The Legionella pneumophila effector DenR hijacks the host NRas proto-oncoprotein to downregulate MAPK signaling

Small GTPases of the Ras subfamily are best known for their role as proto-oncoproteins, while their function during microbial infection has remained elusive. Here, we show that Legionella pneumophila hijacks the small GTPase NRas to the Legionella-containing vacuole (LCV) surface. A CRISPR interference screen identifies a single L. pneumophila effector, DenR (Lpg1909), required for this process. Recruitment is specific for NRas, while its homologs KRas and HRas are excluded from LCVs. The C-terminal hypervariable tail of NRas is sufficient for recruitment, and interference with either NRas farnesylation or S-acylation sites abrogates recruitment. Intriguingly, we detect markers of active NRas signaling on the LCV, suggesting it acts as a signaling platform. Subsequent phosphoproteomics analyses show that DenR rewires the host NRas signaling landscape, including dampening of the canonical mitogen-activated protein kinase pathway. These results provide evidence for L. pneumophila targeting NRas and suggest a link between NRas GTPase signaling and microbial infection.

A25 MEASURING THE OBSERVER (HAWTHORNE) EFFECT ON ADENOMA DETECTION RATES: A CASE-CONTROL RETROSPECTIVE STUDY

Background

The effectiveness of colonoscopy screening to prevent colorectal cancer (CRC) is directly linked to its procedural quality. An independent observer (Hawthorne effect) can improve colonoscopy procedural quality metrics, including adenoma detection rate (ADR). However, the results of studies are limited or controversial.

Purpose

We aimed to evaluate the colonoscopy quality metrics in a group of patients undergoing screening or diagnostic colonoscopies under stringent observer conditions.

Method

In a single-center, case–control study, consecutive patients undergoing routine screening or diagnostic colonoscopy were prospectively enrolled. In the case group, all procedural steps and quality metrics were observed and documented, and the procedure was video recorded by an independent research assistant. In the control group, colonoscopies were performed without independent observation. Colonoscopy quality metrics such as polyp, adenoma, serrated lesions, and advanced adenoma detection rates (PDR, ADR, SLDR, AADR), the mean number of adenomas detected per patient (MAP), and the mean number of adenomas and serrated lesions detected per patient (MASP) were compared. The probabilities of increased quality metrics were evaluated through regression analyses weighted by the inversed probability of observation during the procedure.

Result(s)

We included a total of 687 patients (327 cases and 360 controls) in the final analyses. The case group had significantly higher PDRs (62.4% vs. 53.1%) and ADRs (39.4% vs. 28.3%) compared with the control group. The SLDR was also higher in the case group than in the control group, but the difference was not significant (7.3% vs. 4.4%; P = 0.14). The AADR was not significantly increased. After adjusting for potential confounders, the ADR and SLDR were 50% (odds ratio [OR] 1.51; 95%CI 1.05–2.17) and more than twofold (OR 2.17; 95%CI 1.05–4.47) more likely to be higher in the case group than in the control group. The MAP and MASP were significantly increased in the case group compared with the control group (P < 0.001). The regression analyses for both metrics demonstrated the direct and significant association between the Hawthorne effect and elevated MAP/MASP.

Conclusion(s)

The presence of an independent observer documenting colonoscopy quality metrics and video recording the colonoscopy resulted in a significant increase in ADR and other quality metrics. The Hawthorne effect should be considered an alternative strategy to advanced devices to improve colonoscopy quality in routine practice.

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None

Disclosure of Interest

M. Taghiakbari: None Declared, D. Coman: None Declared, M. Takla: None Declared, A. N. Barkun: None Declared, M. Frija-Gruman: None Declared, M. Bouin: None Declared, S. Bouchard: None Declared, E. Deslandres: None Declared, S. Sidani: None Declared, D. von Renteln Grant / Research support from: ERBE, Ventage, Pendopharm, and Pentax, Consultant of: Boston Scientific and Pendopharm

A108 AUTOMATED DETECTION OF ILEOCECAL VALVE, APPENDICEAL ORIFICE, AND POLYP DURING COLONOSCOPY USING A DEEP LEARNING MODEL

Background

Identification and photo-documentation of the ileocecal valve (ICV) and appendiceal orifice (AO) confirm completeness of colonoscopy examinations. We hypothesized that an artificial intelligence (AI)-empowered solution could help us automatically differentiate anatomical landmarks such as AO and ICV from polyps and normal colon mucosa.

Purpose

We aimed to develop and test a deep convolutional neural network (DCNN) model that can automatically identify ICV and AO, and differentiate these landmarks from normal mucosa and colorectal polyps.

Method

We prospectively collected annotated full-length colonoscopy videos of 318 patients undergoing outpatient colonoscopies. We created three non-overlapping training, validation, and test datasets with 25,444 unaltered frames extracted from the colonoscopy videos showing four landmarks/image classes (AO, ICV, normal mucosa, and polyps). For each landmark, we extracted an average of 30 frames for each time of its appearance. All the extracted frames were reviewed and annotated by a team of three clinicians. Using a quality assessment tool, the clinicians examined a total of 86,754 frames (7982 AO, 8374 ICV, 32,971 polyps, and 37,427 normal mucosa) and verified whether or not the frame contained one unique landmark. For this research, all frames were extracted from the white-light colonoscopies, and all narrow-band imaging frames were excluded. A DCNN classification model was developed, validated, and tested in separate datasets of images. The primary outcome was the proportion of patients in whom the AI model could identify both ICV and AO, and differentiate them from polyps and normal mucosa, with an accuracy of detecting both AO and ICV above a threshold of 40% (representing a value in which reliable identification of the landmarks can be assumed without increasing false-positive alerts).

Result(s)

We trained a DCNN AI model on 21,503 unaltered frames extracted from the recorded colonoscopy videos of 272 patients, and validated and tested the model on 1,924 (25 patients) and 2,017 (21 patients) unaltered frames, respectively. We applied a transfer learning technique to fine-tune the model parameters to the endoscopic images using a cross-entropy loss function and back-propagation algorithm. After training and validation, the DCNN model could identify both AO and ICV in 18 out of 21 patients (85.71%), if accuracies were above the threshold of 40%. The accuracy of the model for differentiating AO from normal mucosa, and ICV from normal mucosa were 86.37% (95% CI 84.06% to 88.45%), and 86.44% (95% CI 84.06% to 88.59%), respectively. Furthermore, the accuracy of the model for differentiating polyps from normal mucosa was 88.57% (95% CI 86.60% to 90.33%).

