Expression kinetics of chicken β2-microglobulin and Class I MHC in vitro and in vivo during Marek’s disease viral infections

Marek’s disease virus (MDV) is a highly cell-associated herpesvirus that causes a disease in chickens characterized by tumor formation and immunosuppression. The changes of major histocompatibility complex (MHC) expression in different MDV-infected cells are not completely understood. In this study, we investigated the expression of the Class I MHC and β2-microglobulin (β2m) genes in response to MDV infection at different time points by real-time PCR. In both in vitro and in vivo, the expression levels of Class I MHC and β2m genes were upregulated during early MDV infections in comparison to control cells; We also found that the expression of Class I MHC gene was downregulated in BudR (5-bromo-2′-deoxyuridine)-treated MSB1 cells at 48 h and MDV-infected chicken embryo fibroblast cells (CEF) at 120 and 168 h post infection (hpi); Furthermore, compared to control groups, Class I MHC and β2m expression levels were downregulated in peripheral blood lymphocytes (PBLC) from MDV-infected chickens at 14 and 28 days post infection (dpi); Interestingly, both Class I MHC and β2m gene expression levels increased again in PBLC from MDV RB1B-infected chickens at 35 dpi, in which MDV was in the latent or transformed infection stages. In addition, Class I MHC expression was clearly decreased in MDV-infected CEF at 120 hpi although β2m expression was significantly increased. These changes in Class I MHC and β2m gene expression might provide more insights into host-virus interaction.     

鸡黄病毒灭活疫苗的研制及免疫效果研究

鸡黄病毒FQ—C1株经SPF鸡胚连续传40代后,检测其尿囊液毒的ELD50达到1×10^-4.33／0．1mL。将该病毒第40代SPF鸡胚液毒灭活后制备成油乳剂灭活疫苗。SPF雏鸡和蛋鸡安全性试验表明,该疫苗的安全性好,无不良影响。以该疫苗一次单剂量（1mI／只）免疫开产蛋鸡,28d后攻以鸡黄病毒强毒测定疫苗的保护效果,结果显示疫苗免疫组较未免疫组蛋鸡的产蛋率高出75．8％,产蛋保护率达93．2％以上。试验表明,本研究制备的鸡黄病毒灭活疫苗安全性好,且具有良好的免疫原性,免疫后可有效抵抗鸡黄病毒所致的产蛋骤降。     

Genomic sequence and cardiac expression of atrial natriuretic peptide in cats

OBJECTIVE: To determine the nucleotide and amino acid sequence of atrial natriuretic peptide (ANP) in cats and its typical regions of cardiac expression. ANIMALS: 5 healthy adult mixed-breed cats. PROCEDURE: Total RNA was extracted from samples obtained from the left and right atrium, left and right ventricle, and interventricular septum of each cat. The RNA was used to produce cDNA for sequencing and northern blot analysis. Genomic DNA was extracted from feline blood samples. Polymerase chain reaction primers designed from consensus sequences of other species were used to clone and sequence the feline ANP gene. RESULTS: The feline ANP gene consists of 1,072 nucleotides. It consists of 3 exons (123, 327, and 12 nucleotides) separated by 2 introns (101 and 509 nucleotides). It has several typical features of eukaryotic genes and a putative steroid-response element located within the second intron. Preprohormone ANP consists of 153 amino acids. The amino acid sequence of the active form of feline ANP (ANP-30) is identical to that of equine, bovine, and ovine ANP-30 and differs from that of human, canine, and porcine ANP-28 only by 2 carboxy-terminal arginine residues. The ANP mRNA was detected only in the left and right atria. CONCLUSIONS AND CLINICAL RELEVANCE: The genetic and protein structure and principal regions of cardiac expression of feline ANP are similar to those of other species. Results of this study should be helpful in future studies on the natriuretic response in cats to diseases that affect cardiovascular function.     

山羊毛霉菌病临床与病理学观察

以１０７个／ｍｌ微小根毛霉（Ｒｈｉｚｏｍｕｃｏｒｐｕｓｉｌｕｓ）孢囊孢子悬液颈静脉接种２月龄山羊,每只５ｍｌ,每日１次,连续３日,经８８ｄ观察３／４只山羊死亡。病羊临床表现精神沉郁,消瘦,体温升高,腹泻,后肢瘫痪,白细胞总数及嗜中性白细胞成倍增加,全血ＧＳＨ－ＰＸ活性降低,Ｓ－ＧＯＴ、Ｓ－ＧＰＴ和ＡＫＰ活性升高,血清胆固醇值上升,但以上各项血液生化指标变化与对照羊相比差异不显著（ｐ＞０．０５）。病理变化为全身扩散性毛霉菌病,其典型病变在肺脏,整个肺脏遍布灰白色圆形小结节。镜险肺结节中心为毛霉菌丝或碎片,周围淋巴细胞、单核细胞包绕。腿肌大部分肌束呈凝固性坏死,周围微血管内形成血栓     

