Patient safety incidents in endoscopy: a human factors analysis of nonprocedural significant harm incidents from the National Reporting and Learning System (NRLS)

BACKGROUND

Despite advances in understanding and reducing the risk of endoscopic procedures, there is little consideration of the safety of the wider endoscopy service. Patient safety incidents (PSIs) still occur. We sought to identify nonprocedural PSIs (nPSIs) and their causative factors from a human factors perspective and generate ideas for safety improvement.

METHODS

Endoscopy-specific PSI reports were extracted from the National Reporting and Learning System (NRLS). A retrospective, cross-sectional human factors analysis of data was performed. Two independent researchers coded data using a hybrid thematic analysis approach. The Human Factors Analysis and Classification System (HFACS) was used to code contributory factors. Analysis informed creation of driver diagrams and key recommendations for safety improvement in endoscopy.

RESULTS

From 2017 to 2019, 1181 endoscopy-specific PSIs of significant harm were reported across England and Wales, with 539 (45.6%) being nPSIs. Five categories accounted for over 80% of all incidents, with "follow-up and surveillance" being the largest (23.4% of all nPSIs). From the free-text incident reports, 487 human factors codes were identified. Decision-based errors were the most common act prior to PSI occurrence. Other frequent preconditions to incidents were focused on environmental factors, particularly overwhelmed resources, patient factors, and ineffective team communication. Lack of staffing, standard operating procedures, effective systems, and clinical pathways were also contributory. Seven key recommendations for improving safety have been made in response to our findings.

CONCLUSIONS

This was the first national-level human factors analysis of endoscopy-specific PSIs. This work will inform safety improvement strategies and should empower individual services to review their approach to safety.

Development, validation, and results of a national endoscopy safety attitudes questionnaire (Endo-SAQ)

Background and study aims Safety attitudes are linked to patient outcomes. The Joint Advisory Group on Gastrointestinal Endoscopy (JAG) identifies the need to improve our understanding of safety culture in endoscopy. We describe the development and validation of the Endo-SAQ (endoscopy safety attitudes questionnaire) and the results of a national survey of staff attitudes. Methods Questions from the original SAQ were adapted to reflect endoscopy-specific content. This was refined by an expert group, followed by a pilot study to assess acceptability. The refined Endo-SAQ (comprising 35 questions across six domains) was disseminated to endoscopy staff across the UK and Ireland. Outcomes were domain scores and the percentage of positive responses (score ≥75/100) per domain. Descriptive and comparative analyses were performed. Binary logistic regression identified staff and service factors associated with positive scores. Validity and reliability of Endo-SAQ were assessed through psychometric analysis. Results After expert review, four questions in the preliminary Endo-SAQ were adjusted. Sixty-one participants undertook the pilot study with good acceptability. A total of 453 participants completed the refined Endo-SAQ. There were positive responses in teamwork, safety climate, job satisfaction, and working conditions domains. Endoscopists had significantly more positive responses to stress recognition and working conditions than nursing staff. JAG accreditation was associated with positive scores in safety climate and job satisfaction domains. Endo-SAQ met thresholds of construct validity and reliability. Conclusions Endoscopy staff had largely positive safety attitudes scores but there were significant differences across domains and staff. There is evidence for the validity and reliability of Endo-SAQ. Endo-SAQ could complement current measures of patient safety in endoscopy and be used in evaluation and research.

Development of the "Teamwork in Endoscopy Assessment Module for Endoscopic Non-Technical Skills" (TEAM-ENTS) behavioral marker system

BACKGROUND

Non-technical skills (NTS) are integral to team performance and subsequent quality and safety of care. Behavioral marker systems (BMSs) are now increasingly used in healthcare to support the training and assessment of team NTS. Within gastrointestinal endoscopy, this is an area of novel research. The aims of this study were to define the core relevant NTS for endoscopy teams and develop a preliminary framework for a team-based BMS known as TEAM-ENTS (Teamwork in Endoscopy Assessment Module for Endoscopic Non-Technical Skills).

METHODS

This study was conducted in two phases. In phase 1, a literature review of team-based BMSs was performed to inform an interview study of core endoscopy team members. Cognitive task analysis was used to break down the NTS relevant to endoscopy teams. Framework analysis generated the structure for the preliminary TEAM-ENTS framework. In phase 2, a modified Delphi process was undertaken to refine the items of the framework.

RESULTS

Seven consultant endoscopists and six nurses were interviewed. The final coding framework consisted of 88 codes grouped into five overarching categories. In total, 58 participants were recruited to the Delphi panel. In the first round, nine elements and 37 behavioral descriptors did not meet consensus. Following item adjustment, merging and deletion, all remaining items met consensus thresholds after the second round. The refined TEAM-ENTS BMS consists of five categories, 16 elements, and 47 behavioral descriptors.

CONCLUSIONS

The refined TEAM-ENTS behavioral marker system was developed to reflect the core NTS relevant to endoscopy teams. Future studies will aim to fully validate this tool.

