氯霉素间接竞争ELISA(ciELISA)检测方法的建立

以人工合成的氯霉素－牛血清白蛋白（CAP－BSA）为包被抗原，氯霉素（CAP）为竞争半抗原，两者与一定量的抗CAP－McAb反应。结果表明，理想的包被抗原质量浓度为1．25mg/L，抗CAP－McAb稀释倍数为1∶12000，酶标二抗稀释倍数为1∶5000，最适检测范围为1－100μg/L，最小检测为0．1μg/L，批内和批间变异系数分别为3．62％和5．19％。得到回归方程（y=1.2730-0.6745x,r^2＝0．9779）和标准曲线，从而建立了快速定量测定CAP含量的间接竞争酶联免疫吸附试验（ciELISA）。     

直接竞争ELISA检测氯霉素残留的方法建立及初步应用

用混合酸酐法合成氯霉素的CAP抗原,用过碘酸钠氧化法合成CAP酶标记抗原,用ELISA方法对合成的CAP抗原、CAP酶标记抗原进行鉴定表明其与抗CAP单克隆抗体具有特异性反应。在此基础上建立了包被二抗的直接竞争ELISA方法。特异性试验结果表明,CAP琥珀酸酯、CAP琥珀酸钠盐的交叉反应率分别为107%、106.4%;甲砜霉素、氟甲砜霉素与CAP的交叉反应率小于0.016%;与其他结构类似物间未见交叉反应。该方法对CAP的检测限可达到0.1μg/L,IC50为11.6μg/L,线性范围0.1～100μg/L,批内变异系数小于11.5%,批间变异系数小于19.6%。对猪肉、鸡肉、蜂蜜分别添加1.0、3.0、10.0、30.0μg/L CAP标准品,回收率61.0%～102.0%,变异系数为6.6%～15.8%;对猪肉、鸡肉、蜂蜜中CAP的最低检测限分别为0.48、0.42、1.20μg/kg。     

磺胺二甲基嘧啶残留快速检测阻断ELISA试剂盒的研制及其性能测定

应用磺胺二甲基嘧啶(SM2)单克隆抗体(mAb)成功研制出SM2残留快速检测阻断ELISA试剂盒(SM2-Kit).研究结果表明,SM2-Kit的标准曲线呈典型的S型,相关系数R2=0.9911,符合4参数logit曲线拟合,线性检测范围为0.625μg/L～80μg/L,灵敏度为0.9 μg/L,半数抑制浓度(IC50)为5.82μg/L,检测限为1μg/L;饲料样、猪尿样的平均添加回收率分别为83.4%、89.5%,平均批内和批间变异系数均低于15%;SM2-Kit与磺胺甲基嘧啶的交叉反应率(CR%)为2.08%,与其它磺胺类药几乎没有反应性;基质对SM2-Kit的检测结果影响不大;试剂盒在4℃可保存6个月.     

鸡蛋中环丙氨嗪及其代谢物三聚氰胺残留检测超高效液相色谱-串联质谱法研究

建立了鸡蛋中环丙氨嗪及其代谢物三聚氰胺残留检测的超高效液相色谱-串联质谱（UPLC-MS／MS）方法。液相色谱条件：色谱柱为Waters BEH HILIC柱（50mm×2．1mm,1．7μm）;流动相为乙腈-0．01mol／L乙酸铵溶液,梯度洗脱;柱温30℃;流速0．3mL／min;进样量10μL。质谱条件为：电喷雾离子源（ESI^＋）,多反应监测（MRM）方式进行采集。结果表明：在2．5-100μg／L的基质匹配系列混合标准溶液内环丙氨嗪和三聚氰胺的相关系数R^2〉0．998;方法检测限为1μg/L,定量限为2．5μg／L;从10、50、100μg／kg三个添加浓度检测结果可以看出,方法的平均回收率为74．6％～91．4％,批内批间RSD值均〈15％。     

动物源食品中氯霉素、甲砜霉素、氟苯尼考及氟苯尼考胺残留检测－超高效液相色谱-串联质谱法研究

建立了动物源食品中氯霉素、甲砜霉素、氟苯尼考及氟苯尼考胺残留检测的超高效液相色谱-串联质谱（UPLC—MS／MS）分析方法。样品在碱性条件下用乙酸乙酯提取后,再用正己烷去除脂肪,浓缩后用BEH C18（50mm×2．1mm,1．7μm）色谱柱分离,以乙腈和水为流动相进行梯度洗脱,流速为0．3mL／min,多反应监测（MRM）模式检测。结果表明：四种药物在2—500μg／L的系列浓度范围内均呈良好线性关系,相关系数r均大于0．990。样品中氯霉素的检测限为0．1μg／kg,定量限为0．2μg/kg;甲砜霉素、氟苯尼考和氟苯尼考胺的检测限为0．5μg/kg,定量限为1μg／kg。本方法氯霉素在0．2～1μg／kg的添加浓度范围内,甲砜霉素、氟苯尼考及氟苯尼考胺在1—50μg／kg的添加浓度范围内平均回收率均为70％-120％,相对标准偏差（RSD）均小于20％。该方法具有简便快捷、灵敏度高、定性准确等特点。     

