国内外克伦特罗ELISA检测试剂盒评价

根据B/B0-50%抑制浓度、检测范围、标准溶液浓度梯度、板内变异、板间变异、样品添加检验、实际样品检验等方面的比较结果对两种克伦特罗ELISA检测试剂盒(A: 中国兽医药品监察所研制, B: 德国 r-Biopharm公司研制)进行评价。结果表明,试剂盒A的50%抑制浓度低于1.0 ng/mL; 检测范围在0.10~3.0 ng/mL之间;标准溶液浓度梯度中包括1.0 ng/mL这一限定值;板内变异系数小于13.7%,板间变异系数小于8.8%;样品回收率在70%~110%之间;实际样品检验和试剂盒B检样的阳性符合率为95.5%。试验证明,试剂盒A与试剂盒B的水平相当。     

食品中呋喃妥因代谢物酶联免疫检测试剂盒的研制

目的：开发研制快速检测呋喃妥因代谢物的酶联免疫检测试剂盒。方法：依据直接竞争ELISA原理,采用棋盘包被法确定最佳抗体包被浓度和酶标抗原工作浓度、包被条件、反应时间、底物显色时间等,并对试剂盒的各项技术指标进行确认。结果：成功的组装了呋喃妥因的酶联免疫检测试剂盒,并建立了肌肉、肝脏、水产、蜂蜜等的前处理方法,检测限均远低于1μg／kg。该试剂盒线性检测范围为0～4．05ng／mL,IC。浮动范围0．30～0．60ng／mL,样品的板内、批内、批间的变异系数均小于15％,平均回收率在65％～90％之间,与其同类药物的交叉反应率均小于O-2％。结论：本研究研制的试刺盒重复性、再现性、特异性、稳定性各项指标均符合技术要求,可用于动物源性食品中呋喃妥因代谢物残留的检测。     

不同细胞因子对水牛原始生殖细胞传代培养的影响

为探讨不同细胞因子对水牛原始生殖细胞（PGCs）传代培养的影响，将PGCs分别采用A、B、C、D、E、F和G共7种培养基进行培养，即A组：基础液＋10ng／mL白血病抑制因子（LIF）＋10ng／mL碱性成纤维细胞生长因子（bFGF）；B组：基础液＋20ng／mL LIF＋20ng／mL bFGF；C组：基础液＋20ng／mL LIF＋10ng／mL bFGF；D组：基础液＋20ng／mL LIF；E组：基础液＋20ng／mL LIF＋20ng／mL bFGF＋20ng／mL干细胞因子（SCF）；F组：基础液＋20ng／mL LIF＋40ng／mL bFGF＋40ng／mL SCF；G组（对照组）：基础液。将机械法分离的PGCs小集落接种到水牛胎儿成纤维细胞（BEF）饲养层上进行传代培养。结果，原代时，A、B、C、D、E和F组的克隆数目都显著高于对照组（P％0．05），其中E和F组的克隆数目显著高于A组（P〈0．05），而与B、C、D组差异均不显著（P〉0．05）；1～8代时，B、C、D、E、F组的克隆数目显著高于A组（P〈0．05）；对照组传代数仅为2代，A组为5代，而B、C、D、E和F组均为8代以上。结果表明，在传代过程中，LIF起主要作用，20ng／mL的LIF浓度可以满足水牛PGCs传代培养的需要。     

酶联免疫吸附法检测鸡肝肾中氯霉素残留的分析

试验用六种浓度的氯霉素标准品(0.025ng／mL,0.05ng／mL,0.1ng／mL,0.2ng／mL,0.5ng／mL,2ng/mL)做工作标准曲线,设计鸡肝脏、肾脏两个待测样品,同时分别加六种标准品于肝脏和肾脏中测定样品中氯霉素的回收率。试验结果表明:ELESA方法测定鸡组织中氯霉素的检出限为0.02ng／mL,样品中不同浓度的氯霉素标准品回收率均达84.8％以上。说明该方法灵敏、准确。     

氯霉素竞争ELISA检测方法的研究

用抗氯霉素的MAb 2G2建立了检测氯霉素的竞争ELISA,对主要影响因素进行了研究,其回归方程为y=0.3522x+0.5939,相关系数为RZ=0.9906,检测线性范围为0.098 ng/mL～25 ng/mL,半数抑制浓度(IC50)为1.848 ng/mL.检测限为0.135 ng/mL.与氯霉素琥珀酸钠交叉反应率为143%,与其它结构类似物和常见抗菌素的交叉反应率均小于0.01%.批内和批间变异系数分别为4.98%和9.42%,牛奶样的平均添加回收率为101.31%.所建立的检测氯霉素竞争ELISA法,符合检测氯霉素残留的要求,为氯霉素残留快速检测试剂盒的研制奠定了基础.     

