Time Is a Critical Factor When Evaluating Oligonucleotide Therapeutics in Human Ether-a-Go-Go-Related Gene Assays

In accord with International Conference on Harmonization S7B guidelines, an in vitro human ether-a-go-go-related gene (hERG) assay is one component of an integrated risk assessment for delayed ventricular repolarization. Function of hERG could be affected by direct (acute) mechanisms, or by indirect (chronic) mechanisms. Some approved oligonucleotide therapeutics had submitted hERG data to regulatory agents, which were all collected with the same protocol used for small-molecule testing (incubation time <20 min; acute), however, oligonucleotides have unique mechanisms and time courses of action (indirect). To reframe the hERG testing strategy for silencing RNA (siRNA), an investigation was performed to assess the time course for siRNA-mediated inhibition of hERG function and gene expression. Commercially available siRNAs of hERG were evaluated in a stable hERG-expressed cell line by whole-cell voltage clamp using automated electrophysiology and polymerase chain reaction. In the acute hERG study, no effects were observed after treatment with 100 nM siRNA for 20 min. The chronic effects of 100 nM siRNAs on hERG function were evaluated and recorded over 8-48 h following transfection. At 8 h there was no significant effect, whereas 77% reduction was observed at 48 h. Measurement of hERG mRNA levels demonstrated a 79% and 93% decrease of hERG mRNA at 8 and 48 h, respectively, consistent with inhibition of hERG transcription. The results indicate that an anti-hERG siRNA requires a long exposure time (48 h) in the hERG assay to produce a maximal reduction in hERG current; short exposures (20 min-8 h) had no effect. These findings imply that off-target profiling of novel oligonucleotides could benefit from using hERG protocol with long incubation times to de-risk potential off-target (indirect) effects on the hERG channel. This hERG assay modification may be important to consider if the findings are used to support an integrated nonclinical-clinical risk assessment for QTc (the duration of the QT interval adjusted for heart rate) prolongation.

An Audit on Oncological Safety with Magseed Localised Breast Conserving Surgery

Wire-localised wide local excision (W-WLE) has been standard of care for impalpable breast lesions. Logistics and risks of wire localisation can be challenging. Magseed-localised wide local excision (M-WLE) is an alternative to W-WLE. We compare safety parameters and length of hospital stay (LOS) in patients undergoing M-WLE to W-WLE. All M-WLEs performed at single institution over an 8-month period were included and compared to historic matched cohort of W-WLEs who would have been suitable for Magseed localisation. Data including patient demographics, successful placements, re-excision rates, tumour size, and length of stay (LOS) was analysed. Two hundred thirty-eight patients were included in the study. Cancers were safely excised in all cases. A significant difference in re-excisions rates favouring M-WLE group was seen (2.9% vs 10.4%). Median waiting time to surgery was significantly shorter in M-WLE group (4 h 15 min vs 7 h 3 min). No significant difference in median LOS between the two groups was seen. M-WLE has been shown to be oncologically safe and non-inferior to W-WLE with significantly lower re-excision rate. Reduced pre-operative waiting time in the M-WLE group will have a positive effect on patient journey. Further research should focus on potential impact on day-bed utilisation and theatre efficiency.

Development of ASIC1a ligand-gated ion channel drug screening assays across multiple automated patch clamp platforms

Human acid-sensing ion channels (ASIC) are ligand-gated ionotropic receptors expressed widely in peripheral tissues as well as sensory and central neurons and implicated in detection of inflammation, tissue injury, and hypoxia-induced acidosis. This makes ASIC channels promising targets for drug discovery in oncology, pain and ischemia, and several modulators have progressed into clinical trials. We describe the use of hASIC1a as a case study for the development and validation of low, medium and high throughput automated patch clamp (APC) assays suitable for the screening and mechanistic profiling of new ligands for this important class of ligand-gated ion channel. Initial efforts to expand on previous manual patch work describing an endogenous hASIC1a response in HEK cells were thwarted by low current expression and unusual pharmacology, so subsequent work utilized stable hASIC1a CHO cell lines. Ligand-gated application protocols and screening assays on the Patchliner, QPatch 48, and SyncroPatch 384 were optimized and validated based on pH activation and nM-μM potency of reference antagonists (e.g., Amiloride, Benzamil, Memantine, Mambalgin-3, A-317567, PcTx1). By optimizing single and stacked pipette tip applications available on each APC platform, stable pH-evoked currents during multiple ligand applications enabled cumulative EC₅₀ and IC₅₀ determinations with minimized receptor desensitization. Finally, we successfully demonstrated for the first time on an APC platform the ability to use current clamp to implement the historical technique of input resistance tracking to measure ligand-gated changes in membrane conductance on the Patchliner platform.

