Volatile capture technology in sustainable anaesthetic practice: a narrative review

Anaesthetic practice contributes to climate change. Volatile capture technology, typically based on adsorption to a carbon- or silica-based substrate, has the potential to mitigate some of the harmful effects of using halogenated hydrocarbons. Anaesthetists have a professional responsibility to use anaesthetic agents which offer the greatest safety and clinical benefit with the lowest financial cost and environmental impacts. Inhalational anaesthetics should be used at an appropriate concentration with a minimal fresh gas flow via a circle system to minimise unnecessary waste. Once practice efficiencies have been maximised, only then should technical solutions such as volatile capture be employed. In this narrative review, we focus on the available literature relating to volatile capture technology, obtained via a targeted literature search and through contacting manufacturers and researchers. We found six studies focusing on the Blue-Zone Technologies Deltasorb®, SageTech Medical SID and Baxter/ZeoSys CONTRAfluran™ volatile capture systems. Though laboratory analyses of available systems suggest that > 95% in vitro mass transfer is possible for all three systems, the in vivo results for capture efficiency vary from 25% to 73%. Currently, there is no financial incentive for healthcare organisations to capture waste anaesthetic gases, and so the value of volatile capture technology requires quantification. System-level organisations, such as Greener NHS, are best positioned to commission such evaluations and make policy decisions to guide investment. Further research using volatile capture technology in real-world settings is necessary and we highlight some priority research questions to improve our understanding of the utility of this group of technologies.

A radiologist's guide to median sternotomy

Median sternotomy is widely recognised as the primary incision technique in cardiac surgery. This surgical procedure involves dividing the sternum to gain access to the heart and lungs, making it invaluable in correcting congenital heart defects. Furthermore, it is frequently employed in adult patients, particularly during coronary artery bypass graft (CABG) procedures. In this imaging review, we present a comprehensive overview of the pre-procedural assessment and various post-sternotomy complications encountered within our clinical experience at a tertiary cardiothoracic centre. The focus of this review is to outline the imaging features associated with mediastinal adhesions and establish the minimal safe distance between the sternum and common mediastinal structures when considering re-sternotomy. By providing visual examples, we aim to facilitate a better understanding of these key concepts. Moreover, we delve into a detailed discussion of a spectrum of postoperative complications that may arise following median sternotomy including those related to metalwork (sternal wire fracture), bone (sternal dehiscence, non-union and osteomyelitis), and soft tissue (abscess, haematoma).

Defining the proteomic landscape of cultured macrophages and their polarization continuum

Macrophages have previously been characterized based on phenotypical and functional differences into suggested simplified subtypes of MØ, M1, M2a and M2c. These macrophage subtypes can be generated in a well-established primary monocyte culture model that produces cells expressing accepted subtype surface markers. To determine how these subtypes retain functional similarities and better understand their formation, we generated all four subtypes from the same donors. Comparative whole-cell proteomics confirmed that four distinct macrophage subtypes could be induced from the same donor material, with > 50% of 5435 identified proteins being significantly altered in abundance between subtypes. Functional assessment highlighted that these distinct protein expression profiles are primed to enable specific cell functions, indicating that this shifting proteome is predictive of meaningful changes in cell characteristics. Importantly, the 2552 proteins remained consistent in abundance across all macrophage subtypes examined, demonstrating maintenance of a stable core proteome that likely enables swift polarity changes. We next explored the cross-polarization capabilities of preactivated M1 macrophages treated with dexamethasone. Importantly, these treated cells undergo a partial repolarization toward the M2c surface markers but still retain the M1 functional phenotype. Our investigation of polarized macrophage subtypes therefore provides evidence of a sliding scale of macrophage functionality, with these data sets providing a valuable benchmark resource for further studies of macrophage polarity, with relevance for cell therapy development and drug discovery.

Childhood cancer incidence & survival in Aotearoa, New Zealand 2010-2019

OBJECTIVE

To provide updated estimates of childhood cancer incidence and survival in Aotearoa, New Zealand.

METHOD

Registrations for children under the age of 15 years diagnosed with cancer between 2010 and 2019 were extracted from the New Zealand Children's Cancer Registry. Cases were stratified by age, sex, prioritised ethnicity (Māori, Pacific peoples, and non-Māori) and cancer type. Age-standardised incidence rates (ASRs) per million person years and observed survival rates were calculated.

RESULTS

During the study period, 1522 children were diagnosed with cancer providing an ASR of 169.1 per million per year (95 % Confidence Interval, CI: 157.0-181.2). For all childhood cancers combined, survival at 5-years was 85.6 % (95 % CI 83.7-87.3). There was a gap in 5-year survival between Māori (80.9 %, 95 % CI 76.5-84.6), Pacific peoples (82.6 %, 95 % CI 75.6-87,7) and Non-Māori (87.8 %, 95 % CI 85.6-89.7) In both adjusted and unadjusted models, this difference in survival was most marked (p < 0.05) among children who were 10-14 years of age at diagnosis.

CONCLUSION

Childhood cancer incidence and survival rates in Aotearoa, New Zealand remain comparable to other high-income countries. Further research is required to understand the survival difference between ethnic groups.

Adult neurogenesis does not explain the extensive post-eclosion growth of Heliconius mushroom bodies

Among butterflies, Heliconius have a unique behavioural profile, being the sole genus to actively feed on pollen. Heliconius learn the location of pollen resources, and have enhanced visual memories and expanded mushroom bodies, an insect learning and memory centre, relative to related genera. These structures also show extensive post-eclosion growth and developmental sensitivity to environmental conditions. However, whether this reflects plasticity in neurite growth, or an extension of neurogenesis into the adult stage, is unknown. Adult neurogenesis has been described in some Lepidoptera, and could provide one route to the increased neuron number observed in Heliconius. Here, we compare volumetric changes in the mushroom bodies of freshly eclosed and aged Heliconius erato and Dryas iulia, and estimate the number of intrinsic mushroom body neurons using a new and validated automated method to count nuclei. Despite extensive volumetric variation associated with age, our data show that neuron number is remarkably constant in both species, suggesting a lack of adult neurogenesis in the mushroom bodies. We support this conclusion with assays of mitotic cells, which reveal very low levels of post-eclosion cell division. Our analyses provide an insight into the evolution of neural plasticity, and can serve as a basis for continued exploration of the potential mechanisms behind brain development and maturation.

