Quantum Unique Ergodicity for Cayley Graphs of Quasirandom Groups

A finite group G is called C-quasirandom (by Gowers) if all non-trivial irreducible complex representations of G have dimension at least C. For any unit ℓ 2 function on a finite group we associate the quantum probability measure on the group given by the absolute value squared of the function. We show that if a group is highly quasirandom, in the above sense, then any Cayley graph of this group has an orthonormal eigenbasis of the adjacency operator such that the quantum probability measures of the eigenfunctions put close to the correct proportion of their mass on suitably selected subsets of the group that are not too small.

A265 TEMPORAL DYNAMICS OF SYMPTOMS AND GUT MICROBIOTA IN EPISODES OF IRRITABLE BOWEL SYNDROME

Background

Irritable bowel syndrome (IBS) is a disorder of gut-brain axis that manifests with chronic abdominal pain, altered bowel habits, and frequent psychiatric comorbidities. Despite mounting evidence showing gut microbiota composition and associated metabolites being altered in IBS, the mechanisms by which they drive the symptoms are unclear. We have previously shown that several IBS symptoms co-occur, that their severity vary among IBS subtypes (10.1093/jcag/gwab049.050), and that several bacterial taxa are differentially modulated during periods of symptom flares and remission. Here we investigate whether the changes in gut microbiome and bacterial metabolites are linked to symptom occurrence and severity.

Purpose

To investigate temporal associations of IBS symptoms with gut microbiota profiles and metabolites.

Method

16S rRNA gene sequencing was performed on stool samples of 28 IBS patients (IBS-D n=20, IBS-C n=8) and 10 healthy controls (HC), collected weekly over a period of 25 weeks, during which gut and mood symptoms were recorded (total of 950 samples). Correlations between principal ordinates obtained from symptom scores and microbiota beta diversity were studied using Procrustes analysis in R. Metabolomics was performed by Mass Spectrometry and analysed using MetaboAnalyst 5.0. Statistical significance was set at p<0.05.

Result(s)

Significant correlation was found between the symptom scores and microbiota beta diversity ordinates over time in 7 patients (5 IBS-D and 2 IBS-C subjects) out of 28 IBS patients. Metabolomics performed on samples selected based on Procrustes analysis and symptom severity scores of individual subjects showed that several pathways are altered in IBS patients (both subtypes) compared to HC, including primary bile acid biosynthesis, beta alanine metabolism, pyrimidine and histidine metabolism. Furthermore, during symptom flares, ornithine, citrulline and gluconic acid vary in IBS-D, while amino acids cysteine, methionine, threonine, and glycine vary in IBS-C subjects.

Conclusion(s)

Our results suggest that IBS symptoms and changes in gut microbiota composition and metabolites must be studied in conjunction, in order to understand the mechanisms underlying IBS pathophysiology. We found that same pathways are altered in IBS subjects irrespective of their subtype, suggestive of a basal metabolic shift in IBS patients. This shift may make them sensitive to further gut microbial modulation of carbohydrate and protein metabolism in IBS-D and IBS-C subjects, respectively, leading to symptom flares. Further analyses are needed to investigate these metabolites and associated bacteria, as they can help identifying subsets of patients with specific disease mechanisms. This will be a steppingstone in moving away from symptom-based subtyping towards mechanism-based grouping and developing effective treatment strategies accordingly.

Disclosure of Interest

None Declared

80 A PILOT POPS SERVICE (PERI-OPERATIVE CARE OF THE OLDER PERSON UNDERGOING SURGERY): A PROMISING START

Background

It is understood that older persons undergoing surgery benefit from Comprehensive Geriatric Assessment (CGA), however these services remain limited in Ireland. Latest guidelines recommend all patients over 65 undergoing surgery should be screened for frailty and receive a CGA if frailty is identified. Our pilot service was to implement this on our acute surgical in-patient ward.

Methods

Baseline data was gathered prior to implementation of our service. Interventions included education, dedicated sessions for geriatrician input on ward, single point of referral and increased signage. Patients identified as living with frailty (Rockwood Clinical Frailty Score (CFS) ≥5) then received CGA. Progress monitored with monthly audit and foundation doctor feedback surveys over a 6-month period.

Results

We have increased the percentage of patients over 65 being screened for frailty from 0% to a peak of 100% over our pilot 6-month period. Foundation doctor surveys showed an improvement in confidence in screening for frailty (19 to 100%) and managing frailty (13 to 80%). They also reported feeling more supported managing these patients (38% to 100%). Focusing on patients with CFS ≥5, we have shown a reduction in length of stay from a mean of 20 days to 11 days, albeit numbers remain small.

Conclusion

By increasing identification of frailty in older patients, we have managed to apply CGA to appropriate patients. Geriatrician input on the surgical ward has also allowed foundation doctors to feel supported and improve confidence in managing patients living with frailty. Furthermore, we have shown a trend towards reduced length of stay. However, our patient numbers remain low and there is a reliance on our team to screen all patients over 65. Our focus moving forward is for the surgical team to screen for frailty allowing us to expand the service to other surgical wards.

Abstract 581: bbT369, a dual-targeted and CBLB gene-edited autologous CART product, demonstrates anti-lymphoma activity in preclinical mouse models

Anti-CD19 CAR T cell therapies have improved outcomes for non-Hodgkin lymphoma (NHL) patients. However, only 30-40% of patients treated with commercially available CART cell therapies obtain long term remission, highlighting the need for more efficacious and durable therapies. Emerging clinical data suggest several failure modes for CD19 CAR T cell therapies: including loss or downregulation of CD19 antigen, loss of co-stimulation pathways on tumor cells, exhaustion of CAR-T cells, and immunosuppressive microenvironments. To overcome these hurdles, we devised the next-generation autologous CAR-T cell therapy bbT369. bbT369 is dual targeted (CD79a/CD20) CAR T cell therapy that uses an OR gate design to limit antigen escape, has split 41BB and CD28 co-stimulatory domain architecture to augment T cell activation, and contains a knock-out of the CBLB gene to enhance potency and reduce T cell exhaustion. Here we report the first results with bbT369, demonstrating anti-lymphoma activity in in vitro assays and in vivo using xenograft mouse models.

