[Research progress on the characteristics of immune tolerant phase and antiviral therapy in children with chronic hepatitis B]

Whether or not children with chronic hepatitis B (CHB) in the immune-tolerant phase need to be treated is one of the hot clinical issues that have not yet been clarified. Thus, in order to make clinical antiviral treatment decisions in children with an immune tolerant phase, a comprehensive understanding of the natural history of HBV infection, as well as its relationship with disease progression and whether prompt treatment can alter the natural history and prognosis, is very important. To that end, this article reviews the research progress of clinical antiviral therapy in the immune-tolerant phase for children with chronic hepatitis B over the last decade, while also discussing the treatment's safety, effectiveness, and related immunological mechanisms, so as to clarify the next key step in research orientation, provide direct evidence-based medical evidence for hepatologists to better diagnose and treat, and ultimately improve the clinical cure rate.

[Cloning and sequence analysis of a gene encoding amastin from Leishmania major]

OBJECTIVE

To clone a gene encoding surface protein from Leishmania major.

METHODS

Using T. cruzi amastin DNA sequence as a reference, computer search was done on GenBank and dbEST databases by using BLAST path. A Leishmania major DNA library has been constructed and screened by in situ colony hybridization.

RESULTS

A 309nt DNA fragment from Leishmania major was found in dbEST. Leishmania major DNA library was screened using specific primers synthesized according to 309 nt DNA sequence, and a full-length coding sequence for Leishmania major amastin was cloned. The coding sequence consisted of 552 nt, and translated into 183 amino acid residues. The homology is 23.5% at amino acid sequence level between Leishmania major and T. cruzi amastins.

CONCLUSION

A full length amastin coding gene for Leishmania major has been cloned.