鸡白细胞介素2分子单克隆抗体的研制

以含有鸡白细胞介素2（ChlL-2）基因的重组真核表达质粒pcDNA3．1-ChlL-2免疫6周龄BALB／c小鼠,末次加强免疫后取其脾细胞与骨髓瘤细胞Sp2／0-Ag-14融合,应用间接ELISA筛选阳性克隆。共获得2株特异性分泌抗鸡IL-2分子的杂交瘤细胞株,分别命名为1H10和1E6,其腹水ELISA效价分别为1：6400和1：3200,亚类鉴定结果均为IgM。重组质粒pcDNA3．1-ChlL-2转染COS-7细胞,以上述单克隆抗体（mAb）检测表达产物,结果表明,2株mAb均能与表达产物反应;Western blot分析结果显示,2株mAb均与原核表达鸡IL-2蛋白发生特异性反应。本研究所制备的抗鸡IL-2分子mAb可为建立简单、快速的鸡IL-2检测方法提供可能,并为鸡IL-2生物学特性和禽类细胞免疫机理的研究提供材料。     

鸭呼肠孤病毒p18重组蛋白表达、纯化及其单克隆抗体制备

研究旨在制备DRV p18蛋白单克隆抗体。试验通过原核表达并纯化DRV p18重组蛋白,经BCA蛋白浓度测定后免疫BALB/c小鼠;通过细胞融合技术制备杂交瘤细胞,获得的p18单克隆抗体通过ELISA、IFA和Western blot试验进行鉴定,并将杂交瘤细胞腹腔注射小鼠获得单抗腹水,通过Western blot试验验证其特异性。结果显示：纯化的重组p18蛋白浓度为1.37 mg/mL,经过三轮亚克隆获得4株分泌单克隆抗体的杂交瘤细胞株1E3、2C4、4A2和4D4,亚型鉴定1E3和4D4重链为IgG1型、2C4重链为IgM型、4A2为IgG2b型,轻链均为κ型;4株单克隆抗体均能使感染DRV的BHK-21细胞发出特异性荧光,并在18 ku处存在特异性条带;4D4腹水ELISA效价为1∶409 600,Western blot效价达1∶102 400,IFA效价为1∶51 200;4D4与DRV反应,而不与其他禽源常见病毒反应。研究成功制备了抗DRV p18蛋白的单克隆抗体,为进一步研探究p18蛋白的功能奠定基础。     

猪圆环病毒4型Cap蛋白单克隆抗体的制备与鉴定

为制备猪圆环病毒4型(PCV4)Cap蛋白单克隆抗体,以原核表达的重组Cap蛋白免疫6～8周龄小鼠,三次免疫后取免疫小鼠脾细胞与SP2/0骨髓瘤细胞进行融合。利用亚克隆技术和间接免疫荧光(IFA)方法筛选到2株阳性单克隆杂交瘤细胞株,分别命名为5H9和2F3。间接免疫荧光和Western blot试验表明,2株单抗均能特异性识别293T细胞中特异表达的Cap蛋白,且5H9和2F3的IFA效价分别为1∶12 800和1∶6 400。亚类鉴定结果表明,两株单抗重链均属于IgG1,轻链类型为kappa型。本研究制备的抗PCV4 Cap特异性单抗,为PCV4检测方法的建立和流行病学调查提供了有效的生物材料,也为该病毒的分离鉴定与Cap蛋白功能的探究奠定了基础。     

犬瘟热病毒F蛋白融合信号肽单克隆抗体的制备及其表位的鉴定

为制备犬瘟热病毒(CDV)F蛋白融合信号肽(FSP)的单克隆抗体(MAb)，本研究通过原核表达系统表达CDV HLJ1-13株重组FSP蛋白(rFSP)。将其免疫BALB/c小鼠，通过间接ELISA方法筛选到1株能够稳定分泌抗FSP蛋白MAb的杂交瘤细胞株G8D6E3E5，亚类鉴定结果显示该株MAb重链为Ig G2a型，轻链为κ型。构建一系列表达部分重叠的重组FSP片段，经western blot鉴定该株MAb识别的抗原区域为aa1～aa55，通过合成一系列重叠多肽，经ELISA进一步鉴定该株MAb识别的抗原表位为²¹QQHSTRSTET³⁰。采用western blot检测该株MAb与r FSP的反应原性；采用间接免疫荧光试验(IFA)检测该株MAb与天然FSP的反应原性。Western blot结果显示，CDV Snyder Hill和HLJ1-13株r FSP蛋白样品在34 ku左右均出现特异性条带；IFA结果显示，感染CDV Snyder Hill株48 h后的vero细胞出现红色荧光。以上结果表明，该株MAb既能够与原核表达的CDV...     

口蹄疫病毒非结构蛋白2C主要表位区的原核表达及其单克隆抗体的制备

本研究制备并鉴定了口蹄疫病毒非结构蛋白2C的单克隆抗体(mAb).以纯化的原核表达2C蛋白免疫BALB/c小鼠,取其脾细胞与小鼠骨髓瘤细胞融合,所获得的杂交瘤细胞经间接ELISA法筛选,有限稀释法克隆,直至所克隆的细胞能够100%的分泌抗体,用Dot-ELISA以及IFA对mAbs的特异性等进行鉴定.共获得4株抗重组蛋白2C的mAbs,其亚类鉴定结果3株为IgG1,1株为IgG2b,叠加ELISA初步判定4株单抗所识别表位相同或相近.Dot-ELISA显示这些mAbs与重组2C蛋白和(2C3AB)蛋白以及口蹄疫病毒O/China99感染的BHK-21细胞中的2C抗原均可特异性结合,IFA结果显示所得单抗能与FMDV感染细胞中的2C蛋白特异性结合.本研究获得的针对2C蛋白的特异性mAb,为进一步研究2C蛋白的结构和功能以及诊断方法奠定了基础.     

