Regional variation in gene expression in the healthy colon is dysregulated in ulcerative colitis.

OBJECTIVE: To investigate differential intestinal gene expression in patients with ulcerative colitis and in controls. DESIGN: Genome-wide expression study (41,058 expression sequence tags, 215 biopsies). SETTING: Western General Hospital, Edinburgh, UK, and Genentech, San Francisco, USA. PATIENTS: 67 patients with ulcerative colitis and 31 control subjects (23 normal subjects and 8 patients with inflamed non-inflammatory bowel disease biopsies). INTERVENTIONS: Paired endoscopic biopsies were taken from 5 specific anatomical locations for RNA extraction and histology. The Agilent microarray platform was used and confirmation of results was undertaken by real time polymerase chain reaction and immunohistochemistry. RESULTS: In healthy control biopsies, cluster analysis showed differences in gene expression between the right and left colon. (chi(2) = 25.1, p<0.0001). Developmental genes, homeobox protein A13 (HOXA13), (p = 2.3x10(-16)), HOXB13 (p<1x10(-45)), glioma-associated oncogene 1 (GLI1) (p = 4.0x10(-24)), and GLI3 (p = 2.1x10(-28)) primarily drove this separation. When all ulcerative colitis biopsies and control biopsies were compared, 143 sequences had a fold change of >1.5 in the ulcerative colitis biopsies (0.01>p>10(-45)) and 54 sequences had a fold change of <-1.5 (0.01>p>10(-20)). Differentially upregulated genes in ulcerative colitis included serum amyloid A1 (SAA1) (p<10(-45)) the alpha defensins 5 and 6 (DEFA5 and 6) (p = 0.00003 and p = 6.95x10(-7), respectively), matrix metalloproteinase 3 (MMP3) (p = 5.6x10(-10)) and MMP7 (p = 2.3x10(-7)). Increased DEFA5 and 6 expression was further characterised to Paneth cell metaplasia by immunohistochemistry and in situ hybridisation. Sub-analysis of the inflammatory bowel disease 2 (IBD2) and IBD5 loci, and the ATP-binding cassette (ABC) transporter genes revealed a number of differentially regulated genes in the ulcerative colitis biopsies. CONCLUSIONS: Key findings are the expression gradient in the healthy adult colon and the involvement of novel gene families, as well as established candidate genes in the pathogenesis of ulcerative colitis.

Age-related variation in circadian rhythms of mitosis in the adrenal cortex of the male rat.

Using a metaphase arrest technique, mitotic activity was quantified in the adrenal cortex over a 24-h period in 14-day-old male Sprague-Dawley rats before functional rhythmicity of the hypothalamic pituitary-adrenal (HPA) axis is established, and after its onset, in 6- to 7-week-old rats. At all times, proliferative activity was greater in the younger animals, as previously reported. A significant circadian rhythm was identified in both groups, but the timing of the peak differed, lying between 17.00 and 21.00 h at 14 days and 11.00 and 15.00 h at 6-7 weeks. These results raise the possibility that functional rhythmicity of the HPA axis may alter an inherent proliferative rhythm.

Dietary calcium supplementation increases apoptosis in the distal murine colonic epithelium.

BACKGROUND: Increased dietary calcium might reduce colorectal cancer risk, possibly by reduction of colonic epithelial hyperproliferation, but not all studies have demonstrated this. Little is known about the effects of calcium on colonic apoptosis. AIM: To quantify the effects of increasing calcium on apoptosis and cell proliferation in normal murine colonic crypt epithelium. METHODS: Twenty one day old male C57B1/6 mice were fed either control AIN-76 diet (0.5% calcium wt/wt; n = 10) or the same supplemented with calcium carbonate (1.0% calcium; n = 10) for 12 weeks. Apoptotic cells in proximal and distal segments were counted and expressed as an apoptotic index (AI: frequency of apoptosis/100 longitudinal crypts). The bromodeoxyuridine (BrdU) labelling index was also determined. Differences were analysed by the student's t test. RESULTS: In control animals, the AI was significantly higher in the caecum/proximal colon (mean, 28.6; SEM, 2.0) compared with the distal colon (mean, 19.9; SEM, 1.8; p = 0.004). In the calcium treated group, the AI in the caecum/proximal colon (mean, 30.6; SEM, 1.7) was similar to controls (p = 0.71) but the AI in the distal colon was significantly greater (mean, 32.6; SEM, 1.8; p = 0.001) than in control mice and was raised to values similar to those in the proximal colon. Calcium was also associated with reduced crypt cellularity and, in the proximal colon, a downward shift in the crypt position at which apoptosis occurred. There were no significant differences in the BrdU labelling index between groups or between proximal and distal colonic segments in each group. CONCLUSIONS: Increased dietary calcium is associated with the induction of apoptosis in normal mouse distal colonic epithelium without affecting cell proliferation. This might contribute to its putative chemopreventive role in colorectal carcinogenesis. Whether this effect is direct or indirect requires further study.

Gastrin and colorectal cancer: where now?

Gastrin exerts a trophic influence on various regions of the gastrointestinal (GI) tract and this has led to an interest in its potential role in the growth of GI tumours. There is little evidence that elevated circulating levels of gastrin predispose to colonic tumours. However, the hormone can be detected within some colonic tumour tissues and a possible paracrine or autocrine role has been proposed. At present, evidence for such a role is conflicting, as is the evidence that colonic tumour cells possess receptors for the mature hormone. Colonic tumours have been found to contain much higher concentrations of incompletely processed gastrin precursors such as glycine extended gastrin and recent studies indicate that they may exert trophic effects mediated by specific receptors. Further studies of this are required. Whether specific hormone receptor antagonists will have a role in the clinical management of colonic tumours remains unclear.

Endoscopic surveillance practice for Barrett' s oesophagus in Scotland and early experience in implementing local guidelines.

Management of columnar lined oesophagus (CLO; Barrett s oesophagus) is controversial. We prospectively audited surveillance practices in Scotland and prospectively assessed the impact of introducing local guidelines for Barrett s surveillance in Edinburgh. Most respondents were gastroenterologists. The majority take random, not four quadrant, biopsies from the CLO. In Edinburgh during 2000, 80 patients underwent surveillance. The guideline protocol was not followed in 30 (37.5%) patients. Follow up of patients without dysplasia generally conformed to the guidelines. Follow up of patients with low grade dysplasia was highly variable while management of those with high grade dysplasia followed the guidelines. Overall we found a wide variability in the management and surveillance of CLO. Early experience suggests that implementation of guidelines is helpful but there is still variation in practice.

The safety profile of anti-tumour necrosis factor therapy in inflammatory bowel disease in clinical practice: analysis of 620 patient-years follow-up.

BACKGROUND: Anti-TNF agents are now widely used in Crohn's disease (CD), and in ulcerative colitis (UC). AIM: To review the safety profile of anti-TNF agents in all patients treated with infliximab in Edinburgh from 1999 to 2007. METHODS: Complete data were available on 202/207 patients comprising 157 CD, 42 UC and three coeliac disease. Median follow-up was 2.4 years (1.0-4.9) with a total of 620 patient-years follow-up. About 19.1% of CD patients were subsequently treated with adalimumab. RESULTS: Seven deaths (3.3%) occurred in follow-up; only one death was <1 year post-infliximab (at day 72, from lung cancer). A total of six malignancies (three haematological, three bronchogenic) and six cases of suspected demyelination (three with confirmed neurological disease) were reported. In the 90 days following infliximab, 95 adverse events (36 serious) occurred in 58/202 (28.7%) patients. In all, 42/202 (20.8%) had an infectious event (22 serious) and 27/202 (13.4%) of patients had an infusion reaction: 19 acute (four serious) and eight delayed (three serious). CONCLUSIONS: Serious infections, malignancies and neurological disease complicate anti-TNF use in clinical practice. Although evidence for causality is unclear, potential mechanisms and predisposing factors need to be explored. In individual patients, the risk/benefit analysis needs to be carefully assessed and discussed prior to commencement of therapy.

The use of adalimumab in the management of refractory Crohn's disease.

