牛肉组织中玉米赤霉醇及相关物残留的气相色谱-质谱法测定

建立了能够同时检测牛肉组织中玉米赤霉醇（又名α-玉米赤霉醇）及3种相关物（β-玉米赤霉醇、玉米赤霉酮和α-玉米赤霉烯醇）残留的气相色谱-质谱联用法。样品均质后,用甲醇提取样品中的待测物,浓缩,用水稀释后,乙酸乙酯萃取,浓缩。用氢氧化钾溶液溶解,正己烷去脂,乙醚萃取,氨基固相萃取柱净化,衍生化后,用气相色谱-质谱联用仪检测,外标法定量。玉米赤霉醇、β-玉米赤霉醇、玉米赤霉酮和α-玉米赤霉烯醇线性范围均为0.5-10.0 ng/mL,检测限均为1.0 ng/g,在添加5.0 ng/g时,回收率为71.5%-81.4%,变异系数为1.4%-5.0%。     

鸡肌肉组织中氯霉素残留ELISA检测方法的研究

本文利用活化酯法合成了氯霉素抗原 ,作为免疫原免疫新西兰大耳白兔得到氯霉素的多克隆抗体 ,建立了氯霉素间接竞争酶联免疫检测方法 ,进行了药物交叉反应性试验 ,并对鸡肌肉进行添加回收试验。结果显示抗体效价可达 1∶ 6 4 0 0 0 0 ,IC50 为 1.3ng/ ml,最低检测限达到 0 .0 5 ng/ ml,线性检测范围为 0 .1～ 36 .4 5 ng/ ml。在 0 .5、1、2 .5、5 ng/ g浓度水平添加到鸡肌肉组织中 ,测得回收率为 5 5 .4 %～ 119.0 % ,变异系数为 4 .3%～ 10 .4 %。该 EL ISA方法快速、灵敏、方便 ,满足了氯霉素残留检测的要求。     

饲料中玉米赤霉醇ELISA检测试剂盒的研制与应用

目的：建立快速、有效检测植物性食品中ZER的残留量。方法：应用间接竞争ELISA法建立玉米赤霉醇单克隆抗体快速检测植物性食品中ZER含量的半定量检测。同时对该ELISA试剂盒进行了调试。结果：实验以人工合成的ZER为包被原,ZER为竞争半抗原,两者与一定量的抗玉米赤霉醇单克隆抗体反应,建立检测ZER的ELISA方法。其最适包被浓度为1：5000,抗体最适工作浓度为1：5000,酶标二抗的最适工作浓度为1：5000。试剂盒检测限为0.5ng/ml,添加回收率在70.0豫～116.0豫之间,变异系数小于20豫,在2～8℃条件下可保存3个月。     

间接竞争ELISA法检测玉米中ZEN的提取方法研究

应用抗玉米赤霉烯酮单克隆抗体(ZEN-McAb)建立间接竞争ELISA,用以检测玉米中的玉米赤霉烯酮(ZEN)。检测限为1ng/ml,检测范围为1～20ng/ml。在提取玉米赤霉烯酮的过程中,提取液中的甲醇含量对检验结果的影响很大。当提取液中甲醇含量为60%时,加标回收率最理想,平均回收率为92.4%。     

玉米副产物中玉米赤霉烯酮的ELISA测定

通过试验研究了酶联免疫吸附法在玉米及其副产物中玉米赤霉烯酮检测的应用。在优化了样品前处理后,其方法灵敏度为1.0ng/ml,线性范围为0～20ng/ml,回收率为70.3%～90.9%,并用该法测定了24份玉米副产物样品,检出率达100%,阳性率为37.5%,其结果表明该方法快速、灵敏、准确,有较好的实用性。     

荧光定量法检测饲料中玉米赤霉烯酮

试验建立了饲料中玉米赤霉烯酮荧光定量检测方法。结果表明:玉米赤霉烯酮在0.1～1.6 mg/L浓度范围内线性关系良好,r2=0.999 0。以配合饲料、浓缩饲料、预混料为添加基质,其回收率在80%～120%,检出限为0.1 mg/L。该方法灵敏度高、操作简单、结果准确。     

饲料中玉米赤霉醇、玉米赤霉酮和己烯雌酚的测定——超高效液相色谱-串联质谱法

本文建立了饲料中玉米赤霉醇、玉米赤霉酮和己烯雌酚的UPLC-MS/MS分析方法。饲料样品经正己烷-乙酸乙酯溶液(V/V=85:15)提取,离心后提取液氮气吹干,正己烷溶解后经-OH净化柱净化,用50%乙腈水溶液洗脱,UPLC-MS/MS分析。结果表明,3种目标化合物药物在10.0~50.0μg/kg浓度范围内线性关系良好,r≥0.99。以玉米、DDGS、配合饲料、精料补充料等为添加基质,其回收率在61.7%~99.4%之间,检出限为10μg/kg,定量限为20μg/kg。说明本方法灵敏度高,专属性好,操作简单,结果可靠,可满足饲料中玉米赤霉醇、玉米赤霉酮和己烯雌酚的分析检测。     