Longitudinal changes in white matter as measured with diffusion tensor imaging in adult-onset myotonic dystrophy type 1

Myotonic dystrophy type 1 is characterized by neuromuscular degeneration. Our objective was to compare change in white matter microstructure (fractional anisotropy, radial and axial diffusivity), and functional/clinical measures. Participants underwent yearly neuroimaging and neurocognitive assessments over three-years. Assessments encompassed full-scale intelligence, memory, language, visuospatial skills, attention, processing speed, and executive function, as well as clinical symptoms of muscle/motor function, apathy, and hypersomnolence. Mixed effects models were used to examine differences. 69 healthy adults (66.2% women) and 41 DM1 patients (70.7% women) provided 156 and 90 observations, respectively. There was a group by elapsed time interaction for cerebral white matter, where DM1 patients exhibited declines in white matter (all p<0.05). Likewise, DM1 patients either declined (motor), improved more slowly (intelligence), or remained stable (executive function) for functional outcomes. White matter was associated with functional performance; intelligence was predicted by axial (r = 0.832; p<0.01) and radial diffusivity (r = 0.291, p<0.05), and executive function was associated with anisotropy (r = 0.416, p<0.001), and diffusivity (axial: r = 0.237, p = 0.05 and radial: r = 0.300, p<0.05). Indices of white matter health are sensitive to progression in DM1. These results are important for clinical trial design, which utilize short intervals to establish treatment efficacy.

Chromogranin B (CHGB) is dimorphic and responsible for dominant anion channels delivered to cell surface via regulated secretion

Regulated secretion is conserved in all eukaryotes. In vertebrates granin family proteins function in all key steps of regulated secretion. Phase separation and amyloid-based storage of proteins and small molecules in secretory granules require ion homeostasis to maintain their steady states, and thus need ion conductances in granule membranes. But granular ion channels are still elusive. Here we show that granule exocytosis in neuroendocrine cells delivers to cell surface dominant anion channels, to which chromogranin B (CHGB) is critical. Biochemical fractionation shows that native CHGB distributes nearly equally in soluble and membrane-bound forms, and both reconstitute highly selective anion channels in membrane. Confocal imaging resolves granular membrane components including proton pumps and CHGB in puncta on the cell surface after stimulated exocytosis. High pressure freezing immuno-EM reveals a major fraction of CHGB at granule membranes in rat pancreatic β-cells. A cryo-EM structure of bCHGB dimer of a nominal 3.5 Å resolution delineates a central pore with end openings, physically sufficient for membrane-spanning and large single channel conductance. Together our data support that CHGB-containing (CHGB+) channels are characteristic of regulated secretion, and function in granule ion homeostasis near the plasma membrane or possibly in other intracellular processes.

Bright-field to fluorescence microscopy image translation for cell nuclei health quantification

Microscopy is a widely used method in biological research to observe the morphology and structure of cells. Amongst the plethora of microscopy techniques, fluorescent labeling with dyes or antibodies is the most popular method for revealing specific cellular organelles. However, fluorescent labeling also introduces new challenges to cellular observation, as it increases the workload, and the process may result in nonspecific labeling. Recent advances in deep visual learning have shown that there are systematic relationships between fluorescent and bright-field images, thus facilitating image translation between the two. In this article, we propose the cross-attention conditional generative adversarial network (XAcGAN) model. It employs state-of-the-art GANs (GANs) to solve the image translation task. The model uses supervised learning and combines attention-based networks to explore spatial information during translation. In addition, we demonstrate the successful application of XAcGAN to infer the health state of translated nuclei from bright-field microscopy images. The results show that our approach achieves excellent performance both in terms of image translation and nuclei state inference.

Fluctuations of cell geometry and their nonequilibrium thermodynamics in living epithelial tissue

We measure different contributions to entropy production in a living functional epithelial tissue. We do this by extracting the functional dynamics of development while at the same time quantifying fluctuations. Using the translucent Drosophila melanogaster pupal epithelium as an ideal tissue for high-resolution live imaging, we measure the entropy associated with the stochastic geometry of cells in the epithelium. This is done using a detailed analysis of the dynamics of the shape and orientation of individual cells which enables separation of local and global aspects of the tissue behavior. Intriguingly, we find that we can observe irreversible dynamics in the cell geometries but without a change in the entropy associated with those degrees of freedom, showing that there is a flow of energy into those degrees of freedom. Hence, the living system is controlling how the entropy is being produced and partitioned into its different parts.

Imaging the acute abdomen in pregnancy: a radiological decision-making tool and the role of MRI

Acute abdominal pain in pregnancy poses a significant diagnostic challenge. The differential diagnosis is wide, clinical assessment is difficult, and the use of conventional imaging methods is restricted due to risks to the fetus. This can lead to delay in diagnosis, which increases the risk of maternal and fetal harm. Imaging techniques not involving ionising radiation are preferred. Sonography remains first line, but anatomical visualisation can be limited due to displacement of adjacent structures by the gravid uterus. MRI provides excellent cross-sectional soft-tissue assessment of the abdomen and pelvis, and no study to date has demonstrated significant deleterious effects to the fetus at any gestation; however, there remains a theoretical risk of tissue heating by radiofrequency pulses, and there must be consideration of benefit versus potential risk for any use of magnetic resonance imaging (MRI) in pregnancy. With a limited protocol of sequences, a broad spectrum of pathologies can be evaluated. Computed tomography carries the highest exposure of ionising radiation to the fetus, but may be necessary, particularly in cases of trauma. The patient must be kept informed and any potential risks to the patient and fetus should be clearly explained. We present a radiological decision-making tool to guide choice of imaging and best establish the underlying diagnosis in the acute pregnant abdomen. In addition, using illustrative examples from our practice at a large tertiary centre, we review the advantages and disadvantages of each imaging method, with particular focus on the utility of MRI.

Stepped-wedge randomized controlled trial of laparoscopic ventral mesh rectopexy in adults with chronic constipation

Background

The effectiveness of laparoscopic ventral mesh rectopexy (LVMR) in patients with defecatory disorders secondary to internal rectal prolapse is poorly evidenced. A UK-based multicenter randomized controlled trial was designed to determine the clinical efficacy of LVMR compared to controls at medium-term follow-up.

