Biallelic EPCAM deletions induce tissue-specific DNA repair deficiency and cancer predisposition

We report a case of Mismatch Repair Deficiency (MMRD) caused by germline homozygous EPCAM deletion leading to tissue-specific loss of MSH2. Through the use of patient-derived cells and organoid technologies, we performed stepwise in vitro differentiation of colonic and brain organoids from reprogrammed EPCAMdel iPSC derived from patient fibroblasts. Differentiation of iPSC to epithelial-colonic organoids exhibited continuous increased EPCAM expression and hypermethylation of the MSH2 promoter. This was associated with loss of MSH2 expression, increased mutational burden, MMRD signatures and MS-indel accumulation, the hallmarks of MMRD. In contrast, maturation into brain organoids and examination of blood and fibroblasts failed to show similar processes, preserving MMR proficiency. The combined use of iPSC, organoid technologies and functional genomics analyses highlights the potential of cutting-edge cellular and molecular analysis techniques to define processes controlling tumorigenesis and uncovers a new paradigm of tissue-specific MMRD, which affects the clinical management of these patients.

Ocean climate and hydrodynamics drive decadal shifts in Northeast Atlantic dinoflagellates

The abundance of large marine dinoflagellates has declined in the North Sea since 1958. Although hypotheses have been proposed to explain this diminution (increasing temperature and wind), the mechanisms behind this pattern have thus far remained elusive. In this article, we study the long-term changes in dinoflagellate biomass and biodiversity in relation to hydro-climatic conditions and circulation within the North Atlantic. Our results show that the decline in biomass has paralleled an increase in biodiversity caused by a temperature-induced northward movement of subtropical taxa along the European shelf-edge, and facilitated by changes in oceanic circulation (subpolar gyre contraction). However, major changes in North Atlantic hydrodynamics in the 2010s (subpolar gyre expansion and low-salinity anomaly) stopped this movement, which triggered a biodiversity collapse in the North Sea. Further, North Sea dinoflagellate biomass remained low because of warming. Our results, therefore, reveal that regional climate warming and changes in oceanic circulation strongly influenced shifts in dinoflagellate biomass and biodiversity.

Molecular typing of Leptospira spp. in farmed and wild mammals reveals new host-serovar associations in New Zealand

AIMS

To apply molecular typing to DNA isolated from historical samples to determine Leptospira spp. infecting farmed and wild mammals in New Zealand.

MATERIALS AND METHODS

DNA samples used in this study were extracted from urine, serum or kidney samples (or Leptospira spp. cultures isolated from them) collected between 2007 and 2017 from a range of domestic and wildlife mammalian species as part of different research projects at Massey University. Samples were included in the study if they met one of three criteria: samples that tested positive with a lipL32 PCR for pathogenic Leptospira; samples that tested negative by lipL32 PCR but were recorded as positive to PCR for pathogenic Leptospira in the previous studies; or samples that were PCR-negative in all studies but were from animals with positive agglutination titres against serogroup Tarassovi. DNA samples were typed using PCR that targeted either the glmU or gyrB genetic loci. The resulting amplicons were sequenced and typed relative to reference sequences.

RESULTS

We identified several associations between mammalian hosts and Leptospira strains/serovars that had not been previously reported in New Zealand. Leptospira borgpetersenii strain Pacifica was found in farmed red deer (Cervus elaphus) samples, L. borgpetersenii serovars Balcanica and Ballum were found in wild red deer samples, Leptospira interrogans serovar Copenhageni was found in stoats (Mustela erminea) and brushtail possums (Trichosurus vulpecula), and L. borgpetersenii was found in a ferret (Mustela putorius furo). Furthermore, we reconfirmed previously described associations including dairy cattle with L. interrogans serovars Copenhageni and Pomona and L. borgpetersenii serovars Ballum, Hardjo type bovis and strain Pacifica, sheep with L. interrogans serovar Pomona and L. borgpetersenii serovar Hardjo type bovis, brushtail possum with L. borgpetersenii serovar Balcanica, farmed deer with L. borgpetersenii serovar Hardjo type bovis and hedgehogs (Erinaceus europaeus) with L. borgpetersenii serovar Ballum.

CONCLUSIONS

This study provides an updated summary of host-Leptospira associations in New Zealand and highlights the importance of molecular typing. Furthermore, strain Pacifica, which was first identified as Tarassovi using serological methods in dairy cattle in 2016, has circulated in animal communities since at least 2007 but remained undetected as serology is unable to distinguish the different genotypes.

CLINICAL RELEVANCE

To date, leptospirosis in New Zealand has been diagnosed with serological typing, which is deficient in typing all strains in circulation. Molecular methods are necessary to accurately type strains of Leptospira spp. infecting mammals in New Zealand.

Plus Sutures for preventing surgical site infection: a systematic review of clinical outcomes with economic and environmental models

BACKGROUND

Surgical site infections (SSIs) represent ~ 20% of all hospital-acquired infections in surgical patients and are associated with prolonged hospital stay, admission to intensive care, and mortality. We conducted a systematic review with economic and environmental models to assess whether triclosan-coated sutures (Plus Sutures) provide benefits over non-coated sutures in the reduction of SSI risk.

METHODS

Searches were conducted in fifteen databases. A total of 1,991 records were retrieved. Following deduplication and screening by two independent reviewers, 31 randomized controlled trials in adults and children were included in the review. Similarity of the studies was assessed by narrative review and confirmed by quantitative assessment. A fixed effects meta-analysis of SSI incidence model including all groups of patients estimated a risk ratio of 0.71 (95% confidence interval: 0.64 to 0.79) indicating those in the Plus Sutures group had a 29% reduction in the risk of developing an SSI compared with those in the control group (p < 0.001). Safety outcomes were analysed qualitatively.

RESULTS

The economic model estimated the use of Plus Sutures to result in average cost savings of £13.63 per patient. Plus Sutures remained cost-saving in all subgroup analyses with cost-savings ranging between £11 (clean wounds) and £140 (non-clean wounds). The environmental impact of SSI is substantial, and the model suggests that the introduction of Plus Sutures could result in potential environmental benefits.

CONCLUSIONS

The evidence suggests that Plus Sutures are associated with a reduced incidence of SSI across all surgery types alongside cost savings when compared with standard sutures.

