Anaemia in cardiac surgery - a retrospective review of a centre's experience with a pre-operative intravenous iron clinic

Pre-operative anaemia is associated with higher rates of transfusion and worse outcomes, including prolonged hospital stay, morbidity and mortality. Iron deficiency is associated with significantly lower haemoglobin levels throughout the peri-operative period and more frequent blood transfusion. Correction of iron stores before surgery forms part of the first pillar of patient blood management. We established a pre-operative anaemia clinic to aid identification and treatment of patients with iron deficiency anaemia scheduled for elective cardiac surgery. We present a retrospective observational review of our experience from January 2017 to December 2019. One-hundred and ninety patients received treatment with intravenous iron, a median of 21 days before cardiac surgery. Of these, 179 had a formal laboratory haemoglobin level measured before surgery, demonstrating a median rise in haemoglobin of 8.0 g.l^-1 . Patients treated with i.v. iron demonstrated a significantly higher incidence of transfusion (60%) compared with the non-anaemic cohort (22%) during the same time period, p < 0.001. Significantly higher rates of new requirement for renal replacement therapy (6.7% vs. 0.6%, p < 0.001) and of stroke (3.7% vs. 1.2%, p = 0.010) were also seen in this group compared with those without anaemia, although there was no significant difference in in-hospital mortality (1.6% vs. 0.8%, p = 0.230). In patients where the presenting haemoglobin was less than 130 g.l^-1 , but there was no intervention or treatment, there was no difference in rates of transfusion or of complications compared with the anaemic group treated with iron. In patients with proven iron deficiency anaemia, supplementation with intravenous iron showed only a modest effect on haemoglobin and this group still had a significantly higher transfusion requirement than the non-anaemic cohort. Supplementation with intravenous iron did not improve outcomes compared with patients with anaemia who did not receive intravenous iron and did not reduce peri-operative risk to non-anaemic levels. Questions remain regarding identification of patients who will receive most benefit, the use of concomitant treatment with other agents, and the optimum time frames for treatment in order to produce benefit in the real-world setting.

Long-term Survival with 18-Fluorodeoxyglucose Positron Emission Tomography-directed Therapy in Non-small Cell Lung Cancer with Synchronous Solitary Brain Metastasis

AIMS

At diagnosis, <1% of patients with non-small cell lung cancer (NSCLC) have synchronous solitary brain metastasis (SSBM). In prior cohorts without 18-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) staging, definitive treatment to intracranial and intrathoracic disease showed a 5-year overall survival (OS) of 11-21%. We investigated the long-term survival outcomes for patients with SSBM NSCLC, diagnosed in the FDG-PET/CT era and treated definitively with local therapies to both intracranial and intrathoracic sites of disease.

MATERIALS AND METHODS

This retrospective study assessed patients staged with FDG-PET/CT who received definitive lung and SSBM treatment from February 1999 to December 2017. A lung-molecular graded prognostic assessment (lung-molGPA) score was assigned for each patient using age, performance status score, and, where carried out, molecular status. Overall survival and progression-free survival (PFS) were calculated using Kaplan-Meier methods. Cox proportional hazard models determined OS and PFS prognostic factors.

RESULTS

Forty-nine patients newly diagnosed with NSCLC and SSBM had a median age of 63 years (range 34-76). The median follow-up of all patients was 3.9 years. Thirty-three patients (67%) had ≥T2 disease, 23 (47%) had ≥N2. At 2 years, 45% of first failures were intracranial only (95% confidence interval 30-59). At 3 and 5 years, OS was 45% (95% confidence interval 32-63) and 30% (95% confidence interval 18-51), respectively. In ≥N1 disease, 5-year OS was 34% (95% confidence interval 18-63). The 3- and 5-year PFS was 8% (95% confidence interval 3-22) and 0%, respectively. Higher lung-molGPA was associated with longer OS (hazard ratio 0.26, 95% confidence interval 0.11-0.61, P = 0.002). Higher lung-molGPA (hazard ratio 0.33, 95% confidence interval 0.15-0.71, P = 0.005) and lower N-stage (hazard ratio 1.56, 95% confidence interval 1.13-2.15, P = 0.007) were associated with longer PFS.

