酶联免疫法测定生猪肉中呋喃妥因代谢物的残留量

用竞争酶联免疫(ELISA)法测定生猪肉中呋喃妥因代谢物(AHD:1-氨基-2-内酰脲)残留量,本文概述了酶联免疫法检测的基本原理、步骤,并在我所长期进行酶联免疫法检测的基础上,提出了几点关键性的注意事项,本法操作简单快捷、灵敏准确、方便实用,可作为生猪肉中呋喃妥因代谢物残留量检测的快速筛选方法。     

呋喃妥因残留代谢物人工抗原的合成与鉴定

利用对醛基苯甲酸对呋喃妥因代谢物1-氨基乙内酰脲(1-Aminohydantoin hydrochloride,AHD)进行衍生化,衍生物1-氨基乙内酰脲-4-羧苯基肟(CPAHD)通过混合酸酐法与牛血清蛋白(bovine serum albumin,BSA)偶联,用紫外扫描(UV)和变性凝胶电泳(SDS-PAGE)对偶联物进行验证。将偶联成功的人工全抗原(CPAHD-BSA)免疫BALB/c小鼠,通过间接酶联免疫吸附法(ELISA)测定小鼠血清抗体效价为1:32 000。用间接竞争ELISA鉴定抗体特性,结果显示:抗体对AHD与对硝基苯甲醛的衍生物(NPAHD)的灵敏度高,IC50为30.63μg/L,特异性好,与CPAHD有部分交叉反应外,与其他3类硝基呋喃类药物及代谢产物无交叉反应(交叉反应率<0.01%)。结果表明,用CPAHD-BSA作免疫原免疫小鼠可诱导产生针对AHD衍生物(NPAHD)的特异性抗体,为进一步制备AHD单克隆抗体和研制快速筛选检测试剂盒奠定了基础。     

达氟沙星间接竞争ELISA检测方法的建立

将达氟沙星（danofloxacin, DFLX）与牛血清白蛋白(BSA)、卵清白蛋白(OVA)偶联分别作为免疫原与包被原, 达氟沙星为竞争的半抗原，建立间接竞争ELISA检测方法。试验结果表明,理想的包被抗原浓度为1.25 μg/L, 多抗(DFLX-PcAb)工作浓度为1∶10000,酶标二抗的工作浓度为1∶4000,最适检测范围为0.1～10 ng/L,最低检测限为0.2 ng/L, 批内和批间变异系数分别为3.81%和6.25%。得到回归方程y=0.7975-0.125x（R2=0.989）和标准曲线，从而建立了DFLX的快速检测残留的间接竞争酶联免疫吸附试验（ci-ELISA）。     

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.     

呋喃妥因代谢物AHD单抗的制备及鉴定

将呋喃妥因代谢物1-氨基-乙内酰胺脲(AHD)的衍生物1-氨基乙内酰脲-4-羧苯基肟(CPAHD)分别与牛血清蛋白(BSA)和Jeffamine修饰的卵清蛋白(OVA)偶联,经紫外光谱扫描鉴定,成功合成了免疫抗原CPAHD-BSA和包被抗原CPAHD-Jeffamine-OVA。应用杂交瘤技术将免疫鼠脾细胞与骨髓瘤细胞SP2/0融合,获得了稳定分泌抗4-NPAHD单克隆抗体的杂交瘤细胞株,命名为B10E7。使用本细胞株制备的McAb对4-NPAHD的半数抑制质量浓度(IC50)为3.65 ng/mL,与同类抗生素及其代谢物未发现交叉反应,显示高度的灵敏性和特异性。本抗体的研制为建立间接竞争酶联免疫方法奠定了基础。     

牛奶及奶粉中三聚氰胺残留酶联免疫检测方法的研究

通过4,6-二氨基-2-氯-1,3,5-三嗪与对氨基苯丁酸反应获得三聚氰胺半抗原,再以活性酯法与载体蛋白偶联制备三聚氰胺免疫原或包被原。免疫BALB/c小鼠,利用杂交瘤技术制备出针对三聚氰胺的特异性单克隆抗体。采用间接竞争酶联免疫吸附法(ciELISA)建立检测三聚氰胺的标准曲线,线性范围是17.4～345.5ng/mL,50%抑制浓度(IC50)61.3ng/mL。牛奶和奶粉加标回收率在68.1%～91.0%,变异系数在2.4%～14.5%。结果表明,该方法可以满足牛奶和奶粉中三聚氰胺残留分析要求。     

