Physical, chemical, and serological characterization of avian rotaviruses

Physical, chemical, and serological characterization of rotavirus isolates from turkeys was done. Cesium chloride (CsCl)-gradient isopycnic centrifugation of infected cell cultures revealed the presence of rotavirus particles of three different densities. They were double-shelled, single-shelled, and core particles. The double-shelled particles had a buoyant density (in CsCl) of 1.34 g/cml3, and that of single-shelled particles in CsCl was 1.36 g/cm3. The buoyant density of core particles in CsCl was greater than 1.40 g/cm3. These rotavirus isolates were not inactivated by chloroform and were relatively stable at pH 3.0. Their replication was not affected by 5-bromo-2'-deoxyuridine. Avian rotaviruses were not completely inactivated by heat treatment of 56 C for 8 hr. All six avian rotavirus isolates examined were antigenically related to each other. However, there was no antigenic relationship between mammalian rotaviruses and the avian rotavirus isolates examined.     

Dimethylnitrosamine-induced liver fibrosis and recovery in NOD/SCID mice

There is a need for a new liver fibrosis model of immunodeficient mice to study the effects of cell therapy on liver disease because there are not many animal models available to study the effects of cell therapy. In this study, we induced liver fibrosis using dimethylnitrosamine (DMN) in NOD/SCID mice to create an animal model for liver disease. DMN (5 mg/kg, i.p.) was injected intraperitoneally for three consecutive days per week for 6 or 8 weeks, and the mice were sacrificed at weeks 0, 4 and 8 after the last DMN injection. The 6-week DMN-treated group gradually recovered from serum biochemical changes, histopathological toxic effects and lesions in the liver at weeks 4 and 8 after the last DMN injection. However, the progression of liver fibrosis and toxic levels were maintained in the 8-week DMN-treated group at week 4 after the last DMN injection. The increases in iron and extracellular matrix (collagen) in the DMN-treated group were confirmed by Prussian blue (PB) and Masson's trichrome (MT) staining, respectively. Additionally, activation of hepatic stellate cells was observed by alpha smooth muscle actin (α-SMA) immunostaining and western blot. In conclusion, treatment of NOD/SCID mice with 5 mg/kg of DMN for 8 weeks can be used to induce an appropriate animal model of disease for liver fibrosis. This model may be useful for evaluation of the efficacy and safety of cell therapies such as human mesenchymal stem cell therapy.     

In vitro neuronal and osteogenic differentiation of mesenchymal stem cells from human umbilical cord blood

Mesenchymal stem cells (MSCs) have the capabilities for self-renewal and differentiation into cells with the phenotypes of bone, cartilage, neurons and fat cells. These features of MSCs have attracted the attention of investigators for using MSCs for cell-based therapies to treat several human diseases. Because bone marrow-derived cells, which are a main source of MSCs, are not always acceptable due to a significant drop in their cell number and proliferative/differentiation capacity with age, human umbilical cord blood (UCB) cells are good substitutes for BMCs due to the immaturity of newborn cells. Although the isolation of hematopoietic stem cells from UCB has been well established, the isolation and characterization of MSCs from UCB still need to be established and evaluated. In this study, we isolated and characterized MSCs. UCB-derived mononuclear cells, which gave rise to adherent cells, exhibited either an osteoclast or a mesenchymal-like phenotype. The attached cells with mesenchymal phenotypes displayed fibroblast-like morphologies, and they expressed mesenchym-related antigens (SH2 and vimentin) and periodic acid Schiff activity. Also, UCB-derived MSCs were able to transdifferentiate into bone and 2 types of neuronal cells, in vitro. Therefore, it is suggested that the MSCs from UCB might be a good alternative to bone marrow cells for transplantation or cell therapy.     

