鸡源志贺菌IpaC蛋白单抗制备及其受体的初步鉴定

为制备特异性的鸡源志贺菌IpaC蛋白单克隆抗体和鉴定其受体,以纯化的重组鸡源志贺菌IpaC蛋白制备多克隆抗体,Western blot和间接ELISA分析表明重组IpaC蛋白具有很好的免疫反应原性。将纯化的IpaC蛋白免疫BALB/c小鼠,通过淋巴细胞杂交瘤技术制备单克隆抗体。经过杂交瘤细胞阳性孔的筛选、单克隆抗体效价测定、单克隆抗体亚型鉴定、单克隆抗体Western blot鉴定后,获得1株杂交瘤阳性细胞5A12B5。同时,通过鸡胚肠组织提取总蛋白,利用铺覆蛋白印迹技术,初步测定IpaC蛋白受体相对分子质量约为55 000。试验为IpaC蛋白检测和该蛋白与鸡肠上皮细胞之间的相互作用研究奠定基础,同时也为评估鸡源志贺菌在公共卫生等方面的重要性提供参考依据。     

细胞信号转导和骨架在人源福氏志贺菌侵袭鸡肠上皮原代细胞中的作用

为研究细胞信号转导和骨架在人源福氏志贺菌侵袭鸡肠上皮原代细胞中的作用,分别用酪氨酸蛋白激酶、酪氨酸蛋白磷酸酶、蛋白激酶C、Ca2+通道等信号转导抑制剂染料木黄酮、原钒酸钠、星状孢子素、硝苯地平和微丝蛋白聚合抑制剂细胞松弛素B处理鸡肠上皮原代细胞后,采用细胞免疫组织化学染色检测人源福氏志贺菌ZD02株对鸡肠上皮原代细胞侵袭率,用间接免疫荧光双重标记检测ZD02株侵袭鸡肠上皮原代细胞后F-肌动蛋白分布的变化。结果显示,染料木黄酮、硝苯地平和细胞松弛素B能显著抑制人源福氏志贺菌ZD02株内化,星状孢子素和原钒酸钠对ZD02株的内化无影响,人源福氏志贺菌侵袭鸡肠上皮原代细胞时F-肌动蛋白发生聚集。本研究表明人源福氏志贺菌ZD02株侵袭鸡肠上皮原代细胞过程中需要酪氨酸蛋白激酶、Ca2+通道活化以及细胞微丝重排。     

鸡源志贺菌IpaC基因变构体重组酵母表达载体的构建及初步表达

为使IpaC基因表达产物保持天然的生物学活性,实现在酵母表达系统中高效表达,本研究首先采用反向PCR将IpaC基因358~360位和361~363位酵母菌低频密码子突变为偏嗜性密码子,并进一步构建了克隆载体pMD18-T-IpaC*和酵母表达载体pPICZαA-IpaC*,然后将线性化重组质粒pPICZαA-IpaC*电转化至毕赤酵母X-33中,对阳性转化子进行诱导表达,并用SDS-PAGE检测其表达产物。结果表明SDS-PAGE在大约63 000处检测出目的条带,实现了鸡源志贺菌IpaC基因在毕赤酵母中的初步表达。这为进一步研究IpaC生物学功能奠定了基础。     

人源福氏志贺菌对鸡肠上皮原代细胞侵袭特性研究

为研究人源福氏志贺菌对鸡肠上皮原代细胞侵袭力和侵袭特性,进一步验证人源志贺菌对鸡的致病性并建立体外研究模型,采用Hela细胞庆大霉素保护试验和免疫组织化学染色检测分离的人源福氏志贺菌ZD02株的毒力。然后采用细胞免疫组织化学染色研究ZD02株对鸡肠上皮细胞的侵袭力和相关侵袭特性。人源福氏志贺菌ZD02株能够侵入Hela细胞,庆大霉素保护试验结果显示,感染后30、60、90、120min时ZD02株侵袭率分别为1.43%、2.43%、2.56%、2.62%,证明ZD02株具有毒力。ZD02株侵袭鸡肠上皮原代细胞免疫组织化学检测结果显示,ZD02株能侵入鸡肠上皮细胞,感染后1、2、3、4h时ZD02株侵袭率分别为1.7%、6.2%、8.0%、11.2%。鸡肠上皮原代细胞经EGTA处理后,ZD02株侵袭率显著提高。人源福氏志贺菌ZD02株对鸡肠上皮细胞具有侵袭力,且从肠上皮细胞基底侧部侵袭。本研究进一步验证了志贺菌人禽互传的可能性,鸡肠上皮原代细胞可作为研究志贺菌致病机理的体外模型。     

鸡源志贺氏菌IpaC基因新型表达载体构建及其在毕赤酵母中的表达

为使鸡源志贺氏菌IpaC蛋白保持天然的生物学活性,在毕赤酵母表达系统中实现分泌表达,进一步研究IpaC蛋白的生物学功能,本研究在不改变IpaC蛋白氨基酸序列的情况下,根据酵母密码子偏爱性优化合成IpaC#基因,利用真核表达载体p GAPZA和8种真核信号肽,分别构建真核表达载体pGAPZA-Inu/Inv/Kil/Lys/Mat/Amy/Glu/Ser-IpaC#,然后将线性化的重组质粒电转化至毕赤酵母X-33中,对阳性转化子进行表达,并用SDS-PAGE及Western-blot检测其表达产物。结果表明:在8种重组菌表达产物的菌体沉淀中检测到大小约为60 ku的目的蛋白。说明鸡源志贺氏菌IpaC基因成功实现了在毕赤酵母的胞内表达。     

