What is an intractable duodenal ulcer and how should it be managed?

An intractable duodenal ulcer is an ulcer that has not healed after 8 weeks of full-dose treatment with a modern anti-ulcer drug. Such ulcers are relatively rare--perhaps five in 100 patients will have intractable duodenal ulceration. The differential diagnosis includes non-compliance as a cause of continuing ulceration, hypersecretion of gastric acid or other rare causes of ulcers in the duodenum. Investigations should include biopsy of the continuing ulceration at endoscopy, measurement of fasting plasma gastrin and routine haematology and biochemistry profiles. An intractable duodenal ulcer can be treated either by using a powerful antisecretory regimen (high doses of ranitidine or famotidine or a conventional dose of omeprazole), by changing to tripotassium dicitrato bismuthate or, in exceptional circumstances, by extremely careful surgical intervention.

Degrees of acid suppression and ulcer healing: dosage considerations

The human stomach has a normal circadian rhythm of intragastric acidity characterized by increasing acidity during the day and peaks in the early hours of the morning. Eating causes a transient decrease of intragastric acidity. Acid appears to be the permissive factor in peptic ulcer disease and to be responsible for symptoms; the patient with duodenal ulcer may secrete too much acid. Pharmacological control of gastric acid secretion will speed ulcer healing. Modern regimens, which typically use a bedtime dose of an H2-receptor antagonist, produce a pulse of decreased acidity. Intragastric acidity is decreased during the night and early morning, leaving a normal profile of acidity during the day and early evening. Higher or more frequent doses of an antisecretory agent can produce a more profound decrease of 24-h intragastric acidity. Theoretical problems associated with a sustained or profound decrease of 24-h intragastric acidity include the threat of enteric infection and infestation, potential bacterial overgrowth with possible N-nitrosamine formation, and drug-induced hypergastrinaemia. In light of these potential problems, for the management of simple peptic ulceration, it appears sensible to use the minimum intervention required. Bedtime H2-receptor blockade is one such regimen. The more potent antisecretory regimens can be used for difficult clinical problems such as the Zollinger-Ellison syndrome, intractable duodenal ulceration, and severe oesophagitis.

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.

Medical outpatients: changes that can benefit patients

This article reviews the current literature relating to medical outpatient services. It has been produced as part of the RCP/NHS Confederation working party on outpatients departments. The article deals with surveys of patient views on outpatients, suggested ways of improving the service, and how best to accommodate teaching in this setting. An RCP booklet, 'How user friendly is your outpatient department?', has also been produced and is available from the college.

Prevalence of gastrointestinal diseases in two British national birth cohorts

BACKGROUND

Few studies have investigated the prevalence of multiple gastrointestinal diseases in the general British population.

AIM

To examine the prevalence of Crohn's disease (CD), ulcerative colitis (UC), irritable bowel syndrome (IBS), gall stones (GS), and peptic ulcer disease (PUD).

SUBJECTS

The 1970 British Cohort Study (BCS70) and the National Child Development Study (NCDS) are two one week national birth cohorts born in 1970 and 1958, respectively. All cohort members living in Great Britain were interviewed in 1999/2000.

METHODS

The prevalence rates of the five diseases were calculated, and associations with sex and childhood social class were investigated using logistic regression.

RESULTS

At age 30 years, the prevalence rates per 10,000 (95% confidence interval (CI)) in the 1970 and 1958 cohorts, respectively, were: CD 38 (26-49), 21 (13-30); UC 30 (20-41), 27 (18-37); IBS 826 (775-877), 290 (267-330); GS 88 (71-106), 78 (62-94); and PUD 244 (214-273), 229 (201-256). There was a significantly higher proportion with CD (p=0.023) and IBS (p=0.000) in the 1970 cohort compared with the 1958 cohort at age 30 years. Comparing the cohorts in the 1999/2000 sweep, UC, GS, and PUD were significantly (p=0.001, p=0.000, p=0.000) more common in the 1958 cohort. There was a statistically significant trend for a higher risk of GS with lower social class in both cohorts combined (p=0.027).

CONCLUSION

The study indicates an increasing temporal trend in the prevalence of CD and suggests a period effect in IBS, possibly due to adult life exposures or variation in recognition and diagnosis of IBS.

Eradication of Helicobacter pylori increases nocturnal intragastric acidity during dosing with rabeprazole, omeprazole, lansoprazole and placebo

BACKGROUND

The eradication of Helicobacter pylori decreases the antisecretory activity of omeprazole and lansoprazole. Rabeprazole is a potent proton pump inhibitor that may not be affected as greatly by H. pylori status.

AIM

To compare the effect of H. pylori eradication on intragastric acidity and plasma gastrin during dosing with lansoprazole, omeprazole, rabeprazole and placebo.

METHODS

Twenty-four healthy H. pylori-infected volunteers were studied on day 7 of dosing with placebo, lansoprazole 30 mg, omeprazole 20 mg and rabeprazole 20 mg, before and at least 5 weeks after H. pylori eradication. On each occasion, the 24-h intragastric acidity was measured by gastric aspiration. Plasma gastrin concentrations were measured hourly from 08.00 to 13.00 h.

RESULTS

Sixteen subjects completed the study. For all three drugs and placebo, H. pylori eradication increased intragastric acidity, particularly nocturnal acidity, and decreased plasma gastrin. There were no differences between the three drugs with respect to 24-h acidity, percentage of time pH > 4 or 5-h plasma gastrin, either before or after H. pylori eradication. Before eradication, the percentage nocturnal time at pH > 3 was significantly greater during rabeprazole than during lanso-prazole dosing.

CONCLUSIONS

The increase in intragastric acidity seen after H. pylori eradication during dosing with proton pump inhibitors is a drug-class effect, particularly affecting nocturnal acid control. This is related to increased spontaneous intragastric acidity after H. pylori eradication.

Siblings and the risk of inflammatory bowel disease

BACKGROUND

Environmental exposures in early life have been implicated in the aetiology of inflammatory bowel disease (IBD). Siblings are used as proxy markers to characterize patterns of exposure relevant to the risk of IBD.

METHODS

Some 15,823 patients with ulcerative colitis and 12,668 with Crohn disease from the Swedish In-patient Register were compared with 79,546 and 63,035 controls, respectively, in a case-control study. Multiple logistic regression was used to investigate associations with older and younger siblings, and adjustment was made for sex, year of birth, mother's age, region and, additionally, father's social class.

RESULTS

Older siblings are associated with a graded increased risk for ulcerative colitis (P for trend <0.001) and an adjusted odds ratio of 1.15 (95% CI 1.07-1.24) for three or more older siblings. Younger siblings are associated with a graded decreased risk for Crohn disease (P for trend <0.001) with an adjusted odds ratio of 0.83 (0.76-0.90) for three or more younger siblings. The greatest protective association with Crohn disease was seen for younger siblings born within 2 years of the subject. Older maternal age is independently associated with a decreased risk of Crohn disease, with P for trend <0.001. Additional adjustment for social class did not substantially alter the results.

CONCLUSIONS

Having siblings is associated with the risk and phenotype of developing IBD, possibly through their influence on patterns of antigenic exposure in early life. The association of maternal age with Crohn disease may reflect age-related changes in maternal immune profile.

Phase II study of anti-gastrin-17 antibodies, raised to G17DT, in advanced pancreatic cancer

PURPOSE

The prognosis for advanced pancreatic cancer remains poor. Gastrin acts as a growth factor for pancreatic cancer. We describe the first study of the antigastrin immunogen G17DT in pancreatic cancer. Our aims were to determine the antibody response, safety, tolerability, and preliminary evidence of efficacy of G17DT in advanced pancreatic cancer.

