were excluded if they presented with both shoulders dislocated, had a neurovascular complication, or were considered for surgical management. INTERVENTIONS: One session of advice, supporting materials, and option to self-refer to physiotherapy (n=240) was assessed against the same advice and supporting materials and an additional programme of physiotherapy (n=242). Analyses were on an intention-to-treat basis with secondary per protocol analyses. MAIN OUTCOME MEASURES: The primary outcome was the Oxford shoulder instability score (a single composite measure of shoulder function), measured six months after treatment allocation. Secondary outcomes included the QuickDASH, EQ-5D-5L, and complications. RESULTS: 482 participants were recruited from 40 sites in the UK. 354 (73%) participants completed the primary outcome score (n=180 allocated to advice only, n=174 allocated to advice and physiotherapy). Participants were mostly male (66%), with a mean age of 45 years. No significant difference was noted between advice compared with advice and a programme of physiotherapy at six months for the primary intention-to-treat adjusted analysis (between group difference favouring physiotherapy 1.5 (95% confidence interval -0.3 to 3.5)) or at earlier three month and six week timepoints. Complication profiles were similar across the two groups (P>0.05). CONCLUSIONS: An additional programme of current physiotherapy is not superior to advice, supporting materials, and the option to self-refer to physiotherapy. TRIAL REGISTRATION: Current Controlled Trials ISRCTN63184243.

Meniscal Transplant surgery or Optimised Rehabilitation full randomised trial (MeTeOR2): a study protocol.

INTRODUCTION: Pain and disability after meniscectomy can be a substantial lifelong problem. There are few treatment options, especially for young people. Non-surgical management (rehabilitation) is an option but increasingly surgeons are performing meniscal allograft transplants (MATs) for these individuals. However, this is still an uncommon procedure, and availability and usage of MAT vary widely both in the UK and internationally. It is not known which treatment option is the most effective and cost-effective. METHODS AND ANALYSIS: The Meniscal Transplant surgery or Optimised Rehabilitation trial is an international, multicentre, randomised controlled trial. The aim is to compare the clinical and cost effectiveness of MAT versus an optimised package of individualised, progressive, rehabilitation that we have called personalised knee therapy (PKT).Participants will be recruited from sites across the UK, Australia, Canada and Belgium. The planned 144 participants provide at least 90% power to detect a 10-point difference in the Knee injury and Osteoarthritis Outcome Score (KOOS4) at 24-months post randomisation (primary outcome). A prospectively planned economic evaluation will be conducted from a healthcare system and personal social services perspective. Secondary outcome data including health utility, occupational status, sports participation, mental well-being, further treatment, and adverse events will be collected at 3, 6, 12, 18, and 24 months. Analysis will be on an intention-to-treat basis and reported in-line with the Consolidated Standards of Reporting Trials statement. ETHICS AND DISSEMINATION: The trial was approved by the London-Bloomsbury Research Ethics Committee on 19 August 2022 (22/LO/0327) and Northern Sydney Local Health District Human Research Ethics Committee, NSW, Australia on the 13 March 2023 (2022/ETH01890).Trial results will be disseminated via peer-reviewed publications, presentations at international conferences, in lay summaries and using social media as appropriate.This protocol adheres to the recommended Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) checklist. TRIAL REGISTRATION NUMBER: ISRCTN87336549.

Developing evidence-based practice champions in the Maldives.

Evidence-based practice (EBP) is an approach that has gained recognition for facilitating the transfer of evidence into clinical practice. EBP champions is a strategy that can be adopted to encourage the uptake of EBP. This paper describes an action research project that was undertaken in Maldives. EBP champion model has been introduced in the Maldives early 2012 and aims to produce clinical leaders from variety of backgrounds who could implement EBP. This paper provides an extended discussion of the process that was undertaken to prepare EBP champions and their roles in implementing EBP.

Normative Values of Isometric Shoulder Strength Among Healthy Adults.