CONCLUSIONS

Definitive treatment of patients with NSCLC and SSBM staged with FDG-PET/CT can result in 5-year survivors, including those with ≥N1 disease.

Predictors of major bleeding following an acute coronary event: insights from a national study of 5,116 consecutive patients in clinical practice

Background

Major bleeding after acute coronary syndrome (ACS) predicts a poor outcome. Although predictors of major bleeding following ACS have been validated, these have been mostly in clinical trial populations and few contemporary analyses have been undertaken in clinical practise

Methods

Major bleeding was assessed in a national study of ACS and antiplatelet choice. A total of 5116 consecutive patients [Clopidogrel (n 2,491, 2011–13) and Ticagrelor (n 2,625, 2013–16)] were enrolled in 5 UK hospitals. Clinical outcomes were identified from a national coding database (n=59.5 million) with bleeding events tracked to 11 health care facilities. Bleed severity was independently adjudicated by 2 consultant cardiologists, blinded to antiplatelet, sequence and year. Bleeding events were categorised using BARC 3–5 and PLATO criteria. A logistic regression analysis was used to define independent predictors of bleeding.

Results

The median age was 68 (IQR57–78, 30.5%&gt;75), 34% were female. 39% underwent PCI and 13% coronary artery bypass surgery. Clinical outcome data was 100% complete. 1-year mortality was 12.9%. Of 1193 icd10 codes for bleeding or anaemia 165 (3.2%) and 193 (3.8%) patients were adjudicated to have suffered a BARC 3–5 and PLATO major bleeding respectively. Independent predictors common between PLATO major and BARC 3–5 bleeding, in the year following ACS, were CRUSADE score &gt;40 (OR 1.63, CI 1.1–2.4, p=0.008) moderate left ventricular systolic dysfunction (OR, 1.65, CI: 1.2–2.4, p=0.006), age (OR per year increase in age 1.03, CI 1.02–1.05, p&lt;0.001) and subsequent coronary artery bypass surgery (OR 2.6, CI 1.8–3.8, p&lt;0.001)

Conclusion

In a broad real-world population of ACS, CRUSADE score &gt;40, incorporating simple clinical and laboratory criteria, remained an independent predictor of major bleeding using 2 internationally recognised bleed criteria

Funding Acknowledgement

Type of funding source: Public Institution(s). Main funding source(s): Liverpool university hospitals; North-West Educational Cardiac Group

Hospital-Wide Medication Reconciliation Program: Error Identification, Cost-Effectiveness, and Detecting High-Risk Individuals on Admission

Background

Medication reconciliation (MR) on admission has potential to reduce negative patient outcomes. The objectives of this prospective observational study were to 1) measure the impact a hospital-wide MR program has on home medication error identification at hospital admission, 2) demonstrate cost-effectiveness of this program, and 3) identify risk factors placing individual patients at higher risk for medication discrepancies.

Methods

Technicians obtained medication histories on adult patients admitted to the hospital that managed their own medications. Frequency and type of medication errors were recorded. Cost avoidance estimations were determined based on expected adverse drug event rates. Logistic regression analysis was used to test for associations between medication errors and patient characteristics. Results were considered significant when p-value was less than 0.05.

Results

The study included 817 patients. Technicians recorded a mean of 6.1 medication discrepancies per patient (SD ± 0.4) and took 28.5 minutes (SD ± 1.2 minutes) to complete a medication history. Omission, commission, and dosing/frequency errors occurred in 82%, 59%, and 50% of medication histories, respectively. We estimated cost avoidance of $210.33 per patient with this program. Female gender, age, and high alert/risk medication use were linked to an increase in the likelihood of occurrence of a medication discrepancy.

