伪狂犬病病毒吉林分离株感染BHK-21细胞的超微结构变化

以猪伪狂犬病病毒(PRV)吉林分离株PRV-JL感染体外培养的BHK-21细胞为模型,通过透射电镜对PRV的形态发生学和宿主细胞超微结构的动态变化规律进行研究。结果显示,PRV能导致BHK-21细胞圆缩,并发生细胞融合,形成合胞体;电镜观察到的病毒粒子呈球形或椭圆形,成熟的病毒粒子直径大小为140~210 nm,未成熟病毒粒子直径为90~150 nm,多呈中空状,部分呈致密核芯。病毒吸附于细胞后以膜融合的方式进入细胞,在胞核内复制,装配好的病毒粒子以出芽的方式离开细胞核,获得最初的囊膜,进入胞浆;在胞浆内的病毒粒子又利用高尔基体的膜结构合成第2层囊膜,形成完整的病毒粒子;最后包裹有完整病毒粒子的高尔基囊泡与细胞膜发生融合,将病毒粒子释放到细胞外。感染细胞超微结构变化主要表现为:细胞胞浆空泡增多,内质网扩张,线粒体增生、嵴肿胀、脱落,最后空泡化,整个细胞裂解、破碎。     

牛病毒性腹泻病毒侵染宿主细胞的电镜观察

用电镜观察了牛病毒性腹泻病毒Oregon C24株在侵染新生犊牛睾丸细胞中的形态发生。成熟的病毒颗粒呈直径约为50nm的球形颗粒，内含直径约为30nm的核芯。病毒侵染宿主细胞后，在胞质内复制，通过糙面内质网膜出芽成熟，病毒可通过侵染细胞外排或在细胞死亡后含有病毒颗粒的空泡破溃而释放到胞外。     

欧鳗“狂游症”病原体初步研究

应用电镜超薄切片技术，在患有“狂游症”的欧鳗脑细胞中发现一种弹状病毒，该病毒颗粒只存在于细胞浆中，大小约50－80nm×100-250nm，具有囊膜，囊膜外附有纤突，可造成宿主细胞肿胀和空泡变性等病理变化，它是欧鳗“狂游症”的主要病原体。     

致病性猪伪狂犬病病毒PRV-JF株的分离与鉴定

从临床疑似猪伪狂犬病发病仔猪的脑组织病料中，经聚合酶链式反应（PCR）证实为猪伪狂犬病病毒（PRV）野毒感染，采用无PCV1污染的猪肾细胞系（PK-15）分离培养，经蚀斑克隆纯化，培育1株细胞培养适应毒，命名为PRV-JF株。该分离株经细胞培养传代，能够产生典型的细胞病变，病毒滴度随代次显著增加，第24代毒价达10^8.5 TCID50／mL。免疫过氧化物酶单层细胞试验（IPMA）检测病毒抗原分布在细胞核及细胞质内。病毒感染细胞可被已知PRV阳性血清中和。电镜负染观察到病毒粒子呈椭圆或圆形外观，无囊膜的病毒粒子直径约110nm～150nm，有囊膜的成熟病毒粒子直径约150nm～180nm。PCR鉴定该毒株含有gE基因，其序列与GenBank登录的7株PRV同源性为97.7％～100％。用不同剂量病毒培养物接种家兔于24h～72h内全部死亡。研究表明，PRV-JF分离株对易感动物具有高致病性，为进一步开展该病毒流行病学、致病机理、疫苗免疫与诊断研究奠定了基础。     

从猝死症犬心肌分离出冠状病毒

应用电镜观察，在猝死犬的心肌中发现典型的冠状病毒粒子。用牛肾传代细胞（ＭＤＢＫ）分离培养该病毒获得成功，电镜负染色法跟踪观察，每一代细胞培养液中均观察到典型的冠状病毒粒子。其病毒形态呈圆形和椭圆形为主的多形性，直径７０～１６０ｎｍ，有囊膜，囊膜表面有间距较宽（长约２０ｎｍ）的突起，突起顶端膨大呈鼓槌样，负染色法观察时呈现花冠样结构。用第５代接毒培养的细胞作电镜超薄切片观察，在细胞质的空泡中发现有数量不等的典型冠状病毒粒子，即病毒包涵体。经鉴定为ＲＮＡ病毒，对乙醚敏感，３７℃７２ｈ可失去活性。在ｐＨ３的条件下，３７℃５ｈ仍保持一定活力     

