Senior trainee as endoscopy teacher: impact on trainee learning and attending experience.

Objective: Training in how to effectively teach endoscopy is not included in most gastroenterology (GI) training programme curricula, yet many gastroenterologists are expected to teach endoscopy in their careers. Near-peer teaching could help senior GI trainees learn how to teach endoscopy and have benefits for junior trainees. We performed a qualitative study of a peer teaching initiative where senior trainees taught endoscopy to junior trainees under attending supervision. Design: We observed endoscopy sessions where the senior trainee taught a junior trainee under attending supervision, and then conducted individual interviews with the senior trainee teacher, junior trainee learner and attending to characterise affordances and barriers to learning. We performed thematic analysis on anonymised interview transcripts. Results: 10 observations and 30 interviews were completed. Junior trainees reported senior trainees more approachable than attendings and explained concepts in more understandable ways. Senior trainees reported the teaching role improved skill at both teaching and performing endoscopy. Attendings reported positive impressions of the experience for senior trainees, and generally positive impressions with some reservations of the experience for junior trainees. A few barriers to learning were reported, but they were generally perceived as being outweighed by affordances. An area for improvement was setting clear expectations for senior trainee and attending roles before the session. Conclusion: Near-peer endoscopy teaching was feasible and provided perceived affordances for junior and senior trainees alike, with few barriers. Incorporating formal training in teaching endoscopy into GI training programme curricula may produce both better endoscopists and better endoscopy teachers.

Utility and impact of magnetic resonance elastography in the clinical course and management of chronic liver disease.

We aimed to characterize scenarios where magnetic resonance elastography (MRE) of the liver was ordered and its impact on clinical course and management. 96 consecutive MRE examinations and subsequent encounters over 14 months were reviewed. Indication for MRE of the liver and subsequent management were abstracted from the medical record. In all cases, non-invasive assessment of liver fibrosis was the primary indication and at least one additional rationale was noted. There was a significant decrease in recommendations to undergo liver biopsy after MRE. Additionally, a greater percentage of those recommended to undergo biopsy completed the procedure after discussion of the results. Given the significant cost and rare but serious risks of liver biopsy, MRE of the liver provides an attractive, safer alternative that may have a comparable impact on management, or select cases where biopsy is essential to guide management. We demonstrate the versatility of MRE in real-world hepatology practice, including its utility as a non-invasive surrogate for liver biopsy.

Creation of an ustekinumab external control arm for Crohn's disease using electronic health records data: A pilot study.

BACKGROUND: Randomized trials are the gold-standard for clinical evidence generation, but they can sometimes be limited by infeasibility and unclear generalizability to real-world practice. External control arm (ECA) studies may help address this evidence gaps by constructing retrospective cohorts that closely emulate prospective ones. Experience in constructing these outside the context of rare diseases or cancer is limited. We piloted an approach for developing an ECA in Crohn's disease using electronic health records (EHR) data. METHODS: We queried EHR databases and manually screened records at the University of California, San Francisco to identify patients meeting the eligibility criteria of TRIDENT, a recently completed interventional trial involving an ustekinumab reference arm. We defined timepoints to balance missing data and bias. We compared imputation models by their impacts on cohort membership and outcomes. We assessed the accuracy of algorithmic data curation against manual review. Lastly, we assessed disease activity following treatment with ustekinumab. RESULTS: Screening identified 183 patients. 30% of the cohort had missing baseline data. Nonetheless, cohort membership and outcomes were robust to the method of imputation. Algorithms for ascertaining non-symptom-based elements of disease activity using structured data were accurate against manual review. The cohort consisted of 56 patients, exceeding planned enrollment in TRIDENT. 34% of the cohort was in steroid-free remission at week 24. CONCLUSION: We piloted an approach for creating an ECA in Crohn's disease from EHR data by using a combination of informatics and manual methods. However, our study reveals significant missing data when standard-of-care clinical data are repurposed. More work will be needed to improve the alignment of trial design with typical patterns of clinical practice, and thereby enable a future of more robust ECAs in chronic diseases like Crohn's disease.