Comparison of mechanical properties and host tissue response to OviTex™ and Strattice™ surgical meshes

PURPOSE

This study compared the in vitro/benchtop and in vivo mechanical properties and host biologic response to ovine rumen-derived/polymer mesh hybrid OviTex™ with porcine-derived acellular dermal matrix Strattice™ Firm.

METHODS

OviTex 2S Resorbable (OviTex 2S-R) and Strattice morphology were examined in vitro using histology and scanning electron microscopy; mechanical properties were assessed via tensile test; in vivo host biologic response and explant mechanics were evaluated in a rodent subcutaneous model. Separately, OviTex 1S Permanent (OviTex 1S-P) and Strattice were evaluated in a primate abdominal wall repair model.

RESULTS

OviTex 2S-R demonstrated layer separation, whereas Strattice retained its structural integrity and demonstrated higher maximum load than OviTex 2S-R out-of-package (124.8 ± 11.1 N/cm vs 37.9 ± 5.5 N/cm, p < 0.001), 24 h (55.7 ± 7.4 N/cm vs 5.6 ± 3.8 N/cm, p < 0.001), 48 h (45.3 ± 14.8 N/cm vs 2.8 ± 2.6 N/cm, p = 0.003), and 72 h (29.2 ± 10.5 N/cm vs 3.2 ± 3.1 N/cm, p = 0.006) following collagenase digestion. In rodents, inflammatory cell infiltration was observed between OviTex 2S-R layers, while Strattice induced a minimal inflammatory response. Strattice retained higher maximum load at 3 (46.3 ± 27.4 N/cm vs 9.5 ± 3.2 N/cm, p = 0.041) and 6 weeks (28.6 ± 14.1 N/cm vs 7.0 ± 3.0 N/cm, p = 0.029). In primates, OviTex 1S-P exhibited loss of composite mesh integrity whereas Strattice integrated into host tissue with minimal inflammation and retained higher maximum load at 1 month than OviTex 1S-P (66.8 ± 43.4 N/cm vs 9.6 ± 4.4 N/cm; p = 0.151).

CONCLUSIONS

Strattice retained greater mechanical strength as shown by lower susceptibility to collagenase degradation than OviTex 2S-R in vitro, as well as higher maximum load and improved host biologic response than OviTex 2S-R in rodents and OviTex 1S-P in primates.

Towards optimal use of antithrombotic therapy of people with cancer at the end of life: A research protocol for the development and implementation of the SERENITY shared decision support tool

BACKGROUND

Even though antithrombotic therapy has probably little or even negative effects on the well-being of people with cancer during their last year of life, deprescribing antithrombotic therapy at the end of life is rare in practice. It is often continued until death, possibly resulting in excess bleeding, an increased disease burden and higher healthcare costs.

METHODS

The SERENITY consortium comprises researchers and clinicians from eight European countries with specialties in different clinical fields, epidemiology and psychology. SERENITY will use a comprehensive approach combining a realist review, flash mob research, epidemiological studies, and qualitative interviews. The results of these studies will be used in a Delphi process to reach a consensus on the optimal design of the shared decision support tool. Next, the shared decision support tool will be tested in a randomised controlled trial. A targeted implementation and dissemination plan will be developed to enable the use of the SERENITY tool across Europe, as well as its incorporation in clinical guidelines and policies. The entire project is funded by Horizon Europe.

RESULTS

SERENITY will develop an information-driven shared decision support tool that will facilitate treatment decisions regarding the appropriate use of antithrombotic therapy in people with cancer at the end of life.

CONCLUSIONS

We aim to develop an intervention that guides the appropriate use of antithrombotic therapy, prevents bleeding complications, and saves healthcare costs. Hopefully, usage of the tool leads to enhanced empowerment and improved quality of life and treatment satisfaction of people with advanced cancer and their care givers.

Phytoplankton life strategies, phenological shifts and climate change in the North Atlantic Ocean from 1850 to 2100

Significant phenological shifts induced by climate change are projected within the phytoplankton community. However, projections from current Earth System Models (ESMs) understandably rely on simplified community responses that do not consider evolutionary strategies manifested as various phenotypes and trait groups. Here, we use a species-based modelling approach, combined with large-scale plankton observations, to investigate past, contemporary and future phenological shifts in diatoms (grouped by their morphological traits) and dinoflagellates in three key areas of the North Atlantic Ocean (North Sea, North-East Atlantic and Labrador Sea) from 1850 to 2100. Our study reveals that the three phytoplanktonic groups exhibit coherent and different shifts in phenology and abundance throughout the North Atlantic Ocean. The seasonal duration of large flattened (i.e. oblate) diatoms is predicted to shrink and their abundance to decline, whereas the phenology of slow-sinking elongated (i.e. prolate) diatoms and of dinoflagellates is expected to expand and their abundance to rise, which may alter carbon export in this important sink region. The increase in prolates and dinoflagellates, two groups currently not considered in ESMs, may alleviate the negative influence of global climate change on oblates, which are responsible of massive peaks of biomass and carbon export in spring. We suggest that including prolates and dinoflagellates in models may improve our understanding of the influence of global climate change on the biological carbon cycle in the oceans.

Design and Synthesis of Functionally Active 5-Amino-6-Aryl Pyrrolopyrimidine Inhibitors of Hematopoietic Progenitor Kinase 1

Immune activating agents represent a valuable class of therapeutics for the treatment of cancer. An area of active research is expanding the types of these therapeutics that are available to patients via targeting new biological mechanisms. Hematopoietic progenitor kinase 1 (HPK1) is a negative regulator of immune signaling and a target of high interest for the treatment of cancer. Herein, we present the discovery and optimization of novel amino-6-aryl pyrrolopyrimidine inhibitors of HPK1 starting from hits identified via virtual screening. Key components of this discovery effort were structure-based drug design aided by analyses of normalized B-factors and optimization of lipophilic efficiency.

Measuring the impact of deprivation on learning difficulties and behaviour among infants born preterm: A cohort study

BACKGROUND

Preterm birth and social deprivation are known risk factors for learning difficulties. However there has been little work looking into the interaction between these two risks. We aimed to identify if children born preterm to families with higher levels of social deprivation are disproportionately more likely to have learning difficulties than those with lower levels of social deprivation.

METHODS

Data from the RANOPS (Respiratory And Neurological Outcomes in children born Preterm Study) was used to assess prevalence of learning difficulties. The effects of preterm birth and deprivation were reviewed. Multi-level logistic regression models were used to examine if gestational age and deprivation impacts interacted after adjustment for possible confounders. Primary outcome measure was parent-reported learning difficulties. Secondary outcome measures were parent-reported behavioural problems and a statement of special educational need.

