IL-17单克隆抗体的制备与鉴定

为制备山羊IL-17单克隆抗体,诱导重组菌rIL-17-pET32a-TransB(DE3)表达山羊IL-17重组蛋白(rIL-17),纯化后免疫BALB/c小鼠,取免疫合格的小鼠脾细胞与SP2/0骨髓瘤细胞进行细胞融合,采用间接ELISA方法筛选阳性克隆细胞株。对获得的杂交瘤细胞进行染色体组型分析,并对其分泌的IL-17单克隆抗体进行抗体特异性、抗体类别等分析。结果显示,成功获得了纯化的山羊IL-17原核表达产物;筛选到1株能特异性分泌山羊IL-17单克隆抗体的杂交瘤细胞株-B6,其分泌的单克隆抗体亚型为IgG1,抗体轻链为κ。     

达氟沙星单克隆抗体的制备与鉴定

采用碳二亚胺法将达氟沙星与BSA和OVA偶联制成免疫抗原DFLX-BSA、检测抗原DFLX-OVA。采用FeCl3显色反应、紫外扫描分析法对合成的抗原进行了鉴定。用免疫抗原DFLX-BSA腹腔免疫BALB/c小鼠,有限稀释法筛选获得分泌特异性抗体的杂交瘤细胞株1株4F9,单抗亚型鉴定为IgG1,并将此细胞株注射小鼠腹腔获得腹水,用辛酸-硫酸铵法对腹水进行了纯化。纯化后的抗体效价为2.48×10-6,紫外分析方法计算蛋白含量为1.348 mg/mL。     

恩诺沙星单克隆抗体的制备及其鉴定

采用碳二亚胺法和氯甲酸异丁酯法合成恩诺沙星的人工抗原,结合比为15∶1。用人工抗原腹腔免疫BALB/c小鼠,有限稀释法筛选获得分泌特异性抗体的杂交瘤细胞株2H10C2F11,并将该细胞株注射小鼠腹腔获得腹水。纯化后的抗体效价为3.96×10-6,紫外分析方法计算蛋白含量为1.139 mg/mL,琼脂双扩实验表明抗体为IgG1型,SDS-PAGE电泳图谱显示纯化效果理想;经间接ELISA方法测定,抗体的亲和力为1.8×108L/moL。     

牛初乳免疫球蛋白IgG单克隆抗体的制备

为了制备牛初乳免疫球蛋白IgG单克隆抗体,试验利用标准IgG蛋白作为免疫原,免疫6周龄Balb/c雌性小鼠,运用淋巴细胞杂交瘤技术,通过间接ELISA法筛选,采用有限稀释法,经过3次克隆筛选,获得2株稳定分泌抗IgG蛋白的杂交瘤细胞株,分别命名为E7和D9,并进行了亚类鉴定.结果表明:该杂交瘤细胞培养上清液抗体效价抗体...     

2—C—7单克隆抗体对伊氏锥虫感染力的影响

2-C-7杂交瘤细胞株对伊氏锥虫有着专一反应性。为了探讨该杂交瘤细胞株所分泌的抗伊氏锥虫单克隆抗体的生物学活性,我们观察了用单抗处理过的伊氏锥虫对小白鼠的感染力。一、材料与方法 1.杂交瘤细胞培养上清液的收集及其抗体滴度的测定复苏2-C-7细胞株并培养、收集其上清液。用ELISA法测定其抗体阳性滴度,OD值为0.87,阴性对照OD值为0.04。     