Conclusion(s)

The model can reliably distinguish these anatomical landmarks from normal mucosa and colorectal polyps. It can be implemented into automated colonoscopy report generation, photo-documentation, and quality auditing solutions to improve colonoscopy reporting quality.

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Other

Please indicate your source of funding;

MEDTEQ

Disclosure of Interest

M. Taghiakbari: None Declared, S. Hamidi Ghalehjegh Employee of: Imagia Canexia Health Inc. , E. Jehanno Employee of: Imagia Canexia Health Inc. , T. Berthier Employee of: Imagia Canexia Health Inc. , L. di Jorio Employee of: Imagia Canexia Health Inc. , A. N. Barkun Grant / Research support from: co-awardee in funded research projects with Imagia Canexia Health Inc., Consultant of: Medtronic Inc. and A.I. VALI Inc, E. Deslandres: None Declared, S. Bouchard: None Declared, S. Sidani: None Declared, Y. Bengio: None Declared, D. von Renteln Grant / Research support from: ERBE, Ventage, Pendopharm, and Pentax, Consultant of: Boston Scientific and Pendopharm

Virtual reality-based exposure with applied biofeedback for social anxiety disorder

Introduction

Social Anxiety Disorder (SAD) is considered the most prevalent anxiety disorder with the highest disease burden amongst anxiety disorders. Despite available effective treatment with Cognitive Behavioral Therapy, a majority of individuals with SAD do not seek treatment and many drop out when confronted with elements of exposure. Several studies highlight the many advantages virtual reality exposure holds over in vivo exposure. In this study, we investigate the added effect of real-time biofeedback during virtual reality exposure.

Objectives

The current study is part of a large scale study called VR8. The current study aims to develop and evaluate the feasibility of a VR-biofeedback-intervention for adults with mild to severe social anxiety disorder, before continuing randomized controlled trials.

Methods

Data from semi-structured interviews and surveys will be compared to biodata collected during VR exposure. Participants include a minimum of (n=10) patients and (n=10) clinicians from the Mental Health Services in the Region of Southern Denmark. Surveys include questionnaires used for assessment of anxiety symptoms, usability of technology, and presence in the virtual environment. Collected biodata includes heart rate variability and electrodermal activity. Behavioral markers include eye-gaze. The findings will be analyzed and discussed in a mixed methods design.

Results

The study is ongoing. Preliminary results will be available at presentation.

Conclusions

Successful development and implementation of a biofeedback-informed virtual reality exposure intervention may provide increased reach for patients and individuals who would have otherwise not sought- or dropped out of regular treatment, as well as inform the clinician on how to proceed during virtual exposure.

Conflict of interest

Prof. Stephané Bouchard is consultant to and own equity in Cliniques et Développement In Virtuo, which develops virtual environments, and conflicts of interests are managed according to UQO’s conflict of interests policy; however, Cliniques et Développeme

A119 THE LOCATION-BASED RESECT AND DISCARD STRATEGY FOR DIMINUTIVE COLORECTAL POLYPS: A PROSPECTIVE CLINICAL STUDY

Background

Replacing histopathology evaluation of diminutive polyps with optical polyp diagnosis is considered a cost-effective approach. However, the widespread use of optical diagnosis is limited due to concerns about making incorrect optical diagnoses and the requirements of training, credentialing and auditing of performance.

Aims

This prospective study aimed to evaluate a simplified resect and discard strategy that is not operator dependent.

Methods

The study evaluated a resect and discard strategy that uses anatomical polyp location to classify colon polyps into non-neoplastic or low-risk neoplastic. All rectosigmoid diminutive polyps were considered hyperplastic and all polyps located proximally to the sigmoid colon were considered neoplastic. Surveillance interval assignments based on these a priori assumptions were compared with those based on actual pathology results and optical diagnosis, respectively. The primary outcome was ≥90% agreement with pathology in surveillance interval assignment.

Results

Overall, 1117 patients undergoing complete colonoscopy were included and 482 (43.1%) had at least one diminutive polyp. Surveillance interval agreement between the location-based resect and discard strategy and pathological findings using the 2020 US Multi-Society Task Force guideline was 97.0% (95% CI = 0.96 - 0.98), surpassing the ≥90% benchmark. Optical diagnoses using NICE and Sano classifications reached 89.1% and 90.01% agreement, respectively (p &lt;0.0001), and were inferior to the location-based strategy. The location-based resect and discard strategy allowed a 69.7% (95% CI = 0.67 - 0.72) reduction in pathology examinations compared with 55.3% (95% CI = 0.52 - 0.58) (NICE and Sano) and 41.9% (95% CI = 0.39 - 0.45) (WASP) with optical diagnosis.

Conclusions

The location-based resect and discard strategy achieved very high surveillance interval agreement with pathology-based surveillance interval assignment, surpassing the ≥90% quality benchmark and outperforming optical diagnosis in surveillance interval agreement and the number of pathology examinations avoided.

Funding Agencies

None

Dissecting the expression landscape of genitourinary cancers

573

Background: Genitourinary (GU) cancers include bladder urothelial carcinoma (BCa), prostate cancer, kidney clear cell or papillary carcinoma, uterus endometrial carcinoma, ovarian cystadenocarcinoma and testicular germ cell tumors. Clinical data show a higher prevalence of GU cancers for men than women, suggesting significant molecular differences depending on sex regarding cancer development. This project aims at dissecting the expression landscape for all GU cancers and identify significant dysregulated genes between cancer and normal tissues specific either for men and women. The resulting data will serve a clinical application consisting in targeting novel molecular biomarkers detected in urine for GU cancers early diagnosis. Methods: Based on RNAseq data provided by The Cancer Genome Atlas, gene expression fold-change for 19,123 genes from cancer tissues and normal tissues was initially compared for each GU cancer. To ensure significant gene dysregulation, only genes showing a fold-change ≤ -log2(2) or ≥ log2(2) and a p-value < 0.05 were retained. Next, a comparison in gene expression modification between men and women for each cancer was made to identify the most significant molecular differences between both sexes. Unique dysregulated genes for each cancer were then identified and their presence or absence in urine was confirmed. From the pool of genes expressing proteins in urine, non-parametric tests for paired and unpaired values were used to determine the statistical difference between cancer and normal tissues in terms of gene expression. Results: Among 2880 genes significantly dysregulated for all five GU cancers, more than half of them were unique to BCa. Among these, 129 gene products (proteins) were ultimately detected in urine of patients. Seven up-regulated and ten down-regulated genes have shown high statistical differences between cancer and normal tissues in the Mann-Whitney U test for unpaired values. CEACAM6, S100A8 and S100A9 have shown significant differences in the Wilcoxon test for paired values which make them potential biomarkers ready for validation by LC-MS/MS. Conclusions: This present study shows the relevance to pursue research in gene expression modification in cancer to improve early diagnosis.

