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Dive into the research topics where A. T. R. Axon is active.

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Featured researches published by A. T. R. Axon.


Alimentary Pharmacology & Therapeutics | 2002

Current concepts in the management of Helicobacter pylori infection--the Maastricht 2-2000 Consensus Report.

Peter Malfertheiner; Francis Mégraud; Colm O'Morain; A. P. S. Hungin; Roger Jones; A. T. R. Axon; David Y. Graham; Guido N. J. Tytgat

Significant progress and new insights have been gained in the 4u2003years since the first Maastricht Consensus Report, necessitating an update of the original guidelines. To achieve this, the European Helicobacter Pylori Study Group organized a meeting of specialists and experts from around the world, representatives from National Gastroenterology Societies and general practitioners from Europe to establish updated guidelines on the current management of Helicobacter pylori infection. The meeting took place on 21–22 September 2000.


Gut | 2017

Management of Helicobacter pylori infection—the Maastricht V/Florence Consensus Report

Peter Malfertheiner; Francis Mégraud; Colm O'Morain; Javier P. Gisbert; Ernst J. Kuipers; A. T. R. Axon; Franco Bazzoli; Antonio Gasbarrini; John Atherton; David Y. Graham; Richard H. Hunt; Paul Moayyedi; Theodore Rokkas; Massimo Rugge; Michael Selgrad; Sebastian Suerbaum; Kentaro Sugano; Emad M. El-Omar

Important progress has been made in the management of Helicobacter pylori infection and in this fifth edition of the Maastricht Consensus Report, key aspects related to the clinical role of H. pylori were re-evaluated in 2015. In the Maastricht V/Florence Consensus Conference, 43 experts from 24 countries examined new data related to H. pylori in five subdivided workshops: (1) Indications/Associations, (2) Diagnosis, (3) Treatment, (4) Prevention/Public Health, (5) H. pylori and the Gastric Microbiota. The results of the individual workshops were presented to a final consensus voting that included all participants. Recommendations are provided on the basis of the best available evidence and relevance to the management of H. pylori infection in the various clinical scenarios.


Gut | 1991

Acute Helicobacter pylori infection: clinical features, local and systemic immune response, gastric mucosal histology, and gastric juice ascorbic acid concentrations.

G. M. Sobala; J. E. Crabtree; M. F. Dixon; C. J. Schorah; J. D. Taylor; B. J. Rathbone; R V Heatley; A. T. R. Axon

The symptomatology of a case of acute infection with Helicobacter pylori is described, together with the accompanying changes in gastric mucosal histology, local and systemic humoral immune response, and gastric ascorbic acid concentration. The patient was an endoscopist, previously negative for the carbon-14 urea breath test, who had a week of epigastric pain and then became asymptomatic. H pylori was detected by culture of antral biopsy specimens and was still present after 74 days. Five days after infection the histological findings showed acute neutrophilic gastritis; by day 74 changes of chronic gastritis were evident. The patient seroconverted by IgG enzyme linked immunosorbent assay by day 74, but a mucosal IgM and IgA response was evident as early as day 14. Infection was accompanied by a transient hypochlorhydria but a sustained fall in gastric juice ascorbic acid concentration.


Gut | 1993

Failure of colonoscopic surveillance in ulcerative colitis.

D. A. F. Lynch; A J Lobo; G. M. Sobala; M. F. Dixon; A. T. R. Axon

A prospective surveillance programme for patients with longstanding (> = 8 years), extensive (> = splenic flexure) ulcerative colitis was undertaken between 1978 and 1990. It comprised annual colonoscopy with pancolonic biopsy. One hundred and sixty patients were entered into the programme and had 739 colonoscopies (4.6 colonoscopies per patient; 709 patient years follow up). Eight eight per cent of examinations reached the right colon. There was no procedure related death. One Dukess A cancer was detected. Forty one patients (25%) defaulted. Of these 25 remain well; 13 are unaccounted for, and one died from colonic cancer. One patient had colectomy for medical reasons, and another died of carcinoma of the pancreas. Retrospectively an additional 16 eligible patients were identified who had not been recruited. Of these, 14 remain well, two are unaccounted for. None developed colonic cancer. Four patients refused colonoscopy. All remain well. Over the same period seven other cases of colonic cancer were found in association with ulcerative colitis, two in patients who had erroneously been diagnosed as having only proctitis and were therefore not entered into the programme, but were found at operation to have total colitis, one in a patient with colitis of seven years duration, and four patients who had previously attended the clinic but had been lost to follow up before 1978 and then had represented with new symptoms during the surveillance period. Thus, of the nine colitis related cancers diagnosed in this centre during the study period only one was detected by the surveillance programme. The results of this large study, a a review of published works, cast doubts on the effectiveness of colonoscopic surveillance programmes in detecting colorectal cancer in patients with ulcerative colitis.