猪带绦虫六钩蚴45W-4BX抗原的制备及其杂交瘤细胞株的建立

为获得针对猪带绦虫六钩蚴（TSO）45W-4BX抗原的杂交瘤细胞株,用IPTG对TS045W-4BX的重组质粒pGEX-4BX进行了诱导表达,并采用Sepharose-4B层析技术对表达产物进行纯化,运用SDS—PAGE和Western—blot分别对其纯度和活性进行了检测。分别用弗氏完全佐剂、弗氏不完全佐剂乳化已纯化的猪带绦虫TS045W-4BX重组抗原,随后用其分别免疫BALB／c小鼠3次,检测血清抗体效价呈阳性。之后,再进行加强免疫,取免疫小鼠脾细胞和SP2／0细胞进行融合,经TS045W-4BX抗原和GST抗原双系统间接ELISA筛选,最终获得了18株抗TS045W-4BX抗原的杂交瘤细胞株。采用有限稀释法对其中的4株进行5次亚克隆,最终获取了4株稳定分泌针对TS045W-4BX抗原的单克隆抗体的杂交瘤细胞株,金标试纸条法鉴定其抗体亚类均属于IgG1类,轻链为κ型。     

1株抗欧洲型和美洲型PRRSV核衣壳蛋白单克隆抗体的制备与鉴定

利用RT-PCR方法扩增出欧洲型猪繁殖与呼吸综合征病毒(PRRSV)SS-6毒株的核衣壳(N)蛋白基因,将其克隆到原核表达载体pGEX-6p-1上,构建了重组表达质粒pGEX-N,并将其转化到大肠杆菌BL21中,在诱导剂IPTG的诱导下获得高效表达,重组蛋白的分子量约为40 ku。用纯化的重组N蛋白免疫Balb/c小鼠,采用杂交瘤技术制备抗PRRSV N蛋白的单克隆抗体。经细胞融合获得一株可稳定分泌特异性单抗的杂交瘤细胞株,命名为1 B6,将其连续培养20代后仍能稳定分泌抗体。亚型鉴定结果为IgG1型,其轻链为κ链;间接免疫荧光试验和免疫印迹试验均证明,1B6单抗既能与欧洲型PRRSV反应,也能与美洲型PRRSV反应;ELISA检测杂交瘤细胞培养上清抗体效价为1:640,腹水的效价为1:256 000,为猪繁殖与呼吸综合征的诊断奠定了基础。     

猪流行性腹泻病毒N蛋白的原核表达及其单克隆抗体的制备

本研究旨在采用原核表达系统表达猪流行性腹泻病毒(PEDV)的核衣壳蛋白(N),并进一步制备其单克隆抗体。将构建重组原核表达质粒pET28a-N转化大肠杆菌BL21(DE3)感受态细胞,经IPTG诱导表达重组蛋白,并采用Ni-NTA亲和层析和分子筛进行纯化。将纯化后的重组N蛋白免疫BALB/c小鼠,取小鼠脾脏B淋巴细胞与SP2/0瘤细胞融合,采用间接ELISA方法筛选阳性杂交瘤细胞株,并对其分泌抗体的特性进行了分析。结果显示:重组质粒pET28a-N在E.coli BL21中高效表达,筛选获得了2株稳定分泌抗N蛋白单克隆抗体的杂交瘤细胞株1A3和4F6,其分泌的抗体均为IgG1亚型,腹水效价分别为5.12×10~5、1.28×10~5。本研究为进一步研究N蛋白的功能以及建立PEDV免疫学诊断方法奠定了基础。     

鸡CD4基因片段原核表达及其单抗制备

将PCR扩增的鸡CD4基因片段克隆到pET-32a原核表达载体,构建获得原核表达重组载体pET-32a-CD4.重组载体导入大肠杆菌BL21(DE3),经过IPTG诱导表达,Ni-NTA亲和树脂纯化获得融合蛋白His-CD4.以此融合蛋白为抗原免疫BALB/c小鼠,用杂交瘤细胞技术制备了1株能够稳定传代并分泌抗CD4多肽单抗的杂交瘤细胞株,命名为3E12.经检测该抗体亚类为IgG2b,单抗腹水的间接ELISA效价为1:105,Western blot结果显示单抗与CD4多肽能特异性地结合.     