Duodenal eosinophilia is associated with symptomatic erosive gastro-oesophageal reflux disease, presence of co-morbidities, and ethnicity but not undifferentiated functional dyspepsia: A retrospective Malaysian study

BACKGROUND

Duodenal eosinophilia is postulated to play a key role in the pathogenesis of functional dyspepsia, a common condition responsible for considerable impairment of quality of life. Our objective was to evaluate the relative strength of the associations between duodenal eosinophilia, functional dyspepsia, symptomatic erosive gastroesophageal reflux disease (GERD), the presence of co-morbidities, and a number of other variables.

METHODS

Eosinophil counts of archived endoscopic duodenal biopsies of 289 subjects were determined by a pathologist blinded to the clinical data. Duodenal eosinophilia was defined by a count of more than 15 per 5 high power fields. Clinical charts were reviewed by a gastroenterologist blinded to the histology review.

RESULTS

In the study sample, the primary diagnosis was functional dyspepsia (undifferentiated by subtypes) in 45, symptomatic erosive GERD in 29, gall stone disease in 17, irritable bowel syndrome in 23, and an alternative or undetermined diagnosis in 175 subjects, respectively. On logistic regression analyses, eosinophil counts were positively associated with symptomatic erosive GERD (Odds Ratio, OR 1.03, 95% Confidence Interval, 95%CI: 1.00, 1.05; p=0.035) but not functional dyspepsia. Pre-defined duodenal eosinophilia was associated with symptomatic erosive gastro-oesophageal reflux disease (OR 3.36, 95%CI 1.18,-9.60; p=0.023), the presence of co-morbidities (OR 2.00, 95%CI 1.10, 3.62; p=0.022), and Chinese (as compared to Malay and Indian) ethnicity but not with either functional dyspepsia, irritable bowel syndrome, gallstone disease, Helicobacter pylori infection, or gender.

CONCLUSION

Duodenal eosinophilia was associated with symptomatic erosive GERD, the presence of co-morbidities, and Chinese ethnicity but not with undifferentiated functional dyspepsia.

National census of UK endoscopy services 2021

INTRODUCTION

The Joint Advisory Group on Gastrointestinal (GI) Endoscopy (JAG) biennial census provides a unique view of UK endoscopy. The 2021 census was conducted to understand the impact of ongoing pressures, highlighted in the previous census, as well as COVID-19.

METHODS

The census was sent to all JAG-registered services in April 2021. Data were analysed across the domains of activity, waiting time targets, workforce, COVID-19, safety, GI bleeding, anaesthetic support, equipment and decontamination. Statistical methods were used to determine associations between domain-specific outcome variables and core demographic data.

RESULTS

321 services completed the census (79.2% response rate). In the first 3 months of 2021, 57.9% of NHS services met urgent cancer waits, 17.9% met routine waits and 13.4% met surveillance waits. Workforce redeployment was the predominant reason cited for not meeting targets. There were significant regional differences in the proportion of patients waiting 6 or more weeks (p=0.001). During the pandemic, 64.8% of NHS services had staff redeployed and there was a mean sickness rate of 8.5%. Services were, on average, at 79.3% activity compared with 2 years ago. JAG-accredited services are more likely to meet urgent cancer waits, with a lower proportion of patient waiting 6 weeks or more (p=0.03). Over 10% of services stated that equipment shortage interfered with service delivery.

CONCLUSIONS

Services are adapting to continued pressure and there are signs of a focused response to demand at a time of ongoing uncertainty. This census' findings will inform ongoing guidance from JAG and relevant stakeholders.

Women in gastroenterology: the UK trainee experience

Introduction

Compared with other medical specialties, there are lower numbers of female trainees and lower rates of flexible working in gastroenterology. This study aims to examine the experience of male and female trainees to understand specialty demographics and the experience of training.

Methods

Gastroenterology training data were obtained from the British Society of Gastroenterology (BSG) trainee surveys from 2014, 2018 and 2020, and from the Royal College of Physicians Medical Workforce unit between 2011 and 2019. Data on endoscopy measures from 2011 to 2021 were obtained from the Joint Advisory Group (JAG) on gastrointestinal endoscopy, including the JAG Endoscopy training system and the National Endoscopy Database. Data were segregated and compared by gender.

Results

The percentage of female gastroenterology trainees remains at around 40%, largely unchanged over the previous decade. From the BSG trainee survey, 29.5% of women have flexible working patterns compared with 2.6% of men (p<0.001), which is lower than other medical specialties. Less than half of female trainees felt confident about their job prospects once they qualify. A greater proportion of male than female trainees achieved provisional colonoscopy certification during training (55% vs 45%, p=0.005) and female trainees took longer to certify than male trainees (63 months vs 56 months, p=0.004). The total length of training time from primary medical qualification to consultancy was the same for men and women.

Conclusion

Changes must be addressed from a national and institutional level to address equitable access to national training programmes and equality of outcome for male and female trainees.

JAG consensus statements for training and certification in oesophagogastroduodenoscopy

INTRODUCTION

Training and quality assurance in oesophagogastroduodenoscopy (OGD) is important to ensure competent practice. A national evidence-based review was undertaken to update and develop standards and recommendations for OGD training and certification.