猪伪狂犬病毒gE蛋白单克隆抗体制备与鉴定

为获得猪伪狂犬病毒(PRV)gE蛋白单克隆抗体,选择原核表达的重组gE蛋白免疫6周龄BALB/c雌性小鼠,将其脾细胞与SP2/0进行融合,经间接ELISA筛选阳性杂交瘤细胞,结果获得了2株能稳定分泌抗PRV gE蛋白的杂交瘤细胞,命名为E3B8和E5C11。间接ELISA检测2株杂交瘤细胞的培养上清液抗体效价为1∶6.4×10~3,腹水的抗体效价分别达到1∶3.28×10~6和1∶6.55×10~6。2株杂交瘤细胞的染色体数分别为105和108。E3B8亚类鉴定重链为IgG1,轻链为κ链;E5C11亚类鉴定重链为IgG2b,轻链为κ链。Western blot检测显示2株单克隆抗体腹水均能与PRV重组gE蛋白发生特异性反应,间接免疫荧光试验(IFA)检测显示2株单克隆抗体均能与PRV分离毒株感染的BHK-21细胞发生特异性反应,交叉反应性检测显示2株单克隆抗体与常见病毒不发生交叉反应。表明制备的2株gE蛋白单克隆抗体效价高、特异性强,为gE蛋白结构与功能分析以及PRV免疫诊断试剂盒的开发奠定了基础。     

禽腺病毒血清4型Fiber2蛋白单克隆抗体制备及其抗原表位鉴定

旨在制备禽腺病毒血清4型（FAdV-4）纤突蛋白（Fiber2）的特异性单克隆抗体（MAb）,本研究将原核表达的可溶性重组蛋白NusA-Fiber2作为免疫原免疫BALB/c雌鼠,筛选获得3株能稳定分泌抗FAdV-4 Fiber2蛋白MAb的杂交瘤细胞株2G5、2G8、4C2,取细胞株2G5制备腹水并纯化,利用间接免疫荧光试验（immunofluorescence assay,IFA）和Western blot鉴定该单抗的特异性。用制备的单抗包被酶标板,通过一系列的优化,建立了FAdV-4 Fiber2双抗夹心ELISA检测方法。通过逐步截短分析鉴定出单克隆抗体识别的抗原表位区域。结果表明：成功获取3株单克隆细胞株2G5、2G8、4C2。MAb 2G5可与原核表达纯化的Fiber2蛋白及FAdV-4特异性反应。建立的双抗夹心ELISA检测方法具有很好的特异性、灵敏性和重复性。该MAb识别的表位序列是N端aa1—33。本研究成功制备了具有良好Western blot和IFA反应原性的单克隆抗体,为Fiber2蛋白功能研究和FAdV-4新型表位疫苗商品化研发奠定了基础。     

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.     

抗猪(嗜血)支原体MSG1蛋白单克隆抗体的制备及鉴定

以原核表达纯化的猪(嗜血)支原体MSG1蛋白免疫BALB/c小鼠,运用细胞融合技术筛选分泌针对MSG1蛋白抗体的融合细胞。通过间接ELISA方法筛选获得2株能稳定分泌抗体的融合细胞株,分别命名为1A7和3G6,Western blot结果证明这2株细胞分泌的抗体能够与重组MSG1蛋白发生特异性反应。细胞上清和腹水中的ELISA抗体效价分别为1∶4 096、1∶1 024和1∶1 638 400、1∶51 200,其单抗亚类鉴定均属于IgG1,轻链为κ型。抗原识别位点分析结果表明,2株单抗所识别的抗原位点相同。猪(嗜血)支原体MSG1蛋白特异性单克隆抗体的制备成功,为制备免疫诊断试剂盒和致病机制的研究奠定了基础。     

非洲猪瘟病毒H240R蛋白单克隆抗体的筛选与鉴定

为制备抗非洲猪瘟病毒(ASFV)H240R蛋白单克隆抗体,首先构建原核表达质粒pET-29b-H240R,再进行蛋白表达与纯化,随后免疫Balb/c小鼠,通过杂交瘤细胞技术制备、间接ELISA方法筛选获得单克隆抗体。结果显示,共获得4株杂交瘤细胞株,腹水效价均高于1∶40 000;亚型鉴定结果显示,3株单克隆抗体(12D6、21G3、8G7)重链亚类为IgG2b, 13D2重链亚类为IgG1,轻链亚类均为k。Western blot和Dot blot鉴定结果表明,21G3、13D2株单克隆抗体识别的抗原表位为线性表位,而12D6和8G7识别的是构象表位。间接免疫荧光试验(IFA)结果显示,4株单克隆抗体均能特异性识别HEK293T细胞中表达的H240R蛋白。制备了ASFV H240R蛋白单克隆抗体,为H240R蛋白的表位和功能研究奠定了基础。     

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.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

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     

Avian brood parasitism — a growing research area in behavioral ecology (part Ⅱ)

正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments in     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -