The ototoxic drug cisplatin localises to stress granules altering their dynamics and composition.

Cisplatin is an effective platinum-based chemotherapeutic with several side effects, including ototoxicity. Cochlear cells have low rates of proliferation yet are highly susceptible to cisplatin. We hypothesised that cisplatin ototoxicity might be caused by cisplatin-protein interactions rather than cisplatin-DNA interactions. Two known cisplatin-binding proteins are involved in the stress granule (SG) response. SGs are a pro-survival mechanism involving formation of transient ribonucleoprotein complexes during stress. We examined the effects of cisplatin on SG dynamics and composition in cell lines derived from the cochlea and retinal pigment epithelium. Cisplatin-induced SGs are significantly diminished in size and quantity compared to arsenite-induced SGs and are persistent after 24 h recovery. Additionally, cisplatin pre-treated cells were unable to form a typical SG response to subsequent arsenite stress. Cisplatin-induced SGs had significant reductions in the sequestration of eIF4G and the proteins RACK1 and DDX3X. Live-cell imaging of Texas Red-conjugated cisplatin revealed its localisation to SGs and retention for at least 24 h. We show cisplatin-induced SGs have impaired assembly, altered composition and are persistent, providing evidence of an alternate mechanism for cisplatin-induced ototoxicity via an impaired SG response.

B Lymphocyte-Derived CCL7 Augments Neutrophil and Monocyte Recruitment, Exacerbating Acute Kidney Injury.

Acute kidney injury (AKI) is a serious condition affecting one fifth of hospital inpatients. B lymphocytes have immunological functions beyond Ab production and may produce cytokines and chemokines that modulate inflammation. In this study, we investigated leukocyte responses in a mouse model of AKI and observed an increase in circulating and kidney B cells, particularly a B220low subset, following AKI. We found that B cells produce the chemokine CCL7, with the potential to facilitate neutrophil and monocyte recruitment to the injured kidney. Siglec-G-deficient mice, which have increased numbers of B220low innate B cells and a lower B cell activation threshold, had increased Ccl7 transcripts, increased neutrophil and monocyte numbers in the kidney, and more severe AKI. CCL7 blockade in mice reduced myeloid cell infiltration into the kidney and ameliorated AKI. In two independent cohorts of human patients with AKI, we observed significantly higher CCL7 transcripts compared with controls, and in a third cohort, we observed an increase in urinary CCL7 levels in AKI, supporting the clinical importance of this pathway. Together, our data suggest that B cells contribute to early sterile inflammation in AKI via the production of leukocyte-recruiting chemokines.

Pilot study of a noninvasive real-time optical backscatter probe in liver transplantation.

Transplantation of severely steatotic donor livers is associated with early allograft dysfunction and poorer graft survival. Histology remains the gold standard diagnostic of donor steatosis despite the lack of consensus definition and its subjective nature. In this prospective observational study of liver transplant patients, we demonstrate the feasibility of using a handheld optical backscatter probe to assess the degree of hepatic steatosis and correlate the backscatter readings with clinical outcomes. The probe is placed on the surface of the liver and emits red and near infrared light from the tip of the device and measures the amount of backscatter of light from liver tissue via two photodiodes. Measurement of optical backscatter (Mantel-Cox P < 0.0001) and histopathological scoring of macrovesicular steatosis (Mantel-Cox P = 0.046) were predictive of 5-year graft survival. Recipients with early allograft dysfunction defined according to both Olthoff (P = 0.0067) and MEAF score (P = 0.0097) had significantly higher backscatter levels from the donor organ. Backscatter was predictive of graft loss (AUC 0.75, P = 0.0045). This study demonstrates the feasibility of real-time measurement of optical backscatter in donor livers. Early results indicate readings correlate with steatosis and may give insight to graft outcomes such as early allograft dysfunction and graft loss.

Allograft rejection is associated with development of functional IgE specific for donor MHC antigens.