3种ELISA试剂盒检测盐酸克伦特罗效果评价

用3种盐酸克伦特罗ELISA检测试剂盒对10份未知猪尿液样品及5份标准浓度猪尿液样品进行检测,以比较试剂盒的检测效果。结果表明,试剂盒A在盐酸克伦特罗浓度为0ng／mL-10ng／mL的范围内其检测结果较准确,当浓度大于10ng／mL时其检测结果偏小;试剂盒B对盐酸克伦特罗的检测结果较标准样品浓度有时偏高,有时偏低,结果不够准确;试剂盒C的检测结果与标准样品的实际浓度相近,结果较准确。稳定性方面,试剂盒B的稳定性差,而试剂盒A及试剂盒C的稳定性较好。总的来说,试剂盒C在检测结果的准确性和稳定性上均较好,是3种试剂盒中效果最为理想的盐酸克伦特罗检测试剂盒。     

食品中呋哺妥因代谢物酶联免疫检测试剂盒的研制

目的:开发研制快速检测呋喃妥因代谢物的酶联免疫检测试剂盒.方法:依据直接竞争ELISA原理,采用棋盘包被法确定最佳抗体包被浓度和酶标抗原工作浓度、包被条件、反应时间、底物显色时间等,并对试剂盒的各项技术指标进行确认.结果:成功的组装了呋喃妥因的酶联免疫检测试剂盒,并建立了肌肉、肝脏、水产、蜂蜜等的前处理方法,检测限均远低于1μg／kg.该试剂盒线性检测范围为0～4.05ng／mL,IC50浮动范围0.30～0.60ng/mL,样品的板内、批内、批间的变异系数均小于15％,平均回收率在65％～90％之间,与其同类药物的交叉反应率均小于0.2％.结论:本研究研制的试剂盒重复性、再现性、特异性、稳定性各项指标均符合技术要求,可用于动物源性食品中呋喃妥因代谢物残留的检测.     

高灵敏度酶联免疫法快速检测动物源性产品中氯霉素残留的研究

本试验旨在应用酶联免疫吸附法(ELISA)检测动物组织中氯霉素的残留。根据试剂盒操作说明对样本进行前处理,样品中的氯霉素与氯霉素酶结合物竞争结合酶标板微孔中固相化的氯霉素特异性抗体,根据酶催化显色剂显色的深浅来判断样品中氯霉素含量。试验结果显示,该方法对样品的检测限在0.1 μg/kg以下;以20~300 ng/kg浓度的氯霉素添加到动物源性产品中,其回收率范围74.4%~105.4%;变异系数在15%以下。结果表明建立的ELISA试剂盒能满足检测动物源性产品中氯霉素残留的需要。     

动物组织中磺胺二甲嘧啶残留检测ELISA试剂盒的研制

在建立竞争ELISA方法的基础上，首次研制出检测磺胺二甲嘧啶的单克隆抗体快速检测试剂盒，并对其检测限、精密度、检测范围以及鸡肌肉组织中的添加回收实验做了详细研究。本试剂盒的检测限为1．0ng／m1，检测范围为1．0-81．0ng／m1，批内变异系数＜8．9％，批间变异系数＜9．5％，在10、60和200ng／m1水平鸡肌肉组织中添加，回收率为64．5％-85．5％，变异系数为6．0％-18．6％。与同类相关德国产试剂盒相比较，阳性符合率为100％。     

猪肝和猪尿中沙丁胺醇和克伦特罗残留的酶联免疫吸附检测法研究

采用混合酸酐法将沙丁胺醇与牛血清白蛋白偶联，并免疫家兔制备抗沙丁胺醇抗血清。以间接ELISA法测定血清效价，测得抗血清最佳工作浓度为1：6400，该抗沙丁胺醇抗血清对克伦特罗有110％的交叉反应性。建立了能够同时检测SAL和CL的间接竞争ELISA方法，该方法对沙丁胺醇的检测范围为0．48ng／mL～8．0μg／mL，对克伦特罗的检测范围为0．43ng／mL～7．3μg／mL，对沙丁胺醇的检测灵敏度为o．48ng／mL，对克伦特罗的检测灵敏度为0．43ng／mL。在猪肝和猪尿中添加1～50ng／g(ng／mL)的沙丁胺醇，添加回收率为72．2％～84．8％，变异系数为4．2％～28．3％，在猪肝脏和猪尿中添加1～50ng／g(ng／mL)的克伦特罗，添加回收率为84．3％～103．4％，变异系数为O．3％～35．5％。     

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 -