Rac activation and inactivation control plasticity of tumor cell movement.

Tumor cells exhibit two different modes of individual cell movement. Mesenchymal-type movement is characterized by an elongated cellular morphology and requires extracellular proteolysis. In amoeboid movement, cells have a rounded morphology, are less dependent on proteases, and require high Rho-kinase signaling to drive elevated levels of actomyosin contractility. These two modes of cell movement are interconvertible. We show that mesenchymal-type movement in melanoma cells is driven by activation of the GTPase Rac through a complex containing NEDD9, a recently identified melanoma metastasis gene, and DOCK3, a Rac guanine nucleotide exchange factor. Rac signals through WAVE2 to direct mesenchymal movement and suppress amoeboid movement through decreasing actomyosin contractility. Conversely, in amoeboid movement, Rho-kinase signaling activates a Rac GAP, ARHGAP22, that suppresses mesenchymal movement by inactivating Rac. We demonstrate tight interplay between Rho and Rac in determining different modes of tumor cell movement, revealing how tumor cells switch between different modes of movement.

Selecting the optimal treatment for left main coronary disease: The importance of identifying subgroups of patients.

Randomized trials of stenting versus surgery for patients with unprotected left main (LM) coronary stenosis have largely shown similar survival between the two interventions. However, patients with LM stenosis represent a heterogeneous group in which subgroups likely to benefit from one therapy more than another are difficult to identify. Increasing coronary disease burden is the most accepted subgrouping for identifying optimal therapy but this can be defined in more detail allowing greater discrimination. Competitive flow reduces bypass graft patency in patients with isolated LM stenosis and complex bifurcation stenoses reduce the effectiveness of coronary stenting. The evidence for LM stenosis subgroupings is presented.

Intracardiac Echocardiography for Point-of-Care Guided Left Ventricular Assist Device Implantation: Surgical Implications for COVID-19.

Data from animal models is now available to initiate assessment of human safety and feasibility of wide-angle three-dimensional intracardiac echocardiography (3D ICE) to guide point-of-care implantation of percutaneous left ventricular assist devices in critical care settings. Assessment of these combined new technologies could be best achieved within a surgical institution with pre-existing expertise in separate utilization of ICE and Impella.

Implementation of the Versius robotic surgical system for colorectal cancer surgery: First clinical experience.

BACKGROUND: The Versius surgical system, from CMR Surgical, is the first UK-based robotic platform to become commercially available. This is a prospective series in accordance with the IDEAL development framework for surgical innovation reporting the clinical implementation and initial experience using this robotic platform. METHODS: Patients with colorectal cancer were included. Exclusion criteria included T4 tumours, ultra-low rectal cancer and severe comorbidity (American Society of Anesthesiologists grade ≥ 3). Institutional ethical approval was obtained, and patients were counselled preoperatively with informed consent. Patients underwent colorectal resection using the Versius surgical system. Procedures were anticipated as hybrid operations (laparoscopic/robotic) consistent with a proof of concept/technical feasibility study. RESULTS: Main outcome measures included operative time, complication rates and pathological results. Thirty-two patients (15 men) underwent colorectal cancer resections. The mean age was 68 years (27-85 years). Estimated blood loss was 150 ml; range <100 to <500 ml. For right hemicolectomy, the average operative time was 221 min (183-323 min). The average console time was 111 min (64-213 min). For robotic anterior resection, the total operative time was on average 319 min (222-408 min) with an average console time of 204 min (85-242 min). Eight patients experienced Grade II morbidities (22%) with no serious morbidities and no mortalities. Mean return to bowel function was 2.9 days (1-6 days). The average length of stay was 5.3 days with a median of 4 days (2-20 days). All resections were R0 with an average lymph node yield of 20 nodes (8-46 nodes). CONCLUSION: Our initial experience with Versius demonstrates its safe adoption and implementation for colorectal resections.

Three-dimensional intracardiac echocardiography and pulmonary embolism.

