ABSTRACT
The highly pathogenic avian influenza (HPAI) H5N1 virus has caused several outbreaks in domestic poultry. Despite great efforts to control the spread of this virus, it continues to evolve and poses a substantial threat to public health because of a high mortality rate. In this study, we sequenced whole genomes of eight H5N1 avian influenza viruses isolated from domestic poultry in eastern China and compared them with those of typical influenza virus strains. Phylogenetic analyses showed that all eight genomes belonged to clade 2.3.2.1 and clade 7.2, the two main circulating clades in China. Viruses that clustered in clade 2.3.2.1 shared a high degree of homology with H5N1 isolates located in eastern Asian. Isolates that clustered in clade 7.2 were found to circulate throughout China, with an east-to-west density gradient. Pathogenicity studies in mice showed that these isolates replicate in the lungs, and clade 2.3.2.1 viruses exhibit a notably higher degree of virulence compared to clade 7.2 viruses. Our results contribute to the elucidation of the biological characterization and pathogenicity of HPAI H5N1 viruses.
Subject(s)
Animals , China , Influenza A Virus, H5N1 Subtype , Genetics , Virulence , Influenza in Birds , Virology , Mice, Inbred BALB C , Phylogeny , PoultryABSTRACT
This paper is to report the study of the pharmacokinetics of a fusion protein TAT-haFGF(14-154) for human acidic fibroblast growth factor and transcriptional activator protein in rat plasma, and the investigation of their penetration across blood-brain barrier in mice and rats, in order to provide a basis for clinical development and treatment of Alzheimer's disease. Enzyme-linked immunosorbent assay (ELISA) was used to determine concentration of TAT-haFGF(14-154) in rat plasma and in mouse brain homogenate; and immunohistochemistry was used to analyze the distribution in brain. The concentration-time curve fitted two-compartment open model which was linear kinetics elimination after a single intravenous injection of TAT-haFGF(14-154) in rat at the dose of 300 microg x kg(-1). The half life time was 0.049 +/- 0.03 h for distribution phase and 0.55 +/- 0.05 h for elimination phase, and the weight was 1/C2. The result showed that TAT-haFGF(14-154) could be detected in the brain by ELISA and immunohistochemistry, the elimination of TAT-haFGF(14-154) in rat was swift, and TAT-haFGF(14-154) could penetrate across the blood-brain barrier, distribute in pallium and hippocampus and locate in the nucleus.
Subject(s)
Animals , Female , Male , Mice , Rats , Blood-Brain Barrier , Metabolism , Brain , Metabolism , Cell Nucleus , Metabolism , Cerebral Cortex , Metabolism , Fibroblast Growth Factor 1 , Pharmacokinetics , Gene Products, tat , Pharmacokinetics , Hippocampus , Metabolism , Injections, Intravenous , Rats, Sprague-Dawley , Recombinant Fusion Proteins , PharmacokineticsABSTRACT
<p><b>OBJECTIVE</b>To establish a convenient method for preparing rabbit models of ischemic cerebral infarction using autologous clot embolism.</p><p><b>METHODS</b>Ischemic cerebral infarction was induced in rabbits by embolizing the middle cerebral artery using autologous clot emboli. Clinical and histological observations were carried out to evaluate the validity of the animal model.</p><p><b>RESULTS</b>Hemiplegia of different severities was observed in the rabbits after the operation. TTC and HE staining of the brain sections confirmed ischemic cerebral infarction 6 h after obstructing the middle cerebral artery with the autologous clot emboli.</p><p><b>CONCLUSION</b>Embolizing the middle cerebral artery using the autologous emboli is convenient to induce focal ischemic cerebral infarction in rabbits. This model has practical value in the study on the mechanism of ischemic cerebrovascular disease and in developing new strategies for prevention and treatment of the relevant diseases in human.</p>
Subject(s)
Animals , Male , Rabbits , Cerebral Infarction , Disease Models, Animal , Infarction, Middle Cerebral Artery , Random AllocationABSTRACT
<p><b>BACKGROUND</b>H3N2 subtype influenza A viruses have been identified in humans worldwide, raising concerns about their pandemic potential and prompting the development of candidate vaccines to protect humans against this subtype of influenza A virus. The aim of this study was to establish a system for rescuing of a cold-adapted high-yielding H3N2 subtype human influenza virus by reverse genetics.</p><p><b>METHODS</b>In order to generate better and safer vaccine candidate viruses, a cold-adapted high yielding reassortant H3N2 influenza A virus was genetically constructed by reverse genetics and was designated as rgAA-H3N2. The rgAA-H3N2 virus contained HA and NA genes from an epidemic strain A/Wisconsin/67/2005 (H3N2) in a background of internal genes derived from the master donor viruses (MDV), cold-adapted (ca), temperature sensitive (ts), live attenuated influenza virus strain A/Ann Arbor/6/60 (MDV-A).</p><p><b>RESULTS</b>In this presentation, the virus HA titer of rgAA-H3N2 in the allantoic fluid from infected embryonated eggs was as high as 1:1024. A fluorescent focus assay (FFU) was performed 24-36 hours post-infection using a specific antibody and bright staining was used for determining the virus titer. The allantoic fluid containing the recovered influenza virus was analyzed in a hemagglutination inhibition (HI) test and the specific inhibition was found.</p><p><b>CONCLUSION</b>The results mentioned above demonstrated that cold-adapted, attenuated reassortant H3N2 subtype influenza A virus was successfully generated, which laid a good foundation for the further related research.</p>