History of dyspepsia in Scotland. Admissions to the Edinburgh Royal Infirmary 1729-1830, doctoral theses 1726-1823, and contemporary British publications.

INTRODUCTION: The aim of the study was to assess whether the rise in the occurrence of dyspepsia in Scotland during the eighteenth century was a true epidemiologic phenomenon or just an increase in medical awareness. METHODS: Admissions for dyspepsia to the Edinburgh Royal Infirmary from 1729 until 1830 were analysed by consecutive five-year time periods. The titles of MD theses on dyspepsia from 1726 to 1823 were extracted from the Edinburgh University index. Monographs and articles on dyspepsia from Britain during the same time period were sought in the Catalogues of the US Surgeon-General's Library. RESULTS: During the eighteenth century, the annual number of dyspepsia patients admitted to the Edinburgh Royal Infirmary showed an extraordinary increase from none in 1730 to 900 per million population in 1760. About 4000 MD theses were presented to the Edinburgh University between 1726 and 1823. There were none on dyspepsia or gastritis between 1726 and 1749, after when it gradually started to rise. British publications on dyspepsia similarly appeared only in the 1790s and then rapidly increased. DISCUSSION: We suggest that the rise in MD theses and publications on dyspepsia were responses to a real increase in dyspepsia during the mid eighteenth century.

Three centuries of stomach symptoms in Scotland.

BACKGROUND: Stomach pain and discomfort have been reported since antiquity. AIM: To follow the time trends since the 18th century of dyspepsia, gastric ulcer, duodenal ulcer, and benign oesophageal disease to test when dyspepsia started to become a major clinical problem. METHODS: The annual in- and out-patient records of the last three centuries from the Scottish Royal Infirmaries of Edinburgh, Aberdeen, Glasgow and Dundee were analysed. In addition, dispensary attendances, clinicians' casebooks, students' notebooks and medical texts have been scrutinized for historic statistics of upper gastrointestinal disease. RESULTS: Dyspepsia was first recorded in the 1750s and increased markedly subsequently. Such dyspepsia persisted after gastric and duodenal ulcers appeared in the late 19th century and then declined again in the late 20th century. Non-ulcer dyspepsia has remained the commonest diagnosis made after endoscopy for stomach pain in the beginning of the 21st century. CONCLUSION: The current commonest diagnosis of stomach pain, dyspepsia dates from the mid-18th century. Any explanations of its causation need to consider this timing.

Inhibition of vascular smooth muscle cell adhesion and migration by c7E3 Fab (abciximab): a possible mechanism for influencing restenosis.

OBJECTIVES: Brief intravenous administration of chimeric antibody c7E3 Fab during coronary angioplasty has been shown in some studies to provide long term protection against coronary events. Smooth muscle cell (SMC) adhesion and migration are key initial steps in the development of restenosis. The purpose of this study was to investigate the effect of c7E3 Fab on adhesion and migration of SMC to the extracellular matrix (ECM) proteins osteopontin (Opn) and vitronectin (Vn). METHODS: Adhesion of human vascular SMCs to ECM proteins was quantified using a CyQUANT assay kit. Migration of SMCs to Vn, Opn and PDGF was studied using a modified Boyden's chamber migration assay. Integrin expression was determined by immunoprecipitation. RESULTS: c7E3 Fab reduced SMC adhesion on Vn and Opn to 69.2+/-3.3% (P<0.001) and 52.5+/-4.8% (P<0.001) respectively, compared to adhesion without antibody present. This reduction was the same as that for anti-alpha(v)beta(3) integrin antibody LM609 (P=0.5). The combination of anti-alpha(v)beta(5) integrin antibody and c7E3 Fab had a greater effect than either antibody alone (P<0.001). c7E3 Fab reduced SMC migration to Vn and Opn to 51.6+/-8.9% (P<0.001) and 20.3+/-6.1% (P<0.001) respectively, compared to migration in the absence of antibodies. Again, similar results were seen with LM609. PDGF-induced SMC migration was also inhibited by c7E3 Fab (P=0.004) and LM609 (P=0.001), but to much less an extent. The migration SMCs from a culture found not to express the alpha(v)beta(3) integrin was unaffected by these antibodies, strengthening the argument that c7E3 Fab inhibits SMC function via this integrin. CONCLUSIONS: c7E3 Fab inhibits the adhesion and migration of SMCs via the alpha(v)beta(3) integrin. The inhibition, however, is partial, and varied depending on type of ECM protein and alpha(v)beta(3) integrin expression. Some of the clinical benefits of c7E3 Fab may be due to its effect on SMCs.

