PEDV分离株S1基因的重组杆状病毒真核表达

为了研究猪流行性腹泻病毒(porcine epidemic diarrhea virus,PEDV)分离株(PEDV/LA/2014/02)纤突蛋白(S1)的真核表达及其反应原性,本研究利用杆状病毒真核表达系统表达出重组His-PEDV-S1蛋白。利用在线软件分析PEDV S1基因在sf9细胞内的稀有密码子,经优化密码子后的基因进行人工合成,合成后的PEDV S1基因被克隆至杆状病毒的穿梭载体(pFastBac HT A)中,转化大肠杆菌DH10Bac感受态细胞进行重组,PCR方法验证后将重组成功的杆状病毒基因组转染sf9细胞,获得包装成功的杆状病毒,该病毒进一步接种sf9细胞,显微镜观察重组病毒引起的细胞病变,RT-PCR方法验证PEDV S1基因的mRNA表达水平,SDS-PAGE、Western blotting方法验证重组PEDV S1蛋白的表达及其反应原性。结果显示,试验成功构建了重组穿梭质粒pFastBac HT A-PEDV-S1(pSL598),成功包装表达了PEDV S1的重组杆状病毒,重组杆状病毒能使sf9细胞出现细胞变大、胞内有空泡等典型病变,PEDV S1基因的mRNA获得表达,重组蛋白His-PEDV-S1在sf9细胞中得到表达,蛋白质大小为83 ku左右,主要存在于细胞沉淀中,表达的重组蛋白能与小鼠抗His抗体和猪抗PEDV阳性血清反应,说明该蛋白具有较好的反应原性。本研究为研制PEDV新流行毒株新型亚单位疫苗和防控该毒株的流行提供了材料。     

表面展示猪流行性腹泻病毒纤突蛋白S1的重组杆状病毒及其免疫效果研究

猪流行性腹泻病毒(porcine epidemic diarrhea virus,PEDV)纤突蛋白S1能够介导宿主抵御PEDV感染的中和抗体的产生,是PEDV基因工程疫苗研究的重要靶抗原。将PEDV的S1基因克隆至杆状病毒基因组中,构建包含PEDV S1基因的重组杆状病毒,使S1蛋白表面展示表达。以该重组病毒作为活载体疫苗皮下接种BALB/c小鼠,验证S1蛋白在重组杆状病毒中的表达及其免疫原性。Western blotting分析被重组杆状病毒感染的Sf9细胞中,PEDV S1蛋白能有效表达且呈现大小分别约120 k D和150 k D的2条带,其中前者至少比预期大30 k D左右,推测重组S1蛋白在Sf9细胞中被高度糖基化修饰。重组杆状病毒的胶体金免疫电子显微镜观测结果显示S1蛋白展示于杆状病毒表面;间接ELISA试验结果证明重组杆状病毒可以诱导产生PEDV特异性抗体,抗体效价达到1∶5 000。血清中和试验及淋巴细胞增殖试验结果证明,该重组杆状病毒能够激发有效的体液免疫及细胞免疫反应,S1蛋白在重组杆状病毒表面展示表达并具有免疫原性。     