BACKGROUND: Adalimumab is a humanized monoclonal antibody targeting tumour necrosis factor-alpha. Recent clinical trials have demonstrated its efficacy in Crohn's disease; however, experience in clinical practice remains limited. AIM: To investigate the efficacy and safety of adalimumab in the clinical setting. METHODS: The clinical outcomes of patients with medically refractory Crohn's disease treated with adalimumab in the Western General Hospital Edinburgh, over a 3-year period (2003-2006), were studied. RESULTS: Twenty-two (14 females; age at therapy: 32.6 years) patients were treated using an 80/40 mg induction regimen followed by fortnightly 40 mg treatment. All had proven refractory/intolerant to corticosteroids and immunosuppression. Twenty patients had had previous infliximab infusions - of these eight (36%), six (27%), three (14%) had previous infusion reactions, no response and lost response to infliximab, respectively. Over a period of 1.0 years (IQR: 0.62-2.5), Kaplan-Meier analyses showed that 68% (seven nonresponders) were in clinical remission and 67% (five surgery - discounting oral CD) avoided further surgery for active disease. 59% required dose escalation to 40 mg weekly (0.55 years; IQR: 0.22-1.4). Three (50%) primary nonresponders to infliximab achieved remission. Two patients developed serious infective complications and one patient developed lung cancer. CONCLUSIONS: Adalimumab is efficacious in refractory Crohn's disease, with benefit observed in infliximab primary nonresponders. However, many patients require escalation of dosing regimen.

Endoscopic ultrasound in cancer staging.

BACKGROUND: Endoscopic ultrasound (EUS) represents one of the most significant developments in endoscopy over the past 20 years. It allows highly detailed assessment of the gastrointestinal wall layers as well as to visualize extraluminal structures such as the mediastium and retroperitoneum. METHODS: The literature was reviewed to assess the role of EUS in cancer staging. RESULTS: EUS is an integral part of the staging of many upper gastrointestinal cancers as well as rectal and lung cancer and has been shown to be cost-effective. It can be used to confirm malignancy in suspicious lesions as well as to identify and confirm nodal or metastatic spread. It has been used to re-stage cancers following chemoradiotherapy, but results are disappointing. Future developments are discussed, which may include using EUS-guided delivery of anti-tumour agents directly into tumours.

Endobronchial and endoscopic ultrasound-guided real-time fine-needle aspiration for mediastinal staging.

Accurate staging of the mediastinum in lung cancer is essential for optimising treatment strategies. Conventional transbronchial needle aspiration (TBNA) is a blind procedure, reliant upon prior computed tomography (CT) or ultrasound imaging, but has low sensitivity. The current study reports the initial experience of using a prototype endobronchial ultrasound (EBUS) probe that allows TBNA under real-time imaging. In 20 patients selected by CT scanning, a linear-array ultrasound bronchoscope was used to visualise paratracheal and hilar lymph nodes, and TBNA was performed under direct ultrasonic control. In seven cases, sequential endoscopic ultrasound (EUS) was used to assess postero-inferior mediastinal lymph nodes. All procedures were performed under conscious sedation. EBUS-TBNA was undertaken in 18 out of 20 cases and EUS-guided fine-needle aspiration in six out of seven cases. Cytology showed node (N)2/N3 disease in 11 out of 18 EBUS-TBNA cases and provided a primary diagnosis for eight patients. EBUS-TBNA cytology was negative in six cases, which was confirmed by mediastinoscopy or clinical follow-up in four. EUS provided additional information in all cases. There were no procedural complications. Sensitivity, specificity and accuracy for EBUS-TBNA were 85%, 100% and 89%, respectively. In conclusion, endobronchial ultrasound with real-time transbronchial needle aspiration offers improved sensitivity and accuracy for staging of the middle mediastinum, and, combined with endoscopic ultrasound, should allow investigation of the majority of the mediastinum.

Endoscopic ultrasonography (EUS) in the staging of malignancy.

Since first introduced over 20 years ago, endoscopic ultrasonography (EUS) has become established as an important tool in the staging of gastrointestinal malignancies and potentially resectable non-small cell lung cancer. This review describes the current roles of EUS in staging these tumours, highlighting interventional roles, current problem areas and future developments.

Compensatory adrenal growth in dexamethasone treated rats.

The changes in right adrenal weight and adrenocortical mitotic activity have been quantified in the early (up to 72 h) stages following left adrenalectomy or sham adrenalectomy in adult male Sprague Dawley rats. These have been compared with the changes seen in rats pretreated for 14 days with a daily intraperitoneal injection of the synthetic glucocorticoid, dexamethasone (200 micrograms/kg) body weight. The results indicate a significant proliferative response in both groups of animals, although basal proliferative activity and the amplitude of the response was lower in the dexamethasone treated animals. In addition, they suggest two waves of mitotic activity at 24 and 72 h.

Warfarin-induced skin necrosis.

Skin necrosis is a rare but serious side-effect of treatment with warfarin. At particular risk are those with various thrombophilic abnormalities, especially when warfarinization is undertaken rapidly with large loading doses of warfarin. With the increasing number of patients anticoagulated as out-patients for thromboprophylaxis, we are concerned that the incidence of skin necrosis may increase. If skin necrosis does occur, prompt remedial action may be of benefit in preventing permanent tissue damage.

