ABSTRACT
Classical swine fever virus (CSFV) causes a highly contagious disease among swine that has an important economic impact worldwide. CSFV strain LOM is an attenuated virus of low virulent strain of Miyagi isolated from Japan in 1956. Eight DNA fragments representing the genome of the CSFV strain LOM were obtained by RT-PCR. These were used to determine the complete nucleotide sequence and construct a full-length cDNA clone which was called Flc-LOM. Sequence analysis of the recombinant clone (Flc-LOM) revealed the presence of eight mutations, resulting in two amino acid substitutions, when compared to the parental sequence. RNA transcripts of both LOM and Flc-LOM were directly infectious in PK-15 cells. The rescued Flc-LOM virus grew more slowly than the parental virus, LOM, in the cells. Intramuscular immunization with Flc-LOM was safe and highly immunogenic in pigs; no clinical signs or virus transmission to sentinel animals were observed after 35 days. CSFV-specific neutralizing antibodies were detected 14 days post-infection. After challenge with the virulent CSFV strain SW03, pigs immunized with Flc-LOM were shown to be fully protected. Thus, our newly established infectious clone of CSFV, Flc-LOM, could serve as a vaccine candidate.
Subject(s)
Animals , Antibodies, Viral/blood , Base Sequence , Cell Line , Classical Swine Fever/immunology , Classical Swine Fever Virus/genetics , Cloning, Molecular , DNA, Complementary/genetics , Immunization/methods , Molecular Sequence Data , Neutralization Tests/veterinary , RNA, Viral/chemistry , Recombinant Proteins/immunology , Reverse Transcriptase Polymerase Chain Reaction/veterinary , Sequence Analysis, DNA , Specific Pathogen-Free Organisms , Swine , VirulenceABSTRACT
El cambio educativo hacia un modelo acorde con el Espacio Europeo de Educación Superior y la aparición de nuevos entornos virtuales de aprendizaje han propiciado el desarrollo de herramientas de transmisión del conocimiento denominadas objetos de aprendizaje. El presente artículo pretende establecer una panorámica de la definición y naturaleza de estos, los repositorios existentes y los programas informáticos disponibles para su creación.
The educational change to a model in agreement with the European Space of the Higher Education (ESHE) and the appearance of new virtual learning environments allowed the development of tools of knowledge transmission called learning tools. The aim of resent paper is to establish a panorama of the definition and origin of such tools, the available repositories and the information program also available for its creation.
ABSTRACT
0.05.In Group B,the inducing rate was 81.8 %(9/11) before intervention,while post intervention the rate was 9.1 %(1/11),the difference of inducing rate pro and post intervention was statistically significant at P0.05 before intervention,the difference was significant at P