Transcriptome-wide analysis of alternative splicing events in bladder cancer: Novel biomarkers discovery for early diagnosis

483

Background: Cystoscopy, an invasive, painful and expensive method, is currently the main clinical tool for new diagnosis and disease recurrence detection of bladder cancer (BCa). The need for new biomarkers discovery that is costless, sensitive and specific is urgent. This project aims to study and compare alternative splicing events (ASE) in BCa tissues and normal bladder tissues and ultimately, identify specific spliced events coding for proteins detectable in urine by liquid chromatography–mass spectrometry. Methods: In this study, alterations to the global RNA splicing landscape of cellular genes were investigated in a large-scale screen from 408 BCa tissues and 19 normal tissues provided by The Cancer Genome Atlas (TCGA). Three statistical thresholds were used to determine substantial modifications. All events showing a p-value<0.05 and a level of expression ≥ 50 transcripts per million; -10 ≥ Δ percent splice index ≤10; and a q-value<0.05 were conserved. Next, mRNA expression levels between cancer and normal tissues were compared for all splicing factors and the spliceosome to determine the impact of gene dysregulation on alternative splicing events. Using multiple bioinformatic platforms such as EASANA, MultAlin, ExPasy, NLS Mapper and Pfam, splicing events responsible for significant protein structural changes between cancer and healthy tissue were selected. From this sample chosen, ASEs coding for proteins that could be detected in urine were conserved. Results: Our study identifies modifications in the alternative splicing patterns of 107 transcripts encoded by 97 genes. STRING analysis revealed that many of the gene products interact either directly or indirectly with each other (enrichment p-value = 1x10-10). 61 ASEs are causing important protein changes from which 27 can be detected in urine. Finally, 16 ASEs coding for easily recognizable peptide sequences in urine represented significant targets for potential BCa biomarkers. Conclusions: The TCGA data show the relevance to investigate alternative splicing events in bladder cancer. 16 significant events were detectable in urine and may potentially discriminate between presence or absence of bladder cancer.

Diagnosis and management of pancreatic exocrine insufficiency (PEI) in primary care: consensus guidance of a Canadian expert panel

BACKGROUND

Pancreatic exocrine insufficiency (PEI) results in maldigestion due to inadequate activity of pancreatic enzymes in the small bowel. PEI can arise from a variety of medical conditions that reduce enzyme synthesis within the pancreatic parenchyma or from secondary factors that may occur despite optimal parenchymal function, such as pancreatic duct obstruction or impaired or poorly synchronized enzyme release.

PURPOSE

To provide practical guidance for primary care physicians managing patients who are at risk of PEI or who present with symptoms of PEI.

METHODS

For each of six key clinical questions identified by the authors, PubMed searches were conducted to identify key English-language papers up to April 2017. Forward and backward searches on key articles were conducted using Web of Science. Clinical recommendations proposed by the co-chairs (P.D. and C.T.) were vetted and approved based on the authors?

FINDINGS

The most characteristic symptom of PEI is steatorrhea ? voluminous, lipid-rich stools; other common signs and symptoms include unexplained weight loss and deficiencies of fat-soluble vitamins and other micronutrients. Pancreatic enzyme replacement therapy (PERT) can relieve symptoms and long-term sequelae of PEI. Diagnosis of PEI and initiation of PERT are usually the responsibility of gastroenterology specialists. However, primary care physicians (PCPs) are well positioned to identify potential cases of PEI and to participate in the collaborative, long-term management of patients already seen by a specialist.

CONCLUSIONS

In this document, a panel of Canadian gastroenterologists has conducted a critical review of the literature on PEI and PERT and has developed practical diagnostic and treatment recommendations for PCPs. These recommendations provide guidance on identifying patients at risk of PEI, the triggers for PEI testing and referral, and best practices for co-managing patients with confirmed PEI.

Virtual Reality Therapy Versus Cognitive Behavior Therapy for Social Phobia: A Preliminary Controlled Study

Social phobia is one of the most frequent mental disorders and is accessible to two forms of scientifically validated treatments: anti-depressant drugs and cognitive behavior therapies (CBT). In this last case, graded exposure to feared social situations is one of the fundamental therapeutic ingredients. Virtual reality technologies are an interesting alternative to the standard exposure in social phobia, especially since studies have shown its usefulness for the fear of public speaking. This paper reports a preliminary study in which a virtual reality therapy (VRT), based on exposure to virtual environments, was used to treat social phobia. The sample consisted of 36 participants diagnosed with social phobia assigned to either VRT or a group-CBT (control condition). The virtual environments used in the treatment recreate four situations dealing with social anxiety: performance, intimacy, scrutiny, and assertiveness. With the help of the therapist, the patient learns adapted cognitions and behaviors in order to reduce anxiety in the corresponding real situations. Both treatments lasted 12 weeks, and sessions were delivered according to a treatment manual. Results showed statistically and clinically significant improvement in both conditions. The effect-sizes comparing the efficacy of VRT to the control traditional group-CBT revealed that the differences between the two treatments are trivial.