Abstract PS1-34: Oncological safety and patient journey with magseed™ localised breast conserving surgery

Introduction: Wire localised wide local excision (W-WLE) has been the standard of care for impalpable breast lesions and requires insertion of the wire on the same day as the surgery. Logistics of same day localisation can lead to a chaotic morning for the patients with long uncomfortable waiting times prior to their surgery. Transporting patients across the hospital and at times between different sites can add to poor patient experience and inefficient theatre utilisation. Magseed localised wide local excision (M-WLE) is an alternative to W-WLE. Magseed is a 5mm non-radioactive paramagnetic seed inserted radiologically and in the UK it is licensed for insertion up to 30 days in advance. M-WLE was started for routine use in our Unit in July 2019. We compare the safety parameters and length of hospital stay (LOS) in patients undergoing M-WLE to W-WLE. Methods: All M-WLEs performed at a single institution over an 8 month period (Jul 19 - Feb 20) were included. These were compared to a historic matched cohort of W-WLEs performed over 8 months (Jan 18 - Aug 18) which would have been suitable for Magseed localisation. The suitability for Magseed localisation was decided by a breast radiologist based on local objective criteria. Intra-operative cavity shaves were performed based on specimen X-ray and re-excisions were performed where there was tumour at or &lt; 1 mm from inked margin. Exclusion criteria for Magseed localisations included - i. multiple lesions requiring 2 or more wires and ii. Depth of lesion from skin (&gt;3cm on ultrasound or &gt;7cm deep in central breast on mammogram). Data including patient demographics, type of localisation, successful placements, pathology, re-excision rates, tumour size, and length of stay (LOS) was collected and analysed. Results: Over the 16 months, 319 patients underwent localised WLEs. 238 patients were included in the study and 81 excluded. Patient demographics and tumour characteristics are detailed in Table 1. There is no significant difference in the intra-operative cavity shaves between the two groups. A significant difference in the re-excisions rates favouring the M-WLE group despite no significant difference in the mean tumour to specimen ratio was seen. (Table 2) The median waiting time to surgery from the time of admission was observed to be significantly shorter in the M-WLE group (4h15mins vs 7h03mins, p&lt;0.01). There was no significant difference in the median LOS between the two groups (M-WLE 13h44mins, W-WLE 13h56mins, p=0.36). The overall day surgery rates were comparable in the two groups (M-WLE 75.2%, W-WLE 75.1%, p=0.99). Conclusion: In the present series, M-WLE has been shown to be oncologically safe and non-inferior to W-WLE with a significantly lower re-excision rate. In addition to this, the reduced pre-operative waiting time on the day of surgery in the M-WLE group will have a positive effect on the patient journey. Further research should focus on the potential impact on day-bed utilisation and theatre efficiency.

Table 1: Patient demographics and tumour characteristicsMagseed™Wirep valuen105133Median age (years)64 (34-87)60 (28-82)0.05Median BMI28.2 (17-54.4)28.3 (18.8-43.1)0.62PathologyInvasive+/-DCIS851100.31DCIS1715Others38Mean tumour diameter (mm)Invasive+/-DCIS15.19 (3-55)15.52 (1-15)0.82DCIS9.41 (3-45)17.12 (3-55)0.13

Table 2: Tumour to specimen ratio, further intra-operative cavity shaves and re-excision ratesMagseed™Wirep valuen102125Mean Tumour/Specimen RatioInvasive+/-DCIS8.8%18.1%0.20DCIS18.4%24.8%0.75Further intra-operative cavity shavesTotal48 (47.0%)68 (54.4%)0.27Invasive+/-DCIS28/64 (43.7%)56/102 (54.9%)0.16DCIS7/15 (46.6%)8/15 (53.3%)0.71Oncoplastic procedures: Invasive+/-DCIS12/21 (57.1%)4/7 (57.1%)1Oncoplastic procedures: DCIS1/2 (50%)0/1 (0%)NARe-excisions of marginsTotal3 (2.9%)13 (10.4%)0.03Invasive+/-DCIS3/64 (4.6%)8/102 (7.8%)0.4DCIS0/15 (0%)5/15 (33.3%)NAOncoplastic procedures: Invasive+/-DCIS0/21 (0%)0/7 (0%)NAOncoplastic procedures: DCIS0/2 (0%)0/1 (0%)NA

