Inhibition of the replication of H9N2 influenza virus in vivo by short-term repeated oral administration of chicken interferon α / 生物工程学报

To evaluate the optimal administration frequency for interferon-α (IFN-α) and the effect of its combined use with inactive virus on chicken flocks, the prokaryotic expression plasmid pET-22b-ChIFN-α was constructed and transferred into Escherichia coli BL21(DE3) host bacteria to induce the expression of chicken IFN-α and to harvest recombinant proteins inclusion bodies. The expression of recombinant chicken IFN-α was confirmed by SDS-PAGE, and the results demonstrated that the chicken IFN-α (20 kDa) was highly expressed using the prokaryotic expression vector with a concentration of 0.2 mg/mL in the medium. Chicken IFN-α was diluted to 2.5×10⁴ U/fowls and administered to immunized specific-pathogen-free chickens orally in combination with inactivated H9N2 subtype influenza virus. Chicken that received chicken IFN-α were safe after three repeated immunizations (96 h). In addition, chicken IFN-α could induce higher levels of antiviral-related inducible genes in peripheral blood, spleen, and thymus of chicken flocks. The results of a challenge assay revealed that the lowest detoxification rates of chicken IFN-α ranged from three to five days, suggesting a higher capacity to resist H9N2 subtype avian influenza virus. The present study obtained the optimal immune frequency and immunization period for chicken IFN-α to provide theoretical support for the optimal clinical application of IFN-α.

The early toxic effect sensitive index of short-term-repeated exposure to cadmium chloride in male rats / 中国职业医学

OBJECTIVE: To observe the early adverse effect index caused by short-term-repeated exposure to cadmium chloride via oral perfusion in male rats. METHODS: Forty specific pathogen free healthy male SD rats were randomly divided into four groups: control group,low-,middle-and high-dose groups. The rats of low-,middle-and high-dose groups were treated with cadmium chloride 1. 11,3. 51 and 11. 06 mg/kg body weight,respectively,and the control group rats was treated with the same volume of ultra pure water,by gavage once a day for four weeks. During the experimental duration,the body weights of the rats were taken and activity status of the rats was observed. After the experiment,the rats were executed,and some indicators of main organ coefficients,blood routine,serum biochemical indexes,urine related effect indexes and bone mineral density were measured. RESULTS: During the experimental duration,rats of high-dose group showed the symptoms such as decreased activity,increase repose,move slowly and skin duller. Comparing with control group at the same time points,the body masses of the high-dose group of the 1-4 weeks were lower(P < 0. 05).After the experiment,comparing with control group,the weights of kidney and spleen of the high-dose group decreased significantly(P < 0. 05) and the liver coefficient increased significantly(P < 0. 05). The cadmium levels in blood,urine,liver,kidney and thighbone of the middle-and high-dose groups were higher than those of the control group(P < 0. 05).The red blood cell counts of the low-and middle-dose groups increased significantly(P < 0. 05). The level of hemoglobin of middle-and high-dose groups decreased(P < 0. 05),and the activity of alanine aminotransferase in high-dose groups increased significantly(P < 0. 05). Comparing with control group,the levels of urine α_1-microglobulin and urine β_2-microglobulin in urine of the middle-dose group were decreased(P < 0. 05) and the level of urine urea nitrogen increased(P < 0. 05),but there were no significantly changes of the above three indexes in the high-dose group(P >0. 05). There were no significant difference of the levels of N-acetyl-beta-D glucosaminidase in urine between control and treatment groups(P > 0. 05). Simultaneously,in high-dose group,the weight of thighbone,the bone calcium content and bone mineral density reduced significantly than those of the control group(P < 0. 05). CONCLUSION: Skeletal effects can be used as an early toxic effect sensitive index of short-term-repeated experiments exposure to cadmium chloride via oral perfusion in male rats.