PATIENTS AND METHODS

Thirty patients with advanced pancreatic cancer were immunized with three doses of either 100 micro g or 250 micro g of G17DT.

RESULTS

In the whole group, 20 (67%) of 30 patients produced an antibody response. The 250- micro g dose resulted in a significantly greater response rate of 82% compared with 46% for the 100- micro g group (P =.018). The most significant side effects, seen in three patients, were local abscess and/or fever. The median survival for the whole group from the date of the first immunization was 187 days; median survival was 217 days for the antibody responders and 121 days for the antibody nonresponders. The difference in survival between the antibody responders and nonresponders was significant (P =.0023).

CONCLUSION

Patients with advanced pancreatic cancer are able to mount an adequate antibody response to G17DT. The 250- micro g dose is superior to the 100- micro g dose, and it appears to be generally well tolerated. Antibody responders demonstrate significantly greater survival than antibody nonresponders. Phase III studies are currently underway in order to determine efficacy.

A pilot study of treatment of active ulcerative colitis with natalizumab, a humanized monoclonal antibody to alpha-4 integrin

BACKGROUND

Alpha-4 integrins facilitate leucocyte migration across vascular endothelium.

AIM

To assess the safety and efficacy of natalizumab (Antegren), a humanized antibody to alpha-4 integrin, in patients with active ulcerative colitis.

METHODS

Ten patients with active ulcerative colitis, defined by a Powell-Tuck activity score > 4, received a single 3 mg/kg natalizumab infusion. The primary end-point was the change in Powell-Tuck score at 2 weeks post-infusion.

RESULTS

Significant decreases in the median Powell-Tuck score were observed at 2 and 4 weeks post-infusion (7.5 and 6, respectively) compared to the median baseline score (10). Five of 10 patients achieved a good clinical response at 2 weeks and one more patient by 4 weeks, defined by a Powell-Tuck score of < or = 5. Significant improvements in quality of life scores were found at week 4. Rescue medication was required by two (20%), three (30%) and eight (80%) patients by weeks 2, 4 and 8, respectively (median, 34 days; range, 8-43 days). One patient remained in remission at 12 weeks. The median C-reactive protein at 2 weeks (6 mg/L) was lower than that pre-treatment (16 mg/L).

CONCLUSIONS

A single 3 mg/kg infusion of natalizumab was well tolerated by ulcerative colitis patients. The positive efficacy demonstrated in this study merits further investigation by randomized, placebo-controlled trials.

Control of intragastric acidity with over-the-counter doses of ranitidine or famotidine

BACKGROUND

Histamine H2-receptor antagonists are available over the counter for the treatment of heartburn.

AIM

To compare the effects of low doses of ranitidine and famotidine on intragastric acidity in a three-way crossover study.

METHODS

Healthy subjects (12 male, 12 female) were dosed on three occasions with single oral doses of placebo, ranitidine, 75 mg, and famotidine, 10 mg, 1 h after lunch. The pH of gastric aspirates was then measured for 20 h. Subjects ate standard meals and snacks. Analysis of variance was used to determine the statistical significance of differences in acidity (mmol/L) during the day (12.30-22.30 hours) and night (22.30-08.30 hours).

RESULTS

Ranitidine and famotidine were superior (P < 0.05) to placebo in decreasing acidity for daytime and night-time intervals. There were no significant differences in mean gastric acidity between ranitidine and famotidine during the daytime (11.37 mmol/L vs. 13.42 mmol/L, respectively) and night-time (23.57 mmol/L vs. 24.74 mmol/L, respectively). Intragastric acidity after ranitidine was significantly lower than that after famotidine in the first 2.5-h period following dosing (4.32 mmol/L vs. 9.28 mmol/L; P < 0.05).

CONCLUSIONS

Lunchtime doses of ranitidine and famotidine decreased acidity during day- and night-time periods. The effect of ranitidine was significantly greater for the first 2.5 h after dosing.

Inflammatory bowel disease and laterality: is left handedness a risk?

BACKGROUND

Left handedness has been associated with inflammatory bowel disease (IBD) and autoimmune diseases.

AIMS

To determine whether left handedness is associated with IBD in two prospective national birth cohorts.

METHODS

Subjects with Crohn's disease (CD) and ulcerative colitis (UC) were identified from two national longitudinal birth cohorts at age 26 years (1970 British Cohort Study (BCS70), born in 1970) and age 33 years (National Child Development Study (NCDS), born in 1958). Laterality was determined at age 10 (BCS70) or seven (NCDS) years, based on hand preference for writing and foot preference for kicking a ball (BCS70 only). Multiple logistic regression was used to assess the relationship of handedness with CD, UC, and IBD in the cohorts combined and adjusted for sex.

RESULTS

Both cohorts combined showed increased adjusted relative odds of 2.13 (95% confidence interval (CI) 0.97--4.65; p=0.059), 2.13 (95% CI 0.92--4.91; p=0. 077), and 2.13 (95% CI 1.20--3.78; p=0.010) for CD, UC, and IBD, respectively in left handers.

CONCLUSIONS

The study suggests a link between IBD and left handedness which may be genetic and/or environmental in origin.

A randomized placebo-controlled trial of a humanized monoclonal antibody to alpha4 integrin in active Crohn's disease

BACKGROUND & AIMS

alpha4 integrins are important mediators of leukocyte migration across vascular endothelium. This pilot placebo-controlled study aimed to assess the safety and efficacy of natalizumab, a recombinant humanized monoclonal antibody to alpha4 integrin, in patients with mild to moderately active Crohn's disease.

METHODS

Thirty patients with active Crohn's disease (Crohn's Disease Activity Index [CDAI] > or =151 and < or =450) received a 3-mg/kg infusion of natalizumab (n = 18) or placebo (n = 12) by double-blind randomization. The study's primary endpoint was change in CDAI at week 2.

RESULTS

At week 2, the CDAI decreased significantly from baseline after infusion of natalizumab (mean 45 points) but not placebo (mean 11 points). Seven (39%) natalizumab-treated patients achieved remission at week 2, compared with 1 (8%) treated with placebo. In contrast, 4 (33%) of the placebo-treated patients required rescue medication by week 2, compared with 2 (11%) natalizumab-treated patients. Significant increases in circulating B and T lymphocytes were detected only after natalizumab administration. The frequency of commonly reported adverse events did not differ significantly between groups.

CONCLUSIONS

A single 3-mg/kg natalizumab infusion was well tolerated by Crohn's disease patients, although the dose used may have been suboptimal. Elevated circulating lymphocyte levels after natalizumab suggest interrupted lymphocyte trafficking. Natalizumab therapy in active Crohn's disease merits further investigation.

Measles vaccination and inflammatory bowel disease: a national British Cohort Study

OBJECTIVE

Measles vaccination has been suggested as a risk for inflammatory bowel disease. Atypical age of measles infection has also been associated with Crohn's disease. This study was designed to examine the relationship of measles vaccination and age of measles vaccination with later inflammatory bowel disease.

METHODS

A prospective population-based national birth cohort was used, of those born in 1 wk in April 1970 in Great Britain. The data are from 7616 responding members of the 1970 British Cohort Study with complete vaccination data, who were traced at age 26 yr. A diagnosis of Crohn's disease, ulcerative colitis, and diabetes mellitus (a control disease) was obtained by survey at age 26 yr, and confirmed by physicians. Vaccination data were from survey at age 5 yr. Measles and mumps infection data were obtained from the survey at age 10 yr. Adjustment was made for sex, household crowding in childhood, and father's social class at birth.

