水温升高对黑斑侧褶蛙蝌蚪变态时长和血液参数的影响

为探究升温对黑斑侧褶蛙（Pelophylax nigromaculatus）变态时长、形态表型和血液参数的影响,在水温为21、23、25和27℃条件下,测定了从37期蝌蚪发育至46期变态完成期时的变态时长、身体大小、血液中各型白细胞的百分比及嗜中性粒细胞与淋巴细胞的比值（N/L的比值）的变化。结果显示,21 ℃组和23 ℃组的变态时长显著长于25 ℃组和27 ℃组（P < 0.05）;体重、体长以及体重与体长的比值都在21 ℃组最高,25 ℃组最低,但均无明显的组间差异（P > 0.05）。水温对血液淋巴细胞、嗜中性粒细胞、嗜酸性粒细胞、嗜碱性粒细胞和单核细胞的百分比以及N/L的比值均无明显影响（P > 0.05）。升温可加速黑斑侧褶蛙蝌蚪的变态过程,但不影响各型白细胞所代表的天然免疫能力和应激反应能力。     

Influenza A Viruses Detected in Swine in Southern Germany after the H1N1 Pandemic in 2009

Infections with influenza A viruses (IAV) are highly prevalent in swine populations, and stable cocirculation of at least three lineages has been well documented in European swine – till 2009. However, since the emergence of the human pandemic pdmH1N1 virus in 2009, which has been (re)introduced into individual swine herds worldwide, the situation has been changing. These variations in the respective IAV pools within pig populations are of major interest, and the zoonotic potential of putative emerging viruses needs to be evaluated. As data on recent IAV in swine from southern Germany were relatively sparse, the purpose of this study was to determine the major IAV subtypes actually present in this region. To this aim, from 2010 to 2013, 1417 nasal swabs or lung tissue samples from pigs with respiratory disease were screened for IAV genomes. Overall, in 130 holdings IAV genomes were detected by real‐time RT‐PCR targeting the matrix protein gene. For further analyses, several PCR protocols were adapted to quickly subtype between H1, pdmH1, H3, N1 and N2 sequences. Taken together, cocirculation of the three stable European lineages of IAV was confirmed for Bavaria. H1N1 sequences were identified in 59, whereas H1N2 genomes were only diagnosed in 14, and H3N2 in 9 of the holdings analysed. However, pdmH1 in combination with N1 was detected in 2010, 2012 and 2013 confirming a presence, albeit in low prevalence, likewise pdmH1N2 reassortant viruses. Interestingly, individual cases of coinfections with more than one subtype were diagnosed. Partial genome sequences were determined and phylogenetic analyses performed. Clearly other than in the human population classically circulating IAV have not been displaced by pdmH1N1 in Bavarian swine. However, some interesting viruses were detected. Further surveillance of these viruses in the Bavarian pig population will be of major importance, to monitor future developments.     

动物中几种主要谷胱甘肽S-转移酶亚型的研究进展

谷胱甘肽s-转移酶是生物体内一类重要的解毒酶,主要在抗毒机制第Ⅱ阶段起作用,在许多脊椎动物和无脊椎动物中参与免疫防御和代谢过程,已作为生物标记基因而广泛用于环境污染评估。本文阐述了胞质中几种主要谷胱甘肽s-转移酶亚型的生物学性质和作用,及其国内外研究的最新进展,以期为进一步开发谷胱甘肽s-转移酶提供指导。     

2株H9N2流感病毒的分离及HA基因序列分析

为掌握近年来H9亚型禽流感的流行状况和遗传变异规律,从河南、陕西发病养殖场采集病料,用鸡胚接种法分离病毒,并用RT-PCR法对分离出的H9N2AIV的HA基因进行扩增、克隆、测序及对得到的序列进行同源性和遗传性分析。结果表明:获得了2株H9N2亚型流感病毒,这2株病毒HA基因变异程度不大,核苷酸序列和氨基酸同源性分别为97.1%和97.8%,均属于BJ/1/94分支(Y280小分支)。从分子水平分析,这2株病毒均属于低致病力的H9N2禽源流感病毒。     

我国财产保险保费收入影响因素的实证研究

财产保险保费收入是衡量财产保险发展水平的一个重要依据。从财产保险的险种构成出发,使用固定个体效应回归模型,以2007—2012年我国31个省、直辖市的财产保险保费收入为面板数据,找出反映财产保险的主要险种分别对我国财产保险保费收入的影响,最终得出财产保险保费收入与其影响因素之间的回归方程和经济含义。因此,该研究结果有助于更有针对性地采取相应的措施解决现有问题,提升我国财产保险业的广度和深度;同时也为我国的保险公司制定战略和改进特定业务提供方向,为政府制定有关财产保险行业的政策提供依据,最终促进宏观经济的增长。     