METHODS

Under the oversight of the Joint Advisory Group (JAG), a modified Delphi process was conducted with stakeholder representation from British Society of Gastroenterology, Association of Upper Gastrointestinal Surgeons, trainees and trainers. Recommendations on OGD training and certification were formulated following literature review and appraised using Grading of Recommendations Assessment, Development and Evaluation. These were subjected to electronic voting to achieve consensus. Accepted statements were incorporated into the updated certification pathway.

RESULTS

In total, 32 recommendation statements were generated for the following domains: definition of competence (4 statements), acquisition of competence (12 statements), assessment of competence (10 statements) and post-certification support (6 statements). The consensus process led to following certification criteria: (1) performing ≥250 hands-on procedures; (2) attending a JAG-accredited basic skills course; (3) attainment of relevant minimal performance standards defined by British Society of Gastroenterology/Association of Upper Gastrointestinal Surgeons of Great Britain and Ireland, (4) achieving physically unassisted D2 intubation and J-manoeuvre in ≥95% of recent procedures, (5) satisfactory performance in formative and summative direct observation of procedural skills assessments.

CONCLUSION

The JAG standards for diagnostic OGD have been updated following evidence-based consensus. These standards are intended to support training, improve competency assessment to uphold standards of practice and provide support to the newly-independent practitioner.

A retrospective audit of endoscopic duodenal biopsies to uncover undetected Coeliac disease in Malaysian patients

BACKGROUND

Coeliac disease, an autoimmune enteropathy related to gluten sensitivity was hitherto thought to be rare in Asia. Recent data however suggests that Celiac disease may be under-diagnosed in Asia.

OBJECTIVE

The aim of this audit was to determine the frequency of histological changes compatible with Coeliac disease among patients undergoing elective diagnostic oesaphago-gastro-duodenoscopy (OGDS) under the care of a single practitioner in a Malaysian hospital.

MATERIALS AND METHODS

The archived endoscopically obtained duodenal biopsy specimens of 241 consecutive Malaysian subjects undergoing elective diagnostic (OGDS) were reviewed by a pathologist blinded to the clinical data. Based on intra-epithelial lymphocyte counts, crypt hyperplasia and villous atrophy, each subject was assigned to one of the categories of the Modified Marsh classification for the histological diagnosis of Coeliac disease. The clinical charts of all subjects were reviewed by a single gastroenterologist blinded to the findings of the histological review.

RESULTS

Of the 241 study subjects, 132 (54.8%) were females. There were 56 (23.2%) Malays, 90 (37.3%) Chinese, 88 (36.5%) Indians and seven (2.9%) from the other category. The median age of the study sample was 49 years (range 15- 88 years). The OGDS was done as part of screening in 15(6.2%) subjects while in the remaining it was part of the investigation of a clinical problem. Based on histological findings, none of the subjects could be assigned to a modified Marsh class of >1. The prevalence of histological changes compatible with Coeliac disease in the study was 0% (binomial exact one-sided 97.5 % confidence interval 0- 1.52%).

CONCLUSION

In conclusion, this audit provides no evidence that active Coeliac disease is significantly under-detected among symptomatic patients presenting for diagnostic OGDS. The possibility that a significant number may have potential coeliac disease cannot be excluded.

Joint Advisory Group on Gastrointestinal Endoscopy (JAG) framework for managing underperformance in gastrointestinal endoscopy

Underperformance can be defined as performance which persistently falls below a desired minimum standard considered acceptable for patient care. Within gastrointestinal endoscopy, underperformance may be multifactorial, related to an individual's knowledge, skills, attitudes, health or external factors. If left unchecked, underperformance has the potential to impact on care and ultimately patient safety. Managing underperformance should be a key attribute of high-quality endoscopy service, as recognised in the Joint Advisory Group on Gastrointestinal Endoscopy (JAG) accreditation process. However, it is recognised that not all services have robust mechanisms to do this. This article provides the JAG position on managing underperformance in endoscopy, defined through a practical framework. This follows a stepwise process of detecting underperformance, verification, identification of additional causative factors, providing support and reassessment. Detection and verification of issues may require use of multiple evidence sources, including performance data, feedback and appraisal reports. Where technical underperformance is identified, this should be risk stratified by potential risk to patient safety. Support should be tailored to each individual case based on the type of underperformance detected, any causative factors with an action plan developed. Support may include coaching, mentoring, training and upskilling. Wider support from the medical director's office or external services may also be required. Monitoring and reassessment is a crucial part of the overall process.

Bowel cancer screening workforce survey: developing the endoscopy workforce for 2025 and beyond

AIM

The demand for bowel cancer screening (BCS) is expected to increase significantly within the next decade. Little is known about the intentions of the workforce required to meet this demand. The Joint Advisory Group on Gastrointestinal Endoscopy (JAG), the British Society of Gastroenterology (BSG) and Association of Coloproctology of Great Britain and Ireland (ACPGBI) developed the first BCS workforce survey. The aim was to assess endoscopist career intentions to aid in future workforce planning to meet the anticipated increase in BCS colonoscopy.

METHODS

A survey was developed by JAG, BSG and ACPGBI and disseminated to consultant, clinical and trainee endoscopists between February and April 2020. Descriptive and comparative analyses were undertaken, supported with BCS data.

