磺胺二甲嘧啶药物残留ELISA检测试剂盒的研制及初步应用

本试验旨在采用重氮化法合成的免疫抗原通过免疫BALB/c小鼠进行融合,获得高特异、高灵敏度的单克隆抗体。在建立磺胺二甲嘧啶单克隆抗体(SM2 mAb)杂交瘤细胞株和阻断ELISA的基础上,初步研制出一种一步法检测磺胺二甲嘧啶(SM2)的ELISA快速检测试剂盒(SM2-Kit)。结果表明:SM2-Kit检测范围为0.5～40.5μg/L,检测时间为30 min,IC50为1.4μg/L,最低检测限达0.1μg/L。经大量现场试验,猪肉组织最低检测限为1μg/kg,猪饲料最低检测限为1μg/kg,猪尿最低检测限为1.8μg/L,牛奶最低检测限为1.5μg/L,测试的回收率平均在70%～110%。     

金黄色葡萄球菌肠毒素ELISA检测方法的建立及应用

采用金黄色葡萄球菌肠毒素A(SEA)和金黄色葡萄球菌肠毒素B(SEB)免疫Balb/c小鼠制备相应的单克隆抗体(m Ab),并以此为基础建立SEA和SEB的ELISA检测方法,用于牛乳中金黄色葡萄球菌肠毒素的检测。SEA双抗体夹心法ELISA的曲线范围是1~16μg/L,相关系数R2=0.9996,检测牛乳的检测限是0.431μg/L,加标4μg/L和10μg/L,准确度分别为89.18%和97.62%。SEB双抗体夹心法ELISA的曲线范围是0.5~8μg/L,相关系数R2=0.9998,检测牛乳的检测限是0.335μg/L,加标4μg/L和10μg/L,准确度分别为107.83%和89.88%。     

应用胶体金免疫层析法测定牛奶中的磺胺类药物残留

应用胶体金免疫层析法对牛奶中的磺胺类药物残留进行检测,研究该方法的灵敏度、假阳性率、假阴性率及特异性。结果表明,用胶体金免疫层析法测定牛奶中的磺胺类药物,检测限分别为磺胺嘧啶60μg/L、磺胺二甲基嘧啶20μg/L、磺胺喹噁啉80μg/L、磺胺氯哒嗪30μg/L、磺胺间二甲氧嘧啶50μg/L、磺胺间甲氧嘧啶50μg/L、磺胺甲噁唑80μg/L、磺胺苯酰50μg/L、磺胺对甲氧嘧啶30μg/L、磺胺异噁唑10μg/L、磺胺甲氧哒嗪70μg/L、磺胺多辛70μg/L,假阳性率为2%,假阴性率为0;方法的特异性较好,对其他抗生素无交叉反应;检测实际样本的结果与液相色谱-质谱/质谱法基本一致。可见,该方法简便、快速、准确、稳定,适用于牛奶中磺胺类药物残留的现场快速检测。     

藏猪和大约克夏猪血清中脂代谢相关细胞因子的发育性变化研究

采用酶联免疫吸附方法(ELISA)检测了2、4、6月龄藏猪和大约克夏猪血清中甘油三酯、瘦素和脂联素含量。结果表明,2、4、6月龄藏猪和大约克夏猪血清中甘油三酯含量分别为26.17μmol/L和24.25μmol/L、29.36μmol/L和37.88μmol/L、28.39μmol/L和37.88μmol/L;瘦素含量分别为2 403.82 ng/L和2 080.21 ng/L、2 513.31 ng/L和2 060.91 ng/L、2 564.75 ng/L和2 068.05 ng/L,脂联素含量分别为78.28μg/L和104.94μg/L、94.84μg/L和129.13μg/L、95.23μg/L和103.01μg/L。试验探索了藏猪和大约克夏猪脂肪代谢相关细胞因子的发育性变化规律和差异,为深入研究猪脂肪沉积机理提供了基础数据。     

超高效液相色谱-紫外检测法测定肾复康合剂中落新妇苷和芦丁的含量

建立了超高效液相色谱(UPLC)测定肾复康合剂中主成分落新妇苷和芦丁的含量。采用反相高效液相色谱法对落新妇苷和芦丁进行色谱分离和快速定量测定。以ACQUITY UPLCTM C18色谱柱(2.1 mm×100 mm,1.7μm)为分离柱,柱温35℃;以乙腈-0.1%甲酸水溶液进行梯度洗脱;流速0.35 m L/min;进样量5μL;检测波长为204 nm。通过光谱图、保留时间和峰面积参数对落新妇苷和芦丁进行定性定量检测。落新妇苷在2～75μg/m L的范围内线性关系良好(R~20.998);方法检出限为1μg/m L,方法定量限为2μg/m L;芦丁在4～150μg/m L的范围内线性良好(R~20.996);方法检出限为2μg/m L,方法定量限为4μg/m L,完全满足检测需求。该方法色谱分离较好,分析速度较快,前处理简单,适用于肾复康合剂中落新妇苷和芦丁的定性定量检测。     

