安徽省北部地区猪高热病流行病学调查

2008年7月,安徽省北部地区生猪出现疫病,表现为不食、高热等特征,为查明病因,进行流行病学调查,同时采集发病猪群样品进行病原学和血清学检测。结果137份血清样品中,HPRRSV、PRRSV、PPV带毒率分别为25.5%、23.4%、37.9%;PRRSV、SIV(H1N1、H3N2)抗体阳性率分别为86.5%、9.49%和3.65%,仔猪CSFV抗体免疫合格率为50%;6份组织样品中HPRRSV、PRRSV、CSFV、PRV、PPV带毒率分别为50%、100%、66.7%、33.3%、33.3%。表明引起本次猪病为PRRSV、CSFV、PPV等多种病原体混合感染。     

奶牛蹄病的治疗

将患有蹄病的牛按病情严重程度分三级,在每级中各选出12头,并将36头随机分成4组,每组共9头。第1组为对照组,第2组每头牛日粮中加35%石粉18g,第3组每头牛日粮中加硫酸锌1.2g,第4组每头牛日粮中同时加35%石粉18g和硫酸锌1.2g。同样护理,每星期对试验牛群进行修蹄及常规治疗。经过1个月的治疗第1组治愈1头,有效3头,无效5头;第2组治愈2头,有效6头,无效1头;第3组治愈3头,有效4头,无效2头;第4组治愈7头,有效2头,无效0头。卡方检测除第2、3两组差异不显著外,其他各组之间差异显著。说明在日粮中适量提高钙和锌对奶牛蹄病有良好的预防和治疗作用。     

Two Akabane virus glycoprotein Gc domains induce neutralizing antibodies in mice

Akabane virus (AKAV), belonging to the genus Orthobunyavirus and family Peribunyaviridae, causes reproductive and congenital abnormalities in ruminants. Its envelope glycoprotein Gc is a neutralizing antigen, on which at least five distinct antigenic regions have been identified. We attempted to identify the domains using truncated recombinant AKAV Gc proteins expressed in Escherichia coli and monoclonal antibodies (mAbs) with AKAV-neutralizing activity. Dot blot analysis revealed that amino acid positions 1–97 and 189–397 (Gc_1–97 and Gc_189–397) in the truncated recombinant proteins reacted with the mAbs. Additionally, AKAV was neutralized by sera from mice immunized with these recombinant proteins. The results suggested that the two domains contain neutralizing epitopes and could be potential subunit vaccines against AKAV.     

Endogenous hydrogen sulfide regulates oxidant/antioxidant balance in rat with chronic obstructive pulmonary disease

AIM: To investigate the role of hydrogen sulfide (H₂S) in the protection against oxidative stress in rats with chronic obstructive pulmonary disease (COPD).METHODS: The rat model of COPD was established by cigarette smoking (CS) combined with lipopolysaccharide (LPS) instillation. Thirty-two healthy male Sprague-Dawley rats were randomly divided into 4 groups: control group, CS+LPS group, CS+LPS+NaHS (H₂S donor) group and CS+LPS+PPG (DL-propargylglycine, an inhibitor of cystathionine-γ-lyase) group. After 30 days, the lung functions of the rats were measured, the histological changes of lungs were observed under light microscope and the pathological scores were calculated. The H₂S level in plasma and the protein expression of cystathionine-γ-lyase (CSE) in the lung tissues were measured. The content of malondialdehyde (MDA), the activity of superoxide dismutase (SOD) and catalase (CAT) were detected to reflect oxidative stress.RESULTS: Compared with control group, the peak expiratory flow (PEF) decreased by 24% and intra-pressure (IP) increased by 66% in CS+LPS group. The pathological scores of the lung tissues also increased. Compared with CS+LPS group, no change in the lung function was observed after given NaHS or PPG, but the pathological scores decreased in CS+ LPS+ NaHS group. Compared with control group, the content of H₂S in plasma was increased by 26% on day 16. Compared with CS+LPS group, the content of H₂S in plasma of CS+LPS+PPG group was decreased by 22% after 30 days. Compared with control group, the protein expression of CSE increased, and no statistical difference among CS+LPS group, CS+ LPS+ NaHS group and CS+LPS+PPG group was observed. Compared with control group, MDA content in the lung tissues was increased by 24% in CS+LPS group, the activity of SOD was increased by 47% and the activity of CAT was increased by 52%. Compared with CS+LPS group, the MDA content in CS+LPS+NaHS group was decreased by 21%, and no statistical difference in the activity of SOD and CAT was observed. The activity of SOD decreased by 33% after given PPG.CONCLUSION: H₂S plays a role as anti-oxidant in the rats with COPD. The CSE/ H₂S pathway may be involved in the development of COPD.     