Citation Format: Kirti Katherine Kabeer, Manoj S Gowda, Zatinahhayu MohdIsa, Megan Thomas, Vallipuram Gopalan, Sadaf Jafferbhoy, Soni Soumian, Sankaran Narayanan, Robert Kirby, Sekhar Marla. Oncological safety and patient journey with magseed™ localised breast conserving surgery [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS1-34.

Simulation of airfoil surface pressure due to incident turbulence using realizations of uncorrelated wall plane waves

A numerical technique is proposed for synthesizing realizations of airfoil surface pressure induced by incoming turbulence. In this approach, realization of the surface pressure field is expressed as a set of uncorrelated wall plane waves. The amplitude of these plane waves is determined from the power spectrum density function of the incoming upwash velocity fluctuation and the airfoil aeroacoustic transfer function. The auto-spectrum of the surface pressure is obtained from an ensemble average of different realizations. The numerical technique is computationally efficient as it rapidly converges using a relatively small number of realizations. The surface pressures for different airfoils excited by incoming turbulence are numerically predicted, and the results are compared with experimental data in the literature. Further, the unsteady force exerted on an airfoil due to the airfoil-turbulence interaction is also computed, and it is shown to be in very good agreement with analytical results.

Effect of selective IK,ACh inhibition by XAF-1407 in an equine model of tachypacing-induced persistent atrial fibrillation

BACKGROUND AND PURPOSE

Inhibition of the G-protein gated ACh-activated inward rectifier potassium current, I_K,ACh may be an effective atrial selective treatment strategy for atrial fibrillation (AF). Therefore, the anti-arrhythmic and electrophysiological properties of a novel putatively potent and highly specific I_K,ACh inhibitor, XAF-1407 (3-methyl-1-[5-phenyl-4-[4-(2-pyrrolidin-1-ylethoxymethyl)-1-piperidyl]thieno[2,3-d]pyrimidin-6-yl]azetidin-3-ol), were characterised for the first time in vitro and investigated in horses with persistent AF.

EXPERIMENTAL APPROACH

The pharmacological ion channel profile of XAF-1407 was investigated using cell lines expressing relevant ion channels. In addition, eleven horses were implanted with implantable cardioverter defibrillators enabling atrial tachypacing into self-sustained AF. The electrophysiological effects of XAF-1407 were investigated after serial cardioversions over a period of 1 month. Cardioversion success, drug-induced changes of atrial tissue refractoriness, and ventricular electrophysiology were assessed at baseline (day 0) and days 3, 5, 11, 17, and 29 after AF induction.

KEY RESULTS

XAF-1407 potently and selectively inhibited K_ir 3.1/3.4 and K_ir 3.4/3.4, underlying the I_K,ACh current. XAF-1407 treatment in horses prolonged atrial effective refractory period as well as decreased atrial fibrillatory rate significantly (~20%) and successfully cardioverted AF, although with a decreasing efficacy over time. XAF-1407 shortened atrioventricular-nodal refractoriness, without effect on QRS duration. QTc prolongation (4%) within 15 min of drug infusion was observed, however, without any evidence of ventricular arrhythmia.

CONCLUSION AND IMPLICATIONS

XAF-1407 efficiently cardioverted sustained tachypacing-induced AF of short duration in horses without notable side effects. This supports I_K,ACh inhibition as a potentially safe treatment of paroxysmal AF in horses, suggesting potential clinical value for other species including humans.

Patient-reported Upper Limb Function After Sentinel Lymph Node Biopsy for Breast Cancer: A Prospective Observational Study

INTRODUCTION

Sentinel lymph node biopsy (SLNB) is the standard procedure for axillary staging in breast cancer. There is a lack of consistency in studies reporting on upper limb morbidity after SLNB. We present a prospective study evaluating upper limb function after SLNB using the validated quickDASH questionnaire.

