高效液相色谱法测定猪肉组织中莱克多巴胺的残留

用乙酸乙酯-正丁醇混合液为提取剂提取猪肉组织中的莱克多巴胺,经固相萃取柱净化,浓缩后用2%乙酸溶液定容,用高效液相色谱-荧光检测法分离测定;色谱柱为C18柱,长250mm,内径4.6mm,粒度5μm;流动相为戊烷磺酸钠溶液:乙腈(78:22,V/V);激发波长为226nm,发射波长为306nm;流速1mL/min;进样量50μl;猪肉组织中莱克多巴胺的检测限为5μg/kg;莱克多巴胺的测定在2.5～25ng/mL范围内具有良好的线性关系,平均回收率在85.0%以上,RSD小于2.5%;方法简单,灵敏度高,可用于猪肉组织中莱克多巴胺残留的测定。     

猪饲料中莱克多巴胺的GC/MS快速测定

本实验对猪饲料中莱克多巴胺的气相色谱-质谱快速检测方法进行了研究.采用酸性甲醇-水提取饲料中的莱克多巴胺,经乙酸乙酯萃取和酸性氧化铝固相萃取柱净化,衍生化后用气相色谱-质谱法检测和确证.结果表明,方法平均回收率为70.8%～83.8%,日间变异系数为4.5%～11.1%(n=3),配合饲料检测限和定量限分别为0.5μg/g和1.0 μg/g,预混合饲料检测限和定量限分别为0.3 μg/g和0.7 μg/g.该方法适合饲料中莱克多巴胺的确证和定量分析.     

猪肉及组织中β-受体激动剂UPLC-MS/M检测方法研究

超高效液相色谱串联质谱法(UPLC-MS/MS)检测猪肉中克伦特罗、莱克多巴胺、沙丁胺醇3种β-受体激动剂残留方法.选用盐酸葡萄糖醛苷酶/芳基硫酸酯酶水解,混合型阳离子交换固相萃取净化,以0.1%甲酸水溶液-0.1%甲酸乙腈溶液-甲醇为流动相,超高效液相色谱串联质谱法检测,在1.0、5.0、10μg/kg浓度添加水平,空白肌肉组织中3种药物添加平均回收率范围84~95%,标准偏差3.6~8.1%.该方法检测限为0.1μg/kg,定量限为0.3μg/kg,具有准确敏感特性.     

液相色谱/串联质谱法检测猪肉中三种化学物质的残留试验

本试验建立了高效液相色谱-串联质谱（HPLC-MS/MS）检测猪肉中克伦特罗、沙丁胺醇、莱克多巴胺残留的方法。样品中的药物残留采用0.2mol/L pH5.2的乙酸铵缓冲液提取,加入β-葡萄糖醛酸酶/芳基硫酸酯酶进行酶解,提取液经混合型阳离子交换柱进行净化,液相色谱-串联质谱测定,内标法定量。克伦特罗0.05μg/kg;莱可多巴胺、沙丁胺醇0.2μg/kg。回收率均大于88%。     

动物组织中莱克多巴胺残留的不确定度评定

为保证实验室测试结果的准确性和可靠性,依照国家计量技术规范JJF1059—199《测量不确定度评定与表示》,对气相色谱-质谱法测定动物组织中莱克多巴胺残留量进行了不确定度的评定。分析和量化了影响测定结果的各不确定度分量,得出了被测量的合成标准不确定度和扩展不确定度。当动物组织中莱克多巴胺残留量为17．72μg／kg时,其合成标准不确定度为0．47μg／kg,扩展不确定度为0．94μg／kg（k=2）。     

气相色谱－质谱法测定猪尿中莱克多巴胺

建立了猪尿中莱克多巴胺的气相色谱-质谱（GC-MS）检测方法。样品经β-盐酸葡萄糖醛苷酶/芳基硫酸酯酶水解,乙酸乙酯提取、盐酸溶液萃取,SCX固相萃取柱净化,N,O-双三甲基硅基-三氟乙酰胺（BSTFA）衍生化后进行气相色谱-质谱测定。结果表明,方法检出限为0.3μg/L,定量限为0.5μg/L,线性范围为10-500μg/L。在2、4、8μg/L三个添加浓度水平上,莱克多巴胺的平均回收率为85%-115%,批内、批间相对标准偏差均小于10%。     

