title: [The relationship between vac A genotype of Helicobacter pylori clinical isolate and gastric cancer and precancer].
abstract: OBJECTIVE
  To analyze the relationship between vac A genotype of Helicobacter pylori (Hp) and gastric cancer and precancer in Xi'an area.
  
  
  METHODS
  To establish the stock of Hp clinical isolates and perform vac A gene typing of Hp isolates by PCR.
  
  
  RESULTS
  192 Hp clinical strains are isolated from the antrum of 259 patients. In them, type s1 is 174 strains (90.6%); s2 is 18 stains (9.4%). Type m1 and m2 is 99 (51.6%) and 93 (48.4%) respectively. All strains are s1 or s2 and m1 or m2. In gastric cancer group, the expression of type s1 is 94.5% and s1a is more than s1b (P < 0.05). There is no difference between type m1 and m2. In gastritis group, type s1 is 89.8%, s1a is almost equal to s1b and no difference between m1 and m2.
  
  
  CONCLUSIONS
  Type s1 is the main expression in both gastric cancer group and gastritis group. Expression of type s1a is higher than s1b. We can't determine it is a malignant index of gastrointestinal diseases. We need to research it extensively.
authors.affiliation: Department of Gastroenterology, First Hospital, Xi'an Jiaotong University, Xi'an 710063, China.
authors.forename: W
authors.initials: W
authors.lastname: Qiao
authors.forename: J
authors.initials: J
authors.lastname: Hu
authors.forename: K
authors.initials: K
authors.lastname: Wu
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics*; D005838:Genotype; D016480:Helicobacter pylori / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D011230:Precancerous Conditions / Q000382:microbiology*; D013274:Stomach Neoplasms / Q000382:microbiology*
chemical_list: D001426:Bacterial Proteins; C074689:VacA protein, Helicobacter pylori