MATERIALS AND METHODS

Consecutive patients who underwent wide local excision and SLNB were included in the study. Arm function was assessed using the quickDASH questionnaire at 3 time points - prior to surgery and 2 weeks and 3 months after SLNB. The scores obtained were labeled as A, B, and C respectively. The mean and median scores were compared using the paired t test and Wilcoxon signed rank test.

RESULTS

Ninety-nine patients met all inclusion criteria and were included in the final analysis. The mean A, B, and C scores were 8.46, 16.05, and 13.36. The median A, B, and C scores were 2.27, 7.5, and 4.54. There was a statistically significant difference between mean and median A and B scores, B and C scores, and A and C scores. A similar trend was observed in patients with better preoperative upper limb function. Patients with a higher body mass index had significantly worse B and C scores.

CONCLUSION

There is a significant deterioration in upper limb function following SLNB. This improves at 3 months but does not reach baseline levels. Larger studies with long-term follow-up are required to establish the extent of upper limb functional morbidity and natural course of functional recovery after SLNB.

A systematic strategy for estimating hERG block potency and its implications in a new cardiac safety paradigm

Introduction

hERG block potency is widely used to calculate a drug's safety margin against its torsadogenic potential. Previous studies are confounded by use of different patch clamp electrophysiology protocols and a lack of statistical quantification of experimental variability. Since the new cardiac safety paradigm being discussed by the International Council for Harmonisation promotes a tighter integration of nonclinical and clinical data for torsadogenic risk assessment, a more systematic approach to estimate the hERG block potency and safety margin is needed.

Methods

A cross-industry study was performed to collect hERG data on 28 drugs with known torsadogenic risk using a standardized experimental protocol. A Bayesian hierarchical modeling (BHM) approach was used to assess the hERG block potency of these drugs by quantifying both the inter-site and intra-site variability. A modeling and simulation study was also done to evaluate protocol-dependent changes in hERG potency estimates.

Results

A systematic approach to estimate hERG block potency is established. The impact of choosing a safety margin threshold on torsadogenic risk evaluation is explored based on the posterior distributions of hERG potency estimated by this method. The modeling and simulation results suggest any potency estimate is specific to the protocol used.

Discussion

This methodology can estimate hERG block potency specific to a given voltage protocol. The relationship between safety margin thresholds and torsadogenic risk predictivity suggests the threshold should be tailored to each specific context of use, and safety margin evaluation may need to be integrated with other information to form a more comprehensive risk assessment.

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hERG potency/safety margin is a widely used nonclinical cardiac safety strategy.

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A new regulatory paradigm promotes the integration of nonclinical and clinical data.

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Lack of uncertainty quantification hindered using hERG potency in the new paradigm.

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A systematic method was established to address this limitation.

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Analysis supports using different safety margin thresholds in different context.

A comparative analysis of axillary nodal burden in ultrasound/biopsy positive axilla vs ultrasound negative sentinel lymph node biopsy positive axilla

BACKGROUND

Axillary Ultrasound (AUS) is now performed as a protocol in every newly diagnosed breast cancer in most European countries. It is an inexpensive and sensitive tool in hands of a trained operator. All AUS negative patients undergo Sentinel Lymph Node Biopsy (SLNB), while AUS positive patients bypass SLNB and undergo axillary nodal clearance (ANC) as a standard protocol. We wish to analyse these two groups to see if ANC can be foregone in these patients.

AIMS AND OBJECTIVES

To compare and analyse the axillary disease burden in early breast cancer patients, with positive axilla, detected by AUS+ Biopsy versus those patients with normal axillary ultrasound or negative axillary biopsy that underwent ANC due to positive SLNB.

MATERIAL AND METHODS

A retrospective review of all patients who underwent axillary lymph node clearance following histologically confirmed positive ultrasound (US) axilla (year 2009-2014) was performed and was compared with data collected for patients with USG negative but SLNB (OSNA- One Step Nucleic Acid Amplification) positive axilla.

RESULTS

Axillary clearances performed for positive US axilla yielded significantly more positive lymph nodes than SLNB/OSNA positive axilla (p = 0.00496). These patients also had larger primary tumours (median 33 mm versus 21 mm, p = 0.01242) of a higher grade. Almost half of the patients in AUS positive group (49%) had high axillary nodal burden (>4 LNs). This is in great contrast with AUS negative, SLNB/OSNA positive group where 82.7% of patients had <4 positive nodes with more than half patients (51.7%) having no further positive nodes in their final histopathology specimen.

