GC法检测泰乐菌素中残留乙酸乙酯的含量

采用气相色谱(GC)法检测泰乐菌素中残留乙酸乙酯的含量,控制乙酸乙酯在药品中的溶剂残留.水做溶剂,正丁醇为内标物,DB-WAX30 m×0.25 mm I.D.,0.25 μm毛细管柱,氮气为载气,火焰离子检测器,柱温75℃,内标法检测泰乐菌素中乙酸乙酯的含量.检测乙酸乙酯的回收率为95.55％ ～ 105.00％,达到验证要求,在4～20 μg/mL浓度范围内线性关系良好(r =0.9999).该方法简便、准确、分离度好,可用于检测泰乐菌素原料中乙酸乙酯的溶剂残留.     

高效液相色谱法测定鸡肝组织中的氢溴酸常山酮残留

用高效液相色谱法测定鸡肝组织中常山酮的残留量.色谱柱为Kromasil C18(250 mm×4.6 HDM, 5 μm);流动相为乙腈-醋酸盐缓冲液(0.25 mol/L,pH 4.3)-水(5∶3∶12),检测波长243 nm,流速2.0 mL/min.该方法线性范围为0.10～5.00 mg/mL,r=0.999 9,平均回收率达到77.0%～80.3%,RSD<4.3%.该方法灵敏、准确、重现性好.     

基质固相分散萃取-气相色谱法检测水产品中7种多氯联苯残留

建立了水产品中7种多氯联苯残留的气相色谱检测方法。采用HP-5石英毛细管柱（30 m×0.32 mm×0.25μm）以及气相色谱仪（带电子捕获检测器）在程序升温的条件下分离水产品中7种多氯联苯残留。方法线性范围为1～180 ng/mL,相关系数均大于0.999,定量限为0.5μg/kg,检测限为0.3μg/kg。该方法采用正己烷/二氯甲烷（9∶1）提取,佛罗里硅土分散固相萃取、净化,结果准确可靠,重复性好,回收率为84.7%～112%,相对标准偏差为0.79%～8.88%,可满足实验室对水产品中7种多氯联苯快速分析的需要。     

毛细柱气相色谱法测定饲料中丙酸及丙酸盐

实验建立了气相色谱法测定饲料中丙酸及丙酸盐的分析方法。样品经盐酸酸化后,丙酸盐转化为丙酸,乙醚提取,毛细管柱(HP-FFAP,30 m×0.32 mm×0.25μm)分离,进行FID检测器检测。结果表明,方法的线性范围为5.0~500 mg/L(R=0.9993),检出限为0.77 mg/kg,丙酸的回收率为87.2%~93.4%,相对标准偏差为1.7%~3.2%。     

凝胶渗透色谱净化-气相色谱分离同时测定饲料中30种有机磷农药残留

文中建立了凝胶渗透色谱净化-气相色谱法同时测定饲料中敌敌畏、乐果等30种有机磷农药残留的方法。饲料样品用乙腈体系提取,采用凝胶色谱柱净化,毛细管色谱柱分离(DB-50+,30 m×0.25 mm×0.25μm),火焰光度检测器(FPD)检测,外标法定量。其方法检测限为5.6~54μg/kg,三水平添加回收率为71.3%~114.1%,RSD为0.3%~14.8%。方法简便、准确,并能满足饲料中多种有机磷农残测定的需要。     

气相色谱法测定饲料中的特丁基对苯二酚

利用乙酸乙酯直接提取猪饲料和鱼粉中的抗氧化剂特丁基对苯二酚(TBHQ),并用气相色谱法 测定其含量.采用安捷伦ECTM-1毛细管柱(30 m×直径0.25 mm),氢火焰离子化检测器,外标法定量测量,试验结果表明:标准曲线在10～250μg/mL范围内相关系数＞0.999 3,最低检出限为0.002 g/kg,样品加标回收率为95 %～103%,标准偏差分别为2.49%和1.88%,方法具有操作简便、灵敏度高和重现性好等优点.     

鸡肉和鸡肝中有机磷农药残留的检测

试验研究了鸡肌肉和肝脏组织中10种有机磷农药残留的气相色谱－火焰光度检测方法。用丙酮和二氯甲烷混合溶剂提取,磷酸缓冲溶液沉淀蛋白质等,凝胶色谱法去除剩余油脂等,用配有火焰光度检测器的气相色谱仪检测,外标法定量。在0.05、0.2、1 mg/kg添加水平,肌肉组织的平均添加回收率在74.2%～108.0％,变异系数在1.6%～17. 3%之间。肝脏组织的平均添加回收率在69.8%~103.0％,变异系数在1.0%～16.0 %之间。     

气相顶空法检测c-met抑制剂中异戊醇的残留

目的:用气相顶空外标法检测药物中的异戊醇残留。方法:将样品溶于N,N-二甲基咪唑啉酮,顶空90℃保持30 min,采用毛细管气相色谱柱HP-INNOWax(30 m×250μm×0.25μm);FID检测器;载气为氮气;流速3 mL/min;检测器温度250℃;进样口温度200℃;分流比5/1;程序升温:起始温度40℃,保持3 min,再以5℃/min温至90℃,保持5 min,最后以20℃/min升温至230℃,保持5 min。结果:异戊醇的线性范围为1.05~67.04μg/mL(R~2=0.998 2),定量限:1.05μg/mL,回收率为95.79%~98.78%,精密度1.0%,溶液稳定性符合设计要求。结论:所建立的气相顶空法灵敏准确、精密稳定,适合对药品中异戊醇的检测研究。     

气质联用快速检测饲料中29种农药残留

建立快速测定饲料中的29种农药多残留的方法(QuEChERS).该方法以乙腈作提取剂, 以PSA(伯仲氨基柱)和C18作分散净化剂,用气相色谱-质谱在选择离子监测模式下检测,并使用以内标法定量, 29种农药在0.01～1 μg/mL(甲胺磷和乙酰甲胺磷在0.02～2 μg/mL,氯氰菊酯和溴氰菊酯在0.05～2 μg/mL)的线性良好,3个添加水平的回收率分别为66 %～119 %、63 %～120 %和68 %～98 %,检测限为0.4～33.1 μg/kg.     

毛细管气相色谱法测定维生素E原料含量

用毛细管气相色谱法测定饲料添加剂维生素E原料中维生素E含量.以正三十二烷为内标物,采用DB-1毛细管柱(30 m×0.25 mm×0.25um),FID检测器;氮气为载气;柱温为280～290℃,检测器温度为290～300℃;进样口温度为290-300℃;无分流进样.在此色谱条件下,维生素E和内标物正三十二烷分离良好,在0.994～4.013 mg/mL浓度范围内呈良好线性关系,r=0.9998,经方法评估函数的评价表明,方法不存在恒定系统误差和相关性系统误差,方法准确性较好.本法操作简便易行,系统适用性良好,适用于饲料添加剂维生素E原料中维生素E含量测定.     

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.