ELISA法测定牛奶和鸡肌肉中四环素类药物残留

以本实验室研制的四环素类药物多残留检测试剂盒为基础，建立了牛奶和鸡肉中四环素、土霉素、金霉素药和多西环素的ELISA检测方法。该方法对牛奶和鸡肉中四环素的检测限为7μg／L（μg／kg）左右。在牛奶和鸡肉中，4种四环素类药物100μg／L（μg／kg）浓度的添加回收率范围为43．6％～101．4％，批内变异系数小于25％，批间变异系数在30％以内。牛奶的临界值为39．5μg／L，鸡肉的临界值为35.3μg／kg。     

动物源性食品中泰乐菌素残留ELISA试剂盒的研制

采用杂交瘤技术,筛选并克隆出能够稳定分泌抗泰乐菌素（TYL）单抗的杂交瘤细胞株,免疫BALB／c小白鼠制备抗泰乐菌素单克隆抗体,建立泰乐菌素竞争ELISA检测试剂盒。结果表明,logit／log拟合标准曲线为y=-1．84x＋2．02,相关系数r=0．9944,线性检测范围为1．5～121．5ug／L,半数抑制浓度（IC50）为10.3ug／L,灵敏度为1．5ug／L,检测限为1．5～3．0ug／L;肌肉、肝脏、蜂蜜的添加回收率分别为64％～99％、61％～102％、60．5％～95％;平均批内和批间变异系数均小于10％;泰乐菌素与替米卡星（TIL）的交叉反应为40％,与其他类抗生素无交叉反应;此泰乐菌素试剂盒在4℃可保存6个月以上。本文建立的竞争ELISA检测方法可用于动物源性食品中泰乐菌素残留的定量检测。     

链霉素残留检测ELISA试剂盒的研制及应用

本研究采用EDC法人工合成链霉素抗原（SM—BSA）,免疫BALB／c小鼠,通过杂交瘤技术获得了分泌抗链霉素单克隆抗体的杂交瘤细胞株,建立了快速检测链霉素（SM）残留的酶联免疫方法,并成功研制了试剂盒。然后对其灵敏度、准确度、特异性、基质效应性等技术指标进行检测,同时应用该试剂盒对生长猪尿液中的残留情况进行检测。结果表明：除双氢链霉素外,该试剂盒与其它抗生素类药物均无交叉反应;线性检测范围为1～1289g／L,相关系数R^2=0．9251,灵敏度为0．45μg／L,半数抑制浓度（IC50）为7．769g／L,检测限为19g／L;猪尿样的平均添加回收率为84．1％;基质对该试剂盒的检测结果影响不大。该试剂盒具有快速、敏感、特异、简便等特点,适合于SM残留的快速检测,具有较高的推广应用价值。     

鸡组织中氯霉素残留的气相色谱-微电子捕获检测方法研究

建立了鸡肌肉和鸡肝脏组织中氯霉素残留的气相色谱-微电子捕获检测方法。用乙酸乙酯提取样品中的药物，正己烷脱脂，乙酸乙酯液-液分配，氮气吹干后，用Sylon BFT衍生化，进配有微电子捕获检测器（μECD）的气相色谱仪测定，外标法定量。鸡肌肉组织在0．1、0．5、1．0μg／kg三个添加水平，平均回收率为90．2％～94．3％，日内变异系数在4．5％-11．6％之间，日间变异系数在7．8％～14．3％之间，检测限0．05μg/kg，定量限0．10μg/kg。鸡肝脏组织在0．2、0．5、1．0μg/kg三个添加水平，平均回收率为82．9％～90．8％，日内变异系数在7．0％～11．2％之间。日间变异系数在7．9％～14．5％之间，检测限0．10μg/kg，定量限0．20μg/kg。     

气相色谱－质谱法测定猪尿中地西泮

建立了猪尿中地西泮的气相色谱-质谱（GC／MS）检测方法。样品经C18固相萃取柱净化后进行气相色谱-质谱测定。结果表明,方法定量限为0．5μg/L,线性范围为10～500μg/L。在三个添加浓度2、4、6μg/L水平上,地西泮的平均回收率为70％～120％,批内相对标准偏差〈20％、批间相对标准偏差〈12％。     

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.     

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.     

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.     

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.