Persistent but Labile Synaptic Plasticity at Excitatory Synapses.

Short-term synaptic plasticity contributes to many computations in the brain and allows synapses to keep a finite record of recent activity. Here we have investigated the mechanisms underlying an intriguing form of short-term plasticity termed labile LTP, at hippocampal and PFC synapses in male rats and male and female mice. In the hippocampus, labile LTP is triggered by high-frequency activation of presynaptic axons and is rapidly discharged with further activation of those axons. However, if the synapses are quiescent, they remain potentiated until further presynaptic activation. To distinguish labile LTP from NMDAR-dependent forms of potentiation, we blocked NMDARs in all experiments. Labile LTP was synapse-specific and was accompanied by a decreased paired pulse ratio, consistent with an increased release probability. Presynaptic Ca2+ and protein kinase activation during the tetanus appeared to be required for its initiation. Labile LTP was not reversed by a PKC inhibitor and did not require either RIM1α or synaptotagmin-7, proteins implicated in other forms of presynaptic short-term plasticity. Similar NMDAR-independent potentiation could be elicited at synapses in mPFC. Labile LTP allows for rapid information storage that is erased under controlled circumstances and could have a role in a variety of hippocampal and prefrontal cortical computations related to short-term memory.SIGNIFICANCE STATEMENT Changes in synaptic strength are thought to represent information storage relevant to particular nervous system tasks. A single synapse can exhibit multiple overlapping forms of plasticity that shape information transfer from presynaptic to postsynaptic neurons. Here we investigate the mechanisms underlying labile LTP, an NMDAR-independent form of plasticity induced at hippocampal synapses. The potentiation is maintained for long periods as long as the synapses are infrequently active, but with regular activation, the synapses are depotentiated. Similar NMDAR-independent potentiation can also be induced at L2/3-to-L5 synapses in mPFC. Labile LTP requires a rise in presynaptic Ca2+ and protein kinase activation but is unaffected in RIM1α or synaptotagmin-7 mutant mice. Labile LTP may contribute to short-term or working memory in hippocampus and mPFC.

Prenatal diagnosis of hypoplastic left heart syndrome in current era.

We sought to evaluate the relation of a prenatal diagnosis (preDx) with morbidity and mortality during the initial hospitalization in a contemporary cohort of patients with hypoplastic left heart syndrome (HLHS). A retrospective study of patients with HLHS presenting from 1999 to 2010 was performed. Patients with genetic disorders or a gestational age <34 weeks or who had intentionally received comfort care only were excluded. Of the 81 patients meeting the study criteria, 49 had a preDx and 32 were diagnosed postnatally (postDx). Birth weight (median 3.0 vs 3.4 kg; p = 0.007) and gestational age (median 38 vs 39 weeks; p <0.001) were lower in the preDx than in the postDx patients. Preoperatively, the postDx patients were intubated more frequently (97% vs 71%, p = 0.004) and ventilated longer (median 96 vs 24 hours, p = 0.005) than the preDx patients. They also had more preoperative acidosis, multiorgan failure, tricuspid valve regurgitation, and right ventricular dysfunction. Of the 73 patients undergoing surgery, no difference in survival was seen between the preDx and postDx groups (91% vs 89%). The median duration of postoperative ventilation was 7 days and the median length of stay was 36 days for the 66 survivors, with no difference between the 2 groups. Postoperative morbidities, including chylothorax and infection, were also similar in the preDx and postDx patients. No studied preoperative factor was associated with death, duration of postoperative ventilation, or length of stay. In conclusion, our recent experience has shown that preDx of HLHS was not associated with a survival advantage, fewer postoperative complications, or shorter length of stay. Improved preoperative status was observed in the preDx patients; however, they were born earlier with a lower birthweight. What effect these factors might have on longer term morbidity remains unknown.