Evaluation of bowel preparation regimens for colonoscopy including a novel low volume regimen (Plenvu): CLEANSE study

BACKGROUND

Poor bowel preparation is the leading cause of failed colonoscopies and increases costs significantly. Several, split preparation, 2 day regimens are available and recently, Plenvu, a low-volume preparation which can be given on 1 day has been introduced.

AIMS

Assess efficacy and tolerability of commonly used purgative regimens including Plenvu.

METHOD

In this service evaluation, patients undergoing screening colonoscopy at St Mark's Hospital, London (February 2020-December 2021) were provided Plenvu (1 or 2 days), Moviprep (2 days) or Senna & Citramag (2 days).Boston Bowel Preparation Scale (BBPS) score, fluid volumes and procedure times were recorded. A patient experience questionnaire evaluated taste, volume acceptability, completion and side effects.

RESULTS

563 patients were invited to participate and 553 included: 218 Moviprep 2 days, 108 Senna & Citramag 2 days, 152 Plenvu 2 days and 75 Plenvu 1 day.BBPS scores were higher with Plenvu 1 and 2 days vs Senna & Citramag (p=0.003 and 0.002, respectively) and vs Moviprep (p=0.003 and 0.001, respectively). No other significant pairwise BBPS differences and no difference in preparation adequacy was seen between the groups.Patients rated taste as most pleasant with Senna & Citramag and this achieved significance versus Plenvu 1 day and 2 days (p=0.002 and p<0.001, respectively) and versus Moviprep (p=0.04).

CONCLUSION

BBPS score was higher for 1 day and 2 days Plenvu versus both Senna & Citramag and Moviprep. Taste was not highly rated for Plenvu but it appears to offer effective cleansing even when given as a same day preparation.

Evaluation of a real-time computer-aided polyp detection system during screening colonoscopy: AI-DETECT study

BACKGROUND

Polyp detection and resection during colonoscopy significantly reduce long-term colorectal cancer risk. Computer-aided detection (CADe) may increase polyp identification but has undergone limited clinical evaluation. Our aim was to assess the effectiveness of CADe at colonoscopy within a bowel cancer screening program (BCSP).

METHODS

This prospective, randomized controlled trial involved all eight screening-accredited colonoscopists at an English National Health Service (NHS) BCSP center (February 2020 to December 2021). Patients were randomized to CADe or standard colonoscopy. Patients meeting NHS criteria for bowel cancer screening were included. The primary outcome of interest was polyp detection rate (PDR).

RESULTS

658 patients were invited and 44 were excluded. A total of 614 patients were randomized to CADe (n = 308) or standard colonoscopy (n = 306); 35 cases were excluded from the per-protocol analysis due to poor bowel preparation (n = 10), an incomplete procedure (n = 24), or a data issue (n = 1). Endocuff Vision was frequently used and evenly distributed (71.7 % CADe and 69.2 % standard). On intention-to-treat (ITT) analysis, there was a borderline significant difference in PDR (85.7 % vs. 79.7 %; P = 0.05) but no significant difference in adenoma detection rate (ADR; 71.4 % vs. 65.0 %; P = 0.09) for CADe vs. standard groups, respectively. On per-protocol analysis, no significant difference was observed in these rates. There was no significant difference in procedure times.

CONCLUSIONS

In high-performing colonoscopists in a BCSP who routinely used Endocuff Vision, CADe improved PDR but not ADR. CADe appeared to have limited benefit in a BCSP setting where procedures are performed by experienced colonoscopists.

Implementation of optical diagnosis with a "resect and discard" strategy in clinical practice: DISCARD3 study

BACKGROUND AND AIMS

Optical diagnosis (OD) of polyps can be performed with advanced endoscopic imaging. For high-confidence diagnoses, a "resect and discard" strategy could offer significant histopathology time and cost savings. The implementation threshold is a ≥90% OD-histology surveillance interval concordance. Here we assessed the OD learning curve and feasibility of a resect and discard strategy for ≤5-mm and <10-mm polyps in a bowel cancer screening setting.

METHODS

In this prospective feasibility study, 8 bowel cancer screening endoscopists completed a validated OD training module and performed procedures. All <10-mm consecutive polyps had white-light and narrow-band images taken and were given high- or low-confidence diagnoses until 120 high-confidence ≤5-mm polyp diagnoses had been performed. All polyps had standard histology. High-confidence OD errors underwent root-cause analysis. Histology and OD-derived surveillance intervals were calculated.

RESULTS

Of 565 invited patients, 525 patients were included. A total of 1560 <10-mm polyps underwent OD and were resected and retrieved (1329 ≤5 mm and 231 6-9 mm). There were no <10-mm polyp cancers. High-confidence OD was accurate in 81.5% of ≤5-mm and 92.8% of 6-9-mm polyps. Sensitivity for OD of a ≤5-mm adenoma was 93.0% with a positive predictive value of 90.8%. OD-histology surveillance interval concordance for ≤5-mm OD was 91.3% (209/229) for U.S. Multi-Society Task Force, 98.3% (225/229) for European Society of Gastrointestinal Endoscopy, and 98.7% (226/229) for British Society of Gastroenterology guidelines, respectively.

CONCLUSIONS

A resect and discard strategy for high-confidence ≤5-mm polyp OD in a group of bowel cancer screening colonoscopists is feasible and safe, with performance exceeding the 90% surveillance interval concordance required for implementation in clinical practice. (Clinical trial registration number: NCT04710693.).

Validation of post-colonoscopy colorectal cancer (PCCRC) cases reported at national level following local root cause analysis: REFLECT study

OBJECTIVE

Our aim was to determine aetiology of post-colonoscopy colorectal cancers (PCCRCs) identified from population-based data through local root cause analysis at a high-volume mixed secondary and tertiary referral centre.

DESIGN/METHOD

A subset of national cancer registration data, collected by the National Cancer Registration and Analysis Service, was used to determine PCCRCs diagnosed between 2005 and 2013 at our centre.Root cause analysis was performed for each identified PCCRC, using World Endoscopy Organisation recommendations, to validate it and assess most plausible explanation. We also assessed whether patient, clinician and/or service factors were primarily responsible.

