Expert endoscopist assessment of colorectal polyp size using virtual scale endoscopy, visual or snare-based estimation: a prospective video-based study

BACKGROUND AND AIMS

Accurate polyp size estimation during colonoscopy has an impact on clinical decision-making. A laser-based virtual scale endoscope (VSE) is available to allow measuring polyp size using a virtual adaptive scale. This study evaluates video-based polyp size measurement accuracy among expert endoscopists using either VSE or visual assessment (VA) with either snare as reference size or without any reference size information.

METHODS

A prospective, video-based study was conducted with 10 expert endoscopists. Video sequences from 90 polyps with known reference size (fresh specimen measured using calipers) were distributed on three different slide sets so that each slide set showed the same polyp only once with either VSE, VA or snare-based information. A slide set was randomly assigned to each endoscopist. Endoscopists were asked to provide size estimation based on video review.

RESULTS

Relative accuracies for VSE, VA, and snare-based estimation were 75.1% (95% CI [71.6-78.5]), 65.0% (95% CI [59.5-70.4]) and 62.0% (95% CI [54.8-69.0]), respectively. VSE yielded significantly higher relative accuracy compared to VA (p = 0.002) and to snare (p = 0.001). A significantly lower percentage of polyps 1-5 mm were misclassified as >5 mm using VSE versus VA and snare (6.52% vs. 19.6% and 17.5%, p = 0.004) and a significantly lower percentage of polyps >5 mm were misclassified as 1-5 mm using VSE versus VA and snare (11.4% vs. 31.9% and 14.9%, p = 0.038).

CONCLUSIONS

Endoscopists estimate polyp size with the highest accuracy when virtual adaptive scale information is displayed. Using a snare to assist sizing did not improve measurement accuracy compared to displaying visual information alone.

Impact of Artificial Intelligence on Miss Rate of Colorectal Neoplasia

BACKGROUND & AIMS

Artificial intelligence (AI) may detect colorectal polyps that have been missed due to perceptual pitfalls. By reducing such miss rate, AI may increase the detection of colorectal neoplasia leading to a higher degree of colorectal cancer (CRC) prevention.

METHODS

Patients undergoing CRC screening or surveillance were enrolled in 8 centers (Italy, UK, US), and randomized (1:1) to undergo 2 same-day, back-to-back colonoscopies with or without AI (deep learning computer aided diagnosis endoscopy) in 2 different arms, namely AI followed by colonoscopy without AI or vice-versa. Adenoma miss rate (AMR) was calculated as the number of histologically verified lesions detected at second colonoscopy divided by the total number of lesions detected at first and second colonoscopy. Mean number of lesions detected in the second colonoscopy and proportion of false negative subjects (no lesion at first colonoscopy and at least 1 at second) were calculated. Odds ratios (ORs) and 95% confidence intervals (CIs) were adjusted by endoscopist, age, sex, and indication for colonoscopy. Adverse events were also measured.

RESULTS

A total of 230 subjects (116 AI first, 114 standard colonoscopy first) were included in the study analysis. AMR was 15.5% (38 of 246) and 32.4% (80 of 247) in the arm with AI and non-AI colonoscopy first, respectively (adjusted OR, 0.38; 95% CI, 0.23-0.62). In detail, AMR was lower for AI first for the ≤5 mm (15.9% vs 35.8%; OR, 0.34; 95% CI, 0.21-0.55) and nonpolypoid lesions (16.8% vs 45.8%; OR, 0.24; 95% CI, 0.13-0.43), and it was lower both in the proximal (18.3% vs 32.5%; OR, 0.46; 95% CI, 0.26-0.78) and distal colon (10.8% vs 32.1%; OR, 0.25; 95% CI, 0.11-0.57). Mean number of adenomas at second colonoscopy was lower in the AI-first group as compared with non-AI colonoscopy first (0.33 ± 0.63 vs 0.70 ± 0.97, P < .001). False negative rates were 6.8% (3 of 44 patients) and 29.6% (13 of 44) in the AI and non-AI first arms, respectively (OR, 0.17; 95% CI, 0.05-0.67). No difference in the rate of adverse events was found between the 2 groups.

CONCLUSIONS

AI resulted in an approximately 2-fold reduction in miss rate of colorectal neoplasia, supporting AI-benefit in reducing perceptual errors for small and subtle lesions at standard colonoscopy.

CLINICALTRIALS

gov, Number: NCT03954548.

Prenatal cannabis exposure predicts attention problems, without changes on fMRI in adolescents

OBJECTIVES

We hypothesized that prenatal cannabis exposure (PCE) would be associated with increased attention problems and altered neurocognition in young adolescents.

METHODS

Data were obtained from the Adolescent Brain Cognitive Development (ABCD study®), a cohort of approximately 12,000 children. Presence or absence of PCE after knowledge of pregnancy was measured by caregiver report. All participants with PCE (N = 224) were included and compared to two control groups; those matched on tobacco and alcohol exposure and those without prenatal tobacco or alcohol exposures. Outcomes were measured with the ABCD baseline assessment when participants were 9-10 years old and included attention, internalizing, externalizing and total problems scales on the Child Behavior Checklist (CBCL). Teacher reports were used when available. Mixed effects modeling assessed the association between PCE and outcomes controlling for parental psychopathology, prematurity and socioeconomic status. For participants with available data, patterns of brain activity during three fMRI tasks (the Stop Signal Task measuring response inhibition, the Monetary Incentive Delay (MID) task measuring reward processing and the EN-Back task measuring working memory) were analyzed using Permutation Analyses of the Linear Model.

RESULTS

Compared to both control groups, participants with PCE had significantly higher attention problems, externalizing, and total problem scores. PCE did not impact cognitive performance or patterns of brain activation during fMRI tasks.

CONCLUSIONS

There are long-term associations between PCE and early adolescent attention and behavioral problems. These are not reflected in cognitive performance or task fMRI measures, a finding that is consistent with reports that fewer than half of children with ADHD have any specific cognitive deficit (Nigg et al., 2005; Willcutt et al., 2005). The young age of the sample may also relate to this finding and future investigation of neurodevelopmental trajectories of youth with PCE is warranted.

Air quality modeling to inform pollution mitigation strategies in a Latin American megacity

Poor air quality disproportionally impacts cities in low- and middle-income countries. In Bogotá, Colombia, a metropolitan area with over 10 million inhabitants, fine particulate matter (PM_2.5) levels regularly exceed air quality guidelines, leading to detrimental effects on health. Although there is public interest to improve the city's air quality, the main sources of PM_2.5 pollution have not been clearly identified and the use of modeling for policy development in Bogotá has been limited. Here, we apply a modeling framework based on the Community Multiscale Air Quality Modeling System (CMAQ) to conduct seasonal simulations of air pollution in Bogotá and reveal the emissions sectors with the largest contributions to PM_2.5. Based on these results, we project and compare the air quality benefits of potential pollution mitigation strategies focused on these sources. The analysis finds that resuspended dust from unpaved roads is the largest local source of PM_2.5 and can contribute over 30% of seasonally-averaged concentration across the city. Vehicles, industrial activity, and unpaved road dust combined are responsible for over 60% of PM_2.5 pollution in Bogotá. A scenario analysis shows that paving roads can lead to PM_2.5 decreases of nearly 10 μg/m³ by 2030 in some areas of the city, but air quality will deteriorate significantly over others in the absence of additional emissions control measures. Mitigation strategies designed to target the sectors with the largest contributions to PM_2.5, including road cleaning systems, controls for industrial point sources, cleaner transportation fuels, and updated vehicle fleets, can largely avert projected increases in concentrations, although the impacts of different approaches vary throughout the city. This study is the first to use a comprehensive model to determine sector contributions to air pollution and inform potential emissions control policies in Bogotá, demonstrating an approach to guide pollution management in developing cities facing comparable challenges.

Mitochondrial ATP fuels ABC transporter-mediated drug efflux in cancer chemoresistance

Chemotherapy remains the standard of care for most cancers worldwide, however development of chemoresistance due to the presence of the drug-effluxing ATP binding cassette (ABC) transporters remains a significant problem. The development of safe and effective means to overcome chemoresistance is critical for achieving durable remissions in many cancer patients. We have investigated the energetic demands of ABC transporters in the context of the metabolic adaptations of chemoresistant cancer cells. Here we show that ABC transporters use mitochondrial-derived ATP as a source of energy to efflux drugs out of cancer cells. We further demonstrate that the loss of methylation-controlled J protein (MCJ) (also named DnaJC15), an endogenous negative regulator of mitochondrial respiration, in chemoresistant cancer cells boosts their ability to produce ATP from mitochondria and fuel ABC transporters. We have developed MCJ mimetics that can attenuate mitochondrial respiration and safely overcome chemoresistance in vitro and in vivo. Administration of MCJ mimetics in combination with standard chemotherapeutic drugs could therefore become an alternative strategy for treatment of multiple cancers.

333 Management of Distal Radius Fractures During The COVID-19 Crisis

Introduction

Distal radius fractures are common. Treatment depends on a multitude of factors including the pattern / displacement of the fracture, patient age, pre-morbid function, and surgeon preference. We aim to investigate the effect of the pandemic on the management and short-term outcomes of patients with DRF’s.