Conclusion

This study validated the ability of a pharmacy technician to identify errors, demonstrated economic cost-effectiveness, provided new data on time to obtain a BPMH, and further identified factors that contribute to the occurrence of medication discrepancies. Potentially harmful medication discrepancies were identified frequently on admission. With further research, it may be possible to identify those at highest risk for home medication discrepancies upon admission.

Delivering Transcranial Direct Current Stimulation Away From Clinic: Remotely Supervised tDCS

INTRODUCTION

To demonstrate the broad utility of the remotely supervised transcranial direct current stimulation (RS-tDCS) protocol developed to deliver at-home rehabilitation for individuals with multiple sclerosis (MS).

METHODS

Stimulation delivered with the RS-tDCS protocol and paired with adaptive cognitive training was delivered to three different study groups of MS patients to determine the feasibility and tolerability of the protocol. The three studies each used consecutively increasing amounts of stimulation amperage (1.5, 2.0, and 2.5 mA, respectively) and session numbers (10, 20, and 40 sessions, respectively).

RESULTS

High feasibility and tolerability of the stimulation were observed for n = 99 participants across three tDCS pilot studies.

CONCLUSIONS

RS-tDCS is feasible and tolerable for MS participants. The RS-tDCS protocol can be used to reach those in locations without clinic access and be paired with training or rehabilitation in locations away from the clinic. This protocol could be used to deliver tDCS paired with training or rehabilitation activities remotely to service members and veterans.

Neutrophil Gelatinase-associated Lipocalin as a Marker of Postoperative Acute Kidney Injury Following Cardiac Surgery in Patients with Preoperative Kidney Impairment

INTRODUCTION

Acute kidney injury (AKI) is a serious complication of cardiac surgery. The current 'gold standard' for determining AKI is change in serum creatinine and urine output, however, this change occurs relatively late after the actual injury occurs. Identification of new biomarkers that detect early AKI is required. Recently, new biomarkers, such as the NephroCheck® Test and AKIRisk have also been tested and found to be good indicators of AKI. Neutrophil gelatinase-associated lipocalin (NGAL) has shown promise in paediatric patients but has displayed varied results in adult populations, particularly post cardiac surgery. The aim of this study was to assess the value of urinary NGAL as a biomarker of AKI in patients with pre-existing renal impairment (eGFR >15ml/min to eGFR<60ml/min).

METHODS

A post-hoc analysis of urinary NGAL concentrations from 125 patients with pre-existing kidney impairment, who participated in a randomised trial of haemofiltration during cardiac surgery, was undertaken. Urinary NGAL was measured using ELISA at baseline, post-operatively and 24 and 48 hours after surgery, and serum creatinine was measured pre and postoperatively and then at 24, 48, 72 and 96 hours as routine patient care. NGAL concentrations were compared in patients with and without AKI determined by changes in serum creatinine concentrations. A Kaplan-Meier plot compared survival for patients with or without AKI and a Cox proportional hazards analysis was performed to identify factors with the greatest influence on survival.

RESULTS

Following surgery, 43% of patients developed AKI (based on KDIGO definition). Baseline urinary NGAL was not found to be significantly different between patients that did and did not develop AKI. Urinary NGAL concentration was increased in all patients following surgery, regardless of whether they developed AKI and was also significant between groups at 24 (p=0.003) and 48 hours (p<0.0001). Urinary NGAL concentrations at 48 hours correlated with serum creatinine concentrations at 48 hours (r=0.477, p<0.0001), 72 hours (r=0.488, p<0.0001) and 96 hours (r=0.463, p<0.0001). Urinary NGAL at 48 hours after surgery strongly predicted AKI (AUC=0.76; P=0.0001). A Kaplan- Meier plot showed that patients with postoperative AKI had a significantly lower 7-year survival compared with those without AKI. Postoperative urinary NGAL at 48 hours >156ng/mL also strongly predicted 7-year survival. However, additive EuroSCORE, age, current smoking and post-operative antibiotics usage were distinctly significantly more predictive of 7-year survival as compared with postoperative urinary NGAL at 48 hours >156ng/mL.