RESULTS

Of 107 'PCCRC' cases provided from the national dataset, 20 were excluded (16 missing data, 4 duplicates). 87 'PCCRC' cases were included of which 58 were true PCCRCs and 29 false PCCRCs.False PCCRCs comprised 17 detected cancers (cancer diagnosed within 6 months of negative colonoscopy) and 12 cases did not meet PCCRC criteria. Inflammatory bowel disease was the most common risk factor (18/58) and the most common site was rectum (19/58). The most common explanation was 'possible missed lesion, prior examination negative but inadequate' (23/58) and clinician factors were primarily responsible for PCCRC occurrence in most cases (37/58).

CONCLUSION

Our single-centre study shows, after local analysis, there was misclassification of PCCRCs identified from a population-based registry. The degree of such error will vary between registries. Most PCCRCs occurred in cases of sub-optimal examination as indicated by poor photodocumentation. Effective mechanisms to feedback root cause analyses are critical for quality improvement.

1314 Ad-Hoc Suturing Course Teaching: A Valuable Tool for A New Starter

Aim

The study aims to assess effectiveness of a three-hour suturing skills course for healthcare professionals at a tertiary hospital in London. Intended outcomes were improvement in confidence and proficiency at simple interrupted sutures.

Method

Four suturing sessions were delivered over five months to healthcare workers new to the clinical setting. The session included lecture, video, and practical skills. Participants completed a pre- and post-course survey to measure confidence levels in suturing using Likert scale. Participants performed simple interrupted sutures for 10 minutes in a pre- and post-course assessment. Performance was assessed using a suturing proficiency proforma. Pre- and post-course data was compared to assess improvement.

Results

Fifty participants attended the course. 93% had previous suturing teaching. Pre-course confidence in simple interrupted suture was 3.1 (SD = 1.2) and post course was 4.8 (SD = 0.2). One tailed T score was 14.7, and the difference was significant (p &lt; 0.05). Pre- and post-course assessment demonstrated improvement in the following parameters and participant proportions: handling of the needle driver (50%, n = 25), adequate placement of needle driver (68%, n = 34), appropriate needle angle entering skin (60%, n = 30), following needle curve (36%, n = 18), non-touch technique (64%, n = 32), surgical knot tying (56%, n = 28). Average number of sutures completed in 10 minutes increased by 1.9 times.

Conclusions

The majority of participants had previously been taught suturing in other settings; however, data demonstrated improvement in confidence and performance. Ad-hoc suturing skill teaching is a valuable tool to increase confidence of healthcare workers at early stages in their careers.

Diagnosis and management of iatrogenic endoscopic perforations: European Society of Gastrointestinal Endoscopy (ESGE) Position Statement - Update 2020

1:  ESGE recommends that each center implements a written policy regarding the management of iatrogenic perforations, including the definition of procedures that carry a higher risk of this complication. This policy should be shared with the radiologists and surgeons at each center. 2 : ESGE recommends that in the case of an endoscopically identified perforation, the endoscopist reports its size and location, with an image, and statement of the endoscopic treatment that has been applied. 3:  ESGE recommends that symptoms or signs suggestive of iatrogenic perforation after an endoscopic procedure should be rapidly and carefully evaluated and documented with a computed tomography (CT) scan. 4 : ESGE recommends that endoscopic closure should be considered depending on the type of the iatrogenic perforation, its size, and the endoscopist expertise available at the center. Switch to carbon dioxide (CO2) endoscopic insufflation, diversion of digestive luminal content, and decompression of tension pneumoperitoneum or pneumothorax should also be performed. 5 : ESGE recommends that after endoscopic closure of an iatrogenic perforation, further management should be based on the estimated success of the endoscopic closure and on the general clinical condition of the patient. In the case of no or failed endoscopic closure of an iatrogenic perforation, and in patients whose clinical condition is deteriorating, hospitalization and surgical consultation are recommended.

Golimumab: early experience and medium-term outcomes from two UK tertiary IBD centres

OBJECTIVE

To gain an understanding of the effectiveness of golimumab in a 'real-world' setting.

DESIGN

Retrospective cohort study using prospectively maintained clinical records.

SETTING

Two UK tertiary IBD centres.

PATIENTS

Patients with ulcerative colitis (UC) were given golimumab at Guy's & St Thomas and King's College Hospitals between September 2014 and December 2016.

INTERVENTION

Golimumab, a subcutaneously administered antitumour necrosis factor agent.

MAIN OUTCOME MEASURES

Clinical disease activity was assessed at baseline and at the first clinical review following induction therapy using the Simple Clinical Colitis Activity Index (SCCAI). Response was defined as an SCCAI reduction of 3 points or more. Remission was defined as an SCCAI of less than 3.

RESULTS

Fifty-seven patients with UC completed golimumab induction therapy. Paired preinduction and postinduction SCCAI values were available for 31 patients and fell significantly from 7 (2-19) to 3 (0-11) (p<0.001). To these 31, an additional 13 patients who did not have paired SCCAI data but stopped treatment due to documented 'non-response' in the opinion of their supervising clinician, were added. Among this combined cohort, 23/44 (52%) had a clinical response, 15/44 (34%) achieved remission and 13/44 (30%) achieved corticosteroid-free remission.Faecal calprotectin and CRP fell (FC: pre-induction: 1096 (15-4800) μg/g, post-induction: 114 (11-4800) μg/g, p = 0.011; n = 20; CRP: pre-induction: 4 (1-59) mg/L, post-induction: 2 (1-34) mg/L, p = 0.01 for n = 43). Post-induction endoscopy was carried out in 23 patients and a mucosal healing (Mayo 0 or 1) rate of 35% was observed.

CONCLUSIONS

Our experience mirrors previously reported real-world cohorts and demonstrates similar outcomes to those observed in randomised controlled trials. These data demonstrate a meaningful reduction in clinical, biochemical and endoscopic disease activity as well as a steroid-sparing effect in patients with previously refractory disease.