BACKGROUND: Three-dimensional intracardiac echocardiography (3D ICE) with wide azimuthal elevation is a novel technique performed for assessment of cardiac anatomy and guidance of intracardiac procedures, being able to provide unique views with good spatial and temporal resolution. Complications arising from this invasive procedure and the value of 3D ICE in the detection and diagnosis of acute cardiovascular pathology are not comprehensively described. This case illustrates a previously unreported iatrogenic complication of clot displacement from the intra-vascular sheath upon insertion of a 3D ICE catheter and the value of 3D ICE in immediate diagnosis of clot in transit through the heart with pulmonary embolism. CASE PRESENTATION: We conducted a translational study of 3D ICE with wide azimuthal elevation to guide implantation of a left ventricular assist device (Impella CP®) in eight adult sheep. A large-bore 14 Fr central venous sheath was used to enable right atrial and right ventricular access for the intracardiac catheter. Insertion of the 3D ICE catheter was accompanied by a sudden severe cardiorespiratory deterioration in one animal. 3D ICE revealed a large highly mobile mass within the right heart chambers, determined to be a clot-in-transit. The diagnosis of pulmonary clot embolism resulting from the retrograde blood entry into the large-bore sheath introducer, rapid clot formation and consequent displacement into venous circulation by the ICE catheter was made. The sheep survived this life-threatening event following institution of cardiovascular support allowing completion of the primary research protocol. CONCLUSION: This report serves as a serious warning to the researchers and clinicians utilizing long large-bore sheath introducers for 3D ICE and illustrates the value of 3D ICE in detecting clot-in-transit within right heart chambers.

Five-year oncological outcomes after selective neoadjuvant radiotherapy for resectable rectal cancer.

Introduction: There is considerable variation in selection of patients for and type of neoadjuvant radiotherapy administered in the treatment of resectable rectal cancer. The aim of this study was to report outcomes for patients with resected rectal cancer from a unit with step-wise selection for surgery alone, short course radiotherapy (SCRT) or downstaging long course chemoradiotherapy (LCCRT). Material and methods: Cohort analysis of patients with rectal adenocarcinoma resected with curative intent between 2008 and 2012 at a specialist regional colorectal surgery center. The primary endpoints were local recurrence, metastatic recurrence, disease-free survival and overall survival. Exploratory uni- and multi-variable regression analyses were performed to identify predictive factors. Results: About 240 patients were treated by surgery alone, 90 patients received SCRT and 91 patients received LCCRT. Five-year local recurrence was 10.8% in the surgery alone group, 3.3% with SCRT and 18.7% with LCCRT. Metachronous distant metastasis was highest in the SCRT group (13.8% surgery alone, 25.6% SCRT, 15.4% LCCRT). Uni- and multi-variable regression analysis found that local and distant recurrence was attributable predominantly to adverse tumor biology. Conclusions: Patients selected for SCRT had a lower rate of local recurrence than patients selected for surgery alone, but were more likely to develop distant metastasis. There was no difference in overall survival. With low local recurrence rates, distant metastasis is the predominant risk for patients with resectable rectal cancer.

Composite Y Grafts From the Left Internal Mammary Artery: Current Considerations.

The use of composite coronary artery bypass grafts from the left internal mammary artery (LIMA) has increased over the last 20 years. Total arterial revascularisation can be achieved with two arterial conduits and is associated with a reduced risk of stroke. However, the traditional coronary bypass graft configurations of the in situ LIMA and aorto-coronary saphenous vein grafts remain as the mainstay of coronary bypass surgery in most centres. Concerns regarding composite Y grafts relate to (1) the adequacy of a single inflow for all coronary bypass grafts; (2) the risk of compromising the LIMA flow to the left anterior descending coronary artery; (3) the effects of competitive flow on graft patency; and (4) the use of sequential coronary anastomoses. The evidence upon which these concerns are based will be discussed along with the evidence relating to the use of the various second conduit options.

Enhanced recovery after surgery: Pain management.

Effective pain management is fundamental to enhanced recovery after surgery. Selection of strategies should be tailored to patient and operation. As well as improving the quality of recovery, effective analgesia reduces the host stress response, facilitates mobilization and allows resumption of oral intake. Multi-modal regimens combining paracetamol, non-steroidal anti-inflammatory agents where indicated, a potent opioid and a local anaesthetic technique achieve effective analgesia while limiting the dose and thereby side effects of any one agent.

Composite Y-Grafting Using the Left Internal Thoracic Artery: Survival and Angiography in 198 Cases.

BACKGROUND: Extended left internal thoracic artery (LITA) harvesting allows maximal grafting to the anterior and lateral walls with a single ITA conduit. This study evaluates outcomes following the use of a LITA Y graft as the primary grafting strategy. METHODS: Patients who underwent LITA composite Y-grafting (n=198) between 1995 and 2009 were identified from a cardiac surgical database. Follow-up (mean 13.1 years) was obtained by cross-reference with the state death registry and local cardiology databases. RESULTS: Operative mortality was zero in the 168 patients who underwent isolated CABG and was 3.5% overall. There were no episodes of perioperative myocardial infarction. Kaplan-Meier 10-year survival was 75.9%. Independent predictors of worse late survival were age, diabetes, chronic obstructive pulmonary disease and pre-existing left ventricular dysfunction. There were 53 episodes of post-discharge angiography at an average of 5.8 years post LITA Y grafting. Twenty cases of LITA Y graft failure were identified, predominantly affecting the free limb (n=15). The ratio of symptom driven angiography to Y graft failure increased over time. Eighteen patients required revascularisation, percutaneous intervention in 15 and reoperative coronary bypass in three. CONCLUSIONS: Left Internal Thoracic Artery Y grafting is a feasible revascularisation strategy with satisfactory outcomes. These are comparable to other arterial composite graft configurations. A LITA Y allows efficient conduit use without compromising the in situ LITA graft.