We demonstrate that CD79a and CD20 expression is B cell lineage restricted in normal human tissue and confirm that these proteins are co-expressed in diffuse large B cell samples. To target these antigens, we show a split dual-targeting CAR configuration is optimal for bbT369-directed tumor cell killing. Using an engineered megaTAL, we demonstrate high on-target activity of greater than 75% insertions and deletions (Indels) at the CBLB target site using clinical-scale manufacturing processes and low off-target activity (all off-targets less than 0.2%). In in vitro tumor co-culture assays, we show that inclusion of the CBLB gene edit in bbT369 increases Interleukin (IL)-2 production relative to an unedited anti-CD79a/CD20 CAR T cell control. Using various xenograft mouse models, we showed that bbT369 has similar or improved efficacy compared to anti-CD19 CAR drug product, including in low tumor-antigen models. In the Toledo subcutaneous xenograft model, bbT369 showed a 3-fold increase in T cell expansion compared with an unedited anti-CD79a/CD20 dual-targeting CAR T cell control. Furthermore, while a fraction of mice (3/5) receiving the unedited anti-CD79a/CD20 dual-targeting CAR T cells experienced late relapses (between 60-80 days following initial tumor clearance), all mice (n=5) receiving bbT369 were fully protected from late relapses (up to day 104 of follow-up). Collectively, the data support a first-in-human trial for bbT369 to evaluate initial safety and efficacy in NHL patients.

Citation Format: Michael Certo, Christopher Baldeviano, Sharlene Adams, Martin Asimis, Alexander Astrakhan, Andy Chavkin, Maria L. Cabral, Jimmy Chu, Marie Debrue, Devina Desai, John Evans, Pinky Htun, Amanda Iniguez, Jordan Jarjour, Carl Johnson, Harini Kantamneni, Sema Kurtulus, Michael Magee, Unja Martin, Seamus McKenney, Sara Miller, Prashant Nambiar, Vinh Khang Nguyen, Mauris Nnamani, Jen Obrigewitch, Lisa Pechilis, Molly Perkins, Christopher Petersen, Jason Pinger, Cindy Rogers, Nick Rouillard, Kendal Sanson, Emily Thompson, Collin Walter, Roslyn Yi, Sarah Voytek, Philip Gregory. bbT369, a dual-targeted and CBLB gene-edited autologous CART product, demonstrates anti-lymphoma activity in preclinical mouse models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 581.

Evaluating acceptability and feasibility of a mobile health intervention to improve self-efficacy in prescription opioid tapering in patients with chronic pain: protocol for a pilot randomised, single-blind, controlled trial

INTRODUCTION

Opioid medications are no longer recommended as long-term therapy for chronic non-cancer pain, and many patients are advised to reduce or discontinue opioid medications. Many patients report difficulties in tapering opioid medications, necessitating supporting interventions. This protocol describes a pilot randomised controlled trial (RCT) to investigate the acceptability, feasibility and potential efficacy of a mobile health intervention to improve the opioid tapering self-efficacy of patients with chronic non-cancer pain.

METHODS AND ANALYSIS

The trial will be a single-blind (clinician, data collector and statistician-blinded) pilot RCT with two parallel arms. Forty adult patients with chronic non-cancer pain who are voluntarily reducing their prescribed opioid medications under medical guidance will be recruited from two tertiary pain clinics (Start date 25 August 2021). Participants will be randomly assigned to an intervention or control group. Both groups will receive usual care, including multidisciplinary pain management. In addition to usual care, the intervention group will receive a short informational and testimonial video about opioid tapering and will receive two specifically text messages per day for 28 days. The intervention is codesigned with patients and clinicians to provide evidence-based informational, motivational and emotional support to patients with chronic pain to taper opioid medications. Feasibility of the intervention and a future definitive RCT will be evaluated by measuring patient acceptability, delivery of the intervention, rates and reasons of exclusions and drop-outs, completion rates and missing data in the study questionnaires, and obtaining estimates for sample size determination. Potential efficacy will be evaluated by comparing changes in opioid tapering self-efficacy between the two groups.

ETHICS AND DISSEMINATION

The study protocol was reviewed and approved by the Northern Sydney Local Health District (Australia). Study results will be published in peer-reviewed journals and presented at scientific and professional meetings.

TRIAL REGISTRATION NUMBER

ACTRN12621000795897.

Random Unitary Representations of Surface Groups I: Asymptotic Expansions

In this paper, we study random representations of fundamental groups of surfaces into special unitary groups. The random model we use is based on a symplectic form on moduli space due to Atiyah, Bott and Goldman. Let Σ g denote a topological surface of genus g ≥ 2 . We establish the existence of a large n asymptotic expansion, to any fixed order, for the expected value of the trace of any fixed element of π 1 ( Σ g ) under a random representation of π 1 ( Σ g ) into SU ( n ) . Each such expected value involves a contribution from all irreducible representations of SU ( n ) . The main technical contribution of the paper is effective analytic control of the entire contribution from irreducible representations outside finite sets of carefully chosen rational families of representations.