Co-culture of chondrons and mesenchymal stromal cells reduces the loss of collagen VI and improves extracellular matrix production

Adult articular chondrocytes are surrounded by a pericellular matrix (PCM) to form a chondron. The PCM is rich in hyaluronan, proteoglycans, and collagen II, and it is the exclusive location of collagen VI in articular cartilage. Collagen VI anchors the chondrocyte to the PCM. It has been suggested that co-culture of chondrons with mesenchymal stromal cells (MSCs) might enhance extracellular matrix (ECM) production. This co-culture study investigates whether MSCs help to preserve the PCM and increase ECM production. Primary bovine chondrons or chondrocytes or rat MSCs were cultured alone to establish a baseline level for ECM production. A xenogeneic co-culture monolayer model using rat MSCs (20, 50, and 80%) was established. PCM maintenance and ECM production were assessed by biochemical assays, immunofluorescence, and histological staining. Co-culture of MSCs with chondrons enhanced ECM matrix production, as compared to chondrocyte or chondron only cultures. The ratio 50:50 co-culture of MSCs and chondrons resulted in the highest increase in GAG production (18.5 ± 0.54 pg/cell at day 1 and 11 ± 0.38 pg/cell at day 7 in 50:50 co-culture versus 16.8 ± 0.61 pg/cell at day 1 and 10 ± 0.45 pg/cell at day 7 in chondron monoculture). The co-culture of MSCs with chondrons appeared to decelerate the loss of the PCM as determined by collagen VI expression, whilst the expression of high-temperature requirement serine protease A1 (HtrA1) demonstrated an inverse relationship to that of the collagen VI. Together, this implies that MSCs directly or indirectly inhibited HtrA1 activity and the co-culture of MSCs with chondrons enhanced ECM synthesis and the preservation of the PCM.

Population-based cohort study of variation in the use of emergency cholecystectomy for benign gallbladder diseases

Background

The aims of this prospective population-based cohort study were to identify the patient and hospital characteristics associated with emergency cholecystectomy, and the influences of these in determining variations between hospitals.

Methods

Data were collected for consecutive patients undergoing cholecystectomy in acute UK and Irish hospitals between 1 March and 1 May 2014. Potential explanatory variables influencing the performance of emergency cholecystectomy were analysed by means of multilevel, multivariable logistic regression modelling using a two-level hierarchical structure with patients (level 1) nested within hospitals (level 2).

Results

Data were collected on 4744 cholecystectomies from 165 hospitals. Increasing age, lower ASA fitness grade, biliary colic, the need for further imaging (magnetic retrograde cholangiopancreatography), endoscopic interventions (endoscopic retrograde cholangiopancreatography) and admission to a non-biliary centre significantly reduced the likelihood of an emergency cholecystectomy being performed. The multilevel model was used to calculate the probability of receiving an emergency cholecystectomy for a woman aged 40 years or over with an ASA grade of I or II and a BMI of at least 25·0 kg/m2, who presented with acute cholecystitis with an ultrasound scan showing a thick-walled gallbladder and a normal common bile duct. The mean predicted probability of receiving an emergency cholecystectomy was 0·52 (95 per cent c.i. 0·45 to 0·57). The predicted probabilities ranged from 0·02 to 0·95 across the 165 hospitals, demonstrating significant variation between hospitals.

Conclusion

Patients with similar characteristics presenting to different hospitals with acute gallbladder pathology do not receive comparable care.

Postoperative atrial fibrillation in liver transplantation

Postoperative atrial fibrillation (POAF) is common after major surgeries and is associated with increased morbidity and mortality. POAF after liver transplantation (LT) has not been reported. This study was undertaken to investigate the incidence, impact, and risk factors of POAF in LT patients. After IRB approval, LT between January 2006 and August 2013 at our center were retrospectively reviewed. POAF that occurred within 30 days after LT was included. Patients with and without POAF were compared and independent risk factors were identified by logistic regression. Of 1387 adults LT patients, 102 (7.4%) developed POAF during the study period. POAF was associated with significantly increased mortality, graft failure, acute kidney injury and prolonged hospital stay. Independent risk factors included age, body weight, MELD score, presence of previous history of AF, the vasopressors use prior to LT and pulmonary artery diastolic pressure at the end of LT surgery (odds ratios 2.0-7.2, all p < 0.05). A risk index of POAF was developed and patients with the high-risk index had more than 60% chance of developing POAF. These findings may be used to stratify patients and to guide prophylaxis for POAF in the posttransplant period.

Liver transplantation in recipients receiving renal replacement therapy: outcomes analysis and the role of intraoperative hemodialysis

The Model for End-Stage Liver Disease (MELD) system has dramatically increased the number of recipients requiring pretransplant renal replacement therapy (RRT) prior to liver transplantation (LT). Factors affecting post-LT outcomes and the need for intraoperative RRT (IORRT) were analyzed in 500 consecutive recipients receiving pretransplant RRT, including comparisons among recipients not receiving IORRT (No-IORRT, n = 401), receiving planned IORRT (Pl-IORRT, n = 70), and receiving emergent, unplanned RRT after LT initiation (Em-IORRT, n = 29). Despite a median MELD of 39, overall 30-day, 1-, 3- and 5-year survivals were 93%, 75%, 68% and 65%, respectively. Em-IORRT recipients had significantly more intraoperative complications (arrhythmias, postreperfusion syndrome, coagulopathy) compared with both No-IORRT and Pl-IORRT and greater 30-day graft loss (28% vs. 10%, p = 0.004) and need for retransplantation (24% vs. 10%, p = 0.099) compared with No-IORRT. A risk score based on multivariate predictors of IORRT accurately identified recipients with chronic (sensitivity 84%, specificity 72%, concordance-statistic [c-statistic] 0.829) and acute (sensitivity 93%, specificity 61%, c-statistic 0.776) liver failure requiring IORRT. In this largest experience of LT in recipients receiving RRT, we report excellent survival and propose a practical model that accurately identifies recipients who may benefit from IORRT. For this select group, timely initiation of IORRT reduces intraoperative complications and improves posttransplant outcomes.

Right salpingo-ovarian and distal ileal entrapment within a paracaecal hernia presenting as acute appendicits

INTRODUCTION

Pericaecal hernias are a rare subgroup of internal abdominal hernias that present with abdominal pain and occasionally with features of bowel obstruction.