Efficacy of Intravenous Lidocaine for Postoperative Analgesia Following Laparoscopic Surgery: A Meta-Analysis.

BACKGROUND: Intravenous (IV) lidocaine has analgesic and anti-inflammatory properties. This study aims to evaluate the efficacy of IV lidocaine in controlling postoperative pain following laparoscopic surgery. METHODS: A meta-analysis of randomised controlled trials (RCTs) comparing IV lidocaine versus placebo/routine treatment for postoperative analgesia following laparoscopic surgery. The primary outcome was opiate requirement at 24 h. Secondary outcomes included cumulative opiate requirement, numerical pain scores (2, 12, 24, 48 h at rest and on movement), recovery indices (nausea and vomiting, length of stay, time until diet resumption, first flatus and bowel movement) and side effects (cardiac/neurological toxicity). Subgroup analyses were performed according to operation type and to compare IV lidocaine with intraperitoneal lidocaine. RESULTS: Fourteen RCTs with 742 patients were included. IV lidocaine was associated with a small but significant reduction in opiate requirement at 24 h compared with placebo/routine care. IV lidocaine was associated with reduced cumulative opiate requirement, reduced pain scores at rest at 2, 12 and 24 h, reduced nausea and vomiting and a shorter time until resumption of diet. The length of stay did not differ between groups. There was a low incidence of IV lidocaine-associated toxicity. In subgroup analyses, there was no difference between IV and intraperitoneal lidocaine in the measured outcomes. CONCLUSIONS: IV lidocaine has a multidimensional effect on the quality of recovery. IV lidocaine was associated with lower opiate requirements, reduced nausea and vomiting and a shorter time until resumption of diet. Whilst IV lidocaine appears safe, the optimal treatment regimen remains unknown. Statistical heterogeneity was high.

Saphenous vein to internal mammary artery end-to-end composite grafts for coronary artery bypass. Late follow-up.

BACKGROUND: Internal mammary artery (IMA) grafts provide equal or superior graft patency compared to other conduits. The IMA length limits extensive myocardial revascularisation with IMA grafts alone. This study aimed to determine the results of lengthening free IMAs with a short proximal segment of saphenous vein (SV) to enable more extensive myocardial revascularisation. METHODS: Patients (n=92) who underwent end-to-end composite SV-IMA grafts were followed up through cardiology and death register databases. RESULTS: The mean patient age was 57.5 years and median follow up 10.9 years. There was no perioperative mortality and 10-year survival was 89.6%. Thirty-one patients (34%) underwent repeat angiography at a median of 2.8 years postoperatively. The 10-year freedom from angiography showing SV segment occlusion was 89% with a median time to angiography of 2.3 years (nine patients). The number of distal anastomoses was the only independent predictor of SV segment occlusion HR per anastomosis=0.26 (p=0.01). In five sequential grafts to the circumflex and right coronary systems, the IMA portion of the graft remained patent following SV segment occlusion. CONCLUSIONS: Graft patency is improved by a greater number of coronary artery anastomoses.

ERK-MAPK signaling opposes Rho-kinase to promote endothelial cell survival and sprouting during angiogenesis.

Inhibition of ERK-MAPK signaling by expression of dominant-negative MEK1 in the tumor vasculature suppresses angiogenesis and tumor growth. In an organotypic tissue culture angiogenesis assay, ERK-MAPK inhibition during the migratory phase results in loss of bipolarity, detachment, and cell death of isolated endothelial cells and retraction of sprouting tubules. These effects are the consequence of upregulated Rho-kinase signaling. Transient inhibition of Rho-kinase rescues the effects of ERK-MAPK inhibition in vitro and in vivo, promotes sprouting, and increases vessel length in tumors. We propose a regulatory role of Rho-kinase by ERK-MAPK during angiogenesis that acts through the control of actomyosin contractility. Our data delineate a mechanism by which ERK-MAPK promotes endothelial cell survival and sprouting by downregulating Rho-kinase signaling.

Variation in colorectal cancer treatment and outcomes in Scotland: real world evidence from national linked administrative health data.

Background: Colorectal cancer (CRC) is the fourth most common type of cancer in the United Kingdom and the second leading cause of cancer death. Despite improvements in CRC survival over time, Scotland lags behind its UK and European counterparts. In this study, we carry out an exploratory analysis which aims to provide contemporary, population level evidence on CRC treatment and survival in Scotland. Methods: We conducted a retrospective population-based analysis of adults with incident CRC registered on the Scottish Cancer Registry (Scottish Morbidity Record 06 (SMR06)) between January 2006 and December 2018. The CRC cohort was linked to hospital inpatient (SMR01) and National Records of Scotland (NRS) deaths records allowing a description of their demographic, diagnostic and treatment characteristics. Cox proportional hazards regression models were used to explore the demographic and clinical factors associated with all-cause mortality and CRC specific mortality after adjusting for patient and tumour characteristics among people identified as early-stage and treated with surgery. Results: Overall, 32,691 (73%) and 12,184 (27%) patients had a diagnosis of colon and rectal cancer respectively, of whom 55% and 53% were early-stage and treated with surgery. Five year overall survival (CRC specific survival) within this cohort was 72% (82%) and 76% (84%) for patients with colon and rectal cancer respectively. Cox proportional hazards models revealed significant variation in mortality by sex, area-based deprivation and geographic location. Conclusions: In a Scottish population of patients with early-stage CRC treated with surgery, there was significant variation in risk of death, even after accounting for clinical factors and patient characteristics.

Pearls and Pitfalls of Epicardial Echocardiography for Implantation of Impella CP Devices in Ovine Models.

The Impella CP is a percutaneously inserted temporary left ventricular assist device used in clinical practice and in translational research into cardiogenic shock, perioperative cardiac surgery, acute cardiac failure and mechanical circulatory support. Fluoroscopic guidance is usually used for insertion of an Impella, thus limiting insertion to within catheterization laboratories. Transthoracic, transoesophageal and intracardiac echocardiography have been reported to guide Impella CP implantation with identified specific limitations stemming from the surgical, anatomical and equipment factors. We conducted translational prospective descriptive feasibility investigation as a part of two other hemodynamic Impella studies. It showed the successful application of epicardial echocardiographic scanning for implantation of Impella CP devices in ovine models, from which details of the technique and identified pitfalls are described with practical solutions for future investigators and clinicians. Many described findings are relevant to any other echocardiographic techniques when adequate imaging of the Impella and relevant anatomical structures is achievable.

Preventing Sheep Carotid Artery Spasm for Vascular Graft Surgery and Computed Tomography Angiography.

The development of small-diameter vascular grafts requires testing in large animal models before advancing to clinical trials. Vascular graft interposition implantation in sheep carotid arteries (CAs) is the most widely used model, but ovine CAs are prone to severe spasm following surgical manipulation, potentially impairing graft performance assessment. There is paucity in the literature on reducing sheep CA spasm using effective vasodilator therapeutic protocols. In this study, four healthy Merino cross White Suffolk wethers (1-2 years, 52.1 ± 0.8 kg) underwent CT angiography and CA graft surgery. CT angiography using iodinated contrast agent was performed with innominate artery access through the CA or ascending aortic arch access through the femoral artery. Sheep then underwent right CA sham surgery or left CA vascular graft implantation. A variety of vasodilators, including papaverine, sodium nitroprusside, verapamil, and their combination, were tested for preventing or treating CA spasms intraoperatively. Blood flow was reassessed immediately after CA surgery using CT angiography. The results showed that innominate artery access through the CA for CT angiography in sheep induced presurgical CA spasm with reduced arterial flow. Conversely, ascending aortic arch access through the femoral artery for CT angiography did not cause CA spasm and maintained arterial flow. During CA graft surgery, surgical trauma induced CA spasm, which was prevented by localized intra-arterial administration of vasodilators papaverine hydrochloride and verapamil before significant surgical manipulation.

Cellular heterogeneity of pluripotent stem cell-derived cardiomyocyte grafts is mechanistically linked to treatable arrhythmias.