CONCLUSIONS

ANC should be a standard protocol in AUS positive patients as they invariably have high axillary disease burden while ANC can be omitted in case of select AUS negative and SLNB patients. However, further studies with more subjects may be require to substantiate the findings.

Oxidative Stress and Cardiovascular Risk in Type 1 Diabetes Mellitus: Insights From the DCCT/EDIC Study

Background

Hyperglycemia leading to increased oxidative stress is implicated in the increased risk for the development of macrovascular and microvascular complications in patients with type 1 diabetes mellitus.

Methods and Results

A random subcohort of 349 participants was selected from the DCCT / EDIC (Diabetes Control and Complications Trial/Epidemiology of Diabetes Interventions and Complications) cohort. This included 320 controls and 29 cardiovascular disease cases that were augmented with 98 additional known cases to yield a case cohort of 447 participants (320 controls, 127 cases). Biosamples from DCCT baseline, year 1, and closeout of DCCT , and 1 to 2 years post‐ DCCT ( EDIC years 1 and 2) were measured for markers of oxidative stress, including plasma myeloperoxidase, paraoxonase activity, urinary F 2α isoprostanes, and its metabolite, 2,3 dinor‐8 iso prostaglandin F 2α . Following adjustment for glycated hemoblobin and weighting the observations inversely proportional to the sampling selection probabilities, higher paraoxonase activity, reflective of antioxidant activity, and 2,3 dinor‐8 iso prostaglandin F 2α , an oxidative marker, were significantly associated with lower risk of cardiovascular disease (−4.5% risk for 10% higher paraoxonase, P <0.003; −5.3% risk for 10% higher 2,3 dinor‐8 iso prostaglandin F 2α , P =0.0092). In contrast, the oxidative markers myeloperoxidase and F 2α isoprostanes were not significantly associated with cardiovascular disease after adjustment for glycated hemoblobin. There were no significant differences between DCCT intensive and conventional treatment groups in the change in all biomarkers across time segments.

Conclusions

Heightened antioxidant activity (rather than diminished oxidative stress markers) is associated with lower cardiovascular disease risk in type 1 diabetes mellitus, but these biomarkers did not change over time with intensification of glycemic control.

Clinical Trial Registration

URL : https://www.clinicaltrials.gov . Unique identifiers: NCT 00360815 and NCT 00360893.

Note. Reaction of Bacteria Associated with Fish Spoilage to Chemical and Physical Stress

A cocktail made up of six bacteria isolated from fish was subjected to various heats (30 °C and 60 °C, 20 s) and chemical preservative stresses, alone and in combination. The chemical preservatives tested were potassium sorbate (PS, 1%), trisodium phosphate (TSP, 10%) and tetrasodium pyrophosphate (TSPP, 3%). Heating the bacteria at 60 °C for 20 s resulted in an average reduction of 2.0 log cfu/mL in the total number. The results showed amarked synergistic effect of heat treatment prior to chemical additives, especially for TSPP and sorbate; no significant effect was evident when chemicals were applied alone. The effect was increased by the application of chemical preservatives, before heating, in the decreasing order TSP, TSPP and sorbate; reductions obtained were more than 5.0, 4.0 and 3.0 log cfu/mL, respectively. The synergistic effect observed was dependent on the type of chemical additives used and also on the order of the treatments. Bacteria identified as Shewanella putrefaciens and Pseudomonas putida were more resistant to heat treatment and Brochothrix thermosphacta and Lactobacillus plantarum were more resistant to TSP treatment. These bacteria in the cocktail showed high sensitivity to combined TSP/heat treatment; bacterial cells identified as Enterobacter spp. were the most resistant to this treatment.