In vitro evaluation of c7E3-Fab (ReoPro) eluting polymer-coated coronary stents.

OBJECTIVE: Stent thrombosis and in-stent restenosis remain problematic in certain patient sub-groups. c7E3-Fab (ReoPro, abciximab) inhibits the platelet glycoprotein IIb/IIIa receptor as well as the smooth muscle cell alpha(v)beta3 receptor, and thus may influence both processes, especially if high local concentrations could be achieved. We have studied the adsorption and elution characteristics of c7E3-Fab on commercially available polymer-coated stents. We have also investigated the effect of such antibody binding on platelet deposition in vitro, and on antibody deposition into ex vivo human saphenous vein wall to assess whether such stents may influence stent thrombosis and restenosis. METHODS AND RESULTS: Adsorption was measured using a radioisotope technique after immersing segments of polymer-coated stents in c7E3-Fab solutions. Uptake was dependent on antibody concentration and duration of immersion of wire in the solution. After 22 h (at 5 mg ml(-1)), 1146+/-101 ng cm(-1) wire was adsorbed. In an in vitro perfusion circuit, the antibody eluted slowly, with 53% remaining after 12 days washing. To determine the value that such stents might have in clinical practise, adsorption to balloon-mounted stents was assessed at room temperature, using commercially available c7E3-Fab (2 mg ml(-1)). Efficacy of eluting c7E3-Fab was determined by measuring deposition of 111-Indium platelets. Immersing stents in c7E3-Fab for 20 min inhibited platelet deposition by 82.3% compared to controls (P=0.018). Deployment of treated stents in ex vivo saphenous vein resulted in the deposition of c7E3-Fab in the intima and media. CONCLUSIONS: c7E3-Fab can be passively adsorbed onto polymer-coated stents. It elutes slowly and in a predictable manner, significantly inhibiting platelet deposition in vitro. These studies pave the way to developing stent-based delivery of a potent anti-platelet agent that may additionally affect smooth muscle cell activity.

Malabsorption and macroamylasemia. Response to gluten withdrawal.

A 36 year old woman presented with malabsorption and macroamylasemia. The macroamylase was characterized and shown to be a complex of pancreatic amylase and immunoglobulin A(IgA). The patient had the clinical and histologic features of adult celiac disease, and responded to a gluten-free diet. The macroamylase complex disappeared from the serum after gluten withdrawal, a hitherto unreported finding in the syndrome of malabsorption and hyperamylasemia.

Inhibition of platelet thrombosis using an activated protein C-loaded stent: in vitro and in vivo results.

In high-risk and complicated coronary intervention, the risk of acute closure is unpredictable. Thrombus and platelet deposition at the intervention site may also have further effects on subsequent restenosis. In vivo infusion of activated protein C has previously been shown to achieve potent anticoagulation without any haemostatic side effects. We now evaluated the in vitro and in vivo efficacy of polymer-coated coronary stents loaded with purified rabbit Activated Protein C (APC). By measuring 125I-fibrinogen/fibrin deposition APC-loaded stent-wires were antithrombotic compared to albumin-loaded, inhibited-APC-loaded, plain polymer-coated and stainless steel stent-wires. In a balloon injury rabbit iliac artery model, APC-loaded stents did not occlude (0/14) compared to plain stents (9/15) and BSA-loaded stents (2/4). Relative 111In-labelled platelet deposition showed a similarly significant degree of inhibition. In conclusion, APC-loading could render stents significantly less thrombotic. Whether an effective antithrombogenic stent like this effectively reduces restenosis rates warrants further evaluation.