Methods

The randomized controlled trial was conducted from March 1, 2015 TO January 31, 2019. A stepped-wedge RCT design permitted observer-masked data comparisons between patients awaiting LVMR (controls) with those who had undergone surgery. Adult participants with radiologically confirmed IRP refractory to conservative treatment were randomized to three arms with different delays before surgery. Efficacy outcome data were collected at equally stepped time points (12, 24, 36, 48, 60, and 72 weeks). Clinical efficacy of LVMR compared to controls was defined as ≥ 1.0-point reduction in Patient Assessment of Constipation-Quality of Life and/or Symptoms (PAC-QOL and/or PAC-SYM) scores at 24 weeks. Secondary outcome measures included 14-day diary data, the Generalized Anxiety Disorder scale (GAD-7), the Patient Health Questionnaire-9 (PHQ-9), St Marks incontinence score, the Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire (PISQ-12), the chronic constipation Behavioral Response to Illness Questionnaire (CC-BRQ), and the Brief Illness Perception Questionnaire (BIPQ).

Results

Of a calculated sample size of 114, only 28 patients (100% female) were randomized from 6 institutions (due mainly to national pause on mesh-related surgery). Nine were assigned to the T0 arm, 10 to T12, and 9 to T24. There were no substantial differences in baseline characteristics between the three arms. Compared to baseline, significant reduction (improvement) in PAC-QOL and PAC-SYM scores were observed at 24 weeks post-surgery (– 1.09 [95% CI – 1.76, – 0.41], p = 0.0019, and – 0.92 [– 1.52, – 0.32], p = 0.0029, respectively) in the 19 patients available for analysis (9 were excluded for dropout [n = 2] or missing primary outcome [n = 7]). There was a clinically significant long-term reduction in PAC-QOL scores (− 1.38 [− 2.94, 0.19], p = 0.0840 at 72 weeks). Statistically significant improvements in PAC-SYM scores persisted to 72 weeks (− 1.51 [− 2.87, − 0.16], p = 0.0289). Compared to baseline, no differences were found in secondary outcomes, except for significant improvements at 24 and 48 weeks on CC-BRQ avoidance behavior (− 14.3 [95% CI − 23.3, − 5.4], and − 0.92 [− 1.52, − 0.32], respectively), CC-BRQ safety behavior (− 13.7 [95% CI − 20.5, − 7.0], and − 13.0 [− 19.8, − 6.1], respectively), and BIPQ negative perceptions (− 16.3 [95% CI − 23.5, − 9.0], and − 10.5 [− 17.9, − 3.2], respectively).

Conclusions

With the caveat of under-powering due to poor recruitment, the study presents the first randomized trial evidence of short-term benefit of LVMR for internal rectal prolapse.

Trial registration

ISRCTN Registry (ISRCTN11747152).

Supplementary Information

The online version contains supplementary material available at 10.1007/s10151-022-02633-w.

Scale-up of ABC care bundle for intracerebral haemorrhage across two hyperacute stroke units in one region in England: a mixed methods evaluation of a quality improvement project

Background

Intracerebral haemorrhage (ICH) accounts for 10%–15% of strokes in the UK, but is responsible for half of all annual global stroke deaths. The ABC bundle for ICH was developed and implemented at Salford Royal Hospital, and was associated with a 44% reduction in 30-day case fatality. Implementation of the bundle was scaled out to the other hyperacute stroke units (HASUs) in the region from April 2017. A mixed methods evaluation was conducted alongside to investigate factors influencing implementation of the bundle across new settings, in order to provide lessons for future spread.

Methods

A harmonised quality improvement registry at each HASU captured consecutive patients with spontaneous ICH from October 2016 to March 2018 to capture process and outcome measures for preimplementation (October 2016 to March 2017) and implementation (April 2017 to March 2018) time periods. Statistical analyses were performed to determine differences in process measures and outcomes before and during implementation. Multiple qualitative methods (interviews, non-participant observation and project document analysis) captured how the bundle was implemented across the HASUs.

Results

HASU1 significantly reduced median anticoagulant reversal door-to-needle time from 132 min (IQR: 117–342) preimplementation to 76 min (64–113.5) after implementation and intensive blood pressure lowering door to target time from 345 min (204–866) preimplementation to 84 min (60–117) after implementation. No statistically significant improvements in process targets were observed at HASU2. No significant change was seen in 30-day mortality at either HASU. Qualitative evaluation identified the importance of facilitation during implementation and identified how contextual changes over time impacted on implementation. This identified the need for continued implementation support.

Conclusion

The findings show how the ABC bundle can be successfully implemented into new settings and how challenges can impede implementation. Findings have been used to develop an implementation strategy to support future roll out of the bundle outside the region.

3D assessment of intervertebral disc degeneration in zebrafish identifies changes in bone density that prime disc disease

Back pain is a common condition with a high social impact and represents a global health burden. Intervertebral disc disease (IVDD) is one of the major causes of back pain; no therapeutics are currently available to reverse this disease. The impact of bone mineral density (BMD) on IVDD has been controversial, with some studies suggesting osteoporosis as causative for IVDD and others suggesting it as protective for IVDD. Functional studies to evaluate the influence of genetic components of BMD in IVDD could highlight opportunities for drug development and repurposing. By taking a holistic 3D approach, we established an aging zebrafish model for spontaneous IVDD. Increased BMD in aging, detected by automated computational analysis, is caused by bone deformities at the endplates. However, aged zebrafish spines showed changes in bone morphology, microstructure, mineral heterogeneity, and increased fragility that resembled osteoporosis. Elements of the discs recapitulated IVDD symptoms found in humans: the intervertebral ligament (equivalent to the annulus fibrosus) showed disorganized collagen fibers and herniation, while the disc center (nucleus pulposus equivalent) showed dehydration and cellular abnormalities. We manipulated BMD in young zebrafish by mutating sp7 and cathepsin K, leading to low and high BMD, respectively. Remarkably, we detected IVDD in both groups, demonstrating that low BMD does not protect against IVDD, and we found a strong correlation between high BMD and IVDD. Deep learning was applied to high-resolution synchrotron µCT image data to analyze osteocyte 3D lacunar distribution and morphology, revealing a role of sp7 in controlling the osteocyte lacunar 3D profile. Our findings suggest potential avenues through which bone quality can be targeted to identify beneficial therapeutics for IVDD.

A Floating Mold Technique for the Programmed Assembly of Protocells into Protocellular Materials Capable of Non-Equilibrium Biochemical Sensing

Despite important breakthroughs in bottom-up synthetic biology, a major challenge still remains the construction of free-standing, macroscopic, and robust materials from protocell building blocks that are stable in water and capable of emergent behaviors. Herein, a new floating mold technique for the fabrication of millimeter- to centimeter-sized protocellular materials (PCMs) of any shape that overcomes most of the current challenges in prototissue engineering is reported. Significantly, this technique also allows for the generation of 2D periodic arrays of PCMs that display an emergent non-equilibrium spatiotemporal sensing behavior. These arrays are capable of collectively translating the information provided by the external environment and are encoded in the form of propagating reaction-diffusion fronts into a readable dynamic signal output. Overall, the methodology opens up a route to the fabrication of macroscopic and robust tissue-like materials with emergent behaviors, providing a new paradigm of bottom-up synthetic biology and biomimetic materials science.