Contemporary characteristics of blunt abdominal trauma in a regional series from the UK

INTRODUCTION Blunt abdominal trauma (BAT) is a common injury in recent trauma series. The characteristics of patients with BAT have changed following the reconfiguration of UK trauma services. The aim of this study was to build a new profile for BAT patients undergoing immediate or delayed laparotomy. METHODS All 5,401 consecutive adults presenting with major trauma between April 2012 and April 2014 in the 3 major trauma centres in the West Midlands were analysed to identify all patients with BAT. A total of 2,793 patients with a mechanism of injury or symptomatology consistent with BAT were identified (52%). Outcomes were analysed using local electronic clinical results systems and notes. RESULTS Of the 2,793 patients, 179 (6.4%) had a mesenteric or hollow viscus injury, 168 (6.0%) had a hepatobiliary injury, 149 (5.4%) had a splenic injury and 46 (1.6%) had a vascular injury. Overall, 103 patients (3.7%) underwent an early (<12 hours) laparotomy while 30 (1.1%) underwent a delayed (>12 hours) laparotomy. Twenty (66.7%) of those undergoing a delayed laparotomy had a hollow viscus injury. In total, 170 deaths occurred among the BAT patients (6.1%). In the early laparotomy group, 53 patients died (51.5%) whereas in the delayed laparotomy group, 6 patients died (20.0%). CONCLUSIONS This series has attempted to provide the characteristics of patients with BAT in a large contemporary UK cohort. BAT was found to be a common type of injury. Early and delayed laparotomy occurred in 3.7% and 1.1% of these patients respectively, mostly because of hollow viscus injury in both cases. Outcomes were comparable with those in the international literature from regions with mature trauma services.

Primary mesenteric gastrointestinal stromal tumour

Primary mesenteric gastrointestinal stromal tumours (GISTs) are rare tumours and can be included as a differential for an expanding intraabdominal mass. We present the case, in our institution, of a 72-year-old male who presented with non-specific symptoms and was diagnosed with a primary mesenteric GIST following resection. We report his follow-up and discuss the current theories as to the origins of these rare tumours and current treatment modalities.

Action of clathrodin and analogues on voltage-gated sodium channels

Clathrodin is a marine alkaloid and believed to be a modulator of voltage-gated sodium (Na(V)) channels. Since there is an urgent need for small molecule Na(V) channel ligands as novel therapeutics, clathrodin could represent an interesting lead compound. Therefore, clathrodin was reinvestigated for its potency and Na(V) channel subtype selectivity. Clathrodin and its synthetic analogues were subjected to screening on a broad range of Na(V) channel isoforms, both in voltage clamp and patch clamp conditions. Even though clathrodin was not found to exert any activity, some analogues were capable of modulating the Na(V) channels, hereby validating the pyrrole-2-aminoimidazole alkaloid structure as a core structure for future small molecule-based Na(V) channel modulators.

Primary gut aspergillosis in a patient with acute myeloid leukaemia: the importance of early suspicion and definitive treatment

Aspergillus infection is a known complication in immunocompromised patients, particularly in those with impaired neutrophil function. The pathophysiology of respiratory tract infection and disseminated disease are well understood, and guidelines exist for early detection and treatment. The gut has been speculated to be the potential portal of entry for Aspergillus, though previous case series outline that this is often discovered late and results in high morbidity and mortality. Early clinical suspicion, with definitive surgical intervention and antifungal treatment with voriconazole, can significantly increase the chances of survival. In this article, the authors discuss a case of primary gut aspergillosis with secondary dissemination in a patient with acute myeloid leukaemia who developed serious sequelae.

Breast cancer after prophylactic mastectomy for Lobular Carcinoma-In-Situ (LCIS) - an unusual case

Bilateral risk reducing mastectomy results in the greatest breast cancer risk reduction but is an irreversible intervention. Total mastectomy can never remove all breast tissue and there is always a small risk of breast cancer. Regular follow up and surveillance is beneficial. We present the case of a 47-year-old woman who presented with axillary lymph node metastatic breast cancer after risk reducing mastectomy in which only Lobular Carcinoma-in-Situ (LCIS) was present on histopathology.

Elective right hemicolectomy: a twenty-year retrospective analysis of a single general surgeon's practice

AIM

Changes in working practices implemented over the last decade particularly with respect to subspecialisation have changed the working practices of the traditional general surgeon. The majority of non-colorectal specialists who wish to continue abdominal surgery have been limited to pursue right sided colorectal pathology only. The aim of this study was to assess the outcomes of colorectal procedures performed by one non-colorectal specialist general surgeon who commenced consultant practice in 1991 and compare these outcomes against the outcomes recorded in the literature for low and high volume caseload surgeons.

