犬实验感染CDV的病理学研究

对实验感染犬瘟热病毒的病犬进行了系统的病理学观察，并用酶标ＳＰＡ法对病犬脏器组织中ＣＤＶ抗原进行了定位检查，结果表明淋巴系统各器官组织是ＣＤＶ急性感染早期首先侵犯的靶器官，脏器组织的病理改变与ＣＤＶ抗原出呈正相关，脏器组织中包涵体的检出与形态结构具有一定的特征性和示病意义，但采用免疫组化方法检查ＣＤＶ抗原，更具优越性，作者认为：ＣＤＶ９３０３９株和ＣＤＶ９３０４１株是致病力很强的泛嗜性ＣＤＶ。     

犬瘟热病毒的分离鉴定、致病特点和单克隆抗体的研究

犬瘟热是由犬瘟热病毒（ Ｃａｎｉｎｅ Ｄｉｓｔｅｍ ｐｅｒ Ｖｉｒｕｓ, Ｃ Ｄ Ｖ）引起的犬的一种高度接触传染性疾病。近年来,随着我国军、警犬、实验用犬和宠物犬饲养量的大幅度增加,以及异地交流的增多,犬瘟热在我国犬群中的发病率和致死率均有升高的趋势,而且临床表现也与以往有所不同。分析原因,除母源抗体干扰、疫苗效价低及使用不当外,犬群中是否出现了 Ｃ Ｄ Ｖ 新毒株亟待研究证实。本研究在从国内病犬分离到 Ｃ Ｄ Ｖ 的基础上,进行了 Ｃ Ｄ Ｖ 理化特性、致病特点、回归动物试验以及研制成功分泌抗 Ｃ Ｄ Ｖ 单克隆抗体,并进行了初步应用,取得了较为满意的研究结果。在研究中应用免疫组化方法进行病原检查,证实可很好地解决以往病理观察中无法进行病毒性疾病的特异性诊断的问题。１）采用免疫组化间接 Ｂ Ａ 法,对临诊疑似犬瘟热病犬脏器组织进行了 Ｃ Ｄ Ｖ 抗原定位检查及系统病理学观察。结果表明：发病犬大脑、小脑、心、肺、肝、脾、肠、肾、肾上腺、淋巴结、膀胱等组织细胞及血管内皮、支气管上皮细胞胞浆内均可见抗原阳性反应。同时,抗原阳性反应组织、器官均可见不同程度的病理变化。２）从病死犬肺、肝和淋巴结分离到 ２株 Ｃ Ｄ Ｖ,即 Ｃ Ｄ Ｖ９３０３９ 和      

猪圆环病毒发病机理的研究

通过口／鼻和静脉注射途径，用猪圆环病毒（ＰＣＶ）实验性感染未吮初乳仔猪，检查其病毒和抗原的分布，分别用病毒分离和冰冻切片间接免疫荧光抗体技术检查ＰＣＶ和抗原。结果，在机体组织中都检出了ＰＣＶ抗原，特别是在脾、胸腺和肺。中枢神经系统的组织中未检出ＰＣＶ抗原或病毒。检查自然发生流产／死胎母猪的胎儿，结果从同一农场两窝死产仔猪的２份血清和１份脾脏病料中分离出３株ＰＣＶ；检查１６０份胎儿血清，未检出ＰＣＶ     

免疫过氧化物酶法快速检测牛病毒性腹泻—粘膜病病毒抗原

用间接免疫过氧化物酶法（ＩＩＰ），对非细胞致病性牛病毒性腹泻－粘膜病（ＢＶＤ－ＭＤ）病毒持续感染的４２头牛血清经牛胎儿肌细胞培养检出了ＢＶＤ－ＭＤ病毒抗原，１００头外观健康牛的血清，经牛胎儿肌细胞培养未检出ＢＶＤ－ＭＤ病毒抗原，该结果与用干扰法获得的结果一致。而且用ＩＩＰ在血沉标黄层涂片中也检出了ＢＶＤ－ＭＤ病毒抗原，用亲和系－生物素过氧化物酶复合物方法在福尔马林固定的组织切片中也检出了ＢＶＤ－Ｍ     