Background: Normative data is useful for comparing measured values of strength with population norms and can avoid the issues associated with limb symmetry index. The available normative shoulder strength values are limited by constraints on research designs and variability in subject groups which prevents this data being successfully extrapolated to the greater population. Purpose: The purpose of this study was to establish normative isometric strength values for various movements of the shoulder that are specific to function and rotator cuff strength. A secondary goal of this study was to analyze the effect of age, gender, weight, height, activity level and arm dominance on shoulder strength. Design: Observational cohort study. Methods: Subjects in four age groups (20-29, 30-39, 40-49, 50-59) were included in this study-200 males (40.0 ± 11.6 years, 179.1 ± 6.5 cm, 81 ± 13.0 kg) and 200 females (40.1 ± 11.5 years, 165.3 ± 7.4sm, 64.4 ± 11.6 kg). Bilateral isometric strength measurements were taken with a handheld dynamometer testing seven shoulder movements. Tables of normative strength data were constructed. Multivariate analyses were performed to analyze the effects of age, gender, weight, height and activity level on isometric shoulder strength. Results: Men were stronger than women (p<0.001). Age was not associated with most strength measures with the exception of dominant arm abduction (p<0.004), non-dominant arm abduction (p<0.028) and non-dominant arm scapular plane abduction (p<0.004) which had a negative association with strength. Weight was positively associated with strength (p<0.001). Activity level was positively associated with all strength measures (p<0.05) except dominant sided abduction (p=0.056). There were no statistically significant differences between dominant and non-dominant sides. Conclusion: This normative data may be useful to the clinician, as it permits a standard against which to compare shoulder strength for various age groups. Clinicians can have confidence that the uninvolved limb, if symptom free, can be used as an adequate benchmark for strength measures. Levels of Evidence: Level 3©The Author(s).

Criteria-Based Rehabilitation Following Revision Hip Arthroscopy: A Clinical Commentary.

Hip revision arthroscopy is becoming an increasingly popular surgery for those with unsatisfactory outcomes following primary hip arthroscopy. With the relatively uncommon but potentially increased difficulty of rehabilitation from this surgery, a lack of established research regarding rehabilitative programs remains. Therefore, the purpose of this clinical commentary is to propose a criterion-based progression that considers the intricacies present following a hip revision arthroscopy from early rehabilitation through return to sport. Criteria are presented clearly to promote objective progression through rehabilitation as opposed to relying on time since surgery as revision surgeries do not always follow traditional tissue healing time-frames. This criterion based progression promotes range of motion (ROM), strength, gait, neuromuscular control, load introduction and gradual return to play. Level of Evidence: 5.

UK robotic arthroplasty clinical and cost effectiveness randomised controlled trial for hips (RACER-Hip): a study protocol.

INTRODUCTION: The number of robotic-assisted hip replacement procedures has expanded globally with the intended aim of improving outcomes. Intraoperative robotic-arm systems add additional costs to total hip replacement (THR) surgery but may improve surgical precision and could contribute to diminished pain and improved function. Additionally, these systems may reduce the need for expensive revision surgery. Surgery with conventional instruments may be just as successful, quick and affordable. There is timely demand for a robust evaluation of this technology. METHODS AND ANALYSIS: The Robotic Arthroplasty Clinical and cost Effectiveness Randomised controlled trial for Hips (RACER-Hip) is a multicentre (minimum of six UK sites), participant-assessor blinded, randomised controlled trial. 378 participants with hip osteoarthritis requiring THR will be randomised (1:1) to receive robotic-assisted THR, or THR using conventional surgical instruments. The primary outcome is the Forgotten Joint Score at 12 months post-randomisation; a patient-reported outcome measure assessing participants' awareness of their joint when undertaking daily activities. Secondary outcomes will be collected post-operatively (pain, blood loss and opioid usage) and at 3, 6, 12, 24 months, then 5 and 10 years postrandomisation (including function, pain, health-related quality of life, reoperations and satisfaction). Allocation concealment will be accomplished using a computer-based randomisation procedure on the day of surgery. Blinding methods include the use of sham incisions for marker clusters and blinded operation notes. The primary analysis will adhere to the intention-to-treat principle. Results will adhere to Consolidated Standards of Reporting Trials statements. ETHICS AND DISSEMINATION: The trial was approved by an ethics committee (Solihull Research Ethics Committee, 30 June 2021, IRAS: 295831). Participants will provide informed consent before agreeing to participate. Results will be disseminated using peer-reviewed journal publications, presentations at international conferences and through the use of social media. We will develop plans to disseminate to patients and public with our patient partners. TRIAL REGISTRATION NUMBER: ISRCTN13374625.

Residues 155 and 348 contribute to the determination of P2X7 receptor function via distinct mechanisms revealed by single-nucleotide polymorphisms.

