The impact of expert by experience involvement in teaching in a DClinPsych programme; for trainees and experts by experience

INTRODUCTION

There is a growing acknowledgement of the value of creating partnerships between those delivering and those accessing health services. Less is known about this in the context of clinical psychology doctoral training programmes. This study explores the models of involvement of experts by experience (EbEs) in teaching on a DClinPsych course in England; the impact of this both for EbEs and trainee clinical psychologists and whether improvements are required to better meet their needs.

METHODS

An audit of current involvement was conducted by reviewing course records. Two survey questionnaires designed around commonly used frameworks of participation and reflective learning were completed by EbEs and trainees. Thematic Analysis was used to evaluate the written feedback from the surveys.

RESULTS

Records of current EbE involvement were found to be lacking in detail and sometimes missing. Key themes extrapolated from the surveys highlighted the importance of EbE involvement in supporting the wellbeing of EbEs and the learning experiences of trainees.

CONCLUSIONS

Recommendations with regard to the processes for future involvement of EbEs in teaching are put forward.

PATIENT OR PUBLIC CONTRIBUTION

A carer of a service user was consulted about the design of the participant information sheet, consent form and the survey questionnaire which was sent to the EbEs. A trainee clinical psychologist was also consulted to provide a trainee perspective on the above forms and the survey questionnaire that was sent to trainees. Further to this, the first author's supervisor identifies as a user of physical and mental health services and provided continued supervision and support regarding the direction of the study including the research questions, design, methodology and interpretation of results.

Exploring hepatitis C virus testing and treatment engagement over time in Melbourne, Australia: a study protocol for a longitudinal cohort study (EC-Experience Cohort study)

INTRODUCTION

The advent of direct acting antiviral therapy for hepatitis C virus (HCV) means the elimination of HCV is possible but requires sustained effort to achieve. Between 2016 and 2019, 44% of those living with HCV were treated in Australia. However, treatment uptake has declined significantly. In Australia, people who inject drugs (PWID) are the population most at risk of HCV acquisition. Eliminating HCV in Australia will require nuanced understanding of the barriers to HCV treatment experienced by PWID and tailored interventions to address these barriers. The EC-Experience Cohort study aims to explore the barriers and enablers reported by PWID to engagement in HCV care.

METHODS AND ANALYSIS

The EC-Experience Cohort study is a prospective cohort of PWID, established in Melbourne, Australia in 2018. Participants are assigned into three study groups: (1) those not currently engaged in HCV testing; (2) those diagnosed with HCV but not currently engaged in treatment and (3) those completed treatment. Participants complete a total of four interviews every 6 months across an 18-month study period. Predictors of experience of key outcome events along the HCV care cascade will be explored over time.

ETHICS AND DISSEMINATION

Ethical approval for the EC-Experience Cohort study was obtained by the Alfred Hospital Ethics Committee in Melbourne, Australia (Project Number: HREC/16/Alfred/164). All eligible participants are assessed for capacity to consent and partake in a thorough informed consent process. Results from the EC-Experience Cohort study will be disseminated via national and international scientific and public health conferences and peer-reviewed journal publications. Data from the EC-Experience Cohort study will improve the current understanding of the barriers to HCV care for PWID and guide the tailoring of service provision for specific subgroups. Understanding the barriers and how to increase engagement in care of PWID is critical to achieve HCV elimination goals.

Distinct circulating cytokine levels in patients with angiography-proven coronary artery disease compared to disease-free controls

Background

Systemic inflammation has a critical role in the development of coronary artery disease (CAD). Identification of inflammatory pathways may provide a platform for novel therapeutic approaches.

Purpose

We sought to determine whether there are differences in circulating cytokine profiles between patients with CAD and disease-free controls.

Methods

Study population consisted of 458 patients who underwent diagnostic invasive coronary angiography for clinical indications. Altogether 312 patients had angiographically significant CAD whereas 146 had no angiographically-detected coronary atherosclerosis. We measured the serum concentrations of 48 circulating cytokines.