胶体金免疫层析法测定牛奶中β-内酰胺类抗生素和三聚氰胺残留

应用胶体金免疫层析法对牛奶中的β-内酰胺类抗生素和三聚氰胺残留进行检测,考察该法的灵敏度、假阳性率、假阴性率、特异性及准确性。结果表明：用胶体金免疫层析法测定牛奶中的β-内酰胺类抗生素和三聚氰胺,检测限分别为青霉素G 2μg/L、氨苄青霉素3μg/L、阿莫西林4μg/L、苯唑青霉素6μg/L、邻氯青霉素6μg/L、双氯青霉素6μg/L、萘夫西林20μg/L、头孢喹肟20μg/L、头孢哌酮40μg/L、头孢曲松50μg/L、头孢噻呋90μg/L、头孢洛宁10μg/L、三聚氰胺50μg/L,假阳性率不大于5%,假阴性率为0;方法特异性较好,与牛奶中常见的其他抗生素无交叉反应;结果准确可靠,对实际样本的检测结果与液相色谱-质谱/质谱法基本一致。该方法简便、快速、准确、稳定,可作为牛奶中β-内酰胺类抗生素和三聚氰胺残留现场快速检测的一种有效手段。     

猪瘟RT-PCR ELISA诊断方法的建立

将RT—PCR方法和高灵敏度的地高辛检测系统相结合，先建立猪瘟病毒（classicalswinefevervirus，CSFV）的RT—PCR方法，用地高辛标记RT—PCR产物；再建立CSFV的PCR—ELISA方法，用生物素标记的探针在链亲和素包被的微量板孔中杂交捕获地高辛标记的PCR产物，最后进行免疫显色得出结果。试验主要对RT—PCRELISA的各种反应条件进行了优化，确定了1mg／L的链亲和素、50μg／L生物素标记的探针、1：3000抗地高辛的过氧化物酶、37C杂交2h等为最适反应条件。该方法的敏感性比常规琼脂糖凝胶电泳检测高100倍以上，克服了组织样品中CSFV含量少而难以检测的困难，为猪瘟的早期诊断和分子流行病学调查提供了一条新途径。     

鸡肉组织中环丙沙星残留的ELISA与HPLC检测方法比较

利用单克隆抗体间接竞争ELISA方法测定了鸡肉中环丙沙星的残留,同时利用HPLC方法进行了比较分析。间接竞争ELISA法的线性范围为6.25~400μg/L,最低检测限为4.10μg/L。HPLC法的线性范围为0.06~500μg/L,最低检测限为0.06μg/L。在标准品添加量为1.5625×10-4~1.25×10-3g/kg时,ELISA方法的平均回收率为73.81%,批内变异系数为8.75%,HPLC方法平均回收率为80.41%,批内变异系数为1.27%。结果显示,ELISA方法与HPLC方法具有很好的相关性(r2=0.9925),该ELISA方法可用于鸡肉样品中环丙沙星的检测。     

水产品中甲砜霉素、氟苯尼考和氟苯尼考胺酶联免疫多残留测定

将氟苯尼考胺与载体蛋白相连作为抗原免疫动物,获得抗甲砜霉素等药物的抗体,建立了水产品中甲砜霉素、氟苯尼考和氟苯尼考胺残留的ELISA检测方法。结果显示,人工抗原中氟苯尼考胺与蛋白质分子的结合比约为12∶1,血清效价达到1∶2000倍以上,50%抑制浓度(IC50)为3μg/L左右,3种酰胺醇类药物交叉反应率在30%～156%之间,鱼和虾肌肉组织中的检测限分别为6.3μg/kg和6.1μg/kg,在鱼和虾肌肉组织中三种药物的回收率在40%～120%之间,检测范围为0.2～125μg/L。该方法可同时测定甲砜霉素、氟苯尼考及其标示残留物氟苯尼考胺等3种化合物残留量。方法灵敏度、精密度和准确度均能满足兽药残留筛选检测要求。     

液相色谱-串联质谱法测定猪血浆和尿液中8种同化激素的残留

为建立猪血浆和尿液中8种同化激素的液相色谱-串联质谱(LC-MS/MS)检测方法,样品酶解后,用乙酸乙酯超声提取,经C18固相萃取小柱净化,进行LC-MS/MS检测。结果表明,采用基质添加标准曲线消除基质干扰,8种同化激素在1.5μg/L~100μg/L内,相关系数均大于0.99,线性关系良好。除炔诺酮定量限为1.5μg/L,其他7种药物定量限均为1μg/L。在2、10、50μg/L添加水平下,药物的回收率为71.5%~92.3%,日内相对标准偏差(RSD)为2.2%~14.6%,日间RSD为3.2%~12.7%。本方法灵敏度高,适用于同化激素类药物残留的检测分析。     

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