RESULTS

There were 578 respondents. Screening consultants have a median of one programmed activity (PA) per week for screening, accounting for 40% of their current endoscopy workload. 38% of current screening consultants are considering giving up colonoscopy in the next 2-5 years. Retirement (58%) and pension issues (23%) are the principle reasons for this. Consultants would increase their screening PAs by 70% if able to do so. The top three activities that endoscopists would relinquish to further support screening were outpatient clinics, acute medical/surgical on call and ward cover. An extra 155 colonoscopists would be needed to fulfil increased demand and planned retirement at current PAs.

CONCLUSION

This survey has identified a serious potential shortfall in screening colonoscopists in the next 5-10 years due to an ageing workforce and job plan pressures of aspirant BCS colonoscopists. We have outlined potential mitigations including reviewing job plans, improving workforce resources and supporting accreditation and training.

'Case of the month': a novel way to learn from endoscopy-related patient safety incidents

Patient safety incidents (PSIs) are unintended or unexpected incidents which can or do lead to patient harm. The Joint Advisory Group on Gastrointestinal Endoscopy (JAG) acknowledges that PSIs should be reviewed by endoscopy services and learning shared among staff. It is recognised that more could be done to promote shared learning as outlined by the JAG 'Improving Safety and Reducing Error in Endoscopy' strategy. The 'Case of the month' series aims to provide a broad selection of cases and subsequent learning that can be shared among services and their workforce. This review focuses on five case vignettes that highlight a variety of PSIs in endoscopy. A structured approach, based on incident analysis methodology, is applied to each case to categorise PSIs and develop learning points. Learning is directed toward the individual, team and healthcare organisation. A selection of methods to disseminate learning at local, regional and national levels are also described.

Teamworking in endoscopy: a human factors toolkit for the COVID-19 era

BACKGROUND

Endoscopy services have had to rapidly adapt their working practices in response to COVID-19. As recovery of endoscopy services proceeds, our workforce faces numerous challenges that can impair effective teamworking. We designed and developed a novel toolkit to support teamworking in endoscopy during the pandemic.

METHODS

A human factors model was developed to understand the impact of COVID-19 on endoscopy teams. From this, we identified a set of key teamworking goals, which informed the development of a toolkit to support several team processes. The toolkit was refined following expert input and refinement over a 6-week period.

RESULTS

The toolkit consists of four cognitive aids that can be used to support team huddles, briefings, and debriefs, alongside techniques to optimize endoscopic nontechnical skills across the patient-procedure pathway. We describe the processes that local endoscopy units can employ to implement this toolkit.

CONCLUSION

A toolkit of cognitive aids, based on human factors principles, may be useful in supporting teams, helping them adapt to working safely in the era of COVID-19.

Improving safety and reducing error in endoscopy (ISREE): a survey of UK services

BACKGROUND

The Joint Advisory Group on Gastrointestinal Endoscopy (JAG) 'Improving Safety and Reducing Error in Endoscopy' (ISREE) strategy was developed in 2018. In line with the strategy, a survey was conducted within the JAG census in 2019 to gain further insights and understanding of key safety-related areas within UK endoscopy.

METHODS

Questions were developed using the ISREE strategy as a guide and adapted by key JAG stakeholders. They were incorporated into the 2019 JAG census of UK endoscopy services. Quantitative and qualitative statistical methods were employed to analyse the results.

RESULTS

There was a 68% response rate. There was regional variability in the provision of out-of-hours GIB services (p<0.001). Across 1 month, 1535 incidents were reported across all services. There was a significantly higher proportion of reported incidents in acute services compared with others (p<0.001). Technical and training incidents were likely to be reported significantly differently to all other incident types. 74% of services have an endoscopy-specific sedation policy and 42% have a named sedation or anaesthetic lead for endoscopy. Services highlighted a desire for more anaesthetic-supported lists. Only 66% of services stated they have an effective strategy for supporting upskilling of endoscopists. Across acute services, 56% have access to human factors and endoscopic non-technical skills (ENTS) training. Patient feedback is used in several ways to improve services, develop training and promote shared learning among endoscopy users.

CONCLUSIONS

The census provides a benchmark for key safety-related characteristics of endoscopy services. These results have highlighted key areas to develop, guided by the ISREE strategy.

National census of UK endoscopy services in 2019

INTRODUCTION

The 2017 Joint Advisory Group on Gastrointestinal (GI) Endoscopy (JAG) census highlighted the pressure endoscopy services were under in meeting national targets and the factors behind this. In 2019, JAG conducted a further national census of endoscopy services to understand trends in activity, workforce and waiting time targets.

METHODS

In April 2019, the census was sent to all eligible JAG-registered services. Collated data were analysed through various statistical methods. A further comparative dataset was created using available submissions from the 2017 census matched to services in the current census.

RESULTS

There was a 68% response rate (322/471). There has been a 12%-15% increase in activity across all GI procedures with largest increases in bowel cancer screening. Fewer services are meeting waiting time targets compared with 2017, with endoscopist, nursing and physical capacity cited as the main reasons. Services are striving to improve capacity: 80% of services have an agreed business plan to meet capacity and the number using insourcing has increased from 13% to 20%. The workforce has increased, with endoscopist numbers increasing by 15%, nurses and allied health professionals by 14% and clerical staff by 30%.