Experiential cognitive therapy in the treatment of panic disorders with agoraphobia: a controlled study

The use of a multicomponent cognitive-behavioral treatment strategy for panic disorder with agoraphobia is actually one of the preferred therapeutic approaches for this disturbance. This method involves a mixture of cognitive and behavioral techniques that are intended to help patients identify and modify their dysfunctional anxiety-related thoughts, beliefs and behavior. The paper presents a new treatment protocol for Panic Disorder and Agoraphobia, named Experiential-Cognitive Therapy (ECT) that integrates the use of virtual reality (VR) in a multicomponent cognitive-behavioral treatment strategy. The VR software used for the trial is freely downloadable: www.cyberpsychology.info/try.htm. Moreover, the paper presents the result of a controlled study involving 12 consecutive patients aged 35-53. The selected subjects were randomly divided in three groups: ECT group, that experienced the Cognitive Behavioral Therapy-Virtual Reality assisted treatment (eight sessions), a CBT group that experienced the traditional Cognitive Behavioral approach (12 sessions) and a waiting list control group. The data showed that both CBT and ECT could significantly reduce the number of panic attacks, the level of depression and both state and trait anxiety. However, ECT procured these results using 33% fewer sessions than CBT. This datum suggests that ECT could be better than CBT in relation to the "cost of administration," justifying the added use of VR equipment in the treatment of panic disorders.

Computer-assisted stereology: point fraction of lung parenchyma and alveolar surface density in fetal and newborn sheep

The aim of this study was to determine the accuracy of a new computer-assisted stereological technique in obtaining structural information of the lung. We compared the point fraction of lung parenchyma (Pp) and alveolar surface density (Sv) obtained by established manual point/intercept counting methods and compared them with those obtained using a computer-assisted method. Lung tissues obtained from normally grown fetal sheep (n = 6) and from newborn lambs with severe lung hypoplasia (n = 5) were inflation fixed via the trachea and processed for light microscopy. In verification-of-technique experiments, Pp and Sv correlated well with known values. There was a significant linear correlation between manual and computer-assisted stereological measurements for values of Pp (r2 = 0.92) and Sv (r2 = 0.98). Our data lead us to believe that the computer-assisted stereological technique described in this study provides accurate estimates of Pp and Sv and hence may be a valuable tool for evaluating the effects of factors upon structural development of the lung.

Virtual reality assisted cognitive behavioral therapy for the treatment of Panic Disorders with Agoraphobia

The chapter describes the characteristics of the Experiential-Cognitive Therapy (ECT) protocol for Panic Disorder and Agoraphobia. The goal of ECT is to decondition fear reactions, to modify misinterpretational cognition related to panic symptoms and to reduce anxiety symptoms. This is possible in an average of eight sessions of treatment plus an assessment phase and booster sessions, through the integration of Virtual Experience and traditional cognitive-behavioral techniques. We decided to employ the techniques included in the cognitive-behavioral approach because they showed high levels of efficacy. Through virtual environments we can gradually expose the patient to feared situation: virtual reality consent to re-create in our clinical office a real experiential world. The patient faces the feared stimuli in a context that is nearer to reality than imagination. For ECT we developed the Virtual Environments for Panic Disorders--VEPD--virtual reality system. VEPD is a 4-zone virtual environment developed using the Superscape VRT 5.6 toolkit. The four zones reproduce different potentially fearful situations--an elevator, a supermarket, a subway ride, and large square. In each zone the characteristics of the anxiety-related experience are defined by the therapist through a setup menu.

Estimation and application of EMG amplitude during dynamic contractions

The sections above have described an EMG amplitude estimator and an initial application of this estimator to the EMG-torque problem. The amplitude estimator consists of six stages. In the first stage, motion artifact and power-line interference are attenuated. Motion artifact is typically removed with a highpass filter. Elimination of power-line noise is more difficult. Commercial systems tend to use notch filters, accepting the concomitant loss of "true" signal power in exchange for simplicity and robustness. Adaptive methods may be preferable, however, to preserve more "true" signal power. In stage two, the signal is whitened. One fixed whitening technique and two adaptive whitening methods were described. For low-amplitude levels, the adaptive whitening technique that includes adaptive noise cancellation may be necessary. In stage three, multiple EMG channels (all overlying the same muscle) are combined. For most applications, simple gain normalization is all that is required. Stage four rectifies the signal and then applies the power law required to demodulate the signal. In stage six, the inverse of the power law is applied to relinearize the signal. Direct comparison of MAV (first power) to RMS (second power) processing demonstrates little difference between the two. Therefore, unless there is reason to believe that the EMG density departs strongly from that found in the existing studies, RMS and MAV processing are essentially identical. In stage five, the demodulated samples are averaged across all channels and then smoothed (time averaged) to reduce the variance of the amplitude estimate, but at the expense of increasing the bias. For best performance, the window length that best trades off variance and bias error is selected. The advanced EMG processing was next applied to dynamic EMG-torque estimation about the elbow joint. Results showed that improved EMG amplitude estimates led to improved EMG-torque estimates. An initial comparison of different system-identification techniques and model orders was reported. It is expected that these advanced processing and identification algorithms will also improve performance in other EMG applications, including myoelectrically controlled prostheses, biofeedback, and ergonomic assessment.

Expression of neuropeptides in normal and abnormal appendices

BACKGROUND/PURPOSE

Increased neuroproliferation in the appendix associated with an increase in substance P (SP), vasoactive intestinal polypeptide (VIP), and growth-associated protein-43 (GAP-43) has been documented in appendices of adults with acute right lower quadrant (RLQ) abdominal pain and absence of gross or histologic signs of appendiceal inflammation. The authors tested whether these findings were present in children with RLQ pain and a normal appendix.

METHODS

Immunohistochemistry staining of paraffin-embedded appendices was performed with GAP-43, VIP, and SP. The positive control group included appendices with acute inflammation (group I, n = 5); the negative control group included appendices removed incidentally (group II, n = 5); and the experimental group included appendices from children suspected to have acute appendicitis without histologic signs of inflammation (group III, n = 9).

RESULTS

Group I: VIP was strongly expressed in the nerve plexuses. The lamina propria and muscularis showed absent or minimal VIP expression. SP staining was strong in all plexuses and was moderate to strong in the muscularis. SP expression in the epithelium and lamina propria was difficult to quantify secondary to inflammation. Group II: VIP expression was essentially undetectable in the epithelium, lamina propria, and muscularis, and was moderate in the nerve plexuses. Mild SP staining was detected in the nerve plexuses of most specimens, and absent to mild staining was found in the epithelium and muscularis. However, one specimen strongly expressed SP in all layers. Group III: VIP expression was moderate to strong in the lamina propria and muscularis of nearly all specimens, and strong expression was found in all nerve plexuses. All but one specimen strongly expressed SP in plexuses. There was moderate to strong expression of SP in the epithelium, lamina propria, and muscularis in over 50% of specimens. The immunostaining for GAP-43 was very weak and nonspecific and did not help discriminate between the 3 study groups.

