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.     

浊度法测定酒石酸泰乐菌素可溶性粉效价研究

目的:建立浊度法测定酒石酸泰乐菌素可溶性粉效价的方法。方法:以金黄色葡萄球菌为试验菌,抗生素检定培养基Ⅲ号为试验用培养基,制备菌悬液。采用浊度法和管碟法对酒石酸泰乐菌素可溶性粉的效价测定进行比较,并对浊度法进行方法学验证。结果:用浊度法测定酒石酸泰乐菌素可溶性粉的效价,泰乐菌素的浓度范围在0.6-2.0 u/mL之间,其浓度对数与吸收度有良好的线性关系,相关系数r=0.999 0,平均回收率为100.3%,RSD为0.91%;用浊度法与管碟法测定结果无明显差异,方法学验证表明,浊度法测定酒石酸泰乐菌素可溶性粉效价的方法可行。结论:本方法具有可信限率低、灵敏度高、精密度高、快速简便等优点,可用于泰乐菌素及其制剂的效价测定。     

HPLC法分析猪肉中泰乐菌素残留

建立猪肉中泰乐菌素残留量的高效液相检测方法,为保障食品安全提供数据支撑。试料中残留的泰乐菌素用二氯甲烷提取,离心分层净化,高效液相色谱(紫外检测器)测定,外标法定量。结果显示,泰乐菌素在0.20～1.00μg/mL浓度范围内线性关系良好,相关系数r≥0.997 3;在100～500μg/kg浓度水平回收率范围为71.2%～86.2%;定量限为50μg/kg。经方法学验证,本方法专属性好、简便、快速、准确,适用于猪肉中泰乐菌素残留量的检测。     

伊维菌素纳米乳中伊维菌素含量HPLC检测方法的建立

建立了伊维菌素纳米乳中伊维菌素含量的高效液相色谱检测方法(HPLC).采用C18色谱柱(4.6×250 mm,5μm),以甲醇-乙腈-水(40:55:5)为流动相,流速1.0 mL/min,检测波长254 nm,进样量10μL,柱温25℃.伊维菌素浓度在4.6～92.0μg/mL时,其峰面积与浓度线性关系良好(r2=0...     

高效液相色谱荧光检测法检测Beagle犬血浆中伊维菌素的试验

建立一种灵敏、简便、可重复的高效液相色谱检测方法检测Beagle犬血浆中伊维菌素(Ivermectin,IVM)的含量。样品中加入内标多拉菌素(DRM),采用乙腈提取,涡旋振荡后高速离心,上清液于60℃N2吹干,衍生化后进样分析。色谱柱为ODS-2 Hypesil C18(250 mm×4.6 mm,5μm),检测器为荧光检测器,流动相为甲醇-乙腈-0.2%乙酸(55∶43∶2,V/V/V),流速为1 mL/min,激发波长365 nm,发射波长475 nm,柱温为35℃。测得DRM的保留时间为8.9 min,IVM保留时间为10.7 min。在0.25 ng/mL¹20 ng/mL的范围内,血浆药物浓度与峰面积之比呈良好的线性关系,其线性方程为:y=5.34e-003x+2.86e-003(n=10,R2=0.9998)。120 ng/mL、10 ng/mL、0.25 ng/mL三个浓度的添加回收率为83.01%120 ng/mL的范围内,血浆药物浓度与峰面积之比呈良好的线性关系,其线性方程为:y=5.34e-003x+2.86e-003(n=10,R2=0.9998)。120 ng/mL、10 ng/mL、0.25 ng/mL三个浓度的添加回收率为83.01%⁹1.75%,日内变异系数为3.75%91.75%,日内变异系数为3.75%⁶.45%,日间变异系数为3.26%6.45%,日间变异系数为3.26%⁸.86%,最低检测限为0.05 ng/mL。本方法操作简便,灵敏度高,可应用于Beagle犬血浆中伊维菌素的检测。     

高效液相色谱法测定赛鸽用复方吡喹酮胶囊中吡喹酮和伊维菌素的含量

用高效液相色谱法同时测定赛鸽用复方吡喹酮胶囊中吡喹酮和伊维菌素的含量.采用Nova-Pak C18柱(150 mm×3.9 mm,4 μm),以乙腈-甲醇-水(53:35:12)为流动相,流速为1.0 mL/min,检测波长254 nm,柱温25℃.在此色谱条件下,吡喹酮和伊维菌素的分离良好,吡喹酮和伊维菌素分别在511～1 534μg/mL和10.1～30.6μg/mL浓度范围内峰面积与浓度呈良好的线性关系(r＞0.999).按外标法以峰面积计算进行测定,吡喹酮和伊维菌素的平均回收率分别为99.9%和98.3%,RSD分别为0.3%和0.6%(n=9).本方法简便、快速、准确,适用于赛鸽用复方吡喹酮胶囊中吡喹酮和伊维菌素含量的测定.     

ELISA方法检测牛组织中的阿维菌素类药物残留

建立一种间接竞争ELISA方法,检测牛组织中的阿维菌素类药物(Avermectins,AVMs)残留。该方法可同时检测牛肝脏和肌肉中的阿维菌素、伊维菌素和埃普里诺菌素残留。标准曲线:y=-45.613x+81.191,R2=0.9951,IC50=4.8ng/mL,线性范围为1.1ng/mL²1.9ng/mL。空白牛肝脏组织中以20、50ng/mL和100ng/g浓度添加时,AVMs回收率为53.8%21.9ng/mL。空白牛肝脏组织中以20、50ng/mL和100ng/g浓度添加时,AVMs回收率为53.8%⁸0.4%,变异系数为3.4%80.4%,变异系数为3.4%¹7.9%;空白牛肌肉组织中以5、10ng/mL和20ng/g浓度添加时,AVMs回收率为70.9%17.9%;空白牛肌肉组织中以5、10ng/mL和20ng/g浓度添加时,AVMs回收率为70.9%¹08.6%,变异系数为3.7%108.6%,变异系数为3.7%¹7.1%。     

液相色谱串联质谱法测定鸡蛋、牛奶和羊奶中泰乐菌素A残留的研究

建立了鸡蛋、牛奶和羊奶中泰乐菌素A残留的液相色谱-串联质谱法.样品经乙腈提取后,Prime HLB固相萃取柱净化,以0.1％甲酸水和乙腈为流动相,液相色谱-串联质谱法测定,内标法定量.试验结果表明:泰乐菌素A在1～100 ng/mL浓度范围内线性关系良好,相关系数r大于0.99;在鸡蛋、牛奶和羊奶中的检测限为2 ng/...     

双波长紫外分光光度法测定酒石酸泰乐菌素-盐酸多西环素可溶性粉的含量

建立了双波长紫外分光光度法同时测定酒石酸泰乐菌素-盐酸多西环素可溶性粉中酒石酸泰乐菌素和盐酸多西环素含量的检测方法。结果显示，吸收度与浓度呈良好线性关系。酒石酸泰乐菌素的平均回收率为99．90％，RSD为0．42％n=5）；盐酸多西环素的平均回收率为100．07％，RSD为0．74％（n=5）。     

复方泰乐菌素注射液防治猪气喘病的疗效观察

通过复方泰乐菌素注射液对仔猪气喘病例的治疗来评价复方泰乐菌素注射液对防治猪气喘病的应用效果,为临床使用提供依据。结果表明:复方泰乐菌素注射液治疗猪气喘病的效果明显,推荐剂量按体重0.1mL/kg肌肉注射。     

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.     

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.     

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.     

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.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein     

Avian brood parasitism — a growing research area in behavioral ecology (part Ⅱ)

正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments in