乌鳢源维氏气单胞菌胞外产物的生物学活性分析

为研究维氏气单胞菌胞外产物在乌鳢感染中的致病作用以及维氏气单胞菌的致病机理,以乌鳢源维氏气单胞菌WL161为研究对象,提取其胞外产物,采用打孔法测定其胞外产物的酶活性,并对与毒力密切相关的溶血活性进行进一步的溶血谱研究,同时分析其致病性。应用LCMSMS方法对其胞外产物蛋白成分进行鉴定,利用Gene Ontology(GO)对已鉴定蛋白进行生物学过程、分子功能和细胞组分的分类分析。结果表明,WL161菌株具有淀粉酶活性、脂肪酶活性、蛋白酶活性和溶血活性,不具有明胶酶活性;ECP对其他多种动物红细胞均有溶血活性,对鱼类红细胞溶血性较强,但对鸡红细胞无溶血活性。其胞外产物共检测出118种蛋白,共参与40种生物学过程,主要涉及碳水化合物代谢过程、几丁质分解代谢过程、DNA结合等;69种分子功能主要涉及ATP结合、金属离子结合、碳水化合物结合等;19种细胞组分主要包括胞外区、细胞质、细胞外膜等。     

迟缓爱德华菌胞外产物的致病性及生物活性分析

以迟缓爱德华菌(E.tarda)胞外产物(ECP)为研究对象,通过饱和硫酸铵法从E.tarda培养上清中纯化得到其ECP,利用动物模型分析其致病性,并通过细胞试验证实了该产物对巨噬细胞功能影响,进一步测定其ECP的酶活性,并利用LC-MSMS方法分析E.tarda ECP蛋白成分。结果表明:迟E.tarda ECP对斑马鱼具有致病性,其具有淀粉酶、脂肪酶、卵磷脂酶活性和溶血活性可能在这一过程中发挥关键作用。除此之外,E.tarda ECP还能够显著增强巨噬细胞吞噬细菌活性的能力。LC-MSMS分析鉴定所提纯的ECP含有110种蛋白成分,涉及多种酶类、细胞结构蛋白和功能性蛋白。本研究为揭示E.tarda致病机理,研制新型疫苗奠定了基础。     

青虾源维氏气单胞菌胞外产物生物学特性及蛋白成分分析

为了研究维氏气单胞菌胞外产物在青虾感染中的致病作用以及维氏气单胞菌的致病机理,本试验以青虾源维氏气单胞菌QXF0711B为研究对象,提取其胞外产物,采用打孔法测定其胞外产物的酶活性,并对溶血活性进行溶血谱分析,同时分析其致病性。应用液相质谱与串联质谱相结合方法(LC-MSMS)对其胞外产物蛋白成分进行鉴定,利用Gene Ontology(GO)对已鉴定蛋白进行生物学过程、分子功能和细胞组分的分类分析。结果表明:QXF0711B菌株胞外产物具有淀粉酶活性、脂肪酶活性、蛋白酶活性和溶血活性,不具有明胶酶活性;其可溶解多种动物红细胞,尤以对鱼类红细胞溶血性更强,但对鸡、鸭红细胞无溶血活性。通过对菌株胞外产物蛋白成分分析显示有90种蛋白:共参与45种生物学过程,主要涉及碳水化合物代谢过程、运输等;共有46种分子功能,主要涉及DNA结合、ATP结合、金属离子结合等;为12种细胞组分,主要包括膜的有机组成、细胞质、细胞外膜等。     

大菱鲆源美人鱼发光杆菌胞外产物生物学特性及蛋白成分分析

为了研究美人鱼发光杆菌胞外产物对大菱鲆的致病作用以及美人鱼发光杆菌的致病机理,本试验以大菱鲆源美人鱼发光杆菌为研究对象,提取其胞外产物,采用打孔法测定其胞外产物的酶活性,并对溶血活性进行溶血谱分析,同时分析其致病性。应用LC-MSMS方法对其胞外产物蛋白成分进行鉴定,利用Gene Ontology(GO)对已鉴定蛋白进行生物学过程、分子功能和细胞组分的分类分析。结果表明:美人鱼发光杆菌胞外产物具有淀粉酶活性、脂肪酶活性、蛋白酶活性、卵磷脂酶活性和溶血活性,不具有明胶酶活性和脂肪酶活性;其可溶解多种动物红细胞,尤以对鱼类红细胞溶血性更强,但对鸡、鸭红细胞无溶血活性。通过对菌株胞外产物蛋白成分分析显示,有45种蛋白共参与34种生物学过程,主要涉及碳水化合物代谢过程、运输等;共有41种分子功能,主要涉及脱氢酶、磷酸酶、氧化还原酶和金属离子结合等;包括15种细胞组分,主要有细胞质和细胞外膜等。     

病原菌致病性胞外产物(ECP)的研究进展

许多病原菌能分泌多种胞外产物,如蛋白酶、磷脂酶、脂肪酶、明胶酶及溶血素等。微生物分泌的明胶酶、蛋白酶、淀粉酶、磷脂酶属于胞外酶,在细菌致病中可以和溶血毒素一起进行协同作用,分解破坏宿主组织成分。笔者综述了病原菌的致病性胞外产物,以及研究胞外产物的方法。     

致水貂出血性肺炎铜绿假单胞菌胞外产物生物活性及免疫保护力分析

胞外产物在细菌致病过程中发挥重要作用,为探索胞外产物在铜绿假单胞菌致病过程中的作用,首先从铜绿假单胞菌培养液提取其出其胞外产物,利用小鼠模型分析其致病性,并通过细胞证实了该产物对巨噬细胞功能的抑制作用,进一步测定其胞外产物的酶活性并利用LC-MSMS方法对铜绿假单胞菌胞外产物蛋白成分和功能进行分析。结果表明,铜绿假单胞菌胞外产物对小鼠有致病性,能够显著抑制巨噬细胞吞噬细菌活性,其具有淀粉酶、脂肪酶、蛋白酶、卵磷脂酶活性和溶血活性可能在这一过程中发挥关键作用。LC-MSMS分析鉴定所提纯的胞外产物中有153种蛋白成分,涉及多种酶类、细胞结构蛋白和功能性蛋白。用低剂量胞外产物免疫动物对于铜绿假单胞菌感染具有较明显的保护率,可达90%。本试验为揭示铜绿假单胞菌致病机理,研制新型疫苗奠定基础。     

南四湖河蟹养殖区气单胞菌的分离鉴定及胞外酶分析

细菌分泌的明胶酶、蛋白酶、淀粉酶、磷脂酶等均属于胞外酶,在细菌致病机理中可以和溶血毒素一起进行协同作用,分解并破坏宿主组织成分,对河蟹的生长不利。为了研究南四湖河蟹养殖区水体中气单胞菌胞外产酶的情况,对该养殖区的水体微生物进行了初步筛选和分离,得到了气单胞菌菌株。该菌产胞外酪蛋白酶、淀粉酶、磷脂酶、明胶酶和溶血素,不产胞外脲酶。     

嗜水气单胞菌胞外产物的生物活性及主要蛋白型分析

在血清学分型的基础上制备了23 株嗜水气单胞菌和1 株温和气单胞菌的胞外产物。分析这些菌株的溶血活性、蛋白酶解活性和细胞毒活性。结果表明,上述3 种生物学活性与菌株血清型间没有严格的对应关系。SDS PAGE分析显示,胞外产物的SDS PAGE图谱主要包括35 ku,45 ku,53 ku 3个主要蛋白质条带。有别于此前的多数报道,35 ku的蛋白质条带为多数菌株(22/24)所共有。根据凝胶上主要蛋白条带在不同菌株中的分布,可初步将其中的18 株细菌分为3 个胞外产物ECPs蛋白型,该ECPs蛋白型显示与血清型有一定的对应关系。经蛋白酶K消化处理的ECPs,银染可见脂多糖(LPSs)的典型O 糖侧链结构,显示脂多糖是组成粗制ECPs的重要组分之一。     

溶藻弧菌胞外产物对大黄鱼的致病性

采用杯碟法测定了由网箱养殖濒死大黄鱼体内分离的溶藻弧菌胞外产物的成分及酶活性 ,并用胞外产物粗提液对大黄鱼进行致死试验 ,电镜观察了致死大黄鱼肝、肾、脾等组织的细胞病变。结果表明 ,溶藻弧菌胞外产物具有明胶酶、淀粉酶、酪蛋白酶、脂肪酶、卵磷酯酶、几丁质酶以及溶血活性 ,该胞外产物对大黄鱼具有明显的致死作用 ,可造成大黄鱼肝、肾、脾等组织严重病变     

大鲵肺炎克雷伯菌的部分生物学特性与致病性分析

为确定从患病大鲵分离鉴定到的肺炎克雷伯菌的生物学特性及其对大鲵的致病性,本研究采用比色法和平板扩散法对肺炎克雷伯菌的生长条件及胞外产物进行研究,并对人工感染该菌的大鲵主要靶器官进行组织病理学分析。结果表明:肺炎克雷伯菌最适宜在37℃、pH7.5和1.0%NaCl浓度的条件下生长;其胞外产物具有脂肪酶、蛋白酶、卵磷脂酶活性,无淀粉酶、明胶酶、脲酶及溶血活性;感染该菌后大鲵各器官均表现出不同程度的炎性反应,其中以肝炎和坏死性脾炎最为明显。本研究确定了肺炎克雷伯菌的最适生长条件,分析了其胞外产物主要成分,并对其感染大鲵后主要靶器官的组织病理变化进行了探究,为该菌的有效防控与致病机理的研究奠定了基础。     

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.