Isolation and phylogenetic analysis of hemagglutinin gene of H9N2 influenza viruses from chickens in South China from 2012 to 2013

As part of our ongoing influenza surveillance program in South China, 19 field strains of H9N2 subtype avian influenza viruses (AIVs) were isolated from dead or diseased chicken flocks in Guangdong province, South China, between 2012 and 2013. Hemagglutinin (HA) genes of these strains were sequenced and analyzed and phylogenic analysis showed that 12 of the 19 isolates belonged to the lineage h9.4.2.5, while the other seven belonged to h9.4.2.6. Specifically, we found that all of the viruses isolated in 2013 belonged to lineage h9.4.2.5. The lineage h9.4.2.5 viruses contained a PSRSSRdownward arrowGLF motif at HA cleavage site, while the lineage h9.4.2.6 viruses contained a PARSSRdownward arrowGLF at the same position. Most of the isolates in lineage h9.4.2.5 lost one potential glycosylation site at residues 200-202, and had an additional one at residues 295-297 in HA1. Notably, 19 isolates had an amino acid exchange (Q226L) in the receptor binding site, which indicated that the viruses had potential affinity of binding to human like receptor. The present study shows the importance of continuing surveillance of new H9N2 strains to better prepare for the next epidemic or pandemic outbreak of H9N2 AIV infections in chicken flocks.

Model index observations in SIVmac251-infected rhesus macaques / 病毒学报

In this study, five rhesus macaques were inoculated intravenously with SIVmac251 to establish a model of simian autoimmune deficiency syndrome (SAIDS). Peripheral blood samples were collected at different time points to monitor changes in the total T cell number and T lymphocyte subset. Plasma viral loads, cytokine expression levels and anti-SIV antibody levels were also assayed to acquire certain basic indexes to evaluate disease progression in the rhesus macaque SAIDS model. During the acute stage of infection, plasma viral loads reached a peak at week 1 post-inoculation and lasted for approximately 3 to 44 weeks. The CD3+ CD4+ T lymphocyte count in peripheral blood also transitorily decreased. During the same period, the level of interferon-gamma show an increasing trend, whereas IL-12 levels decreased; IL-2, IL-4, IL-10 and TNF-alpha were maintained at normal levels or could not be detected. During the asymptomatic and ARC phases, plasma viral loads persisted above 10(4) RNA copies/mL and either increased or declined during the later stages of disease; CD3+ CD4+ counts showed a steadily declining trend and the ratio of CD4 to CD8 decreased during late-stage disease. Moreover, antibodies against viral proteins were detected in the plasma and showed a significant increasing trend, while there were no apparently changes in the levels of IFN-gamma, IL-12, IL-2, IL-4, IL-10 and TNF-alpha. In conclusion, the characteristics of the SIV animal models in our study are similar to those of patients with AIDS. Therefore, the rhesus macaque SIVmac251 infection models can be applied for further studies into AIDS.

Glycoprotein secreted by Absidia corymbifera is associated with apoptosis of human umbilical vein endothelial cells / 中华微生物学和免疫学杂志

Objective To partially purify the toxic factor secreted by A. corymbifera and to analyze the mechanism of A. corymbifera-induced human umbilical vein endothelial cell (HUVEC) apoptosis. Methods Glycoprotein secreted by A. corymbifera was purified by Con A Lectin chromatography. The influence of different protein fractions on HUVEC apoptosis was determined by flow eytometer. Both denaturing and nondenaturing deglycosylation of purified glycoprotein was performed and the ability of the protein moiety and carbohydrate moiety to induce HUVEC apoptosis was evaluated respectively. Activation of related caspases during A. corymbifera-induced apoptosis was analyzed by Western blot. The role of caspase-8 and -9 in HUVEC apoptosis was investigated using caspase inhibitors. Caspase inhibitors were used to stop the suppression of HUVEC viability by XTT assay. Results Flow cytometric analysis shows the total protein as well as the glycoprotein fraction of A. corymbifera may induce HUVEC apoptosis in a dose dependent manner. In contrast, similar activity was not observed in the non-glycoprotein fraction. Neither deglycosylated protein nor carbohydrate moiety is able to induce HUVEC apoptosis alone. In the apoptotic signaling pathway, caspase9, caspase-3 and cytochrome C were activated significantly, except caspase-8. Moreover, caspase-9 inhibitor, instead of caspase-8 inhibitor, completely abrogates A. corymbifera-induced HUVEC apoptosis. Caspase9 and caspase-3 inhibitors completely waived the suppression of HUVEC viability by A. corymbifera. Conclusion Glycoprotein secreted by A. corymbifera is associated with HUVEC apoptosis. Intact glycoprotein is essential for the apoptotic progress. Intrinsic apoptotic signaling pathway mediates A. corymbifera-induced HUVEC apoptosis.

Effect of Gengnianchun Recipe on learning memory function and hippocampal cholinergic system in ovariectomized rats / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To evaluate the effect of Gengnianchun Recipe (GNC) on learning memory function and its regulatory effect on hippocampal cholinergic system in ovariectomized rats.</p><p><b>METHODS</b>Female rats 10-12 months old were randomized into 5 groups, the sham-operation group, the model group treated with normal saline, the positive control group treated with Nilestriol, and the two GNC groups treated with high and low dose GNC respectively. A little fat around ovary was cut in the sham-operation group. The treatment lasted for 12 weeks after ovariectomy. Changes of learning memory function were tested by Morris water maze; serum level of estradiol (E2) was measured by chemical fluorescent method; hippocampal acetylcholinesterase (AChE) mRNA was determined with Real-time PCR; and the activities of acetylcholine (ACh), AChE and choline acetyltransferase (ChAT) in hippocampus were detected by immunohistochemistry respectively.</p><p><b>RESULTS</b>Twelve weeks after ovariectomy, serum E2 and learning memory function markedly decreased in the ovariectomized rats (P < 0.01, P < 0.05). Nilestriol and high dose GNC showed an effect in improving the symptoms of learning memory functional deprivation and elevating the activities of hippocampal ACh, AChE and ChAT (all P < 0.05).</p><p><b>CONCLUSION</b>GNC can improve learning memory function of ovariectomized rats, and its mechanism might be realized by regulating the cholinergic system in hippocampus.</p>

Observation on Rhesus monkeys infected second time with H5N1 avian influenza virus / 病毒学报

Rhesus monkeys with high specific H5N1 antibody were inoculated the second time with H5N1 virus, the result of the second time H5N1 inoculation and the effect of first time H5N1 inoculation on second inoculation was evaluated. Monkeys of NO. 3, NO. 4, NO. 5 were inoculated with H5N1 allantoic fluid and NO. 6 with noninfectious allantoic fluid by intratracheal thyrocricoid puncture. Three months later, NO. 4, NO. 5, NO. 6 monkeys were infected with 7 ml TCID50 10(4.875) H5N1 allantoic fluid and NO. 3 monkey with 7 ml noninfectious allantoic fluid at the same time by the same method. Clinical symptoms were recorded and antibody response was detected by ELISA. NO. 3, NO. 4, NO. 6 monkeys were killed after 72 h post infection and NO. 5 monkey was killed after 7 days post infection. Pathologic changes of the infected monkeys' lung were examined by HE staining,immunohistochemistry and the virus in lung was detected by RT-PCR. Results showed that NO. 3, NO. 4, NO. 5 monkeys still retained high level of specific antibody, H5N1 virus only could be detected in NO. 6 monkey's lung by immunohistochemistry and RT-PCR ,and the lung of NO. 6 monkey injured worst . It can be concluded that Rhesus monkeys inoculated with H5N1 avian influenza A virus at the first time could retain a high level of specific antibody in 90 days and the clinical symptom had almost recovered, the ability of Rhesus monkeys to resist second infection of H5N1 virus was enhanced notably at that moment.