PEDV分离株S1基因的重组杆状病毒真核表达

为了研究猪流行性腹泻病毒(porcine epidemic diarrhea virus,PEDV)分离株(PEDV/LA/2014/02)纤突蛋白(S1)的真核表达及其反应原性,本研究利用杆状病毒真核表达系统表达出重组His-PEDV-S1蛋白。利用在线软件分析PEDV S1基因在sf9细胞内的稀有密码子,经优化密码子后的基因进行人工合成,合成后的PEDV S1基因被克隆至杆状病毒的穿梭载体(pFastBac HT A)中,转化大肠杆菌DH10Bac感受态细胞进行重组,PCR方法验证后将重组成功的杆状病毒基因组转染sf9细胞,获得包装成功的杆状病毒,该病毒进一步接种sf9细胞,显微镜观察重组病毒引起的细胞病变,RT-PCR方法验证PEDV S1基因的mRNA表达水平,SDS-PAGE、Western blotting方法验证重组PEDV S1蛋白的表达及其反应原性。结果显示,试验成功构建了重组穿梭质粒pFastBac HT A-PEDV-S1(pSL598),成功包装表达了PEDV S1的重组杆状病毒,重组杆状病毒能使sf9细胞出现细胞变大、胞内有空泡等典型病变,PEDV S1基因的mRNA获得表达,重组蛋白His-PEDV-S1在sf9细胞中得到表达,蛋白质大小为83 ku左右,主要存在于细胞沉淀中,表达的重组蛋白能与小鼠抗His抗体和猪抗PEDV阳性血清反应,说明该蛋白具有较好的反应原性。本研究为研制PEDV新流行毒株新型亚单位疫苗和防控该毒株的流行提供了材料。     

表达PEDV中国变异株S基因重组猪伪狂犬病病毒的构建和纯化

为了研制出能够同时预防猪流行性腹泻病毒(porcine epidemic diarrhea virus,PEDV)和猪伪狂犬病病毒(pseudorabies virus,PRV)感染的二联活疫苗,本研究将增强型绿色荧光蛋白(EGFP)和PEDV中国变异株的纤突蛋白免疫决定簇区域(S1)基因分别克隆至含有PRV胸苷激酶(TK)基因上、下游同源臂的穿梭载体pTK中,构建重组PRV转移质粒pTK-EGFP和pTK-S1。将重组质粒pTK-EGFP与PRV疫苗毒株Bartha-K61基因组DNA共转染Vero细胞,经绿色荧光蚀斑纯化得到重组病毒rPRV-EGFP。随后将重组质粒pTK-S1与rPRV-EGFP基因组DNA共转染Vero细胞,通过反向筛选EGFP阴性蚀斑,蚀斑纯化得到表达PEDV S蛋白的重组伪狂犬病病毒rPRV-S1。本研究将为更有效防控猪伪狂犬病和猪流行性腹泻提供辅助工具。     

稳定表达3种猪腹泻病毒嵌合抗原的CHO细胞系构建与鉴定

为构建稳定表达猪流行性腹泻病毒(PEDV)、猪胃肠炎病毒(TGEV)和猪Delta冠状病毒(PDCoV)主要抗原的CHO细胞系，为猪病毒性腹泻三联疫苗的研发提供基础材料，本研究将PEDV的S基因的COE区域、TGEV和PDCoV的S基因的受体结合区域(RBD),通过同源重组的方式进行融合，克隆到慢病毒表达质粒pLV-EF1a-IRES-Puro中，包装得到重组慢病毒。使用重组慢病毒感染CHO细胞，经过嘌呤霉素和单克隆细胞筛选，基因水平和蛋白水平表达验证，成功构建了稳定表达3种猪腹泻病毒抗原融合蛋白的CHO细胞系，为进一步研制PEDV-TGEV-PDCoV的亚单位疫苗奠定了基础。     

猪流行性腹泻病毒S1基因的克隆及在腺病毒中的表达

为了研究猪流行性腹泻病毒(PEDV)S1基因在腺病毒中的表达,试验采用RT-PCR方法,获得S1目的基因序列,并将其定向克隆至腺病毒穿梭质粒pShuttle-CMV,再与BJ5183细菌内的腺病毒骨架质粒pAdEasy-1进行同源重组,获得携带猪流行性腹泻病毒S1基因的重组腺病毒质粒pAd-S1;该重组质粒经PacⅠ酶切、转染AD-293细胞,获得具有感染性的重组腺病毒rAd-S1;病毒效价在传至第6代时可达到1×108.3TCID50/mL,同时经PCR检测,目的基因在重组腺病毒rAdS1传代过程中稳定存在;间接免疫荧光检测和Western-blot检测,rAd-S1在AD-293细胞中成功表达出分子质量约为100 ku猪流行性腹泻病毒S1蛋白。说明构建的重组腺病毒rAd-S1能够稳定地表达PEDV S1蛋白。     