伪狂犬病病毒北京株的纯化及电镜观察

将伪狂犬病病毒（ＰｒＶ）北京株细胞培养物经超速离心沉淀后，用质量分数３０％、３５％、４０％、４５％蔗糖密度梯度离心，收集病毒蛋白带，经１０ｇ／Ｌ醋酸负负染色后电镜观察病毒粒子形态。结果表明，病毒粒子主要集中于３５－４０％蔗糖界面处，有囊膜病毒粒子直径约为１５０－２１０ｎｍ，无囊膜病毒粒子直径约为１００－１６０ｎｍ，证明上述纯化ＰｒＶ的方法是可行的，为今后建立分抗ＰｒＶ杂交瘤细胞株及开展基因工程抗     

猪流行性腹泻的诊断与预防措施

猪流行性腹泻病毒(PEDV)属于冠状病毒科冠状病毒属。病毒粒子呈多边形,倾向球形,直径约95~190 nm,外有囊膜,囊膜上有花瓣状突起,为RNA型病毒。主要探讨了猪流行性腹泻的诊断与预防措施。     

应用离子捕捉电镜技术对兔瘟病毒的检测

兔瘟是一种烈性传染病,目前对此病研究较多,但仍有些问题没有搞清。关于病原问题,我们应用了离子捕捉电镜技术对病兔肝脏、肠内容物进行了检查,结果发现了两种病毒粒子。第一种为无囊膜裸体病毒,直径约为30nm,分空心和实心粒子,其形状呈圆形或六角形;第二种为有囊膜、大小不一、形态不整、并在病毒表面被复有纤突的副粘病毒样粒子。该两种病毒粒子中的第一种粒子的形态结构与多数学者所报道的相同,但第二种粒子还未见有人报道。兔瘟的病原多数学者认为是第一种病毒粒子。     

伪狂犬病病毒的形态发生研究

病毒为圆形或卵圆形,直径为150～170nm,核壳体直径为94～103nm,内部充满致密的核心,在宿主细胞核内,可以观察到特异的毒浆结构和处于不同装配阶段的核壳体,有时在核膜内侧还可以见到被有囊膜的成熟病毒粒子。在细胞质中常常也可以见到装配好的核壳体和成熟病毒,但后者仅存在于细胞质的空泡中,成熟的病毒可能是通过与吞噬作用相反的过程逐渐向细胞外释放。膜增生现象和大量的纤维结构在病变的细胞质中是十分明显的。     

猪繁殖—呼吸综合征病毒的形态学

利用电子显微技术，对从上海某发病猪场分离到3株猪繁殖－呼吸综合征病毒（PRRSV）和标准美洲株（ATCC－VR2332）进行了形态特征的比较。结果表明，这4株病毒形态特征无显著差异。负染显示该病毒以球形为主，具有囊膜，囊膜上有纤突，大小为60－85nm。超薄切片可见病毒粒子大量存在于细胞浆内，有囊膜的直径为60－80nm，没有囊膜的直径为40－50nm，在细胞的线粒体，高尔基体和双基核膜内可见病毒粒子。在病毒增殖的同时，Marc-145细胞的显微结构逐渐发生破损，显示病毒的释放是通过破坏细胞膜结构的完整性来实现的。     

白术、微米白术和白术多糖对断奶仔猪生长性能和肠道形态及微生态区系的影响

试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。     

Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia

Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.     

Y‐chromosomal variation of local goat breeds of Turkey close to the domestication centre

Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.     

