猪瘟病毒和猪圆环病毒2型引起猪免疫抑制的研究进展

猪瘟病毒和猪圆环病毒2型主要侵害猪的免疫系统,使机体免疫力降低,给养猪业带来巨大的经济损失,目前对该病尚无有效治疗方案,疫苗免疫仍是主要的防控途径。因此,开展猪瘟病毒和猪圆环病毒2型的免疫学致病机制研究具有十分重要的意义。论文综述了猪瘟病毒和猪圆环病毒2型通过引起免疫细胞数量减少、免疫细胞和器官损伤、免疫相关因子和细胞因子表达失衡以及免疫检查点分子过表达等方面造成机体淋巴细胞衰竭和免疫抑制的相关研究进展,为猪瘟病毒和猪圆环病毒2型的科学防控提供理论依据。

具核梭杆菌促进结直肠癌发生机理的研究进展

结直肠癌(CRC)是全球第三大流行癌症,对人类的健康危害很大。大量研究证明,结直肠局部微生态改变与CRC的发生有关。通过宏基因组学及高通量测序技术运用,发现CRC患者的肿瘤微生态环境和粪便样本富集了大量具核梭杆菌。因此,具核梭杆菌被认为是CRC发生、发展的危险因素之一。迄今为止,具核梭杆菌引起CRC的发生机理还不清楚。论文从具核梭杆菌对大肠及CRC组织固有免疫细胞的抑制作用、具核梭杆菌特异性毒性因子对CRC发生的影响、具核梭杆菌的促癌性miRNA形成和具核梭杆菌促炎性因子对CRC细胞的影响等几个方面阐述了具核梭杆菌引起CRC的发生机理。

Ultrastructure Observation of Cysticercus Pisiformis and Its Function Analysis

[ Objective] The aim of the study was to observe the ultrastructure of Cysticercus pisiformis under different state. [ Method] The Cysti- cercus pisiformis were obtained in the procedure of slaughter inspection form meat-packing plant. The Cysticercus pisiformis was taken out by cut- ting cyst directly, or cultured with physiologic saline containing 10% bile until evagination. Then it was observed and recorded by scanning electron microscopy. [ Result] Observed from top of scolex of Cysticercus pisiformis locate in cyst, the rostellum looked like an umbrella. The cutaneous muscular columns with hamula covered the front end of scolex. Viewed from the side, a row of antlers-liking hamula adhered to the scolex. Four suckers were looked like more width and body segments less time, in which there were lots of wrinkles in their surface respectively. The Cysticercus pisiformis cultured was divided obviously into scolex, neck, body segment and zone of cyst. When cutaneous muscular column of rostellum con- tracted, the antler-liking hamula extended to periphery that the ring-liking contraction appeared in neck and the lengthways contraction in body seg- ments. [ Conclusion] The Cysticercus pisiformis under different state has distinctly dissimilar ultrastructure.

Pathogenesis of Demyelinating Encephalopathy in Dogs with Spontaneous Acute Canine Distemper

So far, the pathogenesis of demyelination caused by canine distemper virus （CDV） in the central nervous system has remained unclear, although a lot of studies have been done extensively. To further investigate the relation of variety cells in brain to demyelination, this study was performed on 15 dogs with spontaneous acute canine distemper and 2 controls. According to anatomical relation, the brain was divided into cerebrum, cerebral stem and cerebellum. The sections with no, mild, moderate, or severe demyelinating lesions were selected respectively and stained by HE and immunohistochemistry. Immuno-localisation of CDV antigen was used to conftrm CDV infection. The brain was examined for co-localisation of the CDV antigen with either an astrocyte-specific marker, glial fibrillary acidic protein （GFAP）, or an oligodendrocyte-specific marker, galactocerebroside （GalC）. Apoptotic cell was detected by TdT-mediated nick end-labeling assay （TUNEL）. The results demonstrated that the local disturbance of blood circulation mainly included congestion, edema, thrombosis, and disseminated intravascular coagulation （DIC）. The CDV neucleocapsid protein positive reaction, metabolic disorder and apoptosis of oligodendrocytes were observed in demyelinating areas. Lots of astrocytes displayed CDV antigen-positive, especially in their process. Some of them became apoptotic cell confirmed by TUNEL staining. Fibrous astrocytes showed more intense GFAP-positive in mild and moderate demyelinating area. Some of nervous cells located in pyramidal cell layers and nucleus nervi were in degeneration, necrosis. Satellitosis, neuronophagia and apoptotic neurons were examined by hematoxylin and eosin （HE） and TUNEL staining. The results suggested that the demyelinating changes in brain tissues infected with CDV mainly related to the metabolic disorder and apoptosis of ogliodendrocytes and astrocytes; also involved with the local disturbance of blood circulation and some neuron lost.