RESULTS

No statistically significant association was found between measles vaccination status at 5 yr and Crohn's disease (adjusted odds ratio [OR] 0.67, 95% confidence interval [CI] 0.27-1.63), ulcerative colitis (adjusted OR 0.57, 95% CI 0.20-1.61), or diabetes (adjusted OR 0.75, 95% CI 0.33-1.74). There was a statistically significant trend (p = 0.040) with increasing age of measles vaccination for risk of Crohn' s disease, although this was based on very few cases vaccinated after age 2 yr.

CONCLUSIONS

In this cohort, monovalent measles vaccination status is not associated with inflammatory bowel disease by age 26 yr. Older age at measles vaccination needs to be examined in other studies to confirm whether it is a genuine risk for Crohn's disease.

The initial care of newborn infants and subsequent hay fever

BACKGROUND

Patterns of neonatal exposure to microorganisms have changed substantially over the last 100 years, and it has been suggested that this has influenced the risk of immune-mediated disease. Using a proxy measure, we tested the hypothesis that the initial handling of newborn infants, which is known to affect the pattern of exposure to microorganisms, may alter the risk of developing subsequent atopy, as indicated by hay fever.

METHODS

Analysis was performed on 5,519 members of the 1970 British Cohort Study, a nationally representative birth cohort. Cohort members with hay fever were identified at intervals up to the age of 26 years. Details of neonatal care and childhood circumstances were recorded prospectively. Those who had spent their first night away from their mother in the communal infant nursery were selected as likely to have experienced atypical exposure compared with infants who remained with their mother. Adjustment was made for potential confounding factors in infancy and childhood by multiple logistic regression analysis.

RESULTS

Unadjusted relative odds (with 95% CI) for developing hay fever among those spending the first night in the communal nursery, when compared with other infants who remained with the mother, were 1.48 (1.23-1.77), P<0.001. Comprehensive adjustment for the potential confounding factors, including feeding practices on the first day of life, markers of social and material circumstances, and region, did not substantially alter this relationship, with adjusted relative odds of 1.31 (1.08-1.59), P=0.005.

CONCLUSIONS

While our proxy measure is associated with an increased risk of hay fever, further research is required to confirm that this is due to the pattern of infectious exposure in very early life. The results are consistent with the hypothesis that the first challenges are particularly important in the development of the newborn infant's immune system.

A placebo-controlled study to assess the effects of 7-day dosing with 10, 20 and 40 mg rabeprazole on 24-h intragastric acidity and plasma gastrin in healthy male subjects

AIM

To compare the effects of rabeprazole 10, 20 and 40 mg o.d. on 24-h intragastric acidity and plasma gastrin concentration in a randomized, double-blind placebo-controlled trial.

METHODS

Twenty-four healthy male volunteers were studied on the 7th day of morning dosing with either placebo or rabeprazole 10, 20 or 40 mg in a crossover fashion. On day 7, hourly intragastric acidity was measured for 24 h from 08.00 hours by gastric aspiration. Plasma gastrin concentrations were also measured hourly from 08.00 to 24.00 hours, and 2-hourly thereafter.

RESULTS

Compared with placebo, rabeprazole 10, 20 and 40 mg produced significant dose-related decreases in intragastric acidity (median 24-h integrated acidity=697, 186, 129 and 82 mmol h/L, respectively). This was associated with significant elevation of plasma gastrin concentration (median 24-h integrated gastrin=141, 1184, 1484 and 1763 pmol.h/L, respectively). Rabeprazole 40 mg resulted in significantly decreased acidity compared with both 10 and 20 mg, and in longer times for which intragastric pH was maintained at > 3 (19. 2 h vs. 17.3 h and 17.5 h) and > 4 (17 h vs. 14.2 h and 15.2 h), but was accompanied by significantly increased plasma gastrin. There was a consistent trend for greater antisecretory activity for 20 mg compared with 10 mg, but these differences did not reach statistical significance. The interindividual variability in antisecretory response was greatest with 10 mg.

CONCLUSIONS

Rabeprazole 10, 20 and 40 mg produce significant, profound dose-related inhibition of gastric acid secretion. Taking into account reciprocal increases in plasma gastrin and the interindividual variation in antisecretory response, 20 mg appears to be the preferred dose for routine clinical use.

Beta(beta)3-adrenergic receptors in human pancreatic islet and duodenal somatostatin neuroendocrine cells

BACKGROUND

We previously localized beta3-adrenergic receptors immunohistochemically in human gastrointestinal smooth muscle and incidently found a population of human pancreatic islet cells and duodenal epithelial neuroendocrine cells that also expressed beta3-adrenergic receptors.

AIM

To identify the nature of the islet and duodenal cells that stained positive for beta3-adrenergic receptors.

METHODS

Paraffin sections of human pancreas and duodenum and Chinese hamster ovary cells transfected with the human beta3-adrenergic receptor were immuno-stained for beta3-adrenergic receptors using an affinity-purified rabbit polyclonal antibody (anti-P12) raised against a 15 amino acid sequence (P12) of the human receptor. Immunohistochemical staining for the receptor was carried out in the presence and absence of P12 peptide and both somatostatin 14 and 18 peptides. beta3-adrenergic receptor-stained sections were also double-immunostained with anti-insulin, -glucagon, -somatostatin and -pancreatic polypeptide antibodies.

RESULTS

A subpopulation of human pancreatic islet cells and duodenal epithelial cells expressed positive cytoplasmic beta3-adrenergic receptor immunostaining. Using distribution and double-staining techniques, these cells were found to be somatostatin-positive D cells but not A or B cells. The positive staining of D cells with anti-P12 antibody was inhibited by prior incubation of the antibody with P12 peptide but not somatostatin-14 or -28 peptides. Pancreatic vascular smooth muscle and duodenal vascular and non-vascular smooth muscle also stained with anti-P12 antibody. Transfected Chinese hamster ovary cells showed positive membrane staining.

CONCLUSION

We have identified a population of neuroendocrine cells in the human pancreas and duodenum that express beta3-adrenergic receptors. These cells appear to be somatostatin D cells.

Endothelial changes precede mucosal ulceration induced by indomethacin: an experimental study in the rat

BACKGROUND

Indomethacin has been shown to damage the villous microvasculature concomitant with alterations in villous blood flow in the rat.

AIM

To test the hypothesis that alterations in blood flow result from ultrastructural damage to microvasculature endothelium.

METHODS

In anaesthetized rats, jejunal villi were exteriorized in a chamber and blood flow in surface capillaries visualized by fluorescence microscopy. Villi were exposed both luminally and systemically to indomethacin (100 microg/mL) for 10 min or until blood slowing or stasis had occurred in superficial capillaries (n=3 per group). Control animals received both a luminal and intravenous vehicle for 45 min (n=3). The small intestines were vascular perfusion-fixed with 1.5% glutaraldehyde and studied by transmission electron microscopy.

RESULTS

All controls appeared to be ultrastructurally normal. A 10 min exposure to indomethacin had no effect upon the epithelium but resulted in mild endothelial vacuolization and the development of small finger-like projections into the lumen of villus surface microvasculature. At the point of blood slowing, villus tip epithelium was again normal but the endothelial vacuolization and finger-like projections became more obvious. The endothelial projections and vacuolization became severe at the point of blood stasis; this also coincided with epithelial degeneration.

CONCLUSION

This study shows that villus surface microvasculature is the earliest site of morphological damage after indomethacin exposure.