Method

Retrospective review of all adult DRF’s two months before and after BOA released emergency standards on trauma management. The primary outcome measure was the proportion of patients managed non-operatively before and during COVID-19. Data extracted: demographics, comorbidities, cognitive baseline, treatment, and follow-up. Radiographs were reviewed for displacement [dorsal tilt (>10^o), ulnar variance (>3mm), intra-articular step (>2mm)].

Results

Pre-COVID (n = 29), COVID (n = 35). Characteristics were comparable in terms of median age (66 and 72 years, p = 0.41), %aged ≤65 (48% and 37%, p = 0.37), dominant side fracture (36% and 40%, p = 0.52), presence ≥ 2 co-morbidities (41% and 43%, p = 0.91). More patients were managed non-operatively during COVID (86% vs. 69%, p = 0.11), 2 of whom had unstable fracture pattern and developed malunion, compared to none in pre-COVID period.

Conclusions

Management of DRF’s remains a controversial topic, particularly in age <65 years. Long term follow up of patients with significant fracture displacement managed conservatively during COVID pandemic could help guide future practice.

Efficacy and Tolerability of High- vs Low-Volume Split-Dose Bowel Cleansing Regimens for Colonoscopy: A Systematic Review and Meta-analysis

BACKGROUND & AIMS

Efficacy of bowel preparation is an important determinant of outcomes of colonoscopy. It is not clear whether approved low-volume polyethylene glycol (PEG) and non-PEG regimens are as effective as high-volume PEG regimens when taken in a split dose.

METHODS

In a systematic review of multiple electronic databases through January 31, 2019 with a registered protocol (PROSPERO: CRD42019128067), we identified randomized controlled trials that compared low- vs high-volume bowel cleansing regimens, administered in a split dose, for colonoscopy. The primary efficacy outcome was rate of adequate bowel cleansing, and the secondary efficacy outcome was adenoma detection rate. Primary tolerability outcomes were compliance, tolerability, and willingness to repeat. We calculated relative risk (RR) and 95% CI values and assessed heterogeneity among studies by using the I² statistic. The overall quality of evidence was assessed using the GRADE framework.

RESULTS

In an analysis of data from 17 randomized controlled trials, comprising 7528 patients, we found no significant differences in adequacy of bowel cleansing between the low- vs high-volume split-dose regimens (86.1% vs 87.4%; RR, 1.00; 95% CI, 0.98-1.02) and there was minimal heterogeneity (I² = 17%). There was no significant difference in adenoma detection rate (RR, 0.96; 95% CI, 0.87-1.08) among 4 randomized controlled trials. Compared with high-volume, split-dose regimens, low-volume split-dose regimens had higher odds for compliance or completion (RR, 1.06; 95% CI, 1.02-1.10), tolerability (RR, 1.39; 95% CI, 1.12-1.74), and willingness to repeat bowel preparation (RR, 1.41; 95% CI, 1.20-1.66). The overall quality of evidence was moderate.

CONCLUSIONS

Based on a systematic review of 17 randomized controlled trials, low-volume, split-dose regimens appear to be as effective as high-volume, split-dose regimens in bowel cleansing and are better tolerated, with superior compliance.

British Society of Gastroenterology/Association of Coloproctology of Great Britain and Ireland/Public Health England post-polypectomy and post-colorectal cancer resection surveillance guidelines

These consensus guidelines were jointly commissioned by the British Society of Gastroenterology (BSG), the Association of Coloproctology of Great Britain and Ireland (ACPGBI) and Public Health England (PHE). They provide an evidence-based framework for the use of surveillance colonoscopy and non-colonoscopic colorectal imaging in people aged 18 years and over. They are the first guidelines that take into account the introduction of national bowel cancer screening. For the first time, they also incorporate surveillance of patients following resection of either adenomatous or serrated polyps and also post-colorectal cancer resection. They are primarily aimed at healthcare professionals, and aim to address:Which patients should commence surveillance post-polypectomy and post-cancer resection?What is the appropriate surveillance interval?When can surveillance be stopped? two or more premalignant polyps including at least one advanced colorectal polyp (defined as a serrated polyp of at least 10 mm in size or containing any grade of dysplasia, or an adenoma of at least 10 mm in size or containing high-grade dysplasia); or five or more premalignant polyps The Appraisal of Guidelines for Research and Evaluation (AGREE II) instrument provided a methodological framework for the guidelines. The BSG's guideline development process was used, which is National Institute for Health and Care Excellence (NICE) compliant.two or more premalignant polyps including at least one advanced colorectal polyp (defined as a serrated polyp of at least 10 mm in size or containing any grade of dysplasia, or an adenoma of at least 10 mm in size or containing high-grade dysplasia); or five or more premalignant polyps The key recommendations are that the high-risk criteria for future colorectal cancer (CRC) following polypectomy comprise either:two or more premalignant polyps including at least one advanced colorectal polyp (defined as a serrated polyp of at least 10 mm in size or containing any grade of dysplasia, or an adenoma of at least 10 mm in size or containing high-grade dysplasia); or five or more premalignant polyps This cohort should undergo a one-off surveillance colonoscopy at 3 years. Post-CRC resection patients should undergo a 1 year clearance colonoscopy, then a surveillance colonoscopy after 3 more years.