PRESENTATION OF CASE

A 72 year old female presented with a 24-h history of sharp, localised right iliac fossa pain, and no other symptoms. Clinical examination confirmed localised peritonism in the right iliac fossa. A tentative diagnosis of acute appendicitis was considered but in view of age a CT scan was performed. An area of abnormality in the right iliac fossa region was noted. At laparoscopy a macroscopically normal appendix and caecum was found. A smooth non-indentable mass in the lateral right iliac fossa contained loops of distal ileum, passing through a retro-caecal mesenteric defect consistent with a paraceacal hernia, with entrapment of the right ovary and fallopian tube. A right salpingectomy as performed and subsequent histopathological examination confirmed infarction of the fallopian tube.

DISCUSSION

Internal abdominal hernias are reported to have a post mortem incidence ranging between 0.2 and 0.9% of which only 10-15% are accounted for by pericaecal hernias. Types of pericaecal hernias include: ileocolic, retrocaecal, ileocaecal and paracaecal. These hernias are predisposed by the embryological development of the caecum retracting to the posterior abdominal wall and forming potential fossae.

CONCLUSION

This case highlights the need to consider a pericaecal hernia as a differential cause of right iliac fossa peritonism, and an indication for radiological imaging such as CT scan when the history is atypical for acute appendicitis.

Cognitive errors detected in anaesthesiology: a literature review and pilot study

BACKGROUND

Cognitive errors are thought-process errors, or thinking mistakes, which lead to incorrect diagnoses, treatments, or both. This psychology of decision-making has received little formal attention in anaesthesiology literature, although it is widely appreciated in other safety cultures, such as aviation, and other medical specialities. We sought to identify which types of cognitive errors are most important in anaesthesiology.

METHODS

This study consisted of two parts. First, we created a cognitive error catalogue specific to anaesthesiology practice using a literature review, modified Delphi method with experts, and a survey of academic faculty. In the second part, we observed for those cognitive errors during resident physician management of simulated anaesthesiology emergencies.

RESULTS

Of >30 described cognitive errors, the modified Delphi method yielded 14 key items experts felt were most important and prevalent in anaesthesiology practice (Table 1). Faculty survey responses narrowed this to a 'top 10' catalogue consisting of anchoring, availability bias, premature closure, feedback bias, framing effect, confirmation bias, omission bias, commission bias, overconfidence, and sunk costs (Table 2). Nine types of cognitive errors were selected for observation during simulated emergency management. Seven of those nine types of cognitive errors occurred in >50% of observed emergencies (Table 3).

CONCLUSIONS

Cognitive errors are thought to contribute significantly to medical mishaps. We identified cognitive errors specific to anaesthesiology practice. Understanding the key types of cognitive errors specific to anaesthesiology is the first step towards training in metacognition and de-biasing strategies, which may improve patient safety.

Analysis of sintered polymer scaffolds using concomitant synchrotron computed tomography and in situ mechanical testing

The mechanical behaviour of polymer scaffolds plays a vital role in their successful use in bone tissue engineering. The present study utilised novel sintered polymer scaffolds prepared using temperature-sensitive poly(DL-lactic acid-co-glycolic acid)/poly(ethylene glycol) particles. The microstructure of these scaffolds was monitored under compressive strain by image-guided failure assessment (IGFA), which combined synchrotron radiation computed tomography (SR CT) and in situ micro-compression. Three-dimensional CT data sets of scaffolds subjected to a strain rate of 0.01%/s illustrated particle movement within the scaffolds with no deformation or cracking. When compressed using a higher strain rate of 0.02%/s particle movement was more pronounced and cracks between sintered particles were observed. The results from this study demonstrate that IGFA based on simultaneous SR CT imaging and micro-compression testing is a useful tool for assessing structural and mechanical scaffold properties, leading to further insight into structure-function relationships in scaffolds for bone tissue engineering applications.

The expression and function of NKG2D molecule on intrahepatic CD8+ T cells in chronic viral hepatitis

The natural killer (NK) cell receptor, NKG2D is a member of the c-type lectin-activating receptor family. It is expressed by all NK cells and by a sub-population of CD8+ T cells. NKG2D engagement with its ligands directly activates NK cells and acts as a co-stimulator on CD8+ T cells. Recent reports, however, have demonstrated a role for NKG2D in direct T-cell activation in chronic inflammation. The aim of this study was to investigate the pattern of expression and the functional role of NKG2D on circulating and intrahepatic CD8+ T cells in chronic viral hepatitis. Peripheral blood lymphocytes and intrahepatic lymphocytes from 45 patients with chronic viral hepatitis (HBV and HCV) were studied. Phenotypic NKG2D expression and its functional ability to activate intrahepatic and circulating lymphocytes were analysed. Intrahepatic CD8+ T cells display increased NKG2D expression in chronic viral hepatitis in comparison with circulating CD8+ T cells. NKG2D co-stimulates intrahepatic CD8+ T cells and hepatitis B virus-specific CD8+ T cells. However, we could not demonstrate an ability to directly activate CD8+ T cells through the NKG2D signalling pathway alone. NKG2D is up-regulated on intrahepatic CD8+ T cells in type B and C chronic viral hepatitis; however, its function appears to be restricted to that of a co-stimulatory molecule.

Classification tool for the systematic histological assessment of hepatocellular carcinoma, macroregenerative nodules, and dysplastic nodules in cirrhotic liver

AIM: To design a classification tool for the histological assessment of hepatocellular carcinoma (HCC), dysplastic nodules (DN), and macroregenerative nodules (MRN) in cirrhotic liver.

METHODS: Two hundred and twelve hepatocellular nodules (106 HCC; 74 MRN; 32 DN) were assessed systematically, quantitatively, and semiquantitatively as appropriate for 10 histological features that have been described as helpful in distinguishing small HCC, DN, and MRN in cirrhotic livers. The data were analyzed by multiple correspondence analysis (MCA).