Feline intracranial neoplasia: retrospective review of 160 cases (1985-2001)

The purpose of this study was to determine the frequency of different tumor types within a large cohort of cats with intracranial neoplasia and to attempt to correlate signalment, tumor size and location, and survival time for each tumor. Medical records of 160 cats with confirmed intracranial neoplasia evaluated between 1985 and 2001 were reviewed. Parameters evaluated included age, sex, breed, FeLV/FIV status, clinical signs, duration of signs, number of tumors, tumor location(s), imaging results, treatment, survival times, and histopathologic diagnosis. Most of the cats were older (11.3 +/- 3.8 years). Primary tumors accounted for 70.6% of cases. Metastasis and direct extension of secondary tumors accounted for only 5.6 and 3.8% of cases, respectively. Twelve cats (7.5%) had 2 or more discrete tumors of the same type, whereas 16 cats (10.0%) had 2 different types of intracranial tumors. The most common tumor types were meningioma (n = 93, 58.1%), lymphoma (n = 23, 14.4%), pituitary tumors (n = 14, 8.8%), and gliomas (n = 12, 7.5%). The most common neurological signs were altered consciousness (n = 42, 26.2%), circling (n = 36, 22.5%), and seizures (n = 36, 22.5%). Cats without specific neurological signs were common (n = 34, 21.2%). The tumor was considered an incidental finding in 30 (18.8%) cats. In addition to expected relationships (eg, meninges and meningioma, pituitary and pituitary tumors), we found that lesion location was predictive of tumor type with diffuse cerebral or brainstem involvement predictive of lymphoma and third ventricle involvement predictive of meningioma.     

A brief history of the prevention of infectious diseases by immunisations

Infectious diseases have always been a terrible scourge for humans. The appearance of these plagues, as they were called without distinction, was generally connected to various conditions: asters, climatic changes or religious reasons. The concept of contagious, and then infectious, diseases came slowly. Variolation, i.e. transmission of ‘virulent’ matter to induce a natural disease and the immunity against it, was brought from Constantinople to England by Lady Montague, in 1721. This ‘variolation’ technique was also often performed in veterinary medicine against diseases like sheep-pox or pleuropneumonia. As ‘vaccination’ is the term generally accepted for ‘immunisation’, variolation can be the word designating such a technique. The second period of the history of immunisation began, in 1880, with the studies of Pasteur and his collaborators. A great number of bacterial vaccines were developed: dead, live but attenuated or only parts of pathogens. The viruses were produced in animals, then in eggs and at last, in tissue cultures. Second generation vaccines appeared with genetic engineering: recombinant vaccines, vector vaccines, nucleic acids vaccines, and markers vaccines, among others. These novel technologies can permit the development of new ones and improve the quality of the vaccines already existing.     

Micronutrient Content of Certain Tropical Conventional and Unconventional Feed Resources of Southern India

The ash, silica and certain important micronutrients were estimated in conventional and unconventional feed and fodder resources available in Southern India. Commonly used dry roughages, such as paddy straw, ragi straw, maize kadbi/stalk, jowar kadbi/stalk, bajra stalk and wheat straw, were high in ash (9.9% +/- 0.77%) and silica (6.4% +/- 0.65%) and low in most of the other micronutrients, except iron, with paddy straw containing most silica (>9%). Cultivated non-leguminous (maize, jowar) and improved green crops (hybrid napier, guinea, green panic, NB-21, CO-1) were also high in ash (10.5% +/- 0.60% and 12.5% +/- 0.51%) but were moderate sources of P, Mg and Cu and good sources of Zn (98 +/- 13.8 ppm and 55 +/- 6.7 ppm). Leguminous green fodders (stylosanthus, lucerne, cow pea, soyabean) were excellent sources of Ca (1.9% +/- 0.16%), Mg (0.40% +/- 0.05%), Cu (30 +/- 5.2 ppm), Zn (121 +/- 14.7 ppm) and Fe (1234 +/- 166 ppm) and moderate sources of P. Mixed local grasses and weeds were high in silica (6.9% +/- 1.00%) but were good sources of Cu, Zn and Fe. Cereal grains (maize, wheat, rice, ragi) were low in ash (2.9% +/- 0.33%) and were relatively poor sources of Ca (0.22% +/- 0.03%), Mg (0.19% +/- 0.03%) and Cu (13 +/- 3.1 ppm). Pulses were low to medium sources of most minerals and good sources of Fe (1230 +/- 293 ppm). Oil seed cake/extractions (groundnut cake, cotton seed cake, soyabean meal, sunflower cake, safflower cake) and cereal by-products (rice polish, rice bran, wheat bran) were excellent sources of P (1.1% +/- 0.47% and 2.3% +/- 0.19%) and good sources of Zn (65 +/- 3.9 ppm and 66 +/- 10.7 ppm) and Fe (938 +/- 130 ppm and 662 +/- 126 ppm). Among the unconventional feeds screened, orange peel, sunflower heads, meat meal, rubber seed cake, spirulina algae and sea weeds contained plentiful Ca, Zn and Fe: tree leaves/top feeds (mulberry, erythrina, glyricidia, banana, subabul, groundnut haulms) were excellent sources of Ca (1.5% +/- 0.13%), Zn (120 +/- 22.9 ppm) and Fe (1033 +/- 133 ppm) but relatively poor sources of P. Soyabean husk, cocoa seed husk, rubber seed cake and meat meal were moderate to good sources of P (1.0% and 0.33%). The high Zn and Fe values of most feeds/fodders were probably due to soil contamination. This account of the micronutrient content of feed/fodder resources should help in strategic supplementation intended to alleviate local deficiencies.     

