A single dose of inactivated oil-emulsion bivalent H5N8/H5N1 vaccine protects chickens against the lethal challenge of both highly pathogenic avian influenza viruses

In this study, two highly pathogenic avian influenza (HPAI) H5N8 viruses were isolated from chicken and geese in 2018 and 2019 (Chicken/ME-2018 and Geese/Egypt/MG4/2019). The hemagglutinin and neuraminidase gene analyses revealed their close relatedness to the clade-2.3.4.4b H5N8 viruses isolated from Egypt and Eurasian countries. A monovalent inactivated oil-emulsion vaccine containing a reassortant virus with HA gene of the Chicken/ME-2018/H5N8 strain and a bivalent vaccine containing same reassortant virus plus a previously generated reassortant H5N1 strain (CK/Eg/RG-173CAL/17). The safety of both vaccines was evaluated in specific-pathogen-free (SPF) chickens. To evaluate the efficacy of the prepared vaccines, 2-week-old SPF chickens were vaccinated with 0.5 mL of a vaccine formula containing 10⁸/EID₅₀ /dose from each strain via the subcutaneous route. Vaccinated birds were challenged with either wild-type HPAI-H5N8 or H5N1 viruses separately at 3 weeks post-vaccine. Results revealed that both vaccines induced protective hemagglutination-inhibiting (HI) antibody titers as early as 2 weeks PV (≥5.0 log₂). Vaccinated birds were protected clinically against both subtypes (100 % protection). HPAI-H5N1 virus shedding was significantly reduced in birds that were vaccinated with the bivalent vaccine; meanwhile, HPAI-H5N8 virus shedding was completely neutralized in both tracheal and cloacal swabs after 3 days post-infection in birds that had been vaccinated with either vaccine. In conclusion, the developed bivalent vaccine proved to be efficient in protecting chickens clinically and reduced virus shedding via the respiratory and digestive tracts. The applicability of the multivalent avian influenza vaccines further supported their value to facilitate vaccination programs in endemic countries.     

雁行模式对中国产业及国际分工的影响

通过介绍、分析雁行模式,来展现东亚地区自70年代以来的主要国际分工情况.随后阐释该分工模式存在的不足,与受到的来自外界的冲击.在这种内外因素的作用下,这种国际分工模式被现实实践有效扬弃,形成了“后雁行模式”.最后,立足“雁行模式”的变化与国际分工的变化,探讨其对中国产业发展与国际分工的影响.     

Concentrations in plasma and selected tissues of marbofloxacin after oral and intravenous administration in Bilgorajska geese (Anser anser domesticus)

ABSTRACT

Aims: To determine the pharmacokinetics and tissue depletion of 2?mg/kg marbofloxacin (MBX) in Bilgorajska geese (Anser anser domesticus) after I/V and oral administration, to calculate the daily dose from experimental data and to compare it with that calculated by allometric scaling.

Methods: Eight clinically normal female Bilgorajska geese were used in a three-phase study with a 3-week wash-out period between phases. In the first phase birds received I/V administration of 2?mg/kg MBX; the same dose was given orally in the second and third phases. Blood samples were collected between 0 minutes and 48 hours in the first and second phases, and samples of liver, kidney, lung, muscle and heart were collected following slaughter of birds between 6 and 48 hours in the third phase. Concentrations of MBX in plasma and tissues were analysed using HPLC. Two additional birds served as controls. The optimal dose was calculated based on a minimal inhibitory concentration (MIC) of 0.125 μg?mL using the observed clearance, or using clearance calculated by allometric scaling.

Results: Concentrations of MBX in plasma were detectable up to 24 hours following both I/V and oral administration. Mean oral bioavailability was 26.5 (SD 7.7)%. Concentrations of MBX in all tissues were highest at 6 hours and decreased constantly up to 34 hours. The mean optimal daily dose for oral administration of MBX, calculated using the observed clearance was 10.36 (SD 2.18) mg/kg, and using predicted clearance was 5.54 (SD 0.14) mg/kg. The preliminary withdrawal time for a maximum residue limit of 0.15?mg/kg calculated for muscle was 38.4 hours, heart 33.6 hours, kidney 48.3 hours, lung 47.7 hours and liver 49.3 hours.

Conclusion and Clinical Relevance: There was insufficient evidence to recommend MBX orally administered to geese at a daily dose of 2?mg?kg for treatment of bacteria with an MIC of 0.125?μg/mL. Further pharmacokinetic/pharmacodynamic studies in geese are recommended to determine the MBX dose regimen and its clinical efficacy in geese.     

Development of refining and petrochemical industries in East Asia: An interpretation based on the Flying Geese Paradigm

Several East Asian countries, with scarcely any crude oil, have developed since the second half of the twentieth century strong production capacities in refining and petrochemicals. This has been the case in Japan, Taiwan, Singapore, South Korea, Malaysia, Thailand, Indonesia and China. This paper assesses whether the development of refining and petrochemical industries in these countries may be better understood with the aid of one of the major interpretative paradigms of structural change and foreign relations in East Asia: the Flying Geese Paradigm. The article concludes that, overall, the production and external relations in oil‐related industries do indeed follow a Flying Geese Paradigm pattern. We observe, nevertheless, some dissonances that are attributable to the particularities of intermediate sectors (such as refining and basic petrochemistry).     

日粮苏氨酸水平对0-8周龄鹅生长性能及屠宰性能的影响

[目的]确定0～8周龄扬州鹅适宜的日粮苏氨酸水平。[方法]在单因素试验中,选用体重相近的1日龄扬州鹅雏鹅300只,公母各半。随机分成5个处理组,苏氨酸设5个梯度水平,分别为0．54％（基础日粮组）、0．64％、0．74％、0．84％和0．94％,研究了日粮苏氨酸水平对0～8周龄鹅生长性能和屠宰性能的影响。[结果]日粮苏氨酸水平极显著影响了0～4周龄仔鹅的体重（P〈0．01）,显著影响了0～4周龄仔鹕的饲料转化比（P〈0．05）,但对5-8周龄鹅体重和饲料转化比的影响不显著。苏氨酸水平对8周龄鹅屠宰性能的影响不显著,8周龄鹅的全净膛率、胸肌率和腹脂率在苏氨酸水平为0．74％时达到最大值,腿肌率则在0．84％时达到最高。[结论]综合0～8周龄鹅的生长性能和屠宰性能各指标,建议日粮苏氨酸水平为0．74％～0．84％.