变异猪流行性腹泻病毒(PEDV)S和N融合双基因质粒的构建及鉴定

为构建变异猪流行性腹泻病毒(PEDV)的S和N融合双基因质粒并表达出相应的蛋白,通过扩增变异PEDV的S和N基因,将S基因连接到pEAS-Blunt M2(M2)真核表达载体,构建M2-S质粒,通过同源重组原理,采用无缝拼接试剂盒将N基因克隆至M2-S基因片段,再转化到Trans1-T1感受态细胞中,构建M2-S-N融合双基因质粒。将M2-S-N融合双基因质粒转染到293T细胞,可表达出相应的S-N融合双基因蛋白。利用RT-PCR、Western blot技术和免疫BLAB/c鼠试验鉴定载体及蛋白表达的免疫活性,结果成功构建了M2-S-N融合双基因质粒,并表达出具有免疫原性的S-N融合双基因蛋白,且该蛋白能够诱导小鼠产生特异性抗体。变异PEDV的S和N基因融合双基因质粒的构建,为进一步开展变异PEDV的诊断技术及基因工程疫苗等研究奠定良好基础。     

猪流行性腹泻病毒纤突蛋白S1主要抗原表位区原核表达及其抗血清中和活性鉴定

本研究利用生物信息学软件预测了猪流行性腹泻病毒(porcine epidemic diarrhea virus,PEDV)S1蛋白的1个B细胞中和线性表位。为了验证S1蛋白中该表位的存在,并鉴定其中和活性,构建含有该B细胞线性表位截短S1基因的重组质粒pGEX-4T-S1,通过蛋白电泳和Western blot确定该重组质粒可以在原核细胞中表达。将该重组蛋白纯化,免疫BALB/c小鼠,3次免疫后,眼眶静脉采血进行间接免疫荧光及中和试验。结果表明,截短S1蛋白能够引起机体的体液免疫反应,该免疫血清能有效中和PEDV,中和效价为1∶64。该研究结果对PEDV免疫机制和新型疫苗的研究具有重要的借鉴意义。     

变异猪流行性腹泻病毒M和N融合双基因的原核表达及表达产物免疫原性分析

旨在构建变异猪流行性腹泻病毒(PEDV)的M和N双基因融合质粒,并分析表达蛋白免疫原性。通过扩增变异PEDV FJFQ2014毒株(GenBank登陆号KJ646580)的M基因和N基因,将M基因克隆至pEASY-Blunt E2(pE2)表达载体,构建出pE2-M质粒。利用同源重组原理,采用无缝拼接试剂盒将N基因克隆至E2-M片段,转化到Trans 1-T1感受态细胞中,构建出pE2-M-N融合双基因质粒并转化Transetta(DE3),表达出相应的融合蛋白,采用SDS-PAGE和Western blot验证蛋白的表达情况。将纯化的M-N融合蛋白皮下接种BLAB/c小鼠,通过ELISA方法检测融合蛋白的免疫原性。结果表明:扩增出M和N基因,成功构建了pE2-M质粒,并将E2-M基因与N基因进行有效连接,构建出pE2-M-N融合双基因质粒,表达出了具有免疫原性的M-N融合蛋白,该蛋白能够诱导小鼠产生相应的特异性抗体。变异PEDV的pE2-M-N双基因融合质粒的构建,为进一步开展变异PEDV的诊断技术和免疫学等研究,奠定良好基础。     

猪流行性腹泻病毒S1蛋白表达及反应原性分析

为了获得反应原性较好的猪流行性腹泻病毒(PEDV)S1蛋白,利用原核表达系统对S1基因(60~845 bp)进行扩增并构建原核表达质粒,转化至大肠杆菌BL21(DE3),以1 mmol/L IPTG诱导表达4 h,进行SDS-PAGE和Western blot分析。结果显示:成功构建了pET-30A-S1质粒,重组蛋白得到了表达且具有良好的反应原性,能够被兔PEDV多抗血清识别。本研究为进一步建立ELISA检测方法和亚单位疫苗的研制奠定了物质基础。     