我国气候因素的变化对奶牛生产的影响

在分析我国气候因素变化的基础上,着重阐述了气候因子对我国奶牛采食,饲料利用率,产奶量和乳成分,奶牛的繁殖力,日增重及发病率等生产性能的影响。结果表明,高温高湿是奶牛生产的主要环境因子。作者不提出了控制奶牛环境的若干措施。     

鸡霍乱流行病学研究

禽霍乱病原菌肌肉注射人工感染成年鸡后,禽霍乱病原菌首先局限于注射部位生长繁殖,其他部位不能检出菌,静脉注射禽霍乱病原菌入血后,血中含菌数很快就迅速下降,出现一个低谷期,然后才不断上升。各组织、器官在任一时刻的含菌数各不相同,肝、脾含菌量最高。在血中可测到禽霍乱病原菌数量增加时,所感染的鸡均出现临床症状,并在几小时后死亡。分析认为,在各好嗜性组织器官中禽霍乱菌的大量繁殖是导致病鸡死亡的关键因素。     

湖南省动物疫情测报站的作用与管理

湖南省根据地理区域和养殖业结构情况,合理布局建立了18个省级动物疫情测报站,通过对测报站辖区内及定点养殖场户的生产、免疫、疫病等情况进行持续跟踪调查和监测采样,评估动物群体免疫状态及疫情发生风险。管理上通过优化网络布局,提高诊断监测能力,通过强化培训和责任管理,提升动物疫情测报水平,确保了动物疫情测报质量。动物疫情测报站在发现新发重大动物疫病,评价强制免疫病种免疫效果,提供疫情预警预报基础数据以及指导养殖业生产等方面发挥了重要作用。今后需持续增加投入和监测科技含量,改善设施设备,稳定技术队伍,这是提高动物疫情测报监测的根本保障。     

Teratogenic effects of chronic ingestion of high levels of vitamin A in cats

High concentrations of retinoids occur in some commercial cat food formulations as a result of the use of animal liver as an ingredient. Our objective was to study the teratogenic potential of dietary vitamin A in cats. We investigated the incidence of birth defects in kittens of queens given diets with retinyl acetate concentrations of 6000, 306000, or 606000 retinol equivalents (RE)/kg diet (control, 306K, or 606K groups, respectively) for approximately 3 years [1 RE=1 micro g retinol=3.3 International Units (IU)]. Each group comprised 12-15 age-matched, nulliparous domestic short-haired queens that were exposed to toms. There were a total of 396 kittens born in 97 litters. Pregnancy rate, number of kittens per gestation and gestations per year were not significantly different among treatment groups. A total of 2, 5 and 11 malformed kittens occurred in the control, 306K and 606K groups, respectively. Malformations included cleft palate, cranioschisis, foreshortened mandible, stenotic colon, enlarged heart and agenesis of the spinal cord and small intestine, which are typical foetal defects consistent with ingestion of excess retinoids in other species. This study demonstrated that a concentration of 306000 RE/kg diet has a potential for causing birth defects in the kittens.     

增蛋散对蛋鸡内分泌及消化作用的影响

将768只421日龄海兰白蛋鸡随机均分为2组,分别饲喂添加0和1.5%中药增蛋散的2种饲料,于饲养30、60d时采血和屠宰,测定血样中卵泡刺激素(FSH)、促黄体素(LH)、三碘甲状腺原氨酸(T3)、甲状腺素(T4)、雌二醇(E2)、孕酮(P4)、甲状旁腺素(PTH)、环磷酸腺苷(cAMP)等的含量及饲料中粗蛋白和钙的消化率,探讨该散剂促产蛋的作用机制.结果显示,当日粮中添加增蛋散饲喂30、60 d时,蛋鸡血清中FSH、LH、T3、T4、E2、P4、PTH的含量,下丘脑和腺垂体中cAMP含量及饲料中粗蛋白和钙的消化率均有显著提高(P＜0.05或P＜0.01).本试验结果为该散剂提高产蛋后期鸡的产蛋率,推迟其淘汰期的药理作用提供了实验依据.     

以CP23重组蛋白为抗原建立检测微小隐孢子虫抗体间接ELISA方法的研究

摘要：以在E.coli高效表达的微小隐孢子虫子孢子表面抗原CP23为抗原，以辣根过氧化物酶(HRP)标记的山羊抗鼠IgG为二抗，建立了检测微小隐孢子虫抗体的间接ELISA方法。经检测筛选出最佳反应条件为1μg／孔纯化的E.coli表达的CP23抗原包被酶标板，用10％免血清进行封闭，以正常E.coli裂解上清液稀释待检血清。实验表明应用CP23重组蛋白作为诊断C.parvum抗原具有特异性高、抗原易纯化和成本低等特点。