Bowel preparation for colonoscopy: European Society of Gastrointestinal Endoscopy (ESGE) Guideline - Update 2019

ESGE recommends a low fiber diet on the day preceding colonoscopy.Strong recommendation, moderate quality evidence.ESGE recommends the use of enhanced instructions for bowel preparation.Strong recommendation, moderate quality evidence.ESGE suggests adding oral simethicone to bowel preparation.Weak recommendation, moderate quality evidence.ESGE recommends split-dose bowel preparation for elective colonoscopy.Strong recommendation, high quality evidence.ESGE recommends, for patients undergoing afternoon colonoscopy, a same-day bowel preparation as an acceptable alternative to split dosing.Strong recommendation, high quality evidence.ESGE recommends to start the last dose of bowel preparation within 5 hours of colonoscopy, and to complete it at least 2 hours before the beginning of the procedure.Strong recommendation, moderate quality evidence.ESGE recommends the use of high volume or low volume PEG-based regimens as well as that of non-PEG-based agents that have been clinically validated for routine bowel preparation. In patients at risk for hydroelectrolyte disturbances, the choice of laxative should be individualized.Strong recommendation, moderate quality evidence.

Association analyses identify 31 new risk loci for colorectal cancer susceptibility

Colorectal cancer (CRC) is a leading cause of cancer-related death worldwide, and has a strong heritable basis. We report a genome-wide association analysis of 34,627 CRC cases and 71,379 controls of European ancestry that identifies SNPs at 31 new CRC risk loci. We also identify eight independent risk SNPs at the new and previously reported European CRC loci, and a further nine CRC SNPs at loci previously only identified in Asian populations. We use in situ promoter capture Hi-C (CHi-C), gene expression, and in silico annotation methods to identify likely target genes of CRC SNPs. Whilst these new SNP associations implicate target genes that are enriched for known CRC pathways such as Wnt and BMP, they also highlight novel pathways with no prior links to colorectal tumourigenesis. These findings provide further insight into CRC susceptibility and enhance the prospects of applying genetic risk scores to personalised screening and prevention.

Telomere length and genetics are independent colorectal tumour risk factors in an evaluation of biomarkers in normal bowel

BACKGROUND

Colorectal cancer (CRC) screening might be improved by using a measure of prior risk to modulate screening intensity or the faecal immunochemical test threshold. Intermediate molecular biomarkers could aid risk prediction by capturing both known and unknown risk factors.

METHODS

We sampled normal bowel mucosa from the proximal colon, distal colon and rectum of 317 individuals undergoing colonoscopy. We defined cases as having a personal history of colorectal polyp(s)/cancer, and controls as having no history of colorectal neoplasia. Molecular analyses were performed for: telomere length (TL); global methylation; and the expression of genes in molecular pathways associated with colorectal tumourigenesis. We also calculated a polygenic risk score (PRS) based on CRC susceptibility polymorphisms.

RESULTS

Bowel TL was significantly longer in cases than controls, but was not associated with blood TL. PRS was significantly and independently higher in cases. Hypermethylation showed a suggestive association with case:control status. No gene or pathway was differentially expressed between cases and controls. Gene expression often varied considerably between bowel locations.

CONCLUSIONS

PRS and bowel TL (but not blood TL) may be clinically-useful predictors of CRC risk. Sample collection to assess these biomarkers is feasible in clinical practice, especially where population screening uses flexible sigmoidoscopy or colonoscopy.

Nutritional pathway for people with motor neurone disease

This paper provides an overview of the nutritional management and care of people living with motor neurone disease (MND) in a specialist nutrition clinic. A specialist pathway of care has been developed to enable people living with MND to undergo a percutaneous endoscopic gastrostomy (PEG) procedure in a safe way; the pathway incorporates attendance at a dedicated nutrition clinic, a stratification tool to identify patients with a high periprocedural risk and a PEG insertion team with significant experience in the MND population. Since this pathway has been in place, gastrostomies have been successfully placed in patients with a forced vital capacity (FVC) of less than 50%; previously, this would not have been possible.