商会自治的基石——商会自治规范研究

在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。     

癸氧喹酯干混悬剂含量测定的改进

采用高效液相色谱法测定癸氧喹酯干混悬剂的含量,在2-250μg/mL范围内,峰面积的常用对数与进样量浓度的常用对数呈良好的线性关系,R^2=1(n=5),平均回收率为99.24%~99.51%,RSD在0.05%~0.28%。此方法分析时间短,样品前处理简便、定量结果准确,重现性好,结果满意,为其质量控制提供了依据。     

猪毛色遗传的研究进展

本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。     

Comparison of 2 methods of centesis of the bursa of the biceps brachii tendon of horses

REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air.     

不同样本商品蜂蜜中硒含量的测定

用硝酸和高氯酸消化蜂蜜,使硒游离出来,在微酸性环境下,硒和2,3-二氨基萘(DAN)生成有较强荧光的物质,用环己烷萃取,在激发波长378nm,荧光波长518nm处测定其荧光强度。蜂蜜中硒含量范围:0.10～0.82μg/g。表明:蜂蜜应视为天然富硒营养品。     

乳酸杆菌益生作用机制的研究进展

乳酸杆菌作为益生菌广泛用于人和动物。本文综述了乳酸杆菌改善宿主健康的机制。乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道。文章重点讨论了乳酸杆菌表面成分（表面蛋白、脂磷壁酸和肽聚糖）与肠道受体（Ｃ型凝集素受体、Ｔｏｌｌ样受体和 Ｎｏｄ样受体）,阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制。     

Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF

Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo.     

Mechanism of Action of Probiotic Function of Lactobacilli

乳酸杆菌作为益生菌广泛用于人和动物.本文综述了乳酸杆菌改善宿主健康的机制.乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道.文章重点讨论了乳酸杆菌表面成分(表面蛋白、脂磷壁酸和肽聚糖)与肠道受体(C型凝集素受体、Toll样受体和Nod样受体),阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制.     

Evaluation of serum concentrations of biomarkers of skeletal metabolism and results of radiography as indicators of severity of osteochondrosis in foals

OBJECTIVE: To determine whether serum concentrations of biomarkers of skeletal metabolism can, in conjunction with radiographic evaluation, indicate severity of osteochondrosis in developing horses. ANIMALS: 43 Dutch Warmblood foals with varying severity of osteochondrosis. PROCEDURE: 24 foals were monitored for 5 months and 19 foals were monitored for 11 months. Monthly radiographs of femoropatellar-femorotibial and tibio-tarsal joints were graded for osteochondral abnormalities. Serial blood samples were assayed for 8 cartilage and bone biomarkers. At the end of the monitoring period, foals were examined for macroscopic osteochondrosis lesions. RESULTS: Temporal relationships were evident between certain serum biomarkers and osteochondrosis severity in foals during their first year. Biomarkers of collagen degradation (collagenase-generated neoepitopes of type-II collagen fragments, type-I and -II collagen fragments [COL2-3/4C(short)], and cross-linked telopeptide fragments of type-I collagen) and bone mineralization (osteocalcin) were positive indicators of osteochondrosis severity at 5 months of age. In foals with lesions at 11 months of age, osteochondrosis severity correlated negatively with COL2-3/4C(short) and osteocalcin and positively with C-propeptide of type-II procollagen (CPII), a collagen synthesis marker. Radiographic grading of osteochondrosis lesions significantly correlated with macroscopic osteochondrosis severity score at both ages and was strongest when combined with osteocalcin at 5 months and CPII at 11 months. CONCLUSIONS AND CLINICAL RELEVANCE: The ability of serum biomarkers to indicate osteochondrosis severity appears to depend on stage of disease and is strengthened with radiography. In older foals with more permanent lesions, osteochondrosis severity is significantly related to biomarker concentrations of decreased bone formation and increased cartilage synthesis.