title: Human gastric mucosal hydrophobicity does not decrease with Helicobacter pylori infection or chronological age.
abstract: OBJECTIVE
  Infection with cytotoxin-associated gene A (cagA) Helicobacter pylori is associated with severe gastric diseases. Previous studies in humans have reported a decreased gastric hydrophobicity with H pylori infection. The aim of the present study was to differentiate between the effect of cagA+ and cagA- strains on gastric mucus hydrophobicity.
  
  
  METHODS
  One hundred patients without peptic ulcers and not on medication were randomly recruited from endoscopy clinics; each patient had six biopsies. Contact angle measurements were performed using a goniometer assisted by computer software. H pylori status was assessed by histology, Campylobacter-like organism test and culture, and cagA+ status was determined by polymerase chain reaction.
  
  
  RESULTS
  In age- and sex-matched patients, there was no significant difference (P=0.27) in contact angle between H pylori-positive (61+/-2.8 degrees ) and H pylori-negative patients (65.5+/-3.0 degrees ). There was also no significant difference (P=0.36) in contact angle among H pylori-negative, cagA- and cagA+ patients (65.5+/-3.0 degrees , 58.6+/-3.6 degrees and 63.4+/-4.9 degrees , respectively). However, a trend of increased mean contact angles in cagA+ compared with cagA- and H pylori-negative patients was observed in patients 50 years and younger (68.3+/-8.3 degrees , 61.1+/-6.1 degrees and 63.6+/-2.2 degrees , respectively; P=0.70) and in patients without atrophy (71.1+/-8 degrees , 59.6+/-4 degrees and 66+/-2 degrees , respectively; P=0.30). In addition, there was no significant correlation between contact angles and patient age (r=0.104, P=0.306).
  
  
  CONCLUSIONS
  The present study shows that H pylori infection and the chronological age have no effect on the gastric mucus hydrophobicity, but it highlights a trend of increased mucus hydrophobicity with cagA+ infection that needs to be supported by future studies.
authors.affiliation: School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom. almarhoon@hotmail.com
authors.forename: Mohammed S
authors.initials: MS
authors.lastname: Al-Marhoon
authors.forename: Sheila
authors.initials: S
authors.lastname: Nunn
authors.forename: Roger W
authors.initials: RW
authors.lastname: Soames
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000942:Antigens, Bacterial / Q000502:physiology*; D001426:Bacterial Proteins / Q000502:physiology*; D005260:Female; D005753:Gastric Mucosa / Q000737:chemistry* / Q000382:microbiology* / Q000473:pathology; D016481:Helicobacter Infections / Q000473:pathology; D016480:Helicobacter pylori / Q000235:genetics*; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D012737:Sex Factors
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C080866:cagA protein, Helicobacter pylori