CONCLUSIONS

Our study demonstrated that postoperative urinary NGAL levels at 48 hours postsurgery strongly predicts the onset or severity of postoperative AKI based on KDIGO classification in patients with preoperative kidney impairment and were also strongly related to 7-year survival.

Digital Outreach: Promoting a global understanding of antimicrobial resistance (AMR)

Technology allows educators to reach a global audience without amassing a large carbon footprint. The Skype in the Classroom programme from Microsoft enables me to spark curiosity and engage a wide range of students in dialogue to explore global issues, in particular, the threat of antimicrobial resistance, while supporting me to develop my skills as an educator. Through a multi-disciplinary approach, I employ Skype in the Classroom as a future-proof, powerful tool in our arsenal against the evolving microbial threat. We are not only responsible for teaching the next generation of scientists, but also the next generation of thought-leaders and professionals, who will work collaboratively towards our common goals.

Antimicrobial resistance is one of the grand challenges of the 21st century, and global connectivity is one of the best solutions to promoting better understanding of this threat. The Skype in the Classroom programme has allowed me to teach sessions to students in Norway, India, Brazil, Miami, Florida and Puerto Rico, with students ranging from 10 to 18 years old. I use skype and Teams to deliver online lessons in an accessible way, starting with the scope of the problem, covering the technical detail of how resistance emerges and is spread, and looking at some of the newest approaches to tackling AMR. Using a ‘challenge-based-learning’ approach, we discuss how different professionals and roles within society can contribute to the issue. This makes the class applicable to students with a wide range of backgrounds, including those without a keen interest in science.

The Great Ormond Street Hospital immunoadsorption method for ABO-incompatible heart transplantation: a practical technique

Traditionally, ABO-incompatible heart transplantation was accomplished using a plasma exchange technique to remove recipient plasma containing donor-incompatible anti-A/B isohaemagglutinins. However, this technique exposed patients to large volumes of allogeneic blood and blood products (up to three times the patient’s circulating volume). In 2018, we published the first reported case of an ABO-incompatible heart transplant using an intraoperative immunoadsorption technique which minimises the exposure to blood products by specifically targeting anti-A/B isohaemagglutinins. We have subsequently used this technique in all children undergoing ABO-incompatible heart transplantation and become convinced of its efficacy in this population while observing no adverse effects. This article outlines the practical details required to perform the technique in order to avoid hyperacute rejection.

MON-694 EDKA and MALA in the Setting of Severe Heart Failure and Acute Renal Failure, Due to SGLT2-i

Background: EDKA is a reported potential side effect of SGLT-2i that presents a unique challenge for diagnosis and management in the setting of HF and concurrent AKI. Literature encourages wide use of SGLT-2i’s, however this case demonstrates the need of proper evaluation before initiating therapy.

Case: A 53 year old male with PMH of T2DM, Atrial fibrillation, HFrEF, presented to the Emergency Dept after a week of confusion, nausea, vomiting, and diarrhea. These symptoms were presumed due to gastroenteritis and our patient continued working on his farm in the summer heat. Following 3 days of intractable vomiting, he began to develop confusion, took his medications and presented to the ED. He was on metformin and had recently started empagliflozin following a heart failure exacerbation. Upon arrival the patient was noted to have a severe AKI with Cr of 15, hyperkalemia with potassium of 7.7, Anion gap of 45, bicarbonate of 4. Lactic acid was noted to be 7.7 and BHB was later noted to be 10.5 with a serum blood glucose of 155.

Pt was determined to have Euglycemic Diabetic Ketoacidosis with an additional Metformin associated lactic acidosis. He was started on an insulin drip with a concurrent D20 infusion to minimize fluid intake. Dextrose was titrated up to maintain a goal BG of 150-180 while on a stable insulin rate of 5u/hour, while monitoring serum ketones to resolution of DKA. Due to excess fluid intake he required intubation and later, hemodialysis due to metformin associated lactic acidosis and acute renal failure. Following 3 days of dialysis he was able to successfully wean from vent and pressors, making a complete recovery.