Phylogenetic analyses and molecular epidemiology of European salmonid alphaviruses (SAV) based on partial E2 and nsP3 gene nucleotide sequences

Sequence data were generated for portions of the E2 and nsP3 genes of 48 salmonid alphaviruses from farmed Atlantic salmon (AS), Salmo salar L., and rainbow trout (RT), Oncorhynchus mykiss (Walbaum), in marine and freshwater environments, respectively, from the Republic of Ireland, Northern Ireland, England, Scotland, Norway, France, Italy and Spain between 1991 and 2007. Based on these sequences, and those of six previously published reference strains, phylogenetic trees were constructed using the parsimony method. Trees generated with both gene segments were similar. Clades corresponding to the three previously recognized subtypes were generated and in addition, two further new clades of viruses were identified. A single further strain (F96-1045) was found to be distinct from all of the other strains in the study. The percentage of nucleotide divergence within clades was generally low (0-4.8% for E2, 0-6.6% for nsP3). Interclade divergence tended to be higher (3.4-19.7% for E2, 6.5-28.1% for nsP3). Based on these results and using current SAV terminology, the two new clades and F96-1045 were termed SAV subtypes 4, 5 and 6, respectively. SAV4 contained AS strains from Ireland and Scotland, while SAV5 contained only Scottish AS strains. Recently identified SAV strains from RT in Italy and Spain were shown to belong to SAV2. In addition, marine AS strains belonging to SAV2 were identified for the first time. Analysis of the origin of several clusters of strains with identical E2 and nsP3 sequences strongly support horizontal transmission of virus between farms and aquaculture companies. Evidence in support of vertical transmission was not found.     

H5-H7双价禽流感核酸疫苗免疫研究

由于禽流感的高度变异性,免疫后不同亚型之间难以得到交叉保护,以致病毒得以逃避宿主免疫系统的监视,多价核酸禽流感疫苗具有可以保护不同亚型病毒攻击的特点。本试验设计并构建了包含禽流感H5HA和H7HA1基因的双价真核表达质粒pV-H5-H7及单独表达H5HA和H7HA1的pV-H5和pV-H7HA1。通过RT-PCR,间接免疫荧光(IFA)等方法验证构建质粒的正确性和其表达蛋白的免疫原性。0,21 d分别免疫6~8周龄的BALB/c小鼠,设立双价疫苗组,单表达免疫组和对照组。免疫后35 d用HPAIV H5N1进行致死性攻击。结果显示免疫组均可刺激机体产生H5特异性抗体,pV-H5-H7诱导产生的抗体对H5N1的攻毒保护率为80%,而pV-H5单表达的攻毒保护率也为80%。表明本实验构建的双价禽流感核酸疫苗的免疫效果与单表达组相当(P>0.05),为多价禽流感核酸疫苗的研制提供了基础。     

贵阳市鸡群中禽流感不同亚型抗体的检测与分析

禽流感是由A型流感病毒引起禽类的一种烈性传染病,被世界动物卫生组织及国家农业部列为一类或A类动物疫病。根据A型流感病毒的血凝素（HA）和神经氨酸酶（NA）抗原性的差异,可将A型流感病毒分为不同的亚型。禽流感病毒属于A型,不同毒株的致病性存在差异,根据其对禽类致病力的不同,又可划分为高致病性毒株、低致病性毒株和非致病性毒株。     

禽流感H5、H9亚型灭活油乳剂疫苗的免疫效果评价

对采自成都市牧星蛋鸡场免疫鸡群的2943份血清样品进行了H5、H9亚型禽流感抗体免疫接种试验。结果表明,在2943份血清样品中,tt5、H9亚型HI效价≥410g2的样品数量分别为2455、2738份,免疫合格率分别为83-4％、93．1％,免疫后抗体高峰维持7log2以上的时间达63d以上。超过蛋鸡场免疫合格标准,可...     

Pathozones of genetic subtypes of Gaeumannomyces graminis in cereals

The extent of damage to the host plant caused by Gaeumannomyces graminis var. tritici (Ggt) and var. graminis (Ggg) is a result of a net effect of host susceptibility and mycelium infectivity. The disease severity on cereal roots caused by G. graminis (Gg) fungi varies considerably depending on the genetic subtypes. Results of our rhizobox placement experiments additionally showed a subtype-specific effect of the spatial distance between host and fungus on the infection. The highest pathogenicity of each subtype was found in different zones of the root system: pathozones of different subtypes alternated along the root. The extent of the pathozone profiles did not depend on the infectivity of the inoculum and plant age. However, disease severity was shown to be affected by defence reactions of the host plant. An attack of a fungal subtype that is easily recognized by the host plant leads to defence reactions like increased root growth, thus minimizing the damage to the shoot. Detailed analysis showed that a Ggt subtype had a high potential for colonizing root laterals. It formed concentric zones of high colonization efficiency at a distance of ca. 5 cm around the shoot.