Preclinical data have confirmed that human pluripotent stem cell-derived cardiomyocytes (PSC-CMs) can remuscularize the injured or diseased heart, with several clinical trials now in planning or recruitment stages. However, because ventricular arrhythmias represent a complication following engraftment of intramyocardially injected PSC-CMs, it is necessary to provide treatment strategies to control or prevent engraftment arrhythmias (EAs). Here, we show in a porcine model of myocardial infarction and PSC-CM transplantation that EAs are mechanistically linked to cellular heterogeneity in the input PSC-CM and resultant graft. Specifically, we identify atrial and pacemaker-like cardiomyocytes as culprit arrhythmogenic subpopulations. Two unique surface marker signatures, signal regulatory protein α (SIRPA)+CD90-CD200+ and SIRPA+CD90-CD200-, identify arrhythmogenic and non-arrhythmogenic cardiomyocytes, respectively. Our data suggest that modifications to current PSC-CM-production and/or PSC-CM-selection protocols could potentially prevent EAs. We further show that pharmacologic and interventional anti-arrhythmic strategies can control and potentially abolish these arrhythmias.

Waist circumference and waist/hip ratio are better predictive risk factors for mortality and morbidity after colorectal surgery than body mass index and body surface area.

OBJECTIVES: To determine whether body fat distribution, measured by waist circumference (WC) and waist/hip ratio (WHR), is a better predictor of mortality and morbidity after colorectal surgery than body mass index (BMI) or body surface area (BSA). BACKGROUND: Obesity measured by BMI is not a consistent risk factor for postoperative mortality and morbidity after abdominal surgery. Studies in metabolic and cardiovascular diseases have shown WC and WHR to be better outcome predictors than BMI. METHODS: A prospective multicenter international study was conducted among patients undergoing elective colorectal surgery. The WHR, BMI, and BSA were derived from body weight, height, and waist and hip circumferences measured preoperatively. Uni- and multivariate analyses were performed to identify risk factors for postoperative outcomes. RESULTS: A total of 1349 patients (754 men) from 38 centers in 11 countries were included. Increasing WHR significantly increased the risk of conversion [odds ratio (OR) = 15.7, relative risk (RR) = 4.1], intraoperative complications (OR = 11.0, RR = 3.2), postoperative surgical complications (OR = 7.7, RR = 2.0), medical complications (OR = 13.2, RR = 2.5), anastomotic leak (OR = 13.7, RR = 3.3), reoperations (OR = 13.3, RR = 2.9), and death (OR = 653.1, RR = 21.8). Both BMI (OR = 39.5, RR = 1.1) and BSA (OR = 4.9, RR = 3.1) were associated with an increased risk of abdominal wound complication. In multivariate analysis, the WHR predicted intraoperative complications, conversion, medical complications, and reinterventions, whereas BMI was a risk factor only for abdominal wall complications; BSA did not reach significance for any outcome. CONCLUSIONS: The WHR is predictive of adverse events after elective colorectal surgery. It should be used in routine clinical practice and in future risk-estimating systems.

RalGDS is required for tumor formation in a model of skin carcinogenesis.

To investigate the role of signaling by the small GTPase Ral, we have generated mice deficient for RalGDS, a guanine nucleotide exchange factor that activates Ral. We show that RalGDS is dispensable for mouse development but plays a substantial role in Ras-induced oncogenesis. Lack of RalGDS results in reduced tumor incidence, size, and progression to malignancy in multistage skin carcinogenesis, and reduced transformation by Ras in tissue culture. RalGDS does not appear to participate in the regulation of cell proliferation, but instead controls survival of transformed cells. Experiments performed in cells isolated from skin tumors suggest that RalGDS mediates cell survival through the activation of the JNK/SAPK pathway. These studies identify RalGDS as a key component in Ras-dependent carcinogenesis in vivo.

Delivery of Cardioactive Therapeutics in a Porcine Myocardial Infarction Model.

Myocardial infarction is one of the leading causes of death and disability worldwide, and there is an urgent need for novel cardioprotective or regenerative strategies. An essential component of drug development is determining how a novel therapeutic is to be administered. Physiologically relevant large animal models are of critical importance in assessing the feasibility and efficacy of various therapeutic delivery strategies. Due to their similarities to humans in cardiovascular physiology, coronary vascular anatomy, and heart weight to body weight ratio, swine is one of the preferred species in the preclinical evaluation of new therapies for myocardial infarction. The present protocol describes three methods of administering cardioactive therapeutic agents in a porcine model. After percutaneously induced myocardial infarction, female landrace swine received treatment with novel agents through either: (1) thoracotomy and transepicardial injection, (2) catheter-based transendocardial injection, or (3) intravenous infusion via jugular vein osmotic minipump. The procedures employed for each technique are reproducible, resulting in reliable cardioactive drug delivery. These models can be easily adapted to suit individual study designs, and each of these delivery techniques can be used to investigate a variety of possible interventions. Therefore, these methods are a useful tool for translational scientists pursuing novel biological approaches in cardiac repair following myocardial infarction.