非洲猪瘟病毒p72蛋白原核表达及单克隆抗体制备

【目的】表达与纯化非洲猪瘟病毒(African swine fever virus, ASFV)p72蛋白,并制备其单克隆抗体。【方法】构建原核表达载体pET-28b-p72,转化大肠杆菌BL21(DE3)感受态细胞并进行诱导表达和蛋白纯化;用纯化后的p72蛋白免疫BALB/c小鼠,将免疫小鼠的脾细胞与骨髓瘤细胞进行细胞融合并制备单克隆抗体,通过间接ELISA法和亚克隆筛选出分泌抗体的阳性杂交瘤细胞;通过小鼠抗体类型检测试剂盒检测抗体类型;通过体内诱生法制备抗ASFV p72蛋白的单克隆抗体腹水,使用饱和硫酸铵沉淀法进行抗体纯化,通过间接ELISA法、间接免疫荧光试验(IFA)和Western blotting检测单克隆抗体效价和特异性。【结果】ASFV p72重组蛋白在大肠杆菌中以包涵体形式表达,将纯化的p72蛋白制备单克隆抗体,获得4株分泌IgG1抗体的单克隆细胞株,分别命名为6F8、7C3、8H7和9G2。间接ELISA结果显示,6F8与8H7细胞株分泌的抗体效价均为1∶64 00,7C3与9G2细胞株的抗体效价均为1∶12 800,且4株细胞株分泌的抗体与p72蛋白反应结果均呈...     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein     

Evaluation of the Microbiological Status of Milk and Various Structures in Mammary Glands from Naturally Infected Dairy Cows

A knowledge of the microbiological status of milk and of the different structures in the mammary glands has great importance in elucidating the pathogenesis of mammary gland infections. The objective of this study was to evaluate the microbiological status of various structures in the mammary glands from naturally infected dairy cows following slaughter. A total of 94 samples of milk, 184 samples of mammary parenchyma, 168 samples of gland cisterns, and 168 samples of teat cisterns were collected for microbiological examination. Microorganisms were detected in 59.9% of all samples, 67.0% of the milk samples, 70.1% of the mammary parenchymas, 55.9% of the gland cisterns and 48.8% of the teat cistern samples. When all samples were considered, coagulase-negative Staphylococcus were the most prevalent (35.7%) followed by coagulase-positive Staphylococcus (12.2%), Corynebacterium bovis (2.4%), Prototheca sp. (1.9%), and Streptococcus dysgalactiae (1.5%). There was a significantly higher occurrence of microorganisms in the milk and mammary parenchyma compared to the gland cisterns and teat cisterns. This revised version was published online in July 2006 with corrections to the Cover Date.     

Development and survival of free-living stages of gastrointestinal nematodes of sheep and goats on pasture in the Nigerian derived savanna

Four grass plots were sequentially contaminated with goat faeces containing known numbers of unembryonated eggs of predominantly Haemonchus contortus and Trichostrongylus spp. between October 1982 and April 1983. Four other plots were similarly contaminated with sheep faeces between February and May 1987. An additional plot was repeatedly contaminated with sheep faeces from February to April 1987. Populations of free-living stages in faeces and of infective larvae (L₃) in the herbage were subsequently monitored until the end of April and June of 1983 and 1987 respectively. During February and May 1987 two control cultures of sheep faeces were incubated in the laboratory at 25°C–30°C and at a constant temperature of 50°C and the free-living development was also monitored. L₃ developed very readily in the faeces cultured at 25°C–30°C and in those spread on a grass plot in October, at the end of the wet season, but developed less on the plot contaminated in May at the start of the wet season. Worm eggs in faeces deposited on plots during the hot dry season (December to April) or incubated at 50°C died and disintegrated after 24–48 h exposure to the high environmental temperatures. The results indicate that it is unlikely that gastrointestinal nematodes of sheep and goats can develop or survive on open pasture during the dry season in the Nigerian derived savanna zone.