Colon capsule endoscopy.

There are multiple indications for luminal imaging of the colon. From assessment of known disease, to diagnosing new pathology; intra-luminal visualisation is the mainstay of gastrointestinal diagnosis. Colonoscopy and radiological imaging are currently the most frequently deployed diagnostic methods. However, both have an associated risk profile, have significant resource pressures and are not universally tolerated. Colon capsule endoscopy (CCE) offers an adjunct to these diagnostic options. In this narrative review the utility of CCE is described. Its current uses, potential benefits and future developments are also discussed.

Engaging stakeholders in research to address water-energy-food (WEF) nexus challenges.

The water-energy-food (WEF) nexus has become a popular, and potentially powerful, frame through which to analyse interactions and interdependencies between these three systems. Though the case for transdisciplinary research in this space has been made, the extent of stakeholder engagement in research remains limited with stakeholders most commonly incorporated in research as end-users. Yet, stakeholders interact with nexus issues in a variety of ways, consequently there is much that collaboration might offer to develop nexus research and enhance its application. This paper outlines four aspects of nexus research and considers the value and potential challenges for transdisciplinary research in each. We focus on assessing and visualising nexus systems; understanding governance and capacity building; the importance of scale; and the implications of future change. The paper then proceeds to describe a novel mixed-method study that deeply integrates stakeholder knowledge with insights from multiple disciplines. We argue that mixed-method research designs-in this case orientated around a number of cases studies-are best suited to understanding and addressing real-world nexus challenges, with their inevitable complex, non-linear system characteristics. Moreover, integrating multiple forms of knowledge in the manner described in this paper enables research to assess the potential for, and processes of, scaling-up innovations in the nexus space, to contribute insights to policy and decision making.

Errors detected in pediatric oral liquid medication doses prepared in an automated workflow management system.

PURPOSE: The effectiveness of barcode-assisted medication preparation (BCMP) technology on detecting oral liquid dose preparation errors. METHODS: From June 1, 2013, through May 31, 2014, a total of 178,344 oral doses were processed at Children's Mercy, a 301-bed pediatric hospital, through an automated workflow management system. Doses containing errors detected by the system's barcode scanning system or classified as rejected by the pharmacist were further reviewed. Errors intercepted by the barcode-scanning system were classified as (1) expired product, (2) incorrect drug, (3) incorrect concentration, and (4) technological error. Pharmacist-rejected doses were categorized into 6 categories based on the root cause of the preparation error: (1) expired product, (2) incorrect concentration, (3) incorrect drug, (4) incorrect volume, (5) preparation error, and (6) other. RESULTS: Of the 178,344 doses examined, 3,812 (2.1%) errors were detected by either the barcode-assisted scanning system (1.8%, n = 3,291) or a pharmacist (0.3%, n = 521). The 3,291 errors prevented by the barcode-assisted system were classified most commonly as technological error and incorrect drug, followed by incorrect concentration and expired product. Errors detected by pharmacists were also analyzed. These 521 errors were most often classified as incorrect volume, preparation error, expired product, other, incorrect drug, and incorrect concentration. CONCLUSION: BCMP technology detected errors in 1.8% of pediatric oral liquid medication doses prepared in an automated workflow management system, with errors being most commonly attributed to technological problems or incorrect drugs. Pharmacists rejected an additional 0.3% of studied doses.

Preoperative fasting: current practice and areas for improvement.

Preoperative fasting aims to increase patient safety by reducing the risk of adverse events during general anaesthesia. However, prolonged fasting may be associated with dehydration, hypoglycaemia and electrolyte imbalance as well as patient discomfort. We aimed to examine compliance with the current best practice guidelines in a large surgical unit and to identify areas for improvement. Adult patients undergoing elective and emergency general, orthopaedic, gynaecology and vascular surgery procedures in the Royal Infirmary of Edinburgh were surveyed over a 3-month period commencing November 2011. A standardised questionnaire was used to collect information on the duration of preoperative fasting and the advice administered by medical and nursing staff. 292 patients were included. Median fast from solids was 13.5 h for elective patients (IQR 11.5-16) and 17.38 h for emergency patients (IQR 13.68-28.5 h). Similarly, the median fast from fluids was 9.36 h for elective patients (IQR 5.38-12.75 h) and 12.97 h for emergency patients (IQR 8.5-16.22 h). The instructions that elective patients received contributed to prolonged fasting times. The median fast for elective patients fully compliant with fasting advice would be 10 h for solids (IQR 8.75-12 h) and 6.25 h (IQR 3.83-9.25 h) for clear fluids. Elective patients fasted for longer than recommended confirming that clinical practice is slow to change. The use of universal fasting instructions and patient choice are factors that unnecessarily prolong preoperative fasting, which however appears to be multifactorial. Service improvement by abbreviation of the observed fasting periods will rely on targeted staff education and effective clinical communication by provision of written information for both elective and emergency surgical patients. The routine use of preoperative nutritional supplements may need to be re-examined when further evidence is available.

Polysialyltransferase: a new target in metastatic cancer.

Polysialic acid (polySia) is a carbohydrate polymer critical for neuronal cell migration and axon pathfinding in embryonic development. Besides brain regions requiring persistent neuronal plasticity, polySia is essentially absent from the adult body. However, polySia is aberrantly re-expressed on many tumours, where it decorates the surface of NCAM (neuronal cell adhesion molecule) and modulates cell adhesion, migration and invasion. PolySia-NCAM expression is strongly associated with poor clinical prognosis and correlates with aggressive and invasive disease in many cancers, including lung cancer, neuroblastoma and gliomas. The synthesis of polySia is mediated by two polysialyltransferases (polySTs), ST8SiaIV (PST) and particularly ST8SiaII (STX) in cancer cells. The demonstration that polyST knock-down negates events associated with tumour cell dissemination indicates that PST and STX are validated targets. Selective inhibition of polySTs therefore presents a therapeutic opportunity to inhibit tumour invasion and metastasis.

A modelling assessment of contaminant distributions in the Severn Estuary.

The regulatory requirements imposed by the Habitats Directive (EU 93/43/EEC) require the Environment Agency for England and Wales (EA) to review consented discharges and determine whether they are compliant with Environmental Quality Standards (EQS). Since the EQS are annual averages, model predictions, and sample comparisons, should be made on an annual average basis. Advection and dispersion of metal contaminants in the Severn Estuary were computed using a coupled 1-D and 2-D hydrodynamic-water quality model. The external inputs of dissolved copper, arsenic, mercury and chromium to the model were from 66 industrial discharges and sewage treatment works and 30 rivers. The annual average predicted concentrations were compared with the annual average dissolved metal concentrations from the 2004 and 2005 monitoring programme, and any discrepancy used to identify the role of additional processes, mainly involving the sediments. This ability to separate anthropogenic inputs from internal estuarine processes contributes to a better understanding of the functioning of the estuary and hence an improved management capability. The paper discusses the approach in designing scenarios and characterising uncertainty, when decision-making in the regulatory context.

The chromatography-free release, isolation and purification of recombinant peptide for fibril self-assembly.

One of the major expenses associated with recombinant peptide production is the use of chromatography in the isolation and purification stages of a bioprocess. Here we report a chromatography-free isolation and purification process for recombinant peptide expressed in Escherichia coli (E. coli). Initial peptide release is by homogenization and then by enzymatic cleavage of the peptide-containing fusion protein, directly in the E. coli homogenate. Release is followed by selective solvent precipitation (SSP) to isolate and purify the peptide away from larger cell contaminants. Specifically, we expressed in E. coli the self-assembling beta-sheet forming peptide P(11)-2 in fusion to thioredoxin. Homogenate was heat treated (55 degrees C, 15 min) and then incubated with tobacco etch virus protease (TEVp) to release P(11)-2 having a native N-terminus. SSP with ethanol at room temperature then removed contaminating proteins in an integrated isolation-purification step; it proved necessary to add 250 mM NaCl to homogenate to prevent P(11)-2 from partitioning to the precipitate. This process structure gave recombinant P(11)-2 peptide at 97% polypeptide purity and 40% overall yield, without a single chromatography step. Following buffer-exchange of the 97% pure product by bind-elute chromatography into defined chemical conditions, the resulting peptide was shown to be functionally active and able to form self-assembled fibrils. To the best of our knowledge, this manuscript reports the first published process for chromatography-free recombinant peptide release, isolation and purification. The process proved able to deliver functional recombinant peptide at high purity and potentially low cost, opening cost-sensitive materials applications for peptide-based materials.

Microbial bio-production of a recombinant stimuli-responsive biosurfactant.