诊断兔豆状囊尾蚴病的阻断ELISA方法的建立和初步应用

为了提高对兔豆状囊尾蚴病的血清学诊断率,本研究用纯化的63 000囊液蛋白免疫BALB/c小鼠,获得了高效价一抗,再用63 000囊液蛋白作为包被抗原,以辣根过氧化物酶（HRP）标记的山羊抗鼠IgG为二抗,通过对各种试验条件的优化,建立了特异诊断兔豆状囊尾蚴病的阻断ELISA方法。结果显示,63 000囊液蛋白最佳包被浓度是5mg/L;一抗最佳稀释度为1∶800;最佳封闭时间是37℃3h;二抗最佳稀释度为1∶5 000,最佳反应时间是37℃30min;底物显色5min,终止反应后可先用目测法进行初步判定,并立即用酶标仪检测,根据D450值和判定标准确诊。用新建的阻断ELISA方法对兔的常见病,如兔脑炎原虫病、兔瘟、兔巴氏杆菌病、兔球虫病和弓形虫病进行了检测,均无交叉反应。从屠宰场和感染兔场随机采集150份血清样品,分别用阻断ELISA方法和间接血凝试验（IHA）进行比较检测,证明阻断ELISA方法的诊断率明显高于IHA。总之,阻断ELISA方法是一种简便、快速、灵敏和准确诊断兔豆状囊尾蚴病的新方法,适宜于基层兽医工作者应用和推广。

阿苯达唑和吡喹酮对兔豆状囊尾蚴病疗效的比较

为研究阿苯达唑和吡喹酮对兔豆状囊尾蚴病的治疗效果,将30只患豆状囊尾蚴的病兔随机分为3组,分别用阿苯达唑、吡喹酮和淀粉进行2个疗程的治疗,从临床症状、体质量变化、白细胞分类变化、病理学宏观、微观和超微结构检查等方面进行比较观察。结果证明2种药物对兔豆状囊尾蚴病的治疗主要有3点不同:一是阿苯达唑可使豆状囊尾蚴头节的齿钩破坏,吸盘闭锁,并发生凝固性坏死和钙化,囊液充分吸收;而吡喹酮主要引起头节和原始体节起泡、破溃和崩解,皮层破坏,平滑肌收缩,吸盘口闭合,死亡的虫体呈扭曲状,囊液吸收不充分。二是阿苯达唑可引起嗜酸性粒细胞增多,但反应较慢;吡喹酮能在较短的时间内引起嗜酸性粒细胞明显增多。三是阿苯达唑治疗组的增长速度比吡喹酮治疗组的快,差异显著,而2治疗组的增长速度均比对照组的快,差异非常显著。总之,阿苯达唑和吡喹酮对兔豆状囊尾蚴病均有较好的疗效,但以前者更好。

兔脑炎原虫引起的脑组织细胞凋亡

为了调查兔脑炎原虫引起脑组织细胞的凋亡情况,本研究用特殊染色、TUNEL染色、凋亡蛋白免疫组化染色和Western blot,对40只家兔的脑组织进行了详细研究。结果表明,病兔的脑组织中均检出了肉芽肿和脑炎原虫。脑炎原虫所引起的脑细胞凋亡主要发生于脑血管的内皮细胞、星形胶质细胞、巨噬细胞和上皮样细胞,其次为病变所累及的神经细胞。用TUNEL的免疫酶-荧光染色和抗凋亡蛋白的免疫组化染色,凋亡细胞均呈强阳性反应,被染成棕褐色。对脑组织蛋白提取物进行Western blot检测,病兔脑组织中P^(53)、Bcl-2、Bax和c-Myc凋亡基因蛋白表达量明显高于对照兔,差异非常显著(P<0.01)。结果表明,兔脑炎原虫在脑组织细胞内寄生时可以引起细胞凋亡。

兔脑炎原虫致脑细胞凋亡的信号转导通路的研究

为探讨兔脑炎原虫引起脑组织细胞凋亡的信号转导通路,本试验用普通染色、特殊染色、免疫组化染色和Western blot检测等方法,对40只病兔和10只对照兔的脑组织进行了研究。结果显示,病兔的脑组织中均检出了形态不一的肉芽肿和脑炎原虫。兔脑炎原虫可引起巨噬细胞和肉芽肿中的上皮样细胞表达TNF-α,anti-TNF-α抗体染色呈阳性反应。细胞凋亡信号转导通路的关键蛋白caspase-8和caspase-3在血管内皮细胞、星形胶质细胞和上皮样细胞中呈强阳性或阳性反应,被anti-caspase-8和anti-caspase-3抗体染成淡棕色或深棕色。对脑组织蛋白提取物进行Western blot检测,病兔脑组织中TNF-α,caspase-8和caspase-3的表达量明显高于对照兔,差异极显著(P<0.01)。结果表明,兔脑炎原虫可刺激脑组织中的巨噬细胞和上皮样细胞产生大量TNF-α,后者与细胞膜上的TNFR结合,从而激活死亡受体通路,引起胞浆内的caspase家族发生级联反应,导致细胞凋亡。