Gastroenterology | 1989

Ascorbic acid in the human stomach

G.M. Sobala; C.J. Schorah; M. Sanderson; M. F. Dixon; D.S. Tompkins; P. Godwin; A. T. R. Axon

Ascorbic acid, the reduced form of vitamin C, may protect against gastric cancer. Accordingly, this study assessed the variability of ascorbic acid and vitamin C in the gastric juice of 77 patients with dyspepsia. There was a vitamin C concentration gradient from gastric juice down to plasma in subjects with normal gastric mucosa, but not in those with chronic gastritis. Patients with chronic gastritis had significantly lower gastric concentrations of vitamin C and ascorbic acid, and ascorbic acid concentrations were especially low in subjects with hypochlorhydria. The presence of the concentration gradient suggests that a mechanism for the secretion of vitamin C into the stomach exists. This is compromised by chronic gastritis. The very low ascorbic acid concentrations in hypochlorhydria may be a consequence of oxidation by bacterial nitrite. Those patients who by the Correa model are at greatest risk for gastric cancer have the lowest gastric levels of ascorbic acid.


Gut | 1993

Effect of eradication of Helicobacter pylori on gastric juice ascorbic acid concentrations.

G. M. Sobala; C. J. Schorah; S. Shires; D. A. F. Lynch; B. Gallacher; M. F. Dixon; A. T. R. Axon

Ascorbic acid, the reduced form of vitamin C, may protect against gastric cancer and is secreted by the normal stomach. Secretion is impaired in Helicobacter pylori (H pylori) associated chronic gastritis. This study examined if eradication of H pylori improves gastric juice ascorbate values. Fasting gastric juice and plasma samples were collected at endoscopy from patients participating in trials of H pylori eradication for duodenal ulcer disease and intestinal metaplasia before and up to 15 months after attempted eradication. Ascorbic acid and total vitamin C concentrations were determined by high performance liquid chromatography. In 12 patients in whom H pylori was successfully eradicated gastric juice ascorbate and total vitamin C concentrations and the ratio of juice to plasma vitamin C rose after treatment. Analysis after treatment suggested that the rise was greatest in patients with high final plasma vitamin C concentrations, even though these did not change with treatment. By contrast, in 22 patients in whom H pylori eradication was unsuccessful there were no significant changes in juice or plasma concentrations after treatment. It is concluded that successful eradication of H pylori improves secretion of vitamin C into gastric juice. It is speculated that this increases protection against gastric cancer.


Alimentary Pharmacology & Therapeutics | 1996

Reflux symptom relief with omeprazole in patients without unequivocal oesophagitis

C. M. Bate; S. M. Griffin; P. W. N. Keeling; A. T. R. Axon; M. W. Dronfield; Roger W. Chapman; D. O'donoghue; John Calam; J. Crowe; R. A. Mountford; D. A. Watts; M. D. Taylor; P. D. I. Richardson

Background: As many as 50% of patients with reflux symptoms have no endoscopic evidence of oesophagitis. This multicentre study was designed to assess symptom relief after omeprazole 20 mg once daily in patients with symptoms typical of gastro‐oesophageal reflux disease but without endoscopic evidence of oesophagitis.