Conclusion:

We present a patient with EDKA likely resulting from dehydration induced AKI compounded by SGLT2i induced diuresis. As he developed his kidney injury, metformin was able to build up to toxic levels inducing lactic acidosis. Treatment in this patient was based on the underlying physiology providing glucose to allow resolution of ketosis. Treatment is not well studied, but given the origin of the pathology should resemble a standard DKA protocol with glucose repletion. SGLT2i and metformin combinations have shown an increased risk of metabolic acidosis¹ and lactic acidosis^2. This case highlights a potential risk of the combination in the setting of renal insufficiency and tenuous fluid states.

References:

(1) Donnan, Katherine, and Lakshman Segar. “SGLT2 Inhibitors and Metformin: Dual Antihyperglycemic Therapy and the Risk of Metabolic Acidosis in Type 2 Diabetes.” European Journal of Pharmacology, U.S. National Library of Medicine, 5 Mar. 2019.

(2) Schwetz V, Eisner F, Schilcher G, et al. Combined metformin-associated lactic acidosis and euglycemic ketoacidosis. Wien Klin Wochenschr. 2017;129(17-18):646–649. doi:10.1007/s00508-017-1251-6

Engineering Chirally Blind Protein Pseudocapsids into Antibacterial Persisters

Antimicrobial resistance stimulates the search for antimicrobial forms that may be less subject to acquired resistance. Here we report a conceptual design of protein pseudocapsids exhibiting a broad spectrum of antimicrobial activities. Unlike conventional antibiotics, these agents are effective against phenotypic bacterial variants, while clearing "superbugs" in vivo without toxicity. The design adopts an icosahedral architecture that is polymorphic in size, but not in shape, and that is available in both l and d epimeric forms. Using a combination of nanoscale and single-cell imaging we demonstrate that such pseudocapsids inflict rapid and irreparable damage to bacterial cells. In phospholipid membranes they rapidly convert into nanopores, which remain confined to the binding positions of individual pseudocapsids. This mechanism ensures precisely delivered influxes of high antimicrobial doses, rendering the design a versatile platform for engineering structurally diverse and functionally persistent antimicrobial agents.

Digital refocusing and extended depth of field reconstruction in Fourier ptychographic microscopy

Fourier ptychography microscopy (FPM) is a recently developed microscopic imaging method that allows the recovery of a high-resolution complex image by combining a sequence of bright and darkfield images acquired under inclined illumination. The capacity of FPM for high resolution imaging at low magnification makes it particularly attractive for applications in digital pathology which require imaging of large specimens such as tissue sections and blood films. To date most applications of FPM have been limited to imaging thin samples, simplifying both image reconstruction and analysis. In this work we show that, for samples of intermediate thickness (defined here as less than the depth of field of a raw captured image), numerical propagation of the reconstructed complex field allows effective digital refocusing of FPM images. The results are validated by comparison against images obtained with an equivalent high numerical aperture objective lens. We find that post reconstruction refocusing (PRR) yields images comparable in quality to adding a defocus term to the pupil function within the reconstruction algorithm, while reducing computing time by several orders of magnitude. We apply PRR to visualize FPM images of Giemsa-stained peripheral blood films and present a novel image processing pipeline to construct an effective extended depth of field image which optimally displays the 3D sample structure in a 2D image. We also show how digital refocusing allows effective correction of the chromatic focus shifts inherent to the low magnification objective lenses used in FPM setups, improving the overall quality of color FPM images.

Use of an automated knot fastener shortens operative times in minimally invasive mitral valve repair

INTRODUCTION

Longer durations of cardiopulmonary bypass and aortic cross clamp are associated with increased morbidity and mortality. Little is known about the effect of automated knot fasteners (Cor-Knot®) in minimally invasive mitral valve repair on operative times and outcomes. The aim of this study was to evaluate whether these devices shortened cardiopulmonary bypass and aortic cross clamp times and whether this impacted on postoperative outcomes.