BACKGROUND: Donor-specific antibodies of the IgG isotype are measured routinely for diagnostic purposes in renal transplant recipients and are associated with antibody-mediated rejection and long-term graft loss. OBJECTIVE: This study aimed to investigate whether MHC-specific antibodies of the IgE isotype are induced during allograft rejection. METHODS: Anti-MHC/HLA IgE levels were measured in sera of mice grafted with skin or heart transplants from various donor strains and in sera of kidney transplant patients with high levels of HLA IgG. Mediator release was triggered in vitro by stimulating basophils that were coated with murine or human IgE-positive serum, respectively, with specific recombinant MHC/HLA antigens. Kidney tissue samples obtained from organ donors were analyzed by using flow cytometry for cells expressing the high-affinity receptor for IgE (FcεRI). RESULTS: Donor MHC class I- and MHC class II-specific IgE was found on acute rejection of skin and heart grafts in several murine strain combinations, as well as during chronic antibody-mediated heart graft rejection. Anti-HLA IgE, including donor HLA class I and II specificities, was identified in a group of sensitized transplant recipients. Murine and human anti-MHC/HLA IgE triggered mediator release in coated basophils on stimulation with specific MHC/HLA antigens. HLA-specific IgE was not linked to atopy, and allergen-specific IgE present in allergic patients did not cross-react with HLA antigens. FcεRI+ cells were found in the human renal cortex and medulla and provide targets for HLA-specific IgE. CONCLUSION: These results demonstrate that MHC/HLA-specific IgE develops during an alloresponse and is functional in mediating effector mechanisms.

Mitochondrial mechanisms and therapeutics in ischaemia reperfusion injury.

Acute kidney injury (AKI) remains a major problem in critically unwell children and young adults. Ischaemia reperfusion (IR) injury is a major contributor to the development of AKI in a significant proportion of these cases and mitochondria are increasingly recognised as being central to this process through generation of a burst of reactive oxygen species early in reperfusion. Mitochondria have additionally been shown to have key roles in downstream processes including activation of the immune response, immunomodulation, and apoptosis and necrosis. The recognition of the central role of mitochondria in IR injury and an increased understanding of the pathophysiology that undermines these processes has resulted in identification of novel therapeutic targets and potential biomarkers. This review summarises a variety of therapeutic approaches that are currently under exploration and may have potential in ameliorating AKI in children in the future.

Assessment of H2S in vivo using the newly developed mitochondria-targeted mass spectrometry probe MitoA.

Hydrogen sulfide (H2S) is produced endogenously in vivo and has multiple effects on signaling pathways and cell function. Mitochondria can be both an H2S source and sink, and many of the biological effects of H2S relate to its interactions with mitochondria. However, the significance of mitochondrial H2S is uncertain, in part due to the difficulty of assessing changes in its concentration in vivo Although a number of fluorescent H2S probes have been developed these are best suited to cells in culture and cannot be used in vivo To address this unmet need we have developed a mitochondria-targeted H2S probe, MitoA, which can be used to assess relative changes in mitochondrial H2S levels in vivo MitoA comprises a lipophilic triphenylphosphonium (TPP) cation coupled to an aryl azide. The TPP cation leads to the accumulation of MitoA inside mitochondria within tissues in vivo There, the aryl azido group reacts with H2S to form an aryl amine (MitoN). The extent of conversion of MitoA to MitoN thus gives an indication of the levels of mitochondrial H2S in vivo Both compounds can be detected sensitively by liquid chromatography tandem mass spectrometry (LC-MS/MS) analysis of the tissues, and quantified relative to deuterated internal standards. Here we describe the synthesis and characterization of MitoA and show that it can be used to assess changes in mitochondrial H2S levels in vivo As a proof of principle we used MitoA to show that H2S levels increase in vivo during myocardial ischemia.

Science to Practice: Quantitative US Elastography Can Be Used to Quantify Mechanical and Histologic Tendon Healing in a Rabbit Model of Achilles Tendon Transection.

Compression-based ultrasonographic (US) elastography is associated with time-dependent mechanical and histologic changes of the healing tendon in a transected rabbit model of the Achilles tendon. This finding will lead to continued development of quantitative US, which can be used to objectively assess a diseased or healing tendon. With advances in the method used, clinical translation of tendon elastography may enable clinicians to diagnose tendon damage and track healing, which should improve both treatment and outcome.

Quantitative ultrasound mapping of regional variations in shear wave speeds of the aging Achilles tendon.