Tetherin/BST2, a physiologically and therapeutically relevant regulator of platelet receptor signalling

The reactivity of platelets, which play a key role in the pathogenesis of atherothrombosis, is tightly regulated. The integral membrane protein tetherin/bone marrow stromal antigen-2 (BST-2) regulates membrane organization, altering both lipid and protein distribution within the plasma membrane. Because membrane microdomains have an established role in platelet receptor biology, we sought to characterize the physiological relevance of tetherin/BST-2 in those cells. To characterize the potential importance of tetherin/BST-2 to platelet function, we used tetherin/BST-2-/- murine platelets. In the mice, we found enhanced function and signaling downstream of a subset of membrane microdomain-expressing receptors, including the P2Y12, TP thromboxane, thrombin, and GPVI receptors. Preliminary studies in humans have revealed that treatment with interferon-α (IFN-α), which upregulates platelet tetherin/BST-2 expression, also reduces adenosine diphosphate-stimulated platelet receptor function and reactivity. A more comprehensive understanding of how tetherin/BST-2 negatively regulates receptor function was provided in cell line experiments, where we focused on the therapeutically relevant P2Y12 receptor (P2Y12R). Tetherin/BST-2 expression reduced both P2Y12R activation and trafficking, which was accompanied by reduced receptor lateral mobility specifically within membrane microdomains. In fluorescence lifetime imaging-Förster resonance energy transfer (FLIM-FRET)-based experiments, agonist stimulation reduced basal association between P2Y12R and tetherin/BST-2. Notably, the glycosylphosphatidylinositol (GPI) anchor of tetherin/BST-2 was required for both receptor interaction and observed functional effects. In summary, we established, for the first time, a fundamental role of the ubiquitously expressed protein tetherin/BST-2 in negatively regulating membrane microdomain-expressed platelet receptor function.

Wnt16 Elicits a Protective Effect Against Fractures and Supports Bone Repair in Zebrafish

Bone homeostasis is a dynamic, multicellular process that is required throughout life to maintain bone integrity, prevent fracture, and respond to skeletal damage. WNT16 has been linked to bone fragility and osteoporosis in human genome wide‐association studies, as well as the functional hematopoiesis of leukocytes in vivo. However, the mechanisms by which WNT16 promotes bone health and repair are not fully understood. In this study, CRISPR‐Cas9 was used to generate mutant zebrafish lacking Wnt16 (wnt16^−/−) to study its effect on bone dynamically. The wnt16 mutants displayed variable tissue mineral density (TMD) and were susceptible to spontaneous fractures and the accumulation of bone calluses at an early age. Fractures were induced in the lepidotrichia of the caudal fins of wnt16^−/− and WT zebrafish; this model was used to probe the mechanisms by which Wnt16 regulates skeletal and immune cell dynamics in vivo. In WT fins, wnt16 expression increased significantly during the early stages for bone repair. Mineralization of bone during fracture repair was significantly delayed in wnt16 mutants compared with WT zebrafish. Surprisingly, there was no evidence that the recruitment of innate immune cells to fractures or soft callus formation was altered in wnt16 mutants. However, osteoblast recruitment was significantly delayed in wnt16 mutants postfracture, coinciding with precocious activation of the canonical Wnt signaling pathway. In situ hybridization suggests that canonical Wnt‐responsive cells within fractures are osteoblast progenitors, and that osteoblast differentiation during bone repair is coordinated by the dynamic expression of runx2a and wnt16. This study highlights zebrafish as an emerging model for functionally validating osteoporosis–associated genes and investigating fracture repair dynamically in vivo. Using this model, it was found that Wnt16 protects against fracture and supports bone repair, likely by modulating canonical Wnt activity via runx2a to facilitate osteoblast differentiation and bone matrix deposition. © 2021 The Authors. JBMR Plus published by Wiley Periodicals LLC. on behalf of American Society for Bone and Mineral Research.

Environmental Factors and Hyperacute Stroke Care Activity During the COVID-19 Pandemic: An Interrupted Time-Series Analysis

BACKGROUND AND AIMS

Concerns have arisen regarding patient access and delivery of acute stroke care during the COVID-19 pandemic. We investigated key population level events on activity of the three hyperacute stroke units (HASUs) within Greater Manchester and East Cheshire (GM & EC), whilst adjusting for environmental factors.

METHODS

Weekly stroke admission & discharge counts in the three HASUs were collected locally from Emergency Department (ED) data and Sentinel Stroke National Audit Programme core dataset prior to, and during the emergence of the COVID-19 pandemic (Jan 2020 to May 2020). Whilst adjusting for local traffic-related air pollution and ambient measurement, an interrupted time-series analysis using a segmented generalised linear model investigated key population level events on the rate of stroke team ED assessments, admissions for stroke, referrals for transient ischaemic attack (TIA), and stroke discharges.

RESULTS

The median total number of ED stroke assessments, admissions, TIA referrals, and discharges across the three HASU sites prior to the first UK COVID-19 death were 150, 114, 69, and 76 per week. The stable weekly trend in ED assessments and stroke admissions decreased by approximately 16% (and 21% for TIAs) between first UK hospital COVID-19 death (5th March) and the implementation of the Act-FAST campaign (6th April) where a modest 4% and 5% increase per week was observed. TIA referrals increased post Government intervention (23rd March), without fully returning to the numbers observed in January and February. Trends in discharges from stroke units appeared unaffected within the study period reported here.

CONCLUSION

Despite adjustment for environmental factors stroke activity was temporarily modified by the COVID-19 pandemic. Underlying motivations within the population are still not clear. This raises concerns that patients may have avoided urgent health care risking poorer short and long-term health outcomes.

Vascular bowel and mesenteric injury in blunt abdominal trauma: a single centre experience

AIM

To establish common patterns of injury in vascular bowel and mesenteric injury (VBMI) and to identify any factors that may lead to delayed treatment.

METHODS AND MATERIALS

Forty-one patients with blunt VBMI presented to the level 1 trauma centre of the The Royal London Hospital over 5 years. Computed tomography (CT) images were reviewed to identify the specific location of injury and additional features such as seatbelt bruising and lumbar hernias. Surgical reports were reviewed to record any pertinent surgical findings at laparotomy.