P2X(7) receptors are important in mediating the physiological functions of extracellular ATP, and altered receptor expression and function have a causative role in the disease pathogenesis. Here, we investigated the mechanisms determining the P2X(7) receptor function by following two human single-nucleotide polymorphism (SNP) mutations that replace His-155 and Ala-348 in the human (h) P2X(7) receptor with the corresponding residues, Tyr-155 and Thr-348, in the rat (r) P2X(7) receptor. H155Y and A348T mutations in the hP2X(7) receptor increased ATP-induced currents, whereas the reciprocal mutations, Y155H and T348A, in the rP2X(7) receptor caused the opposite effects. Such a functional switch is a compelling indication that these residues are critical for P2X(7) receptor function. Additional mutations of His-155 and Ala-348 in the hP2X(7) receptor to residues with diverse side chains revealed a different dependence on the side chain properties, supporting the specificity of these two residues. Substitutions of the residues surrounding His-155 and Ala-348 in the hP2X(7) receptor with the equivalent ones in the rP2X(7) receptor also affected ATP-induced currents but were not fully reminiscent of the H155Y and A348T effects. Immunofluorescence imaging and biotin labeling assays showed that H155Y in the hP2X(7) receptor increased and Y155H in the rP2X(7) receptor decreased cell-surface expression. Such contrasting effects were not obvious with the reciprocal mutations of residue 348. Taken together, our results suggest that residues at positions 155 and 348 contribute to P2X(7) receptor function via determining the surface expression and the single-channel function, respectively. Such interpretations are consistent with the locations of the residues in the structural model of the hP2X(7) receptor.

Latarjet Procedure for the Treatment of Anterior Glenohumeral Instability in the Athlete - Key Considerations for Rehabilitation.

The Latarjet procedure with transfer of the coracoid process and its attached conjoint tendon is a well-established surgical technique for the treatment of anterior glenohumeral instability in patients with anteroinferior bone loss and/or high risk for recurrence. Biomechanical and clinical studies have shown excellent results and high rates of return to sports. However, there is an absence of standardized, objective criteria to accurately assess an athlete's ability to progress through each phase of rehabilitation. Return to sports rehabilitation, progressed by quantitatively measured functional goals, may improve the athlete's integration back to sports participation. Therefore, the purpose of this clinical commentary is to provide a rehabilitation protocol for the Latarjet procedure, progressing through clearly defined phases, with guidance for safe and effective return to sport. Recommended criteria are highlighted which allows the clinician to progress the patient through each phase appropriately rather than purely following timeframes from surgery. This progression ensures the patient has completed a thorough rehabilitation program that addresses ROM, strength, power, neuromuscular control and a graded return to play. Level of Evidence: 5.

Effects of short-term graded dietary carbohydrate intake on intramuscular and whole body metabolism during moderate-intensity exercise.

Altering dietary carbohydrate (CHO) intake modulates fuel utilization during exercise. However, there has been no systematic evaluation of metabolic responses to graded changes in short-term (< 1 wk) dietary CHO intake. Thirteen active men performed interval running exercise combined with isocaloric diets over 3 days before evaluation of metabolic responses to 60-min running at 65% V̇O2max on three occasions. Diets contained lower [LOW, 2.40 ± 0.66 g CHO·kg-1·day-1, 21.3 ± 0.5% of energy intake (EI)], moderate (MOD, 4.98 ± 1.31 g CHO·kg-1·day-1, 46.3 ± 0.7% EI), or higher (HIGH, 6.48 ± 1.56 g CHO·kg-1·day-1, 60.5 ± 1.6% EI) CHO. Preexercise muscle glycogen content was lower in LOW [54.3 ± 26.4 mmol·kg-1 wet weight (ww)] compared with MOD (82.6 ± 18.8 mmol·kg -1 ww) and HIGH (80.4 ± 26.0 mmol·kg-1 ww, P < 0.001; MOD vs. HIGH, P = 0.85). Whole body substrate oxidation, systemic responses, and muscle substrate utilization during exercise indicated increased fat and decreased CHO metabolism in LOW [respiratory exchange ratio (RER): 0.81 ± 0.01] compared with MOD (RER 0.86 ± 0.01, P = 0.0005) and HIGH (RER: 0.88 ± 0.01, P < 0.0001; MOD vs. HIGH, P = 0.14). Higher basal muscle expression of genes encoding proteins implicated in fat utilization was observed in LOW. In conclusion, muscle glycogen availability and subsequent metabolic responses to exercise were resistant to increases in dietary CHO intake from ∼5.0 to ∼6.5 g CHO·kg-1·day-1 (46% to 61% EI), while muscle glycogen, gene expression, and metabolic responses were sensitive to more marked reductions in CHO intake (∼2.4 g CHO·kg-1·day-1, ∼21% EI).NEW & NOTEWORTHY The data presented here suggest that metabolic responses to steady-state aerobic exercise are somewhat resistant to short-term changes in dietary carbohydrate (CHO) intake within the 5-6.5 g CHO·kg-1·day-1 [46-61% energy intake (EI)] range. In contrast, reduction in short-term dietary CHO intake to ∼2.4 g CHO·kg-1·day-1 (21% EI) evoked clear changes indicative of increased fat and decreased CHO metabolism during exercise.