Gut | 1998

Reactive oxygen species activity and lipid peroxidation in Helicobacter pylori associated gastritis: relation to gastric mucosal ascorbic acid concentrations and effect of H pylori eradication

I. M. Drake; N P Mapstone; C. J. Schorah; K. L. M. White; D M Chalmers; M. F. Dixon; A. T. R. Axon

Background—Helicobacter pylori is an independent risk factor for gastric cancer, and this association may be due to the bacterium causing reactive oxygen species mediated damage to DNA in the gastric epithelium. High dietary ascorbic acid intake may protect against gastric cancer by scavenging reactive oxygen species. Aims—To assess reactive oxygen species activity and damage in gastric mucosa in relation to gastric pathology and mucosal ascorbic acid level, and to determine the effect of H pylori eradication on these parameters. Patients—Gastric biopsy specimens were obtained for analysis from 161 patients undergoing endoscopy for dyspepsia. Methods—Reactive oxygen species activity and damage was assessed by luminol enhanced chemiluminescence and malondialdehyde equivalent estimation respectively. Ascorbic acid concentrations were measured using HPLC. Results—Chemiluminescence and malondialdehyde levels in gastric mucosa were higher in patients with H pylori gastritis than in those with normal histology. Successful eradication of the bacterium led to decreases in both parameters four weeks after treatment was completed. Gastric mucosal ascorbic acid and total vitamin C concentrations were not related to mucosal histology, but correlated weakly with reactive oxygen species activity (chemiluminescence and malodialdehyde levels). Conclusions—Data suggest that reactive oxygen species play a pathological role in H pylori gastritis, but mucosal ascorbic acid is not depleted in this condition.


Helicobacter | 2010

Epidemiology of Helicobacter pylori infection and Public Health Implications

Alexander C. Ford; A. T. R. Axon

This article summarizes the published literature concerning the epidemiology and public health implications of Helicobacter pylori infection published from April 2009 through March 2010. Prevalence of infection varied between 7 and 87% and was lower in European studies. All retrieved studies examining transmission of infection concluded that spread is from person‐to‐person. One study collecting stool and vomitus samples from patients with acute gastroenteritis detected H. pylori DNA in 88% of vomitus and 74% of stool samples. Proposed risk factors for infection included male gender, increasing age, shorter height, tobacco use, lower socioeconomic status, obesity, and lower educational status of the parents in studies conducted among children. Decision analysis models suggest preventing acquisition of H. pylori, via vaccination in childhood, could be cost‐effective and may reduce incidence of gastric cancer by over 40%. As yet, no country has adopted public health measures to treat infected individuals or prevent infection in populations at risk.


Gut | 1996

Ascorbic acid and total vitamin C concentrations in plasma, gastric juice, and gastrointestinal mucosa : effects of gastritis and oral supplementation

A. J. Waring; I. M. Drake; C. J. Schorah; K. L. M. White; D. A. F. Lynch; A. T. R. Axon; M. F. Dixon

Epidemiological evidence suggests that high dietary ascorbic acid reduces gastric cancer risk. It may do this by either reducing N-nitroso compound formation in gastric juice, or by scavenging reactive oxygen species in gastric mucosa. The aim of this study was to discover if potential ascorbic acid protection might be increased by supplementation. Thirty two patients were supplemented with ascorbic acid, 500 mg twice daily for two weeks. Gastric juice, plasma, and upper gastrointestinal biopsy ascorbate concentrations were measured and compared with values in 48 unsupplemented patients. It was found that ascorbic acid and total vitamin C concentrations were considerably higher in biopsy specimens from oesophagus, body, antrum, duodenum, and rectum, compared with values in plasma or gastric juice. Plasma and mucosal concentrations were unaffected by the presence of chronic gastritis but gastric juice concentrations were substantially lower in patients with chronic gastritis than in patients with normal histological assessment (p < 0.01). Patients receiving ascorbic acid supplements had higher ascorbic acid concentrations in plasma (p < 0.001), gastric juice (p < 0.001), and at all biopsy sites in the upper gastrointestinal tract (p < 0.05). Gastric juice ascorbic acid and total vitamin C concentrations in gastritic patients, however, were still less after supplementation than in normal subjects (p < 0.01). These data suggest that high ascorbic acid intake could reduce gastric cancer risk, but its protective effect might be greater if gastritis is treated (for example, by Helicobacter pylori eradication).

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Jean E. Crabtree

St James's University Hospital

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Peter Malfertheiner

Otto-von-Guericke University Magdeburg

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David Forman

International Agency for Research on Cancer

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