In order to develop an experimental DNA vaccine for the prevention and treatment of hepatitis B virus infection, hepatitis B virus surface antigen (HBsAg) DNA was subcloned into an E. coli-eukaryotic cell shuttle vector and was expressed in the Baculovirus expression system. Intramuscular, intradermal, and intraperitoneal injections of 30 microg of the plasmid DNA expressing HBsAg induced humoral and cellular immune responses in ICR mice. The first IgG antibodies were detected after ten days and specific IgG antibody titers peaked after two months of a single intramuscular DNA injection. Anti-HBs antibody titers gradually increased and peaked at four months following intradermal DNA injection, and in case of intraperitoneal injection they peaked at seven months. Generation of HBs-specific helper T lymphocytes was also investigated through the production of interleukin-2 by T helper cells. Boosting effects of HBs DNA were investigated without much results. In general, DNA-mediated HBs immunization induced humoral and cellular immune responses in mice that appears to simulate immune responses in human during the course of HBV vaccination.

The purpose of this study was to investigate the mediating and moderating effects of teacher-child relationships on children's social behavior and peer preference. The participants were 508 children and 28 head teachers of their classes. Teachers measured the children's social behavior and the teacher-child relationships. Peer preference was measured by peer nomination. The association between prosocial behavior and peer preference was partially mediated by teacher-child conflict. The association between withdrawal, aggression and peer preference was fully mediated by teacher-child conflict. The moderating effects of teacher-child conflict were found between prosocial behavior and peer preference. In addition, teacher-child conflict moderated the association between physical aggression and peer preference. 주제어 (Keywords) : 또래 선호 (peer preference), 교사-유아 관계 (teacher-child relationships), 친사회성 (prosocial behavior), 위축성 (withdrawal), 공격성 (aggression)

No abstract

No abstract

No abstract