Alimentary diseases in the poor and middle class in London 1773-1815, and in New York poor 1797-1818.

BACKGROUND: Although dyspepsia has been described for thousands of years, few studies have analysed its incidence before the 19th century when peptic ulcer first became a major dyspepsia-producing disease. METHODS: The incidence of alimentary disease around 1800 was examined in three private practices for the fee-paying middle class and in five public dispensaries for the poor in London, as well as in one dispensary in New York. RESULTS: The proportions of attendances for alimentary disorders were identical, 16%, in each of the three groups. Diarrhoea and dysentery were twice as common in the London dispensary than in private practice, presumably because of poor sanitation. Dyspepsia showed a similar incidence in the London dispensary and private practice, but was only half as common in New York. Worms were three times more common in dispensary patients in New York than in London. The incidence of diarrhoea and dyspepsia indicated no significant time trends over 43 years. None of the alimentary causes of death showed peptic ulcer at necropsy, and both haematemesis and intestinal haemorrhage were rare. CONCLUSIONS: Around 1800, the infrequent deaths from alimentary conditions suggested that the ulcer epidemic had not yet started. Instead, it is probable that the dyspepsia was similar to the non-ulcer dyspepsia of today.

Some effects of tripotassium dicitrato bismuthate on gastric secretion and the mucus barrier.

The effect of tripotassium dicitrato bismuthate (De-Nol) on the breakdown of the gastric mucus barrier was investigated by measuring the output of mucus glycoprotein in pentagastrin-stimulated secretion from 13 patients before and after treatment for peptic ulcer, and by examining the accumulation of dialysable peptides and amino acids (DPAA) in stimulated secretion from ten of these patients. The accumulation of DPAA was significantly reduced after De-Nol (by 54%) and to a greater extent than was the output of mucus glycoprotein (by 27%). These observations are consistent with a decrease in the rate of breakdown of the mucus barrier as a result of De-Nol treatment. De-Nol significantly reduced pepsin output (by 32%) in the same group of patients. Comparison of the change in pepsin output with the change in accumulation of DPAA in stimulated juice indicated that De-Nol increases the resistance of the mucus barrier to acid-pepsin proteolysis and/or inhibits the secretion of amino acids and peptides from gastric mucosa.

Two-week eradication regimen for metronidazole-resistant Helicobacter pylori.

At present there is no generally accepted treatment regimen for eradicating metronidazole-resistant Helicobacter pylori. This study determines the eradication rate after treatment with 40 mg omeprazole o.m. and 500 mg amoxycillin q.d.s. for 14 days, with 120 mg tripotassium dicitrato bismuthate q.d.s. for the first week (Days 1-7) and 750 mg ciprofloxacin b.d. for the second week (Days 8-14). Thirty patients (16 male, mean age 45 years, range 16-80 years) with duodenal ulcers (n = 18) or non-ulcer dyspepsia (n = 2) and metronidazole-resistant H. pylori detected by histology, culture, in vitro sensitivity tests and a positive 13C-urea breath test entered the study. Follow-up was by 13C-urea breath test at the end of treatment and at 1, 3, 6, and 12 months. Eradication was defined as a negative 13C-urea breath test at least 1 month after finishing treatment. H. pylori was successfully eradicated in 21/30 (71%) patients (median follow-up 10.2 months, range 4-12 months). A pre-treatment ciprofloxacin-resistant strain was isolated in 1/9 patients in whom eradication failed. Of 30 patients 29 completed the 2-week regimen; one patient experienced dizziness after 3 days of treatment. The most common side-effect was increased stool frequency (n = 6). This 2-week treatment regimen for metronidazole-resistant H. pylori is well tolerated and achieves an eradication rate of 70%.