CONCLUSIONS

Increased neuroproliferation in the lamina propria and muscularis was evident in patients with abdominal pain and normal appendices compared with appendices removed incidentally. The VIP and SP expression in these patients was similar or higher than that observed in patients with acute inflammation on histology.

Pulmonary lymphangiectasia revisited

PURPOSE

Pulmonary lymphangiectasia (PL) is a rare, poorly documented disease characterized by abnormal pulmonary lymphatics. Although case reports are published, little is known about survivors past the neonatal period.

METHODS

This is a retrospective review of histologically proven PL in fetuses, infants, and long term survivors since 1965.

RESULTS

Eleven children (8 boys, 3 girls) and 8 aborted fetuses (7 male, 1 female) were identified. The fetuses weighed 463.4 g (177 to 681 g). Six were aborted between 19 to 24 weeks of gestation for multiple malformations or anencephaly, and 2 spontaneously aborted: one with PL only, the other with twin-twin transfusion syndrome. Clinical PL was diagnosed between 0 and 11 months of age. Six children died (2 neonatal, 4 within 10 days), 5 survived. Two deaths occurred after cardiac surgery. Among survivors, the symptomatology and frequency of admissions diminished over time. Symptoms included progressive respiratory distress, chronic cough, recurrent pneumonia, bronchial asthma, and choking. One child with bilateral chylothorax was later diagnosed with Noonan syndrome; 2 patients had minor cardiac malformations. Rapid deterioration occurred with mild respiratory infections with only supportive treatment available. Chest x-ray showed marked hyperinflation with interstitial infiltrate.

CONCLUSIONS

This is the first long-term study of primary PL and will help counsel parents. Although fatal in the neonatal period, survival is possible if diagnosed past the neonatal period and improvement is expected.

Pleuropulmonary blastoma: a rare pathology with an even rarer presentation

BACKGROUND

Pleuropulmonary blastoma is among the rarest tumors of childhood. Three types have been described: cystic, solid, and mixed. To date, bilateral disease has not been documented.

METHODS AND RESULTS

A 5-week-old girl presented with a history of fever. Chest x-ray showed bilateral diffuse cystic lesions. Bowel obstruction developed that required laparotomy. Multiple small bowel polyps were resected. The patient was readmitted 4 months later with deteriorating respiratory status. She underwent sequential thoracotomies for resection of multiple bullae under high-frequency oscillatory ventilation. Small bowel polypectomies were again required because of obstruction. Lung lesions were compatible with pulmonary blastoma but could not be correlated with intestinal polyposis. Bilateral cystic renal lesions were seen on ultrasound scan. Her disease progressed, despite chemotherapy, with the appearance of metastatic iris lesions. She again underwent laparotomies for multiple recurrent generalized small bowel polyps that were causing obstruction. Expanding renal cysts affected kidney function, and she died at 14 months of age.

CONCLUSIONS

The rare association between pleuropulmonary blastoma and Wilms' tumor or nephroblastomatosis is known but rarely reported. Lacking pathological evidence, we can only speculate that this was the case. We have been unable to demonstrate any histological association between the renopulmonary and digestive lesions. Despite many unanswered questions, we are likely dealing with a "syndrome" of sorts with a dire outcome, despite aggressive treatments.

The otolaryngologic manifestations of gastroesophageal reflux: when is a pH study indicated?

PURPOSE

The aim of this study was to evaluate the pertinence of pH studies for persistent ear, nose, and throat (ENT) symptoms and their eventual relationship to gastroesophageal reflux (GER).

METHODS

Retrospective analysis was performed of age, reason for referral, pH study, treatment, and follow-up of patients with ENT symptoms suspected to have GER.

RESULTS

Of 3,000 esophageal pH studies performed over 16 years, 105 children were referred for ENT symptoms by an otorhinolaryngologist to rule out GER. Mean age was 33 months; 65% were boys. Reasons for referral included (number and mean age): stridor (n = 31, 8 months), laryngomalacia (n = 18, 13 months), recurrent otitis (n = 12, 42 months), laryngitis (n = 16, 50 months), dysphonia (n = 14, 59 months), laryngeal papillomatosis (n = 8, 62 months), sinusitis (n = 5, 56 months), and dysphagia (n = 1). Overall, 41% of study results were positive: stridor (58%), laryngomalacia (61%), laryngitis (56%) and sinusitis (40%). Patients with otitis, dysphonia and laryngeal papillomatosis had GER in 1%, 14%, and 25%, respectively. Follow-up in the three larger groups of patients showed resolution of the ENT symptoms after medical treatment of the reflux in 83% of patients with stridor and reflux, 86% with laryngitis and reflux, and 80% with laryngomalacia and reflux. Four fundoplications were performed: one neurologically impaired patient, and four nonresponders.

CONCLUSIONS

The authors recommend that a pH study be performed in children with stridor, laryngomalacia, laryngitis, and sinusitis when faced with failure of the usual treatment. However, a pH study does not seem as beneficial for recurrent otitis, dysphonia, or laryngeal papillomatosis.

Falls from heights among children: a retrospective review

BACKGROUND

Falls are a major cause of emergency room visits and admissions in pediatric hospitals.

METHODS

To better understand the epidemiology of falls from height and develop prevention strategies, the authors reviewed all admissions after a fall at a single institution from 1994 to 1997. Inclusion criteria are falls from a minimum height of 10 feet.

RESULTS

Of 1,410 patients admitted after a fall, 64 patients including 45 boys and 19 girls with a mean age of 7.4 years (range, 1 to 18) are included in this study. Fifty (78%) children fell from 20 feet or less (two stories) and 14 (22%) from height greater than 20 feet. Patients mainly fell from balconies (n = 15), windows (n = 13), trees (n = 9), roofs (n = 6), stairs (n = 6), diving board (n = 3) and miscellaneous (n = 12). Over 60% of falls occurred in private houses and during the summer months. Fifty-five patients (86%) sustained only one system injury, two patients had no significant injury, and seven patients had multisystem injury. Major injuries included head trauma (39%), musculoskeletal (34%), abdominal (12%), maxillofacial (8%), and spine (6%). A surgical intervention was required for 43% of intracranial trauma, 39% of musculoskeletal injuries, 60% of facial trauma, and 50% of spine fractures. Mean length of stay in hospital varied according to the injured system. The overall survival rate is 98% with only one death after a fall greater than 50 feet.