RESULTS: MCA distributed HCC, DN, and MRN as defined by traditional histological evaluation as well as the individual histological variables, in a “malignancy scale”. Based on the MCA data representation, we created a classification tool, which categorizes an individual nodular lesion as MRN, DN, or HCC based on the balance of all histological features (i.e., vascular invasion, capsular invasion, tumor necrosis, tumor heterogeneity, reticulin loss, capillarization of sinusoids, trabecular thickness, nuclear atypia, and mitotic activity). The classification tool classified most (83%) of a validation set of 47 nodules in the same way as the routine histological assessment. No discrepancies were present for DN and MRN between the routine histological assignment and the classification tool. Of 25 HCC assigned by routine assessment in the validation set, 8 were assigned to the DN category by the classification tool.

CONCLUSION: We have designed a classification tool for the histological assessment of HCC and its putative precursors in cirrhotic liver. Application of this tool systematically records histological features of diagnostic importance in the evaluation of small HCC.

A distinct subset of chemokines dominates the mucosal chemokine response in inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) is characterised by intense mucosal recruitment of activated leukocytes. Chemokines determine inflammatory leukocyte recruitment and retention.

AIM

To compare expression of the entire chemokine family within colonic mucosa from IBD patients and uninflamed controls.

METHODS

A microarray of cDNAs, representing every member of this superfamily and their cognate receptors, was hybridised with probes derived from colonoscopic biopsies.

RESULTS

A distinct subset of chemokines, consisting of CXCLs 1-3 and 8 and CCL20, was upregulated in active colonic IBD, compared with uninflamed areas or tissue from controls. Increased expression of their cognate receptors, CXCR1, CXCR2 and CCR6, was confirmed by quantitative PCR and immunohistochemistry. An identical chemokine response was induced in Caco-2 cells by stimulation with interleukin (IL)-1beta, but not tumour necrosis factor-alpha (TNF-alpha). By contrast, IL-1beta and TNF-alpha were synergistic in an HT29 cell line and primary keratinocytes.

CONCLUSIONS

IL-1beta and TNF-alpha appear to be the pivotal mediators of a previously unidentified coordinated epithelial chemokine response that dominates the mucosal chemokine environment in inflamed IBD tissue.

Effect of gastrin and anti-gastrin antibodies on proliferation of hepatocyte cell lines

Gastrin (G-17) and its precursor glycine-extended gastrin (G-17-gly) have been shown to be trophic to some gastrointestinal tumors. This in vitro study assessed the effect of G-17, G-17-gly, anti-gastrin antibodies (anti-G-17), and the CCK-B receptor antagonist PD135,158 on three hepatoma cell lines (PLC/PRF/5, HepG2 and MCA-RH7777) and an embryonic liver cell line (WRL68). The pancreatic adenocarcinoma cell line AR42J was used as a positive control. G-17 and G-17-gly caused significant proliferation of AR42J and WRL68 cell lines. G-17-gly but not G-17 induced significant proliferation of the PLC/PRF/5 cell line. Anti-G-17 and PD135,158 significantly inhibited unstimulated AR42J and WRL68 cell lines. Anti-G-17 also inhibited the proliferative effects of G-17 and G-17-gly on AR42J, WRL68, and PLC/PRF/5 cell lines, whereas PD135,158 inhibited the proliferative effect of G-17 only. G-17 and G-17-gly as well as anti-G-17 and PD135,158 had no effect on HepG2 and MCA-RH77777 cell lines. It is concluded that G-17-stimulated proliferation is mediated via the CCK-B receptor and G-17-gly via a separate, as yet uncharacterized, receptor. There may therefore be a role for gastrin in embryonic hepatocellular proliferation and perhaps also in the proliferation of some hepatocellular tumors.

Laminar differences in recurrent excitatory transmission in the rat entorhinal cortex in vitro

Paired intracellular recordings were used to investigate recurrent excitatory transmission in layers II, III and V of the rat entorhinal cortex in vitro. There was a relatively high probability of finding a recurrent connection between pairs of pyramidal neurons in both layer V (around 12%) and layer III (around 9%). In complete contrast, we have failed to find any recurrent synaptic connections between principal neurons in layer II, and this may be an important factor in the relative resistance of this layer in generating synchronized epileptiform activity. In general, recurrent excitatory postsynaptic potentials in layers III and V of the entorhinal cortex had similar properties to those recorded in other cortical areas, although the probabilities of connection are among the highest reported. Recurrent excitatory postsynaptic potentials recorded in layer V were smaller with faster rise times than those recorded in layer III. In both layers, the recurrent potentials were mediated by glutamate primarily acting at alpha-amino-3-hydroxy-5-methyl-4-isoxazole receptors, although there appeared to be a slow component mediated by N-methyl-D-aspartate receptors. In layer III, recurrent transmission failed on about 30% of presynaptic action potentials evoked at 0.2Hz. This failure rate increased markedly with increasing (2, 3Hz) frequency of activation. In layer V the failure rate at low frequency was less (19%), and although it increased at higher frequencies this effect was less pronounced than in layer III. Finally, in layer III, there was evidence for a relatively high probability of electrical coupling between pyramidal neurons. We have previously suggested that layers IV/V of the entorhinal cortex readily generate synchronized epileptiform discharges, whereas layer II is relatively resistant to seizure generation. The present demonstration that recurrent excitatory connections are widespread in layer V but not layer II could support this proposal. The relatively high degree of recurrent connections and electrical coupling between layer III cells may be a factor in it's susceptibility to neurodegeneration during chronic epileptic conditions.

Quantitation of HCV RNA in liver of patients with chronic hepatitis C

BACKGROUND/AIMS

Liver HCV RNA has been quantitated in few studies and the feasibility and the role of this parameter in the evaluation of patients with chronic HCV hepatitis still warrant study. Our aim was to determine the concentrations of HCV RNA in the liver of chronic HCV patients and to correlate the results with serum viral load. We also studied the relation of levels of HCV RNA in the liver with serum aminotransferases levels and with the presence of cirrhosis.

METHODS

Twenty patients (14 males, aged 28 to 61 years) were studied. Twelve were infected by HCV type 1, six by type 3 and one by type 5. Percutaneous liver biopsy samples were obtained from 14 patients, and the remainder from liver explant in patients undergoing OLT. Twelve had chronic hepatitis and eight cirrhosis. HCV RNA levels were determined by bDNA.