OBJECTIVES: Evaluate the effects of aging on healthy Achilles tendon and aponeurosis shear wave speed (SWS), a quantitative metric which reflects tissue elasticity. METHODS: Shear wave elastography was used to measure spatial variations in Achilles tendon SWS in healthy young (n = 15, 25 ± 4 years), middle-aged (n = 10, 49 ± 4 years) and older (n = 10, 68 ± 5 years) adults. SWS was separately measured in the free Achilles tendon, soleus aponeurosis and gastrocnemius aponeurosis in resting (R), stretched (dorsiflexed 15° from R) and slack (plantarflexed 15° from R) postures. RESULTS: SWS significantly increased with stretch and varied with age in all tendon regions. Slack free tendon SWS was significantly higher in older adults than young adults (p = 0.025). However, stretched soleus aponeurosis SWS was significantly lower in older adults than young adults (p = 0.01). Stretched gastrocnemius aponeurosis SWS was significantly lower in both middle-aged (p = 0.003) and older (p = 0.001) adults, relative to younger adults. CONCLUSION: These results suggest that aging alters spatial variations in Achilles tendon elasticity, which could alter deformations within the triceps surae muscle-tendon units, thus affecting injury potential. The observed location- and posture-dependent variations highlight the importance of controlling ankle posture and imaging location when using shear wave approaches clinically to evaluate tendon disorders. KEY POINTS: • Shear wave elastography shows promise as a clinical quantitative ultrasound-based technique. • Aging induces location-dependent changes in Achilles tendon shear wave speed. • Spatial and postural dependence necessitates careful integration of this approach clinically.

Assessing the quality of primary care referrals to surgery of patients with diabetes in the East of England: A multi-centre cross-sectional cohort study.

AIM: Peri-operative hyperglycaemia is associated with an increased incidence of adverse outcomes. Communication between primary and secondary care is paramount to minimise these harms. National guidance in the UK recommends that the glycated haemoglobin (HbA1c) should be measured within 3 months prior to surgery and that the concentration should be less that 69 mmol/mol (8.5%). In addition, national guidance outlines the minimum dataset that should be included in any letter at the time of referral to the surgeons. Currently, it is unclear how well this process is being carried out. This study investigated the quality of information being handed over during the referral from primary care to surgical outpatients within the East of England. METHODS: Primary care referrals to nine different NHS hospital Trusts were gathered over a 1-week period. All age groups were included from 11 different surgical specialties. Referral letters were analysed using a standardised data collection tool based on the national guidelines. RESULTS: A total of 1919 referrals were received, of whom 169 (8.8%) had previously diagnosed diabetes mellitus (DM). However, of these, 38 made no mention of DM in the referral letter but were on glucose-lowering agents. Only 13 (7.7%) referrals for patients with DM contained a recent HbA1c, and 20 (11.8%) contained no documentation of glucose-lowering medication. CONCLUSION: This study has shown that the quality of referral letters to surgical specialties for patients with DM in the East of England remain inadequate. There is a clear need for improving the quality of clinical data contained within referral letters from primary care. In addition, we have shown that the rate of referral for surgery for people with diabetes is almost 50% higher than the background population with diabetes.

Achilles Tendon Loading during Running Estimated Via Shear Wave Tensiometry: A Step Toward Wearable Kinetic Analysis.

PURPOSE: Understanding muscle-tendon forces (e.g., triceps surae and Achilles tendon) during locomotion may aid in the assessment of human performance, injury risk, and rehabilitation progress. Shear wave tensiometry is a noninvasive technique for assessing in vivo tendon forces that has been recently adapted to a wearable technology. However, previous laboratory-based and outdoor tensiometry studies have not evaluated running. This study was undertaken to assess the capacity for shear wave tensiometry to produce valid measures of Achilles tendon loading during running at a range of speeds. METHODS: Participants walked (1.34 m·s -1 ) and ran (2.68, 3.35, and 4.47 m·s -1 ) on an instrumented treadmill while shear wave tensiometers recorded Achilles tendon wave speeds simultaneously with whole-body kinematic and ground reaction force data. A simple isometric task allowed for the participant-specific conversion of Achilles tendon wave speeds to forces. Achilles tendon forces were compared with ankle torque measures obtained independently via inverse dynamics analyses. Differences in Achilles tendon wave speed, Achilles tendon force, and ankle torque across walking and running speeds were analyzed with linear mixed-effects models. RESULTS: Achilles tendon wave speed, Achilles tendon force, and ankle torque exhibited similar temporal patterns across the stance phase of walking and running. Significant monotonic increases in peak Achilles tendon wave speed (56.0-83.8 m·s -1 ), Achilles tendon force (44.0-98.7 N·kg -1 ), and ankle torque (1.72-3.68 N·m·(kg -1 )) were observed with increasing locomotion speed (1.34-4.47 m·s -1 ). Tensiometry estimates of peak Achilles tendon force during running (8.2-10.1 body weights) were within the range of those estimated previously via indirect methods. CONCLUSIONS: These results set the stage for using tensiometry to evaluate Achilles tendon loading during unobstructed athletic movements, such as running, performed in the field.