Endoscopic ultrasonography in the diagnosis and management of suspected upper gastrointestinal submucosal tumours.

BACKGROUND: 'Submucosal' lesions in the upper gastrointestinal tract are often difficult to evaluate. Endoscopic ultrasonography (EUS) provides high-quality information about the nature of these lesions and may assist management. This study assessed the use of EUS in the evaluation and management of upper gastrointestinal submucosal tumours. METHODS: Forty-four consecutive patients were referred with suspected upper gastrointestinal submucosal lesions for EUS. All examinations were performed by one of two experienced endosonographers. RESULTS: Most patients were referred for EUS with a suspected gastrointestinal stromal tumour. The pre-EUS diagnosis did not correlate with the EUS diagnosis in 25 of 44 patients. Pathological correlation was possible in 16 patients, and the EUS diagnosis was confirmed in each case. Based on the findings at EUS, 12 patients underwent resection. Pathology confirmed the ultrasonographic findings in these patients. Follow-up EUS to monitor lesions was recommended in a further three patients. CONCLUSION: EUS is safe and provides useful information in many patients with suspected submucosal tumours. EUS may reveal unsuspected findings and can increase physician certainty, allowing accurate diagnosis and facilitation of the management process.

A randomized trial of thermal ablative therapy versus expandable metal stents in the palliative treatment of patients with esophageal carcinoma.

BACKGROUND: Expandable metal stent insertion and thermal tumor ablation (TTA) both improve dysphagia in patients with advanced esophageal cancer, but no direct comparison study of their efficacy on health-related quality of life has been published. The aim of this study was to compare survival, relief of dysphagia, quality of life, and cost in patients treated by thermal ablation or stent insertion. METHODS: Sixty-five patients with histologically proven, inoperable esophageal and esophagogastric cancer were initially assessed by endoscopy, barium contrast radiography, and CT of the thorax and abdomen. Dysphagia and quality of life were serially assessed at monthly intervals. Patients were randomized to either repeated TTA or insertion of an expandable metal stent. RESULTS: Median survival was significantly longer for patients who underwent TTA; 125 days (17-546) versus 68 days (8-602) for those in whom a stent was inserted (p < 0.05), although relief of dysphagia was disappointing in both groups. Several patients in both groups had serious treatment-related complications and required further therapy. Median length of hospital stay and cost were greater for patients treated by TTA. Health-related quality of life was globally impaired in both groups at randomization and deteriorated significantly in the stent group. Pain was reported more commonly by patients with stents. CONCLUSIONS: The palliation of patients with advanced esophageal and esophagogastric cancer remains unsatisfactory. Health-related quality of life deteriorated in the stent group but not in the TTA group. Patients treated by TTA live longer than patients treated by stent insertion, but the cost of TTA is higher.

Helicobacter pylori infection and abnormalities of acid secretion in patients with duodenal ulcer disease.

BACKGROUND & AIMS: The mechanism by which Helicobacter pylori predisposes to duodenal ulcers (DUs) remains unclear. The aim of this study was to investigate the effect of the infection on acid secretion. METHODS: Acid output was examined basally and in response to gastrin-releasing peptide (GRP) and gastrin in healthy volunteers with and without H. pylori infection and in patients with DUs before and after eradication of the infection. RESULTS: Compared with H. pylori-negative healthy volunteers, patients with DUs with H. pylori had the following abnormalities of acid secretion: (1) threefold increase in basal acid output, (2) sixfold increase in acid response to GRP, (3) increased maximal acid response to exogenous gastrin, (4) increased ratio of basal acid output to maximal gastrin-stimulated output, and (5) increased ratio of maximal GRP-stimulated acid output to maximal gastrin-stimulated output. All of these abnormalities resolved fully after H. pylori eradication except for increased maximal acid output to gastrin, which was unchanged. Infected healthy volunteers showed a threefold increase in acid response to GRP that resolved after eradication of H. pylori infection. CONCLUSIONS: These disturbances in acid secretion caused by H. pylori infection are consistent with impaired inhibitory control and are likely to be relevant to the mechanism by which the infection predisposes to DU.

Omeprazole inhibits colorectal carcinogenesis induced by azoxymethane in rats.