NDV单苗,NDV／IBV联苗对鸡头部相关淋巴组织的影响

本文选用１０株ＮＤＶ疫苗、１０株ＮＤＶ／ＩＢＶ联苗，察接种２周龄雏鸡后对头部相关淋巴组织（ＨＡＬＴ）的影响。通过对接种鸡进行一系列体内试验，检测了哈德氏腺（ＧＨ）对布氏杆菌灭活抗原滴眼的反应情况。根据这一结果，对ＨＡＬＴ的几个部位和支气管进行组织学检查，并见到有微观变化。本研究表明：３种ＮＤＶ／ＩＢＶ联苗（１株Ｂ１／Ｍａｓｓ＆Ｃｏｎｎ、２株ＬａＳｏｔａ／Ｍａｓｓ＆Ｃｏｎｎ）可干扰ＧＨ对布氏抗原的反     

应用单克隆抗体夹心酶联免疫吸附试验检测兔出血症病毒

应用建立的单克隆抗体夹心酶联兔疫吸附试验（ＭｃＡｂ－ＥＬＩＳＡ）,检测了人工感染兔出血症病毒（ＲＨＤＶ）ＤＪＲＫ细胞毒、肝毒的兔以及自然感染ＲＨＤＶ的兔的组织样品。结果表明,感染死亡兔的肝、脾、肾、骨髓样品病毒抗原的检出率为１００％,淋巴结和肌肉的检出率分别为９７．５％和７９．５％。ＭｃＡｂ－ＥＬＩＳＡ能检出肌肉中血凝试验不能检出的ＲＨＤＶ抗原。此外,还用ＭｃＡｂ－ＥＬＩＳＡ检测了肝毒人工感染兔血中ＲＨＤＶ的动态,并对１０份兔出血症脏器灭活苗的效价作了滴定。     

马立克氏病（MD）胚胎免疫攻毒后病毒抗原的定位研究

本试验利用异硫氰酸荧光黄标记抗体和免疫金标记探针，对胚胎免疫攻毒试验鸡组织脏器中马立克氏病病毒（ＭＤＶ）抗原进行定位及动态观察。结果发现，不同组织细胞内ＭＤＶ抗原的表现形态略有不同，淋巴组织中阳性细胞内ＭＤＶ抗原多呈颗粒状或斑点状定位子细胞浆、细胞核内；脏器组织中阳性着染的实质细胞内病毒抗原则主要呈均匀弥散性分布于感染细胞（肾小管上皮细胞、肝细胞）的胞浆中而不发生瘤变。阳性细胞动态观察的结果则显示     

犬瘟热病毒小熊猫株(LP)的动物感染试验

将从死亡小熊猫肝脏病料中分离到ＣＤＶ ＬＰ株第９代ＭＤＣＫ细胞培养毒,按不同剂量各接种７只２～３月龄的健康幼犬,接种犬全部发病。于接种后７天时各捕杀２只犬进行检测,电镜检查、ＣＤＶ ＲＴ－ＰＣＲ、ＣＤＶ的分离及中和试验结果均为阳性,说明接种犬发生了ＣＤＶ感染。结合接种犬出现的临床症状及病理解剖学变化结果进行的分析表明,ＣＤＶ ＬＰ株是一株强毒,并且具有很强的免疫原性。人工感染犬试验结果表明某动物园     

马立克氏病病毒囊膜糖蛋白B抗原Ⅰ型特异性和群共同性决定簇的单克隆抗体

用能表达马立克氏病病毒（ＭＤＶ）糖蛋白Ｂ（ｇＢ）的重组杆状病毒感染的Ｓｆ９细胞免疫小鼠，制备针对ＭＤＶｇＢ的单克隆抗体。以Ⅰ型马立克氏病病毒ＧＡ株感染的鸡胚成纤维细胞作为检测抗原，同时以免疫荧光试验（ＩＦＡ）和酶联免疫吸附试验（ＥＬＩＳＡ）来筛选杂交瘤细胞，结果获得了ＩＦＡ和ＥＬＩＳＡ均为阳性的２株单克隆抗体细胞株，定名为ＢＡ４和ＢＤ８。在ＩＦＡ和免疫沉淀试验中，单抗ＢＤ８与Ⅰ、Ⅱ、Ⅲ型ＭＤＶ均呈阳性反应；单抗ＢＡ４只对Ⅰ型ＭＤＶ（包括ＣＶＩ９８８疫苗株）呈阳性反应。免疫沉淀反应进一步确证２株单抗识别的是ＭＤＶ糖蛋白Ｂ抗原。     