RESULTS

We investigated the developmental outcomes of 6,691 infants with a median age of 5 years at time of survey (IQR 5). Deprivation decile (OR 1.08 (1.03,1.12)) and preterm birth (OR 2.67 (2.02,3.53)) were both associated with increased risk of learning difficulties. There was little evidence for any interaction between preterm birth and deprivation (p = 0.298) and the risk of learning difficulties.

CONCLUSIONS

Deprivation and preterm birth have significant associations with learning difficulties. While deprivation does not appear to have potentiated the impact of preterm birth, preterm infants in the most deprived areas have the highest risk of learning difficulties with almost 1 in 3 extremely premature infants with a learning difficulty in the most deprived areas.

A Health Inequalities Impact Assessment of the surveillance of COVID-19 in asymptomatic patients attending dental settings in Scotland

INTRODUCTION

A key aspect of the public health response to COVID-19 in Scotland was enhanced community surveillance, including testing in dental settings. Across Scotland, dental settings offered patients over 5-years-old the opportunity to participate in community surveillance of COVID-19.

METHODS

A Health Inequalities Impact Assessment (HIIA) was conducted to understand the differential impacts the programme would have on the population and to improve the accessibility of the programme. HIIA is a tool to allow the assessment, understanding, and mitigation of impacts on people of a proposed policy or practice. It fulfils an organisational duty to meet the requirements of the Equality Act and Fairer Scotland Duty. The HIIA was conducted rapidly in parallel with the programme development. An action research approach included an online workshop, consultation, review of population data and a literature search.

RESULTS

Adjustments were required to improve the programme's accessibility. Stakeholders, including dental teams from across Scotland were involved in the consultation and brought their front-line experience in different settings. Common issues identified included digital literacy and access, language and cultural barriers to participation, and issues relating to the implications of a positive COVID-19 result. Literature indicated limited evidence on the acceptability, accessibility, and equity of asymptomatic COVID-19 surveillance.

CONCLUSION

This HIIA was conducted during the COVID-19 pandemic. As an example of good practice in tackling inequalities in access to programmes it should represent the benchmark for other similar initiatives.

Realist analysis of whether emergency departments with primary care services generate 'provider-induced demand'

Background

It is not known whether emergency departments (EDs) with primary care services influence demand for non-urgent care (‘provider-induced demand’). We proposed that distinct primary care services in EDs encourages primary care demand, whereas primary care integrated within EDs may be less likely to cause additional demand. We aimed to explore this and explain contexts (C), mechanisms (M) and outcomes (O) influencing demand.

Methods

We used realist evaluation methodology and observed ED service delivery. Twenty-four patients and 106 staff members (including Clinical Directors and General Practitioners) were interviewed at 13 EDs in England and Wales (240 hours of observations across 30 days). Field notes from observations and interviews were analysed by creating ‘CMO’ configurations to develop and refine theories relating to drivers of demand.

Results

EDs with distinct primary care services were perceived to attract demand for primary care because services were visible, known or enabled direct access to health care services. Other influencing factors included patients’ experiences of accessing primary care, community care capacity, service design and population characteristics.

Conclusions

Patient, local-system and wider-system factors can contribute to additional demand at EDs that include primary care services. Our findings can inform service providers and policymakers in developing strategies to limit the effect of potential influences on additional demand when demand exceeds capacity.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12873-022-00709-2.

Amoebic crab disease (ACD) in edible crab Cancer pagurus from the English Channel, UK

The genera Paramoeba and Neoparamoeba (Amoebozoa, Dactylopodida, Paramoebidae) include well-known opportunistic pathogens associated with fish (N. peruans; amoebic gill disease), lobsters, molluscs and sea urchins, but only rarely with crabs (grey crab disease of blue crabs). Following reports of elevated post-capture mortality in edible crabs Cancer pagurus captured from a site within the English Channel fishery in the UK, a novel disease (amoebic crab disease, ACD) was detected in significant proportions of the catch. We present histopathological, transmission electron microscopy and molecular phylogenetic data, showing that this disease is defined by colonization of haemolymph, connective tissues and fixed phagocytes by amoeboid cells, leading to tissue destruction and presumably death in severely diseased hosts. The pathology was strongly associated with a novel amoeba with a phylogenetic position on 18S rRNA gene trees robustly sister to Janickina pigmentifera (which groups within the current circumscription of Paramoeba/Neoparamoeba), herein described as Janickina feisti n. sp. We provide evidence that J. feisti is associated with ACD in 50% of C. pagurus sampled from the mortality event. A diversity of other paramoebid sequence types, clustering with known radiations of N. pemaquidensis and N. aestuarina and a novel N. aestuarina sequence type, was detected by PCR in most of the crabs investigated, but their detection was much less strongly associated with clinical signs of disease. The discovery of ACD in edible crabs from the UK is discussed relative to published historical health surveys for this species.

Evaluation of prognostic risk models for postoperative pulmonary complications in adult patients undergoing major abdominal surgery: a systematic review and international external validation cohort study

BACKGROUND

Stratifying risk of postoperative pulmonary complications after major abdominal surgery allows clinicians to modify risk through targeted interventions and enhanced monitoring. In this study, we aimed to identify and validate prognostic models against a new consensus definition of postoperative pulmonary complications.

METHODS

We did a systematic review and international external validation cohort study. The systematic review was done in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. We searched MEDLINE and Embase on March 1, 2020, for articles published in English that reported on risk prediction models for postoperative pulmonary complications following abdominal surgery. External validation of existing models was done within a prospective international cohort study of adult patients (≥18 years) undergoing major abdominal surgery. Data were collected between Jan 1, 2019, and April 30, 2019, in the UK, Ireland, and Australia. Discriminative ability and prognostic accuracy summary statistics were compared between models for the 30-day postoperative pulmonary complication rate as defined by the Standardised Endpoints in Perioperative Medicine Core Outcome Measures in Perioperative and Anaesthetic Care (StEP-COMPAC). Model performance was compared using the area under the receiver operating characteristic curve (AUROCC).

