牛初乳sIgA等电点的测定

采用等电聚焦电泳法测定牛初乳sIgA的等电点。牛初乳sIgA的pI为5．02—5．67,比相关报道更加精确。回归方程：y=0．7543x＋3．1635,相关系数r=0．9989,表明线性关系良好,为牛初乳sIgA的离子交换层析制备条件的选择提供了可靠的理论依据。     

规模化屠宰场官方兽医及协检员的设置与职责

@@进入新世纪以来,伴随SARS、禽流感和猪链球菌病等疫情在全球范围内的传播,对世界各国人民的身体健康构成极大威胁。因此,国家逐步加大对动物疫病的防控,相继颁布了《中华人民共和国动物防疫法》《动物检疫管理办法》等法律法规,使我国动物防疫和检疫工作走上了有法可依、有章可循的规范化、法制化轨道。屠宰检疫是动物检疫工作的重要组成部分,是保证人民群众食肉安全的重要手段。猪肉及猪产品是广大群众餐桌上不可或缺的食品,国家为保证生猪产品质量安全,保障人民身体健康对生猪屠宰实行定点屠宰、集中检疫,从而使重大疫病的发生和流行得到有效控制。     

亚急性铜、镉暴露对鲤肝脏Hsp60表达的影响

试验通过实时定量PCR和Western blot技术,检测重金属铜、镉单一及联合急性暴露后鲤肝脏中Hsp60基因和蛋白水平。鲤随机分为7组,两个Cu2+处理组(0.05 mg/l和0.1 mg/l),两个镉处理组(0.63 mg/l和1.26 mg/l),两个混合处理组(0.045 mg/l和0.09 mg/l)和对照组。结果表明铜、镉单一及联合急性暴露对鲤有毒性作用,经过96 h的暴露,除混合低浓度组之外,其余各组肝脏中Hsp60基因表达水平显著提高(P0.05)。受重金属暴露的影响,初期鲤肝脏中Hsp60蛋白水平下降,随着时间推移,蛋白水平逐渐上升,混合低浓度组显著高于对照组水平(P0.05)。     

甘肃省民勤治沙综合试验站区域生态经济型优化模式的设计

以甘肃省民勤治沙综合试验站区域为系统，应用线性规划的方法，建立区域生态经济型系统的优化模式。结果表明，区域系统在现有的生产条件及生产力水平下，要达到最大经济效益，并保证区域系统的生态趋于良性特环 ，其农林牧三业用最优比例为１：９．５：９．５，此时区域系统的经济纯收入最大，为１１３．７２万元，年人均纯收入达５６８６元。     

野生动物种群格局分析方法

本文综述了几种种群格局分析方法，以苍鹭营巢的分布格局为例，探讨了这些方法在野生动物种群生态学上的应用，为研究野生动物种群的数量动态及其行为规律提供了理论基础。     

羊布鲁氏菌病直接经济损失与防控成本效益分析方法构建及实证研究

为了解我国布鲁氏菌病（以下简称“布病”）一类地区羊布病造成的直接经济损失及防控投入合理性,构建了羊布病直接经济损失指标体系和防控成本效益评估方法,并对我国羊主产区4省份17市县的防疫部门和319个养羊场户进行实地走访与问卷调查。共回收防疫部门问卷21份,场户有效问卷301份,涉及124个布病羊场和177个无布病羊场。运用Excel、SPSS等软件,对问卷数据进行统计分析。结果显示：2020年单只布病羊直接经济损失平均为4 557元（不含奶羊）,各省份羊布病损失为 1.8亿~20.4 亿元,其中养羊场户损失占比较高,占总损失的 73.0%~81.0%;各省份政府的布病防控效益成本比为5:1~38:1。结果表明,羊布病导致的经济损失严重,对其防控可取得显著经济效益。建议养殖户及政府进一步加大布病防控投入,而且政府应提高预防性投入比重。本研究为优化布病防控政策提供了技术支撑。     

Cloning, expression and characterization of monkey (Macaca fascicularis) CD137

CD137 plays an important role as a co-stimulatory molecule in activated T cells. Agonistic CD137 specific antibodies have been investigated as therapeutic agents to promote tumor-specific immune responses by direct activation of T cells. As part of the pre-clinical pharmacological evaluation of cynomolgus monkeys, monkey CD137 was cloned and characterized. The deduced amino acid sequence encoded a full-length gene of 254 amino acids 95% identical to human CD137. Sequence variants identified in monkey CD137 include four splice variants lacking the transmembrane domain. These variants were detectable in human including two previously unreported variants. Two missense single nucleotide polymorphisms were detected present in 42 and 50% of 36 monkeys tested. In both monkey and human, mRNA expression of full-length CD137 and splice variants were significantly increased in peripheral blood mononuclear cells (PBMCs) upon stimulation by anti-CD3 antibodies. Recombinant monkey CD137 protein was bound with high affinity by an agonistic anti-human CD137 antibody but not by an anti-mouse CD137 antibody. In summary, compared to human, monkey CD137 showed distinct extracellular domain amino acid sequence and sequence polymorphisms. Thus, antibodies directed against epitopes in this extracellular domain could have differences in pharmacologic activity between cynomolgus monkeys and human or across individual cynomolgus monkeys.     

Bactrian camel (Camelus bactrianus) integrins αvβ3 and αvβ6 as FMDV receptors: Molecular cloning, sequence analysis and comparison with other species

Integrins are heterodimeric adhesion receptors that participate in a variety of cell–cell and cell–extracellular matrix protein interactions. Many integrins recognize RGD sequences displayed on extracellular matrix proteins and the exposed loops of viral capsid proteins. Four members of the αv integrin family of cellular receptors, αvβ3, αvβ6, αvβ1 and αvβ8, have been identified as receptors for foot-and-mouth disease virus (FMDV) in vitro, and integrins are believed to be the receptors used to target epithelial cells in the infected animals. To analyse the roles of the αv integrins from a susceptible species as viral receptors, we have cloned Bactrian camel αv, β3 and β6 integrin cDNAs and compared them to those of other species. The coding sequences for Bactrian camel integrin αv, β3 and β6 were found to be 3165, 2289 and 2367 nucleotides in length, encoding 1054, 762 and 788 amino acids, respectively. The Bactrian camel αv, β3 and β6 subunits share many structural features with homologues of other species, including the ligand binding domain and cysteine-rich region. Phylogenetic trees and similarity analyses showed the close relationships of integrin genes from Bactrian camels, pigs and cattle, which are each susceptible to FMDV infection, that were distinct from the orders Rodentia, Primates, Perissodactyla, Carnivora, Galliformes and Xenopus. We postulate that host tropism of FMDV may in part be related to the divergence in integrin subunits among different species.     

松针饲用产品研究进展

松针含有丰富的营养物质和生物活性物质。它可以促进畜禽生长,提高动物的繁殖性能,改善动物产品质量,增强动物的防病能力。文章对松针的成分、松针粉在养殖业上的应用效果和松针饲用产品(松针粉、松针活性物质添加剂)的生产工艺进行了综述,并简要概括了松针产品的发展方向。     

胆固醇转运蛋白NPC1L1的研究进展

NPC1L1是近年来人们研究高脂血症的重点内容,该蛋白已被证实在胆固醇的肠道吸收和胆汁分泌中发挥了关键作用。NPC1L1调节体内胆固醇的生物合成,是维持生物体胆固醇动态平衡的重要因素,同时也是新型降脂药物依泽替米贝的作用靶点。