早春短命植物绵果荠愈伤组织诱导相关因素研究

绵果荠是分布在新疆北部准噶尔荒漠中的十字花科一年生早春短命植物。本研究为探讨绵果荠愈伤组织诱导条件,以无菌苗子叶为外植体,研究了不同苗龄、培养基种类、蔗糖浓度和培养条件对愈伤组织的诱导及其生长的影响。结果表明,1)愈伤组织诱导的最佳条件为:苗龄14 d、培养基为MS+1.0 mg/L IBA+0.1 mg/L BAP、含糖量3%、温度25℃和光照为黑暗。2)愈伤组织生长的适宜条件是光照16 h/d和温度25℃。     

鸡β-防御素及其应用前景

防御素是生物界广泛存在的一类具微生物抗性的低分子肽，由于其抗菌谱最广，具有很高的应用潜力。本文概述了鸡β-防御素的分子结构、抗菌活性、基因表达调控的研究进展，并展望了其在畜牧业中的应用前景。     

湖南省某生猪批发市场疫病传播风险评估

为评估湖南省某生猪批发市场猪群疫病的发生风险,找出可能的风险因素,便于提出针对性预防措施,采用自行设计的调查问卷,结合访谈和现场调查,对27户经营户进行了调查,并将调查结果和调运数据相结合进行了疫病传播风险定性评估。结果显示:该市场疫病传入的可能性"高",内部传播的可能性"中等",疫病传出的可能性"高"。生猪调运频次多、数量大,经纪人行为复杂,运输车辆清洗消毒不彻底是可能的风险因素。评估结果提示,应尽量减少经纪人行为影响,重点加强对运输车辆的清洗消毒。     

新城疫病毒实时荧光RT-PCR检测方法的建立与应用

为满足新城疫病毒高通量快速检测的需要,针对新城疫病毒M基因序列,通过基因比对分析保守区域,经同源性分析后,设计合成多条引物和探针并对其筛选,建立了一种能够快速检测新城疫病毒的实时荧光RTPCR检测方法,并对该方法的特异性、灵敏性进行了评估。结果显示,该方法检测耗时短、特异性好,检测下限达10~(-4) ng/μL。利用该方法,对480份临床采集的各类家禽咽拭子样品进行检测,共检测出25份阳性,与常规RT-PCR检测方法结果一致,κ值为1(P 0.001)。结果表明,该方法快速、准确,可用于新城疫病毒的快速检测。     

Cutaneous lymphoma in a juvenile dog

Abstract: An 18-month-old male Doberman Pinscher was referred to the Veterinary Medical Teaching Hospital of the College of Veterinary Medicine for an erythemic nodular mass on the right forelimb. The mass was diagnosed as cutaneous lymphoma, based on cytologic examination of a mass aspirate and histopathology. Using immunohistochemistry the neoplastic cells were positive for CD3 but negative for CD79a, E-cadherin, and pancytokeratin, confirming their origin as T lymphocytes. No tumor recurrence was noted 18 months after surgery. To our knowledge, this is the first report of a solitary nodular form of cutaneous lymphoma in a young dog.     

病死畜禽处理的现状及其无害化处理技术

近年来出现的"黄浦江漂猪事件"和"江西高安病死猪事件",引发了人们对病死畜禽无害化处理问题的担忧。病死畜禽的无害化处理还存在养殖者不受重视、政府部门监管不到位、补贴政策落实不到位和处理技术落后等问题。本文分析了当前病死畜禽处理的现状,阐述了五种病死畜禽的无害化处理技术,并提出了4点对策建议。     

大蜡螟的生物学研究

在35±1℃,60～85%RH,全黑暗环境中用中蜂旧巢脾饲养的大蜡螟,其卵、幼虫、蛹、雌蛾、雄蛾的历期分别为8.6、49.4±9.4、10.8±1.9、5.5±2.6、9.2±3.3天.雌蛾平均产卵量为725.2 ± 148.3粒(258～1415粒).平均产卵前期为0.6天(0～2天).平均产卵期为4.3±0.8天,但平均有效产卵期只有3.4±0.6天.雌性蛹、蛾的体重比雄性蛹、蛾的极显著重,雌雄蛹重分别为162.1±5.1mg和122.2±1.9mg,雌雄蛾重分别为122.3±1.6mg和74.0±7.5mg.卵多产于0.23～0.27mm缝隙中,单层扁平成片,大小为0.34±0.04×0.34±0.06mm.