Results

Patients with CAD had increased levels of interleukin-1 receptor antagonist (IL-1-RA), interleukin-2 receptor alpha (IL-2Rα), IL-3, IL-4, IL-6, IL-9, IL-10, IL-16, IL-17, IL-18, granulocyte-macrophage colony-stimulating factor (GM-CSF), platelet-derived growth factor-BB (PDGF-BB), macrophage inflammatory protein-1-beta (MIP-1-β), tumor necrosis factor-alpha (TNF-α), TNF-β, cutaneous T-cell-attracting chemokine (CTACK), growth regulated oncogene alpha (GRO-α), hepatocyte growth factor (HGF), interferon alpha-2 (IFNα-2), leukemia inhibitory factor (LIF), macrophage colony-stimulating factor (M-CSF), macrophage migration inhibitory factor (MIF), monokine induced by gamma interferon (MIG), beta-nerve growth factor (β-NGF), stem cell factor (SCF) and stromal cell-derived factor 1 alfa (SDF1α). On a logistic multivariate regression model adjusted with age, sex, hypertension and treatment for diabetes, increased levels of IL-4 (p=0.027, OR 1.090), IL-9 (p=0.000, OR 1.013), IL-17 (p=0.011, OR 1.005), CTACK (p=0.008, OR 1.001), MIP-1-β (p=0.004, OR 1.006), GRO-α (p=0.008, OR 1.004), TNF-α (p=0.019, OR 1.011) were independently associated with atherosclerosis.

Conclusions

Patients with CAD have distinct circulating cytokine profiles compared to disease-free controls. Based on these findings, certain cytokines may have a pivotal role in the development of atherosclerotic cardiovascular disease and cytokine-mediated pathway appear as a promising target for cardiovascular drug development.

Funding Acknowledgement

Type of funding source: Foundation. Main funding source(s): The Finnish Medical Foundation, Helsinki, Finland; The Finnish Foundation for Cardiovascular Research, Helsinki, Finland

Time-gated luminescence imaging for background free in vivo tracking of single circulating tumor cells

Fluorescence imaging is severely limited by the background and autofluorescence of tissues for in vivo detection of circulating tumor cells (CTCs). Time-gated luminescence (TGL) imaging, in combination with luminescent probes that possess hundreds of microsecond emission lifetimes, can be used to effectively suppress this background, which has predominantly nanosecond lifetimes. This Letter demonstrates the feasibility of TGL imaging using luminescent probes for the in vivo real time imaging and tracking of single CTCs circulating freely in the blood vessels with higher accuracy given by substantially higher signal-to-noise ratio. The luminescent probe used in this Letter was a commercial Eu³⁺ chelate (EuC) nanosphere with a super-long lifetime of near 800 µs, which enabled TGL imaging to achieve background-free detection with ∼5 times higher SNR versus steady state. Phantom and in vivo mouse studies indicated that EuC labeled tumor cells moving in medium or bloodstream at the speed of 1-2 mm/s could be captured in real time.

Perspectives on the Phase 0 clinical trial of microdose administration of ABY-029 for fluorescence guided surgery: Stability testing

ABY-029, an anti-epidermal growth factor receptor (EGFR) Affibody molecule labeled with IRDye 800CW, has been used in three Phase 0 microdosing clinical trials for fluorescence guided surgery. In May of 2019, the clinical trials were put on hold because the ABY-029 produced under Good Manufacturing Practices (GMP) for human administration had come to the end of term in which the drug product was known to be stable. Stability testing was halted due to limitations in supply of a suitable reference standard and a required test product being discontinued from commercial sale. In order to complete the remaining patients in the three clinical trials, new stability tests were developed and the GMP batch of ABY-029 drug product tested under the new protocols. The GMP batch of ABY-029 passed all stability tests under the new protocols and the Federal Drug Administration (FDA) has given permission to complete the remaining patients with stability testing of ABY-029 performed for each patient. The tests developed and used to test ABY-029 drug product stability are described here.

2227Limited impact of concomitant coronary artery by-pass grafting on long-term outcomes after surgical aortic valve replacement: a nationwide propensity matched study

Objective

Coronary artery disease is a common comorbidity of aortic stenosis. Addition of coronary artery by-pass grafting (CABG) to surgical aortic valve replacement (SAVR) is viable solution for treating both. Modern era impact of concomitant CABG to long-term outcomes is however inadequately known. We set out to study long-term outcomes of patients with or without CABG added to SAVR.

Methods

Patients (excluding infective endocarditis) aged ≥50 years with isolated first-time SAVR with or without CABG in Finland between 2004–2014 (n=7060) were retrospectively studied using nationwide registries. Propensity score matching (1:1) was used to identify patients with comparable baseline features (n=2188 with and n=2188 without concomitant CABG). Outcomes were 10-year all-cause mortality, stroke, major bleeding and myocardial infarction. Median follow-up was 6.1 years.

Results

In matched population mortality after SAVR was comparable with or without CABG (31.0% vs. 32.7%; HR 1.05; CI 0.93–1.20; p=0.428). However, if CABG was performed solely with venous grafts mortality was higher (35.9%; HR 1.21; CI 1.02–1.43; p=0.030 vs. no-CABG). Myocardial infarction was more common in patients with CABG (13.4% vs. 6.9%; HR 1.62; CI 1.22–2.17; p=0.0008). Occurrence of stroke was comparable with or without CABG (15.1% vs. 13.5%; p=0.933). Rate on any major bleeding was also comparable (20.0% with vs. 21.9% without CABG; p=0.496). Gastrointestinal (8.1% vs. 10.3%; p=0.978) and intracranial bleeds (6.0% vs. 5.5%; p=0.383) were also comparable between study groups.

Conclusions

Matched patients with or without concomitant CABG had comparable long-term mortality, stroke and major bleeding rates after SAVR. Our results suggest that successful concomitant CABG has limited impact on long-term outcomes after SAVR.

Acknowledgement/Funding

Finnish Cardiac Society, Finnish Cultural Foundation, Governmental VTR-funding

Location-Specific Comparison Between a 3D In-Stent Restenosis Model and Micro-CT and Histology Data from Porcine In Vivo Experiments

Background

Coronary artery restenosis is an important side effect of percutaneous coronary intervention. Computational models can be used to better understand this process. We report on an approach for validation of an in silico 3D model of in-stent restenosis in porcine coronary arteries and illustrate this approach by comparing the modelling results to in vivo data for 14 and 28 days post-stenting.

Methods

This multiscale model includes single-scale models for stent deployment, blood flow and tissue growth in the stented vessel, including smooth muscle cell (SMC) proliferation and extracellular matrix (ECM) production. The validation procedure uses data from porcine in vivo experiments, by simulating stent deployment using stent geometry obtained from micro computed tomography (micro-CT) of the stented vessel and directly comparing the simulation results of neointimal growth to histological sections taken at the same locations.

Results

Metrics for comparison are per-strut neointimal thickness and per-section neointimal area. The neointimal area predicted by the model demonstrates a good agreement with the detailed experimental data. For 14 days post-stenting the relative neointimal area, averaged over all vessel sections considered, was 20 ± 3% in vivo and 22 ± 4% in silico. For 28 days, the area was 42 ± 3% in vivo and 41 ± 3% in silico.

Conclusions

The approach presented here provides a very detailed, location-specific, validation methodology for in silico restenosis models. The model was able to closely match both histology datasets with a single set of parameters. Good agreement was obtained for both the overall amount of neointima produced and the local distribution. It should be noted that including vessel curvature and ECM production in the model was paramount to obtain a good agreement with the experimental data.

Electronic supplementary material

The online version of this article (10.1007/s13239-019-00431-4) contains supplementary material, which is available to authorized users.

Population-based study of anastomotic stricture rates after minimally invasive and open oesophagectomy for cancer

Background

The population‐based incidence of anastomotic stricture after minimally invasive oesophagectomy (MIO) and open oesophagectomy (OO) is not known. The aim of this study was to compare rates of anastomotic stricture requiring dilatation after the two approaches in an unselected cohort using nationwide data from Finland and Sweden.

Methods

All patients who had MIO or OO for oesophageal cancer between 2007 and 2014 were identified from nationwide registries in Finland and Sweden. Outcomes were the overall rate of anastomotic stricture and need for single or repeated (3 or more) dilatations for stricture within the first year after surgery. Multivariable Cox regression provided hazard ratios (HRs) with 95 per cent confidence intervals, adjusted for age, sex, co‐morbidity, histology, stage, year, country, hospital volume, length of hospital stay and readmissions.

Results

Some 239 patients underwent MIO and 1430 had an open procedure. The incidence of strictures requiring one dilatation was 16·7 per cent, and that for strictures requiring three or more dilatations was 6·6 per cent. The HR for strictures requiring one dilatation was not increased after MIO compared with that after OO (HR 1·19, 95 per cent c.i. 0·66 to 2·12), but was threefold higher for repeated dilatations (HR 3·25, 1·43 to 7·36). Of 18 strictures following MIO, 14 (78 per cent) occurred during the first 2 years after initiating this approach.

Conclusion

The need for endoscopic anastomotic dilatation after oesophagectomy was common, and the need for repeated dilatation was higher after MIO than following OO. The increased risk after MIO may reflect a learning curve.

Measuring microdose ABY-029 fluorescence signal in a primary human soft-tissue sarcoma resection

Microdose administration of ABY-029, an anti-epidermal growth factor receptor Affibody molecule conjugated to IRDye 800CW, is being studied in a Phase 0 trial for resection of soft-tissue sarcomas. The excised tissue of a single patient in the microdose administration group was imaged with both a wide-field fluorescence surgical system and a flat-bed scanning fluorescence imaging system. Here the resultant fluorescence from a breadloaf section of the primary tumor specimen and six region-specific tissue samples collected from that breadloaf are compared using these two imaging systems - a flatbed, black-box, fluorescence scanning system, the Odyssey CLx, and a open-air, wide-field, pre-clinical surgical imaging system, the Solaris. Florescence signal is compared using a variety of methods including: mean, standard deviation, variance, tumor-to-background ratio, biological-variance ratio, and contrast-to-noise ratio. The images produced from the Odyssey scanner have higher signal variance but more accurately represent the EGFR expression in small tissue sections. The Solaris system has higher depth sensitivity and volume averaging, and as such has lower signal variation and higher contrast-to-noise ratio.

Comparison of detection sensitivity of near infrared (NIR) surgical imaging systems using a connective tissue phantom model

Many tumors for which fluorescence guided surgery (FGS) has been developed are surface tumors, where direct visualization by the surgeon is straightforward. On the other hand, cancers such as soft-tissue sarcomas, are present at a subsurface level. Resection of these sub-surface tumors is performed using 'wide local excision' where a single, complete mass is removed with an intact zone of normal tissue (~ 1 cm 'margin'). We used a phantom model for sarcoma with near infrared fluorophore IRDye800 CW that defined different tissue properties. We compare the detection sensitivity of two commercially available near infrared (NIR) surgical imaging systems, Solaris (Perkin Elmer) and SPY PHI (Novadaq) using the phantom models of sarcoma. We also determine targeted fluorescence signal on both systems for blinded surgical phantom dissection by a surgeon. The fluorescence intensities are higher for Solaris than for SPY-PHI. On average, the fluorescence increased with an increase in intralipid concentration and decreased with an increase in blood concentration. The depth of imaging was higher for Solaris than for SPY PHI. Using the target values, the surgeon successfully dissected all phantoms using Solaris. Using fat phantoms for SPY PHI, the surgeon cut through four out of the total. Further improvement in FGS will improve cancer recurrence and morbidity.

Optimizing Glioma Detection Using an EGFR-Targeted Fluorescent Affibody

Since many types of cancers overexpress EGFR, this surface receptor has been used as a target for therapy or diagnosis of malignant disease. Uptake kinetics of EGFR-targeted fluorescent Affibody (ABY-029) were studied with a view toward optimizing efficacy of tumor detection in a glioma as a function of both delivered dose and concurrent administration of unlabeled cetuximab (an EGFR antagonist). U251 glioma cells were inoculated in brain of nude rats, and the fluorescence from each brain was analyzed after the administration of ABY-029. Although cetuximab was able to systematically block ABY-029 binding to EGFR in a dose-dependent manner in cell culture, no influence on the tumor-to-normal brain contrast was seen when unlabeled cetuximab was administered prior to ABY-029. Ex vivo imaging of ABY-029 fluorescence showed increasing values of the tumor-to-normal brain ratio with an increasing injected dose. A saturation value was obtained at a dose of 245 μg kg^-1 which represents a 10-fold increase over a "microdose" value. According to FDA, the microdose of protein products is considered ≤30 nanomoles due to its difference in molecular weight as compared to synthetic drugs. This observation indicates that glioma detection will be optimal if the ABY-029 dose exceeds the "microdose" value.

Observation of short wavelength infrared (SWIR) Cherenkov emission

Cherenkov emission induced by external beam radiation from a clinical linear accelerator has been shown in preclinical molecular imaging and clinical imaging. The broad spectrum Cherenkov emission should have a short wavelength infrared (SWIR, 1000-1700 nm) component, as predicted theoretically. To the best of our knowledge, this Letter is the first experimental observation of this SWIR Cherenkov emission induced by external beam radiation. The measured spectrum of SWIR Cherenkov emission matches the theoretical prediction, with a fluence rate near one-third of the visible and near-infrared red emissions (Vis-NIR, 400-900 nm). Imaging in water-based phantoms and biological tissues indicates that there is a sufficient fluence rate for radiotherapy dosimetry applications. The spatial resolution is improved approximately 5.3 times with SWIR Cherenkov emission detection versus Vis-NIR Cherenkov emission, which provides some improvement in the potential for higher resolution Cherenkov emission dosimetry and molecular sensing during clinical radiotherapy by imaging with SWIR wavelengths.

Assessing daylight & low-dose rate photodynamic therapy efficacy, using biomarkers of photophysical, biochemical and biological damage metrics in situ

BACKGROUND

Sunlight can activate photodynamic therapy (PDT), and this is a proven strategy to reduce pain caused byconventional PDT treatment, but assessment of this and other alternative low dose rate light sources, and their efficacy, has not been studied in an objective, controlled pre-clinical setting. This study used three objective assays to assess the efficacy of different PDT treatment regimens, using PpIX fluorescence as a photophysical measure, STAT3 cross-linking as a photochemical measure, and keratinocyte damage as a photobiological measure.

METHODS

Nude mouse skin was used along with in vivo measures of photosensitizer fluorescence, keratinocyte nucleus damage from pathology, and STAT3 cross-linking from Western blot analysis. Light sources compared included a low fluence rate red LED panel, compact fluorescent bulbs, halogen bulbs and direct sunlight, as compared to traditional PDT delivery with conventional and fractionated high fluence rate red LED light delivery.

RESULTS

Of the three biomarkers, two had strong correlation to the PpIX-weighted light dose, which is calculated as the product of the treatment light dose (J/cm²) and the normalized PpIX absorption spectra. Comparison of STAT3 cross-linking to PpIX-weighted light dose had an R=0.74, and comparison of keratinocyte nuclear damage R=0.70. There was little correlation to PpIX fluorescence. These assays indicate most of the low fluence rate treatment modalities were as effective as conventional PDT, while fractionated PDT showed the most damage.

CONCLUSIONS

Daylight or artificial light PDT provides an alternative schedule for delivery of drug-light treatment, and this pre-clinical assay demonstrated that in vivo assays of damage could be used to objectively predict a clinical outcome in this altered delivery process.

Fluorescent Affibody Molecule Administered In Vivo at a Microdose Level Labels EGFR Expressing Glioma Tumor Regions

Purpose

Fluorescence guidance in surgical oncology provides the potential to realize enhanced molecular tumor contrast with dedicated targeted tracers, potentially with a microdose injection level. For most glioma tumors, the blood brain barrier is compromised allowing some exogenous drug/molecule delivery and accumulation for imaging. The aberrant overexpression and/or activation of epidermal growth factor receptor (EGFR) is associated with many types of cancers, including glioblastoma, and so the use of a near-infrared (NIR) fluorescent molecule targeted to the EGFR receptor provides the potential for improving tumor contrast during surgery. Fluorescently labeled affibody molecule (ABY-029) has high EGFR affinity and high potential specificity with reasonably fast plasma clearance. In this study, ABY-29 was evaluated in glioma versus normal brain uptake from intravenous injection at a range of doses, down to a microdose injection level.

Procedure

Nude rats were inoculated with the U251 human glioma cell line in the brain. Tumors were allowed to grow for 3–4 weeks. ABY-029 fluorescence ex vivo imaging of brain slices was acquired at different time points (1–48 h) and varying injection doses from 25 to 122 μg/kg (from human protein microdose equivalent to five times microdose levels).

Results

The tumor was most clearly visualized at 1-h post-injection with 8- to 16-fold average contrast relative to normal brain. However, the tumor still could be identified after 48 h. In all cases, the ABY-029 fluorescence appeared to localize preferentially in EGFR-positive regions. Increasing the injected dose from a microdose level to five times, a microdose level increased the signal by 10-fold, and the contrast was from 8 to 16, showing that there was value in doses slightly higher than the microdose restriction. Normal tissue uptake was found to be affected by the tumor size, indicating that edema was a likely factor affecting the expected tumor to normal tissue contrast.

Conclusion

These results suggest that the NIR-labeled affibody molecules provide an excellent potential to increase surgical visualization of EGFR-positive tumor regions.

Surgical management of complicated and medically refractory inflammatory bowel disease during pregnancy

AIM

The medical management of inflammatory bowel disease (IBD) in pregnancy and the puerperium is well defined. Data on surgical management of complicated IBD in this setting are lacking. This study aimed to determine the optimal surgical strategy for medically refractory IBD during pregnancy and the puerperium.

METHOD

Three databases were systematically reviewed to identify all published series or case reports of women undergoing surgery for Crohn's disease (CD) or ulcerative colitis (UC) while pregnant or during the puerperium.

RESULTS

Thirty-two papers were identified, including 86 patients. Nearly one-fifth (18%) of cases were de novo presentations and intervention was required at all stages of pregnancy. UC refractory to medical treatment and perforated small bowel CD were the commonest indications for surgery. Operations used included colectomy, colectomy with mucous fistula and Turnbull-blowhole colostomy for complicated UC and open or laparoscopic small bowel resection with stoma formation for CD. Surgical intervention during the third trimester universally resulted in the onset of labour. Endoscopic and radiological interventions were rarely employed. In studies after 1980 there was no maternal or foetal mortality but there was an almost 50% preterm delivery rate.

CONCLUSION

Surgical management of complicated IBD during pregnancy and the puerperium needs to be tailored to disease severity, the type of complications and foetal status. It should involve gastroenterologists, colorectal surgeons, obstetricians and neonatal specialists in a multidisciplinary manner within a single unit.

Comparing desferrioxamine and light fractionation enhancement of ALA-PpIX photodynamic therapy in skin cancer

Background:

Aminolevulinic acid (ALA)-based photodynamic therapy (PDT) provides selective uptake and conversion of ALA into protoporphyrin IX (PpIX) in actinic keratosis and squamous cell carcinoma, yet large response variations in effect are common between individuals. The aim of this study was to compare pre-treatment strategies that increase the therapeutic effect, including fractionated light delivery during PDT (fPDT) and use of iron chelator desferrioxamine (DFO), separately and combined.

Methods:

Optical measurements of fluorescence were used to quantify PpIX produced, and the total amount of PpIX photobleached as an implicit measure of the photodynamic dose. In addition, measurements of white light reflectance were used to quantify changes in vascular physiology throughout the PDT treatment.

Results:

fPDT produced both a replenishment of PpIX and vascular re-oxygenation during a 2 h dark interval between the first and second PDT light fractions. The absolute photodynamic dose was increased 57% by fPDT, DFO and their combination, as compared with PDT group (from 0.7 to 1.1). Despite that light fractionation increased oedema and scab formation during the week after treatment, no significant difference in long-term survival has been observed between treatment groups. However, outcomes stratified on the basis of measured photodynamic dose showed a significant difference in long-term survival.

Conclusions:

The assessment of implicit photodynamic dose was a more significant predictor of efficacy for ALA-PDT skin cancer treatments than prescription of an enhanced treatment strategy, likely because of high individual variation in response between subjects.

Logarithmic intensity compression in fluorescence guided surgery applications

The use of fluorescence video imaging to guide surgery is rapidly expanding, and improvements in camera readout dynamic range have not matched display capabilities. Logarithmic intensity compression is a fast, single-step mapping technique that can map the useable dynamic range of high-bit fluorescence images onto the typical 8-bit display and potentially be a variable dynamic contrast enhancement tool. We demonstrate a ∼4.6  times improvement in image quality quantified by image entropy and a dynamic range reduction by a factor of ∼380 by the use of log-compression tools in processing in vivo fluorescence images.

Advancing Molecular-Guided Surgery through probe development and testing in a moderate cost evaluation pipeline

Molecular guided oncology surgery has the potential to transform the way decisions about resection are done, and can be critically important in areas such as neurosurgery where the margins of tumor relative to critical normal tissues are not readily apparent from visual or palpable guidance. Yet there are major financial barriers to advancing agents into clinical trials with commercial backing. We observe that development of these agents in the standard biological therapeutic paradigm is not viable, due to the high up front financial investment needed and the limitations in the revenue models of contrast agents for imaging. The hypothesized solution to this problem is to develop small molecular biologicals tagged with an established fluorescent reporter, through the chemical agent approval pathway, targeting a phase 0 trials initially, such that the initial startup phase can be completely funded by a single NIH grant. In this way, fast trials can be completed to de-risk the development pipeline, and advance the idea of fluorescence-guided surgery (FGS) reporters into human testing. As with biological therapies the potential successes of each agent are still moderate, but this process will allow the field to advance in a more stable and productive manner, rather than relying upon isolated molecules developed at high cost and risk. The pathway proposed and tested here uses peptide synthesis of an epidermal growth factor receptor (EGFR)-binding Affibody molecules, uniquely conjugated to IRDye 800CW, developed and tested in academic and industrial laboratories with well-established records for GMP production, fill & finish, toxicity testing, and early phase clinical trials with image guidance.

Pixel-based absorption correction for dual-tracer fluorescence imaging of receptor binding potential

Ratiometric approaches to quantifying molecular concentrations have been used for decades in microscopy, but have rarely been exploited in vivo until recently. One dual-tracer approach can utilize an untargeted reference tracer to account for non-specific uptake of a receptor-targeted tracer, and ultimately estimate receptor binding potential quantitatively. However, interpretation of the relative dynamic distribution kinetics is confounded by differences in local tissue absorption at the wavelengths used for each tracer. This study simulated the influence of absorption on fluorescence emission intensity and depth sensitivity at typical near-infrared fluorophore wavelength bands near 700 and 800 nm in mouse skin in order to correct for these tissue optical differences in signal detection. Changes in blood volume [1-3%] and hemoglobin oxygen saturation [0-100%] were demonstrated to introduce substantial distortions to receptor binding estimates (error > 30%), whereas sampled depth was relatively insensitive to wavelength (error < 6%). In response, a pixel-by-pixel normalization of tracer inputs immediately post-injection was found to account for spatial heterogeneities in local absorption properties. Application of the pixel-based normalization method to an in vivo imaging study demonstrated significant improvement, as compared with a reference tissue normalization approach.

Outcomes of asymptomatic anastomotic leaks found on routine postoperative water-soluble enema following anterior resection for cancer

BACKGROUND

The incidence and consequence of an anastomotic leak associated with low anterior resection for cancer mandates covering stoma in most cases. A water-soluble enema is often performed to assess anastomotic integrity prior to stoma reversal. The functional outcome following reversal in patients with occult radiologically detected leaks is poorly defined. The goal of the present study was to determine the functional outcome in patients with a radiologically detected anastomotic leak who subsequently underwent stoma reversal.

METHODS

This case control study used patients with and without radiologically detected occult anastomotic leak having undergone reversal of covering stomata. The study group was matched with controls for age, gender, procedure, tumor stage, and adjuvant/neoadjuvant therapy. Validated fecal incontinence quality of life (FIQL), Cleveland Clinic Fecal Incontinence Score (CCFIS), and the Memorial Sloan-Kettering Cancer Center (MSKCC) Bowel Function Index (BFI) were used. Patient satisfaction, medication use, and ancillary procedures prior to closure were also recorded.

RESULTS

Thirteen patients with radiologically detected occult anastomotic leaks and 13 matched controls were identified from a prospectively maintained database. The FIQL, CCFIS, and MSKCC BFI scores were significantly reduced in those with occult leaks. The mean number of radiological and surgical interventions was significantly greater in the patients with occult leaks. Antidiarrheal and bulking agent use, as well as patient satisfaction, were the same for both groups. Only one patient in the occult leak group would not undergo stoma reversal again.

CONCLUSIONS

Reversal of a defunctioning ileostomy in the presence of an occult radiological leak can be associated with poorer functional outcomes, but patient satisfaction is undiminished.

Simulation of oxygen transfer in stented arteries and correlation with in-stent restenosis

Computational models are used to study the combined effect of biomechanical and biochemical factors on coronary in-stent restenosis, which is a postoperative remodeling and regrowth pathology of the stented arteries. More precisely, we address numerical simulations, on the basis of Navier-Stokes and mass transport equations, to study the role of perturbed wall shear stresses and reduced oxygen concentration in a geometrical model reconstructed from a real porcine artery treated with a stent. Joining in vivo and in silico tools of investigation has multiple benefits in this case. On one hand, the geometry of the arterial wall and of the stent closely correspond to a real implanted configuration. On the other hand, the inspection of histological tissue samples informs us on the location and intensity of in-stent restenosis. As a result, we are able to correlate geometrical factors, such as the axial variation of the artery diameter and its curvature; the numerical quantification of biochemical stimuli, such as wall shear stresses; and the availability of oxygen to the inner layers of the artery, with the appearance of in-stent restenosis. This study shows that the perturbation of the vessel curvature could induce hemodynamic conditions that stimulate undesired arterial remodeling.

Fluorescent affibody peptide penetration in glioma margin is superior to full antibody

Object

Fluorescence imaging has the potential to significantly improve neurosurgical resection of oncologic lesions through improved differentiation between normal and cancerous tissue at the tumor margins. In order to successfully mark glioma tissue a fluorescent tracer must have the ability to penetrate through the blood brain barrier (BBB) and provide delineation in the tumor periphery where heterogeneously intact BBB may exist. In this study it was hypothesized that, due to its smaller size, fluorescently labeled anti-EGFR Affibody protein (∼7 kDa) would provide a more clear delineation of the tumor margin than would fluorescently labeled cetuximab, a full antibody (∼150 kDa) to the epidermal growth factor receptor (EGFR).

Methods

Cetuximab and anti-EGFR targeted Affibody were conjugated to two different fluorescent dyes (both emitting in the near-infrared) and injected intravenously into 6 athymic mice which were inoculated orthotopically with green fluorescent protein (GFP) expressing human U251 glioma cells. Each mouse was sacrificed at 1-h post injection, at which time brains were removed, snap frozen, sectioned and quantitatively analyzed for fluorescence distribution.

Results

Ex vivo analysis showed on average, nearly equal concentrations of cetuximab and Affibody within the tumor (on average Affibody made up 49±6% of injected protein), however, the cetuximab was more confined to the center of the tumor with Affibody showing significantly higher concentrations at the tumor periphery (on average Affibody made up 72±15% of injected protein in the outer 50 um of the tumor). Further ex vivo analysis of detection studies showed that the Affibody provided superior discrimination for differentiation of tumor from surrounding normal brain.

Conclusions

The present study indicates that fluorescently labeled anti-EGFR Affibody can provide significantly better delineation of tumor margins than a fluorescently labeled anti-EGFR antibody and shows considerable potential for guiding margin detection during neurosurgery.

Note: Measurements of fast electrons in the TORE-SUPRA tokamak by means of modified Cherenkov-type diamond detector

The Note reports on experimental studies of ripple born fast electrons within the TORE-SUPRA facility, which were performed by means of a modified measuring head equipped with diamond detectors designed especially for recording the electron-induced Cherenkov radiation. There are presented signals produced by fast electrons in the TORE-SUPRA machine, which were recorded during two experimental campaigns performed in 2010. Shapes of these electron-induced signals are considerably different from those observed during the first measurements carried out by the prototype Cherenkov probe in 2008. An explanation of the observed differences is given.