CONCLUSIONS

Although rarely mortal, falls from height carry a significant morbidity and are costly to the health care system. To decrease the occurrence of injuries caused by falls, strategies should include awareness campaigns, parent's education about the mechanisms of falls, increase parenteral supervision during playing activities, and legislative measures to ensure the safety of windows and balconies before the onset of summer.

Perineal hemangioma, anorectal malformation, and genital anomaly: a new association?

Two patients presented as full-term baby girls with anorectal and genital malformations with extensive perineal hemangiomas. The first patient had a vestibular anus with a perineal hemangioma involving the bladder, rectal, and vaginal walls. Skin ulcerations required a transverse loop colostomy for wound care. The vulva, urethral opening, and clitoris were deviated to the left, labia minora were absent, and the labia majora were abnormal. The second patient had an anus displaced anteriorly and deviated to the right. The external anal sphincter was hypertrophic on the left and atrophic on the right. Rectal examination showed agenesis of the right levator ani and a dentate line located at the skin level. She had a large perineal, sacral, vaginal, pararectal and retroperitoneal hemangioma and developed extensive skin ulcerations. She had only a hemiclitoris located to the left of the midline, near absence of labia minora, and hypertrophied labia majora. The urethra was displaced to the left and opened in the vestibule. Both patients had a spinal malformation (one with tethered cord and one with spina bifida) and a normal karyotype. Steroids and interferon allowed near-complete resolution of hemangiomas in both patients. The authors were impressed by the similarity of these two cases and could not find any previous description of this association.

Cyclic traction machine for long-term culture of fibroblast-populated collagen gels

Our research group has been investigating the effect of cyclic deformations on the evolution of fibroblast populated collagen gels (FPCG). Since existing traction machines are not designed for such an application, we had to design a cyclic traction machine adapted to tissue culture inside an incubator over an extended period of time. Biocompatible materials were used for fabrication to allow for easy sterilization and to prevent any adverse reaction from the tissue. The traction machine is based on a computer-controlled stepping motor system for easy adjustment of the deformation amplitude and frequency. The maximum stretching speed achieved is around 1 mm/s. The traction machine can measure FPCG mechanical properties and perform rupture tests to determine its ultimate strength. Several FPCGs have been successfully cultured with the machine for up to four weeks without any adverse reaction.

Predictors of post-ERCP complications in patients with suspected choledocholithiasis

BACKGROUND AND STUDY AIMS

Determinants of complications after endoscopic retrograde cholangiopancreatography (ERCP) have not yet been completely characterized.

PATIENTS AND METHODS

Data were collected from an endoscopic database. Univariate analysis and multivariate logistic regression analysis were used to generate the best model of independent predictors of post-ERCP pancreatitis.

RESULTS

The database included 1239 ERCP examinations carried out to investigate suspected choledocholithiasis over a five-year period. From these, 45 patients who developed post-ERCP complications were compared to a random sample of 486 patients who had undergone an uncomplicated ERCP for suspected choledocholithiasis. Univariate analysis demonstrated significant differences between the two patient groups for the following factors: age, using a cut-off point of 59 years (27% vs. 51%, P = 0.002), pancreatic channel opacification (73% vs. 58%, P = 0.05), and absence of common bile duct stones (41% vs. 24%, P = 0.03). Using multivariate logistic regression, the best model for predicting post-ERCP pancreatitis in patients undergoing sphincterotomy included age under 59 years (P = 0.04), and absence of a common bile duct stone (P = 0.004). The model yielded probabilities of developing post-sphincterotomy pancreatitis that ranged from 2.8% if no predictor was present, to 27% when both predictors were present. Among patients in whom a sphincterotomy was not performed, the only significant independent predictor found was pancreatic channel opacification (P = 0.05).

CONCLUSION

Age under 59 years, pancreatic channel opacification, and an absence of common bile duct stones at ERCP are all independent predictors of post-ERCP pancreatitis.

Toward a dynamic topographic components model

Möcks' topographic component model (TCM) (Möcks, J. Topographic components model for event-related potentials and some biophysical considerations. IEEE Trans. Biomed. Eng., 1988a, 35: 482-484; Möcks, J. Decomposing event-related potentials: a new topographic components model. Biol. Psychol., 1988b, 26: 199-215) decomposes event-related potentials into components uniquely determined by their respective amplitude profiles across replicates, assuming a constant topography and wave shape for each component. To accommodate possible changes in the component expression across conditions, a dynamic version of TCM is investigated which further admits component modulation in time scale. Twenty test problems were synthesized, incorporating two arbitrary topographies each activated with its own arbitrary wave shape modified, across two conditions, in amplitude, onset and duration. Seventeen problems were perfectly solved, with substantial success on the remaining three, confirming that component jitter or stretching can even help component identification.

The development of an empirical psychosocial taxonomy for patients with diabetes

The main purpose of this study was to develop and to cross-validate an empirically derived psychosocial taxonomy of patients with diabetes. In the first study, 101 patients with Type I or Type II diabetes completed the Multidimensional Diabetes Questionnaire. Cluster analysis identified three clusters, labeled adaptive copers, low support-low involvement, and spousal overinvolvement. In the second study, the taxonomy was cross-validated using an independent sample of 132 patients with long-standing Type II diabetes. The results confirmed that the multivariate classification system was unique and highly accurate. External validation, using general psychological as well as diabetes-specific measures, supported the validity and distinctiveness of the patients' profiles. These findings help establish a multiaxial psychosocial taxonomy of diabetes and may have significant implications for the management of patients with diabetes.

Pediatric surgeons' activities and future plans

OBJECTIVE

The authors aim was to survey members of the Canadian Association of Paediatric Surgeons (CAPS) on their demographics, practice, and future plans.

MATERIALS AND METHODS

A questionnaire was mailed to 86 members.

