孕马血清促性腺激素的提纯研究

以比活100 IU/mL以上的孕马和孕驴血清为原料,应用HPO2沉淀-超滤浓缩(或用聚 乙二醇浓缩)-乙醇分部沉淀-超滤截留-SE-SephadexC-50柱层析-羟基磷灰石柱层析,进 行PMSG提纯试验,获得了比活9 000 IU/mg左右的高纯度产品,经PAG圆盘电泳只出现一条带.     

FQS-11O对雏鸡人工感染鸡大肠杆菌的保护试验

用 FQS- 110对雏鸡人工感染鸡大肠杆菌进行了保护试验。于感染后 1、6、12、2 4 h给药 ,0 .335mg/ kg为 10 0 %保护率最小剂量 ,0 .16 0 mg/ kg的保护率为 90 %、0 .12 2 mg/ kg的保护率为50 %、0 .0 75mg/ kg的保护率为 10 %。经统计 ,ED50 95%可信限为 (0 .111± 0 .0 19) mg/ kg。试验结果提示 FQS- 110对雏鸡人工感染鸡大肠杆菌病有保护作用。     

富硒乳酸粪肠球菌微胶囊包埋工艺及产品抗性试验研究

对富硒乳酸粪肠球菌采用0.03%к-卡拉胶、0.25%刺槐豆胶和2.5%明胶喷雾干燥的方法,进行三层微胶囊生物包埋,获得产品率为82.68%,包埋后菌体存活率为72.15%,菌体硒含量为0.571 mg/g.产品抗性试验表明:在人工胃酸 (pH2.1) 环境下,经2h包埋的乳酸肠粪球菌的存活率达96%以上,不受胃酸的影响;耐贮存性试验证明,包埋的富硒乳酸肠粪球菌在常温下贮存1年,由初始的5.7×108cfu/ml活菌数降为5.4×107cfu/ml,菌体存活率保持在19.5%以上,包埋菌体的耐贮存性能好;在一定加热条件下,50℃、30min菌体存活率为89.71%,100℃、5min为86.91%,120℃、2min为89.18%,证明经3层微胶囊包埋的富硒乳酸粪肠球菌,其微胶囊产品的耐热稳定性好.     

蜂胶对鸡副嗜血杆菌的抑菌效果试验

蜂胶是一种具有广谱生物学活性的天然物质,具有抗菌、抗病毒、抗肿瘤、消炎、增强机体免疫功能和促进组织再生等作用,本文就其对鸡副嗜血杆菌的抑菌作用进行了试验.结果表明,终浓度为1mg/ml-5mg/ml的蜂胶乙醇浸出物对试验菌株具有完全抑制作用,终浓度为0.5mg/ml和0.1mg/ml的蜂胶乙醇浸出物对试验菌株具有部分抑制作用,终浓度为0.01mg/ml的蜂胶乙醇浸出物对试验菌株没有抑制作用.     

猪流行性腹泻病毒SDbz株的分离与鉴定

病料应用套式RT-PCR检测呈现PEDV阳性,经处理将其接种到含终质量浓度50 mg/L胰酶的Vero细胞上进行病毒分离传代,盲传到10代左右开始出现局灶性CPE,20代以后特征性CPE稳定出现.将病毒Vero细胞培养物应用毒价测定及病毒中和试验、套式RT-PCR和间接免疫荧光进行检测鉴定,证明所分离到的病毒为PEDV,并将其命名为PEDV SDbz株.     

喹赛多对山羊生长性能及胴体品质的影响

60只3月龄左右杂交山羊,随机分为6组,空白对照组饲料不添加任何药物,药物对照组饲料添加50 mg/kg喹乙醇,4个试验组饲料中分别添加25、50、150和250 mg/kg喹赛多,试验期90 d.结果表明喹赛多25、50和150mg/kg能改善山羊平均日增重(ADG)4.4%、14.5%和7.2%,提高饲料转化率(FCR)5.9%、12.0%和7.4%.喹赛多250 mg/kg提高FCR 8.6%,但降低ADG 2.1%.喹赛多50 mg/kg组ADG和FCR均高于喹乙醇组.喹赛多50 mg/kg降低山羊腹泻频率39.0%,但随剂量增加,其抗腹泻作用下降.喹赛多25、50、150和250 mg/kg能提高山羊屠宰率2.5%、9.0%、5.0%和1.0%,增加眼肌面积4.8%、34.1%、16.1%和14.0%.喹赛多50 mg/kg组山羊净肉率提高14.0%,高于其他各组.喹赛多各剂量均能显著增高肌肉pH值,平均降低滴水损失值13.7%.可见,喹赛多适宜剂量,尤其50 mg/kg,有较好的促进山羊生长和改善胴体品质的作用.     

