[Fluorescent quantitative real-time PCR for detection of Schistosoma japonicum].

OBJECTIVE: To establish a sensitive and specific fluorescent quantitative real-time PCR method for the detection of Schistosoma japonicum. METHODS: Based on 18SrRNA sequence of S. japonicum, a PCR assay was established. The 1450bp fragment was amplified and cloned into T vector which was subsequently transformed into E.coli DH5alpha. Following extraction and identification, the positive recombinant plasmid was used as quantitative template to generate standard curve. Reproducibility and specificity of the assay was determined as well. RESULTS: The standard curve established by recombinant plasmid showed a fine linear relationship between threshold cycle (Ct) and template concentration, and the correlation coefficient was 0.998 7. Using the coefficient of variation (CV) value to evaluate the reproducibility, at the template concentration of 1.05 x 10(7)-1.05 x 10(3) copies per reaction, the average Ct values were 17.55,20.93,24.32, 27.59, 30.95, and the CV values were 1.31%, 1.53%, 0.90%, 1.85% and 0.90% respectively. In the evaluation of the reproducibility, the mean interassay CV was 1.27% and no unspecific amplification was observed. The real-time PCR assay could quantitatively detect as low as 6.15 pg S. japonicum genome in the study(Ct < or = 30.95), and the detection should be done in 3 hours. CONCLUSION: A fluorescent quantitative real-time PCR for the detection of S. japonicum is developed, which is rapid, sensitive and specific for pathogen detection.

[Relationship between hepatitis B virus in gastric mucosa and syndrome of disharmony between liver and stomach in patients with chronic hepatitis B].

OBJECTIVE: To study the relationship between the infection of hepatitis B virus (HBV) in gastric mucosa and the syndrome of disharmony between liver and stomach. METHODS: Subjects were divided into 2 groups: 30 patients with chronic hepatitis B (CHB) and the syndrome of disharmony between liver and stomach in hepatitis group, and 30 patients with chronic gastritis and the syndrome of disharmony between liver and stomach in gastritis group. Liver function and the markers of HBV were detected. The contents of HBV-DNA in serum and in gastric mucosa were assayed respectively by fluorescence quantitative polymerase chain reaction (FQ-PCR). RESULTS: (1) The incidence of gastric mucosal lesion in hepatitis group was up to 96.7% (29/30). (2) Scores of the syndrome of disharmony between liver and stomach in hepatitis group were significantly lower than those in gastritis group (P<0.05). The positive rates of HBV-DNA in serum, gastric fundus, body and antrum were 56.7%, 76.7%, 76.7% and 70.0%, respectively. (3) A positive correlation was found not only among the content of HBV-DNA in serum and the contents of HBV-DNA in gastric mucosa (r=0.66-0.94, P<0.01), but also among the contents of HBV-DNA in serum, gastric mucosa and the total score of the syndrome of disharmony between liver and stomach in hepatitis group (r=0.36-0.52, P<0.05). CONCLUSION: The infection of HBV is involved in the syndrome of disharmony between liver and stomach. Gastric mucosal lesion is universal in CHB patients with the syndrome of disharmony between liver and stomach.