464 ESCALATION DURING COVID-19

Introduction

During the first surge of COVID-19 it was well recognised that early identification of a plan for escalation in the event of deterioration for each patient was vital. If no decision is documented it results in junior staff frequently making decisions regarding escalation in the out of hours period. This leads to patients, or family members, having these conversations with a doctor they may never have met before. My aim was to improve the documentation of escalation plans in all patients within the first 24 hrs of admission.

Method

Baseline data was collected in September 2019 with further samples in April 2020 and August 2020. Patient medical notes were reviewed to identify if an escalation plan had been made during the period from admission to post take ward round. A COVID admission pathway document was introduced with a specific section on Clinical Frailty Score and Escalation plan between the baseline and April 2020 data.

Results

Baseline data showed that only 12.8% of medical patients had a documented escalation plan within the first 24 hrs of admission to hospital. During the first surge in April 2020 this number had improved to 47% following introduction of the COVID-19 admission pathway. This included 100% of patients admitted to respiratory wards. Unfortunately when reassessed in August 2020, this number had fallen to 16%.

Conclusion

Introduction of clinical frailty scoring and an area specifically to document escalation discussions resulted in a marked improvement. Heightened awareness of rapid deterioration of patients during the first surge almost certainly played a role in this. Unfortunately this was not sustained once staff discontinued the use of COVID-19 admission document. Moving forward we will incorporate these sections into the medical and surgical admissions pathways in the hope it produces similar results.

Tuberculosis and diabetes in low and moderate tuberculosis incidence countries

In countries with low and moderate incidence of tuberculosis (TB), the disease tends to concentrate in specific high-risk populations such as people with diabetes mellitus (DM). We review the updated evidence on the association between 1) DM and active TB, and 2) DM and latent tuberculous infection (LTBI), and 3) we summarize the findings on the population-level impact of DM on TB epidemiology, with particular focus on low- and moderate-incidence settings. We conducted an updated review of studies on DM and active TB, and found 11 more cohort studies published after the previous systematic review from 2008. The updated pooled relative risk (RR) (2.03, 95%CI 1.62-2.55) of all the studies was substantially lower than the three-fold risk increase in the previous review. Substantial heterogeneity of RR across studies was found. Possible reasons for such heterogeneity include different levels of residual confounding, the effect of modification by age, and different levels of glycemic control in the population. In a recently published systematic review on DM and LTBI, one cohort study and 12 cross-sectional studies were identified. The results from cross-sectional studies suggest a significant but modestly increased risk of LTBI among patients with DM (pooled odds ratio 1.18, 95%CI 1.06-1.30). We reviewed evidence on the population-level impact of DM on TB epidemiology in studies using population-attributable fraction analysis and infectious disease modelling. Those studies revealed that DM accounted for a substantial TB burden in low- and moderate-incidence countries. Finally, we discussed the complex association of obesity, DM and TB risk and the impact of the global obesity pandemic on TB epidemiology.

81 A Review of the Referrals to a Daily TIA Service and Subsequent Specialist Diagnosis

Background

Current guidelines highlight the need for all patients experiencing transient ischaemic attacks (TIA) within the previous 7 days to be seen by a specialist service within 24 hours. (RCP National Clinical Guideline for Stroke 2016) Risk stratification tools are no longer recommended.(Lavallee 2007;Wardlaw, 2014) We reviewed the referrals to such a service to assess the proportion of patients who received a diagnosis of TIA and the time taken for assessment.

Methods

We used a retrospective review of 131 patients coded under the daily TIA clinic in 2018 and analysed the clinic letter from the attendance. We assessed the time taken from referral to clinic review and the percentage of patients diagnosed with TIA by the specialist service.

Results

Of 131 patients seen only 33.6% were diagnosed TIA by the stroke specialist team. Other frequently seen diagnoses were migraine (22.9%), presyncope (12.2%), transient global amnesia (4.6%). ‘Other’ diagnoses such as peripheral nerve palsy, cervical root impingement and delirium made up the remainder. Referrals from the emergency department only received TIA diagnosis in 25.3%, GP referrals (34.9%) and eye casualty (83.3%).

The time from referral to review was a mean of 2.45 days. The patients diagnosed with TIA were seen with average of 2.14 days, non TIAs were 2.6 days.

Conclusion

Evidence shows that patients suffering TIA should be seen urgently within 24hrs. The degree of non TIA symptoms being reviewed risks these services being overrun. A review of our service has shown that the average time of referral to review is longer than desired, however only a third of patients seen were felt to have a TIA. Unless there is a change in the standard of referral it will continue to be difficult to see all true TIAs within 24hrs. This will require further education for our colleagues and a more robust triaging system.

Scintigraphy in laryngopharyngeal and gastroesophageal reflux disease: A definitive diagnostic test?

AIM: To investigate the utility of scintigraphic studies in predicting response to laparoscopic fundoplication (LF) for chronic laryngopharyngeal reflux symptoms.

METHODS: Patients with upper aero-digestive symptoms that remained undiagnosed after a period of 2 mo were studied with conventional pH and manometric studies. Patients mainly complained of cough, sore throat, dysphonia and globus. These patients were imaged after ingestion of 99m-technetium diethylene triamine pentaacetic acid. Studies were quantified with time activity curves over the pharynx, upper and lower oesophagus and background. Late studies of the lungs were obtained for aspiration. Patients underwent LF with post-operative review at 3 mo after surgery.