呋喃唑酮代谢物人工抗原的合成及抗体的制备

为改进和完善免疫检测呋喃唑酮代谢物方法,制备了抗呋喃唑酮代谢物(AOZ)特异性抗体.采用对醛基苯甲酸对AOZ进行衍生化得到CPAOZ,还原CPAOZ结构中的C=N双键得到半抗原,半抗原用N-羟基琥珀酰亚胺活化酯法与BSA偶联制备免疫原,免疫新西兰大白兔制得特异性抗体,采用间接(竞争)ELISA法评价抗血清效价及特异性.结果显示,试验获得了较高效价(1∶1280000)的抗AOZ血清,AOZ半抑制浓度为5.9 ng/mL;抗血清与结构类似物呋喃它酮代谢物的交叉反应率仅为0.76％,与呋喃妥因代谢物和呋喃西林代谢物无交叉反应;利用该抗体建立的间接竞争ELISA检测法,AOZ在1～27 ng/mL与抑制率呈线性关系.结果表明,该特抗体虽然灵敏度较低,却对AOZ而非AOZ衍生物有特异性,可为畜产品中AOZ残留检测提供新的思路和方法.     

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。     

猪表皮生长因子间接竞争ELISA检测方法的建立

为建立酶联免疫吸附试验(enzyme-linked immunosorbent assay,ELISA)检测猪血清或尿液中猪表皮生长因子(porcinee pidermal growth factor,pEGF)的含量,以pEGF为包被原,人表皮生长因子(hu-mane pidermal growth factor,hEGF)为竞争抗原,两者与一定量的抗pEGF多抗反应。结果表明,理想的包被抗原浓度为0.625μg/mL,抗pEGF工作浓度为1∶64000,酶标二抗工作浓度为1∶20000,可检测的最适范围为0.4ng/mL~32ng/mL,最低检测限为1ng/mL,批内和批间变异系数分别为3.50%和5.22%。得到回归方程y=-34.53x 76.06(R2=0.993)和标准曲线,从而建立了快速定量测定pEGF含量的酶联免疫吸附试验方法。     

液相色谱-串联质谱法检测鸡肌肉组织中硝基呋喃类代谢物的研究

建立了一种专属、灵敏的液相色谱-串联质谱法,同时检测鸡肌肉组织中硝基呋喃类代谢物：呋喃唑酮代谢物AOZ、呋喃它酮代谢物AMOZ,呋喃妥因代谢物AHD和呋喃西林代谢物SEM.鸡肌肉组织中硝基呋喃类代谢物经衍生化、提取后,采用电喷雾离子源,正离子检测方式进行分析.在0.5～20 ng/mL浓度范围内,4种硝基呋喃类代谢物均呈线性,相关系数r＞0.99.在0.5、1和2 μg/kg 3种添加浓度,AOZ、AMOZ、AHD和SEM相应的平均回收率在80%～120%,RSD＜16%.4种硝基呋喃类代谢物的检测限均可达到0.25 μg/kg.该方法专属性强、灵敏度高,适用于鸡肌肉组织中硝基呋喃类代谢物的检测.     

白术、微米白术和白术多糖对断奶仔猪生长性能和肠道形态及微生态区系的影响

试验选用96头平均体重14.82 kg左右的杜×长×大断奶仔猪,随机分成4组,每组3栏,每栏8头(公母各半)。对照组饲喂基础日粮,试验1、2、3组分别添加1%80目白术、0.2%白术多糖和1%微米白术。试验期30 d。结果表明:在生长性能方面,与对照组相比,1%微米白术添加组可显著提高日增重(P0.05)、降低饲料增重比和腹泻率,而且效果优于1%80目白术组和0.2%白术多糖组,在肠道形态和肠道微生态区系方面,与对照组相比,日粮添加1%80目白术、0.2%白术多糖、1%微米白术均可不同程度的提高十二指肠和空肠的绒毛高度,加深十二指肠和空肠的隐窝深度,并且增加肠道微生态区系的多样性,其中以1%微米白术添加组的效果最佳。     

Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia

Sissay, M.M., Uggla, A. and Waller, P.J., XXXX. Prevalence and seasonal incidence of nematode parasites and fluke infections of sheep and goats in eastern Ethiopia. Tropical Animal Health and Production, XXXX. A 2-year abattoir survey was carried out to determine the prevalence, abundance and seasonal incidence of gastro-intestinal (GI) nematodes and trematodes (flukes) of sheep and goats in the semi-arid zone of eastern Ethiopia. During May 2003 to April 2005, viscera including liver, lungs and GI tracts were collected from 655 sheep and 632 goats slaughtered at 4 abattoirs located in the towns of Haramaya, Harar, Dire Dawa and Jijiga in eastern Ethiopia. All animals were raised in the farming areas located within the community boundaries for each town. Collected materials were transported within 24 h to the parasitology laboratory of Haramaya University for immediate processing. Thirteen species belonging to 9 genera of GI nematodes (Haemonchus contortus, Trichostrongylus axei, T. colubriformis, T. vitrinus, Nematodirus filicollis, N. spathiger, Oesophagostomum columbianum, O. venulosum, Strongyloides papillosus, Bunostomum trigonocephalum, Trichuris ovis, Cooperia curticei and Chabertia ovina), and 4 species belonging to 3 genera of trematodes (Fasciola hepatica, F. gigantica, Paramphistomum {Calicohoron} microbothrium and Dicrocoelium dendriticum) were recorded in both sheep and goats. All animals in this investigation were infected with multiple species to varying degrees. The mean burdens of adult nematodes were generally moderate in both sheep and goats and showed patterns of seasonal abundance that corresponded with the bi-modal annual rainfall pattern, with highest burdens around the middle of the rainy season. In both sheep and goats there were significant differences in the mean worm burdens and abundance of the different nematode species between the four geographic locations, with worm burdens in the Haramaya and Harar areas greater than those observed in the Dire Dawa and Jijiga locations. Similar seasonal variations were also observed in the prevalence of flukes. But there were no significant differences in the prevalence of each fluke species between the four locations. Overall, the results showed that Haemonchus, Trichostrongylus, Nematodirus, Oesophagostomum, Fasciola and Paramphistomum species were the most abundant helminth parasites of sheep and goats in eastern Ethiopia.     

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.     

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

Tropical Animal Health and Production -     

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.     

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.     

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.     

Y‐chromosomal variation of local goat breeds of Turkey close to the domestication centre

Genetic variations in chromosome Y are enabling researchers to identify paternal lineages, which are informative for introgressions and migrations. In this study, the male‐specific region markers, sex‐determining region‐Y (SRY), amelogenin (AMELY) and zinc finger (ZFY) were analysed in seven Turkish native goat breeds, Angora, Kilis, Hair, Honaml?, Norduz, Gürcü and Abaza. A SNP in the ZFY gene defined a new haplotype Y2C. All domestic haplogroups originate from Capra aegagrus, while the finding of Y1A, Y1B, Y2A and Y2C in 32, 4, 126 and 2 Turkish domestic goats, respectively, appears to indicate a predomestic origin of the major haplotypes. The occurrence of four haplotypes in the Hair goat and, in contrast, a frequency of 96% of Y1A in the Kilis breed illustrate that Y‐chromosomal variants have a more breed‐dependent distribution than mitochondrial or autosomal DNA. This probably reflects male founder effects, but a role in adaptation cannot be excluded.     

Changes in proportion of canine urinary calculi composed of calcium oxalate or struvite in specimens analyzed from 1981 through 2001

The objective of this report was to characterize 20-year changes in proportion of calcium oxalate (CaOx) calculi and struvite calculi in dogs, and associations with breed, age, and sex. In this retrospective study, results of analysis of urinary calculi from dogs were reviewed for specimens received between July 1, 1981, and December 31, 2001. Breed, sex, age, year of submission of the specimen, and mineral type(s) were analyzed statistically. CaOx or Struvite or both were contained in 18,966 of 20,884 (91%) specimens. For both sexes, a 20-year statistically significant increase was observed in the proportion of calculus specimens that contained CaOx. The increase in this proportion was greater in females (1% to 31%) than in males (18% to 82%). From 1998 to 2001, when proportions may have plateaued, the odds of specimens containing CaOx were markedly higher in 18 breeds, markedly lower in 5 breeds, and not significantly different in 13 breeds compared with crossbreds. For both sexes, a 20-year statistically significant decrease was observed in the proportion of calculus specimens that contained struvite. This decrease in proportion was greater for males (79-16%) than for females (97-68%). From 1998 to 2001, when proportions plateaued, the odds of calculi containing struvite were markedly lower in 20 breeds, markedly higher in 1 breed, and not significantly different in 15 breeds when compared with crossbreds. Breed, age, and sex were associated statistically with CaOx or struvite urolithiasis. In conclusion, there appears to have been a long-term increase in the proportion of specimens of canine urinary calculi that contain CaOx as well as a long-term decrease in the proportion of specimens of calculi that contain struvite for both male and female dogs. The rate of change appeared to begin leveling off in the period 1998 to 2001. The recent proportion of dogs with either CaOx- or struvite-associated urolithiasis may depend on breed, age, and sex, and on interactions among these 3 factors.     

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.