饲料中莱克多巴胺的HPLC法测定

用碱性甲醇提取试样中的莱克多巴胺,经SLA固相萃取柱净化,浓缩后用2%乙酸溶液定容,过膜后用高效液相色谱-荧光检测法分离测定;色谱柱类型Waters Svmmetry C18柱,250mm×4.6mm(i.d.),粒径5μm;流动相为戊烷磺酸钠溶液:乙腈(体积比80:20);激发波长为226nm,发射波长为306nm;流速1ml/min;进样量50μl;饲料中莱克多巴胺的检测限为0.5mg/kg;莱克多巴胺的测定在0.02-0.50μg/ml范围内具有良好的线性关系,平均回收率在85.1%以上,RSD小于7.5%;方法简单,灵敏度高,可用于饲料中莱克多巴胺的含量测定。     

液相色谱-串联质谱法测定猪肉中3种β-受体激动剂类药物残留

试验建立了液相色谱-串联质谱(LC-MS/MS)检测猪肉中的克仑特罗、沙丁胺醇、莱克多巴胺残留的方法,并对方法进行了优化。样品经0.2 mol/L的乙酸铵缓冲液提取,加入β-葡萄糖醛苷酶进行酶解,提取液经PCX柱进行净化,液相色谱-串联质谱进行测定,内标法定量。结果显示,猪肉中3种β-受体激动剂残留浓度在0.2~10 μg/kg范围线性关系良好,线性相关系数分别为0.9997、0.9999和0.9993,定量检出限均为0.5 μg/kg,回收率分别为93.57%~96.63%、92.35%~96.01%和91.66%~96.54%,该方法灵敏度高、重现性强,适用于猪肉组织样品中克仑特罗、沙丁胺醇及莱克多巴胺的确证检测。     

高效液相色谱法测定饲料中莱克多巴胺

本文对饲料中莱克多巴胺的高效液相色谱检测方法进行了研究,采用酸性甲醇-水提取饲料中的莱克多巴胺,用二氯甲烷和正己烷萃取净化,乙腈-水-冰乙酸-戊烷磺酸钠为流动相,反相高效液相色谱荧光检测法进行测定,激发波长226nm,发射波长305nm。方法的检测限为0.48μg/g,定量限为1.60μg/g,平均回收率为89.8%,变异系数为2.16%。     

固相萃取-气相色谱/质谱法同时检测动物组织中多种β-兴奋剂残留量的研究

建立了动物组织(肌肉、肝脏、肾脏)中妥洛特罗盐酸盐、异丙肾上腺素、硫酸特布他林、硫酸沙丁胺醇、盐酸克伦特罗、克伦潘特罗、波洛母特罗、盐酸羟苄羟麻黄碱、非诺特罗盐酸盐、莱克多巴胺等10种β-兴奋剂残留量的气相色谱-质谱法检测方法。样品经pH5.2乙酸钠溶液提取,提取液依次经乙酸乙酯-异丙醇(60∶40)混合溶剂和叔丁基甲醚-异丙醇(5∶1)萃取净化,再经Strata-X-C阳离子交换柱(500 mg,3cc)净化后,BSTFA∶TMCS(99∶1)衍生剂衍生,采用HP-5 MS(30 m×0.25 mm×0.25μm)色谱柱进行气相色谱-质谱法分析。10种β-兴奋剂类兽药检出限1μg/kg～5μg/kg,室内平均回收率59.1%～77.4%,变异系数(CV%)0.87～7.04。     

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.     

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.     

Feline intracranial neoplasia: retrospective review of 160 cases (1985-2001)

The purpose of this study was to determine the frequency of different tumor types within a large cohort of cats with intracranial neoplasia and to attempt to correlate signalment, tumor size and location, and survival time for each tumor. Medical records of 160 cats with confirmed intracranial neoplasia evaluated between 1985 and 2001 were reviewed. Parameters evaluated included age, sex, breed, FeLV/FIV status, clinical signs, duration of signs, number of tumors, tumor location(s), imaging results, treatment, survival times, and histopathologic diagnosis. Most of the cats were older (11.3 +/- 3.8 years). Primary tumors accounted for 70.6% of cases. Metastasis and direct extension of secondary tumors accounted for only 5.6 and 3.8% of cases, respectively. Twelve cats (7.5%) had 2 or more discrete tumors of the same type, whereas 16 cats (10.0%) had 2 different types of intracranial tumors. The most common tumor types were meningioma (n = 93, 58.1%), lymphoma (n = 23, 14.4%), pituitary tumors (n = 14, 8.8%), and gliomas (n = 12, 7.5%). The most common neurological signs were altered consciousness (n = 42, 26.2%), circling (n = 36, 22.5%), and seizures (n = 36, 22.5%). Cats without specific neurological signs were common (n = 34, 21.2%). The tumor was considered an incidental finding in 30 (18.8%) cats. In addition to expected relationships (eg, meninges and meningioma, pituitary and pituitary tumors), we found that lesion location was predictive of tumor type with diffuse cerebral or brainstem involvement predictive of lymphoma and third ventricle involvement predictive of meningioma.     

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.