Lipid Metabolism Links Nutrient-Exercise Timing to Insulin Sensitivity in Men Classified as Overweight or Obese.

CONTEXT: Pre-exercise nutrient availability alters acute metabolic responses to exercise, which could modulate training responsiveness. OBJECTIVE: To assess acute and chronic effects of exercise performed before versus after nutrient ingestion on whole-body and intramuscular lipid utilization and postprandial glucose metabolism. DESIGN: (1) Acute, randomized, crossover design (Acute Study); (2) 6-week, randomized, controlled design (Training Study). SETTING: General community. PARTICIPANTS: Men with overweight/obesity (mean ± standard deviation, body mass index: 30.2 ± 3.5 kg⋅m-2 for Acute Study, 30.9 ± 4.5 kg⋅m-2 for Training Study). INTERVENTIONS: Moderate-intensity cycling performed before versus after mixed-macronutrient breakfast (Acute Study) or carbohydrate (Training Study) ingestion. RESULTS: Acute Study-exercise before versus after breakfast consumption increased net intramuscular lipid utilization in type I (net change: -3.44 ± 2.63% versus 1.44 ± 4.18% area lipid staining, P < 0.01) and type II fibers (-1.89 ± 2.48% versus 1.83 ± 1.92% area lipid staining, P < 0.05). Training Study-postprandial glycemia was not differentially affected by 6 weeks of exercise training performed before versus after carbohydrate intake (P > 0.05). However, postprandial insulinemia was reduced with exercise training performed before but not after carbohydrate ingestion (P = 0.03). This resulted in increased oral glucose insulin sensitivity (25 ± 38 vs -21 ± 32 mL⋅min-1⋅m-2; P = 0.01), associated with increased lipid utilization during exercise (r = 0.50, P = 0.02). Regular exercise before nutrient provision also augmented remodeling of skeletal muscle phospholipids and protein content of the glucose transport protein GLUT4 (P < 0.05). CONCLUSIONS: Experiments investigating exercise training and metabolic health should consider nutrient-exercise timing, and exercise performed before versus after nutrient intake (ie, in the fasted state) may exert beneficial effects on lipid utilization and reduce postprandial insulinemia.

REHABILITATION FOLLOWING SUBSCAPULARIS TENDON REPAIR.

Subscapularis (SSC) tendon tears are less common than tears of the remaining rotator cuff tendons, but one with serious consequences given its function as one of the main internal rotators and anterior stabilizers. Mild fraying involving the upper third of the tendon can be treated non-operatively; however, more substantive tears usually require repair in cases of pain or functional impairment. Given the importance of the subscapularis tendon in maintaining stability of the glenohumeral joint and performing internal rotation of the arm, surgical intervention with emphasis on repair may be recommended to eliminate pain and restore strength. Postoperative rehabilitation through phased progression is utilized to avoid premature stress on the healing tissue while enabling early return to daily activities. The purpose of this clinical commentary is to provide an evidence-based description of postoperative rehabilitation following SSC tendon repair with guidance for safe and effective return to activity and sports. LEVEL OF EVIDENCE: 5.

Identification of key residues coordinating functional inhibition of P2X7 receptors by zinc and copper.

P2X(7) receptors are distinct from other ATP-gated P2X receptors in that they are potently inhibited by submicromolar concentrations of zinc and copper. The molecular basis for the strong functional inhibition by zinc and copper at this purinergic ionotropic receptor is controversial. We hypothesized that it involves a direct interaction of zinc and copper with residues in the ectodomain of the P2X(7) receptor. Fourteen potential metal interacting residues are conserved in the ectodomain of all mammalian P2X(7) receptors, none of which is homologous to previously identified sites in other P2X receptors shown to be important for functional potentiation by zinc. We introduced alanine substitutions into each of these residues, expressed wild-type and mutated receptors in human embryonic kidney 293 cells, and recorded resulting ATP and BzATP-evoked membrane currents. Agonist concentration-response curves were similar for all 12 functional mutant receptors. Alanine substitution at His(62) or Asp(197) strongly attenuated both zinc and copper inhibition, and the double mutant [H62A/D197A] mutant receptor was virtually insensitive to inhibition by zinc or copper. Thus, we conclude that zinc and copper inhibition is due to a direct interaction of these divalent cations with ectodomain residues of the P2X(7) receptor, primarily involving combined interaction with His(62) and Asp(197) residues.

A case report of the use of nanocrystalline silver dressing in the management of acute surgical site wound infected with MRSA to prevent cutaneous necrosis following revision surgery.