RESULTS

The commonest mechanism of injury was a restrained car occupant involved in a road traffic collision (49%, n=20). The ileocaecal mesenteric vasculature was most frequently injured (41.5%, n=17), followed by the mid ileum (17.1%, n=7). Seatbelt bruising was identified in 80% of restrained car occupants and lumbar hernias in 22% of all patients with VBMI.

CONCLUSION

Restrained car occupants involved in road traffic collisions are at increased risk of VBMI with particular susceptibility of the ileocaecal mesentery. This has implications for the reporting radiologist and trauma surgeon in deciding which patients require careful monitoring for the development of delayed bowel ischaemia.

Encoding of facial expressions in individuals with adult-onset myotonic dystrophy type 1

Introduction: Emotional issues are often reported among individuals with myotonic dystrophy type 1 (DM1) and some studies have suggested that deficits in ability to quickly encode emotions may contribute to these problems. However, poor performance on emotion encoding tasks could also be explained by a more general cognitive deficit (Full Scale IQ [FSIQ]), rather than a specific deficit in emotional processing. Since individuals with DM1 are known to exhibit difficulties in general cognitive abilities, it is important to account for FSIQ when evaluating emotion encoding. The aim of this study was to compare emotion encoding abilities between individuals with and without DM1, while adjusting for the impact of general cognitive abilities (FSIQ). Methods: The sample included 35 individuals with adult-onset DM1 and 54 unaffected adults who completed assessments of emotion encoding abilities (Ekman faces test) and general cognitive abilities (Wechsler Adult Intelligence Scale-IV). Performance on the emotion encoding task was operationalized as proportion correct and response time. Group differences in proportion correct were evaluated with generalized linear regression, while linear regression models were used to determine the effect of group on response time. Models were adjusted for age, sex, and FSIQ. The false discovery rate (FDR) was applied to control false positives due to multiple comparisons (p_fdr ). Results: No significant group differences were observed for emotion encoding abilities (all p_fdr > 0.13). FSIQ was significantly associated with proportion correct and with response time (all p_fdr < 0.05). Conclusions: Emotion encoding appears intact in individuals with DM1 and variation in the ability to encode facial expressions was associated with FSIQ. Further research is required to address the relationship between general cognitive abilities and emotion encoding abilities among DM1 patients.

DARPA’s Impact on Artificial Intelligence

The Defense Advanced Research Project Agency’s (DARPA) mission is to make pivotal investments leading to research breakthroughs that support national security. DARPA artificial intelligence (AI) programs have emphasized the need for machines to perceive and interact with the world around them; to frame problems and to arrive at solutions and decisions based on reasoning; to implement those decisions, perhaps through consultation with a human or another machine; to learn; to explain the rationale for decisions; to adhere to rules of ethical behavior defined for humans; to adapt to dynamic environments; and, to do all of this in real-time. In short, DARPA has always been interested in AI frameworks that integrate AI and computer science technologies, and the application of those frameworks to DARPA-hard problems. In this article, we describe the significant role that DARPA has played in the establishment of AI, and introduce six articles that explore DARPA’s Three Waves of AI.

Introducing PEEP: The psychiatry early experience programme

At Guy's King's and St Thomas’ School of Medicine, a unique initiative is the Psychiatry Early Experience Programme (PEEP), which allows students to shadow psychiatry trainees at work several times a year. The students’ attitudes towards psychiatry and the scheme are regularly assessed and initial results are already available.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Simultaneous Determination of Multiple Tetracycline Residues in Milk by Metal Chelate Affinity Chromatography: Collaborative Study

To meet federal and state regulatory needs, a liquid chromatographic (LC) method with ultraviolet (UV) detection was developed for determination of 7 tetracyclines at 30 ng/mL in milk. Raw milk samples are defatted, acidified, and centrifuged to remove proteins, and tetracyclines are specifically absorbed from the milk by chelation with metal ions bound to small Chelating Sepharose Fast Flow columns. Tetracyclines are removed from these columns with EDTA-containing buffer, and extracts are further cleaned by ultrafiltration. Finally, extracts are concentrated and analyzed simultane ously by using on-line concentration. This method was validated in a collaborative study that involved 11 laboratories, including the authors’ laboratory. Each laboratory was asked to prepare and analyze known control and fortified milk samples, as well as 18 coded blind samples. Eight laboratories completed all analyses. Average interlaboratory recoveries for the known fortified samples ranged from 59% (methacycline at 15 ng/mL) to 78% (oxytetracy cline at 60 ng/mL). Average recovery for each of 7 residues at 30 ng/mL were between 60 and 110%, meeting single-residue guidelines for accuracy set by the U.S. Food and Drug Administration. Reproducibility relative standard deviation (RSDR) for the known fortified samples varied from 11 to 39%, with 6 of 7 residues at the 30 ng/mL level having RSDR values at or below 20%. Seven of 8 laboratories correctly identified blind control milk samples and all 28 residues present in blind samples. The metal chelate affinity—LC method for determination of multiple tetracycline residues in milk has been adopted first action by AOAC INTERNATIONAL.

Myotonic dystrophy type 1 alters muscle twitch properties, spinal reflexes, and perturbation-induced trans-cortical reflexes

BACKGROUND

Neurophysiologic biomarkers are needed for clinical trials of therapies for myotonic dystrophy (DM1). We characterized muscle properties, spinal reflexes (H-reflexes), and trans-cortical long-latency reflexes (LLRs) in a cohort with mild/moderate DM1.

METHODS

Twenty-four people with DM1 and 25 matched controls underwent assessment of tibial nerve H-reflexes and soleus muscle twitch properties. Quadriceps LLRs were elicited by delivering an unexpected perturbation during a single-limb squat (SLS) visuomotor tracking task.

RESULTS

DM1 was associated with decreased H-reflex depression. The efficacy of doublet stimulation was enhanced, yielding an elevated double-single twitch ratio. DM1 participants demonstrated greater error during the SLS task. DM1 individuals with the least-robust LLR responses showed the greatest loss of spinal H-reflex depression.

CONCLUSIONS

DM1 is associated with abnormalities of muscle twitch properties. Co-occurring alterations of spinal and trans-cortical reflex properties underscore the central nervous system manifestations of this disorder and may assist in gauging efficacy during clinical trials.