抗玉米赤霉烯酮单克隆抗体的制备及ELISA检测试剂盒的研制

制备并鉴定抗玉米赤霉烯酮(ZEN)单克隆抗体杂交瘤细胞株,研制检测谷物中ZEN的ELISA检测试剂盒。将ZEN肟化成ZEN-6-CMO,ZEN-6-CMO在DCC与NHS作用下与牛血清白蛋白(BSA)或卵清白蛋白(OVA)偶联合成完全抗原。以ZEN-6-CMO-BSA为抗原,免疫BALB/c小鼠,用ELISA筛选并建立分泌抗ZEN抗体的杂交瘤细胞株。测定单抗免疫球蛋白亚类、单抗效价及特异性。在ZEN单克隆抗体(Z9C3)的基础上,用间接竞争ELISA研究试剂盒的各项指标。试验结果表明:建立了2株稳定分泌抗ZEN抗体的杂交瘤细胞株(Z9C3和Z7E6),该细胞株所分泌的单隆抗体Ig亚类均为IgG1,ELISA检测结果表明:抗ZEN抗体可与ZEN发生特异性反应,IC50为3ng/mL和1.3ng/mL,该抗体与玉米赤霉醇(ZEL)的交叉反应分别为15.9%和9.8%。试剂盒最低检出质量浓度为0.5ng/mL,标准曲线的线性范围为0.5～50ng/mL;对玉米和小麦的平均添加回收率分别是92.5%和91.7%,变异系数分别是8.5%和10.5%。     

动物性食品中玉米赤霉烯酮残留的LC-MS/MS法测定

建立了用液相色谱-串联质谱法(LC-MS/MS)测定动物性食品中玉米赤霉烯酮毒素残留量的检测方法。样品(猪肉、猪肝、鸡肉)经乙腈∶水(75∶25,V/V)提取,正己烷除脂,Bond Elut Mycotoxin萃取柱净化,0.1%甲酸水溶液-乙腈(75∶25,V/V)洗脱,采用质谱电喷雾电离源,正离子扫描,多反应监测模式(SRM)监测,外标法定量。该方法玉米赤霉烯酮标准曲线的线性回归系数在0.9983~0.9998之间,线性范围1~100 ng/m L,方法检测限均为1.0 ng/g,定量限为5.0 ng/g,回收率在76.1%~87.22%之间,相对标准偏差2.33%~8.36%,变异系数(CV)在17%以内,可有效实现动物性食品中玉米赤霉烯酮毒素残留检测。     

牛奶中氟喹诺酮类药物残留量检测方法研究

建立了牛奶中5种氟喹诺酮类药物(达氟沙星、恩诺沙星、环丙沙星、沙拉沙星和二氟沙星)残留检测的高效液相色谱-荧光检测法.结果表明,环丙沙星、恩诺沙星、沙拉沙星、二氟沙星在5～300 ng/mL,达氟沙星在1～60 ng/mL浓度范围内,呈良好的线性关系,r均大于0.999 9.方法最低检测限环丙沙星、恩诺沙星、沙拉沙星、二氟沙星为5 ng/mL,最低定量限为10 ng/mL.达氟沙星最低检测限为1 ng/mL,最低定量限为2 ng/mL.环丙沙星、恩诺沙星、沙拉沙星、二氟沙星在10、50、100 ng/mL三种浓度添加水平上,平均回收率为70%～94%,达氟沙星在2、10、20 ng/mL三种浓度添加水平上,平均回收率为73%~88%.批内、批间RSD均小于11%.     

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.     

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.     

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.     

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.     

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.     

A brief history of the prevention of infectious diseases by immunisations

Infectious diseases have always been a terrible scourge for humans. The appearance of these plagues, as they were called without distinction, was generally connected to various conditions: asters, climatic changes or religious reasons. The concept of contagious, and then infectious, diseases came slowly. Variolation, i.e. transmission of ‘virulent’ matter to induce a natural disease and the immunity against it, was brought from Constantinople to England by Lady Montague, in 1721. This ‘variolation’ technique was also often performed in veterinary medicine against diseases like sheep-pox or pleuropneumonia. As ‘vaccination’ is the term generally accepted for ‘immunisation’, variolation can be the word designating such a technique. The second period of the history of immunisation began, in 1880, with the studies of Pasteur and his collaborators. A great number of bacterial vaccines were developed: dead, live but attenuated or only parts of pathogens. The viruses were produced in animals, then in eggs and at last, in tissue cultures. Second generation vaccines appeared with genetic engineering: recombinant vaccines, vector vaccines, nucleic acids vaccines, and markers vaccines, among others. These novel technologies can permit the development of new ones and improve the quality of the vaccines already existing.