Bovine Mastitis in Selected Areas of Southern Ethiopia

A study on bovine mastitis, designed to determine the causal agents, prevalence of infection and impact of risk factors in three cattle breeds, was conducted in selected areas of southern Ethiopia. A total of 307 lactating and non-lactating cows, of which 162 were indigenous Zebu, 85 Jersey and 60 Holstein-Friesian, were examined by clinical examination and the California mastitis (CMT) test. Of these, 40.4% were positive by CMT and bacteriology for clinical or subclinical mastitis, with prevalence rates of 37.1% and 62.9%, respectively. Out of 1133 quarters examined, 212 (18.7%) were found to be infected, 83 (39.2%) clinically and 129 (60.8%) subclinically. The prevalence of mastitis was significantly higher in Holstein-Friesian than in indigenous Zebu, in non-lactating cows than in lactating cows, in the early lactation stage than in the mid-lactation stage, in cows with lesions and/or tick infestation on skin of udder and/or teats than in cows without this factor, and in the wet season than in the dry season. Mastitis increased with parity number (R = 0.9). Of 248 CMT and clinically positive udder quarter samples analysed microbiologically, 212 were culturally positive for known mastitis pathogens and 36 were negative. Of the 199 positive samples, Staphylococcus accounted for 39.2%, Streptococcus for 23.6%, coliforms for 14.1%, Micrococcus and Bacillus species for 8.0% each and Actinomyces or Arcanobacterium (Corynebacterium) for 7.0%. It was concluded that there was a high prevalence of clinical and subclinical mastitis, mainly caused by Staphylococcus aureus, Streptococcus agalactiae and Escherichia coli, in this study area.     

不同日粮氮水平对山羊氮代谢和微生物蛋白质合成的影响

本试验旨在探讨不同日粮氮水平对内蒙古白绒山羊氮代谢和微生物蛋白质合成(MCP)的影响,以达到提高氮利用率,减少环境污染和饲料资源的浪费。试验选用9只体况良好、体重为(43.83±2.95)kg,装有瘤胃瘘管的内蒙古白绒山羊,按体重随机分为3组,每组3只。日粮分为低氮7.5%、中氮10.5%、高氮13.5%3个氮水平。试验使用常规试验方法分析测定粪尿血液等生化指标,通过全收尿法和尿嘌呤衍生物法估测MCP。结果表明:随着氮水平增加,氨氮(NH3-N)浓度、氮摄入量、尿氮排出、尿中尿素氮(UUN)和MCP显著增加(P0.05),干物质采食量(DMI)显著降低(P0.01);沉积氮占总摄入氮的比例在中氮组最高,MCP在高氮组最高。综上所述,适当降低日粮氮水平可减少粪尿氮排放,提高反刍动物氮利用率。     

Microsporidial keratopathy in two dogs

A microsporidial keratopathy is described in two dogs. Both dogs presented with a unilateral stromal keratopathy characterized by multifocal coalescing opacities, and the diagnosis was made on histopathologic examination of keratectomy specimens. Transmission electron microscopy (TEM) on formalin‐fixed, paraffin‐embedded corneal tissue was performed in one dog, and the morphologic features were consistent with Nosema species infection. Both dogs were initially diagnosed and treated by superficial keratectomy. One dog received additional antifungal medication and underwent a penetrating keratoplasty following local recurrence two years later. No other systemic lesions attributable to the microsporidial infection were identified clinically. The clinical and diagnostic pathology findings, treatment, and follow‐up are discussed.