RESULTS: Thirty four patients (20 F, 14 M) with an average age of 57 years and average duration of symptoms of 4.8 years were studied. Twenty four hour pH and manometry studies were abnormal in all patients. On scintigraphy, 27/34 patients demonstrated pharyngeal contamination and a rising or flat pharyngeal curve. Lung aspiration was evident in 50% of patients. There was evidence of pulmonary aspiration in 17 of 34 patients in the delayed study (50%). Pharyngeal contamination was found in 27 patients. All patients with aspiration showed pharyngeal contamination. In the 17 patients with aspiration, graphical time activity curve showed rising activity in the pharynx in 9 patients and a flat curve in 8 patients. In those 17 patients without pulmonary aspiration, 29% (5 patients) had either a rising or flat pharyngeal graph. A rising or flat curve predicted aspiration with a positive predictive value of 77% and a negative predictive value of 100%. Over 90% of patients reported a satisfactory symptomatic response to LF with an acceptable side-effect profile.

CONCLUSION: Scintigraphic reflux studies offer a good screening tool for pharyngeal contamination and aspiration in patients with gastroesophageal reflux disease.

A novel CDX2 isoform regulates alternative splicing

Gene expression is a dynamic and coordinated process coupling transcription with pre-mRNA processing. This regulation enables tissue-specific transcription factors to induce expression of specific transcripts that are subsequently amplified by alternative splicing allowing for increased proteome complexity and functional diversity. The intestine-specific transcription factor CDX2 regulates development and maintenance of the intestinal epithelium by inducing expression of genes characteristic of the mature enterocyte phenotype. Here, sequence analysis of CDX2 mRNA from colonic mucosa-derived tissues revealed an alternatively spliced transcript (CDX2/AS) that encodes a protein with a truncated homeodomain and a novel carboxy-terminal domain enriched in serine and arginine residues (RS domain). CDX2 and CDX2/AS exhibited distinct nuclear expression patterns with minimal areas of co-localization. CDX2/AS did not activate the CDX2-dependent promoter of guanylyl cyclase C nor inhibit transcriptional activity of CDX2. Unlike CDX2, CDX2/AS co-localized with the putative splicing factors ASF/SF2 and SC35. CDX2/AS altered splicing patterns of CD44v5 and Tra2-β1 minigenes in Lovo colon cancer cells independent of CDX2 expression. These data demonstrate unique dual functions of the CDX2 gene enabling it to regulate gene expression through both transcription (CDX2) and pre-mRNA processing (CDX2/AS).

Obesity by choice revisited: effects of food availability, flavor variety and nutrient composition on energy intake

Recent work suggested that the energy intake and weight gain of rats maintained on chow and 32% sucrose solution could be increased by simply offering more sources of sucrose [Tordoff M.G. Obesity by choice: the powerful influence of nutrient availability on nutrient intake. Am J Physiol 2002;282:R1536-R1539.]. In Experiment 1 this procedure was replicated but the effect was not: rats given one bottle of sucrose and five bottles of water consumed as much sucrose as those given five bottles of sucrose and one of water. Adding different flavors to the sucrose did not increase intakes further in Experiment 2. The relative potency of sucrose and other optional foods was studied in Experiment 3. Sucrose solution stimulated more overeating and weight gain than fat (vegetable shortening), and offering both sucrose and shortening did not generate further increases in energy intake. Finally, foods commonly used to produce overeating and weight gain were compared. Sucrose was less effective than a high-fat milk diet, and offering cookies in addition to the milk did not increase energy intake further. The nature of optional foods (nutrient composition and physical form) was markedly more important than the number of food sources available to the animals, and is a better contender as the reason for "obesity by choice".

Evaluation of Soluble CD30 as an Immunologic Marker in Heart Transplant Recipients

CD30 is an immunologic molecule that belongs to the TNF-R superfamily. CD30 serves as a T-cell signal transducing molecule that is expressed by a subset of activated T lymphocytes, CD45RO+ memory T cells. Augmentation of soluble CD30 during kidney transplant rejection has been reported. Our study sought to determine whether the level of sCD30 prior to heart transplant could categorize patients into high versus low immunologic risk for a poor outcome. A significant correlation was observed between high levels of soluble CD30 and a reduced incidence of infection. None of the 35 patients with high pretransplant levels of sCD30 level (>90 U/mL) developed infections posttransplantation. However, 9 of 65 patients who had low levels of sCD30 (<90 U/mL) developed infections posttransplantation (P < .02). No remarkable differences were noted among the other clinical parameters. The results also showed that the high-definition flow-bead (HDB) assay detected both weak and strong class I and class II HLA antibodies, some of which (weak class II HLA Abs) were undetectable by the anti-human globulin cytotoxicity method. In addition, more antibody specificities were detected by HDB. In conclusion, we have observed that high levels of sCD30 prior to heart transplant may be associated with greater immunologic ability and therefore produce a protective effect on the development of infection post heart transplant. We have also shown that the HDB assay is superior to the visual cytotoxicity method to detect HLA antibodies, especially those to class II HLA antigens.

Degenerative spondylolysis: a concise report of scintigraphic observations

OBJECTIVES

Spondylolysis is traditionally thought to be a diagnosis of adolescence and childhood, and is ascribed to mechanical stress through the immature pars interarticularis. Over the last 4 yr we have noted a presentation of spondylolysis in association with hypertrophic zygapophyseal joint disease in the lumbar spine in an older age group.

METHODS

Records of 94 patients presenting with low back pain were examined. A pattern of intense zygapophyseal joint uptake in association with extended uptake in the pars interarticularis was ascribed as degenerative spondylolysis.

RESULTS

The ages of the 94 cases ranged from 33 to 80 yr (mean 64 yr). There were 53 males and 41 females. In the group with degenerative spondylolysis the mean age was 72 yr, with four females and two males. None of these six patients gave a history of childhood spinal disease or back pain and all were relatively inactive in terms of current participation in sport. All cases of spondylolysis were confirmed by computed tomography scanning.