流行性出血热病毒气溶胶感染乳鼠的免疫病理学研究

采用免疫组化ＢＡ法，对流行性出血热病毒（ＥＨＦＶ）气溶胶感染乳鼠脏器组织中的病毒动态分布进行了观察，并对其抗体消长进行了测定。结果表明：①ＢＡ法为病理诊断ＥＨＦＶ感染提供了一种准确的手段；②ＥＨＦＶ可通过气溶胶途径感染乳小鼠，乳小鼠感染ＥＨＦＶ的ＬＤ５０值可作为环境浓度的参考值；③ＥＨＦＶ气溶胶途径感染乳鼠后，４ｈ即可在心、肺，１ｄ在嗅球部检出，并可在其组织细胞中增殖，经血循、嗅神经、单核巨噬细胞系统等多途径扩散，造成多组织脏器的泛发性感染。感染后１２～１４ｄ，病毒检出率和病毒量均达峰值。动物自身免疫系统对ＥＨＦＶ有一定的清除能力；④感染乳鼠脑、肺、肾等脏器组织的病变与人类感染ＥＨＦＶ的病变有一定的相似性，提示可作为人ＥＨＦＶ的模型动物；⑤抗原检出率高于抗体检出率，ＥＬＩＳＡ法检出率高于ＩＦＡ法检出率。     

Immunohistochemical demonstration of canine distemper virus antigen as an aid in the diagnosis of canine distemper encephalomyelitis

Brain tissue from 33 dogs with non-suppurative encephalitis was examined for evidence of canine distemper virus (CDV) encephalitis. Sections were examined for lesions, inclusion bodies, syncytial cells and CDV antigen using a double bridge unlabelled antibody enzyme technique. Histopathological lesions considered to be typical of granulomatous meningoencephalomyelitis were found in seven dogs. They all lacked inclusion bodies, syncytial cells and CDV antigen. The remaining 26 dogs all had histopathological lesions typical of CDV encephalitis. Inclusion bodies were found in 24 dogs, four of which also had syncytial cells and CDV antigen was detected immunocytochemically in 25. One dog had no inclusion bodies or syncytial cells and was immunohistochemically negative. Syncytial cells have been found to be of limited diagnostic value for the diagnosis of CDV encephalitis. While inclusion bodies proved to be a good diagnostic criterion for the confirmation of CDV infection, the immunohistochemical demonstration of CDV antigen proved to be superior. CDV antigen was more prevalent than inclusion bodies in tissue sections and much more easily detectable.     

Immunohistochemical detection of canine distemper virus in haired skin, nasal mucosa, and footpad epithelium: a method for antemortem diagnosis of infection.

A reliable antemortem diagnostic method is needed for determining infection with canine distemper virus (CDV). The utility of immunohistochemical detection of CDV antigen was examined was examined for samples of nasal and footpad epithelium and haired skin in dogs with and without detectable CDV antigen in the lung and/or brain. Tissues from 57 dogs at risk of CDV infection were tested. Viral antigen was found in the lung and/or brain of 28 dogs. Among these dogs, viral antigen was demonstrated in the epithelial cells of the nasal mucosa in 24 of 27 dogs, in the footpad epithelium in 24 of 26 dogs, and in the haired skin of the dorsal neck in 26 of 27 dogs. Among the 29 dogs without CDV antigen in either the lung or brain, 1 dog had positive staining for viral antigen in the skin and nasal mucosa. Biopsies of haired skin of the dorsal neck, which is relatively simple to sample, can be used for immunohistochemical testing for acute and subacute infection with CDV.     

Canine distemper virus infection of canine footpad epidermis

Infection of the footpad epidermis can occur in natural canine distemper virus (CDV) infection of dogs. Footpads from 19 dogs experimentally inoculated with virulent distemper strain A75/17 and from two nonexposed dogs were examined histopathologically and assessed for the presence of viral antigen and nucleoprotein mRNA, as well as number of inflammatory and apoptotic cells. Dogs were divided into four groups based on inoculation status and postmortem examination: inoculated dogs with severe distemper (group 1, n = 7); inoculated dogs with mild distemper (group 2, n = 4); inoculated dogs without distemper (group 3, n = 8); and noninoculated dogs (group 4, n = 2). Footpads from dogs of all groups had a comparably thick epidermis. Eosinophilic viral inclusions and syncytial cells were present in footpad epidermis of one dog of group 1. Footpads of group 1 dogs contained viral antigen and mRNA in the epidermis with strongest staining in a subcorneal location. Additionally, in these dogs footpad dermal structures including eccrine glands and vascular walls were positive for virus particles. No CDV antigen or mRNA was present in the footpad epidermis and dermis of any other dog. Group 1 dogs had more CD3-positive cells and apoptotic cells within the basal layer of the epidermis when compared to the other groups. These findings demonstrate that in experimental infection CDV antigen and mRNA were colocalized in all layers of the infected canine footpad epidermis. The scarcity of overt pathological reactions with absence of keratinocyte degeneration indicates a noncytocidal persisting infection of footpad keratinocytes by CDV.     

犬瘟热病毒间接免疫酶组化检测方法的建立

为对犬瘟热病毒(CDV)进行组织定位检查,本实验利用犬瘟热抗CDV单克隆抗体(MAb),采用间接免疫酶组化法对6只人工感染的比格犬肠组织的病毒抗原进行定位检测。结果表明,利用犬瘟热抗CDV MAb建立的间接免疫酶组化方法具有较高的特异性和灵敏性,可原位检测病犬肠组织中CDV抗原的分布,其抗原的阳性表达主要在小肠绒毛和李氏隐窝的上皮细胞胞浆内,表明CDV主要侵害小肠的粘膜上皮组织。     

Lymphoid apoptosis in acute canine distemper

The relationship between the canine distemper virus (CDV) infection and apoptosis in the canine lymphoid tissues was investigated using immunostaining for single stranded DNA (ssDNA), TdT-mediated dUTP-biotin nick end-labeling (TUNEL) method, and electron microscopy. Twenty-six lymphoid tissues from 8 spontaneously CDV-infected dogs and 1 non-infected dog were used, and lesions were classified into 4 groups according to frequency of the CDV-antigen. Histologically, the degree of lymphoid depletion tended to depend on amount of CDV antigen. The numbers of ssDNA- and TUNEL-labeling cells were significantly high in the lymphoid tissues with abundant viral antigen. However, ssDNA- and TUNEL-positive lymphocytes were also frequently found even in the lymphoid tissues where there was only a small amount of CDV-antigen in sinus histiocytes. The incidence and distribution of apoptotic cells in the CDV-antigens-negative lymphoid tissues from infected dogs were equal to those from a non-infected dog. Double labeling immunostaining using a ssDNA and a CDV nucleocapsid protein (CDV-NP) antibody revealed that there were ssDNA positive but CDV-NP negative cells besides those stained doubly positive. Ultrastructurally, lymphocytes in the CDV-infected lymphoid tissues frequently had characteristic morphological features of apoptosis such as apoptotic bodies. All these results suggest that CDV leads to lymphocytic apoptosis directly or indirectly, resulting in severe lymphoid depletion and immunosuppression in acute or subacute phase of CDV infection.     

Detection of IgM antibodies against a recombinant nucleocapsid protein of canine distemper virus in dog sera using a dot-blot assay

A dot-blot assay for the detection of IgM antibodies (ABs) against canine distemper virus (CDV) in canine serum is described. The diagnostic potential of this technique was evaluated by analysing sera from three test groups: (i) specific pathogen-free (SPF) beagle dogs experimentally infected with virulent CDV; (ii) SPF dogs immunized with a combined vaccine containing CDV, and (iii) SPF dogs immunized with a CDV-free vaccine. As antigen for the dot-blot assay we used the recombinant nucleocapsid protein (N protein) of the virulent A75/17 CDV strain. All 12 dogs of group 1, infected with virulent CDV, showed detectable CDV-specific IgM levels in their serum. All dogs of group 2 were also positive for anti-CDV IgM after the first immunization with the CDV-containing vaccine. The four dogs immunized with a CDV-free vaccine (group iii) remained negative throughout the course of the experiment. From these results, we conclude that the IgM detection test, which requires only a single serum sample, is a useful method for diagnosing current or recent CDV infection in CDV-infected or CDV-immunized dogs under experimental conditions.     