Screening for Lynch syndrome and referral to clinical genetics by selective mismatch repair protein immunohistochemistry testing: an audit and cost analysis

Lynch syndrome (LS) accounts for around 3% of colorectal cancers (CRCs) and is caused by germline mutations in mismatch repair (MMR) genes. Recently, screening strategies to identify patients with LS have become popular. We audited CRCs screened with MMR immunohistochemistry (IHC) in 2013. 209 tumours had MMR IHC performed at a cost of £12 540. 47/209 (21%) cases showed IHC loss of expression in at least one MMR protein. 28/44 cases with loss of MLH1 had additional BRAF V600E testing, at a cost of £5040. MMR IHC reduced the number of potential clinical genetics referrals from 209 to 47. BRAF mutation testing, performed in a subset of cases with MLH1 loss, further reduced this to 21. At a cost of £1340 per referral, this model of LS screening for clinical genetics referral had significant potential savings (£234 340) and can be easily implemented in parallel with MMR IHC done for prognostication in CRCs.

Clinical significance of the muscle-retracting sign during colorectal endoscopic submucosal dissection

BACKGROUND AND STUDY AIMS

During colorectal endoscopic submucosal dissection (ESD), the feature of a muscle layer being pulled toward a neoplastic tumor is sometimes detected. We call this feature the muscle-retracting sign (MR sign). The aim of this study was to evaluate whether the MR sign is associated with particular types of neoplastic lesions and whether it has any clinical significance for ESD sessions.

PATIENTS AND METHODS

A total of 329 patients underwent ESD for 357 colorectal neoplasms. The frequency of positivity for the MR sign was evaluated in different morphologic and histopathologic types of neoplasm. The success rate of complete resection and the incidence of complications were also evaluated according to whether lesions were positive or negative for the MR sign.

RESULTS

The rates of positivity for the MR sign in the various lesion types were as follows: laterally spreading tumor - granular nodular mixed type (LST-G-M), 9.6 %; laterally spreading tumor - granular homogeneous type (LST-G-H) and laterally spreading tumor - nongranular type (LST-NG), 0 %; sessile type, 41.2 %. The resection rate was 100 % (329 /329) in lesions negative for the MR sign; however, it was 64.3 % (18 /28) in lesions positive for the MR sign, which was significantly lower (P < 0.001).

CONCLUSIONS

The MR sign was present only in some protruding lesions, and more importantly, it was associated with a high risk of incomplete tumor removal by ESD. Our data indicate that lesions positive for the MR sign lesions should be dissected with great caution; alternatively, based on the features of the individual case, a switch to surgery should be considered for the benefit of the patient.

Generation of functional natural killer T cell subsets from human bone marrow derived adult hematopoietic stem progenitor cells (P4456)

Natural killer T (NKT) cells constitute an important subset of T cells that can both directly and indirectly mediate anti-tumor immunity. However, cancer patients have a reduction in both NKT cell number and function, and these deficits limit the potential clinical application of NKT cells for cancer therapy. To overcome the problem of limited NKT cell numbers, we have investigated whether NKT cells can be generated in vitro from bone marrow-derived adult hematopoietic stem-progenitor cells (HSPC).Our data demonstrate that co-culture of human bone marrow HSPC with OP9 stromal cells transduced with Notch ligand delta-like 1 (OP9-DL1), generates a CD3+ T cell population. These CD3+ precursors can be further differentiated into CD8- NKT cells by secondary culture with CD1d-Ig based artificial antigen presenting cells (aAPC), expressing anti-CD28mAb and loaded with α-GalCer. Importantly, these in vitro-generated NKT cells are functional as demonstrated by their ability to proliferate and secrete IFN-γ following stimulation. These findings demonstrated for the first time that functional human NKT cells can be effectively generated from HSPC in the absence of genetic manipulation or viral transduction. These studies will serve to help understand and design NKT cell-based approaches to enhance current immunotherapeutic strategies for cancer.

A basal gradient of Wnt and stem-cell number influences regional tumour distribution in human and mouse intestinal tracts

OBJECTIVE

Wnt signalling is critical for normal intestinal development and homeostasis. Wnt dysregulation occurs in almost all human and murine intestinal tumours and an optimal but not excessive level of Wnt activation is considered favourable for tumourigenesis. The authors assessed effects of pan-intestinal Wnt activation on tissue homeostasis, taking into account underlying physiological Wnt activity and stem-cell number in each region of the bowel.

DESIGN

The authors generated mice that expressed temporally controlled, stabilised β-catenin along the crypt-villus axis throughout the intestines. Physiological Wnt target gene activity was assessed in different regions of normal mouse and human tissue. Human intestinal tumour mutation spectra were analysed.