CONCLUSIONS

The 2019 JAG census is the most recent and extensive survey of UK endoscopy services. There is a clear trend of increasing activity with fewer services able to meet national waiting time targets than 2 years ago. Services have increased their workforce and improved planning to stem the tide but there remains a continued pressure to deliver high quality, safe endoscopy. In light of the COVID-19 pandemic, JAG recognises that these pressures will be severely exacerbated and waiting time targets for accreditation will need adjustment and tolerance during the evolution and recovery from the pandemic.

Development and impact of an endoscopic non-technical skills (ENTS) behavioural marker system

Background

Non-technical skills (NTS) are crucial to effective team working in endoscopy. Training in NTS has been shown to improve team performance and patient outcomes. As such, NTS training and assessment are now considered essential components of the endoscopy quality assurance process. Across the literature, other specialties have achieved this through development of behavioural marker systems (BMS). BMS provide a framework for assessing, training and measuring the NTS relevant to healthcare individuals and team. This article describes the development and impact of a novel BMS for endoscopy: the endoscopic non-technical skills (ENTS) system.

Methods

The initial NTS taxonomy for endoscopy was created through a combination of literature review, staff focus groups and semi-structured interviews, incorporating the critical decision method. Framework analysis was conducted with three individual coders and generated a skills list which formed the preliminary taxonomy. Video observation of Bowel Cancer Screening endoscopists was used to identify exemplar behaviours which were mapped to relevant skills in the NTS taxonomy. Behavioural descriptors, derived from video data, were added to form the basis of the ENTS system.

Results

A taxonomy of 33 skills in 14 separate categories were identified through framework analysis. Following video analysis and behaviour mapping, 4 overarching categories and 13 behavioural elements were identified which formed the ENTS framework. The endoscopy (directly observed procedural skills) 4-point rating scale was added to create the final ENTS system. Since its development in 2010, the ENTS system has been validated in the assessment of endoscopy for trainees nationally. ENTS informs a number of training initiatives, including a national strategy to improve NTS for all endoscopists.

Conclusions

The ENTS system is a clinically relevant tool, validated for use in trainee assessment. The use of ENTS will be important to the future of training and quality assurance in endoscopy.

Variability in cecal intubation rate by calculation method: a call for standardization of key performance indicators in endoscopy

BACKGROUND AND AIMS

The cecal intubation rate (CIR) is a widely accepted key performance indicator (KPI) in colonoscopy but lacks a universal calculation method. We aimed to assess whether differences in CIR calculation methods could have an impact on perceived trainee outcomes.

METHODS

A systematic review of CIR calculation methods was conducted on major societal guidelines (United Kingdom, European Society of Gastrointestinal Endoscopy [ESGE] and American Society for Gastrointestinal Endoscopy [ASGE]) and trainee-inclusive studies. Trainees awarded colonoscopy certification between June 2011 and 2016 were identified from the United Kingdom e-portfolio and selected as a validation cohort. For each trainee, both the crude and unassisted CIR were calculated for 50 post-certification procedures using definitions from the 3 international guidelines. The resulting CIRs, and the proportions of endoscopists failing to meet the minimum standard of CIR ≥90%, were then compared across these definitions.

RESULTS

Across the 3 guidelines and 37 eligible studies identified, differences in CIR calculation methodology were demonstrated. These related to adjustment criteria (18 studies) and whether unassisted CIR was stipulated (18 studies). In the validation cohort of 733 trainees (36,650 procedures), the median crude CIR ranged from 96% (ESGE) to 98% (ASGE) (P < .001) and whether unassisted CIR was specified (ESGE, 94%; ASGE, 96%; P < .001). The proportion of trainees failing to achieve CIR ≥90% varied significantly across the different definitions, from 4.9% for the crude ASGE definition to 18.6% for the unassisted ESGE definition (P < .001).

CONCLUSIONS

CIR calculation methods vary among guidelines and research studies; this has an impact on trainee performance measures. With CIR used as an example, this study highlights the need for standardized definitions and calculations of KPIs in endoscopy.

Improving safety and reducing error in endoscopy: simulation training in human factors

Patient safety incidents occur throughout healthcare and early reports have exposed how deficiencies in 'human factors' have contributed to mortality in endoscopy. Recognising this, in the UK, the Joint Advisory Group for Gastrointestinal Endoscopy have implemented a number of initiatives including the 'Improving Safety and Reducing Error in Endoscopy' (ISREE) strategy. Within this, simulation training in human factors and Endoscopic Non-Technical Skills (ENTS) is being developed. Across healthcare, simulation training has been shown to improve team skills and patient outcomes. Although the literature is sparse, integrated and in situ simulation modalities have shown promise in endoscopy. Outcomes demonstrate improved individual and team performance and development of skills that aid clinical practice. Additionally, the use of simulation training to detect latent errors in the working environment is of significant value in reducing error and preventing harm. Implementation of simulation training at local and regional levels can be successfully achieved with collaboration between organisational, educational and clinical leads. Nationally, simulation strategies are a key aspect of the ISREE strategy to improve ENTS training. These may include integration of simulation into current training or development of novel simulation-based curricula. However used, it is evident that simulation training is an important tool in developing safer endoscopy.

