Objective:Express a human anti-HBsAg single chain antibody fragment(scFv)-consensus interferon (cIFN) fusion protein by bacterial expression system and analyse the function of the fusion protein.Methods:Human anti-HBsAg single chain monoclonal antibody cDNA encoding the variable regions of immunoglobulin from PBMC of Hepatitis B patient. Consensus interferon gene was produced by overlap PCR.A plasmid for production of cIFN-scFV fusion protein was constructed, then the expression vector pRA cIFN-scFV transformed with the E.coli strain BL21(DE3). The gene product was analysed SDS-PAGE and Western blotting, then was solubilized by guanidine hydyochloride, refolded by conventional dilution method, and purified using metal-chelating chromatography. The immune and functional analysis of the resulting fusion protein have been studied by ELISA,FACS(Flow cytometry),MTS assay and hemaglutination inhibition test.Results:The authors isolated and characterized the human anti-HBsAg single chain antibody fragment(scFv)-consensus interferon (cIFN) fusion protein. The resulting human anti-HBsAg scFv-cIFN fusion protein was bound to react with HBsAg and cIFN, this react show that highly specific and bioactivity.Conclusion:A human anti-HBsAg single chain antibody fragment(scFv)-consensus interferon (cIFN) fusion protein was produced by bacterial expression system in this study. This genetically engineered human anti-HBsAg scFv-cIFN fusion protein promises to be an important reagent for hepatitis B immunotherapy.

Background/Aims: Intestinal Behçet disease is typically associated with ileocecal punched-out ulcers and significant morbidity and mortality. Intestinal ultrasound is a noninvasive imaging technique for disease monitoring. However, no previous reports have compared intestinal ultrasound with endoscopic ulcer activity or histopathological findings for intestinal Behçet disease. We evaluated the usefulness of intestinal ultrasound for assessing the activity of ileocecal ulcers in intestinal Behçet disease. Methods: We retrospectively compared intestinal ultrasound findings with 73 corresponding endoscopic images and 6 resected specimens. The intestinal ultrasound findings were assessed for 7 parameters (bowel wall thickness, vascularity [evaluated using the modified Limberg score with color Doppler], bowel wall stratification, white-plaque sign [strong hyperechogenic lines or spots], mesenteric lymphadenopathy, extramural phlegmons, and fistulas), and endoscopic ulcer activity was classified into active, healing, and scar stages. Histopathological findings were evaluated by consensus among experienced pathologists. Results: Bowel wall thickness (P< 0.001), vascularity (P< 0.001), loss of bowel wall stratification (P= 0.015), and white-plague sign (P= 0.013) were significantly exacerbated in the endoscopic active ulcer stage. Receiver operating characteristic curve analysis revealed that a bowel wall thickness of > 5.5 mm (sensitivity 89.7%, specificity 85.3%) was potentially useful for detecting active lesions. When compared with histopathological findings, an increase in bowel wall thickness reflected the ulcer marginal ridge, and the white-plaque sign reflected the ulcer bottom. Conclusions Intestinal ultrasound is useful for monitoring intestinal ulcer activity in intestinal Behçet disease.