RESULTS

HCV RNA levels below the detection limit were found in one liver and in five serum samples. HCV RNA (mean +/- SD) was 2.1 x 10(8) +/- 2.2 x 10(8) Eq/gm in the liver and 94 x 10(5) +/- 93 x 10(5) Eq/mL in serum, with a significant correlation between these values (r = 0.89; P < 0.0001). Serum HCV RNA levels were significantly lower (P = 0.001) in cirrhotic than in chronic hepatitis patients, while the groups did not differ in liver HCV RNA levels. No correlation was observed between liver or serum HCV RNA and serum ALT or AST.

CONCLUSIONS

Quantitation of HCV RNA is possible even in small liver samples. Although average levels are more than one log higher than those observed in serum, hepatic concentrations correlate with those observed in serum. The application of this technology to monitoring antiviral therapy and understanding the pathogenesis of the disease remains to be determined.

Expression and processing of gastrin in pancreatic adenocarcinoma

BACKGROUND

Gastrin is a trophic hormone and promotes growth of gastrointestinal and non-gastrointestinal cancers. Studies both in vitro and in vivo have suggested that pancreatic cancer cells not only have the ability to respond to circulating forms of gastrin but also to respond to the autocrine production of gastrin and its precursors. The aim of this study was to identify the expression of CCK-B/gastrin receptor, progastrin, glycine-extended gastrin and amidated gastrin in both normal pancreas and pancreatic adenocarcinoma.

METHODS

Tissue sections from patients with normal pancreas (n = 10) and pancreatic cancer (n = 22) were assessed using immunohistochemical methods for CCK-B/gastrin receptor, progastrin, glycine-extended gastrin and amidated gastrin expression.

RESULTS

Normal pancreas showed no expression of receptor or gastrin isoforms except for occasional cells in the islets. Definite expression of CCK-B/gastrin receptor, progastrin, glycine-extended gastrin and amidated gastrin was observed in 95, 91, 55 and 23 per cent of sections from patients with pancreatic cancer respectively.

CONCLUSION

Pancreatic cancer cells express CCK-B/gastrin receptor and gastrin precursor forms in most patients. Expression of the gastrin precursor forms is probably related to autocrine production. New therapeutic strategies need to be developed for the management of pancreatic cancer. Targeting gastrin and its receptor may provide a novel treatment option.

Intact mitochondrial electron transport function is essential for signalling by hydrogen peroxide in cardiac myocytes

Oxidative stress has been proposed as a mediator of cardiac injury during ischemia and reperfusion. We examined the signalling events initiated by short-term exposure of cardiac myocytes to oxidative stress elicited by hydrogen peroxide. A potent stimulation of tyrosine phosphorylation was observed within 1 to 2 min exposure to 1 m m hydrogen peroxide. Within 5 min, the ERK mitogen-activated protein kinases (ERK MAPKs) were activated. This activation of ERK MAPKs was blocked by N-acetylcysteine (NAC), implicating a role for free radicals in the signalling events. NAC failed to inhibit ERK MAPK activation by the hypertrophic agent, phenylephrine, or hyperosmotic shock. Myxothiazol, an inhibitor of complex III of the mitochondrial electron transport chain, also inhibited ERK MAPK activation by hydrogen peroxide, but not by 12- O -tetradecanoylphorbol-13-acetate (TPA) or hyperosmotic shock. Myxothiazol completely inhibited the increase in tyrosine phosphorylated proteins observed with hydrogen peroxide treatment. A variety of inhibitors which act at different levels of the mitochondrial electron transport chain (rotenone, theonyltrifluoroacetone, antimycin A, cyanide) also inhibited activation of the ERK MAPKs by hydrogen peroxide but not TPA or hyperosmotic shock. These studies suggest a novel mechanism of regulation of the ERK MAPK pathway and oxidative stress signalling by hydrogen peroxide.

Expression and processing of gastrin in pancreatic adenocarcinoma

BACKGROUND

Gastrin is a trophic hormone and promotes growth of gastrointestinal and non-gastrointestinal cancers. Studies both in vitro and in vivo have suggested that pancreatic cancer cells not only have the ability to respond to circulating forms of gastrin but also to respond to the autocrine production of gastrin and its precursors. The aim of this study was to identify the expression of CCK-B/gastrin receptor, progastrin, glycine-extended gastrin and amidated gastrin in both normal pancreas and pancreatic adenocarcinoma.

METHODS

Tissue sections from patients with normal pancreas (n = 10) and pancreatic cancer (n = 22) were assessed using immunohistochemical methods for CCK-B/gastrin receptor, progastrin, glycine-extended gastrin and amidated gastrin expression.

RESULTS

Normal pancreas showed no expression of receptor or gastrin isoforms except for occasional cells in the islets. Definite expression of CCK-B/gastrin receptor, progastrin, glycine-extended gastrin and amidated gastrin was observed in 95, 91, 55 and 23 per cent of sections from patients with pancreatic cancer respectively.

CONCLUSION

Pancreatic cancer cells express CCK-B/gastrin receptor and gastrin precursor forms in most patients. Expression of the gastrin precursor forms is probably related to autocrine production. New therapeutic strategies need to be developed for the management of pancreatic cancer. Targeting gastrin and its receptor may provide a novel treatment option.

Expression and processing of gastrin in pancreatic adenocarcinoma

BACKGROUND

Gastrin is a trophic hormone and promotes growth of gastrointestinal and non-gastrointestinal cancers. Studies both in vitro and in vivo have suggested that pancreatic cancer cells not only have the ability to respond to circulating forms of gastrin but also to respond to the autocrine production of gastrin and its precursors. The aim of this study was to identify the expression of CCK-B/gastrin receptor, progastrin, glycine-extended gastrin and amidated gastrin in both normal pancreas and pancreatic adenocarcinoma.

METHODS

Tissue sections from patients with normal pancreas (n = 10) and pancreatic cancer (n = 22) were assessed using immunohistochemical methods for CCK-B/gastrin receptor, progastrin, glycine-extended gastrin and amidated gastrin expression.