RESULTS

In the mouse, β-catenin stabilisation resulted in a graduated neoplastic response, ranging from dysplastic transformation of the entire epithelium in the proximal small bowel to slightly enlarged crypts of non-dysplastic morphology in the colorectum. In contrast, stem and proliferating cell numbers were increased in all intestinal regions. In the normal mouse and human intestines, stem-cell and Wnt gradients were non-identical, but higher in the small bowel than large bowel in both species. There was also variation in the expression of some Wnt modulators. Human tumour analysis confirmed that different APC mutation spectra are selected in different regions of the bowel.

CONCLUSIONS

There are variable gradients in stem-cell number, physiological Wnt activity and response to pathologically increased Wnt signalling along the crypt-villus axis and throughout the length of the intestinal tract. The authors propose that this variation influences regional mutation spectra, tumour susceptibility and lesion distribution in mice and humans.

Retrograde-viewing device improves adenoma detection rate in colonoscopies for surveillance and diagnostic workup

AIM: To determine which patients might benefit most from retrograde viewing during colonoscopy through subset analysis of randomized, controlled trial data.

METHODS: The Third Eye^® Retroscope^® Randomized Clinical Evaluation (TERRACE) was a randomized, controlled, multicenter trial designed to evaluate the efficacy of a retrograde-viewing auxiliary imaging device that is used during colonoscopy to provide a second video image which allows viewing of areas on the proximal aspect of haustral folds and flexures that are difficult to see with the colonoscope’s forward view. We performed a post-hoc analysis of the TERRACE data to determine whether certain subsets of the patient population would gain more benefit than others from use of the device. Subjects were patients scheduled for colonoscopy for screening, surveillance or diagnostic workup, and each underwent same-day tandem examinations with standard colonoscopy (SC) and Third Eye colonoscopy (TEC), randomized to SC followed by TEC or vice versa.

RESULTS: Indication for colonoscopy was screening in 176/345 subjects (51.0%), surveillance after previous polypectomy in 87 (25.2%) and diagnostic workup in 82 (23.8%). In 4 subjects no indication was specified. Previously reported overall results had shown a net additional adenoma detection rate (ADR) with TEC of 23.2% compared to SC. Relative risk (RR) of missing adenomas with SC vs TEC as the initial procedure was 1.92 (P = 0.029). Post-hoc subset analysis shows additional ADRs for TEC compared to SC were 4.4% for screening, 35.7% for surveillance, 55.4% for diagnostic and 40.7% for surveillance and diagnostic combined. The RR of missing adenomas with SC vs TEC was 1.11 (P = 0.815) for screening, 3.15 (P = 0.014) for surveillance, 8.64 (P = 0.039) for diagnostic and 3.34 (P = 0.003) for surveillance and diagnostic combined. Although a multivariate Poisson regression suggested gender as a possibly significant factor, subset analysis showed that the difference between genders was not statistically significant. Age, bowel prep quality and withdrawal time did not significantly affect the RR of missing adenomas with SC vs TEC. Mean sizes of adenomas detected with TEC and SC were similar at 0.59 cm and 0.56 cm, respectively (P = NS).

CONCLUSION: TEC allows detection of significantly more adenomas compared to SC in patients undergoing surveillance or diagnostic workup, but not in screening patients (ClinicalTrials.gov Identifier: NCT01044732).

Hereditary mixed polyposis syndrome is caused by a 40-kb upstream duplication that leads to increased and ectopic expression of the BMP antagonist GREM1

The hereditary mixed polyposis syndrome (HMPS) was first described about 50 years ago in a large Ashkenazi Jewish family from St Mark’s Hospital, London. The family showed apparent autosomal dominant inheritance of multiple types of colorectal polyp, with colorectal carcinoma in a high proportion of individuals. In the last 15 years, we have mapped the HMPS gene to chromosome 15q13.3 and identified an ancestral haplotype common to all the known HMPS families. Here, we have used genetic mapping, copy number analysis, exclusion of mutations by high-throughput sequencing, gene expression analysis and functional assays to show that HMPS is caused by a large duplication spanning the 3′ end of the SCG5 gene and a region upstream of the GREM1 locus. This mutation has no effect on SCG5 expression, but is associated with greatly increased, allele-specific GREM1 expression. Whilst GREM1 is expressed in intestinal sub-epithelial myofibroblasts in controls, HMPS patients predominantly express GREM1 in the epithelium of the large bowel. The HMPS duplication contains predicted transcriptional enhancer elements; we have shown that some of these interact with the GREM1 promoter and are capable of driving gene expression in vitro. Increased GREM1 expression is predicted to lead to reduced bone morphogenetic protein pathway activity, a mechanism that also underlies tumorigenesis in juvenile polyposis of the large bowel. The pathogenic mechanism in HMPS is extremely unusual in Mendelian cancer syndromes and highlights ectopic gene expression as a mechanism of tumorigenesis.

