A novel approach for the detection of early gastric cancer: fluorescence spectroscopy of gastric juice.

OBJECTIVE: This study aimed to investigate the efficacy of fluorescence spectroscopy of gastric juice for early gastric cancer (EGC) screening. METHODS: Gastric juice was collected from 101 participants who underwent endoscopy in the Outpatient Endoscopy Center of Peking University Third Hospital. The participants were divided into three groups: the normal mucosa or chronic non-atrophic gastritis (NM-CNAG) group (n = 35), advanced gastric cancer (AGC) group (n = 33) and EGC group (n = 33). Fluorescence spectroscopic analysis was performed in all the gastric juice samples and the maximum fluorescence intensity of the first peak (P1 FI) was measured. RESULTS: The mean fluorescence intensity of P1 FI of gastric juice in AGC (92.1 ± 10.7) and EGC (90.8 ± 12.0) groups was significantly higher than that in the NM-CNAG group (55.7 ± 7.5) (AGC vs NM-CNAG, P = 0.006 and EGC vs NM-CNAG, P = 0.015, respectively). The areas under the receiver operating characteristic curves for the detection of AGC and EGC were 0.681 (95% confidence interval [CI] 0.553-0.810, P = 0.010) and 0.655 (95% CI 0.522-0.787, P = 0.028). With the P1 FI of ≥47.7, the sensitivity, specificity and accuracy for detecting EGC were 69.7%, 57.1% and 63.2%, respectively. CONCLUSIONS: The enhancement of P1 FI of gastric juice occurs at the early stage of gastric cancer. Fluorescence spectroscopy of gastric juice may be used as a novel screening tool for the early detection of gastric cancer.

[The effects of pronase on drugs concentrations for treatment of Helicobacter pylori infection in gastric tissue].

OBJECTIVE: To evaluate the effect of pronase on amoxicillin and metronidazole concentrations in gastric tissue. METHODS: C57BL/6 mice were randomly divided into experimental group (n = 70) and control group (n = 70). Amoxicillin (28.6 mg/kg), metronidazole (22.5 mg/kg) and omeprazole (138.2 mg/kg) were administered orally to C57BL/6 mice, combined with pronase (110 mg/kg) or same amount of sterile PBS. Gastric tissue and blood plasma samples were taken at 10 point-in-time (7 mice/time) from 15 min up to 360 min after administration. Concentrations of amoxicillin and metronidazole were detected by high performance liquid chromatography. Gastritis index of gastric mucosa (hematoxylin-eosin staining) and the gastric tissue expressions of mucin 5AC (Western blot) were detected at 120 min and 360 min after administration. RESULTS: The time to peak concentration of amoxicillin and metronidazole in gastric tissue appeared earlier than that in blood plasma (15 min vs 60 min). Tissue concentrations of amoxicillin and metronidazole of experimental group were significantly higher than those of control, and they were mainly at 15 min to 90 min (P < 0.05). Plasma concentrations of amoxicillin and metronidazole of experimental group at 15 min and 30 min were higher than those of control (P < 0.05). There was no difference in gastritis index between experimental group and control at 120 min and 360 min after administration (0.28 ± 0.18 vs 0.14 ± 0.14, P > 0.05; 0.43 ± 0.20 vs 0.28 ± 0.18, P > 0.05). The expressions of mucin 5AC in experimental group were lower than those of control (0.036 ± 0.006 vs 0.197 ± 0.058; P < 0.05; 0.039 ± 0.008 vs 0.208 ± 0.072, P < 0.05). CONCLUSIONS: Pronase can significantly enhance the drugs penetration from mucus into gastric tissue. Concentrations of amoxicillin and metronidazole of experimental group in local gastric tissue and plasma are higher than those of control, especially in improving concentrations of gastric tissue and prolongation of exposed time.

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.

[Significance of changes in plasma lipid peroxide levels in critically ill patients after liver transplantation].

OBJECTIVE: To investigate the relationship between plasma lipid peroxide (LPO) levels and prognosis in critically ill patients after liver transplantation. METHODS: Plasma LPO levels were measured in 18 patients within 21 days after liver transplantation, and their relations to the prognosis were analyzed. RESULTS: Plasma LPO levels were markedly elevated in patients before state of illness got severe, especially in those with fatal outcome. The peak LPO levels were much higher in non-survivors than in survivors, and mortality rate in patients whose plasma LPO exceeding 10 micromol/L (5/6 cases) was significantly higher than those under 10 micromol/L (1/12 cases, P<0.01). The mortality rate in patients with daily fluctuation range of plasma LPO levels over 1.2 micromol.L(-1).d(-1) was higher than those under 1.2 micromol.L(-1).d(-1), and the difference was significant between two groups (P<0.01). CONCLUSION: Measurement of plasma LPO level might be of clinical significance to properly judge the critically ill conditions, and it can be used as routine examination for patients after liver transplantation.

[Evaluation oxygen free radicals related index before liver transplantation to forejudge prognosis].

OBJECTIVE: To research the relationship of oxygen free radicals related index before liver transplantation with prognosis. METHODS: Lipid peroxide (LPO), total antioxidant capacity (TAC), nitric oxide (NO) and total bilirubin (T-BIL) in blood from 18 patients were measured before liver transplantation, and the relationship with prognosis was analyzed. RESULTS: The blood LPO of death group was (17.13+/-4.16) micromol/L, it was obviously higher than that of survival group (7.97+/-3.52) micromol/L (P<0.05). The blood TAC of survival group was (38.05+/-19.13) kU/L, it was higher than that of death group (32.54+/-3.07) kU/L, but there was no obvious difference(P>0.05). There was no obvious difference between the blood NO of death group was (50.80+/-14.80) micromol/L, and survive group was (150.46+/-19.54) micromol/L (P>0.05). The blood T-BIL of death group was (425.98+/-214.18) micromol/L, it was obviously higher than that of survival group (172.10+/-144.32) micromol/L (P<0.05). So the blood LPO and TAC were chosen as the index to forejudge prognosis, and an equation was established to forecast if the patient would be death or survive: Y(1)=0.329 0 X(1)+0.099 8 X(2)-3.9040, Y(2)=1.352 0 X(1)-0.0500 X(2)-11.4640, X(1) represented serum LPO, X(2) represented serum TAC. 100.0 percent accuracy was forecasted in the survival group by the equation, 83.3 percent accuracy was in the death group. The overall patients were forejudged 94.4 percent accurately. CONCLUSION: Measuring LPO and TAC in blood maybe forejudging prognosis properly and can be used as routine examination before liver transplantation. The equation is preferable to forejudging prognosis, it can be used to choose from high risk patients to improve survival rate of the patients after operation. Therefore, it is valuable in clinical practise.

[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.