FINDINGS

In total, we identified 2903 records from our literature search; of which, 2514 (86·6%) unique records were screened, 121 (4·8%) of 2514 full texts were assessed for eligibility, and 29 unique prognostic models were identified. Nine (31·0%) of 29 models had score development reported only, 19 (65·5%) had undergone internal validation, and only four (13·8%) had been externally validated. Data to validate six eligible models were collected in the international external validation cohort study. Data from 11 591 patients were available, with an overall postoperative pulmonary complication rate of 7·8% (n=903). None of the six models showed good discrimination (defined as AUROCC ≥0·70) for identifying postoperative pulmonary complications, with the Assess Respiratory Risk in Surgical Patients in Catalonia score showing the best discrimination (AUROCC 0·700 [95% CI 0·683-0·717]).

INTERPRETATION

In the pre-COVID-19 pandemic data, variability in the risk of pulmonary complications (StEP-COMPAC definition) following major abdominal surgery was poorly described by existing prognostication tools. To improve surgical safety during the COVID-19 pandemic recovery and beyond, novel risk stratification tools are required.

FUNDING

British Journal of Surgery Society.

Migraine in the emergency department: A retrospective evaluation of the characteristics of attendances in a major city hospital in the United Kingdom

Introduction:

Detailed Emergency Department attendance data for migraine are needed for service redesign.

Methods:

A service evaluation was undertaken, classifying adult emergency department headache attendances using the International Classification of Headache Disorders migraine C-E criteria, evaluating attendance characteristics.

Results:

Migraine/Probable migraine diagnosis was documented in 58% but coded in 24% attendances by ED clinicians. 29% of patients used no analgesia before attending, 43% attended ≥4 days after onset and 19% arrived by ambulance.

Conclusion:

This evaluation highlights sub-optimal acute management and discrepancy between migraine coding and diagnosis contributing to underreporting. We recommend further evaluation of identified cohorts and headache proforma use.

A Digital Mechanistic Workflow for Predicting Solvent-Mediated Crystal Morphology: The α and β Forms of l-Glutamic Acid

The solvent-mediated crystal morphologies of the α and β polymorphic forms of l-glutamic acid are presented. This work applies a digital mechanistically based workflow that encompasses calculation of the crystal lattice energy and its constituent intermolecular synthons, their interaction energies, and their key role in understanding and predicting crystal morphology as well as assessing the surface chemistry, topology, and solvent binding on crystal habit growth surfaces. Through a comparison between the contrasting morphologies of the conformational polymorphs of l-glutamic acid, this approach highlights how the interfacial chemistry of organic crystalline materials and their inherent anisotropic interactions with their solvation environments direct their crystal habit with potential impact on their further downstream processing behavior.

Clinical severity of RSV bronchiolitis

Background

Studies comparing the severity of respiratory syncytial virus (RSV) bronchiolitis to other viruses are inconclusive. Our study aimed to compare the severity of bronchiolitis according to the virus.

Methods

Data were collected from 1152 infants under one year of age admitted to Children's hospital for Wales, over the winter months of 2014–2020. The cohort was divided based on the virus detected: RSV, RSV with another virus, or other virus. Using t tests and Fisher exact statistical test, the groups were compared based on length of hospital stay, admissions PICU/HDU, intubations, and need of nasogastric (NG) nutritional support.

Results

Fifty‐six percent throat swabs were RSV positive, 15% had RSV with another virus, and 29% had only another virus. Children positive for RSV had statistically longer hospital admissions and were more likely to need NG nutrition; however, there was no difference between number of PICU/HDU admissions or intubations. The RSV group and RSV with another virus group had no statistical differences.

A102 INDICATION FOR ENDOSCOPIC RETROGRADE CHOLANGIOPANCREATOGRAPHY AND ASSOCIATION WITH HEMORRHAGE: A SYSTEMATIC REVIEW AND META-ANALYSIS

Background

Hemorrhage is a complication associated with up to 2% of cases of Endoscopic Retrograde Cholangiopancreatography (ERCP), most commonly following sphincterotomy. Studies investigating risk factors associated with hemorrhage, such as ERCP indication, have been conflicting.

Aims

We performed a systematic review and meta-analysis to determine the association between the indication for ERCP and ERCP-associated hemorrhage.

Methods

A systematic search of MEDLINE, EMBASE, and CENTRAL was done from inception until September 2021 for studies reporting on factors associated with ERCP-associated hemorrhage (both immediate and delayed) in adults. Exclusion criteria included: pediatric patients, no outcome of interest, did not investigate hemorrhage risk factors, inappropriate study design (basic science, reviews, and case reports/series), or if no English text was available. A DerSimonian and Laird random-effects meta-analysis was performed to generate pooled Odds Ratios (OR) with 95% Confidence Intervals (CIs) for each procedural indication in relation to hemorrhage.

Results

952 records were identified of which 17 were included in our quantitative analysis. Common indications included acute cholangitis, choledocholithiasis, Sphincter of Oddi dysfunction (SOD), acute pancreatitis, chronic pancreatitis, and malignancy-associated duct obstruction. Rates of hemorrhage varied in the included studies (median 2.2%; IQR 1.7–6.9). Sphincterotomy rates also differed in the included studies (median 100%; IQR 71.1–100). Five studies did not report on antiplatelet or anticoagulant use with the remaining reporting varying rates of antiplatelet (median 8.3%; IQR 0–26.5) and anticoagulant (median 0.8%; IQR 0–2.25) use. Hemorrhage was significantly associated with acute cholangitis (OR 2.48; 95% CI 1.62–3.78) and choledocholithiasis (OR 1.76; 95% CI 1.06–2.94) but not SOD (OR 1.38; 95% CI 0.74–2.58), malignancy (OR 0.68; 95% CI 0.29–1.59), acute pancreatitis (OR 1.08; 95% CI 0.30–3.82), or chronic pancreatitis (OR 0.56; 95% CI 0.16–1.99).

Conclusions

Acute cholangitis and choledocholithiasis were associated with increased hemorrhage, whereas SOD, malignancy, acute pancreatitis, and chronic pancreatitis were not. Providers should consider procedural indication when counselling patients on hemorrhage risk in ERCP.

Funding Agencies

None

Stepping stones towards Antarctica: Switch to southern spawning grounds explains an abrupt range shift in krill

Poleward range shifts are a global-scale response to warming, but these vary greatly among taxa and are hard to predict for individual species, localized regions or over shorter (years to decadal) timescales. Moving poleward might be easier in the Arctic than in the Southern Ocean, where evidence for range shifts is sparse and contradictory. Here, we compiled a database of larval Antarctic krill, Euphausia superba and, together with an adult database, it showed how their range shift is out of step with the pace of warming. During a 70-year period of rapid warming (1920s-1990s), distribution centres of both larvae and adults in the SW Atlantic sector remained fixed, despite warming by 0.5-1.0°C and losing sea ice. This was followed by a hiatus in surface warming and ice loss, yet during this period the distributions of krill life stages shifted greatly, by ~1000 km, to the south-west. Understanding the mechanism of such step changes is essential, since they herald system reorganizations that are hard to predict with current modelling approaches. We propose that the abrupt shift was driven by climatic controls acting on localized recruitment hotspots, superimposed on thermal niche conservatism. During the warming hiatus, the Southern Annular Mode index continued to become increasingly positive and, likely through reduced feeding success for larvae, this led to a precipitous decline in recruitment from the main reproduction hotspot along the southern Scotia Arc. This cut replenishment to the northern portion of the krill stock, as evidenced by declining density and swarm frequency. Concomitantly, a new, southern reproduction area developed after the 1990s, reinforcing the range shift despite the lack of surface warming. New spawning hotspots may provide the stepping stones needed for range shifts into polar regions, so planning of climate-ready marine protected areas should include these key areas of future habitat.

183 Improving Wellbeing Among UK Doctors Redeployed During Thecovid-19 Pandemic

Background

In response to the COVID-19, the NHS has implemented significant workforce changes to manage the increased and changing demand on healthcare services. We aimed to investigate the impact of such changes on the wellbeing of redeployed doctors.

Method

We conducted a survey at three NHS trusts over 2 weeks during the peak of the pandemic, asking redeployed doctors to rate their morale, work–life balance, perceived support and safety, and to voice concerns.

Results

172 redeployed doctors responded to the survey. On exploring morale, 114 (66.3%) respondents felt confident in their new role, 113 (65.7%) felt satisfied or neutral with their new role and only 54 (31.4%) felt stressed at work. 114 (66.3%) doctors felt valued by their team and 136 (79%) felt valued by the general public. 111 (64.5%) had noticed an increase in the length of breaks and 153 (89%) felt that their rotas provided sufficient respite. 95 respondents (55.2%) did not feel confident in the Public Health personal protective equipment (PPE) guidance and similarly 94 (54.7%) did not feel safe while wearing PPE. The three most common concerns were training opportunities – 105 (61%), PPE – 99 (57.6%) and family health – 95 (55.2%).

Conclusions

Our findings suggest that, among the doctors surveyed, morale is higher than might be expected, with doctors feeling valued, confident, and well rested in their new role. Concerns about training opportunities/career progression, PPE and family safety need to be addressed to minimise the adverse effects on doctor’s wellbeing due to redeployment.

1373 Semi-Elective Trauma Patients Pathway and Medical Clerking Proforma, Closed Loop Audit

Introduction

Semi-elective Trauma care is a service provided by the Trauma and Orthopaedic department for patients who sustain fractures to the upper and lower limbs requiring surgical intervention, are still ambulatory and can be cared for safely at home until the date of operation.

Aim

To assess patients’ referral pathway and clerking documentation against the Standards for the Clinical Structure and Content of Patient Records, published by the RCSEng.

Method

We performed a closed loop audit on the clerking documentation and the referral pathway for these patients. We collected data retrospectively for three months, assessing the clerking documentation against the guidelines. The data was analysed and presented at our Clinical Governance meeting. We then implemented the Semi-Elective Trauma Pathway and the Medical Clerking Proforma. Afterwards, data was collected prospectively to complete the audit cycle.

Results

A sum of 181 patient were included. Before the use of our changes, only 36% of patients had a complete clerking documentation, with two cases of near misses, and no comprehensive referral pathway for these patients. Post implementation of the Pathway and the Clerking Proforma, 88% of patients had complete clerking documentation, no near misses and 95% of them went properly through the pathway we introduced.

Conclusions

These patients present an important part of any trauma list. This Audit shows that having a comprehensive referral pathway and a clerking proforma will make sure that patients will have full medical history taken and are ready for the operation on the day of surgery and decrease the number of near misses.

SARS-CoV-2 Positivity in Asymptomatic-Screened Dental Patients

Enhanced community surveillance is a key pillar of the public health response to coronavirus disease 2019 (COVID-19). Asymptomatic carriage of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a potentially significant source of transmission, yet remains relatively poorly understood. Disruption of dental services continues with significantly reduced capacity. Ongoing precautions include preappointment and/or at appointment COVID-19 symptom screening and use of enhanced personal protective equipment (PPE). This study aimed to investigate SARS-CoV-2 infection in dental patients to inform community surveillance and improve understanding of risks in the dental setting. Thirty-one dental care centers across Scotland invited asymptomatic-screened patients aged over 5 y to participate. Following verbal consent and completion of sociodemographic and symptom history questionnaire, trained dental teams took a combined oropharyngeal and nasal swab sample using standardized Viral Transport Medium-containing test kits. Samples were processed by the Lighthouse Lab and patients informed of their results by SMS/email with appropriate self-isolation guidance in the event of a positive test. All positive cases were successfully followed up by the national contact tracing program. Over a 13-wk period (from August 3, 2020, to October 31, 2020), 4,032 patients, largely representative of the population, were tested. Of these, 22 (0.5%; 95% CI, 0.5%-0.8%) tested positive for SARS-CoV-2. The positivity rate increased over the period, commensurate with uptick in community prevalence identified across all national testing monitoring data streams. To our knowledge, this is the first report of a COVID-19 testing survey in asymptomatic-screened patients presenting in a dental setting. The positivity rate in this patient group reflects the underlying prevalence in community at the time. These data are a salient reminder, particularly when community infection levels are rising, of the importance of appropriate ongoing infection prevention control and PPE vigilance, which is relevant as health care team fatigue increases as the pandemic continues. Dental settings are a valuable location for public health surveillance.

North Atlantic warming over six decades drives decreases in krill abundance with no associated range shift

In the North Atlantic, euphausiids (krill) form a major link between primary production and predators including commercially exploited fish. This basin is warming very rapidly, with species expected to shift northwards following their thermal tolerances. Here we show, however, that there has been a 50% decline in surface krill abundance over the last 60 years that occurred in situ, with no associated range shift. While we relate these changes to the warming climate, our study is the first to document an in situ squeeze on living space within this system. The warmer isotherms are shifting measurably northwards but cooler isotherms have remained relatively static, stalled by the subpolar fronts in the NW Atlantic. Consequently the two temperatures defining the core of krill distribution (7–13 °C) were 8° of latitude apart 60 years ago but are presently only 4° apart. Over the 60 year period the core latitudinal distribution of euphausiids has remained relatively stable so a ‘habitat squeeze’, with loss of 4° of latitude in living space, could explain the decline in krill. This highlights that, as the temperature warms, not all species can track isotherms and shift northward at the same rate with both losers and winners emerging under the ‘Atlantification’ of the sub-Arctic.

Martin Edwards et al. use data spanning from 1958–2017 from the Continuous Plankton Recorder Survey of the North Atlantic Ocean to examine krill distribution and abundance in conjunction with sea surface temperatures and show a 50% decline in surface krill abundance with no associated range shift. These data show that where the northern and southern distributions were previously separated by 8° of latitude, they are now separated by 4°, indicating a warming-induced range constriction.

421 Intrapelvic Protrusion of a Femoral Head in A Ceramic-on-Ceramic Total Hip Replacement, A Case Report

Introduction

Ceramic on ceramic bearing in Total Hip Replacement (THR) is associated with a low but evident risk of ceramic linear fracture, which can lead to catastrophic failure if not diagnosed and treated early.

Case presentation:

A 59-year-old male patient, who underwent a ceramic-on-ceramic THR 8 years ago, presented to our centre with a five-week history of right hip pain, after he suddenly twisted his upper body and felt a sharp pain in his groin. Prior to the injury he had an excellent functional level with the prosthesis.

His examination findings confirmed a reduced range of movement with pain in the groin on internal and external rotation. X-ray and CT of the hip confirmed a ceramic liner fracture with protrusion of the femoral head into the pelvis. A revision THR was subsequently performed.

Discussion

The usual pattern of liner fracture in this type of bearings is that the femoral head stays contained inside the metal cup. In our case, the ceramic femoral head uniquely fractured the liner and passed into the pelvis. To the best of our knowledge, this is the third reported case in literature where a ceramic femoral head protrudes through the metal cup into the pelvis.

226 Management of Liver Trauma: Outcomes at One of Europe's Most Active HPB and Liver Transplant Centres

Introduction

The management of liver trauma (LT) has gradually moved away from surgery and more towards conservative or interventional radiological management. Positive outcomes depend upon careful selection for non-operative management, and to avoid surgical intervention in all grade I-III injuries unless haemodynamically unstable following resuscitation. This study investigated the management of all LT patients over a 12-month period at our institution.

Method

We undertook a retrospective study of all patients admitted with LT in 2019 (n = 60). We assessed records to determine the grade of LT (I-VI), concurrent injuries, their management, length of stay and outcomes.

Results

Of the 60 patients admitted with LT, 43 were male (72%) and 41 patients (68%) sustained injuries to multiple organs. 53/60 patients (88%) sustained injuries classified as grade 3 or below. In patients with multiple organ injuries, 7/41 (17%) underwent intervention compared to 7/12 (58%) in those with isolated LT. No deaths were recorded in patients with LT, and 6 people died in the multiple injury group (mortality 10%). Any form of intervention was associated with a doubling in average length of stay.

Conclusions

Non-operative management underpins most isolated LT care; if this fails or is associated with multiple organ traumas, morbidity and mortality rise dramatically.

Plankton biogeography in the North Atlantic Ocean and its adjacent seas: Species assemblages and environmental signatures

Plankton biodiversity is a key component of marine pelagic ecosystems. They are at the base of the food web, control the productivity of marine ecosystems, and provide many provisioning and regulating ecological services. It is therefore important to understand how plankton are organized in both space and time. Here, we use data of varying taxonomic resolution, collected by the Continuous Plankton Recorder (CPR) survey, to map phytoplankton and zooplankton biodiversity in the North Atlantic and its adjacent seas. We then decompose biodiversity into 24 species assemblages and investigate their spatial distribution using ecological units and ecoregions recently proposed. Finally, we propose a descriptive method, which we call the environmental chromatogram, to characterize the environmental signature of each plankton assemblage. The method is based on a graphic that identifies where species of an assemblage aggregate along an environmental gradient composed of multiple ecological dimensions. The decomposition of the biodiversity into species assemblages allows us to show (a) that most marine regions of the North Atlantic are composed of coenoclines (i.e., gradients of biocoenoses or communities) and (b) that the overlapping spatial distribution of assemblages is the result of their environmental signatures. It follows that neither the ecoregions nor the ecological units identified in the North Atlantic are characterized by a unique assemblage but instead by a mosaic of assemblages that overlap in many places.

Resolving the small-pockets problem helps clarify the role of education and political ideology in shaping vaccine scepticism

Understanding the factors associated with vaccine scepticism is challenging because of the 'small-pockets' problem: The number of highly vaccine-sceptical people is low, and small subsamples such as these can be missed using traditional regression approaches. To overcome this problem, the current study (N = 5,200) used latent profile analysis to uncover six profiles, including two micro-communities of vaccine-sceptical people who have the potential to jeopardize vaccine-led herd immunity. The most vaccine-sceptical group (1.14%) was highly educated and expressed strong liberal tendencies. This group was also the most sceptical about genetically modified crops and nuclear energy, and most likely to receive news about science from the Internet. The second-most vaccine-sceptical group (3.4%) was young, poorly educated, and politically extreme (both left and right). In resolving the small-pockets problem, the current analyses also help reconcile competing theoretical perspectives about the role of education and political ideology in shaping anti-vaccination views.

Safety of tapentadol compared with other opioids in chronic pain treatment: network meta-analysis of randomized controlled and withdrawal trials

OBJECTIVE

To assess the relative safety of oral tapentadol PR and other opioid analgesics for moderate or severe chronic pain in adults, we conducted a systematic review and network meta-analysis (NMA).

METHODS

A systematic review was conducted to identify randomized controlled trials (RCTs) and randomized withdrawal trials of tapentadol with other WHO stage II and III opioid analgesics in patients with moderate or severe chronic pain. Searches were conducted in MEDLINE, EMBASE, PubMed, Cochrane databases and trial registries. Feasibility assessment evaluated the trials' suitability for NMA. Outcomes assessed were overall AEs, overall serious adverse events, constipation, nausea, dizziness, somnolence, headache, and discontinuation due to AEs. Randomized withdrawal trials were analyzed separately to other RCTs.