CONCLUSION

The finding of hypertrophic zygapophyseal joint disease in association with spondylolysis is easily recognized by scintigraphic tomographic imaging.

The role of left ventricular hypertrophy and diabetes in the presence of transient ischemic dilation of the left ventricle on myocardial perfusion SPECT images

Transient ischemic dilation of the left ventricle found on SPECT myocardial perfusion imaging (MPI) is an accepted marker of severe and extensive coronary artery disease (CAD) and poor prognosis. The influence of other clinical variables on the incidence of transient ischemic dilation is less certain. The aim of this study was to investigate clinical factors that may influence the incidence of transient ischemic dilation. In particular, we looked at factors that may independently affect subendocardial perfusion, such as left ventricular hypertrophy (LVH) and diabetes.

METHODS

MPI studies of 103 consecutive patients who had undergone recent coronary angiography (< or =6 mo) and transthoracic echocardiography within a year of stress electrocardiography-gated MPI were retrospectively analyzed. Transient ischemic dilation was assessed quantitatively using a software program. A ratio cutoff of > or =1.22 was considered to represent transient ischemic dilation. Summed stress score and summed difference score (ischemia score) were determined using the standard 17-segment 5-point scoring system to quantify myocardial ischemia. LVH was defined as a left ventricular wall thickness of >11 mm on M-mode echocardiography. Severe CAD was defined as severe stenosis (> or =90%) of either the left anterior descending artery or both the right coronary and lateral circumflex arteries.

RESULTS

Nineteen (18%) of the 103 patients had transient ischemic dilation, 19 (18%) had LVH, and 23 (22%) were diabetic. A high percentage had severe CAD (46/103 [45%]), whereas 57 of 103 (55%) had less severe CAD (30/103 [29%]) or nonsignificant CAD (26/103 [25%]). Severe CAD (P < 0.001), diabetes (P < 0.0001), LVH (P < 0.003), and the ischemia score (P < 0.023) were independent predictors of transient ischemic dilation by multivariate logistic regression. In patients with severe CAD, the effect of LVH on the incidence of transient ischemic dilation was additive, increasing the incidence from 21% (8/38) without LVH to 75% (6/8) with LVH (P < 0.006). Likewise, with severe CAD, the incidence of transient ischemic dilation rose from 21% (7/33) in patients without diabetes to 54% (7/13) in those with diabetes (P < 0.04).

CONCLUSION

The presence of transient ischemic dilation on myocardial perfusion SPECT is associated with the presence of severe CAD, but this association is modified by the presence of LVH and diabetes.

E-Learning Lifecycles:How Communities and Context can affect E-learning Specifications and Tool Design

The development of a large body of e-learning specifications, such as IMS and SCORM, has led to the proposal for a new way to facilitate content workflow. This involves the movement of educational digital content and the knowledge of pedagogical communities into an online space. Several projects have looked at the theoretical structure of these specifications. They implemented a series of tools in order to examine and research the issues around the actual usage of these specifications. The CAREO, ALOHA and ALOHA 2 projects were designed to expose both individual users and whole institutions to these ideas. Initial research into the result of those interactions indicates that there is some utility in the adoption of e-learning specifications. The future success of them will depend on their ability to adapt and meet the needs of the educational community as they begin to adopt, use and evolve the way they use the specifications and the tools created around them.

Physician empathy: definition, components, measurement, and relationship to gender and specialty

OBJECTIVE

There is a dearth of empirical research on physician empathy despite its mediating role in patient-physician relationships and clinical outcomes. This study was designed to investigate the components of physician empathy, its measurement properties, and group differences in empathy scores.

METHOD

A revised version of the Jefferson Scale of Physician Empathy (with 20 Likert-type items) was mailed to 1,007 physicians affiliated with the Jefferson Health System in the greater Philadelphia region; 704 (70%) responded. Construct validity, reliability of the empathy scale, and the differences on mean empathy scores by physicians' gender and specialty were examined.

RESULTS

Three meaningful factors emerged (perspective taking, compassionate care, and standing in the patient's shoes) to provide support for the construct validity of the empathy scale that was also found to be internally consistent with relatively stable scores over time. Women scored higher than men to a degree that was nearly significant. With control for gender, psychiatrists scored a mean empathy rating that was significantly higher than that of physicians specializing in anesthesiology, orthopedic surgery, neurosurgery, radiology, cardiovascular surgery, obstetrics and gynecology, and general surgery. No significant difference was observed on empathy scores among physicians specializing in psychiatry, internal medicine, pediatrics, emergency medicine, and family medicine.

CONCLUSIONS

Empathy is a multidimensional concept that varies among physicians and can be measured with a psychometrically sound tool. Implications for specialty selection and career counseling are discussed.

Empathy in medical students as related to academic performance, clinical competence and gender

CONTEXT

Empathy is a major component of a satisfactory doctor-patient relationship and the cultivation of empathy is a learning objective proposed by the Association of American Medical Colleges (AAMC) for all American medical schools. Therefore, it is important to address the measurement of empathy, its development and its correlates in medical schools.

OBJECTIVES

We designed this study to test two hypotheses: firstly, that medical students with higher empathy scores would obtain higher ratings of clinical competence in core clinical clerkships; and secondly, that women would obtain higher empathy scores than men.

MATERIALS AND SUBJECTS

A 20-item empathy scale developed by the authors (Jefferson Scale of Physician Empathy) was completed by 371 third-year medical students (198 men, 173 women).

METHODS

Associations between empathy scores and ratings of clinical competence in six core clerkships, gender, and performance on objective examinations were studied by using t-test, analysis of variance, chi-square and correlation coefficients.