Reducing alcohol harms whilst minimising impact on hospitality businesses: 'Sweetspot' policy options.

BACKGROUND: During COVID-19, hospitality businesses (e.g. bars, restaurants) were closed/restricted whilst off-sales of alcohol increased, with health consequences. Post-covid, governments face lobbying to support such businesses, but many health services remain under pressure. We appraised 'sweetspot' policy options: those with potential to benefit public services and health, whilst avoiding or minimising negative impact on the hospitality sector. METHODS: We conducted rapid non-systematic evidence reviews using index papers, citation searches and team knowledge to summarise the literature relating to four possible 'sweetspot' policy areas: pricing interventions (9 systematic reviews (SR); 14 papers/reports); regulation of online sales (1 SR; 1 paper); place-shaping (2 SRs; 18 papers/reports); and violence reduction initiatives (9 SRs; 24 papers/reports); and led two expert workshops (n = 11). RESULTS: Interventions that raise the price of cheaper shop-bought alcohol appear promising as 'sweetspot' policies; any impact on hospitality is likely small and potentially positive. Restrictions on online sales such as speed or timing of delivery may reduce harm and diversion of consumption from on-trade to home settings. Place-shaping is not well-supported by evidence and experts were sceptical. Reduced late-night trading hours likely reduce violence; evidence of impact on hospitality is scant. Other violence reduction initiatives may modestly reduce harms whilst supporting hospitality, but require resources to deliver multiple measures simultaneously in partnership. CONCLUSIONS: Available evidence and expert views point to regulation of pricing and online sales as having greatest potential as 'sweetspot' alcohol policies, reducing alcohol harm whilst minimising negative impact on hospitality businesses.

Localized Liver Injury During Normothermic Ex Situ Liver Perfusion Has No Impact on Short-term Liver Transplant Outcomes.

BACKGROUND: Normothermic ex situ liver perfusion (NESLiP) has the potential to increase organ utilization. Radiological evidence of localized liver injury due to compression at the time of NESLiP, termed cradle compression, is a recognized phenomenon but is poorly characterized. METHODS: A retrospective analysis of a prospectively collected database was performed of transplanted livers that underwent NESLiP and subsequently had a computed tomography performed within the first 14 d posttransplant. The primary study outcome was 1-y graft survival. RESULTS: Seventy livers (63%) were included in the analysis. Radiological evidence of cradle compression was observed in 21 of 70 (30%). There was no difference in rate of cradle compression between donor after circulatory death and donated after brain death donors ( P  = 0.37) or with duration of NESLiP. Univariate analysis demonstrated younger (area under the receiver operating characteristic, 0.68; P = 0.008; 95% confidence interval [CI], 0.55-0.82) and heavier (area under the receiver operating characteristic, 0.80; P  < 0.001; 95% CI, 0.69-0.91) livers to be at risk of cradle compression. Only liver weight was associated with cradle compression on multivariate analysis (odds ratio, 1.003; P  = 0.005; 95% CI, 1.001-1.005). There was no difference in 1-y graft survival (16/17 [94.1%] versus 44/48 [91.6%]; odds ratio, 0.69; P  = 0.75; 95% CI, 0.07-6.62). CONCLUSIONS: This is the first study assessing the impact of cradle compression on outcome. We have identified increased donor liver weight and younger age as risk factors for the development of this phenomenon. Increasing utilization of NESLiP will result in the increased incidence of cradle compression but the apparent absence of long-term sequelae is reassuring. Routine postoperative axial imaging may be warranted.

Long-term results of plaque excision combined with aggressive pharmacotherapy in high-risk patients with advanced peripheral artery disease (SAVE a LEG registry).

