The intrinsic fluorescence spectrum of dilute gastric juice as a novel diagnostic tool for gastric cancer.

OBJECTIVE: To investigate the intrinsic fluorescence spectrum of gastric juice as a diagnostic method for gastric cancer. METHODS: We collected gastric juice by gastroscopy in 1,870 patients from May 2001 to March 2006, of whom 202 were involved in a preliminary test, 162 in experimental optimization and 1,506 in clinical verification. The best dilution and pH value were chosen in the experimental optimization phase. Clinical verification was based on optimized samples. Intrinsic fluorescence spectra were measured in all samples with a fluorescence spectrophotometer using an excitation wavelength of 288 nm. RESULTS: The first peak of fluorescence intensity (P(1) FI) of the intrinsic fluorescence spectrum was significantly higher in gastric juice from patients with gastric cancer than from those with benign lesions. There was no significant difference in the P(1) FI differences between patients with benign and malignant lesions with samples diluted by 20-fold to 80-fold and from pH 9 to pH 11. Clinical verification in 1,506 patients showed that P(1) FI ≥ 76.5 was the optimal cut-off on the receiver operating characteristic curve for diagnosing gastric cancers: sensitivity was 83.2%, specificity 80.7% and accuracy 82.0%. CONCLUSIONS: P(1) FI of the intrinsic fluorescence at 288 nm is significantly higher in patients with gastric cancers than in individuals with benign lesions. As a clinical indicator of gastric cancer, its sensitivity, specificity and accuracy were high.

[Changes of gastric mucosa histopathology after Helicobacter pylori eradication].

OBJECTIVE: To investigate the relationship between Helicobacter pylori (Hp) infection and gastric cancer through the changes of gastric mucosa histopathology within 5 years after Hp eradication in Hp-positive subjects in the high incidence region of gastric cancer. METHODS: One thousand and six adults were selected from general population in Yantai, Shandong Province, the high incidence region of gastric cancer. Gastroscopy and CLO test were performed in all subjects. Biopsy samples from the gastric antrum and body were obtained for histology and assessment of Hp infection. All the Hp-positive subjects were then randomly divided into two groups: treatment group receiving OAC triple therapy and placebo as controls. These subjects were endoscopically followed up in the second and fifth year. In this article, we compared the endoscopic appearance and histology of the biopsy specimens from the same site obtained at the first and final visit. Statistical analysis was done by chi(2) test. RESULTS: All the 552 Hp-positive subjects were randomly divided into treatment group or control group, 276 in each. During the five-year follow-up, the number of patients who continued to be negative or positive for Hp was 161 and 198, respectively. Statistical analysis revealed that: (1) At the initial visit, there were no significant differences in the severity and activity of inflammation between the biopsy specimens from the antrum (P = 0.105) and body (P = 0.084) in both groups. But the proportion of atrophy and intestinal metaplasia in the antrum was much higher than that in the body (P = 0.000). (2) The severity and activity of inflammation in both the antrum and body were markedly reduced after Hp eradication (P = 0.000). (3) Within the five years after Hp eradication, intestinal metaplasia in the antrum regressed or had no progression, while the proportion of intestinal metaplasia in the Hp-positive group increased significantly (P = 0.032). (4) After Hp eradication, the atrophy in both the antrum and body had no significant regression. P value was 0.223 and 0.402, respectively. CONCLUSIONS: Hp eradication results in remarkable reduction in the severity and activity of chronic gastritis, marked resolution of intestinal metaplasia in the antrum. On the other hand, continued Hp infection leads to progressive aggrevation of atrophy and intestinal metaplasia.

[The value of autofluorescence spectrum analysis of gastric juice in diagnosing gastric carcinoma: a preliminary result].

OBJECTIVE: To reveal the difference of autofluorescence spectrums of gastric juice derived from malignancy and benignancy for screening and diagnosis of gastric carcinoma. METHOD: Gastric juice from 202 patients with different gastric diseases were collected, then detected their autofluorescence spectrums (the excitation wavelength is 288 nm, whereas the range of emission wavelength is 300 - 800 nm) after diluted by 1:10. The diagnostic model for gastric cancer was made by Classification and Regression Trees V2.0 software. RESULTS: There were three peaks (the emission wavelength were 320 - 360 nm, 576 nm and 670 - 690 nm respectively) in the autofluorescence spectrums of all patients, though the intensity of the first peak (with the emission wavelength of 320 - 360 nm) were enhanced distinctively in malignance than those in benignancy. The diagnostic model's sensitivity and specificity of prior probability were 91.4% and 83.2% respectively, whereas the sensitivity and specificity of posterior probability were 85.7% and 82.6%. CONCLUSION: Detection of autofluorescence spectrum of gastric juice has great prospect in the diagnosis and screening gastric carcinoma.