RESULTS

Both research hypotheses were confirmed. Empathy scores were associated with ratings of clinical competence and gender, but not with performance in objective examinations such as the Medical College Admission Test (MCAT), and Steps 1 and 2 of the US Medical Licensing Examinations (USMLE).

CONCLUSIONS

Empathy scores are associated with ratings of clinical competence and gender. The operational measure of empathy used in this study provides opportunities to further examine educational and clinical correlates of empathy, as well as stability and changes in empathy at different stages of undergraduate and graduate medical education.

Impact of health care system on physicians' discontent

This study was designed to investigate the impact of physicians' perceptions of the health care system on their discontent with their profession. By using a random digit dialing technique, a structured telephone interview was conducted with 401 generalist physicians (343 men, 56 women) who were practicing medicine at least for five years and were younger than 65 years. Physicians' willingness to choose medicine again was correlated with their perceptions of different aspects of the health care system. Of the total participants, 288 (72 percent) indicated that they would choose medicine again, 91 (23 percent) would not choose medicine, and 22 (5 percent) were not sure. Results of the step-wise logistic regression showed that after adjustment for physicians' gender and age, those who would not choose medicine again were more than twice as likely as other physicians who would choose medicine to believe that the health care environment will deteriorate more in the future (odds ratio = 2.1, p < .01), were less than half as likely to believe that physicians nowadays share more responsibilities with other health care professionals (odds ratio = .42, p < .01), and were less than half as likely to confirm that patients understand their health insurance better than before (odds ratio = .46, p < .01). Findings suggest that physicians' discontent can be predicted by their negative perceptions of the health care environment. Findings have implications for improving the quality of professional and personal life of the physician, thus improving the quality of care and satisfaction of the patient.

Left mini-thoracotomy for beating heart bypass grafting: a safe alternative to high-risk intervention for selected grafting of the circumflex artery distribution

BACKGROUND

Progression of disease and bypass graft attrition results in a population of patients who require repeated coronary interventions. Frequently, these patients have patent internal mammary artery grafts and require isolated intervention to the circumflex distribution. As an alternative to high-risk repeated sternotomy and conventional bypass surgery or catheter-based intervention, the circumflex marginal vessels may be approached by thoracotomy. We reviewed our experience in revascularizing the circumflex distribution with off-pump techniques via left mini-thoracotomy.

METHODS AND RESULTS

Thirty-two patients underwent off-pump bypass grafting of the circumflex vessels via thoracotomy from December 1995 to April 2000. Twenty-seven patients presented with circumflex disease after having previous bypass grafting. Five patients, who presented with circumflex disease and either nondiseased or ungraftable disease in their other arteries, were revascularized as a primary procedure. There was no observed mortality. Seven patients (22%) required inotropes on leaving the operating room, and 3 patients (9.4%) received transfusion of packed red blood cells. There was 1 reoperation for bleeding and 1 patient with a postoperative neurological deficit. There were no perioperative myocardial infarctions. The average length of stay was 4.8 days from time of surgery to discharge.

CONCLUSIONS

Off-pump grafting via thoracotomy provides a safe and effective alternative approach for patients requiring limited revascularization. Potential cardiac injury and danger to viable grafts from repeated sternotomy is minimized, and manipulation of the diseased ascending aorta is avoided. Morbidity, hospital length of stay, and cost are less than for conventional repeated coronary bypass surgery.

A study of U.S. orchards to identify potential sources of Escherichia coli O157:H7

The association of unpasteurized apple cider with Escherichia coli O157:H7 foodborne illness has led to increased interest in potential reservoirs of this pathogen in the orchard. Fourteen U.S. orchards were surveyed in autumn 1999 to determine the incidence and prevalence of E. coli O157:H7, E. coli, total aerobic microflora, and yeasts and molds. Fruit samples (n = 63) (eight apple and two pear varieties) and soil, water, and fecal samples were collected. Samples were plated on (i) tryptic soy agar for total mesophilic aerobic count, (ii) E. coli and coliform Petrifilm for total coliforms and E. coli, and (iii) yeast and mold Petrifilm. Samples positive for coliforms and E. coli were enriched and tested for E. coli O157:H7. Fruit was also tested for internalization of microflora by aseptically removing the core, stem, and calyx areas, and the individual sections were assessed for the categories of microflora listed above. E. coli was detected in soil and water and in 6% of fruit samples (three pear samples and one apple sample), generally collected from areas previously designated as high risk in this study. However, no E. coli O157:H7 was found. Coliforms were found in 74% of fruit samples and were internalized in the cores of 40% of fruit tested. Yeasts and molds were internalized in 96.7% of samples and aerobic bacteria in 89.6%. E. coli was not found to be internalized. Total aerobic counts and total coliforms were higher in dropped and damaged fruit (P < 0.05). Findings suggest that dropped or damaged fruit should not be included in fruit designated for the production of unpasteurized juice or for the fresh or fresh-cut market. In addition, orchards should be located away from potential sources of contamination, such as pastures.

Clinical significance of the arthroscopic drive-through sign in shoulder surgery

PURPOSE

During arthroscopy of the shoulder, the ability to pass the arthroscope easily between the humeral head and the glenoid at the level of the anterior band of the inferior glenohumeral ligament is considered a positive drive-through sign. The drive-through sign has been considered diagnostic of shoulder instability and has been associated with shoulder laxity and with SLAP lesions. The goal of this study was to examine the prevalence of the drive-through sign in patients undergoing shoulder arthroscopy and to determine its relationship to shoulder instability, shoulder laxity, and to SLAP lesions.

TYPE OF STUDY

Case series.