RESULTS

Normal pancreas showed no expression of receptor or gastrin isoforms except for occasional cells in the islets. Definite expression of CCK-B/gastrin receptor, progastrin, glycine-extended gastrin and amidated gastrin was observed in 95, 91, 55 and 23 per cent of sections from patients with pancreatic cancer respectively.

CONCLUSION

Pancreatic cancer cells express CCK-B/gastrin receptor and gastrin precursor forms in most patients. Expression of the gastrin precursor forms is probably related to autocrine production. New therapeutic strategies need to be developed for the management of pancreatic cancer. Targeting gastrin and its receptor may provide a novel treatment option.

Lamivudine and alpha interferon combination treatment of patients with chronic hepatitis B infection: a randomised trial

BACKGROUND, AIM, AND METHODS: Alpha interferon is the generally approved therapy for HBe antigen positive patients with chronic hepatitis B, but its efficacy is limited. Lamivudine is a new oral nucleoside analogue which potently inhibits hepatitis B virus (HBV) DNA replication. To investigate the possibility of an additive effect of interferon-lamivudine combination therapy compared with interferon or lamivudine monotherapy, we conducted a randomised controlled trial in 230 predominantly Caucasian patients with hepatitis B e antigen (HBeAg) and HBV DNA positive chronic hepatitis B. Previously untreated patients were randomised to receive: combination therapy of lamivudine 100 mg daily with alpha interferon 10 million units three times weekly for 16 weeks after pretreatment with lamivudine for eight weeks (n=75); alpha interferon 10 million units three times weekly for 16 weeks (n=69); or lamivudine 100 mg daily for 52 weeks (n=82). The primary efficacy end point was the HBeAg seroconversion rate at week 52 (loss of HBeAg, development of antibodies to HBeAg and undetectable HBV DNA).

RESULTS

The HBeAg seroconversion rate at week 52 was 29% for the combination therapy, 19% for interferon monotherapy, and 18% for lamivudine monotherapy (p=0.12 and p=0.10, respectively, for comparison of the combination therapy with interferon or lamivudine monotherapy). The HBeAg seroconversion rates at week 52 for the combination therapy and lamivudine monotherapy were significantly different in the per protocol analysis (36% (20/56) v 19% (13/70), respectively; p=0.02). The effect of combining lamivudine and interferon appeared to be most useful in patients with moderately elevated alanine aminotransferase levels at baseline. Adverse events with the combination therapy were similar to interferon monotherapy; patients receiving lamivudine monotherapy had significantly fewer adverse events.

CONCLUSIONS

HBeAg seroconversion rates at one year were similar for lamivudine monotherapy (52 weeks) and standard alpha interferon therapy (16 weeks). The combination of lamivudine and interferon appeared to increase the HBeAg seroconversion rate, particularly in patients with moderately elevated baseline aminotransferase levels. The potential benefit of combining lamivudine and interferon should be investigated further in studies with different regimens of combination therapy.

Reciprocal modulation of glutamate and GABA release may underlie the anticonvulsant effect of phenytoin

Although conventional wisdom suggests that the effectiveness of phenytoin as an anticonvulsant is due to blockade of Na+-channels this is unlikely to be it's sole mechanism of action. In the present paper we examined the effects of phenytoin on evoked and spontaneous transmission at excitatory (glutamate) and inhibitory (GABA) synapses, in the rat entorhinal cortex in vitro. Evoked excitatory postsynaptic potentials at glutamate synapses exhibited frequency-dependent enhancement, and phenytoin reduced this enhancement without altering responses evoked at low frequency. In whole-cell patch-clamp recordings the frequency of excitatory postsynaptic currents resulting from the spontaneous release of glutamate was reduced by phenytoin, with no change in amplitude, rise time or decay time. Similar effects were seen on miniature excitatory postsynaptic currents, recorded in the presence of tetrodotoxin. Evoked inhibitory postsynaptic potentials at GABA synapses displayed a frequency-dependent decrease in amplitude. Phenytoin caused a reduction in this decrement without affecting the responses evoked at low frequency. The frequency of spontaneous GABA-mediated inhibitory postsynaptic currents, recorded in whole-cell patch mode, was increased by phenytoin, and this was accompanied by the appearance of much larger amplitude events. The effect of phenytoin on the frequency of inhibitory postsynaptic currents persisted in the presence of tetrodotoxin, but the change in amplitude distribution largely disappeared. These results demonstrate for the first time that phenytoin can cause a simultaneous reduction in synaptic excitation and an increase in inhibition in cortical networks. The shift in balance in favour of inhibition could be a major factor in the anticonvulsant action of phenytoin.

Expression and processing of gastrin in hepatocellular carcinoma, fibrolamellar carcinoma and cholangiocarcinoma

BACKGROUND/AIMS

Gastrin is a trophic factor within the normal gastrointestinal tract and is also a mitogen for a number of gastrointestinal and non-gastrointestinal tumours. Precursor forms of gastrin including progastrin (proG) and glycine-extended gastrin (G-gly) as well as the fully processed amidated gastrin (G-NH2) are expressed by tumours. There has been little study of the role of gastrin in either normal liver or liver tumours. The aim of this study was to identify the expression of CCK-B/gastrin receptor (CCK-BR), proG, G-gly and G-NH2 in normal liver and liver tumours.

METHODS

Tissue sections from patients with hepatocellular carcinoma, fibrolamellar carcinoma, cholangiocarcinoma as well as normal liver biopsies were assessed for expression of CCK-BR and gastrin isoforms.

RESULTS

Most liver tumours express CCK-BR and are able to process gastrin as far as proG and G-gly, although not as far as the amidated form. There appears to be little expression of the receptor and no expression of precursor forms of gastrin in normal liver.

CONCLUSIONS

Liver tumours express the CCK-BR and precursor forms of gastrin. This expression may be associated with tumour proliferation.

Ribavirin treatment for patients with chronic hepatitis C: results of a placebo-controlled study

BACKGROUND/AIMS

Small, uncontrolled studies of ribavirin for patients with chronic hepatitis C have reported efficacy in chronic hepatitis C. We have evaluated the efficacy and safety of a 24-week course of oral ribavirin in patients with chronic hepatitis C, compared to placebo.