Enteropathy-associated T-cell lymphoma: An extremely rare cause of chronic diarrhoea

Chronic diarrhoea in tropical countries may be due to a myriad of causes from infective to non-infective. This case report illustrates the challenges faced in the investigation of a middle-age Chinese gentleman who presented with chronic diarrhoea and weight loss. The diagnosis of type II enteropathy-associated T-cell lymphoma (EATL) was finally made. The diagnosis of EATL was least suspected as the condition is almost unheard of in this part of the world. The epidemiology, presentation, diagnosis, management and prognosis of this rare condition are discussed.

Note: Dynamic meso-scale full field surface deformation measurement of heterogeneous materials

A dynamic experiment at mesoscale is developed to measure local deformation and strain in granular materials at high temporal and spatial resolutions. The experimental setup is comprised of a high-speed camera along with a high magnification extension tube. The method is demonstrated by measuring the full field strain across and in the boundary of the crystals at a high temporal resolution in polymer bonded sugar crystals and glass beads filled epoxy particulate composite specimens under dynamic loading. In both cases, the local strain heterogeneity is captured successfully. The measured strain and deformation field can be further used to obtain the relative motion of each crystal, crystal rotation, and the relative displacement between the polymer interface and the crystal, which are very critical to understand the local failure mechanisms in heterogeneous materials.

Magnetic resonance enterography: a pictorial review of Crohn's disease

Use of magnetic resonance enterography has significantly increased and its role as an adjunct to ileocolonoscopy is best practice, particularly in the evaluation of Crohn's disease. This article reviews magnetic resonance enterography, and describes common findings related to Crohn's disease and unexpected extra-intestinal findings.

DMP1-derived peptides promote remineralization of human dentin

Remineralization of dentin during dental caries is of considerable clinical interest. Dentin matrix protein 1 (DMP1) is a non-collagenous calcium-binding protein that plays a critical role in biomineralization. In the present study, we tested if peptides derived from DMP1 can be used for dentin remineralization. Peptide pA (pA, MW = 1.726 kDa) and peptide pB (pB, MW = 2.185), containing common collagen-binding domains and unique calcium-binding domains, were synthesized by solid-phase chemistry. An extreme caries lesion scenario was created by collagenase digestion, and the biomineral-nucleating potential of these peptides was ascertained when coated on collagenase-treated dentin matrix and control, native human dentin matrix under physiological levels of calcium and phosphate. Scanning electron microscopy analysis suggests that peptide pB was an effective nucleator when compared with pA. However, a 1:4 ratio of pA to pB was determined to be ideal for dentin remineralization, based on hydroxyapatite (HA) morphology and calcium/phosphorus ratios. Interestingly, HA was nucleated on collagenase-challenged dentin with as little as 20 min of 1:4 peptide incubation. Electron diffraction confirmed the presence of large HA crystals that produced a diffraction pattern indicative of a rod-like crystal structure. These findings suggest that DMP1-derived peptides may be useful to modulate mineral deposition and subsequent formation of HA when exposed to physiological concentrations of calcium and phosphate.

DSPP contains an IRES element responsible for the translation of dentin phosphophoryn

The major phosphoprotein in dentin is the aspartic acid and serine-rich protein called dentin phosphophoryn (DPP). DPP appears to be synthesized as a part of a larger compound protein, dentin sialophosphoprotein (DSPP). DSPP has never been isolated or detected in dentin extracts. It is now evident that DSPP is a chimeric protein composed of 3 parts: dentin sialoprotein (DSP), DPP, and dentin glycoprotein (DGP). Previous reports have suggested that the BMP1 protease is responsible for processing DSPP. However, unequal amounts of these products are present in the dentin matrix. Here, we provide evidence for an internal ribosome entry site in the DSPP gene that directs the synthesis of DPP. This mechanism would account for unequal amounts of intracellular DSP and DPP. The internal ribosomal entry site (IRES) activity varied in different cell types, suggesting the presence of additional regulatory elements during the translational regulation of DPP. Further, we provide evidence that DPP is transported to the extracellular matrix (ECM) through exosomes. Using tissue recombination and lentivirus-mediated gain-of-function approaches, we also demonstrate that DPP is essential for the formation of well-defined tooth structures with mineralized dentin matrix.