Biosurfactants have been the subject of recent interest as sustainable alternatives to petroleum-derived compounds in areas ranging from soil remediation to personal and health care. The production of naturally occurring biosurfactants depends on the presence of complex feed sources during microbial growth and requires multicomponent enzymes for synthesis within the cells. Conversely, designed peptide surfactants can be produced recombinantly in microbial systems, enabling the generation of improved variants by simple genetic manipulation. However, inefficient downstream processing is still an obstacle for the biological production of small peptides. We present the production of the peptide biosurfactant GAM1 in recombinant E. coli. Expression was performed in fusion to maltose binding protein using chemically defined minimal medium, followed by a single-step affinity capture and enzymatic cleavage using tobacco etch virus protease. Different approaches to the isolation of peptide after cleavage were investigated, with special emphasis on rapid and simple procedures. Solvent-, acid-, and heat-mediated precipitation of impurities were successfully applied as alternatives to post-cleavage chromatographic peptide purification, and gave peptide purities exceeding 90%. Acid precipitation was the method of choice, due to its simplicity and the high purification factor and recovery rate achieved here. The functionality of the bio-produced peptide was tested to ensure that the resulting peptide biosurfactant was both surface active and able to be triggered to switch between foam-stabilizing and foam-destabilizing states.

Expression and purification of a nanostructure-forming peptide.

Peptides have recently attracted interest as building blocks for the assembly of novel functional materials including switchable surfactants, nanocoatings, hydrogels and aqueous vesicles. We expressed a beta-sheet forming peptide that has been widely studied in self-assembly processing, P(11)-2, as a monomer, dimer, tetramer and nonamer fused to an insoluble expression partner, ketosteroid isomerase, using minimal media. Expression was followed by whole cell extraction and isolation of the fusion protein to greater than 90% purity via a single immobilised metal affinity chromatography (IMAC) step. Peptides were chemically cleaved from each other and from the fusion partner, followed by acetone precipitation of the contaminating protein fragments. Pure peptide was recovered by reversed-phase HPLC. The expression level of the fusion protein decreased as the peptide concatamer number increased, as did the efficiency of the chemical cleavage, making the single-peptide process the most efficient overall. Applying this laboratory process to the single-peptide fusion protein nevertheless resulted in a pure peptide yield of greater than 30% of the expressed peptide.

Measuring bed shear stress along vegetated river beds using FST-hemispheres.

The measurement of the bed shear stress along vegetated river beds is essential for accurately predicting the water level, velocity and solute and sediment transport fluxes in computational hydroenvironmental models. Details are given herein of an experimental and theoretical study to determine the bed boundary shear stress along vegetated river beds introducing a novel field measuring method, namely the FliessWasserStammtisch (FST)-hemispheres. Although investigations have been conducted previously for sedimentary channels using the FST-hemispheres, this preliminary study is thought to be the first time that such hemispheres have been used to investigate the bed shear stresses in vegetated channels. FST-hemispheres were first developed by Statzner and Müller [1989. Standard hemispheres as indicators of flow characteristics in lotic benthos research. Freshwater Biology 21, 445-459] to act as an integrated indicator of the gross hydrodynamic stresses present near the bed. Test and validation data were found to be at least of the same order of magnitude for the stresses predicted from literature for sedimentary channels, with this study establishing the commencement of a database of calibrated FST-hemisphere laboratory data for vegetated channel beds. In a series of experiments, depths ranging from 0.1 to 0.28 m were considered, equating directly to comparable conditions in small rivers or streams. The results of this study provide a basis for enabling the FST-hemispheres to be used to evaluate the boundary shear stress for a wider range of applications in the future, including vegetated river beds.

Modelling the fate of faecal indicators in a coastal basin.

The paper describes a modelling study of near-shore coastal waters, undertaken to assess the impact of various bacterial input loads on the receiving waters in a coastal basin in the UK. Total and faecal coliforms, used as the indicators for bathing water quality under the European Union (EU) Bathing Water Directive, were numerically modelled using a 2D depth integrated hydro-environmental model. Details are given of the governing equations and solution methods used in the numerical model, together with a discussion of the recent development in faecal bacterial indicator modelling. Details are also given of a field data collection exercise, which involved initially collecting existing information on effluent input loads and followed by an intensive field survey. Using the water quality model, the mortality rate of the pathogen bacteria was investigated. Three methods were used to represent the relationship between the decay rate and the level of solar radiation including: a constant decay rate, day- and night-time decay rates and a solar radiation related time varying decay rate. Relatively close agreement between model predicted and measured total and faecal coliform concentration distributions were obtained for different day- and night-time decay rates and time varying decay rates. No significant differences were found in the optimum decay rates for total and faecal coliform levels. Finally, the impact of the individual inputs on the bathing water quality of the basin was also statistically and numerically investigated. Results showed that the River Irvine was the most significant input during high river flows, and that under these conditions the bathing waters were likely to fail to comply with the European Union Bathing Water Directive. For base river flow conditions the Meadowhead effluent input was found to be critical for both total and faecal coliform level predictions.