RESULTS

We received 60 questionnaires (70%), with a return rate including 85% men and 15% women. Seventeen percent of the respondents do not have children, 8% did not answer the question pertaining to children, and 8% expect to have more children. Among the 75% of surgeons with children, 16% have reduced the number of hours worked, from 2 hours to more than 1 day per week, for a number of years. Younger surgeons and women are more likely to reduce their work load for their family life. Most surgeons practice in an academic (64%) or a mixed setting (25%), with only 12% involved in private practice. On average, 69% of their time is devoted to patient care; teaching and research each take an average of 10% of the surgeon's time, while 9% of their time is spent on administrative duties. Study respondents work an average of 57 hours per week, and 45 weeks per year. Age significantly influenced the number of hours worked per week, and the number of weeks worked on a yearly basis. Gender and type of practices did not significantly influence the number of hours or weeks worked, whereas location of practice did. Spouse activity also had an impact on the number of hours and weeks worked. When asked about their preference for the next 5 years, 30% of surgeons would opt for a decrease in their level of activity, and 15% wish to retire. Irrespective of the age group or the type of practice, surgeons would prefer to decrease their level of activity. A recurring theme submitted by respondents is the need for increased time for teaching and research and less administrative work. Finally, 60% of surgeons were very satisfied with their work, 27% were satisfied, and 12% were unsatisfied.

CONCLUSION

Lifestyle and family commitment have an impact on pediatric surgeons' activity and should be considered when analyzing work force requirements.

The development of an empirical psychosocial taxonomy for patients with diabetes

The main purpose of this study was to develop and to cross-validate an empirically derived psychosocial taxonomy of patients with diabetes. In the first study, 101 patients with Type I or Type II diabetes completed the Multidimensional Diabetes Questionnaire. Cluster analysis identified three clusters, labeled adaptive copers, low support-low involvement, and spousal overinvolvement. In the second study, the taxonomy was cross-validated using an independent sample of 132 patients with long-standing Type II diabetes. The results confirmed that the multivariate classification system was unique and highly accurate. External validation, using general psychological as well as diabetes-specific measures, supported the validity and distinctiveness of the patients' profiles. These findings help establish a multiaxial psychosocial taxonomy of diabetes and may have significant implications for the management of patients with diabetes.

The assessment of panic using self-report: a comprehensive survey of validated instruments

A repertoire of reliable and valid self-report instruments to assess panic and panic disorder would help both researchers and clinicians. This review presents a description and an analysis of the available instruments. Following a comprehensive search of the literature, 14 instruments with published information on reliability and validity were reviewed. The following information is reported for each instrument: brief description of the instrument and its development, mean and standard deviation for clinical and nonclinical samples, and psychometric properties. Four types of instruments are presented: general assessment and information (n = 2), severity of panic disorder (n = 2), body sensations (n = 2) and cognitive dimensions of panic (n = 8). Overall, it would seem that panic measures have moderate to excellent psychometric qualities. However, the comparison between the instruments is difficult because the amount of empirical support available varies widely from one instrument to the other.

Helicobacter pylori infection in Eastern Europe: seroprevalence in the Polish population of Lower Silesia

The Helicobacter pylori status of the population of Eastern European countries has not been explored despite the high incidence of peptic ulcer disease and gastric cancer observed in these countries. A seroprevalence study has been performed in Wroclaw, a city of Lower Silesia, Poland, to provide insight into this question. Sera were collected to obtain 50 subjects per 5 yr increment of age. A second generation ELISA kit with a high sensitivity and specificity was used. The results plotted by year of birth show a very high prevalence of H. pylori infection in all adults groups born before 1970 (80-100% positive). In the younger age groups, a dramatic decrease was observed. Because it is now known that most H. pylori infections are acquired in childhood (cohort effect), it can be predicted that the infection rate in the adult population will be much lower in the future compared with that presently observed, and it can be expected that evolution in H. pylori prevalence will have an impact on the rate of gastroduodenal diseases in Poland. Because of the high prevalence, it was not possible to identify risk factors for infection in this population.

Long-term stability of diagnosis and symptom dimensions in a systematic sample of patients with onset of schizophrenia in childhood and early adolescence. II: Postnegative distinction and childhood predictors of adult outcome

BACKGROUND

The aim of this study was to verify the presence and stability across life of the positive/negative distinction in early-onset schizophrenia (EO-SZ) through a longitudinal factor analysis of the schizophrenic dimensions, and to identify the factors predicting several indices of long-term outcome for EO-SZ.

METHOD

Forty children consecutively referred for DSM-III-R schizophrenia (SZ) in a specific catchment area comprised the sample.

RESULTS

Across a 14.8-year follow-up, longitudinal factor analysis identified two separate factors corresponding to the positive and negative symptom dimensions. We also observed that: the GAS rated over the last three years of adult illness and the severity of negative symptoms during the stabilised interepisode intervals in adulthood were the indices of adult outcome that were most easily predicted; and the best childhood predictors of adult outcome were premorbid functioning and severity of positive and negative symptoms during acute episodes.

CONCLUSIONS

The presence of premorbid non-psychotic behaviour disturbances (NPBD) and premorbid developmental problems was not related to severity of outcome, in contrast to the former variables.

Long-term stability of diagnosis and symptom dimensions in a systematic sample of patients with onset of schizophrenia in childhood and early adolescence. I: nosology, sex and age of onset

BACKGROUND

Little is known about the long-term outcome of schizophrenia that has its onset during childhood and early adolescence (early-onset schizophrenia, or EO-SZ). Whether or not EO-SZ is an aetiologically separate form of schizophrenia (SZ) is unresolved.

METHOD

The study was a 14.8-year follow-up, using methods such as systematic sampling, evaluation of possible non-respondent bias, consensus best-estimate diagnoses (DSM-III-R) made independently in childhood and adulthood, measures of positive and negative dimensions, of non-psychotic behaviour disturbances (NPBD) and of developmental problems before the appearance of SZ.

RESULTS

There was high stability of EO-SZ (n = 40) diagnoses (mean onset at 14.0 years) until adulthood (mean age at follow-up 28.8 years) but a lower stability of positive and negative schizophrenic dimensions. There was a poor outcome of EO-SZ, a strong over-representation of males but few gender differences, and no effect of age of onset on clinical features and outcome.

CONCLUSIONS

EO-SZ taken as a whole shows no qualitative differences to adult-onset SZ. However, a distinction through the onset of preschizophrenic developmental problems or NPBD might be a way to investigate heterogeneity within EO-SZ.