MATERIALS AND METHODS

All patients undergoing isolated minimally invasive mitral valve repair by a single surgeon between March 2011 and March 2016 were included (n = 108). Two cohorts were created based on the use (n = 52) or non-use (n = 56) of an automated knot fastener. Data concerning intraoperative variables and postoperative outcomes were collected and compared.

RESULTS

Preoperative demographics were well matched between groups with no significant difference in logistic Euroscore (manual vs automated: median 3.1, interquartile range, IQR, 2.1-5.5, vs 5.4, IQR 2.2-8.3; P = 0.07, respectively). Comparing manually tied knots to an automated fastener, cardiopulmonary bypass and aortic cross clamp times were significantly shorter in the automated group (cardiopulmonary bypass: median 200 minutes, IQR 180-227, vs 165 minutes (IQR 145-189 minutes), P < 0.001; aortic cross clamp 134 minutes (IQR 121-150 minutes) vs 111 minutes (IQR 91-137 minutes), P < 0.001, respectively). There was no mortality and no strokes, nor were there any differences in postoperative outcomes including reoperation for bleeding, renal failure, intensive care or hospital stay.

CONCLUSIONS

The use of an automated knot fastener significantly reduces cardiopulmonary bypass and aortic cross clamp times in minimally invasive mitral valve repair but this does not translate into an improved clinical outcome.

Long term at-home treatment with transcranial direct current stimulation (tDCS) improves symptoms of cerebellar ataxia: a case report

BACKGROUND

Progressive cerebellar ataxia is a neurodegenerative disorder without effective treatment options that seriously hinders quality of life. Previously, transcranial direct current stimulation (tDCS) has been demonstrated to benefit cerebellar functions (including improved motor control, learning and emotional processing) in healthy individuals and patients with neurological disorders. While tDCS is an emerging therapy, multiple daily sessions are needed for optimal clinical benefit. This case study tests the symptomatic benefit of remotely supervised tDCS (RS-tDCS) for a patient with cerebellar ataxia.

METHODS

We report a case of a 71-year-old female patient with progressive cerebellar ataxia, who presented with unsteady gait and balance impairment, treated with tDCS. tDCS was administered using our RS-tDCS protocol and was completed daily in the patient's home (Monday - Friday) with the help of a trained study technician. tDCS was paired with 20 min of simultaneous cognitive training, followed by 20 min of physical exercises directed by a physical therapist. Stimulation consisted of 20 min of 2.5 mA direct current targeting the cerebellum via an anodal electrode and a cathodal electrode placed over the right shoulder. The patient completed baseline and treatment end visits with neurological, cognitive, and motor (Lafayette Grooved Pegboard Test, 25 ft walk test and Timed Up and Go Test) assessments.

RESULTS

The patient successfully completed sixty tDCS sessions, 59 of which were administered remotely at the patient's home with the use of real time supervision as enabled by video conferencing. Mild improvement was observed in the patient's gait with a 7% improvement in walking speed, which she completed without a walking-aid at treatment end, which was in stark contrast to her baseline assessment. Improvements were also achieved in manual dexterity, with an increase in pegboard scores bilaterally compared to baseline.

CONCLUSIONS

Results from this case report suggest that consecutively administered tDCS treatments paired with cognitive and physical exercise hold promise for improving balance, gait, and manual dexterity in patients with progressive ataxia. Remotely supervised tDCS provides home access to enable the administration over an extended period. Further controlled study in a large group of those with cerebellar ataxia is needed to replicate these findings.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT03049969 . Registered 10 February 2017- Retrospectively registered.

Generalizing remotely supervised transcranial direct current stimulation (tDCS): feasibility and benefit in Parkinson's disease

Background

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique that has been shown to improve common symptoms of neurological disorders like depressed mood, fatigue, motor deficits and cognitive dysfunction. tDCS requires daily treatment sessions in order to be effective. We developed a remotely supervised tDCS (RS-tDCS) protocol for participants with multiple sclerosis (MS) to increase accessibility of tDCS, reducing clinician, patient, and caregiver burden. The goal of this protocol is to facilitate home use for larger trials with extended treatment periods. In this study we determine the generalizability of RS-tDCS paired with cognitive training (CT) by testing its feasibility in participants with Parkinson’s disease (PD).