Similarities between ileal Crohn's disease and indomethacin experimental jejunal ulcers in the rat

BACKGROUND

Both Crohn's disease ileal ulcers and indomethacin-induced jejunal ulcers in the rat have a predilection for the mesenteric margin of the bowel wall. Unlike the anti-mesenteric margin, the mesenteric margin is supplied by small end-arteries that might render it more sensitive to ischaemic injury.

AIM

To examine, in both situations, the histological relationship between the precise localization of small bowel ulcers and the mesenteric margin.

METHODS

Ileal Crohn's disease ulcers identified in surgical resection specimens (n=5) and indomethacin-induced lesions in the rat jejunum (n=6) were examined macroscopically and histologically.

RESULTS

In both the human ileum and the rat jejunum, ulcers occurred consistently along the mesenteric margin, with the most extensive mucosal injury occurring at two adjacent sites on either side of the midline of this margin. At these two sites, feeding arteries entered the muscularis propria.

CONCLUSIONS

For anatomical reasons apparently related to the vasculature of the human and rodent small bowel, specific sites along the mesenteric margin are susceptible to Crohn's disease ulceration and NSAID damage, respectively.

Early determinants of inflammatory bowel disease: use of two national longitudinal birth cohorts

OBJECTIVE

To examine previously cited early risk factors for inflammatory bowel disease.

DESIGN

The 1946 National Survey of Health & Development (NSHD) and the 1958 National Child Development Study (NCDS) are on-going, longitudinal birth cohort studies. A nested case-control design was used combining data from both cohorts; eight controls per case, matched for gender and social class, were selected randomly.

METHODS

Data concerning maternal infection in pregnancy (NCDS only), childhood infection (measles, mumps and whooping cough), birth order, appendicectomy, breast-feeding and measures of poor housing conditions in childhood were analysed. In both cohorts, the member's hospital physician or medical records were used to confirm the diagnosis.

RESULTS

Twenty-six cases of Crohn's disease and 29 cases of ulcerative colitis were identified. No significant association was found between the development of Crohn's disease or ulcerative colitis and any of the studied factors. There was a trend that those with Crohn's disease were more likely not to have been breast-fed (OR 0.4, 95% CI 0.15-1.03) and not to have had an appendicectomy (OR < 1.00). The opposite was true of those with ulcerative colitis (OR 2.76, 95% CI 0.86-9.81 and OR 2.34, 95% CI 0.69-7.46, respectively). The prevalence of inflammatory bowel disease was 5.12/1000 by the age of 43 years in NSHD and 2.02-2.54/1000 by the age of 33 years in NCDS.

CONCLUSIONS

The prevalence of inflammatory bowel disease in these cohorts is among the highest recorded in Europe. Childhood factors may be different for those with Crohn's disease and ulcerative colitis. These cohorts will be increasingly valuable data sources.

Conservation of the cag pathogenicity island of Helicobacter pylori: associations with vacuolating cytotoxin allele and IS605 diversity

BACKGROUND & AIMS

Specific regions of the cag pathogenicity island (PAI) believed to enhance the virulence of Helicobacter pylori, as well as vacuolating cytotoxin gene alleles and IS605 inserts, were investigated to define diversity within infecting strain populations from patients with peptic ulcer disease and from healthy individuals.

METHODS

The H. pylori studied comprised 67 isolates from 26 subjects and 14 reference strains. Specific polymerase chain reaction assays were used to test for cagA and picB in the cagI region, the virD4 homologue in the cagII region, IS605 in the genome and in the cag PAI, the "empty site" indicating absence of the cag PAI, and different vacA gene alleles.

RESULTS

Most (89%) subjects were infected by H. pylori with a contiguous cag PAI. No intermediate forms were found. IS605 was not detected within the cag PAI of any strain but was present elsewhere in the genomes of strains from 62% of subjects. Twenty individuals were infected with genotypically conserved populations of H. pylori. Six subjects had mixed infections, and in 3 of these cag(+)/cag(-) variants were present.

CONCLUSIONS

The cag PAI-positive H. pylori was a feature of most infected individuals, irrespective of severity of associated disease. Combined genotyping showed that 8 individuals (31%) had mixed infections, which suggests that strain population structure may be an additional contributing factor in disease development.

Helicobacter pylori: from the benign to the malignant

Half of the world's population is infected with Helicobacter pylori, making it a pathogen of potentially great significance. Although in the majority of cases, infection is harmless, many infected individuals develop peptic ulcer disease or gastric cancer. In developed countries, the prevalence of infection has decreased along with the incidences of duodenal and gastric ulcer and distal gastric cancer. In developing countries, H. pylori infection rates remain high, and, as life expectancy increases, the incidence of gastric cancer will increase. Recently, a working party of the World Health Organization designated H. pylori a class I carcinogen. This designation, along with the description of an H. pylori-infected animal model of gastric cancer, has strengthened the case for H. pylori eradication to prevent gastric cancer. However, concerns are growing that H. pylori eradication itself may cause harm. And, in developed countries, an increase in the rate of cancers arising near the gastroesophageal junction might be linked to the disappearance of H. pylori. Therefore, we are faced with a dilemma: Should we eradicate H. pylori to prevent cancer of the distal stomach, or should we leave it and hence avoid cancer of the proximal stomach or distal esophagus? The need for more reliable treatments further complicates the issue. So far, we cannot assume that current treatment regimens provide adequate eradication rates to justify widespread screening. Further research is needed to determine in whom, when, and how to eradicate H. pylori infection.

Demonstration of new sites of expression of the CCK-B/gastrin receptor in pancreatic acinar AR42J cells using immunoelectron microscopy

The CCK-B/gastrin receptor has been characterised in both normal and tumour tissues. Endocytosis of the CCK-B/gastrin receptor has recently been demonstrated and this has similarly been described for other peptide receptors. In addition, ligand and ligand-receptor translocation to the nucleus has been demonstrated for other peptides. The aim of this study was to identify the sites of expression of the CCK-B/gastrin receptor in the known CCK-B/gastrin receptor bearing pancreatic acinar AR42J cells. The specificity of the CCK-B/gastrin receptor antibody (alpha-CCKBR-Ser antibody) was demonstrated by inhibition ELISA studies, radioligand inhibition studies and immunofluorescence binding studies on AR42J cells. Western blotting and immunogold electron microscopy techniques were used to identify the receptor in AR42J cell preparations. The affinity purified alpha-CCKBR-Ser antibody was shown to be specific for the CCK-B/gastrin receptor. The receptor was expressed on the cell membrane, in the cytoplasm and within the nucleus. Isoforms of the receptor protein identified in extra-nuclear and nuclear extracts ranged in molecular weight from 58 to 66 kDa. We conclude that the CCK-B/gastrin receptor is not only expressed on the cell membrane, but also in the cytoplasm and nucleus of AR42J pancreatic acinar cells.

The effect of omeprazole dosing on the isolation of Helicobacter pylori from gastric aspirates

BACKGROUND

Animal experiments suggest that omeprazole dosing increases shedding of Helicobacter into the gastric lumen, and hence into gastric juice.

AIM

To assess the effect of omeprazole dosing on the yield of H. pylori from gastric aspirates of infected volunteers.

METHODS

Six serial nasogastric aspirates, three before and three during dosing with omeprazole 40 mg b.d., were obtained for culture from 10 H. pylori infected volunteers and one uninfected volunteer. To reduce contamination, samples were diluted 1:10 with Maximum Recovery Diluent (MRD; pH 7.0) or HCl-KCl buffer (pH 2.2) prior to culture on Columbia and Dent's agar.