RESULTS

Searches conducted in April 2019 identified 16,604 records. Following screening and feasibility assessment, 29 RCTs and 19 randomized withdrawal trials were identified and included in the NMA. Consistent with existing research, evidence from RCTs suggested that tapentadol is associated with relatively lower odds of adverse events occurring than most active comparators. The withdrawal trial data were less clear, with higher uncertainty around the results, and results that appear to contradict the RCT evidence. There are a number of trial design factors that may be affecting these results.

CONCLUSIONS

RCT evidence suggests that tapentadol can be a useful treatment option for patients suffering from chronic pain and in need of an opioid analgesic. Opioids should be prescribed by a qualified physician only after other analgesics have been considered, taking side effects and misuse risk into account.

Postoperative continuous non-invasive cardiac output monitoring on the ward: a feasibility study

Postoperative hypotension is common (occurring in one third of patients) and is associated with worse clinical outcomes. The LiDCO CNAP (continuous non-invasive arterial pressure) device measures haemodynamics but has not been widely adopted in ward environments. Improved early detection of hypotension by CNAP might guide interventions to improve clinical outcomes. We aimed to find the proportion of patients who tolerated LiDCO CNAP for 12 h postoperatively, to unmask episodes of hypotension detected by continuous monitoring and to characterise the haemodynamic profile at the time of hypotension. In this feasibility study, patients undergoing major elective surgery were continuously postoperatively monitored using CNAP. Haemodynamic data gathered from CNAP, including nSVRI (nominal systemic vascular resistance index), nSVI (nominal stroke volume index), SVV (stroke volume variation) and blood pressure, were analysed using Microsoft Excel and GraphPad Prism 8. 104 patients (age (mean ± sd): 68 ± 14, male (56%)) had CNAP sited postoperatively. 39% tolerated the CNAP device for at least 12 h. Within the 104 patients a mean of 81.2 min of hypotension detected by CNAP was not detected by usual care. The proportion of low/normal/high nSVI was 71%, 27% and 2%, nSVRI was 43%, 17% and 40%, respectively. CNAP monitoring was not tolerated for 12 h in the majority of patients. There were many episodes of hypotension unmasked through continuous monitoring. Based on the advanced haemodynamic data provided it is possible that the underlying cause of a third of postoperative hypotensive episodes is vasodilation rather than hypovolaemia.Trial registry number: NCT04010058 (ClinicalTrials.gov) Date of registration: 08/07/2019.

Structures of Arabidopsis thaliana oxygen-sensing plant cysteine oxidases 4 and 5 enable targeted manipulation of their activity

In higher plants, molecular responses to exogenous hypoxia are driven by group VII ethylene response factors (ERF-VIIs). These transcriptional regulators accumulate in the nucleus under hypoxia to activate anaerobic genes but are destabilized in normoxic conditions through the action of oxygen-sensing plant cysteine oxidases (PCOs). The PCOs catalyze the reaction of oxygen with the conserved N-terminal cysteine of ERF-VIIs to form cysteine sulfinic acid, triggering degradation via the Cys/Arg branch of the N-degron pathway. The PCOs are therefore a vital component of the plant oxygen signaling system, connecting environmental stimulus with cellular and physiological response. Rational manipulation of PCO activity could regulate ERF-VII levels and improve flood tolerance, but requires detailed structural information. We report crystal structures of the constitutively expressed PCO4 and PCO5 from Arabidopsis thaliana to 1.24 and 1.91 Å resolution, respectively. The structures reveal that the PCOs comprise a cupin-like scaffold, which supports a central metal cofactor coordinated by three histidines. While this overall structure is consistent with other thiol dioxygenases, closer inspection of the active site indicates that other catalytic features are not conserved, suggesting that the PCOs may use divergent mechanisms to oxidize their substrates. Conservative substitution of two active site residues had dramatic effects on PCO4 function both in vitro and in vivo, through yeast and plant complementation assays. Collectively, our data identify key structural elements that are required for PCO activity and provide a platform for engineering crops with improved hypoxia tolerance.

Combining environmental isotopes with Contaminants of Emerging Concern (CECs) to characterise wastewater derived impacts on groundwater quality

The potential for Wastewater Treatment Plants (WWTPs) to cause adverse impacts to groundwater quality is a major global environmental challenge. Robust and sensitive techniques are required to characterise these impacts, particularly in settings with multiple potential contaminant sources (e.g. agricultural vs. site-derived). Stable (δ²H_H2O, δ¹⁸O_H2O, δ¹⁵N_NO3, δ¹⁸O_NO3 and δ¹³C_DIC) and radioactive (³H and ¹⁴C) isotopes were used in conjunction with three Contaminants of Emerging Concern (CECs) - carbamazepine, simazine and sulfamethoxazole - to discriminate between multiple potential contamination sources at an Australian WWTP. The radioactive isotope tritium provided a sensitive indicator of recent (post-1990s) leakage, with groundwater activities between 0.68 and 1.83 TU, suggesting WWTP infrastructure (activities between 1.65 and 2.41) acted as a recharge 'window', inputting treated or partially treated effluent to the underlying groundwater system. This was corroborated by water stable isotopes, which showed clear demarcation between δ¹⁸O_H2O and δ²H_H2O in background groundwater (δ¹⁸O_H2O and δ²H_H2O values of approximately -5 and -28‰, respectively) and those associated with on-site wastewater (median δ¹⁸O_H2O and δ²H_H2O values of -1.2 and -7.6‰, respectively), with groundwater down-gradient of the plant plotting on a mixing line between these values. The CECs, particularly the carbamazepine:simazine ratio, provided a means to further distinguish wastewater impacts from other sources, with groundwater down-gradient of the plant reporting elevated ratios (median of 0.98) compared to those up-gradient (median of 0.11). Distinctive CEC ratios in impacted groundwater close to the WWTP (∼3.0) and further down-gradient (2.7-9.3) are interpreted to represent a change in composition over time (i.e., recent vs. legacy contamination), consistent with the site development timeline and possible changes in effluent composition resulting from infrastructure upgrades over time. The data indicate a complex set of co-mingled plumes, reflecting different inputs (in terms of both quantity and concentration) over time. Our approach provides a means to better characterise the nature and timing of wastewater derived impacts on groundwater systems, with significant global implications for site management, potentially allowing more targeted monitoring, management and remedial actions to be undertaken.