Methods

Following the methods in our MS protocol development, we enrolled sixteen participants (n = 12 male, n = 4 female; mean age 66 years) with PD to complete ten open-label sessions of RS-tDCS paired with CT (2.0 mA × 20 min) at home under the remote supervision of a trained study technician. Tolerability data were collected before, during, and after each individual session. Baseline and follow-up measures included symptom inventories (fatigue and sleep) and cognitive assessments.

Results

RS-tDCS was feasible and tolerable for patients with PD, with at-home access leading to high protocol compliance. Side effects were mostly limited to mild sensations of transient itching and burning under the electrode sites. Similar to prior finding sin MS, we found preliminary efficacy for improvement of fatigue and cognitive processing speed in PD.

Conclusions

RS-tDCS paired with CT is feasible for participants with PD to receive at home treatment. Signals of benefit for reduced fatigue and improved cognitive processing speed are consistent across the PD and MS samples. RS-tDCS can be generalized to provide tDCS to a range of patients with neurologic disorders for at-home rehabilitation.

Trial registration

ClinicalTrials.gov Identifier: NCT02746705. Registered April 21st 2016.

Microscope calibration using laser written fluorescence

There is currently no widely adopted standard for the optical characterization of fluorescence microscopes. We used laser written fluorescence to generate two- and three-dimensional patterns to deliver a quick and quantitative measure of imaging performance. We report on the use of two laser written patterns to measure the lateral resolution, illumination uniformity, lens distortion and color plane alignment using confocal and structured illumination fluorescence microscopes.

High affinity single-chain variable fragments are specific and versatile targeting motifs for extracellular vesicles

Exosomes are extracellular vesicles that mediate cell-to-cell communication by transferring biological cargo, such as DNA, RNA and proteins. Through genetic engineering of exosome-producing cells or manipulation of purified exosomes, it is possible to load exosomes with therapeutic molecules and target them to specific cells via the display of targeting moieties on their surface. This provides an opportunity to exploit a naturally-occurring biological process for therapeutic purposes. In this study, we explored the potential of single chain variable fragments (scFv) as targeting domains to achieve delivery of exosomes to cells expressing a cognate antigen. We generated exosomes targeting the Her2 receptor and, by varying the affinity of the scFvs and the Her2 expression level on recipient cells, we determined that both a high-affinity anti-Her2-scFv (K_D≤ 1 nM) and cells expressing a high level (≥10⁶ copies per cell) of Her2 were optimally required to enable selective uptake. We also demonstrate that targeting exosomes to cells via a specific cell surface receptor can alter their intracellular trafficking route, providing opportunities to influence the efficiency of delivery and fate of intracellular cargo. These experiments provide solid data to support the wider application of exosomes displaying antibody fragments as vehicles for the targeted delivery of therapeutic molecules.

Use of Dietary Management in Irritable Bowel Syndrome: Results of a Survey of Over 1500 United States Gastroenterologists

Background/Aims

Dietary therapy is increasingly used to manage gastrointestinal (GI) symptoms in patients with irritable bowel syndrome (IBS). We aim to gauge United States gastroenterologists’ perceptions of dietary therapies for IBS.

Methods

We distributed a 22-question survey to members of the American College of Gastroenterology. The survey was developed by gastroenterologists and survey methodologists. We collected information pertaining to demographics, providers’ interpretation of their patients’ views on dietary therapy, and gastroenterologists’ perceptions on dietary therapy, and nutritional counseling in IBS.