METHODS

A total of 114 patients were randomised to ribavirin or placebo. Ribavirin was administered in doses of 1000 or 1200 mg/day for 24 weeks. Efficacy was determined in the intention-to-treat population: 76 received ribavirin and 38 placebo.

RESULTS

Ribavirin was significantly more effective than placebo in reducing and normalising serum ALT levels: 42/76 (55%) of ribavirin-treated patients vs 2/38 (5%) placebo recipients had either normalisation of the ALT levels or a reduction from baseline of at least 50% (p < 0.001). ALT levels were normal in 22/76 (29%) of ribavirin-treated patients vs 0/38 placebo recipients (p < 0.001). Twenty-four weeks after stopping ribavirin, the majority of patients had abnormal ALT levels. There was no difference between the treatment groups in reduction or disappearance of HCV-RNA levels. HCV RNA disappeared during treatment in 3% of ribavirin-treated patients and 3% of placebo recipients. More ribavirin than placebo patients showed improvement in total Knodell score (45% vs 31%), but these differences were not statistically significant. Analysis of each component of a histology activity index revealed no statistically significant differences between treatment groups. Ribavirin patients had fewer lymphoid aggregates than did placebo recipients at the post-treatment assessment (p = 0.05). Ribavirin was associated with reversible haemolytic anaemia: a fall in haemoglobin occurred in 3% of placebo- and 32% (25/78) of ribavirin-treated patients, respectively (p < 0.001).

CONCLUSIONS

These data indicate that ribavirin was no more effective than placebo in reducing or eliminating HCV-RNA levels, and was not significantly more effective than placebo in improving hepatic histology after 6 months of treatment. The role of a 6-month treatment of chronic hepatitis C with ribavirin alone, without a significant effect on HCV RNA, is therefore limited.

Chronic ecstasy (3,4-methylenedioxymetamphetamine) abuse: a recurrent and unpredictable cause of severe acute hepatitis

Fifteen reports of hepatitis induced by ecstasy (MDMA, 3,4-methylenedioxymetamphetamine) have been published over the last 3 years. With the increasing enthusiasm for "Rave" parties, the incidence appears to be increasing, and is an important and often concealed cause of acute hepatitis in young people. We report two cases of recurrent ecstasy-associated hepatitis where the interval between drug consumption and jaundice was variable and the link therefore initially obscured. Liver biopsies of both patients showed acute hepatitis. One was of relatively mild degree, and the other was severe, with features suggesting auto-immune hepatitis. Both cases resolved spontaneously. A high index of suspicion and careful specific enquiry are necessary to make the diagnosis and warn the patient to abstain in future, since subsequent attacks may be fatal and insidious chronic damage may occur.

Pathways controlling the superoxide response during phagocyte differentiation: involvement of arachidonic acid and Ca2+ in the response to bacterial endotoxin

In contrast to the phorbol ester oxidative response, which only develops during dimethylsulphoxide (DMSO)-induced differentiation of the human leukemic myeloblast HL-60 cell-line, the endotoxin response was observed in undifferentiated and differentiated cells. The Ca2+ response to endotoxin, detected in both differentiated and undifferentiated HL-60 cells, consisted of a transient 10-50 nM increase in intracellular Ca2+. A very slow, irreversible increase in intracellular Ca2+ was detected at high 1-100 micrograms/ml endotoxin concentrations, and this effect, and the inositol phosphate response, correlated with the surfactant activities of various endotoxins and Lipid A. Arachidonic acid and sodium arachidonate 1-50 microM stimulated a large 200-500 nM and transient Ca2+ response in undifferentiated HL-60 cells, which was significantly greater than that elicited by 1-50 microM eicosapentaenoic acid, and was not observed at similar concentrations of arachidonic acid methyl ester or myristic acid. These concentrations (1-50 microM) of arachidonic acid were observed to have surfactant activities on the plasma membrane. At lower arachidonic acid concentrations a marked potentiation of both Ca2+ and oxidative responses to the chemotactic peptide fMet-Leu-Phe was detected. It is possible that the arachidonic acid released during phospholipase A2 activation of neutrophils may be involved in cellular cross-talk and, at higher concentrations, in directly activating Ca2+ and superoxide production. It is also possible that previously reported effects of endotoxin at high concentrations are an in vitro artefact of surfactant properties of endotoxin.

Differences in the tumor DNA analysis of a hepatocellular-carcinoma and a synchronous fibrolamellar variant

A 60 year old man had two tumours resected from his liver which were shown histologically to be a well differentiated hepatocellular carcinoma and the fibrolamellar variant. Both are considered clinically distinct and of different pathogenesis and have not been previously reported occurring synchronously. DNA analysis revealed allele loss on chromosome 12 in the hepatocellular carcinoma which was not found in the fibrolamellar variant. This finding may suggest that hepatocellular carcinoma and fibrolamellar variant may have different molecular-genetic mechanisms for the development, in addition to their clinico-pathological difference.

Epithelial changes following bone marrow transplantation: cytological atypia and epithelial endocrine cells

This report describes the histological and immunocytochemical findings in gastrointestinal biopsies and skin of a patient with chronic granulocytic leukaemia which progressed to blastic transformation, who was then treated with chemotherapy and total body irradiation followed by allogeneic bone marrow transplantation. The gut showed endocrine cells in the lamina propria and these had an immunophenotype similar to the glandular epithelium at the sites studied (stomach, duodenum and rectum), supporting the idea that the endocrine cells of the gut are more resistant to the effect of radiation, chemotherapy and graft-versus-host disease (GVHD) than are other cell types in the epithelium, and that lamina proprial endocrine cells are epithelially derived in this situation. Epidermis and gut epithelium also showed marked atypia due to the conditioning regimen and GVHD, and this case illustrates the possibility of misdiagnosis of carcinoma in this increasingly common situation. An additional, unusual feature of this case was the presence of a B-cell UCHL1 + ve lymphoma of the colon at autopsy, 122 days post-transplantation.