Numerous clinical and experimental studies suggest that gastrin plays an important part in the development of colorectal cancer in humans. This study was done to assess the influence of omeprazole induced hypergastrinaemia on the development of colorectal tumours in an experimental animal model. Forty female Sprague-Dawley rats received either omeprazole (40 mumol/kg) or vehicle (0.25% methylcellulose) by once daily oral gavage throughout the experiment. All animals received 12 consecutive weekly subcutaneous injections of azoxymethane (10 mg/kg/week) beginning at week 6. Serum gastrin concentrations were measured during weeks 1 and 5 and at death (week 27). Chronic omeprazole treatment resulted in appreciable hypergastrinaemia during the study, mean gastrin concentrations in omeprazole treated rats being raised by up to nine to 10 fold, compared with vehicle treated control rats (p < 0.001). Despite this, tumour incidence in the omeprazole group was significantly lower at 63%, compared with 95% in the vehicle only group (p < 0.02). The median number of tumours in the omeprazole group (1) compared with the vehicle group (3) was also significantly lower (p = 0.02). Average tumour size, site distribution, and the comparative frequencies of adenomas and adenocarcinomas were similar in the two groups. This study shows that omeprazole protects against colorectal carcinogenesis in this model despite causing appreciable hypergastrinaemia. The mechanism by which this occurs is unclear and merits further investigation. Because of the compounding protective effects of omeprazole, this model is not a suitable one for studying the longterm trophic effects of gastrin on the colon.

An assessment of the potential value of endoscopic ultrasound as a cost-minimizing tool in dyspeptic patients with persistent symptoms.

STUDY AIMS: To quantify resource utilization in dyspeptic patients with persistent symptoms and to determine whether using both the endoscopic and ultrasound capabilities of endoscopic ultrasound could reduce costs. METHODS: Consecutive patients with persistent dyspepsia, after a minimum 1-month trial of acid suppression, underwent endoscopic ultrasound (EUS) and upper endoscopy using the GF-UM20 echo endoscope. Assuming EUS could replace imaging tests which had been requested in addition to upper endoscopy, the hypothetical costs of the EUS-based and upper endoscopy-based strategies were compared. RESULTS: 116 patients with persistent dyspepsia underwent EUS, of whom 64.6 % had > or = 2 imaging procedures, most commonly computed tomography (CT) (70.6 %) and abdominal ultrasound (64.7 %). The number of tests did not correlate strongly with any demographic variables. The fiberoptic echo endoscope provided an adequate endoscopic and ultrasound examination but was damaged by retroflexion. Direct hospital costs were lowest for the EUS-based strategy. Total avoidable cost for 116 patients was $ 4137 to $ 14 121 (or $ 36 to $ 122 per patient), depending on whether upper endoscopy was performed in the non-EUS strategies. CONCLUSIONS: Patients with persistent dyspepsia may undergo multiple abdominal imaging procedures. Clinical variables do not predict the need for additional testing. An EUS-based strategy may reduce overall costs if it prevents additional testing.

EUS to detect evidence of pancreatic disease in patients with persistent or nonspecific dyspepsia.

BACKGROUND: Mild chronic pancreatitis is difficult to diagnose and the diagnosis is therefore not sought routinely in patients with dyspepsia. The aim of our study was to compare the prevalence of endosonographic pancreatic abnormalities in patients with dyspepsia and control subjects. METHODS: The number of endosonographic abnormalities was compared prospectively in patients with dyspepsia and control patients. Patients in whom there was any suspicion of pancreatic disease were analyzed separately. RESULTS: Between November 1998 and January 1999, 156 patients with dyspepsia were compared with 27 control patients. The groups were similar except that control patients were significantly older and more likely to be men. The mean number of endosonographic abnormalities was higher in dyspeptic patients than in control patients (mean number of abnormalities 3.3: 95% CI [2.9, 3.6] vs. 1.9: 95% CI [0.3, 1.7]). The strongest independent predictors of severe endosonographic abnormalities (defined as 5 or more abnormalities) were the presence of suspected pancreatic disease (odds ratio 7.29: 95% CI [2.03, 26. 14]) and dyspepsia (odds ratio 7.21: 95% CI [1.99, 26.26]). In the dyspepsia group, no clinical variables were significant predictors of severe abnormalities. However, most patients had nonspecific-type dyspepsia or persistent symptoms after therapeutic trials of acid suppression. CONCLUSIONS: Dyspepsia may be an atypical presentation of pancreatic disease in patients with persistent or nonspecific symptoms. Endosonography may be useful to screen for pancreatic disease in patients with persistent dyspepsia.