猪脐静脉血管内皮细胞的分离及体外培养研究

为建立一种操作简单并且能获得大量猪血管内皮细胞的分离培养方法,本研究采集新生健康长白猪脐带,取其脐静脉血管,灌注0.1%的Ⅰ型胶原酶,于37℃水浴消化10 min后收集内皮细胞,培养于含20%胎牛血清的M199培养基中,长满单层后用胰酶消化传代培养。并对培养的细胞形态学、相关抗原和其他特征以及对病毒的易感性进行鉴定。结果表明,Ⅰ型胶原酶消化后可获得大量内皮细胞,细胞培养后的形态学观察显示细胞贴壁生长良好,呈典型的铺路石状排列;第Ⅷ因子相关抗原和细胞摄取乙酰化低密度脂蛋白均呈阳性,内皮细胞比率可高达100%。传3代后的生长曲线显示细胞传代后延迟期小于1 d,对数生长期约3 d,第5 d进入平台期,第7 d开始脱落死亡。病毒感染试验表明所获得的内皮细胞对猪瘟病毒高度易感,病毒生长与常用的PK-15没有区别。上述研究结果表明本研究建立的血管内皮细胞分离培养方法简便有效,为大量制备原代血管内皮细胞提供了可靠的方法。     

禽白血病病毒J亚群诱导蛋鸡群多种肿瘤

2009年8月,山东泰安某海兰褐商品蛋鸡场,开产后产蛋率只有60％～70％,31周龄时,死亡率突然增加,最高达20％.患病鸡经大体剖检、病理组织学、PCR和免疫组织化学检测确诊为J亚群禽白血病.病理组织学检测发现送检鸡除了髓细胞瘤外,还存在明显的纤维肉瘤、组织肉瘤、腺癌和血管内皮瘤等肿瘤.纤维肉瘤单独存在,组织肉瘤、腺癌和血管内皮瘤分别和髓细胞瘤混合存在,本文详细描述了各肿瘤的组织学特点.ALV-J从肉种鸡传向商品蛋鸡后引起肿瘤谱扩展的原因和机制值得进一步研究.     

犬瘟热病毒N蛋白基因融合蛋白原核表达条件的优化与蛋白纯化

[目的]提高犬瘟热病毒N蛋白基因在大肠杆菌中表达可溶性GST融合蛋白的含量.[方法]研究诱导剂(IPTG)的最佳加入时间、诱导剂(IPTG)浓度、诱导时间以及不同温度条件对GST - CDV N融合蛋白表达的影响,获得在大肠杆菌中的最佳的表达条件,然后再在最佳条件下大量的表达,用GST - Sepharose 4B亲和层析柱对GST - CDV N融合蛋白进行纯化,得到最大量的可溶性融合蛋白,并对蛋白含量进行测定.[结果]大肠杆菌BL21 (DE3)转化菌在37℃培养3.5 h(OD600 =1.314)时,加入IPTG使终浓度为1 mmol/L,然后在27℃诱导8h,GST - CDV N融合蛋白可溶性表达量最高,达到0.862 mg/mL.[结论]确定了犬瘟热病毒N蛋白基因的优化表达条件,为犬瘟热病毒分子免疫学诊断和亚单位疫苗的研制奠定了基础.