[The optimal thresholds of the quantitative fecal immunochemical test for opportunistic screening of colorectal neoplasia].

Objective: To investigate the significance of quantitative fecal immunochemical test (FIT) for opportunistic screening of colorectal neoplasia, and to propose the most optimal thresholds to improve the screening level of early colorectal neoplasia. Methods: The opportunistic screening participants were recruited from the Department of Gastroenterology & GI Endoscopy Center of the Seventh Medical Center of PLA General Hospital, and stool sample was collected before colonoscopy and the quantitative FIT was analyzed by OC-MICRO analysator for each patient. We assessed test performance in detecting colorectal neoplasia (advanced adenoma and CRC)with different thresholds on sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV). Results: A total of 1 448 objects were enrolled in this study, including 714 male (49.3%)and 734 female (50.7%).All participants were classified according to the result of colonoscopy and pathology, and 242 cases of colorectal neoplasia were found, containing 157 advanced adnoma and 85 colorectal cancer. The FIT threshold increased from 50 µg/L to 200 µg/L, while the positivity rate dropped from 11.5% to 8.6% and the sensitivity in detecting colorectal neoplasia dropped from 47.9% to 38.8%. However, the specificity increased from 96.8% to 98.2% and the positive predictive value increased from 82.3% to 87.0%.The miss rate of colorectal cancer increased from 11.8% (n=10) to 17.6% (n=15) along with the increase in FIT thresholds, but the miss rate of 100 µg/L and 150 µg/L was the same as 12.9% (n=11). Conclusions: Quantitative FIT,which is simple and fast,with the threshold of 100 µg/L for opportunistic screening, has a high sensitivity and specificity for the diagnosis of colorectal neoplasia,and is an important index in screening and diagnosis of colorectal neoplasia.

[A study of the relationship between expression of IGF-II, IGF-IIR, HBxAg and the DNA ploidy, cell cycle of hepatocytes in hepatocarcinoma].

In order to study the role of insulin-like growth factor II (IGF-II) in the development of hepatocarcinoma (HCC), the expression of IGF-II, IGF-II receptor (IGF-IIR) and HBxAg in HCC was studied with immunohistochemistry (PAP method). Meanwhile DNA ploidy and S-phase fraction of hepatocytes were analyzed with flow cytometry. The results were as follows: (1) IGF-II, IGF-IIR and HBxAg showed positive staining simultaneously in the tumor tissues of 93% (n = 15) of the HCC cases with chronic liver disease and with positive evidence of HBV; (2) The mean S-phase incidence in tissues of IGF-II positive HCC was 28.6 +/- 6.4%; this was higher than 12.8 +/- 2.4% in the IGF-II negative tumors (P < 0.05); (3) The incidence of DNA-aneuploidy in IGF-II positive liver tissues was 100% (10/10); this was higher than 60% (6/10) in IGF-II negative liver tissues (P < 0.05). It is suggested that IGF-II might play an important role in the development of HCC when there is evidence of HBV and chronic liver disease involvement. IGF-II positive staining HCC have increased proliferative activity as compared with IGF-II negative staining tumors.

[An analysis of HCV infection by using recombinant HCV antigen C11 and C7].

The recombinant protein C11 derived from the C region of HCV genome and C7 derived from the nonstructural region NS3 of the HCV genome were used in ELISA to study 442 cases of liver diseases, including chronic hepatitis, cirrhosis and hepatocellular carcinoma in Beijing District. It was found that HBV infection was more prevalent than HCV infection in this district. Both liver cirrhosis and hepatocellular carcinoma were more related to the superinfection of HBV and HCV rather than HBV infection alone or HCV infection alone. It is suggested that there may be some interaction between the HBV and HCV to worsen the prognosis of these patients.

Ultrastructural study on extrahepatic infection of duck hepatitis B virus in ducks.