RESULTS

Undiluted gastric juice cultures were rapidly overgrown by upper respiratory tract flora. HCl-KCl dilution resulted in isolation of H. pylori from 77% of infected subject aspirates before, and 67% of aspirates during dosing with omeprazole. The yields were significantly lower with MRD dilution, 47% and 10%, respectively. Omeprazole dosing significantly decreased the yield after MRD dilution, but not after HCl-KCl dilution.

CONCLUSIONS

Decreasing intragastric acidity, by dosing with omeprazole, decreases the isolation of H. pylori from routinely processed gastric aspirates. In vitro acidification of gastric aspirates, by HCl-KCl dilution, increases the isolation of H. pylori both before and during omeprazole dosing.

Laser assisted ratio analyser 13C-urea breath testing, for the detection of H. pylori: A prospective diagnostic European multicentre study

BACKGROUND

Novel technology based on laser optogalvanic spectroscopy called the LARA (Laser Assisted Ratio Analyser) system was developed to measure 12C/13C ratios in breath samples using stable 13C isotopes, to detect Helicobacter pylori infection.

AIM

To determine the sensitivity and specificity of the 13C-LARA-urea breath test in the detection of H. pylori infection in a prospective European multicentre trial; FDA-and EMEA-approved.

METHODS

Consecutive dyspeptic patients underwent diagnostic gastroscopy with biopsies for culture and histopathology, to detect H. pylori infection (gold standard). Subsequently, the LARA-urea breath test was performed using either a system without a cold trap (part I) or a system with a cold trap (part II). In both instances baseline, 30-min and 60-min breath samples were collected. The optimum cut-off level for 12C/13C ratios was determined by Receiver Operator Characteristics analysis.

RESULTS

In part I, 544 out of 604 patients were evaluable (low CO2: 47; withdrawn: 13). 284 out of 544 patients (52%) were H. pylori-positive according to the gold standard. The sensitivity of the LARA-urea breath test was 95% and the specificity 94%. In part II, 257 out of 272 were evaluable (low CO2: 14; withdrawn: 1). Sensitivity and specificity were 93% and 96%, respectively.

CONCLUSION

The LARA-technology represents an accurate and non-invasive testing system for the detection of H. pylori infection. Its major advantages are the use of stable 13C isotope, the high throughput of samples and the easy means of collecting, storing and transporting the samples, thus making the system convenient to both patient and clinician.

Review article: the pharmacology of rabeprazole

Rabeprazole sodium is a new substituted benzimidazole proton pump inhibitor with several differences compared with existing proton pump inhibitors. In vitro and animal studies have demonstrated that rabeprazole is a more potent inhibitor of H+,K(+)-ATPase and acid secretion than omeprazole, and is a more rapid inhibitor of proton pumps than omeprazole, lansoprazole, or pantoprazole. This probably reflects rabeprazole's faster activation in the parietal cell canaliculus. In human studies, once-daily doses of 5-40 mg of rabeprazole inhibit gastric acid secretion in a dose-dependent fashion. A once-daily dose of 20 mg has consistently achieved profound decreases in 24-h intragastric acidity in single and repeat dosing studies, in healthy volunteers and patients with either peptic ulcer disease or gastro-oesophageal reflux disease. Significantly greater decreases in intragastric acidity are achieved on day 1 of dosing with rabeprazole 20 mg than with omeprazole 20 mg. As with other proton pump inhibitors, rabeprazole has in vitro antibacterial activity against Helicobacter pylori, with greater activity against this organism than either lansoprazole or omeprazole. In addition to inhibiting bacterial urease activity, rabeprazole binds to several molecules on H. pylori. Clinical trials are needed to assess the clinical importance of these findings, as well as to assess whether the potential advantages of rabeprazole result in clinical benefit for patients with acid-related diseases.

Asian ethnic origin and the risk of inflammatory bowel disease

OBJECTIVE

To assess whether inflammatory bowel disease (IBD) is more prevalent in young Asians than Europeans living in Great Britain.

DESIGN

Longitudinal birth cohort study of all those born 5-11 April 1970 in Great Britain--the 1970 British Cohort Study (BCS70).

METHODS

The relationship of a diagnosis of ulcerative colitis or Crohn's disease by age 26 years with ethnic origin was investigated among 8,432 cohort members with complete data using multiple logistic regression. We adjusted for potential confounding factors, household crowding and sex, as well as for a family history of IBD.

RESULTS

Young Asians born in Britain were significantly more likely than indigenous Europeans to have a diagnosis of IBD by age 26 years, with relative odds of 6.10 (95% CI 2.14-17.33). This group of cohort members had ethnic origins in India, Pakistan or Bangladesh (although none of those from Bangladesh had IBD). This relationship remained statistically significant after adjustment for the potential confounding factors and family history of IBD.

CONCLUSION

Young Asians who were born in Britain are at a significantly higher risk of developing IBD than the indigenous European population. This may reflect a greater genetic predisposition to IBD that is uncovered by exposure to environmental factors.

The colonic mesenteric margin is most susceptible to injury in an experimental model of colonic ulceration

BACKGROUND

Crohn's disease ileal ulcers and indomethacin-induced jejunal ulceration in the rat tend to occur in the mucosa nearest to the mesentery (mesenteric margin), an area of the bowel wall that has a critical blood supply. Mercuric chloride induces caecal and colonic ulceration in the Brown Norway rat.

AIM

To examine whether the mesenteric margin is more sensitive to injury by a substance known to be vasculotoxic in the caecum and colon.

METHODS

Brown Norway rats received a single subcutaneous dose of either mercuric chloride 1 mg/kg or saline. The gastrointestinal tract was examined macro- and microscopically for lesions 48 h later. The vascular anatomy of the normal rat colon and caecum was also examined using the carbon ink perfusion technique.

RESULTS

Mercuric chloride induced caecal and colonic ulceration preferentially along the mesenteric margin of the bowel wall. Histologically, the lesions showed mucosal necrosis and neutrophil infiltration. There was also extensive vascular degeneration/necrosis with microaneurysm formation and extensive submucosal haemorrhage. Cellular infiltration of the vasculature was not a feature. The caecal and colonic mesenteric margins in control rats were supplied by small end arteries.

CONCLUSIONS

The colonic and caecal mesenteric margins are susceptible to injury by mercuric chloride, a chemical known to induce haemorrhagic vasculopathy in the rat gastrointestinal tract. The large bowel mesenteric margin may be susceptible to injury by mercuric chloride because of the critical blood supply to that side of the bowel wall.

Crohn's disease: the case for measles virus

Crohn's disease has the epidemiological and pathological hallmarks of an infection with a long natural history. Its emergence in developed countries in the middle of the 20th Century represents an instant in the continuum of human evolution, indicating either a new infection or, as with poliomyelitis, a changing pattern of exposure to a common childhood pathogen. Both short- and long-term outcomes from viral infection are largely dependent upon age and dose of exposure. We and others have suggested that measles virus may be causally related to Crohn's disease, and that the associated risk is an atypical pattern of exposure. Early, intensive, and concurrent infections have been identified as risks for subacute sclerosing panencephalitis, a delayed sequelae to measles virus infection, possibly through a process of high zone immunological tolerance and persistent infection. The data for Crohn's disease suggest that persistent infection may follow early low dose exposure and low zone immunological tolerance. The changing pattern of measles virus exposure this century would be consistent with a shift towards lower dose of infection. Such an exposure would also be consistent with persistence of the virus at very low copy number within discrete foci of granulomatous inflammation. The ability of measles virus to profoundly disrupt mucosal immune responses may provide the human counterpart of the cytokine-gene knockout.