Eradication of Helicobacter pylori and prevention of recurrence of duodenal ulcer: a randomized, double-blind, multi-centre trial of omeprazole with or without clarithromycin.

BACKGROUND: Antimicrobial treatment for Helicobacter pylori eradication is currently recommended for all patients with duodenal ulcer disease, but consensus on the best treatment is lacking. METHODS: Patients with active duodenal ulcer and H. pylori were enrolled in a double-blind, randomized, placebo-controlled multi-centre study. Patients received omeprazole 40 mg daily for 28 days and either clarithromycin 500 mg t.d.s. or placebo t.d.s. for the first 14 days. Patients underwent endoscopy before starting treatment, at 2 weeks, immediately after stopping treatment if unhealed at 2 weeks, and at 1, 6 and 12 months after the end of treatment, or at the recurrence of symptoms. Eradication of H. pylori, duodenal ulcer healing and ulcer recurrence were measured. RESULTS: One-hundred and fifty-four patients were recruited and randomized to omeprazole plus clarithromycin (n = 74) or to omeprazole plus placebo (n = 80). One month after treatment, H. pylori was eradicated in 57 of 69 (83%; 95% CI: 72-91%) patients receiving omeprazole plus clarithromycin, compared with 1 of 75 (1%; 95% CI: 0-7%) receiving omeprazole alone (P < 0.001). In patients receiving omeprazole plus clarithromycin the ulcer healed at 2 weeks in 83% (95% CI: 71-91%) and at 4 weeks in 100% (95% CI: 95-100%), compared with 77% (95% CI: 66-86%) and 97% (95% CI: 91-100%) in those given omeprazole plus placebo (N.S.). Ulcers recurred at 12 months in 6% (95% CI: 1-16%) of patients given omeprazole plus clarithromycin, compared with 76% (95% CI: 63-86%) of patients given omeprazole plus placebo (P < 0.001). The incidence of side-effects was similar in both treatment groups (38% with clarithromycin dual therapy and 29% with omeprazole plus placebo; P = 0.304). Ninety per cent of patients took at least 90% of their prescribed medication. CONCLUSIONS: Omeprazole plus clarithromycin dual therapy eradicated H. pylori in 83% of patients with duodenal ulcer and significantly decreased 12-month recurrence from 76% to 6%.

Eradication of Helicobacter pylori with lansoprazole and clarithromycin.

BACKGROUND: Helicobacter pylori eradication with omeprazole and clarithromycin varies between 40 and 80%. The dose, frequency and duration of treatment may account for these differences. Lansoprazole, a recently introduced proton pump inhibitor, is a more potent H. pylori bacteriostat in vitro than omeprazole. The aim of this open, comparative, randomized study was to investigate the efficacy and safety of lansoprazole 30 mg once or twice a day (and for 2 vs. 4 weeks) plus clarithromycin 500 mg t.d.s. for 2 weeks. in the eradication of H. pylori. METHODS: Sixty-six patients with H. pylori infection received clarithromycin 500 mg t.d.s. for 2 weeks and one of four lansoprazole regimens: 30 mg once a day for 2 (Group 1, n = 16) or 4 (Group 2, n = 16) weeks, or 30 mg b.d. for 2 (Group 3, n = 18) or 4 (Group 4, n = 16) weeks. H. pylori eradication was determined by the 13C-urea breath test 4 weeks after finishing treatment. RESULTS: Per protocol analysis (53 patients) shows that H. pylori was eradicated in 6/13 (46%) in Group 1, 7/13 (54%) in Group 2, 9/14 (64%) in Group 3 and 9/13 (69%) in Group 4. Thirty-one of 68 patients experienced side effects. Analysis on an intention-to-treat basis gave similar results. CONCLUSION: The dose of lansoprazole appears to be more important than the duration of therapy. Dual therapy with lansoprazole and clarithromycin should be investigated further as a possible treatment regimen for H. pylori infection.