METHODS

We prospectively studied 339 patients undergoing arthroscopy of the shoulder for a variety of diagnosis from 1992 to 1998. The drive-through sign was performed with the patients in a lateral decubitus position and under general anesthesia. The drive-through sign was correlated with preoperative physical findings, intraoperative laxity testing, and with intra-articular pathology at the time of arthroscopy.

RESULTS

The arthroscopic evaluation showed that drive-through sign was positive in 234 (69%) shoulders. For the diagnosis of instability, the drive-through sign had a sensitivity of 92%, a specificity of 37. 6%, a positive predictive value of 29.9%, a negative predictive value of 94.2%, and an overall accuracy of 49%. There was an association between the drive-through sign and increasing shoulder laxity, but not with SLAP lesions.

CONCLUSIONS

This study shows that a positive drive-through sign is not specific for shoulder instability but is associated with shoulder laxity. This arthroscopic sign should be incorporated with other factors when considering the diagnosis of instability.

A comparison of the personality profiles of internal medicine residents, physician role models, and the general population

PURPOSE

To compare personality profiles of internal medicine residents with those of the general population and positive role models in medicine.

METHOD

A widely used personality inventory, NEO PI-R, which measures five major personality factors and 30 important personality facets, was administered in 1998 to 104 physicians in internal medicine residency and earlier to a nationwide sample of 188 physicians selected as positive role models in medicine.

RESULTS

The internal medicine residents, compared with the general population, were more likely to be attentive, to have deeper intellectual curiosity, to have higher aspiration levels, to have more vivid imaginations, to be more receptive to their emotions, to be interested in mental stimulation, and to think carefully before acting. The residents, compared with role models in medicine, were less eager to face challenges, less able to control their impulses, less able to cope with adversity, less easygoing, and less relaxed, but were more likely to crave excitement.

CONCLUSION

Internal medicine residents and positive role models in medicine have some distinct personal qualities. Understanding the qualities of successful physicians can be helpful in career counseling of medical students and young physicians.

Single-photon emission tomography of a computerised model of pulmonary embolism

Planar pulmonary scintigraphy is currently the standard investigation for the diagnosis of pulmonary embolism. There are a number of problems with the technique, particularly in patients with an intermediate scan report under the PIOPED criteria. The technique is also under threat from the increasing use of spiral CT angiography. A putative improvement may be gained by use of tomography. The incremental value of tomography over planar studies was therefore evaluated in a virtual model of pulmonary scintigraphy. A model of the segmental anatomy of the lungs was developed from computed tomography, cadaveric human lungs and available anatomical texts. Counts were generated within the phantom by Monte Carlo simulation of photon emission. Eighteen single segmental lesions were interspersed with 47 subsegmental defects and displayed on an Icon reporting station. These were presented in the transaxial, sagittal and coronal planes to four experienced reporters to obtain assessment of defect size. Planar studies of the same defects were displayed to the same observers in the standard eight views with a normal study for comparison. With planar studies, the accuracy of estimation of defect size was 51% compared with 97% using tomographic studies. Defects in the medial basal segment of the right lower lobe were not identified in planar studies but were easily seen by all observers in the tomographic study. It is concluded that there is marked improvement in the accuracy of determination of defect size for tomographic studies over the planar equivalents. This is especially important in the lung bases, the most common reported site of pulmonary emboli. Tomography permits visualisation of defects in the medial basal segment of the right lung, which are not seen in planar studies.

Oral use of interferon-alpha stimulates ISG-15 transcription and production by human buccal epithelial cells

ISG-15 is a 15-kDa protein encoded by an interferon (IFN)-stimulated gene (ISG), which is transcriptionally regulated by IFN-alpha and IFN-beta. Considered as part of the cytokine network, ISG-15 has the potential to amplify the immunomodulatory effects of these IFNs by enhancing IFN-gamma production, natural killer cell proliferation, and lymphokine-alphactivated killer cell cytotoxicity. To understand better the mechanism(s) of action of orally administered IFN-alpha, we have studied the effect of IFN-alpha on ISG-15 gene expression by human buccal epithelial cells (BEC). For in vitro studies, ISG-15 mRNA and protein levels were measured in BEC incubated for 0.5, 2, and 9 h with 100 or 1,000 IU/ml of human lymphoblastoid IFN-alpha. For in vivo studies, ISG-15 mRNA was measured in BEC samples collected at baseline, and 0.5, 2, and 9 h after 5-20 min of oral rinsing with 10 ml of IFN-alpha (1,000 IU/ml). ISG-15 mRNA was measured by reverse transcriptase polymerase chain reaction (RT-PCR), and ISG-15 protein production by Western Blot analysis. IFN-alpha augmented BEC ISG-15 gene expression in a concentration dependent manner both in vivo and in vitro. We conclude that orally administered IFN-alpha exerts its immunomodulatory effects in humans in part by upregulating the production of ISG-15 by BEC, thereby enhancing the immune reactivity of mucosa-associated lymphocytes.

Phase I-II evaluation of rapid sequence tandem high-dose melphalan with peripheral blood stem cell support in patients with multiple myeloma

This study was designed to determine the maximum tolerated dose (MTD) of high-dose melphalan (HDM), with peripheral blood stem cell support, that could be given twice within 90 days to patients with multiple myeloma. Twenty patients received tandem HDM at 160, 180 or 200 mg/m2 and a total of 55 were treated at the estimated MTD of 200 mg/m2. Seventeen of 55 (31%) did not receive cycle 2; six because of low CD34+ cell yields, three because of severe (n = 1) or fatal toxicities (n = 2) and eight for other reasons. The median interval between doses for 38 patients was 70 days (range 41-225). Three of 55 patients (5%) died of treatment-related causes. In patients completing two cycles of HDM, at any dose level, the complete remission rate improved from 15% following cycle 1 to 55% following cycle 2. The probabilities of survival, event-free survival and relapse or progression at 18 months for the 55 patients treated at the MTD were 0.84, 0.76 and 0.20, respectively, with a median follow-up of 19 months (range 9-36) from mobilization chemotherapy. It was concluded that two cycles of HDM, 200 mg/m2, could be administered to approximately 70% of patients under the age of 66 with multiple myeloma in a median interval of 70 days, with improvement in CR rates.