Random telegraph signal analysis with a recurrent neural network

We use an artificial neural network to analyze asymmetric noisy random telegraph signals, and extract underlying transition rates. We demonstrate that a long short-term memory neural network can outperform other methods, particularly for noisy signals and measurements with limited bandwidths. Our technique gives reliable results as the signal-to-noise ratio approaches one, and over a wide range of underlying transition rates. We apply our method to random telegraph signals generated by quasiparticle poisoning in a superconducting double dot, allowing us to extend our measurement of quasiparticle dynamics to new temperature regimes.

Improving wellbeing among UK doctors redeployed during the COVID-19 pandemic

Background

In response to the COVID-19 pandemic, the NHS has implemented significant workforce changes to manage the increased and changing demand on healthcare services. We aimed to investigate the impact of redeployment on the wellbeing of doctors as well as highlighting ways to improve.

Methods

We conducted a survey at three NHS trusts over 2 weeks asking redeployed doctors to rate their morale, work-life balance and perceived support and safety, and to voice concerns.

Results

172 redeployed doctors responded to the survey. 66.3% felt confident in their new role, 65.7% felt satisfied or neutral with their new role and only 31.4% felt stressed at work. 66.3% felt valued by their team and 79% felt valued by the general public. 64.5% had noticed an increase in the length of breaks and 89% felt their rotas provided sufficient respite. 55.2% did not feel confident in the guidance from Public Health England/Wales on using personal protective equipment (PPE) and 54.7% did not feel safe while wearing PPE. The three most common concerns were training opportunities, PPE and family health.

Conclusion

Our findings suggest that morale is higher than might be expected with doctors feeling valued, confident and well rested in their new role. Concerns about training opportunities/career progression, PPE and family safety need to be addressed.

General Corrosion of Chromium-Coated Zirconium- and Titanium-Based Alloys in Supercritical Water at 500 °C

The 300 MWel small Canadian supercritical water-cooled reactor (SCWR), which is a scaled-down version of the original 1200 MWel concept, has a smaller core, uses low enriched uranium fuel instead of a plutonium–thorium fuel, and features a lower (maximum) cladding temperature of 500 °C. The lower cladding temperature may permit the use of different alloys, including zirconium alloys, which had been ruled out as candidates for the Canadian SCWR, whose cladding temperature may reach 850 °C. The potential to use zirconium alloys is exciting because they have a low neutron cross section, which in turn means that fewer neutrons are lost, and the fuel can be used more efficiently. One advantage, for example,, is that the fuel cycle can be lengthened. In this paper, we report on the results of corrosion experiments used to screen zirconium- and titanium-based alloys as well as corrosion-resistant coating materials such as Cr and Al as potential candidates for fuel cladding in the small Canadian SCWR. These experiments were conducted in a refreshed autoclave in deaerated supercritical water at 500 °C and 23.5 MPa. After exposure, the weight gain was measured, and the oxide thickness and the oxide phases were examined. Of all materials, the coated and uncoated Ti-grade 2 and Ti-grade 5 alloys met our screening qualification criteria, however, Al/Cr-coated zirconium coupons showed notable improvement and will be explored further in future testing.

Prognostic factors and quality of life after pelvic fractures. The Brabant Injury Outcome Surveillance (BIOS) study

Introduction

Pelvic fractures can have long-term consequences for health-related quality of life (HRQoL). The main purpose of this study is to provide insight into short-term HRQoL in the first year after pelvic injury and to identify short-term prognostic factors of decreased outcome.

Methods

This is a prospective, observational, multicenter, follow-up cohort study in which HRQoL and functional outcomes were assessed during 12-month follow-up of injured adult patients admitted to 1 of 10 hospitals in the county of Noord-Brabant, the Netherlands. The data were collected by self-reported questionnaires at 1 week (including preinjury assessment) and 1, 3, 6 and 12 months after injury. The EuroQoL-5D (EQ-5D), visual analog scale (VAS), Merle d’Aubigné Hip Score (MAHS) and Majeed Pelvic Score (MPS) were used. Multivariable mixed models were used to examine the course of the HRQoL and the prognostic factors for decreased HRQoL and functional outcomes over time.

Results

A total of 184 patients with pelvic fractures were identified between September 2015–September 2016; the fractures included 71 Tile A, 44 Tile B and 10 Tile C fractures and 59 acetabular fractures. At the pre-injury, 1 week, and 1, 3, 6 and 12 months after injury time points, the mean EQ-5D Index values were 0.90, 0.26, 0.45, 0.66, 0.77 and 0.80, respectively, and the mean EQ-VAS values were 83, 45, 57, 69, 75 and 75, respectively. At 6 and 12 months after injury, 22 and 25% of the MPS < 65 year group, 38 and 47% of the MPS ≥ 65 year group and 34 and 51% of the MAHS group, respectively, reached the maximum score. Pre-injury score, female gender and high Injury Severity Score (ISS) were important prognostic factors for a decreased HRQoL, and the EQ-5D VAS β = 0.43 (95% CI: 0.31 − 0.57), -6.66 (95% CI: -10.90 − -0.43) and -7.09 (95% CI: -6.11 − -5.67), respectively.

Discussion

Patients with pelvic fractures experience a reduction in their HRQoL. Most patients do not achieve the HRQoL of their pre-injury state within 1 year after trauma. Prognostic factors for decreased HRQoL are a low pre-injury score, high ISS and female gender. We do not recommend using the MAHS and MPS in mid- or long-term follow-up of pelvic fractures because of ceiling effects.

Trial registration number NCT02508675.

Taurine Analysis in Milk and Infant Formulae by Liquid Chromatography: Collaborative Study

A collaborative study was conducted on a liquid chromatographic (LC) method for determination of taurine in infant formula and milk powders. Twenty laboratories participated in the analysis of 8 blind duplicates over the range of approximately 3–60 mg/100 g sample. The method involved protein removal, conversion to the dansyl-derivative, and isocratic LC separation with UV and/or fluorescence detection. Following outlier treatment, overall mean RSDR has been estimated at 7.00% for sup. plemented products with a HORRAT value of 1.1. The poorer precision at endogenous levels establishes a lower limit of determination of about 5 mg/100 g. An overall mean RSDr:RSDR value of 0.7 for all products demonstrated acceptable performance.