Results

One thousand five hundred and sixty-two (14%) surveys were collected. Nearly 60% of participants reported that patients commonly associate food with GI symptoms. IBS patients most commonly use a trial and error approach followed by a lactose-free and gluten-free diet, and rarely use a low fermentable oligosaccharides, disaccharides, monosaccharides, and polyols (FODMAP) diet on their own. Over half of providers recommend diet therapy to > 75% of IBS patients and most commonly recommend a low FODMAP diet. Only 21% of gastroenterologists commonly refer IBS patients to registered dietitians, and only 30% use GI dietitians. Female providers were more likely than males to recommend dietary changes as the primary mode of therapy (OR, 1.43 [1.09–1.88]; P = 0.009).

Conclusions

Our national survey identified enthusiasm for diet treatment of IBS. While patients infrequently tried a low FODMAP diet on their own, GI providers commonly recommended this diet. Only a minority of GI providers refer their IBS patients to a registered dietitian for nutrition counseling and few refer patients to dietitians with specialized GI training. Female providers were more enthusiastic about diet therapies than males.

Group-based patient education delivered by nurses to meet a clinical standard for glaucoma information provision: the G-TRAIN feasibility study

Background

Globally, glaucoma is the leading cause of irreversible blindness. However, many patients with glaucoma do not understand their disease which reportedly impacts on their ability to manage their condition successfully. The aim of this feasibility study was to undertake research to inform a future randomised controlled trial of the effectiveness of group-based education for patients to improve adherence to glaucoma eyedrops.

Methods

Key objectives were to understand current provision of information during routine nurse-led glaucoma consultations, to investigate if it is possible to deliver patient information in line with a clinical standard by training nurses to deliver group-based education in multiple hospital sites and to explore the acceptability of group-based education to nurses and patients compared with usual information provision in consultations. This study employed quantitative and qualitative research methods situated in a sequential design across three hospitals in England and Wales. Current provision of information given to 112 patients with glaucoma across the three hospitals was observed and compared to that recommended in a clinical standard. Then, six nurses were trained to deliver group-based education. Following which, the level of information was assessed again in line with the clinical standard as the group-based education programme was delivered in the three hospitals to 16 patients in total. All nurses and six patients were interviewed to explore experiences of the group-based education sessions.

Results

The main area of information provided during routine nurse-led consultations concerned the management of glaucoma and that least covered was about prognosis of the disease and information about support services. Nurses were trained to implement group-based education for patients. Information was provided more often by the nurses about all the items of the clinical standard when delivering group based education. However, patients’ motivation to attend were negatively impacted mainly by delays in delivering the education for the third phase and because the majority were established patients. Nurses and patients who participated found it useful and comprehensive.

Conclusion

This feasibility study demonstrates that the proposed intervention for the randomised controlled trial, the group-based education, goes beyond current information provision, is in line with that articulated by a clinical standard and is implementable across several sites. This bodes well for a future randomised trial, but the following needs to be taken into account to ensure success: independent implementation of the research, training and delivery at each site, timely provision of the patient education, inclusion of new patients, and consistently delivered nurse training.

Trial registration

International Standard Randomised Controlled Trial number, ISRCTN91188805

Three-dimensional behavioural phenotyping of freely moving C. elegans using quantitative light field microscopy

Behavioural phenotyping of model organisms is widely used to investigate fundamental aspects of organism biology, from the functioning of the nervous system to the effects of genetic mutations, as well as for screening new drug compounds. However, our capacity to observe and quantify the full range and complexity of behavioural responses is limited by the inability of conventional microscopy techniques to capture volumetric image information at sufficient speed. In this article we describe how combining light field microscopy with computational depth estimation provides a new method for fast, quantitative assessment of 3D posture and movement of the model organism Caenorhabditis elegans (C. elegans). We apply this technique to compare the behaviour of cuticle collagen mutants, finding significant differences in 3D posture and locomotion. We demonstrate the ability of quantitative light field microscopy to provide new fundamental insights into C. elegans locomotion by analysing the 3D postural modes of a freely swimming worm. Finally, we consider relative merits of the method and its broader application for phenotypic imaging of other organisms and for other volumetric bioimaging applications.