Enhanced accuracy and reproducibility in reporting of lung scintigrams by a segmental reference chart

The diagnostic probability of pulmonary embolic disease is based on the recognition of unmatched segmental perfusion defects. Although interobserver and intraobserver reproducibility have been studied, accuracy has been an elusive goal due to the lack of a gold standard. We investigated the accuracy and reproducibility of reporting in a virtual scintigraphic model of the lungs, with and without the use of a lung segmental reference chart.

METHODS

A Monte Carlo package was used to model lung scintigraphy from a digital phantom of the human lungs. An ideal lung segmental reference chart was created from the phantom. Five experienced nuclear medicine physicians reported a set of all possible defects involving 100% of a segment, without and with the chart. A further set of defects involving 45%-55% of a segment in the lower lobes was investigated using the chart.

RESULTS

There was a significant improvement in accuracy (from 48% to 72%) and intraobserver agreement (from 61% to 77%) with the chart. The accuracy of reporting defects in the upper and middle lobes was consistently better than that in the lower lobes. There was no significant difference between the accuracy of reporting large defects and that of reporting moderate defects in the lower lobes.

CONCLUSION

The lung segmental reference chart significantly improves both the accuracy and reproducibility of reporting lung scintigrams; however, although reporting in the lung bases is improved, absolute accuracy is substantially less than that in the upper and middle lobes. This emphasizes the need for caution because the lung bases are the most common site of embolic disease.

Personality profiles of male and female positive role models in medicine

This study was designed to investigate the personality profile of positive role models in medicine. Participants were a national sample of 188 physicians (164 men, 24 women) who had been nominated by the chief executive officers of their institutions as positive role models and who completed the Revised NEO Personality Inventory. Compared to the general population, these 188 male and female positive role models in medicine scored higher on Conscientious factor, and on Achievement Striving, Activity, Competence, Dutifulness, Trust, Assertiveness, and Altruism facets, but they scored lower on the Vulnerability facet than the general population. In addition, the male role models scored significantly higher than men in the general population on the Agreeableness factor, and the female role models obtained significantly higher scores than the population norms on Extraversion and Openness factors, and on Feelings, Ideas, Positive Emotions, Values, Warmth, Aesthetics, and Fantasy facets. The female role models scored far below their sex-related norms on Neuroticism factor and on Angry Hostility facet. Comparisons between the male and female role models showed that the female role models scored higher on the Openness factor, and on the Feelings, Positive Emotions, Aesthetics, and Fantasy facets of personality. Implications in medical education and in explaining, assessing, and improving the qualities that contribute to professional success and in promoting the concept of "positive medicine" are discussed.

Variability of perceived defect size in virtual lung scintigraphy

The diagnosis of pulmonary embolism is based on the presence of mismatched segmental or subsegmental defects. An important axiom is the classification of defect sizes into small, moderate and large. Little information about the recognition and classification of such defects has been published. We undertook a study of the perception of defect size using a model of the virtual scintigraphic anatomy of the lungs to address this issue.

METHODS

Segmental anatomy of the lungs was modeled with CT, cadaveric lungs and standard anatomical tests. The emission, scatter and attenuation of photons were modeled within these virtual lungs and the surrounding tissues. Single segmental lesions, each 100% of a segment, were created in eight projections and submitted for blinded reporting by four experienced nuclear medicine physicians to obtain their assessment of the size of each defect on two occasions.

RESULTS

Of the 144 defects submitted for reporting, 15% were reported as <25% of a segment, 35% were reported as 25%-75% and 50% were reported as 75%-100%. The accuracy of each reporter and the intraobserver agreement were calculated; the weighted kappa value ranged from 0.34 to 0.60. The segmental defects that were most likely to be underestimated in size were in the right lower lobe.

CONCLUSION

It is clear that segmental defect sizes were underestimated, particularly in the right lower lobe. Although the intraobserver agreement in reporting was fair, the accuracy of estimation was only 50%. The variability and inaccuracy might be reduced by the use of a guide to segmental anatomy.

Optimization of the scintigraphic segmental anatomy of the lungs

Accurate and reproducible reporting of lung scintigraphy is predicated on a sound knowledge of the segmental anatomy of the lungs. A limited amount of hard data exists about the true segmental anatomy of the lungs. A virtual model of human lungs was created using a CT-based dataset and a Monte Carlo simulation technique to examine the optimal projections for the visualization of each segment in the lungs.

METHODS

Segmental anatomy of the lungs was modeled using CT, cadaveric lungs and standard anatomical texts. The emission, scatter and attenuation of photons was modeled within these virtual lungs and the surrounding tissues. Single segmental lesions were created in eight projections and submitted for blinded reporting to four experienced nuclear medicine physicians to obtain the best views for each segment.

RESULTS

The anterior and posterior oblique projections yielded the best views for 10 of 18 segments, with the laterals contributing four views, the anterior contributing two views and the posterior contributing one view. The majority of basal segments (six of nine) were best seen in the anterior and posterior oblique projections.

CONCLUSION

This model overcomes the major problems associated with experimentation in the normal human and has the potential to provide answers to the major problems of scatter, attenuation and "shine-through" in lung scintigraphy.