A pilot study of the safety and efficacy of thymosin alpha 1 in augmenting immune reconstitution in HIV-infected patients with low CD4 counts taking highly active antiretroviral therapy

To study the safety and efficacy of thymosin alpha1 in stimulating immune reconstitution in combination with highly active antiretroviral therapy (HAART), a phase II randomized, controlled open-label trial of subcutaneous thymosin alpha1 was undertaken for 12 weeks. Twenty clinically stable patients with viral loads <400 copies/ml and CD4 counts less than 200 cells/microl were randomized to receive 3.2 mg thymosin alpha 1 subcutaneous injections twice weekly or no injections for 12 weeks. CD4 and CD8 counts, CD45 RO+ and RA+ subsets and signal joint T cell receptor excision circles (sjTREC) in peripheral blood mononuclear cells (PBMCs) were measured every 2 weeks. Thirteen patients received thymosin alpha 1 and seven were controls. Thymosin alpha 1 was well tolerated and there were no serious adverse events. There was no significant difference between the thymosin alpha1 and control groups in CD4, CD8 and CD45 lymphocyte subset changes at week 12; however, PBMC sjTREC levels increased significantly in the thymosin alpha 1-treated patients compared to controls at week 12. In conclusion, the increase in PBMC sjTREC levels in patients taking thymosin alpha1 may represent enhanced immune reconstitution; however, the clinical benefits and long-term consequences remain to be determined.

The reaction between plasmin and C1-inhibitor results in plasmin inhibition by the serpin mechanism

C1-inhibitor is an important inhibitor of plasma kallikrein and C1, but also has inhibitory activity against numerous other plasma proteinases such as plasmin. The relevance of plasmin inhibition by the C1-inhibitor has been debated, with some evidence showing that plasmin causes significant proteolysis of C1-inhibitor. In the present study, we show that C1-inhibitor in its native state will inhibit plasmin without being significantly degraded, in a manner typical of all serpin reactions. However, if C1-inhibitor is in a denatured polymeric state (as can easily occur during storage, or as produced by heating of the native protein), it will be extensively degraded by plasmin. In addition, we show that hydrophobic interaction chromatography is an effective method to remove trace contaminants of inactive C1-inhibitor polymers.

Reaction Mechanism for Mammalian Pyruvate Dehydrogenase Using Natural Lipoyl Domain Substrates

The pyruvate dehydrogenase (E1) component of the pyruvate dehydrogenase complex (PDC) catalyzes a two-step reaction. Recombinant production of substrate amounts of the lipoyl domains of the dihydrolipoyl transacetylase (E2) component of the mammalian PDC allowed kinetic characterization of the rapid physiological reaction catalyzed by E1. Using either the N-terminal (L1) or the internal (L2) lipoyl domain of E2 as a substrate, analyses of steady state kinetic data support a ping pong mechanism. Using standard E1 preparations, Michaelis constants (Km) were 52 +/- 14 microM for L1 and 24.8 +/- 3.8 microM for pyruvate and k(cat) was 26.3 s(-1). With less common, higher activity preparations of E1, the Km values were > or =160 microM for L1 and > or =35 microM for pyruvate and k(cat) was > or =70 s(-1). Similar results were found with the L2 domain. The best synthetic lipoylated-peptide (L2 residues 163-177) was a much poorer substrate (Km > or =15 mM, k(cat) approximately equals 5 s(-1); k(cat)/Km decreased >1,500-fold) than L1 or L2, but a far better substrate in the E1 reaction than free lipoamide (k(cat)/Km increased >500-fold). Each lipoate source was an effective substrate in the dihydrolipoyl dehydrogenase (E3) reaction, but E3 had a lower Km for the L2 domain than for lipoamide or the lipoylated peptides. In contrast to measurements with slow E1 model reactions that use artificial acceptors, we confirmed that the natural E1 reaction, using lipoyl domain acceptors, was completely inhibited (>99%) by phosphorylation of E1 and the phosphorylation strongly inhibited the reverse of the second step catalyzed by E1. The mechanisms by which phosphorylation interferes with E1 activity is interpreted based on accrued results and the location of phosphorylation sites mapped onto the 3-D structure of related alpha-keto acid dehydrogenases.

Nephrectomy during operative management of retroperitoneal sarcoma

BACKGROUND

Complete resection of a retroperitoneal sarcoma often requires removal of adjacent organs. In this study we evaluated the role of nephrectomy during operation for retroperitoneal sarcoma.

METHODS

Between July 1982 and July 1995, 75 of the 371 (20%) patients who underwent resection of retroperitoneal sarcoma at MSKCC underwent concommitant nephrectomy. Data concerning the reasons for nephrectomy, degree of sarcomatous renal involvement, and survival were retrospectively analyzed.

RESULTS

Fifty-four patients (72%) underwent nephrectomy during the initial resection, and 21 (28%) during a resection of a recurrent or persistent tumor. The most common reason for nephrectomy was total encasement by sarcoma (n = 40; 53%), followed by dense adherence of the tumor to the kidney (n = 21; 28%), and the direct invasion of the kidney by tumor (n = 2; 3%). Pathology demonstrated an absence of kidney invasion in the majority of cases (55 of 75; 73%). Renal capsular invasion was present in 11 of 75 (15%), renal parenchymal invasion in 7 of 75 (9%), and renal vein invasion in 2 of 75 (3%) of cases. There were no significant differences in survival based on degree of sarcoma involvement of the kidney, tumor grade, or whether the resection was for primary or recurrent disease. The 53 patients who underwent a complete gross resection of all tumor had a significantly improved long-term survival compared to the 20 patients who did not (50% versus 20% DFS at 5 years, respectively; p < 0.001).