Increase in natural killer T (NKT) Cell activation in hypoxic environments via the induction of HIF1alpha (162.16)

Tumors often experience hypoxic microenvironments due to poor vascular access in the early stage of neoplastic growth and continue to experience oxygen deficits in late stage progression despite the increase in neovascularization to the primary tumor or metastasis. This persistent hypoxic state selects for tumors cells that are able to compensate for low oxygen levels by increasing use of the glycolytic cycle under aerobic conditions (The Warburg Effect), suppressing apoptosis and inducing decreased genomic stability. These effects have been shown to be mediated, at least in part, by the transcription factor hypoxia inducible factor (HIF)-1alpha. Natural Killer T (NKT) cells are a subset of T cells that recognize a wide range of lipid antigens presented by the MHC Class I-like CD1d molecule. In this study, we sought to investigate the effects of hypoxia induction on CD1d-mediated NKT cell responses. Pharmacological agents were used to induce HIF-1a in LCD1d, and then we assessed their ability to present endogenous antigen to NKT cells. It was found that the induction of HIF-1a resulted in a significant increase in CD1d-mediated NKT cell activation, as assessed by IL-2, GM-CSF, and IL-13 production. The increase in NKT function was not due to with an increase in cell surface expression of CD1d. These results suggest that hypoxia in tumor cells may alter the repertoire of endogenous lipids presented in the context of CD1d which permits their recognition by NKT cells.

Results of an exercise to estimate the costs of interpersonal violence in Jamaica

This report describes the application of a draft version of the World Health Organization (WHO)/ United States Centers for Disease Control and Prevention (CDC) Manual for estimating the economic costs of injuries due to interpersonal and self-directed violence to measure costs of injuries from interpersonal violence.

METHODS

Fatal incidence data was obtained from the Jamaica Constabulary Force. The incidence of nonfatal violence-related injuries that required hospitalization was estimated using data obtained from patients treated at and/or admitted to three Type A government hospitals in 2006.

RESULTS

During 2006, direct medical cost (J$2.1 billion) of injuries due to interpersonal violence accounted for about 12% of Jamaica's total health budget while productivity losses due to violence-related injuries accounted for approximately J$27.5 billion or 160% of Jamaica's total health expenditure and 4% of Jamaica's Gross Domestic Product.

CONCLUSIONS

The availability of accurate and reliable data of the highest quality from health-related information systems is critical for providing useful data on the burden of violence and injury to decision-makers. As Ministries of Health take a leading role in violence and injury prevention, data collection and information systems must have a central role. This study describes the results of one approach to examining the economic burden of interpersonal violence in developing countries where the burden of violence is heaviest. The WHO-CDC manual also tested in Thailand and Brazil is a first step towards generating a reference point for resource allocation, priority setting and prevention advocacy.

Effect of visualization display colour on polyp conspicuity at virtual colonoscopy

AIM

To investigate the effect of different colour three-dimensional (3D) displays on polyp detection at virtual colonoscopy (VC).

METHODS

Five VC trained observers were shown "brief flashes" (lasting 0.2s) of 125 3D endoluminal image snap-shots, repeated for each of six display colours (750 images total). One hundred images contained a single polyp (diameter range 5-42 mm) and 25 contained no polyp ("normal"). Images were reviewed in random order over five reading sessions, readers recording either normality or presence and location of a polyp. Multilevel logistic regression was used to examine any influence of colour on polyp detection stratified according to polyp size (medium 5-9 mm/large >or=10mm). The kappa statistic was used to assess effect of colour on observer agreement.

RESULTS

Individual reader polyp detection rates ranged between 75-94%. Compared to the default pink "soft tissue" display, the odds of polyp detection were 0.65 (CI 0.41,1.01) for green, 0.82 (0.53,1.30) for blue, 1 (0.63,1.59) for red, 1.12 (0.7,1.79) for monochrome, and 1.15 for yellow (0.72,1.84). Overall, there was no significant difference between the displays (p=0.11). Including normal cases, there was no overall difference in correct case classification between the six colours (p=0.44). The odds of detecting large versus medium polyps was significantly greater for 3/5 observers; odds ratio (OR) 2.84-10.1, although unaffected by display colour (p=0.3).

CONCLUSION

The background colour display generally has a minimal effect on polyp detection at VC, although green should be avoided.