Decay of intestinal enterococci concentrations in high-energy estuarine and coastal waters: towards real-time T90 values for modelling faecal indicators in recreational waters.

Intestinal enterococci are the principal 'health-evidence-based' parameter recommended by WHO for the assessment of marine recreational water compliance. Understanding the survival characteristics of these organisms in nearshore waters is central to public health protection using robust modelling to effect real-time prediction of water quality at recreation sites as recently suggested by WHO and the Commission of the European Communities Previous models have more often focused on the coliform parameters and assumed two static day-time and night-time T90 values to characterise the decay process. The principal driver for enterococci survival is the received dose of irradiance from sunlight. In the water column, transmission of irradiance is determined by turbidity produced by suspended material. This paper reports the results of irradiated microcosm experiments using simulated sunlight to investigate the decay of intestinal enterococci in relatively turbid estuarine and coastal waters collected from the Severn Estuary and Bristol Channel, UK. High-turbidity estuarine waters produced a T90 value of 39.5 h. Low-turbidity coastal waters produced a much shorter T90 value of 6.6 h. In experiments receiving no irradiation, high-turbidity estuarine waters also produced a longer T90 of 65.1 h compared with corresponding low-turbidity coastal waters, T90 24.8 h. Irradiated T90 values were correlated with salinity, turbidity and suspended solids (r>0.8, p<0.001). The results suggest that enterococci decay in irradiated experiments with turbidity >200 NTU is similar to decay observed under dark conditions. Most significantly, these results suggest that modelling turbidity and or suspended solids offers a potential means of predicting T90 values in 'real-time' for discrete cells of a hydrodynamic model.

Modelling hydroenvironmental and health risk assessment parameters along the South Wales Coast.

This paper highlights the increasing concerns relating to hydroenvironmetal issues and cites recent examples of the challenges now being regularly faced by hydroenvironmetal scientists and engineers. The limitations and restrictions of both physical (or laboratory) and numerical (or computer based) hydraulic models used in the planning and management of aquatic basins are discussed. General details are given of numerical models used for flow and water quality concentration predictions in estuarine waters, with particular application to the challenges occurring along the South Wales coast. A highly accurate and non-diffusive finite difference scheme that solves the transport equation for predicting water quality indicators and suspended sediment concentration distributions is also discussed. In particular, details are outlined of the extension of the water quality indicators of faecal coliforms, as required to comply with the EU Bathing Water Directive, to predict health risk assessment, in the form of predicting the risk of gastroenteritis. Three example research projects along the South Wales coast are described; the projects involve the application of two-dimensional and three-dimensional hydroenvironmetal models to predict flow patterns and water quality indicator organism distributions in the coastal receiving waters. These studies include: (i) a curvilinear finite difference approach to modelling flows in the Bristol Channel, (ii) coastal health risk predictions in Swansea Bay using combined water quality and epidemiological models, and (iii) combined sewer overflow discharges into Cardiff Bay.

Predicting near-shore coliform bacteria concentrations using ANNS.

Details are given of the application of Artificial Neural Networks (ANNs) to predicting the compliance of bathing waters along the coastline of the Firth of Clyde, situated in the south west of Scotland, UK. Water quality data collected at 7 locations during 1990-2000 were used to set up the neural networks. In this study faecal coliforms were used as a water quality indicator, i.e. output, and rainfall, river discharge, sunlight and tidal condition were used as input of these networks. In general, river discharge and tidal ranges were found to be the most important parameters that affect the coliform concentration levels. For compliance points close to the meteorological station, the influence of rainfall was found to be relatively significant to the concentration levels.

Hydro-environmental modelling for bathing water compliance of an estuarine basin.