硫酸粘菌素预混剂对仔猪人工诱发大肠杆菌病的疗效试验

50头16日龄三元杂交猪经口一次人工感染大肠杆菌O8:K88强毒标准株,诱发仔猪大肠杆菌病(白痢)模型,分别用(10%)硫酸粘菌素预混剂800mg/kg、400mg/kg、200mg/kg口服治疗.结果显示:硫酸粘杆菌素预混剂高剂量组的死亡率、有效率、治愈率和相对增重率为0%、100‰90%和92.45%,中剂量组为10%、90%、80%和96.32%,两者差异不显著,但均极显著优于低剂量组.说明(10%)硫酸粘菌素预混剂口服时人工诱发仔猪大肠杆菌病有较好的疗效,应用时以400mg/kg为宜,重症加倍.     

相思子毒素-a的纯化及鉴定

采用硫酸铵分级分离法和凝胶层析法,从相思子种仁中分离纯化出一种毒蛋白P1′。凝胶薄层扫描测得纯度≥97%;SDS-PAGE电泳测定其相对分子质量为64300;经β-巯基乙醇处理,P1′分离为A、B 2条链,相对分子质量分别为29100和35400;经腹腔注射,小鼠LD50为2.11μg/kg;P1′质量浓度≥3.91 mg/L时,可凝集兔红细胞;P1′的B链N末端8个氨基酸序列为：I-V-E-K-S-I/L-I-N,与相思子毒素-a（abrin-a）和相思子毒素-b（abrin-b）同源性较高,为75%;肽质量指纹谱（PMF）分析表明,P1′与abrin-a匹配强度最高,为86%,与abrin-b、相思子毒素-c（abrin-c）和相思子毒素-d（abrin-d）匹配强度均为10%,表明毒蛋白P1′为abrin-a。abrin-a经1%甲醛减毒处理制备类毒素,家兔5次免疫后获得了效价高、特异性较强的抗血清。     

康氏木霉诱变前后纤维素酶组分的分离提纯

康氏木霉NN-15B_7株是康氏木霉854-B_2株经多次理化因素诱变,最后搭载卫星在太空条件作用下筛选出来的变异株.为比较诱变前后两个菌株所产纤维素酶的异同,本实验采用系列分离的方法,首先对其酶组分进行了分离提纯.粗酶粉经Scphadex G75凝胶过滤、DEAE-Scphadex A50离子交换层析和SP-Scphadex C50离子交换层析,分离得到了纯的C_1酶和Cx酶.经鉴定,C_1酶中含有微量Cx酶活力,PAG圆盘电泳只显示1条区带;Cx酶中均测不出C_1酶和β—葡萄糖苷酶活力,PAG圆盘电泳显示4条区带.诱变前后两株纤维素酶的组分分布未见差异.     

青海省果洛藏獒血液乳酸脱氢酶同工酶酶谱的研究

采用聚丙烯酰胺凝胶垂直平板电泳法对青海省果洛州39只藏獒的血清乳酸脱氢酶(SLDH)和红细胞乳酸脱氢酶(RBC-LDH)同工酶酶谱及其多态性进行了研究。结果发现:1)被检藏獒的S-LDH经电泳可分离出S-LDH1、S-LDH2、S-LDH3、S-LDH4和S-LDH5等5条区带,呈现出S-LDH1A(20.51%)和S-LDH1a(79.49%)两种电泳表型而表现出多态性;2)RBC-LDH经电泳可分离出RBC-LDH1、RBC-LDH2和RBC-LDH3等3条区带,呈现出RBC-LDH2A(43.24%)和RBC-LDH2a(56.76%)两种电泳表型;3)S-LDH同工酶5条区带的相对电泳迁移率分别为53.0%、40.8%、25.5%、9.5%和3.8%。     

SP-SephadexC-50柱层析法纯化孕马血清促性腺激素(PMSG)

应用HPO_3沉淀-硫酸铵浓缩-乙醇分部沉淀法,从孕马血清中粗提PMRG(平均比活1026IU/mg.平均回收率75%),用SP-Scphadex C-50一次柱层析纯化PMSG粗品,获得平均比活11847IU/mg的高活性PMSG精品,对粗品的平均回收率为88.5%.     

重组猪IFN-α原核表达及其活性分析

为了表达猪重组α干扰素(rIFN-α)并对它的生物学特性进行研究,本研究采用RT-PCR从猪脾淋巴细胞中扩增出猪IFN-α基因,以pPROExHTa为载体构建了表达重组质粒polFN-α,转化宿主菌BL21,经IPTG诱导猪rIFN-α获得了表达,其分子量约22 ku.该重组蛋白以包涵体形式存在,其表达量占总菌体蛋白7%.粟用Ni-Ni金属螯合亲和层析方法纯化,其纯度达到80%以上,包涵体经复性后,在WISH/VSV系统上,采用细胞病变抑制法测定表明,其稀释度在小于1:103时才有抗病毒活性.本实验表达的猪rIFN-α具有一定的抗病毒活性,为研究具有广谱抗病毒效应的猪干扰素具有重要意义.     

鸭肠炎病毒NP蛋白的原核表达及间接ELISA方法的建立

设计一对特异性引物扩增出鸭肠炎病毒(DEV)核衣壳蛋白(NP)基因,并将其定向插入到原核表达载体pET32a上,构建了NP基因的原核表达载体pET-NP;将重组载体pET-NP转化表达宿主菌BL21后,经SDS-PAGE分离后行Western blot显示,获得的表达产物具有良好的免疫原性;应用His.Bind亲和层析柱纯化重组NP蛋白,并以此作为包被抗原,初步建立了检测鸭肠炎病毒抗体的iNP-ELISA;经方阵滴定确定,重组蛋白抗原的最佳包被浓度为5.0μg/L,血清最佳稀释度为1∶80,阳性判定标准为:待检血清OD405值≥1.2,且待检血清OD405和阴性血清OD405的比值≥2.0;应用iNP-ELISA对450份鸭血清样本进行检测,结果iNP-ELISA与全病毒包被的iDEV-ELISA符合率达90.9%。     

Purification of the third component of canine complement

A rapid, simple procedure has been developed for the purification of the third component (C3) of canine complement. Dog plasma was initially fractionated by precipitation with 4% (w/v) polyethylene glycol (PEG) 4000. The supernatant was depleted of plasminogen using a Sepharose 4B-lysine column, and the effluent was again fractionated with PEG 4000 at 16% (w/v). The precipitate was resuspended and passed over a DEAE-Sephacel column. The fractions containing hemolytically active C3 were pooled, concentrated, and passed over a CM-Sepharose CL-6B column to yield the final purified product. Rabbit anti-whole dog serum identified only one protein in the purified material on immunoelectrophoresis. When injected into a rabbit, the purified product raised an antisera which reacted with only one protein in both whole dog serum and the purified product. Analysis by SDS-PAGE revealed a single band of MW 179,000 +/- 7,000 (+/- 1 S.D.) daltons which, upon reduction with 2-mercaptoethanol, resulted in 2 bands of 114,000 +/- 6,000 daltons and 65,000 +/- 3,500 daltons. Final recovery was 18% with respect to C3 antigen and 9% with respect to C3 hemolytic activity.     

Isolation and partial characterization of prolactin from equine pituitary gland (hypophysis)

Highly purified equine prolactin was prepared from equine pituitary glands (hypophysis) by serial extractions with water at pH 5.5, 0.1 M (NH4)2SO4 at pH 4.0, and 0.25 M (NH4)2SO4 at pH 5.5 to remove other hormones, and then finally with 70% ethanol at pH 9.3 to 10.0 to extract prolactin. Preliminary purification of the extract involved salting out other substances with 0.1% NaCl at pH 9.0. Prolactin was precipitated out by adding three times the volume of 95% ethanol at 4 C. This prolactin preparation had a biological potency of 24 IU/mg. Further purification by isoelectric focusing on a pH gradient of 5 to 7 gave three prolactin components with the following characteristics: isoelectric point 5.8, 5.7, and 5.25; biological potencies (IU/mg) 35.6, 19.6, and 11.3. The major component had a molecular weight of 25,000, an isoelectric point of 5.8, and a biological potency of 35.6 IU/mg. Antiserum produced against this component did not cross-react with equine follicular stimulating hormone, luteinizing hormone, and growth hormone, but did cross-react with ovine and bovine prolactin. Human and murine prolactin had little cross-reactivity with the equine prolactin antiserum.     