The authors report the use of nanocrystalline silver (Acticoat 7, Smith and Nephew, London, UK) in an acute surgical wound to prevent localized skin necrosis due to infection, thereby avoiding skin grafting as a secondary procedure. Two patients were successfully treated with Acticoat 7 dressings without using systemic antimicrobials after developing methicillin-resistant Staphylococcus aureus infection in the surgical site. Despite a history of smoking and incision through scar tissues, the wound did not progress into deep infection nor was there recurrence of infection at 2 years follow-up. The intention was to use this particular dressing to assess the effect of silver on infected keratinocytes in an acute wound environment. It is possible that the use of Acticoat 7 may reduce the bacterial loading at the wound site, thereby decreasing a propensity for skin necrosis caused by the infective process. This case report demonstrates that the acute surgical wound with impending cutaneous necrosis due to localized infection may be treated without oral antimicrobials.

Acute lymphoblastic leukaemia cells produce large extracellular vesicles containing organelles and an active cytoskeleton.

Extracellular vesicles have been described in non-paracrine cellular interactions in cancer. We report a similar phenomenon in B-cell precursor (BCP) acute lymphoblastic leukaemia (ALL). Using advanced microscopy and high throughput screening, we further characterise a subset of large vesicles (LEVs) identified in cell lines, murine models of human BCP-ALL and clinical samples. Primary ALL blasts and cell lines released heterogeneous anucleate vesicles <6 micron into extracellular fluids. Larger LEVs were enclosed in continuous membranes, contained intact organelles and demonstrated an organised cytoskeleton. An excess of circulating CD19-positive LEVs were observed in diagnostic samples and isolated from mice engrafted with BCP-ALL primary cells. LEVs exhibited dynamic shape change in vitro and were internalised by other leukaemic cell lines leading to phenotypic transformation analogous to the cell of origin. In patient-derived xenografts, LEVs were released by primary ALL cells into extracellular spaces and internalised by murine mesenchymal cells in vivo. Collectively these data highlight the heterogeneity but accessibility of LEVs in clinical samples and their potential to provide a unique insight into the biology of the cell of origin and to their development as novel biomarkers to aid diagnosis and improve therapeutic outcomes.

Management of a difficult-to-heal chronic wound infected with methycillin-resistant staphylococcus aureus in a patient with psoriasis following a complex knee surgery.

This report presents the difficulties encountered in managing a wound colonized with methycillin-resistant Staphylococcus aureus (MRSA) following a complex knee surgery in an elderly female patient with generalized psoriasis. The patient's chronic wound was successfully treated with nanocrystalline silver-releasing dressings (Acticoat). The patient did not develop a deep-seated infection, nor was removal of the implant needed. However, the wound infection persisted for 6 months. At 3 years follow-up, the patient has satisfactory skin over the implant on the knee.

Immunofluorescence microscopy of SNAP23 in human skeletal muscle reveals colocalization with plasma membrane, lipid droplets, and mitochondria.

Synaptosomal-associated protein 23 (SNAP23) is a SNARE protein expressed abundantly in human skeletal muscle. Its established role is to mediate insulin-stimulated docking and fusion of glucose transporter 4 (GLUT4) with the plasma membrane. Recent in vitro research has proposed that SNAP23 may also play a role in the fusion of growing lipid droplets (LDs) and the channeling of LD-derived fatty acids (FAs) into neighboring mitochondria for ß-oxidation. This study investigates the subcellular distribution of SNAP23 in human skeletal muscle using immunofluorescence microscopy to confirm that SNAP23 localization supports the three proposed metabolic roles. Percutaneous biopsies were obtained from the m. vastus lateralis of six lean, healthy males in the rested, overnight fasted state. Cryosections were stained with antibodies targeting SNAP23, the mitochondrial marker cytochrome c oxidase and the plasma membrane marker dystrophin, whereas intramuscular LDs were stained using the neutral lipid dye oil red O. SNAP23 displayed areas of intense punctate staining in the intracellular regions of all muscle fibers and continuous intense staining in peripheral regions of the cell. Quantitation of confocal microscopy images showed colocalization of SNAP23 with the plasma membrane marker dystrophin (Pearson's correlation coefficient r = 0.50 ± 0.01). The intense punctate intracellular staining colocalized primarily with the mitochondrial marker cytochrome C oxidase (r = 0.50 ± 0.012) and to a lesser extent with LDs (r = 0.21 ± 0.01) visualized with oil red O. We conclude that the observed subcellular distribution of SNAP23 in human skeletal muscle supports the three aforementioned metabolic roles.