Scleraxis genes are required for normal musculoskeletal development and for rib growth and mineralization in zebrafish

Tendons are an essential part of the musculoskeletal system, connecting muscle and skeletal elements to enable force generation. The transcription factor scleraxis marks vertebrate tendons from early specification. Scleraxis-null mice are viable and have a range of tendon and bone defects in the trunk and limbs but no described cranial phenotype. We report the expression of zebrafish scleraxis orthologs: scleraxis homolog (scx)-a and scxb in cranial and intramuscular tendons and in other skeletal elements. Single mutants for either scxa or scxb, generated by clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9), are viable and fertile as adult fish. Although scxb mutants show no obvious phenotype, scxa mutant embryos have defects in cranial tendon maturation and muscle misalignment. Mutation of both scleraxis genes results in more severe defects in cranial tendon differentiation, muscle and cartilage dysmorphogenesis and paralysis, and lethality by 2-5 wk, which indicates an essential function of scleraxis for craniofacial development. At juvenile and adult stages, ribs in scxa mutants fail to mineralize and/or are small and heavily fractured. Scxa mutants also have smaller muscle volume, abnormal swim movement, and defects in bone growth and composition. Scleraxis function is therefore essential for normal craniofacial form and function and vital for fish development.-Kague, E., Hughes, S. M., Lawrence, E. A., Cross, S., Martin-Silverstone, E., Hammond, C. L., Hinits, Y. Scleraxis genes are required for normal musculoskeletal development and for rib growth and mineralization in zebrafish.

Ventricular interaction in the jugular venous pulse in aortic regurgitation

A patient with severe aortic regurgitation due to rapidly progressive staphylococcal endocarditis demonstrated an unusual physical sign of prominent diastolic venous pulsation. We suggest that this venous pulse is the result of diastolic ventricular interaction in which inflow of blood into the right ventricle is arrested in the latter part of diastole due to extreme left ventricular distension. We wish to highlight this sign so that others can look for it with the aim of improving our understanding and treatment of ventricular interaction associated with heart failure.

661W Photoreceptor Cell Line as a Cell Model for Studying Retinal Ciliopathies

The retina contains several ciliated cell types, including the retinal pigment epithelium (RPE) and photoreceptor cells. The photoreceptor cilium is one of the most highly modified sensory cilia in the human body. The outer segment of the photoreceptor is a highly elaborate primary cilium, containing stacks or folds of membrane where the photopigment molecules are located. Perhaps unsurprisingly, defects in cilia often lead to retinal phenotypes, either as part of syndromic conditions involving other organs, or in isolation in the so-called retinal ciliopathies. The study of retinal ciliopathies has been limited by a lack of retinal cell lines. RPE1 retinal pigment epithelial cell line is commonly used in such studies, but the existence of a photoreceptor cell line has largely been neglected in the retinal ciliopathy field. 661W cone photoreceptor cells, derived from mouse, have been widely used as a model for studying macular degeneration, but not described as a model for studying retinal ciliopathies such as retinitis pigmentosa. Here, we characterize the 661W cell line as a model for studying retinal ciliopathies. We fully characterize the expression profile of these cells, using whole transcriptome RNA sequencing, and provide this data on Gene Expression Omnibus for the advantage of the scientific community. We show that these cells express the majority of markers of cone cell origin. Using immunostaining and confocal microscopy, alongside scanning electron microscopy, we show that these cells grow long primary cilia, reminiscent of photoreceptor outer segments, and localize many cilium proteins to the axoneme, membrane and transition zone. We show that siRNA knockdown of cilia genes Ift88 results in loss of cilia, and that this can be assayed by high-throughput screening. We present evidence that the 661W cell line is a useful cell model for studying retinal ciliopathies.

ER-to-Golgi trafficking of procollagen in the absence of large carriers

Trafficking of procollagen is essential for normal cell function. Here, imaging of GFP-tagged type I procollagen reveals that it is transported from the endoplasmic reticulum to the Golgi, without the use of large carriers.

Secretion and assembly of collagen are fundamental to the function of the extracellular matrix. Defects in the assembly of a collagen matrix lead to pathologies including fibrosis and osteogenesis imperfecta. Owing to the size of fibril-forming procollagen molecules it is assumed that they are transported from the endoplasmic reticulum to the Golgi in specialized large COPII-dependent carriers. Here, analyzing endogenous procollagen and a new engineered GFP-tagged form, we show that transport to the Golgi occurs in the absence of large (>350 nm) carriers. Large GFP-positive structures were observed occasionally, but these were nondynamic, are not COPII positive, and are labeled with markers of the ER. We propose a short-loop model of COPII-dependent ER-to-Golgi traffic that, while consistent with models of ERGIC-dependent expansion of COPII carriers, does not invoke long-range trafficking of large vesicular structures. Our findings provide an important insight into the process of procollagen trafficking and reveal a short-loop pathway from the ER to the Golgi, without the use of large carriers.

Improving Population-Wide Collection of Stage at Diagnosis for Childhood Cancer: International Collaboration and Progress

Background: There are huge international disparities in childhood cancer survival. The International Agency for Research on Cancer's Global Initiative for Cancer Registry Development has improved cancer registry coverage of the world's population, particularly in low- and middle-income countries (LMICs). However, for virtually all registries around the world, the challenge remains of collecting comparable and population-wide information on stage at diagnosis. This information is essential to understand and address disparities in outcomes. In response to this, a UICC-endorsed set of consensus guidelines for assigning stage for 16 of the most common types of childhood cancer was recently developed (the Toronto Guidelines), for use by population registries in both high and LMICs. Aim: To trial the Toronto Guidelines on a population-basis, and develop a structured protocol, suitable for global implementation, for collecting the required data elements and assigning cancer stage at diagnosis for childhood cancer. Methods: Using an innovative approach, data items as defined in the Toronto Guidelines were gathered from the medical record and entered electronically. Stage at diagnosis was assigned automatically using computer algorithms, thus reducing errors and maximizing consistency. Data collection and assignment of stage were incorporated into an online platform that was then trialed in the national childhood cancer registries of Australia and New Zealand for cases diagnosed between 2006 and 2014. Results: Stage at diagnosis was successfully assigned for 94% of all eligible patients (n=1662) across both countries. In contrast, stage as recorded by the treating clinician was located in the medical record for only 39% of cases in Australia. Conclusion: Practical implementation of the Toronto Guidelines has been highly successful to date and further testing is planned in LMICs. This approach has the potential to improve global epidemiologic monitoring of childhood cancer and lead to better understanding of the reasons underlying disparities in outcome.