Balsalazide in the maintenance treatment of patients with ulcerative colitis, a double-blind comparison with sulphasalazine.

Balsalazide (BSZ) is a pro-drug which releases 5-aminosalicylic acid (5ASA) and 4-aminobenzoyl-beta-alanine (an inert carrier) in the colon of various species including man. BSZ was compared with sulphasalazine (SASP) (both 1 g b.d. orally) in the maintenance of remission in patients with ulcerative colitis (UC). Seventy-nine patients (53 male, 26 female), mean age 49 years (range 19-79 years), with UC were randomly allocated to either treatment (41 BSZ, 38 SASP) for 6 months. The groups were similar in respect of age, sex, duration and extent of disease. Seven patients defaulted (3 BSZ, 4 SASP) leaving 38 on BSZ and 34 on SASP. Two male patients, both receiving SASP, were withdrawn because of severe side-effects. One of these patients, with an exfoliative rash, was maintained satisfactorily on open BSZ. Remission rates at 6 months (51% BSZ, 63% SASP) were not significantly different (life-table analysis P less than 0.1). Twelve patients (15%) reported troublesome side-effects (2 BSZ 5%, 10 SASP 26%, P = 0.017 Fisher Exact Test). Mean haemoglobin concentrations, similar on entry, increased after 6 months with BSZ (0.2 g/dl) but decreased with SASP (0.5 g/dl) (P less than 0.0002). BSZ was not significantly different from SASP in maintaining remission in patients with UC but had fewer side-effects.

Lansoprazole, clarithromycin and metronidazole for seven days in Helicobacter pylori infection.

BACKGROUND: This study determines the efficacy and safety of a 1-week triple therapy regimen of lansoprazole, clarithromycin and metronidazole in an area with a high prevalence of pre-treatment metronidazole-resistant strains of Helicobacter pylori. METHODS: Seventy-five H. pylori positive patients with gastritis or duodenal ulcer were entered into an open study of lansoprazole 30 mg o.m., clarithromycin 250 mg b.d. and metronidazole 400 mg b.d. H. pylori status was determined by CLOtest, histology, culture and by 13C-urea breath test (repeated > or = 28 days after treatment). RESULTS: Seventy-one patients completed the treatment and returned for follow-up. H. pylori was eradicated in 61 of 71 (86%) patients by per-protocol analysis, and in 61 of 75 (81%) patients by intention-to-treat analysis. H. pylori was eradicated in 12 of 16 (75%) patients with metronidazole-resistant strains compared with 22 of 24 (92%) in patients with metronidazole-sensitive strains of H. pylori (P = 0.14). Fourty-five patients reported at least one adverse event, and three patients stopped treatment due to them (two with headaches and one with diarrhoea). CONCLUSIONS: A 1-week course of lansoprazole 30 mg o.m., clarithromycin 250 mg b.d. and metronidazole 400 mg b.d. eradicates H. pylori in up to 86% of patients. It is of proven benefit in patients with pre-treatment metronidazole-resistant strains of H. pylori.

Recurrence of duodenal ulcer after Helicobacter pylori eradication is related to high acid output.

BACKGROUND: Helicobacter pylori eradication reduces the recurrence of duodenal ulcers. It is unclear why duodenal ulcers rarely recur in the absence of reinfection with H. pylori or NSAID treatment. METHODS: Basal, gastrin-releasing peptide- and pentagastrin-stimulated peak acid outputs in patients with ulcer relapse after H. pylori eradication were measured, and compared with patients without ulcer relapse after H. pylori eradication. RESULTS: Pentagastrin-stimulated peak acid output was significantly higher in H. pylori-positive patients with duodenal ulcers than in H. pylori-negative controls, and fell significantly after H. pylori eradication. In H. pylori-negative patients with recurrent duodenal ulcers, pentagastrin-stimulated peak acid output was significantly higher than in controls and similar to H. pylori-positive patients with duodenal ulcers. CONCLUSIONS: These findings suggest that duodenal ulcer relapse after eradication of H. pylori may be related to high pentagastrin-stimulated peak acid output. In this subset of patients with duodenal ulcers, maintenance anti-secretory treatment may be necessary to prevent relapse.