Paramyxovirus infections in childhood and subsequent inflammatory bowel disease

BACKGROUND & AIMS

Measles virus has been implicated in the etiology of both inflammatory bowel diseases (IBDs), Crohn's disease and ulcerative colitis. Subacute sclerosing panencephalitis (SSPE) is caused by atypical measles infection. This study investigated the patterns of infection that are risks for SSPE, early infection and a close temporal relationship between measles and another infection, as potential risks for IBD.

METHODS

The data are from 7019 members of a nationally representative 1970 British Cohort Study. The ages of five childhood infections were recorded before onset of IBD symptoms. Diagnoses of IBD and insulin-dependent diabetes mellitus (IDDM), as a control disease, were identified by age 26 years.

RESULTS

Mumps infection before age 2 years was a risk for ulcerative colitis (odds ratio, 25.12; 95% confidence interval, 6. 35-99.36). Measles and mumps infections in the same year of life were significantly associated with ulcerative colitis and Crohn's disease, with odds ratios of 7.47 (2.42-23.06) and 4.27 (1.24-14.46), but not with IDDM. These relationships are independent of each other as well as sex, social class at birth, household crowding in childhood, and family history of IBD.

CONCLUSIONS

Atypical paramyxovirus infections in childhood may be risk factors for later IBD.

Patients consulting with Crohn's disease in primary care in England and Wales

OBJECTIVE

To determine annual incidence and prevalence for patients consulting their GP because of Crohn's disease in England and Wales and compare demographic details with matched controls.

DESIGN

We used the fourth Morbidity Statistics in General Practice study (MSGP-4) which covered 468 042 person-years during a 12-month period in 1991-92.

METHODS

All GPs reporting a patient with Crohn's disease in MSGP-4 were sent a questionnaire to confirm the diagnosis and obtain supportive details (surgical, pathological, radiological and/or endoscopic). Data concerning ethnicity, social class, smoking status, living in an urban or rural environment and employment had been collected previously. Conditional logistic regression models were used to analyse the data for cases and matched controls.

RESULTS

Three hundred and fifteen patients were reported to have Crohn's disease. Replies were obtained to 251 (80%) questionnaires. The diagnosis of Crohn's disease was confirmed in 184 cases (89%) and refuted in 23 cases (11%) -- details were unavailable for 44 patients. The mean age of patients was 44 years, the female:male ratio was 1.46:1, and 108 (59%) patients had required surgery. Thirty-three of 178 (18.5%) patients were diagnosed within the study period. Hence, this study detected a prevalence for consulting Crohn's disease of 54.6-59.8/100,000 and an annual incidence of 10.1-11.1/100,000 in 1991-92. No significant differences were found between cases (n = 291) and controls (n = 1682) with regard to ethnicity, social class, smoking or living in an urban/rural environment. Patients with Crohn's disease had similar employment levels as controls, but were significantly more likely to be registered as permanently sick, odds ratio 4.01 (CI 2.21-7.29).

CONCLUSIONS

This national survey, including 1% of the population, suggests there are approximately 30,600 patients consulting their GP because of Crohn's disease in England and Wales, with 5700 new cases diagnosed per year.

Comparison of three RNA amplification methods as sources of DNA for sequencing

DNA products generated from a region of the measles virus genome by three RNA reverse transcription and amplification methods were cloned and sequenced, and the results were compared in order to evaluate the methods' relative fidelities. The methods were: (i) reverse transcription followed by a nested polymerase chain reaction (RT-nPCR), (ii) a combined RT-PCR using rTth polymerase and (iii) nucleic acid sequence-based amplification (NASBA). NASBA was followed by RT-PCR with rTth polymerase or RT using AMV reverse transcriptase to generate DNA products for cloning. Products from all three sets of reactions were cloned into a vector, pT7Blue, and 790 bp of cloned DNA were sequenced and analyzed for base changes to determine the error rates for each amplification method. Sequence analysis of cloned RT-nPCR products showed no errors, whereas cloned rTth mediated RT-PCR products possessed an error rate of 0.38% and cloned NASBA products 0.38%. Products generated by NASBA followed by RT-PCR with rTth polymerase possessed an error rate of 1.9%. The results indicated that cloned DNA products generated by RT-nPCRs possessed least errors and that for NASBA, RT of reaction products before cloning and sequencing was preferable to using RT-PCR.

A placebo-controlled trial to assess the effects of 8 days of dosing with rabeprazole versus omeprazole on 24-h intragastric acidity and plasma gastrin concentrations in young healthy male subjects

BACKGROUND

Rabeprazole (LY307640, E3810) is a new, potent, proton pump inhibitor. A single daily 20 mg dose significantly decreases 24-h intragastric acidity. There are no data currently available directly comparing the effect of rabeprazole on 24-h acidity with established proton pump inhibitors.

AIM

To compare the effects of rabeprazole 20 mg o.m. and omeprazole 20 mg o.m. on 24-h intragastric acidity and plasma gastrin concentration in a randomized, double-blind, placebo-controlled trial, in healthy H. pylori-negative subjects.

METHODS

Twenty-four healthy male volunteers, negative for H. pylori infection by serology and 13C-urea breath test, were studied on the 1st and 8th day of dosing with either placebo, rabeprazole 20 mg or omeprazole 20 mg, once each morning, in a crossover fashion. On days 1 and 8, hourly intragastric acidity was measured by gastric aspiration for 24 h from 08.00 hours. On day 8, plasma gastrin concentrations were also measured hourly from 08.00 to 24.00 hours, then every 2 h thereafter.

RESULTS

A single dose of both rabeprazole and omeprazole significantly decreased 24-h intragastric acidity compared with placebo. The 24-h acidity on day 1 was significantly decreased for rabeprazole compared with omeprazole (331 vs. 640 mmol.h/L, P < 0.001), resulting in a significantly higher median 24-h intragastric pH and longer times at which intragastric pH was > 3 and > 4. On day 8 of dosing, the decrease in 24-h intragastric acidity was greater with rabeprazole than with omeprazole, but the difference was not statistically significant (160 vs. 218 mmol.h/L, P = 0.1). However, 24-h plasma gastrin concentration (1687 vs. 1085 pmol.h/L. P < 0.01) and percentage time that intragastric pH was > 3 (69 vs. 59%, P = 0.008) and > 4 (60 vs. 51%, P = 0.03) were significantly greater.

CONCLUSIONS

Rabeprazole 20 mg once daily has a significantly faster onset of antisecretory activity than omeprazole 20 mg once daily. After 8 days the differences in intragastric pH > 3 and > 4 holding times persisted, but there was no significant difference in 24-h acidity.

Reversal and protection against indomethacin-induced blood stasis and mucosal damage in the rat jejunum by a beta3-adrenoceptor agonist

BACKGROUND

In the rat, indomethacin causes jejunal villous shortening, microvascular distortion, and blood stasis prior to ulceration. The beta3-adrenoceptor agonist CL316,243 (CL) prevents both the early histological changes and ulceration.

AIM

To test the hypothesis that the beta3-adrenoceptor agonist CL316,243 exerts its protective effect by prevention and/or reversal of blood flow changes in the rat jejunum exposed to indomethacin.

