Observations on the occurence and specificity of anti-bodies produced by infected hosts against the acetyl-cholinesterase present in some common gastrointestinal nematode parasites

Sera from hosts infected with a variety of nematodes were examined for the presence of antibodies against nematode acetylcholinesterase (AChE). Antibodies were detected in the serum from hosts infected with Oesophagostomum spp., Ostertagia spp. and Trichostrongylus spp., but not in serum from hosts infected with Cooperia pectinata or Haemonchus spp., Toxocara spp. or Trichuris vulpis. In those infections in which anti-AChE antibodies were found, some individual animals failed to produce detectable antibodies. The enzyme appeared to possess antigenic specificity at the genus but not the species level.     

灌注寡肽与游离氨基酸对来航公鸡氨基酸吸收及循环中肽的影响

试验比较研究了在麻醉条件下来航公鸡十二指肠灌注酪蛋白水解物寡肽（COP）与游离氨基酸（FAA）对门静脉血液中氨基酸和肽的影响。结果表明：灌注后10分钟，COP组门静脉总氨基酸（TAA）含量显著地（P＜0．05）高于相同组成的等摩尔浓度的FAA1组和等百分浓度的FAA2组。FAA2与FAA1组相比，一些氨基酸含量有升高的趋势，但仅个别氨基酸显著（P＜0．05）高于FAA1组。COP组门静脉血浆游离氨基酸含量，除赖氨酸、色氨酸、酪氨酸、脯氨酸、组氨酸外，其它氨基酸都显著（P＜0．05）或极显著（P＜0．01）高于FAA1和FAA2组。在饥饿状态及灌注COP和FAA1、FAA2后，门静脉血浆中肽结合氨基酸（PBAA）分别占39．23％，35．63％，45．89％和52．63％。其中谷氨酸、丝氨酸、丙氨酸、甘氨酸比例较高，它们与其它一些氨基酸存在显著（P＜0．05）或极显著（P＜0．01）正相关。GPLC分析结果显示：灌注COP和FAA后门静脉血浆的肽量均极显著地（P＜0．01）高于饥饿对照状况，COP组鸡门脉血浆中总量和一些肽量显著高于FAA组（P＜0．01）。试验证实，鸡村寡肽的氨基酸吸收快于游离氨基酸，一部分可以完整的形式吸收进入血液循环。给予肠道FAA也会改变循环中的肽量。     

山豆根多糖对鸡免疫器官发育及体内活性氧水平的影响

为探讨山豆根多糖(SSP)对鸡免疫功能及体内抗氧化能力的影响,将山豆根多糖分别按50、100、200 mg/kg体重对14日龄公鸡胸部肌肉注射,在21、28、35、42日龄分别测定了鸡血浆中超氧化物歧化酶(SOD)活性、总抗氧化力(TAOC)、丙二醛(MDA)水平、谷胱甘肽(GSH)含量和一氧化氮(NO)的水平及鸡胸腺指数、脾脏指数和法氏囊指数。结果表明,鸡28日龄时,50～200 mg/kg山豆根多糖能显著提高鸡血浆中还原型谷胱甘肽水平(P0.05,P0.01);鸡35日龄时,50 mg/kg山豆根多糖能显著提高鸡的胸腺指数(P0.05),100 mg/kg山豆根多糖组鸡血浆中SOD活性极显著升高(P0.01),200 mg/kg山豆根多糖组鸡血浆NO水平显著升高(P0.01);鸡42日龄时,50 mg/kg山豆根多糖能显著提高鸡脾脏指数和法氏囊指数(P0.05),100 mg/kg山豆根多糖组鸡血浆中MDA水平极显著升高(P0.01)。提示山豆根多糖能够促进鸡免疫器官发育,并对鸡体内活性氧水平具有调节作用。     

Production and Identification of Clone Sheep Using Bone Marrow Mesenchymal Stem Cells as Donor Cell

In order to obtain the cloned sheep using bone marrow mesenchymal stem cells（BMSCs）as the donor cells,the BMSCs of sheep were chosen and reconstructed embryos were built to transfer.10 published microsatellite markers were chosen,and the DNA samples from clone sheep,donor cells and surrogate ewes were amplified,and the relationship of father-son（RCP）was analyzed using the Quantity One for genotyping.The results showed that the reconstructed embryos were successfully built for electric fusion using sheep BMSCs as nuclear donor,and making nuclear transplantation into enucleated mature oocytes of which the fusion rate was 80.62%.20 surrogate ewe were chosen to be implanted with the reconstructed embryos at morula stage by implant surgery,and 5 lambs were born and only 3 were survived.The genotype of cloned sheep was in line with the dornor cell and the RCP were more than 99.999%.In conclusion,the first clone sheep were obtained successfully by using BMSCs as a nuclear donor in this experiment.     

In vitro generation of mature neutrophils from canine Lin- bone marrow cells

The major goal of this work was to describe the in vitro generation of mature functional neutrophils derived from a canine enriched haematopoietic progenitor cell population. We have utilised lineage depletion by immunomagnetic selection to isolate a canine haematopoietic progenitor cell population. The physical, immunological, metabolical and morphological methodologies employed in this study have permitted us to isolate and define a cell population enriched in Rh-123low and CD34+ cells. Irradiated pre-established long-term bone marrow cultures (LTBMC) were utilised to determine the self-renewal ability of lineage negative (Lin-) cells, as well as their capacity to differentiate into mature functional neutrophils. The authors demonstrate for the first time that canine neutrophils derived from Lin- cells are able to produce oxyradicals, express a specific neutrophil surface antigen, and contain gelatinase granules. These characteristics enable them to migrate through basement membranes to act as a first line defence mechanism. The fact that these cells are able to differentiate into functional mature cells, and give rise to long-term culture-initiating cells (LTC-IC) after 35 days of culture, allows the authors to assure that the isolated canine enriched haematopoietic cell population exhibit functional characteristics, associated with primitive haematopoietic cells.     

Occlusion of the Middle Cerebral Artery: a New Method of Focal Cerebral Ischemia in Rats

The study in Wistar rats attempted to improve the occlusion technique of the middle cerebral artery (MCA) as a precise method for initiating stroke. In a first part it was necessary to study the exact anatomy of blood vessels of the brain in seven rats of 170-410 g body weight by corrosion cast. The lengths and diameters of defined locations of the blood vessels were measured. The temporary as well as the permanent methods were refined or replaced. The first one was completed in main training the physiological blood flow after temporary occlusion, while the permanent occlusion was performed by positioning a silicone cap in the MCA. A filament guide was introduced from the common carotid artery (CCA) via internal carotid artery (ICA) to guide the silicon cap at the branch of the MCA. Histological sections of the brain of rats showed 24 h after the permanent occlusion a reproducible infarct in the brain. This area corresponded very well with the supply of the MCA. The new occlusion method with a silicon cap was compared with the occlusion methods of CCA route and external carotid artery (ECA) route. The total infarct volume was significantly larger in the CCA route and ECA route groups than in the silicon cap group (means: CCA route 261 mm³; ECA route 191 mm³ vs. 128 mm³ silicon cap group; P  < 0,05). It could be demonstrated that the new silicon cap occlusion technique imitates the pathological situation of a cerebral infarct in man. Moreover it is less invasive for the animals and more precise and reproducible regarding the infarcted area in comparison to the other occlusion methods. Based on anatomical measurements of the blood vessels the described silicon cap method can be recommended for rats of a body weight between 340–370 g.     

Risk factors for an acute expression of Epizootic Rabbit Enteropathy syndrome in rabbits after weaning in French kindling-to-finish farms

Epizootic Rabbit Enteropathy (ERE) is a severe clinical syndrome of rabbits causing high economic losses for farmers. ERE first appeared in France in 1996. A retrospective case–control survey was carried out to identify the risk factors of acute expression of ERE, after weaning, in 96 kindling-to-finish rabbit farms in western France during 2001 and 2002. Farm status was defined according to the expression of clinical signs of ERE and mortality rates in the last five broiler rabbit batches. Comparisons of structural characteristics, rearing conditions and herd management showed that the risk factors for acute ERE expression were late weaning (rabbit age at weaning ≥ 35 days, RR = 4.44, 95% CI [1.36–21.71]), transfer of young rabbits at weaning (young rabbit transfer or combined practice RR = 2.83, 95% CI [1.16–9.33]), and high volume of the fattening room (air volume/rabbit weight in fattening room at weaning ≥ 0.14m³/kg, RR = 2.98, 95% CI [1.29–8.42]) and a high mortality rate in young rabbits before weaning (i.e. rate ≥ 10.5%; RR = 2.18, 95% CI [1.20–3.53]).     

生物防治与灭鼠剂不同组合对藏北地区鼠害的控制

为探讨藏北高寒草甸地区高原鼠兔(Ochotona curzoniae)的有效防治方法,在西藏安多县措玛乡草地设立了鹰架、招鹰灵与鹰架组合及D型肉毒梭菌毒素与鹰架组合的3个试验处理,同时进行藏北地区D型肉毒梭菌毒素最佳浓度的筛选及D型肉毒梭菌毒素和招鹰灵灭效对比试验.结果表明,质量分数为0.10%与0.15%的D型肉毒梭...     

伪狂犬病病毒在NF-κB家族p65基因敲除细胞系的复制规律研究

试验旨在研究伪狂犬病病毒（PRV）在NF-κB家族p65基因敲除细胞系中的复制规律。利用慢病毒介导的CRISPR/Cas9基因定点修饰技术构建猪肺泡巨噬细胞（3D4/21）p65基因稳定敲除细胞系。通过构建p65-sgRNA重组质粒,转染至HEK293T/17细胞,收取慢病毒,感染3D4/21细胞后利用嘌呤霉素筛选获得多克隆细胞系,T7核酸酶检测敲除效率,再通过有限稀释法获得3D4/21-p65^-/-的稳定细胞系。CCK-8试剂盒检测3D4/21细胞中敲除p65基因后对细胞增殖的影响;流式细胞术检测PRV-GFP感染3D4/21及3D4/21-p65^-/-细胞后病毒增殖的差异;实时定量PCR检测PRV感染3D4/21及3D4/21-p65^-/-细胞后PRV gB、TK基因mRNA表达水平及PRV感染细胞诱导的IL-1β和IL-6基因mRNA水平表达的变化;Western blotting检测PRV-QXX感染3D4/21及3D4/21-p65^-/-细胞后PRV gB、gE蛋白的表达;滴度测定检测PRV-QXX感染3D4/21及3D4/21-p65^-/-细胞后子代病毒滴度。结果表明,sgRNA2和sgRNA3的基因编辑效率较高,对其进行克隆化培养进而获得敲除p65基因的稳定表达细胞系;CCK-8试剂盒检测细胞活力表明,p65基因敲除对细胞活力无影响;流式细胞仪检测表明,同一时间点PRV-GFP在3D4/21-p65^-/-中的增殖显著高于对照细胞;实时荧光定量PCR表明在3D4/21细胞中敲除p65基因促进了PRV gB、TK基因的mRNA表达水平,而抑制了IL-1β、IL-6基因的mRNA表达;Western blotting结果表明,在3D4/21细胞中敲除p65基因促进了PRV gB、gE蛋白的表达;滴度测定结果表明,同一时间点PRV-QXX在3D4/21-p65^-/-细胞中子代病毒的复制显著高于对照细胞。以上结果均表明,p65基因敲除可促进PRV在3D4/21细胞中复制。     

不同酶制剂对水稻秸秆和白酒糟混合青贮品质的影响

为研究不同酶制剂对水稻(Oryzasativa L.)秸秆和白酒糟(m︰m=1︰1)混合青贮品质的影响,设置CK(对照)、CEL(250 U·g-1纤维素酶)和XYL(250 U·g-1木聚糖酶)3个处理,青贮120 d后取样测定其青贮品质.结果表明:CEL处理的感官评定等级为良好;CEL和XYL处理的干物质、粗脂肪、...