鸡胚组织膜蛋白与鸡毒霉形体黏附蛋白的结合分析

利用pGEX融合蛋白表达系统,将鸡毒霉形体黏附蛋白（pMGA）与GST的编码序列在大肠杆菌BL21中进行融合表达,经GST·BindResin纯化,GST—pMGA的纯度达96％。用蛋白酶Thrombin切掉GST标签,获得纯度为96％的pMGA,经Western—blot鉴定具有良好的免疫学活性。通过差速离心法提取SPF鸡胚的气管、心脏、肝脏、肺脏、肾脏、腺胃、十二指肠、法氏囊、胸腺和脾脏等组织膜蛋白,采用斑点酶联免疫吸附试验（Dot—ELISA）检测各组织膜蛋白与pMGA的结合。结果表明：除脾脏外,其余组织的膜蛋白与pMGA之间存在特异性结合,说明这些组织膜蛋白中存在pMGA的受体蛋白。经SDS-PAGE分析发现,除脾脏外,其余9种组织的膜蛋白中均含有一条相对分子质量约为30ku的主带,受体的相对分子质量可能为30ku,可为深入研究pMGA的受体蛋白提供资料。     

兔出血症病毒肝脏表面蛋白受体的初步筛选

为了筛选鉴定兔出血症病毒(RHDV)感染的肝脏细胞表面受体,取成年兔肝脏组织以胰酶消化,经300目铜网过滤,得到完整的兔肝脏细胞。用生物素对细胞表面蛋白进行标记和分离;采用病毒铺覆蛋白技术分析兔肝脏细胞表面蛋白。结果表明,在130 000~170 000的位置上存在与RHDV相互作用的特异性蛋白条带;利用液相色谱联合质谱技术(LC MS/MS)对特异蛋白条带进行shotgun分析,鉴定得到38个候选蛋白,其中3种蛋白在已知病毒感染过程中具有重要作用。     

鸡肠上皮细胞原代培养与鉴定

为了探讨鸡肠上皮细胞体外分离培养方法,进一步研究鸡源志贺菌Ipa C毒力蛋白在鸡肠上皮细胞上的受体蛋白分子,试验分别无菌取14,16,18日龄鸡胚肠组织,用300 U/m LⅪ型胶原酶和0.1 mg/m LⅠ型中性蛋白酶混合搅拌消化25 min,用壁差法纯化鸡肠上皮细胞,贴壁时间差为3 h,分别种植于20%FBS包被过的和未包被过的一次性塑料细胞培养瓶中,在倒置显微镜下观察细胞生长状态,透射电镜下对培养细胞进行鉴定。结果表明:采用16日龄鸡胚肠组织用Ⅺ型胶原酶和Ⅰ型中性蛋白酶联合消化25 min,可获得较多的肠隐窝单位,肠上皮细胞在20%FBS包被过的一次性细胞培养瓶中贴壁效果良好,细胞生长状态良好;透射电镜下可见鸡肠上皮细胞的微绒毛,鉴定为鸡肠上皮细胞。     

一株鸡源志贺氏菌的分离、鉴定及耐药性分析

为了对鸡源志贺氏菌性腹泻进行快速准确的诊断和耐药性研究,试验对由贵州省动物疫病研究室提供的一株鸡源志贺氏菌进行进一步的分离、PCR鉴定及药敏试验。结果显示,经细菌分离培养、革兰氏染色及生化鉴定试验,该菌符合志贺氏菌的特点及其生化特性;PCR检测结果显示,针对志贺氏菌ipa H基因设计的一对引物可扩增出393 bp的目的条带,与预期大小一致,具有高度的特异性;对其耐药性的研究显示,该株志贺氏菌对参试的20种药物产生不同程度的耐药性。研究鸡源志贺氏菌的分离与鉴定中所结合的PCR方法具有快速、简单、特异性强的特点,能够迅速确定病原菌,并在药敏试验中发现了针对该菌敏感性较高、疗效更好的药物。结果为鸡源志贺氏菌耐药性的有关研究与临床用药提供了科学的参考依据。     

牛种布氏杆菌82/45菌种细胞膜蛋白组分的提取

本文着重介绍了提取牛种布氏杆菌82/45菌种细菌膜蛋白组分的一种方法:菌细胞经超声波粉碎,再生后以溶菌酶和无离子表面活性剂(去氧胆酸)处理,用 SDS-PAGE 将其不溶性产物中的组分蛋白泳动分离开,切取组分蛋白条带,用圆盘电泳装置分别收集不同区段的组分蛋白。用 SDS-PAGE 鉴定蛋白纯度,取经转移吸印电泳证实对商品单克隆抗体 BR_(25)要特异反应的组分9作为抗原.通过间接 ELISA 检测证明抗原反应性良好.     

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.