METHODS

The patient records of 131 patients who underwent right hemicolectomy by a single surgeon between March 1991 and December 2010 were retrieved and retrospectively analysed. All patients underwent midline laparotomy with two-layer handsewn end-end or end-side ileocolonic anastomoses. Complications of interest were postoperative deaths and clinically relevant anastomotic leaks as well as clinically diagnosed medical complications.

RESULTS

The mean age of patients was 61.5 years (range 17-83). A total of 92 patients were operated upon for colorectal malignancy and 39 patients for crohn's disease. No anastomotic leaks occurred. There was only a single inpatient death secondary to acute myocardial infarction.

CONCLUSION

Our small study of a single surgeon's career long practice for elective right hemicolectomies demonstrates that high standards in terms of anastomotic leak rates and operative mortality can be achieved in clinical practice by the non-specialist General Surgeon. However, prospective data collection would be required to apply this to the broader non-colorectal specialist community.

Deactivating chemical agents using enzyme-coated nanofibers formed by electrospinning

The coaxial electrospinning technique was investigated as a novel method to create stabilized, enzyme-containing fibers that have the potential to provide enhanced protection from chemical agents. Electrospinning is a versatile technique for the fabrication of polymer fibers with large length (cm to km): diameter (nm to μm) aspect ratios. The large surface to volume ratios, along with the biofriendly nature of this technique, enables the fabrication of fiber mats with high enzyme concentrations, which amplify the catalytic activity per unit volume of membrane. Blended composite (single-source) fibers incorporate enzyme throughout the fiber, which may limit substrate accessibility to the enzyme. In contrast, core/sheath fibers can be produced by coaxial electrospinning with very high enzyme loading (>80%) in the sheath without noticeable loss of enzymatic activity. Several core-sheath combinations have been explored with the toxin-mitigating enzyme DFPase in order to achieve fibers with optimum properties. The concentration of fluoride released, normalized for the amount of protein incorporated into the sheath, was used as a measure of the enzyme activity versus time. The coaxial core/sheath combination of PEO and DFPase produced the highest activity (~7.3 mM/mg).

Distribution, transport and exchanges of fine sediment, with tidal power implications: Severn Estuary, UK

The Severn, a hypertidal, high turbidity estuary, has a bed largely stripped of unconsolidated sediment. Its inter-tidal zone is mainly mudflats, the universal erosional trend of which is now proven. These are a source for sub-tidal mud accumulations in Newport Deep, much of Bridgwater Bay, less so in Bristol Deep and Cardiff Roads. The main estuary turbidity maximum is dominated by its exceptional turbidity and the cycling of this on two tidal timescales. It is the means to exchange fines between sources and sinks. It shows discontinuities in three planes - lutoclines, suspended sediment fronts and slug flow. Much of the estuary is verging on or actually barren. It has been designated under EU legislation for its fine sediment-induced naturally-depauperate nature. This is invalid as it is complicated by large scale ecosystem collapse due to climate change. Building a Cardiff-Weston barrage would induce a large rise in faunal abundance and biodiversity.

Clinical presentation and initial management of black men and white men with prostate cancer in the United Kingdom: the PROCESS cohort study

Background:

In the United States, Black men have a higher risk of prostate cancer and worse survival than do White men, but it is unclear whether this is because of differences in diagnosis and management. We re-examined these differences in the United Kingdom, where health care is free and unlikely to vary by socioeconomic status.

Methods:

This study is a population-based retrospective cohort study of men diagnosed with prostate cancer with data on ethnicity, prognostic factors, and clinical care. A Delphi panel considered the appropriateness of investigations and treatments received.

Results:

At diagnosis, Black men had similar clinical stage and Gleason scores but higher age-adjusted prostate-specific antigen levels (geometric mean ratio 1.41, 95% confidence interval (95% CI): 1.15–1.73). Black men underwent more investigations and were more likely to undergo radical treatment, although this was largely explained by their younger age. Even after age adjustment, Black men were more likely to undergo a bone scan (odds ratio 1.37, 95% CI: 1.05–1.80). The Delphi analysis did not suggest differential management by ethnicity.

Conclusions:

This UK-based study comparing Black men with White men found no evidence of differences in disease characteristics at the time of prostate cancer diagnosis, nor of under-investigation or under-treatment in Black men.