BACKGROUND: In United States alone there are more than 12 million people with peripheral artery disease (PAD). Long-term outcomes of plaque excision in high-risk population (patients with diabetes and patients with end stage renal disease on dialysis) are scarce. METHODS: Since November 2003, we treated 225 consecutive patients (138 male, mean age: 66.3 ± 12.4, range: 29-93) with SilverHawk(TM) plaque excision for critical limb ischemia or disabling claudication. A total of 367 procedures were performed treating 832 lesions (157 restenotic, 675 de novo). One hundred fifty-five patients (68.9%) were diabetics, 74 (32.9%) were on dialysis. All patients were treated with statins, clopidogrel, aspirin, and aggressive glycemic control. The primary endpoint for our study was target lesion revascularization (TLR), and the secondary endpoint was an assessment of major adverse events (all cause death, amputation, TLR). RESULTS: The average time of observation was 2.2 ± 1.2 years. Procedural success rate was 99.4% with <30% residual stenosis achieved in 818 (98.9%) lesions. SilverHawk was used alone in 86.7%. No acute limb loss or major perforation occurred. Sixty (26.6%) patients had TLR. Long-term mortality was 16.4%. Seven (3.1%) patients had to undergo major amputations and 7 (3.1%) minor amputations. Seventy (31.1%) patients had a major adverse event. Atorvastatin 80 mg was found to be independent predictor of survival, and major amputation was found to be independent predictor of mortality. CONCLUSIONS: SilverHawk Plaque Excision combined with aggressive pharmacotherapy in this presented high-risk population is associated with promising long-term outcomes that compare favorably with accepted standards of care.

The "backbone" of stigma: identifying the global core of public prejudice associated with mental illness.

OBJECTIVES: We used the Stigma in Global Context-Mental Health Study to assess the core sentiments that represent consistent, salient public health intervention targets. METHODS: Data from 16 countries employed a nationally representative sampling strategy, international collaboration for instrument development, and case vignettes with Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition depression and schizophrenia criteria. We measured knowledge and prejudice with existing questions and scales, and employed exploratory data analysis to examine the public response to 43 items. RESULTS: Across countries, levels of recognition, acceptance of neurobiological attributions, and treatment endorsement were high. However, a core of 5 prejudice items was consistently high, even in countries with low overall stigma levels. The levels were generally lower for depression than schizophrenia, and exclusionary sentiments for more intimate venues and in authority-based roles showed the greatest stigma. Negative responses to schizophrenia and depression were highly correlated across countries. CONCLUSIONS: These results challenge researchers to reconfigure measurement strategies and policymakers to reconsider efforts to improve population mental health. Efforts should prioritize inclusion, integration, and competences for the reduction of cultural barriers to recognition, response, and recovery.

Persistent mortality and heart failure burden of anterior ST-segment elevation myocardial infarction following primary percutaneous coronary intervention: real-world evidence from the US Medicare Data Set.

OBJECTIVES: We sought to compare the temporal trends in the incidence of death and rehospitalisation for congestive heart failure (CHF) following anterior ST-elevation myocardial infarction (STEMI) in a Medicare cohort of beneficiaries treated with primary percutaneous coronary intervention (PCI) in 2005 (n=1479) with those treated in 2016 through quarter (Q) 2 of 2017 (n=22 432). DESIGN: This retrospective analysis examined outcomes using both descriptive and regression analysis to control for differences in patient clinical characteristics over time. PRIMARY OUTCOME MEASURES: The primary outcomes are 1 year and 2 year rates of mortality and re-hospitalisation for CHF. RESULTS: The 1 year mortality rate was numerically higher in the 2016 cohort at 10.3% (95% CI 9.9 to 10.7) versus 8.9% (CI 7.4 to 10.3; p=0.068). The 2 year mortality rate was significantly higher in the 2016 cohort at 14.5% (CI 13.9 to 15.1) versus 11.4% (CI 9.2 to 13.6; p<0.01). The 1 year rehospitalisation for CHF was lower in the 2016 cohort at 10.6% (CI 10.0 to 11.2) versus 16.7% (CI 14.0 to 19.4; p<0.001), but the 2 year rate was not significantly different at 19.3% (CI 17.7 to 20.9) versus 20.7% (CI 16.4 to 24.9; p=0.55). After adjustment for covariates with two models, the 1 year mortality increased by 2.3% (CI 0.8 to 3.7; p<0.01) and 4.1% (CI 2.6 to 5.6; p<0.001) in the 2016 cohort. The 2 year adjusted mortality also increased by 4.2% (CI 2.0 to 6.4; p<0.001) and 6.5% (CI 4.2 to 8.7; p<0.001) in the 2016 cohort. The risk adjusted trends for rehospitalisation for CHF were similar to the unadjusted findings. CONCLUSIONS: Despite prior improvements in STEMI outcomes in the reperfusion era related to the broad adoption of timely PCI, there is a persistent high mortality and CHF burden in Medicare beneficiaries with anterior STEMI. New strategies that address reperfusion injury and enhance myocardial salvage are needed.

A trained neural network model accurately predicts Achilles tendon stress during walking and running based on shear wave propagation.

Shear wave tensiometry is a noninvasive technique for measuring tendon loading during activity based on the speed of a shear wave traveling along the tendon. Shear wave speed has been shown to modulate with axial stress, but calibration is required to obtain absolute measures of tendon loading. However, the current technique only makes use of wave speed, whereas other characteristics of the wave (e.g., amplitude, frequency content) may also vary with tendon loading. It is possible that these data could be used in addition to wave speed to circumvent the need for calibration. Given the potential complex relationships to tendon loading, and the lack of an analytical model to guide the use of these data, it is sensible to use a machine learning approach. Here, we used an ensemble neural network approach to predict inverse dynamics estimates of Achilles tendon stress from shear wave tensiometry data collected in a prior study. Neural network-predicted stresses were highly correlated with stance phase inverse dynamics estimates for walking (R2 = 0.89 ± 0.06) and running (R2 = 0.87 ± 0.11) data reserved for neural network model testing and not included in model training. Additionally, error between neural network-predicted and inverse dynamics-estimated stress was reasonable (walking: RMSD = 11 ± 2% of peak load; running: 25 ± 14%). Results of this pilot analysis suggest that a machine learning approach could reduce the reliance of shear wave tensiometry on calibration and expand its usability in many settings.

A hierarchical clustering approach for examining the relationship between pelvis-proximal femur geometry and bone stress injury in runners.

Bone stress injury (BSI) risk in runners is multifactorial and not well understood. Unsupervised machine learning approaches can potentially elucidate risk factors for BSI by identifying groups of similar runners within a population which differ in BSI incidence. Here, a hierarchical clustering approach is used to identify groups of collegiate cross country runners based on 2-dimensional frontal plane pelvis and proximal femur geometry, which was extracted from dual-energy X-ray absorptiometry scans and dimensionally reduced by principal component analysis. Seven distinct groups were identified using the cluster tree, with the initial split being highly related to female-male differences. Visual inspection revealed clear differences between groups in pelvis and proximal femur geometry, and groups were found to differ in lower body BSI incidence during the subsequent academic year (Rand index = 0.53; adjusted Rand index = 0.07). Linear models showed between-cluster differences in visually identified geometric measures. Geometric measures were aggregated into a pelvis shape factor based on trends with BSI incidence, and the resulting shape factor was significantly different between clusters (p < 0.001). Lower shape factor values, corresponding with lower pelvis height and ischial span, and greater iliac span and trochanteric span, appeared to be related to increased BSI incidence. This trend was dominated by the effect observed across clusters of male runners, indicating that geometric effects may be more relevant to BSI risk in males, or that other factors masked the relationship in females. More broadly, this work outlines a methodological approach for distilling complex geometric differences into simple metrics that relate to injury risk.

American Society of Biomechanics Clinical Biomechanics Award 2021: Redistribution of muscle-tendon work in children with cerebral palsy who walk in crouch.

BACKGROUND: Previous study showed the triceps surae exhibits spring-like behavior about the ankle during walking in children with cerebral palsy. Thus, the work generated by the triceps surae is diminished relative to typically developing children. This study investigated whether the quadriceps offset the lack of triceps surae work production in children with cerebral palsy who walk in crouch. METHODS: Seven children with cerebral palsy (8-16 yrs) and 14 typically developing controls (8-17 yrs) walked overground at their preferred speed in a motion analysis laboratory. Shear wave tensiometers were used to track patellar and Achilles tendon loading throughout the gait cycle. Tendon force measures were coupled with muscle-tendon kinematic estimates to characterize the net work generated by the quadriceps and triceps surae about the knee and ankle, respectively. FINDINGS: Children with cerebral palsy generated significantly less triceps surae work when compared to controls (P < 0.001). The reverse was true at the knee. Children with cerebral palsy generated positive net work from the quadriceps about the knee, which exceeded the net quadriceps work generated by controls (P = 0.028). INTERPRETATION: There was a marked difference in functional behavior of the triceps surae and quadriceps in children with cerebral palsy who walk in crouch. In particular, the triceps surae of children with cerebral palsy exhibited spring-like behavior about the ankle while the quadriceps exhibited more motor-like behavior about the knee. This redistribution in work could partly be associated with the elevated energetic cost of walking in children with cerebral palsy and is relevant to consider when planning treatments to correct crouch gait.

Surgical outcomes of gallbladder cancer: the OMEGA retrospective, multicentre, international cohort study.

Background: Gallbladder cancer (GBC) is rare but aggressive. The extent of surgical intervention for different GBC stages is non-uniform, ranging from cholecystectomy alone to extended resections including major hepatectomy, resection of adjacent organs and routine extrahepatic bile duct resection (EBDR). Robust evidence here is lacking, however, and survival benefit poorly defined. This study assesses factors associated with recurrence-free survival (RFS), overall survival (OS) and morbidity and mortality following GBC surgery in high income countries (HIC) and low and middle income countries (LMIC). Methods: The multicentre, retrospective Operative Management of Gallbladder Cancer (OMEGA) cohort study included all patients who underwent GBC resection across 133 centres between 1st January 2010 and 31st December 2020. Regression analyses assessed factors associated with OS, RFS and morbidity. Findings: On multivariable analysis of all 3676 patients, wedge resection and segment IVb/V resection failed to improve RFS (HR 1.04 [0.84-1.29], p = 0.711 and HR 1.18 [0.95-1.46], p = 0.13 respectively) or OS (HR 0.96 [0.79-1.17], p = 0.67 and HR 1.48 [1.16-1.88], p = 0.49 respectively), while major hepatectomy was associated with worse RFS (HR 1.33 [1.02-1.74], p = 0.037) and OS (HR 1.26 [1.03-1.53], p = 0.022). Furthermore, EBDR (OR 2.86 [2.3-3.52], p < 0.0010), resection of additional organs (OR 2.22 [1.62-3.02], p < 0.0010) and major hepatectomy (OR 3.81 [2.55-5.73], p < 0.0010) were all associated with increased morbidity and mortality. Compared to LMIC, patients in HIC were associated with poorer RFS (HR 1.18 [1.02-1.37], p = 0.031) but not OS (HR 1.05 [0.91-1.22], p = 0.48). Adjuvant and neoadjuvant treatments were infrequently used. Interpretation: In this large, multicentre analysis of GBC surgical outcomes, liver resection was not conclusively associated with improved survival, and extended resections were associated with greater morbidity and mortality without oncological benefit. Aggressive upfront resections do not benefit higher stage GBC, and international collaborations are needed to develop evidence-based neoadjuvant and adjuvant treatment strategies to minimise surgical morbidity and prioritise prognostic benefit. Funding: Cambridge Hepatopancreatobiliary Department Research Fund.

Assessment of left ventricular tissue mitochondrial bioenergetics in patients with stable coronary artery disease.

Recurrent myocardial ischemia can lead to left ventricular (LV) dysfunction in patients with coronary artery disease (CAD). In this observational cohort study, we assessed for chronic metabolomic and transcriptomic adaptations within LV myocardium of patients undergoing coronary artery bypass grafting. During surgery, paired transmural LV biopsies were acquired on the beating heart from regions with and without evidence of inducible ischemia on preoperative stress perfusion cardiovascular magnetic resonance. From 33 patients, 63 biopsies were acquired, compared to analysis of LV samples from 11 donor hearts. The global myocardial adenosine triphosphate (ATP):adenosine diphosphate (ADP) ratio was reduced in patients with CAD as compared to donor LV tissue, with increased expression of oxidative phosphorylation (OXPHOS) genes encoding the electron transport chain complexes across multiple cell types. Paired analyses of biopsies obtained from LV segments with or without inducible ischemia revealed no significant difference in the ATP:ADP ratio, broader metabolic profile or expression of ventricular cardiomyocyte genes implicated in OXPHOS. Differential metabolite analysis suggested dysregulation of several intermediates in patients with reduced LV ejection fraction, including succinate. Overall, our results suggest that viable myocardium in patients with stable CAD has global alterations in bioenergetic and transcriptional profile without large regional differences between areas with or without inducible ischemia.