Exposure versus cognitive restructuring in the treatment of panic disorder with agoraphobia

The aim of this study was to assess the rate of change on clinical, behavioral and cognitive variables during exposure therapy and cognitive restructuring in the treatment of panic disorder with agoraphobia. A total of 28 Ss who received a diagnosis of panic disorder with agoraphobia were randomly assigned to either of two treatment conditions: exposure therapy or cognitive restructuring. Treatment conditions were kept as distinct as possible from each other. Subjects were assessed on five occasions: pretreatment, after 5, 10, and 15 (posttreatment) sessions of treatment and at a 6-month follow-up. Analyses of outcome data revealed strong and significant time effects on all measures. However, no group x time interaction reached statistical significance, suggesting that both strategies operate at the same pace. Furthermore, power analyses suggest that any difference that might exist in the rate of improvement between exposure and cognitive restructuring in the treatment of panic disorder with agoraphobia is marginal.

Technology assessment in laparoscopic general surgery and gastrointestinal endoscopy: science or convenience?

Gastrointestinal endoscopy and laparoscopic general surgery have been significantly affected by the emergence of new techniques. These two disciplines share many similarities, including the use of sophisticated and expensive technologies. Their proper assessment is essential because they are developed amidst ever-decreasing health care budgets. Gastroenterologists and general surgeons must both participate in such evaluations and feel confident in interpreting pertinent published data. The present review uses a clinician's point of view with relevant examples to discuss the methodologies adopted in technology assessment and to highlight common pitfalls encountered in study design, patient selection, timing and selection of the study, blinding, and outcome measurement. Cost and statistical considerations, as well as ethical issues, are also reviewed in the context of technology assessment.

Farmer's lung and variables related to the decision to quit farming

An exploratory strategy was used to investigate why 55% of patients with farmer's lung (FL) disease quit farming. Three groups were recruited: 47 patients with FL disease who quit farming because of the disease (FLq), 76 patients with FL disease who continued farming (FLc), and 123 control farmers without a history of FL disease. The severity of FL disease at diagnosis was similar in both groups of patients. For example, single-breath carbon monoxide diffusion capacity predicted for FLq and FLc was 64.4 +/- 28.2 and 63.9 +/- 22.0, respectively. Relying on a cognitive-behavior theory, numerous physiological, behavioral, cognitive, affective, and social variables were assessed. Results showed that the decision to quit farming was based on cognitive and behavioral motives rather than physiological factors. Subjects in the FLq group showed more negative beliefs toward FL and had more fears of FL disease. FLq subjects also reported that family members, friends, and family doctors were more inclined to consider that FL disease could stop them from farming. However, self-efficacy to continue farming despite having FL disease and perceived hindrance caused by FL disease played the most important roles in the decision to quit farming.

Behavioral and biochemical effect of chronic treatment with D-1 and/or D-2 dopamine agonists in MPTP monkeys

Monkeys developed a severe parkinsonian syndrome after intravenous administration of (MPTP). L-DOPA/carbidopa (D-1 and D-2) or bromocriptine (D-2) treatment relieved the parkinsonian symptoms, whereas SKF 38393 (D-1) was ineffective. No dyskinesia was seen in monkeys receiving bromocriptine or SKF 38393 as opposed to the L-DOPA-treated animals, in which the dyskinetic response appeared to increased with time. MPTP induced a significant increase (25%, P less than 0.01) in the number of [3H]spiperone binding sites (Bmax) in the caudate nucleus and in putamen. The Bmax of spiperone binding in the L-DOPA-treated monkeys was on average 18% lower (P less than 0.01) than that of the animals treated with MPTP alone. The Bmax for the bromocriptine-treated group was 29% (P less than 0.01) less than that in the MPTP-treated group or 11% (P less than 0.05) less than that in the L-DOPA-treated monkeys. The SKF 38393 treatment induced a 23% (P less than 0.01) decrease in the Bmax as compared to that of animals treated with MPTP alone, and no significant change compared to the L-DOPA- or bromocriptine-treated animals. These results suggest that stimulation of D-1 and D-2 dopamine receptors can differently influence the mechanisms controlling dopamine agonist-induced dyskinesia in MPTP-treated monkeys.

Tizanidine versus baclofen in the treatment of spasticity in patients with multiple sclerosis

Tizanidine (Sirdalud) was compared to baclofen (Lioresal) in a randomized, double-blind, cross-over trial. Each medication was introduced over a three week titration period and then maintained at the highest tolerated dose for five weeks. The two treatment phases were separated by a one week drug withdrawal and a two week washout period. Sixty-six patients entered the trial and forty-eight completed both treatment phases. At the end of the trial, neurologists and physiotherapists thought that baclofen was superior on the basis of perceived efficacy and tolerance (p less than or equal to 0.05). Although the efficacy of tizanidine or baclofen was judged as good to excellent by 24 and 39% of patients respectively, this difference was not statistically significant. Muscle weakness was the most common adverse effect. This was significantly more troublesome in patients treated with baclofen. Somnolence and xerostomia were more common in patients treated with tizanidine. Both baclofen and tizanidine appear to be useful adjuncts in the treatment of spasticity in patients with multiple sclerosis. Preference of either drug is tempered principally by side-effects.

A comparison of bromocriptine (Parlodel) and levodopa-carbidopa (Sinemet) for treatment of "de novo" Parkinson's disease patients

Fifty-one patients were enrolled in a double-blind, parallel group, multicentre study conducted to assess short-term efficacy and tolerance of bromocriptine (Parlodel) or L-DOPA/carbidopa (Sinemet) in patients never treated with amantadine, ergot alkaloids or L-DOPA-based drugs. An attempt to use the lowest effective dose was made. The responder rate for each group was approximately 78%; the mean daily dose for responders was 22.5 mg of bromocriptine or 250 mg of L-DOPA/carbidopa. The overall clinical improvement in each group was 62% (bromocriptine) and 55% (L-DOPA/carbidopa) for neurological assessment and 36% (bromocriptine) and 31% (L-DOPA/carbidopa) for functional disability. Comparison between groups did not show any significant difference for both neurological and disability assessments. The most frequent side effect was nausea (L-DOPA, N = 3; bromocriptine, N = 6).