Magnetic resonance imaging findings in acute canine distemper virus infection

Demyelination is the prominent histopathological hallmark in the acute stage of canine distemper virus infection. Magnetic resonance imaging is an important diagnostic tool in human beings to determine demyelination in the brain, for example in multiple sclerosis. Five young dogs with clinically suspected canine distemper virus infection were subjected to magnetic resonance imaging of the brain and histopathological and immunohistochemical examinations. Hyperintense lesions and loss of contrast between grey and white matter were detected in T2-weighted images in the cerebellum and/or in the brainstem of three dogs, which correlated with demyelination demonstrated in histopathological examination. Furthermore, increased signal intensities in T2-weighted images were seen in the temporal lobe of four dogs with no evidence of demyelination. Magnetic resonance imaging seems to be a sensitive tool for the visualisation of in vivo myelination defects in dogs with acute canine distemper virus infection. Postictal oedema and accumulation of antigen positive cells have to be considered an important differential diagnosis.     

Immunoperoxidase study of canine distemper virus pneumonia

Forty-two cases of canine pneumonia were examined for the presence of canine distemper virus. For that purpose canine distemper virus inclusion bodies were located. The histopathological lesions were related to the presence of canine distemper antigen, as demonstrated with an immunoperoxidase technique. This technique was more sensitive for detecting canine distemper infection in lung tissue than was the study of inclusion bodies. Attention was also paid to combined infection with canine adenovirus and Bordetella bronchiseptica.     

Comparison of tissue and fluid samples for the early detection of canine distemper virus in experimentally infected dogs

The clinical utility of various specimens was examined for the early diagnosis of canine distemper (CD). Seven healthy dogs at 17 weeks of age were experimentally infected with a field isolate of canine distemper virus. The RT-PCR was carried out to detect CDV NP gene. Dogs showed mild fever and leukopenia, however, typical clinical signs of CD were not seen through the experimental period. CDV amplicons were detected more, earlier and for longer period in the conjunctival swabs than in the other samples employed. These results suggested that conjunctival swab samples, which are easy to obtain and non-invasive, would be the most suitable and practical specimen for the early antemortem diagnosis of CDV infection.     

Phenotypical characterization of T and B cell areas in lymphoid tissues of dogs with spontaneous distemper

CD3, CD4, CD5, and CD8 antigen expression of T cells and IgG expression of B cells and canine distemper virus (CDV) antigen distribution were immunohistochemically examined in lymphoid tissues (lymph node, spleen, thymus, and tonsil) of control dogs and animals with spontaneous canine distemper. In addition, CNS tissue of all animals was studied for neuropathological changes and CDV antigen distribution. Based on the degree of depletion distemper dogs were classified into two groups. Group I represented animals with moderate to marked lymphoid depletion, while group II dogs displayed mild or no depletion. CDV antigen was mainly found in lymphocytes and macrophages of group I dogs, whereas CDV expression was most prominent in dendritic cells of group II animals. In group I dogs, a marked loss of CD3, CD4, CD5, CD8, and IgG expression was noticed, hereby loss of CD4+ cells was more prominent than depletion of CD8+ cells. In the lymphoid tissues of group II animals, a significant increase in the number of T and B cells was observed compared to group I dogs. The number of CD3+, CD4+, and CD8+ cells in group II dogs was similar to the findings in controls, however, CD5 and IgG expression was mildly reduced in T and B cell areas, respectively. Additionally, in groups I and II dogs, CD3+ and CD5- T cells were detected in T cell areas. Whether this cell population represents a cell type with autoimmune reactive potential remains to be determined. Surprisingly in group II animals, viral antigen was found predominantly in dendritic cells indicating a change in the cell tropism of CDV during chronic infection and a possible mechanism of viral persistence. The two patterns of lymphoid depletions correlated to two different types of canine distemper encephalitis (CDE). Group I dogs displayed acute non-inflammatory CDE, whereas group II dogs suffered from chronic inflammatory demyelinating CDE, indicating a pathogenic relationship between lymphocytic depletion and inflammatory brain lesions in distemper.