METHODS

In anaesthetized rats, jejunal villous blood flow was measured in surface capillaries using fluorescence microscopy. Stasis of superficial capillary blood flow was induced by combined topical and i.v. indomethacin (100 microg/mL, 2.8 x 10(-4) M). To examine the effect of CL on blood stasis, CL was applied either i.v. (1 mg/kg) or luminally (100 microg/mL, 2.5 x 10(-5)M) at the onset of stasis. Prophylactic protection was assessed by giving i.v. CL simultaneously with indomethacin. Results were compared with controls which received luminal saline applied at blood stasis. The effect of i.v. CL (1 mg/kg) alone, or luminal CL (100 microg/mL) alone on basal villous blood flow was also examined. The small intestines were perfusion-fixed with 10% formol saline, and removed for histology, n = 5 for all groups.

RESULTS

Luminal CL given at stasis reversed indomethacin-induced stasis within 10 min, whereas i.v. CL did not. Pretreatment with i.v. CL prevented the onset of stasis. Basal blood flow was raised slightly only by luminal CL.

CONCLUSION

The beta-adrenoceptor agonist CL316,243 can protect against indomethacin-induced blood stasis in rat jejunal villi.

Absence of Escherichia coli, Listeria monocytogenes, and Klebsiella pneumoniae antigens within inflammatory bowel disease tissues

BACKGROUND

Escherichia coli, listeria, and streptococcal antigens have been found in Crohn's disease tissues. Antibodies to Klebsiella pneumoniae have been found in patients with inflammatory bowel disease and ankylosing spondylitis. The presence of these bacterial antigens in Crohn's granulomas would be of aetiological interest, while their presence in ulcers alone would be more likely to indicate secondary infection.

AIM

To investigate inflammatory bowel disease tissues for the presence of these bacteria.

METHODS

Formalin fixed, paraffin processed sections from 53 patients (19 ulcerative colitis, 23 Crohn's disease; 11 normal tissues from cancer resections) were studied by immunohistochemistry. Control tissue consisted of normal human small bowel injected submucosally with either E coli, Listeria monocytogenes, Proteus mirabilis, or Klebsiella pneumoniae serotypes K2, 3, 17, 21, 26, 36, and 50, and colonic biopsies from a child with E coli 0114 infection. Tissues were stained by Gram-Twort, and with specific antibodies for E coli (Dako B357), L monocytogenes (Difco 2302-50), and K pneumoniae (Biogenesis 5580-5208) using an immunoperoxidase technique.

RESULTS

Positive staining for E coli was observed on the luminal surface epithelium and in ulcers in 35% of Crohn's disease patients, 26% of ulcerative colitis patients, and no normal controls. Superficial staining for L monocytogenes was observed in one case of ulcerative colitis only. Staining for K pneumoniae was observed in one case of ulcerative colitis and one of Crohn's disease. No granulomas, giant cells, or germinal centres stained positively for any of the three bacterial antigens.

CONCLUSIONS

These data do not support a primary role for E coli, L monocytogenes, and K pneumoniae in inflammatory bowel disease. The presence of E coli antigens in ulcers suggests secondary infection in these lesions.

Measles IgM immunoreactivity in patients with inflammatory bowel disease

AIM

The purpose of our study was to examine measles IgM immunoreactivity in patients with inflammatory bowel disease.

PATIENTS AND METHODS

In an International collaborative study, serum measles IgM immunoreactivity was assayed in consecutive outpatients with Crohn's disease (n = 95), ulcerative colitis (n = 79), viral hepatitis (n = 63) and blood donors (n = 30). Two commercial measles assays--enzyme linked immunosorbent assay and indirect fluorescence assay--and a Public Health Laboratory Service (PHLS) "in house" antibody capture radioimmunoassay were used. Results were compared with serum rubella and Epstein-Barr virus-specific IgM immunoreactivity, total serum IgM, and measles IgG immunoreactivity. Twenty patients with inflammatory bowel disease were studied serially over a 4-month period.

RESULTS

By enzyme linked immunosorbent assay, the prevalence of raised serum measles IgM immunoreactivity was significantly greater in patients with Crohn's disease 23/95 (24%) and ulcerative colitis 20/79 (27%) compared with hepatitis patients 2/63 (3%) and normal controls 0/30 (0%) (p < 0.001). Indirect fluorescence assay produced significantly more positive results than enzyme linked immunosorbent assay in both Crohn's disease (50/87; 57%) and ulcerative colitis (35/68; 51%) but not in controls (0%) (p < 0.001). In contrast, no sera were positive using MCRIA. In the enzyme linked immunosorbent assay, measles IgM immunoreactivity did not correlate with either total IgM, rubella or Epstein-Barr virus IgM immunoreactivities-which were not raised-measles IgM immunoreactivity, or disease activity. Patients not receiving steroids were more likely to have raised measles IgM immunoreactivity (p < 0.5). All sera tested for Rheumatoid factor were negative. Of 20 patients with inflammatory bowel disease studied by ELISA over a 4-month period, 50% showed raised measles IgM immunoreactivity at some stage.

CONCLUSION

The data suggest a specific and fluctuating immune response to measles virus in patients with Crohn's disease and ulcerative colitis, that may be modified by corticosteroid therapy.

Measles virus RNA is not detected in inflammatory bowel disease using hybrid capture and reverse transcription followed by the polymerase chain reaction

Recent epidemiological and immunohistochemical studies have indicated a possible link between measles virus and inflammatory bowel disease (IBD). The aim of this study was to use a sensitive and robust method for the detection of measles virus RNA in IBD and control clinical samples. Peripheral blood mononuclear cells and intestinal resection tissue from IBD and control patients were studied. Two methods were used to determine the presence of measles virus RNA: hybrid capture, using measles virus-specific oligonucleotides linked to paramagnetic solid-phase supports, was carried out on total cellular RNA to enrich for measles virus RNA sequences. Reverse transcription followed by the polymerase chain reaction (RT-PCR) using rTth DNA polymerase was employed for amplification of measles virus N-gene sequences amongst the enriched species. Total RNA was also used for RT-PCR of a housekeeping mRNA species to assess RNA quality. RT-PCR for another region of the measles genome (the haemagglutinin (H) gene) was also undertaken in order to confirm the results obtained using N-gene primers for analysis of these samples. None of the samples were positive for measles N- or H-gene RNA using RT-PCR. Positive control samples confirmed the sensitivity of the methods employed. These results show that either measles virus RNA was not present in the samples, or was present below the sensitivity limits known to have been achieved.

What are appropriate end-points for Helicobacter pylori eradication in the treatment of duodenal ulcer?

The end-point of Helicobacter pylori eradication trials in peptic ulcer disease should be the presence or absence of continuing H. pylori infection, and not ulcer healing or recurrence. This is not to suggest that ulcer healing or prevention of recurrence is not the desired clinical end-point. It is to allow large trials to be conducted in a 'patient-friendly' manner and in a shorter time-scale, both of which reduce patient withdrawals, protocol violations and cost. For the same reasons, diagnosis of cure should be made by noninvasive means whenever possible. It is currently impossible to make anything other than generalisations regarding the relative efficacies of modern eradication regiments. As it seems unlikely that definitive head-to-head studies will be performed, the conduct and reporting of current trials needs to be improved and standardised, to allow meaningful comparisons. In particular, the course of each and every patient through the trial should be fully and clearly reported, especially withdrawals and dropouts. The primary efficacy analysis should be the intention-to-treat analysis, with per protocol and modified intention-to-treat analyses also reported, where appropriate.

A simple clinical colitis activity index

BACKGROUND

The appropriate medical treatment of patients with ulcerative colitis is determined largely by the severity of symptoms. Hospital assessment of the severity of disease activity includes investigation of laboratory indices and sigmoidoscopic assessment of mucosal inflammation.