Receptor-specific binding of purified F4 to isolated villi.

Different procedures for preparing and purifying F4ac fimbriae of the enterotoxigenic Escherichia coli strain GIS 26 (O149:K91:F4ac LT+Sta+STb+) were performed and the purity and yield of F4ac were compared. Fimbriae were prepared by either mechanical shearing or heatshock treatment of concentrated bacterial suspensions (10(11) bacteria/ml). The mechanical shearing procedure resulted in approximately 1.7 mg fimbriae (i.e. 74.4% of the isolated protein) and 0.6 mg (25.6%) contaminating proteins per 10(12) bacteria, whereas the yield of fimbriae following heatshock treatment was lower (0.3 mg per 10(12) bacteria, i.e. 26.2%) and the relative contamination higher (1.0 mg per 10(12) bacteria, i.e. 73.8%). A further purification consisted of either anion exchange chromatography (AEC) or electro-elution from SDS-polyacrylamide gels. The electroelution procedure was performed under reducing and denaturing conditions, so that purified FaeG subunits, the major subunit of F4, were finally obtained. The binding activity of fimbriae, nonpurified as well as purified, and FaeG to F4-specific receptors on isolated intestinal villi was assessed in an inhibition adhesion assay. Native fimbriae as well as major subunits were able to bind to the receptors, and the specificity of the binding was demonstrated by blockage with F4ac-specific MAb.     

Attempts at biotechnical induction of puberty in young female pigs. 2. Effects of various time intervals between one puberty induction with PMS and HCG to the following estrus synchronization on estrus and ovulation in animals about 190 days old

A biological engineering approach to induce puberty in 125 young female fattening pigs aged 190 days was undertaken on the basis of a mixture of 500 IU PMS (Prolosanserum, Dessau) with 250 IU HCG (Gonabion, Dresden). The injections were made subcutaneously. Pronounced oestrus symptoms were recorded from the external genital organs of 80% of the probands up to ten days after injection, associated with toleration in 52.8% of them. Toleration usually started on the fourth to sixth days after injection. Cycles began to develop in 57.1% up to the next oestrus period. Animals with -/x weight increase per die of 400 g exhibited lower responses. Results in terms of heat and ovulation were lower along with shorter intervals, when oestric synchronisation was undertaken 53, 32, and 17 days after the induction of puberty (20 days Suisynchron, Bernburg; 750 IU PMS).     

重组人γ－干扰素纯化工艺的建立

采用超声破碎的方法提取hIFN-γ包涵体,经盐酸胍溶解、稀释复性、浓缩后通过SPSepharose F.F层析纯化,简化了纯化步骤,缩短周期,提高了蛋白回收率。SDS-PAGE检测表明,hIFN-γ纯度达97%,比活性为3.5×107IU/mg,总回收率达40%。说明整个工艺适合于大规模生产的要求,具有实际应用价值,为hIFN-γ批量生产奠定了良好的基础。     

果子狸的人工催情和年产双胎试验

肌注ＰＭＳＧ＋ＣＨＧ、ＬＲＨ－Ａ或ＦＳＨ＋ＬＨ，能促使母果子狸发情、交配和产仔。ＰＭＳＧ５００ＩＵ＋ＨＣＧ２５０ＩＵ，ＬＲＨ－Ａ５０－１００μｇＦＳＨ１６０ＩＵ＋ＬＨ１００ＩＵ时催情效果较佳。使用上述药物，在每年１月３０日在若进行第１次催情，果子狸可比自然状态提早约１个月于４月５日前后产下第１胎仔狸。仔狸２０日龄断奶成活率较高。断奶后第１５ｄ对母猪第２次催情，７月中旬前后可产下第２胎仔狸，做到在较