Improved maintenance of remission in ulcerative colitis by balsalazide 4 g/day compared with 2 g/day.

The efficacy of two doses of balsalazide for the maintenance of remission in patients with ulcerative colitis was compared in a double-blind multicentre trial. Sixty-five patients received a 2 g daily dose, and 68 a 4 g dose. The patient groups were similar at entry for sex, age, and disease distribution. Clinical assessment was carried out at 3-monthly intervals, with sigmoidoscopy, rectal biopsy, and blood tests on entry and at 26 and 52 weeks. Clinical relapse over twelve months was significantly less common on the 4 g dose (36%), than on the 2 g dose (55%), P less than 0.01. There were eight withdrawals on 2 g daily and 13 on 4 g daily, six and nine respectively being mainly due to gastrointestinal intolerance. It is concluded that balsalazide is a well-tolerated drug, and is effective for the maintenance of remission in patients with ulcerative colitis, the optimal dose being greater than 2 g daily.

Breakdown of gastric mucus in presence of Helicobacter pylori.

The potential of Helicobacter pylori to degrade gastric mucus was examined. Colonies of H pylori cultured from antral mucosal biopsy specimens of patients with non-autoimmune gastritis were washed with sterile saline, passed through a sterilisation filter, and the filtrate examined for urease, protease, and mucolytic activity. The filtrate failed to hydrolyse bovine serum albumin, or to degrade stable mucus glycoprotein structures of high particle weight that had been separated from human gastric mucus on Sepharose 2B. The high particle weight mucus glycoprotein was, however, extensively degraded when incubated with H pylori filtrate (which possessed urease activity) in the presence of 2 M urea, to release fragments of Mr approximately 2 X 10(6). The high particle weight mucus glycoprotein was also broken down to a comparable extent when incubated with Jack bean urease in the presence of 2 M urea, or 1 M ammonium carbonate, or 40 mM carbonate-bicarbonate buffer (pH 8.7), but not when treated with 4 M urea alone, or Jack bean urease alone. These results indicate that the loss of high particle weight mucus glycoprotein in gastric mucus from patients with gastritis and gastric ulcers is unlikely to be due to the mucolytic action of an extra-cellular protease produced by H pylori, but it may result from the destabilising effects of a carbonate-bicarbonate buffer, generated at the mucosal surface when H pylori urease hydrolyses transuded plasma urea.

Parietal cells in the duodenal bulb and their relation to Helicobacter pylori infection.

AIM: To investigate the prevalence, and relation to Helicobacter pylori, of parietal cells in the duodenal bulb using a monoclonal antibody directed against H+,K(+)-ATPase (HK12.18). METHODS: Twenty six patients with duodenal ulcer disease and 16 healthy controls were studied. H pylori status was determined by gastric histology and culture and by the 13C-urea breath test. Four biopsy specimens were taken from the duodenal bulb and stained with HK12.18. The presence/absence and number of parietal cells in the duodenal bulb were assessed blindly by a histopathologist. RESULTS: The overall prevalence of parietal cells in the duodenal bulb was 31% (13/42) and was similar in patients with duodenal ulcer and in controls, and in H pylori positive and negative subjects. The median (range) number of parietal cells in the duodenal bulb was 7.5 (4-20) parietal cells/subject, and was similar in all four groups. CONCLUSIONS: The prevalence of parietal cells in the duodenal bulb (31%) is notably higher than previously reported in endoscopic studies, and is in keeping with reports from studies on necropsy/operative specimens. There was no difference in the prevalence or number of parietal cells in the duodenal bulb between patients with duodenal ulcer and controls, regardless of H pylori status. These findings suggest that parietal cells in the duodenal bulb do not contribute to the pathogenesis of duodenal ulcer.