In recent years, considerable investment has been committed to sewerage infrastructure and new sewage treatment plants in the catchment surrounding an estuarine basin along the north-west coast of England. Although this capital investment has resulted in a marked reduction in the input of bacterial loads, relatively high counts of faecal indicator organisms are still being encountered in the coastal receiving waters, and the local bathing waters continue to fail on occasions to comply with the European Community (EC) Bathing Water Directive (1976) mandatory standards. Details are given herein of a comprehensive modelling study aimed at quantifying the impact of various bacterial inputs into the estuary and surrounding coastal waters on the bathing water quality. The model domain includes the coastal area and the entire estuary (namely the Ribble) up to the tidal limits of its tributaries. Faecal coliforms have been used as the main water quality indicator organisms. The numerical model developed for this study combines a depth integrated two-dimensional coastal model and a cross-sectionally integrated one-dimensional river model, and is capable of predicting water surface elevations, velocity fields and faecal coliform concentration distributions across the entire model domain. The hydrodynamic model was calibrated using water level and velocity measurements from three surveys and then validated against measured data from three other surveys. In order to predict the faecal coliform concentration distributions, variable faecal coliform decay rates were used, i.e. different values of decay rates were applied to the coastal and riverine waters, for day- and nighttime, and for wet and dry weather conditions. The maximum and minimum decay rates used were 2.32/day and 0.71/day for the dry and wet weather surveys, respectively. The model was then applied to (i) assess the impact of previous discharge strategies and investigate the effectiveness of future capital investment works and (ii) predict the impact of a range of strategic options, including: the effects of adding UV treatment, constructing storm water storage tanks and incorporating various combined sewer overflow (CSO) discharge scenarios for different weather conditions.

Emission of chiral organochlorine pesticides from agricultural soils in the cornbelt region of the U.S.

Several organochlorine pesticides are chiral molecules manufactured as racemic mixtures. Past research has shown that selective degradation of pesticide enantiomers by microorganisms occurs resulting in nonracemic signatures in soils. In this work, volatilization of chiral pesticides from soil was investigated to determine if enantioselective breakdown in soils could be used as a source signature to track releases of chiral pesticides to the atmosphere. Air samples were taken directly above agricultural soils at several sites, and enantiomeric signatures were found to be nonracemic following patterns found in the soil. A follow up study at one site showed that for most compounds concentration decreased with increasing height above the soil, while enantiomer fractions for chiral pesticides were similar to that found in the soil, signifying the soil as a source to the air. The enantiomer fractions of ambient air samples from rural nonagricultural areas in the region were also found to be nonracemic.

Synthesis of C-terminal glycopeptides from resin-bound glycosyl azides via a modified Staudinger reaction.

The solid-phase synthesis of glycopeptides containing the sugar at the C-terminus is reported. The method is demonstrated on a model, the endogenous antinociceptive peptide Leu-enkephalin. 2,3,4-Tri-O-acetyl-1-azido-1-deoxy-beta-D-glucopyranuronic acid was synthesized and immobilized onto a variety of derivatized resins. Conjugation of the first amino acid was accomplished by reaction of the resin-bound glycosyl azide with an activated amino acid, in one step, via a modified Staudinger reaction. Standard solid-phase peptide synthesis then resulted in the desired amide-linked glycopeptide. Reaction conditions and reagents for the glycosylation were varied to optimize the yield and purity of the product. The optimum conditions were found to be the use of a 4-fold molar excess of activated amino acid and 3-fold excess of tri-n-butylphosphine in tetrahydrofuran. This methodology is generally applicable to most peptide sequences and is compatible with both Boc- and Fmoc- synthetic strategies on a variety of resins.

Chemical treatment of Escherichia coli: 3. Selective extraction of a recombinant protein from cytoplasmic inclusion bodies in intact cells.

In previous parts of this study we developed procedures for the high-efficiency chemical extraction of soluble and insoluble protein from intact Escherichia coli cells. Although high yields were obtained, extraction of recombinant protein directly from cytoplasmic inclusion bodies led to low product purity due to coextraction of soluble contaminants. In this work, a two-stage procedure for the selective extraction of recombinant protein at high efficiency and high purity is reported. In the first stage, inclusion-body stability is promoted by the addition of 15 mM 2-hydroxyethyldisulfide (2-HEDS), also known as oxidized beta-mercaptoethanol, to the permeabilization buffer (6 M urea + 3 mM ethylenediaminetetraacetate [EDTA]). 2-HEDS is an oxidizing agent believed to promote disulfide bond formation, rendering the inclusion body resistant to solubilization in 6 M urea. Contaminating proteins are separated from the inclusion-body fraction by centrifugation. In the second stage, disulfide bonds are readily eliminated by including reducing agent (20 mM dithiothreitol [DTT]) into the permeabilization buffer. Extraction using this selective two-stage process yielded an 81% (w/w) recovery of the recombinant protein Long-R3-IGF-I from inclusion bodies located in the cytoplasm of intact E. coli, at a purity of 46% (w/w). This was comparable to that achieved by conventional extraction (mechanical disruption followed by centrifugation and solubilization). A pilot-scale procedure was also demonstrated using a stirred reactor and diafiltration. This is the first reported study that achieves both high extraction efficiency and selectivity by the chemical treatment of cytoplasmic inclusion bodies in intact bacterial cells.