Kidney and pancreas tissues from congenitally infected Ma ducks with duck hepatitis B virus (DHBV) were examined by immunohistochemical staining technique and electron microscopy. The immunostaining showed that DHBV antigen was localized in the cytoplasm of tubular epithelial cells of kidney and acinar cells of pancreas of infected ducks. Under electron microscope, we found that complete and incomplete DHBV particles existed in the dilated cisternae of rough endoplasmic reticulum of both the cells. The size of complete and incomplete virus particles was nearly uniform in both the cells, 50-65 nm and 40-50 nm in diameter respectively. Therefore, extrahepatic infection and replication of DHBV were directly demonstrated ultrastructurally.

Ultrastructural study of hepatitis B virus in biliary epithelial cells of duck liver.

Liver specimens from the Shanghai Ma ducks congenitally infected with duck hepatitis B virus (DHBV) were examined by immunohistochemical technique and electron microscopy. All the 12 serum DHBV positive ducks showed varying degrees of positive straining in hepatocytes. In 8 of the 12 ducks, DHBV antigen was discovered in the cytoplasm of biliary epithelial cells. Conventional electron microscopy revealed two kinds of virus particles in the biliary epithelial cells: 1. the incomplete virus, 40-50 nm in diameter and spherical in shape with an outer membrane, located mainly in the dilated cisternae of rough endoplasmic reticulum of the cells in large amounts; 2. the complete virions, 55-60 nm in diameter, were spherical with an outer membrane and located mainly in the cytoplasmic vesicles in small amount. We believe the particles found in the biliary epithelial cells in this study were DHBV particles. It is most likely that the infection and replication of DHBV not only take place in the liver cells but also in the biliary epithelial cells.

[Chronic active hepatitis with superinfection of delta virus and hepatitis B virus: treatment with Chinese traditional medicine].

Among the 136 patients of HBsAg positive chronic hepatitis admitted from November 1986 to June 1988, 110 patients gave consent to have liver biopsy and out of the 110 liver biopsies 86 were confirmed histologically to be chronic active hepatitis. After screening the 86 patients twice with ELISA (ABBOTT ANTI-DELTA EIA), 26 (30.23%) showed positive results twice. Though it was reported that the incidence of delta hepatitis infection is very low in the HBsAg carriers in Beijing area, the incidence of superinfection of delta hepatitis on chronic active hepatitis B seems to be considerably high (30.23%) as shown in this study. Histological examination revealed that in the liver of patients with superinfection of delta hepatitis on chronic active hepatitis (26 cases) there were more severe changes and more eosinophilic degeneration than in the liver of patients without superinfection (58 cases). The patients were allocated to 3 groups at random. Eleven cases of chronic active hepatitis, with superinfection were treated with Chinese traditional medicine Xiao Chai Hu Tang (XCHT), 5 cases with biphenyl dimethyl dicarboxylate (BDD) and 10 cases with XCHT + BDD. It was noted that after 3 months of treatment, in the XCHT group, HBeAg became negative in 2/3, anti-HBe converted to positive in 2/8 and HBV-DNA converted to negative in 2/2. SGPT became normal in 8/8. XCHT showed a fairly good result and deserves further study.

Synthesis of a recombinant DNA-derived HBV e antigen and its application in diagnosis.

The gene coding for HBV e antigen (HBeAg) and core antigen (HBeAg) are located in the C region of the HBV genome. In this paper 1.8 kb BamHI-EcoRI DNA fragment carrying HBc gene from adw2 HBV DNA was digested with Bal31 and HapII, a series of fragment with different length were produced and inserted into pUR222 and pUC18 vectors to construct various recombinant plasmids. Two new recombinants able to direct high level synthesis of HBeAg in E. coli were obtained. Recombinant HBeAg was then purified by DEAE chromatography and affinity chromatography. The preparation obtained were identified by electrophoresis and immunochemical analysis. Molecular weight of the recombinant HBeAg determined by SDS-PAGE was about 38 kd. It is considered to be a dimer of two fused antigen molecules in size of 19 kd. Bacterial extracts prepared from cells harboring one of the constructed plasmids have been used successfully as a diagnostic reagent for the detection of HBeAg and anti-HBe in human sera by ELISA.