磺胺甲噁唑的控温相变免疫分析

将已制备的抗磺胺甲噁唑（SMX）单克隆抗体（AbSMX）与温度敏感水凝胶（pNIPA）偶联形成水凝胶复合物（pNIPA—AbSMX），用异硫氰基荧光素（FITC）标记的抗原（FITC-AgSMX）和游离半抗原SMX竞争地与有限量的AbSMX和pNIPA—AbSMX反应，根据水凝胶相变温度以上免疫复合物沉淀的特性进行分离，结合接原抗体免疫反应测定SMX，建立了一种检测SMX的控温相变免疫分析方法。结果表明，SMX浓度在0．1ng／mL-100μg／mL范围内有良好的线性关系，60％抑制率时灵敏度为0．03μg／mL。     

一种快速的免疫分析法测定磺胺地索辛

利用热敏感性水凝胶作为磺胺地索辛(SDM)多克隆抗体载体,通过异硫氰基荧光素(FITC)标记SDM全抗原,建立一种快速的荧光免疫分析法测定SDM。实验结果表明,该法具有较高的灵敏度,对SDM测定的线性范围在1ng/mL￣100μg/mL,60%抑制率时检出限为0.114μg/mL。     

磺胺甲噁唑抗原合成及其抗体的制备

采用重氮化法将磺胺甲噁唑(SMZ)与人血清白蛋白偶联形成免疫原,免疫大白兔制备多克隆抗体。通过紫外扫描和高效液相色谱分析偶联物,免疫抗原的偶联率为19∶1,改良辛酸-饱和硫酸铵纯化抗体,多克隆抗体效价达1∶105,间接酶联免疫吸附试验建立的SMZ检测的线性范围在0.1ng/mL~10μg/mL之间,50%抑制率检测限为22.53ng/mL,抗体与磺胺甲噁唑交叉反应率为100%,与其他7种磺胺药交叉反应率很低。表明制备的磺胺甲噁唑多克隆抗体具有很高的特异性,可用于SMZ在动物性产品中残留的检测。     

鸡肌肉组织中左氧氟沙星残留ELISA检测方法的研究

用N-羟基琥珀酰亚胺法把左氧氟沙星(LVL)与牛血清白蛋白(BSA)偶联制备免疫抗原,免疫新西兰大白兔得到LVL的多克隆抗体,建立了LVL间接竞争ELISA方法.结果表明:抗LVL血清效价达1: 212以上,得到标准曲线的线性回归方程为y=-0.289 4x+0.049 5(R2=0.987 8),50%抑制浓度(IC50)为64 ng/mL,最低检测限(LOD)为10 ng/mL,标准曲线的线性范围为10～1 000 ng/mL.批内变异系数为3.51%～7.46%,批间变异系数为8.66%～11.89%,鸡肌肉中的LVL添加浓度在10～1 000 ng/ml范围内时,回收率为73.5%～84.36%.本试验建立的ELISA方法能够满足左氧氟沙星兽药残留检测要求.     

恩诺沙星完全抗原的合成及兔源多抗血清的制备

为了合成恩诺沙星（enrofloxacin,EFLX）完全抗原,制备兔源多克隆抗体血清,试验通过活化酯法将小分子的EFLX偶联到牛血清白蛋白（BSA）和鸡卵清白蛋白(OVA)上,形成偶联物EFLX-BSA和EFLX-OVA,以EFLX-BSA为免疫原免疫兔,以EFLX-OVA为检测原通过ELISA方法检测兔血清效价。结果表明,免疫兔血清效价都在1∶51200以上,其中2号兔效价最高,达到1∶204800,敏感性好,半数抑制浓度IC₅₀为169.91 ng/mL,检测范围为37.52～302.31 ng/mL。本试验成功制备了EFLX完全抗原,获得了敏感的兔源多克隆抗体血清,为以后ELISA试剂盒和胶体金试纸条的研发奠定了基础。     

倍他米松ELISA检测方法的建立

为建立倍他米松(BET)ELISA检测方法,先使BET与琥珀酸酐反应,再采用活化酯法与牛血清白蛋白(BSA)偶联制备免疫原;其次,利用免疫动物获得多克隆抗体,经Sephrose 4B-proteinA方法对抗体进行纯化;最后,建立倍他米松ELISA检测方法。结果表明,免疫抗原偶联成功,获得了亲和力较高的多克隆抗血清,间接竞争ELISA测定其滴度为102 400、IC15为6.60×10-5 ng/mL和IC50为0.97ng/mL。该方法适用于残留在动物性食品中的BET现场大批量检测。     

恩诺沙星在鸡肉组织中残留的ELISA检测方法研究

分别用N-羟基琥珀酰亚胺法和氯甲酸异丁酯法把恩诺沙星(ENR)与载体蛋白牛血清白蛋白(BSA)和鸡卵清蛋白(OVA)偶联制备免疫抗原和包被抗原,免疫新西兰大白兔得到ENR的多克隆抗体,建立了ENR间接竞争ELISA方法。结果表明:抗ENR血清效价达达1∶212以上,得到标准曲线的线性回归方程为Y=-0.2341X+0.1193(R2=0.9878),中值(IC50)为36 ng/mL,最低检测限(LOD)为10 ng/mL,标准曲线的线性范围为10~1000 ng/mL。批内变异系数为3.18%~7.64%,批间变异系数为9.69%~11.94%,鸡组织中的ENR的回收率为76.5%~89.42%。本试验建立的ELISA方法能够满足恩诺沙星兽药残留检测要求。     

检测莱克多巴胺胶体金免疫层析试验的建立

采用混合酸酐法制备莱克多巴胺-OVA偶联抗原,胶体金标记莱克多巴胺单克隆抗体,建立了检测莱克多巴胺的胶体金免疫层析试验。该试验具有较好的敏感性和特异性,最低可检测10ng/mL的莱克多巴胺,而与克伦特罗和沙丁醇胺无交叉反应。胶体金免疫层析试验对尿液和饲料样品中莱克多巴胺的最低检测量分别为10ng/mL和0.01mg/kg。     

氧氟沙星免疫亲和色谱柱的研制

本试验将氧氟沙星与载体蛋白偶联成人工抗原,用合成的免疫原免疫家兔,制备出高效价抗OFL血清。经纯化后研制出针对OFL特异性吸附的免疫亲和色谱柱,并对色谱柱进行了评价,偶联率为93%,动态柱容量为2204ng/mL,分别添加5mL200ng/mL、300ng/mL和400ng/mL氧氟沙星标准工作液,5mL甲醇洗脱,高效毛细管电泳检测,连续测定6次,测得其回收率为94%、92.67%、95.5%,变异系数为5.32%、3.17%、3.84%。     

盐酸四环素人工抗原的合成及鉴定

本试验旨在合成盐酸四环素人工抗原,为其单克隆抗体的制备奠定试验基础。将盐酸四环素(TCH)发生霍夫曼降解和重氮化反应生成重氮盐,再与蛋白质载体(BSA,OVA)偶联生成免疫原和包被原,对偶联产物采用三氯化铁及紫外扫描法鉴定偶联成功,且免疫原和包被原的摩尔结合比分别约为3.4∶1和4.2∶1。用免疫原免疫BALB/c小鼠,用间接ELISA检测抗体效价,采用竞争ELISA法测IC50,获得了效价为1∶51200I、C50为16.91 ng/mL的多克隆抗体,最终证明人工抗原制备成功。     

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.     

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

Tropical Animal Health and Production -     

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.     

Chemotaxis of macrophage in inflammation

Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.     

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