Interleukin-4 activated macrophages mediate immunity to filarial helminth infection by sustaining CCR3-dependent eosinophilia

Eosinophils are effectors in immunity to tissue helminths but also induce allergic immunopathology. Mechanisms of eosinophilia in non-mucosal tissues during infection remain unresolved. Here we identify a pivotal function of tissue macrophages (Mϕ) in eosinophil anti-helminth immunity using a BALB/c mouse intra-peritoneal Brugia malayi filarial infection model. Eosinophilia, via C-C motif chemokine receptor (CCR)3, was necessary for immunity as CCR3 and eosinophil impairments rendered mice susceptible to chronic filarial infection. Post-infection, peritoneal Mϕ populations proliferated and became alternatively-activated (AAMϕ). Filarial AAMϕ development required adaptive immunity and interleukin-4 receptor-alpha. Depletion of Mϕ prior to infection suppressed eosinophilia and facilitated worm survival. Add back of filarial AAMϕ in Mϕ-depleted mice recapitulated a vigorous eosinophilia. Transfer of filarial AAMϕ into Severe-Combined Immune Deficient mice mediated immunological resistance in an eosinophil-dependent manner. Exogenous IL-4 delivery recapitulated tissue AAMϕ expansions, sustained eosinophilia and mediated immunological resistance in Mϕ-intact SCID mice. Co-culturing Brugia with filarial AAMϕ and/or filarial-recruited eosinophils confirmed eosinophils as the larvicidal cell type. Our data demonstrates that IL-4/IL-4Rα activated AAMϕ orchestrate eosinophil immunity to filarial tissue helminth infection.

Helminths parasitize approximately one quarter of the global population. Medically-important helminths, including filariae responsible for elephantiasis and river blindness, are targeted for elimination as a public health problem. Currently there are no vaccines or immunotherapeutics available for filarial worms or other human helminth pathogens. Here we define a cellular mechanism whereby the interlukin-4 dependent activation of tissue macrophages are essential to sustain the recruitment of larvicidal eosinophil granulocytes, leading to immunity against filarial infection at a sterile tissue site of parasitism. This work delineates the relative non-redundant functional roles of both myeloid cell types in ‘type-2’ immunity to helminth infection. The study represents a mechanistic advance in our understanding of how immunity operates against metazoan macroparasites invading sterile tissues and may be used in the rational design of new therapeutics to limit helminth disease.

Malignant melanoma presenting as amelanotic caruncular lesion in a child

Conjunctival melanoma is a rare malignant neoplasm that can present in childhood in any part of the conjunctiva. The infrequency with which conjunctival melanoma is encountered in childhood caruncular lesions makes it a formidable but important aspect of the differential diagnosis. We report the case of a 10-year-old boy who presented with a left caruncular lesion. On histopathologic analysis, the lesion was determined to be BRAF-negative invasive melanoma arising in association with melanocytic nevus. The melanoma was excised using no-touch technique and double freeze thaw cryotherapy. A full systemic work-up revealed no metastasis or abnormality.

Wnt signalling controls the response to mechanical loading during zebrafish joint development

Joint morphogenesis requires mechanical activity during development. Loss of mechanical strain causes abnormal joint development, which can impact long-term joint health. Although cell orientation and proliferation are known to shape the joint, dynamic imaging of developing joints in vivo has not been possible in other species. Using genetic labelling techniques in zebrafish we were able, for the first time, to dynamically track cell behaviours in intact moving joints. We identify that proliferation and migration, which contribute to joint morphogenesis, are mechanically controlled and are significantly reduced in immobilised larvae. By comparison with strain maps of the developing skeleton, we identify canonical Wnt signalling as a candidate for transducing mechanical forces into joint cell behaviours. We show that, in the jaw, Wnt signalling is reduced specifically in regions of high strain in response to loss of muscle activity. By pharmacological manipulation of canonical Wnt signalling, we demonstrate that Wnt acts downstream of mechanical activity and is required for joint patterning and chondrocyte maturation. Wnt16, which is also downstream of muscle activity, controls proliferation and migration, but plays no role in chondrocyte intercalation.

Comparing the educational impact of simulation training to role play and didactic teaching for integrating mental and physical healthcare

Introduction

Addressing the interaction between mental and physical health to provide more integrated healthcare has been highlighted as an international priority for health and education systems. Educational interventions focusing on multi-disciplinary, interprofessional approaches to integrated mental and physical healthcare are an essential part of transforming health systems. Simulation training is one tool by which such training can be delivered, in contrast to traditional teaching methods. However, simulation training can be high-cost and clarity over the impact is required.

Aim

To compare simulation training for integrating mental and physical health to role-play and didactic teaching, on their effect on confidence, knowledge, and attitudes of participants.

Methods

Participants in simulation training (n = 24) and role play plus didactic teaching (n = 87) both completed self-report measures of confidence and knowledge in working with mental and physical health needs, as well as the Readiness for interprofessional learning scale (RIPLS) collecting attitudes towards interprofessional collaboration. All participants also completed post-course qualitative feedback form with open questions.

Results

T-tests found statistically significant increases in confidence and knowledge following both educational interventions. T-tests showed statistically significant increases in attitudes to interprofessional collaboration (RIPLS) following simulation training, while there were no statistically significant changes after role-play and didactic teaching. Thematic analyses of post-course open questions demonstrated differing learning outcomes.

Conclusions

Simulation training appears to have a different and beneficial impact to role play and didactic teaching alone, when training participants on integrating mental and physical health.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Who Learns More in Interprofessional Mental Health Simulation Training? A Study Comparing Learning Outcomes of Different Professionals who Work in Mental and Physical Health Care Settings

Introduction

Simulation training has the potential to develop communication and teamwork skills, as well as technical knowledge and competency. Mental health simulation training aims to promote awareness of mental health conditions and to enhance human factors (or non-technical) skills that will enable professionals that work in mental and physical healthcare settings to improve their collaborative and patient-centered clinical practice. This study explored the differences in learning outcomes after a mental health simulation course between different professionals–nursing staff, medical staff, and allied health professionals.

Aims and objectives This project examined the different learning outcomes of human factors, confidence and knowledge, for nursing, medical and allied health professionals following mental health simulation training.

Methods

Course-specific measures of confidence and knowledge were administered pre- and post-training to all participants, in addition to The Human Factors Skills for Healthcare Instrument (HFSHI). A post-course evaluation for with free-text responses to open questions regarding the impact of the training was utilised to collect qualitative data.

Results

With data collection ongoing, preliminary results indicate differences in learning outcome depending on professional background, both in terms of quantitative measures and qualitative findings.

Conclusions

Learning outcomes may differ for different professionals despite receiving the same simulation training focusing on mental and physical health, evidencing the importance of sharing individual learning experiences in simulation using a debrief model.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Creating safer health systems: Lessons from other sectors and an account of an application in the Safer Clinical Systems programme

Despite well meaning initiatives over decades, the percentage of inpatients suffering adverse events remains constant in most advanced health systems. The notion of incident reporting as used in other safety critical industries has proved far less effective in healthcare. This article describes a new patient safety paradigm in the search for improved patient safety in healthcare. Underpinned by a holistic use of human factors the Safer Clinical Systems programme involves a proactive, risk-based approach seeking to eliminate or control risk before it is converted to patient harm. The tools and techniques applied by healthcare professional in real-life settings are described along with the outcomes of a significant reduction in risk and improvement in safety culture as measured by the Safety Culture Index. The challenges of applying the approach are discussed but it is argued that important progress could be made if a critical mass of healthcare staff were helped to acquire skills in human factors.

Long Term Patient Reported Urinary Function Following External Beam Radiotherapy for Prostate Cancer

INTRODUCTION

This study reports long-term patient reported urinary function and urinary-related quality of life (uQoL) after external beam radiotherapy (EBRT) for localized prostate cancer.

METHODS

574 men underwent definitive prostate EBRT to 70-78 Gy±androgen deprivation therapy between 2000 and 2009. The median follow-up from EBRT was 44 months. Patients were evaluated at baseline (pre-EBRT) and at intervals post-treatment using the International Prostate Symptom Score (IPSS) instrument.

RESULTS

Patients with mild IPSS at baseline (total 0-7) reported median total scores of 3, 4 and 3 at baseline, 6 and 48 months respectively post-EBRT. For patients with moderate IPSS at baseline (total 8-19), median total IPSS was 12 at baseline and 9 at both 6 and 48 months. For the severe IPSS group at baseline (total 20-35), the median total IPSS was 24, 12 and 14 at baseline, 6 and 48 months post-EBRT. The cumulative risk of persistent IPSS increase (greater than 5 points above baseline) at 48 months was 16%, 10% and 6% for patients with mild, moderate and severe baseline IPSS respectively. 94%, 54% and 11% of patients with mild, moderate and severe baseline IPSS reported good uQoL at baseline respectively, with these proportions increasing to 95%, 83% and 69% at 48 months.

CONCLUSION

Urinary symptoms and uQoL as measured by the IPSS instrument remained stable or improved for the majority of men after definitive EBRT with or without ADT for prostate cancer. This was especially notable for the group of men with worse baseline symptoms or uQoL, with risk of persistent worsening of urinary symptoms decreasing with higher baseline IPSS category. Understanding the expected pattern of urinary symptoms and related uQoL in the months and years following EBRT taking into account baseline urinary function is highly valuable for counselling men as part of the therapeutic decision-making process.

Radiological assessment of paediatric cervical spine injury in blunt trauma: the potential impact of new NICE guidelines on the use of CT

AIM

To determine the potential effect of changes to the National Institute for Health and Care Excellence (NICE) guidelines to the use of computed tomography (CT) in the assessment of suspected paediatric cervical spine (c-spine) injury.

MATERIAL AND METHODS

A 5 year retrospective study was conducted of c-spine imaging in paediatric (<10 years) patients presenting following blunt trauma at a Level 1 trauma centre in London. All patients under the age of 10 years who underwent any imaging of the c-spine following blunt trauma were included. Clinical data relating to the presenting signs and symptoms were obtained from the retrospective review of electronic records and paper notes. This was then applied to the previous NICE guideline (CG56) and to the new NICE guideline (CG176). Patients with incomplete data were excluded.

RESULTS

Two hundred and seventy-eight patients <10 years underwent imaging of the c-spine following blunt trauma. Two hundred and seventy (97.12%) examinations had complete data and were included in further analysis. One hundred and forty-nine (55.19%) met the criteria for a CT of the c-spine under NICE CG56, whereas 252 (93.33%) met the updated NICE CG176 criteria for c-spine CT. Five (1.85%) patients had a c-spine injury and met the criteria under both CG56 and CG176 NICE guidelines.

CONCLUSION

Recent changes to NICE Head Injury Guidelines relating to radiological assessment of paediatric c-spine following blunt trauma are likely to result in an increased usage of CT as the initial radiological investigation over plain radiographs, without an apparent increase in specificity in the present series.

Using Confocal Analysis of Xenopus laevis to Investigate Modulators of Wnt and Shh Morphogen Gradients

This protocol describes a method to visualise ligands distributed across a field of cells. The ease of expressing exogenous proteins, together with the large size of their cells in early embryos, make Xenopus laevis a useful model for visualising GFP-tagged ligands. Synthetic mRNAs are efficiently translated after injection into early stage Xenopus embryos, and injections can be targeted to a single cell. When combined with a lineage tracer such as membrane tethered RFP, the injected cell (and its descendants) that are producing the overexpressed protein can easily be followed. This protocol describes a method for the production of fluorescently tagged Wnt and Shh ligands from injected mRNA. The methods involve the micro dissection of ectodermal explants (animal caps) and the analysis of ligand diffusion in multiple samples. By using confocal imaging, information about ligand secretion and diffusion over a field of cells can be obtained. Statistical analyses of confocal images provide quantitative data on the shape of ligand gradients. These methods may be useful to researchers who want to test the effects of factors that may regulate the shape of morphogen gradients.

A MultiCenter Pilot Randomized Controlled Trial of Remote Ischemic Preconditioning in Major Vascular Surgery

A pilot randomized controlled trial that evaluated the effect of remote ischemic preconditioning (RIPC) on clinical outcomes following major vascular surgery was performed. Eligible patients were those scheduled to undergo open abdominal aortic aneurysm repair, endovascular aortic aneurysm repair, carotid endarterectomy, and lower limb revascularization procedures. Patients were randomized to RIPC or to control groups. The primary outcome was a composite clinical end point comprising any of cardiovascular death, myocardial infarction, new-onset arrhythmia, cardiac arrest, congestive cardiac failure, cerebrovascular accident, renal failure requiring renal replacement therapy, mesenteric ischemia, and urgent cardiac revascularization. Secondary outcomes were components of the primary outcome and myocardial injury as assessed by serum troponin values. The primary outcome occurred in 19 (19.2%) of 99 controls and 14 (14.1%) of 99 RIPC group patients ( P = .446). There were no significant differences in secondary outcomes. Our trial generated data that will guide future trials. Further trials are urgently needed.