Subxiphoid pericardial window in stable cardiac proximity injuries

The use of the subxiphoid pericardial window (SPW) in evaluating stable patients with cardiac proximity injuries is presented in a short case series. There were 11 patients with four positive and seven negative SPW. There was one false positive and no false negatives. Review of the literature on the use of the SPW as a diagnostic tool in evaluating cardiac proximity injuries shows the SPW to be a rapid and reliable method of detecting occult cardiac injuries, and is especially useful in areas where emergency echocardiography is not available.

Pica during pregnancy in low-income women born in Mexico

OBJECTIVE

To describe pica behavior (ingestion of nonfood items) in pregnant low-income Mexican-born women in Mexico and the United States.

DESIGN

A convenience sample of informants was interviewed with a questionnaire containing open-ended and closed-ended questions.

SETTING

A low-income community on the outskirts of Ensenada, Mexico, and clinics serving low-income people in southern California (Santa Ana, Bakersfield, and Los Angeles).

PARTICIPANTS

Of a total of 225 Mexican-born women, 75 (33%) were interviewed in Ensenada, and 150 (67%) were interviewed in southern California.

RESULTS

The prevalence of pica during pregnancy was 44% (n = 33) in the Ensenada group and 31% (n = 46) in the southern California group. Those who reported pica behavior more commonly had a relative who also practiced pica.

CONCLUSION

The high reported rate of pica in this sample indicates that pregnant Mexican-born women should be screened for pica and educated about the potentially serious effects on the fetus and mother.

Control of infection in nursing homes: a risk-management approach

The concept of risk addresses the probability that an untoward incident will occur. In the healthcare setting, professionals have a responsibility to identify risks over which they have some control and to take appropriate measures to minimise those risks. This process is referred to as risk management when actively undertaken. During our work with clinical and non-clinical staff in nursing homes, it became increasingly clear that old ritualistic habits remained and compromised effective infection control practice. To try to develop a more effective management of the risks associated with this environment, we worked with a number of homes to enable them to develop and implement a modified risk-management process in relation to infection control practice. The staff carried out a brief risk review, including assessment of: (a) Possible risk exposures; (b) Appropriate methods of control; (c) Selecting and implementing the best method of control; (d) Evaluating and monitoring improvements in risk reduction and patient outcomes. Tools were devised and utilised in three main areas: (1) Risks to the patient; (2) Risks to the staff; (3) Environmental risks and controls. These interventions are currently being evaluated. As there is little baseline data in this type of care environment, evaluation of the impact of these interventions will take some time to assess.

Aneurysm of the gluteal artery

One case of atherosclerotic gluteal artery aneurysm (GAA) is presented. The diagnosis was made preoperatively, and treatment involved ligation and division of the internal iliac artery only. This therapeutic option is discussed as the preferred one compared to the conventional two-step procedure.

Egg hatching activity of trihydroxylated eicosanoids in the barnacle Balanus balanoides

Previous work has shown that eicosanoid hatching factors can be isolated from tissues of a variety of barnacle species. To further investigate the nature of barnacle hatching factor an eicosanoid fraction isolated from homogenates of the barnacle Balanus balanoides was purified on RP-HPLC and trihydroxy fatty acid fractions were bioassayed for hatching activity and analysed by GC-MS. The identified eicosanoids were 8,11,12-trihydroxy-5,9,14-eicosatrienoic acid, 8,11,12-trihydroxy-5,9,14,17-eicosatetraenoic acid, 10,11,12-trihydroxy-5,8,14,17-eicosatetraenoic acid and 10,13, 14-trihydroxy-4,7,11,16,19-docosapentaenoic acid. These studies suggest that barnacles possess a potent n-9 lipoxygenase which can metabolise either arachidonic acid, eicosapentaenoic acid or docosahexaenoic acid. The predominant eicosanoids common to all active fractions were either 8,11,12-trihydroxyeicosatrienoic acid or an isomer of 8,11-12-trihydroxyeicosatetraenoic acid, which suggests that a particular configuration of an 8,11,12 triol is barnacle hatching factor.

An outbreak of pemphigus neonatorum

During the summer of 1987, an epidemic of pemphigus neonatorum took place at Guy's Hospital. It involved more than 80 neonates in the maternity unit. Swabs from the umbilical stumps of the babies and from the noses of several attending midwives yielded Staphylococcus aureus of phage-type Group II 3A/3C. Despite an extensive disinfection policy, which included identification and treatment of carriers, the outbreak persisted for 3 months. Final resolution came only after detailed epidemiological research revealed those midwives most likely to be involved. After these had been singled out for further treatment, the outbreak ended. The epidemic strains were later subjected to reverse phage-typing, plasmid profiling and in vivo testing for production of epidermolytic toxin in order to confirm true carriers and cases. Retrospective analysis identified those persons most likely to have been responsible for propagation of the epidemic strain. The exact course of the outbreak was then clarified.