Campylobacter pylori in the upper gastrointestinal tract of patients with HIV-1 infection.

Fifty one patients with human immuno-deficiency virus (HIV-1) infection who had been consecutively endoscoped for upper gastrointestinal symptoms were biopsied (stomach or duodenum, or both) and compared with 59 age and sex matched controls for the presence of Campylobacter pylori. In 28 (47%) of the control group but in only seven (14%) of the HIV seropositive patients were C pylori seen on histological examination (p less than 0.001, odds ratio 5.6, 95% confidence interval 2.2-14.5). Sixteen patients who were HIV antibody positive had other index diseases for the diagnosis of AIDS in the biopsy material and, when these were excluded, comparison with the control group still showed a significant difference; p less than 0.01, odds ratio 3.6, 95%, confidence interval 1.4-9.6. In this series, therefore, C pylori were far less common in HIV antibody positive patients than in controls. Among the HIV positive patients, a higher proportion of C pylori negative cases had AIDS but this trend was not significant. The findings of this study indicate that whatever abnormalities of cell mediated mucosal immunoregulation are caused by HIV infection, they do not seem to be important in the response to infection by C pylori.

Routine cleaning and the elimination of Campylobacter pylori from endoscopic biopsy forceps.

The effect of routine cleaning in removing Campylobacter pylori from the biopsy forceps of endoscopes has been examined in a series of 50 patients. Campylobacter pylori was isolated from the biopsies of 15 of the patients, while one of the 50 biopsy forceps washings yielded the organism after routine cleaning. This study suggests that there is a small chance of transmitting C. pylori by endoscopic equipment if cleaning is the only method of decontamination adopted.

Motility of Helicobacter pylori in a viscous environment.

BACKGROUND: Patients with gastroduodenal disease produce gastric mucus of higher viscosity, and mucins that are of a smaller size, than normal. We have modelled these changes to the mucus layer in solutions of methylcellulose, and measured bacterial motility in biopsied mucus, to assess how they might influence the movements of Helicobacter pylori. METHODS: Motilities of Helicobacter pylori were measured in solutions of methylcellulose with molecular mass of 14 and 41 kDa, and in biopsied mucus with a Hobson BacTracker. Four parameters of bacterial motility were quantified: curvilinear velocity (CLV), path length, track linearity and curvature rate. RESULTS: All H. pylori were motile in methylcellulose solutions, and had optimal motilities at a viscosity of 3 cp (CLV in methylcellulose of 41 kDa, for instance, was 33 +/- 1.4 microm/s (mean +/- SEM) and the path length in methylcellulose of 41 kDa was 22.4 +/- 2 microm). At higher viscosities, mean CLVs, path lengths and curvature rates decreased, and track linearities increased in direct proportion to the increase in methylcellulose viscosity. Bacteria become non-motile at a viscosity of 50 cp in methylcellulose of 14 kDa, and at 70 cp in methylcellulose of 41 kDa. Mean CLVs, path lengths and curvature rates (but not track linearities) were greater in methylcellulose of 41 kDa than in methylcellulose of 14 kDa at each viscosity tested. Motilities of H. pylori from patients with duodenal ulcer or non-ulcer dyspepsia in methylcellulose solutions were not significantly different. H. pylori had poor motility in biopsied mucus, but became highly motile when biopsied mucus was diluted with saline. CONCLUSIONS: The viscosity-motility profiles of H. pylori in methylcellulose and the motilities of H. pylori in biopsied mucus suggest (1) that H. pylori may have poor motility in mucus at the epithelial surface, but high motility at the luminal surface of the mucus layer, and (2) that the increased mucus viscosity and decreased mucin size in patients with gastroduodenal disease act in combination to decrease H. pylori motility in vivo.