AIMS

To develop a simplified clinical colitis activity index to aid in the initial evaluation of exacerbations of colitis.

METHODS

The information for development of the simple index was initially evaluated in 63 assessments of disease activity in patients with ulcerative colitis where disease activity was evaluated using the Powell-Tuck Index (which includes symptoms, physical signs, and sigmoidoscopic appearance). The new index was then further evaluated in 113 assessments in a different group of patients, by comparison with a complex index utilising clinical and laboratory data, as well as five haematological and biochemical markers of disease severity.

RESULTS

The newly devised Simple Clinical Colitis Activity Index, consisting of scores for five clinical criteria, showed a highly significant correlation with the Powell-Tuck Index (r = 0.959, p < 0.0001) as well as the complex index (r = 0.924, p < 0.0001) and all laboratory markers (p = 0.0003 to p < 0.0001).

CONCLUSIONS

This new Simple Colitis Activity Index shows good correlation with existing more complex scoring systems and therefore could be useful in the initial assessment of patients with ulcerative colitis.

Localization of the beta(beta)3-adrenoceptor in the human gastrointestinal tract: an immunohistochemical study

BACKGROUND

Activation of human and non-human colonic beta(beta)3-adrenoceptors causes smooth muscle relaxation. beta3-Adrenoceptor agonists protect against experimental indomethacin-induced jejunal ulceration. The mechanism of protection may involve spasmolytic/vasodilatory agonist activity. The precise localization of beta3-adrenoceptors in the human gut is not known.

AIM

To localize the beta3-adrenoceptor within the human gastrointestinal tract using the immunohistochemical technique.

METHODS

Human beta3-adrenoceptors were immuno-localized in paraffin sections of human oesophagus (OS), stomach (ST), duodenum (DU), ileum (IL), sigmoid colon (SC), rectum (R) and gall-bladder (GB) using the rabbit polyclonal antibody anti-P12. Staining was graded , ++, + and 0. Immunostaining of SC was also done with pre-incubation of anti-P12 with P12 peptide. Western blotting of anti-P12 on human and murine IL and SC isolated membrane proteins was performed.

RESULTS

All epithelia, vascular endothelial cells and ganglia scored 0. Smooth muscle of the vasculature, muscularis propria, muscularis mucosae and mucosa was graded, respectively, as follows; OS ( , , ,-), ST (++, , ++, ++), DU (++, , , +), IL (++, ++, ++, +), SC ( , ++, ++, ++), R (++, ++, +, +), GB ( , , -, 0). Pre-incubation of anti-P12 with P12 peptide almost abolished SC smooth muscle positivity. Western blot analysis using anti-P12 on human, but not murine, IL and SC membrane proteins revealed a single 5 5 kDa band, a size consistent with the predicted size of a partially glycosylated form of the human beta3-adrenoceptor.

CONCLUSIONS

This immunohistochemical study has localized the beta3-adrenoceptor to vascular and nonvascular smooth muscle in the human gastrointestinal tract. These findings support a role for the beta3-adrenoceptor in the control of blood flow and motility in the human gastrointestinal tract.

Focal reduction of villous blood flow in early indomethacin enteropathy: a dynamic vascular study in the rat

BACKGROUND

Oral indomethacin causes villous shortening, microvascular damage, and distortion, which might induce mucosal ischaemia and necrosis.

AIMS

In order to determine the early events in indomethacin induced jejunal injury we examined the temporal relations between morphological damage and changes in villous blood flow following indomethacin.

METHODS

In anaesthetised rats, mid jejunal villi were exteriorised in a chamber and observed by fluorescence microscopy. Blood flow in surface capillaries was calculated from velocities and diameters. Indomethacin was applied by both luminal and intravenous routes for 90 minutes, after which the animal was perfusion fixed and the villi were processed for histological examination. Control animals received intravenous or luminal bicarbonate (1.25%).

RESULTS

Blood flow slowed in individual villi at 20 minutes, and progressed to complete stasis (in another group) by 45 minutes. Histological examination at 20 minutes revealed microvascular distortion, but no villous shortening; crypt depth:villous height ratios were 0.356 (0.02) in test and 0.386 (0.01) in surrounding villi (p > 0.05). At stasis, the villi under study showed epithelial clumping and were shortened: crypt depth:villous height ratios were 0.92 (0.2) in test and 0.42 (0.06) in surrounding villi (p < 0.02). Vehicle alone had no effect on either blood flow or histology.

CONCLUSIONS

Focal slowing of villous blood flow and microvascular distortion precede villus shortening and epithelial disruption, and indicate that damage to surface microvasculature is an early event in indomethacin induced mucosal injury in this model.

The effects of low doses of ranitidine on intragastric acidity in healthy men

BACKGROUND

H2-receptor antagonists are becoming widely available as over-the-counter medications for the treatment of heartburn and excess gastric acidity.

AIM

To determine the effects of single low doses of ranitidine on intragastric acidity.

METHODS

Intragastric pH was measured for 9 h after lunch in five studies involving 24 healthy male volunteers. Antacid was given to all subjects on day 1. They then received single oral doses of a study drug 45 min after lunch on four separate occasions: placebo and either ranitidine 25 mg, 75 mg or 125 mg were given double-blind according to a predetermined randomization schedule.

RESULTS

During both of the post-dosing time periods (0-5 h and 5-9 h) there were significant decreases in integrated intragastric acidity for each ranitidine dose compared with placebo (P < 0.0001). There was a significant linear relationship between dose and integrated intragastric acidity with a greater decrease in acidity with increasing ranitidine doses (P < 0.0001). Compared with placebo, time with pH > 3 was significantly greater for ranitidine 75 mg and 125 mg (P < 0.001), but not ranitidine 25 mg. Results with the antacid were similar to placebo.

CONCLUSIONS

Using low doses of ranitidine (25, 75 or 125 mg) there was a dose-related decrease in intragastric acidity for 9 h after dosing. A single dose of antacid did not decrease intragastric acidity significantly.

Ulceration of the ileum in Crohn's disease: correlation with vascular anatomy

BACKGROUND

Ileal ulcers in Crohn's disease tend to lie along the same side of the bowel wall as the mesenteric attachment; the mesenteric and antimesenteric borders are supplied by short and long arteries, respectively.

AIM

To examine the localisation of ileal Crohn's ulcers and to test the hypothesis that predilection of Crohn's ulcers for the ileal mesenteric margin is explained by the existence of end arteries that supply the mesenteric margin.

METHODS

The localisation of ulcers in the bowel wall was examined in eight resection specimens of Crohn's disease of the terminal ileum. The vascular anatomy of normal terminal ileum (n = 8) and proximal jejunum (n = 8) postmortem specimens was studied; isolated long and short vessels were ligated before perfusion in four of these specimens.

RESULTS

All eight specimens of Crohn's disease of the terminal ileum showed longitudinal ulceration along the mesenteric margin. In the postmortem study, the submucosal vascular plexus derived from ileal, but not jejunal short vessels, comprised end arteries with little or no communication with the submucosal plexus arising from long vessels. Prior ligation of ileal, but not jejunal, short vessels resulted in a filling defect of the submucosal plexus along the mesenteric margin in three of the four specimens. Ligation of ileal and jejunal long vessels did not affect carbon ink perfusion of the bowel wall.

CONCLUSIONS

In the human terminal ileum, the short vessels supplying the mesenteric margin are end arteries, and their pathological occlusion might cause ischaemia of this region. These findings support a vascular hypothesis for Crohn's disease and may explain, in part, both the ileal and mesenteric distribution of Crohn's disease ulcers.