CONCLUSIONS

Decisions for concomitant nephrectomy during resection of retroperitoneal sarcoma should be based on whether this maneuver will provide a complete resection of all gross tumor, in which case the long-term disease-free survival of 50% is comparable to the reported 5-year survival of all patients with retroperitoneal sarcoma who are completely resected.

Lipoyl domain-based mechanism for the integrated feedback control of the pyruvate dehydrogenase complex by enhancement of pyruvate dehydrogenase kinase activity

To conserve carbohydrate reserves, the reaction of the pyruvate dehydrogenase complex (PDC) must be down-regulated when the citric acid cycle is provided sufficient acetyl-CoA. PDC activity is reduced primarily through increased phosphorylation of its pyruvate dehydrogenase (E1) component due to E1 kinase activity being markedly enhanced by elevated intramitochondrial NADH:NAD+ and acetyl-CoA:CoA ratios. A mechanism is evaluated in which enhanced kinase activity is facilitated by the build-up of the reduced and acetylated forms of the lipoyl moieties of the dihydrolipoyl acetyltransferase (E2) component through using NADH and acetyl-CoA in the reverse of the downstream reactions of the complex. Using a peptide substrate, kinase activity was stimulated by these products, ruling out the possibility kinase activity is increased due to changes in the reaction state of its substrate, E1 (thiamin pyrophosphate). Each E2 subunit contains two lipoyl domains, an NH2-terminal (L1) and the inward lipoyl domain (L2), which were individually produced in fully lipoylated forms by recombinant techniques. Although reduction and acetylation of the L1 domain or free lipoamide increased kinase activity, those modifications of the lipoate of the kinase-binding L2 domain gave much greater enhancements of kinase activity. The large stimulation of the kinase generated by acetyl-CoA only occurred upon addition of the transacetylase-catalyzing (lipoyl domain-free) inner core portion of E2 plus a reduced lipoate source, affirming that acetylation of this prosthetic group is an essential mechanistic step for acetyl-CoA enhancing kinase activity. Similarly, the lesser stimulation of kinase activity by just NADH required a lipoate source, supporting the need for lipoate reduction by E3 catalysis. Complete enzymatic delipoylation of PDC, the E2-kinase subcomplex, or recombinant L2 abolished the stimulatory effects of NADH and acetyl-CoA. Retention of a small portion of PDC lipoates lowered kinase activity but allowed stimulation of this residual kinase activity by these products. Reintroduction of lipoyl moieties, using lipoyl protein ligase, restored the capacity of the E2 core to support high kinase activity along with stimulation of that activity up to 3-fold by NADH and acetyl-CoA. As suggested by those results, the enhancement of kinase activity is very responsive to reductive acetylation with a half-maximal stimulation achieved with approximately 20% of free L2 acetylated and, from an analysis of previous results, with acetylation of only 3-6 of the 60 L2 domains in intact PDC. Based on these findings, we suggest that kinase stimulation results from modification of the lipoate of an L2 domain that becomes specifically engaged in binding the kinase. In conclusion, kinase activity is attenuated through a substantial range in response to modest changes in the proportion of oxidized, reduced, and acetylated lipoyl moieties of the L2 domain of E2 produced by fluctuations in the NADH:NAD+ and acetyl-CoA:CoA ratios as translated by the rapid and reversible E3 and E2 reactions.

Assessment of nutrient intake and associated factors in an Indian elderly population

A group of 420 elderly people (163 women and 257 men with a mean age of 65 years) from urban and rural populations in India were selected for the study. The caloric intake of 93.3% was less than the recommended allowance, the mean daily caloric intake being 1191 kcal in men and 928 kcal in women. Except for calcium, all nutrients were deficient in their diet. Illiteracy (53%), lack of knowledge regarding daily allowances of nutrients (95%), poor economic background (46.7%), and breaking down of joint family system (63%) were possible associated factors examined.

Critical role of a lipoyl cofactor of the dihydrolipoyl acetyltransferase in the binding and enhanced function of the pyruvate dehydrogenase kinase

Mammalian pyruvate dehydrogenase kinase binds to the lipoyl domain region of the core structure forming dihydrolipoyl acetyltransferase (E2) subunits. The bound kinase has a greatly enhanced rate in phosphorylating E2-bound pyruvate dehydrogenase (E1) tetramers versus the rate at which resolved kinase phosphorylates dissociated E1. This E2-activated kinase function was completely prevented by selective alkylation of reduced lipoyl groups while kinase and E1 binding to the E2 core were retained. Selective removal of lipoyl cofactors from intact E2 by treatment with Enterococcus faecalis lipoamidase decreased kinase activity by 4-fold and caused selective release of a major portion of the kinase from E2 in a sucrose-step gradient procedure. Selective and reversible modification of the lipoyl groups of E2 subunits also allowed the kinase to be dissociated under mildly chaotropic conditions. Thus, the lipoyl prosthetic group on one of the two lipoyl domains of E2 subunits is critically important for maintaining E2-activated kinase function and contributes to binding of the kinase to E2. Since removal of the lipoyl group weakened kinase binding to E2 more than modifying lipoyl thiols, it is suggested that the hydrophobic inner portion of the lipoyl conjugate (i.e., lysine carbons and C1 to C5 of the lipoic acid) is important in the binding of the kinase.