奶牛用利福昔明子宫注入剂有关物质反相高效液相色谱检测方法的建立及应用

本试验旨在建立利福昔明有关物质的检测方法。采用反相高效液相色谱法,紫外检测器进行检测,采用WondaSil C18-WR 250 mm×4.6 mm 5 μm色谱柱,柱温:40 ℃,流动相及其比例为:V（甲醇） ∶V（乙腈）∶V（3.16 g/L甲酸铵,浓氨水调pH至7.2）=31.5∶31.5∶37,检测波长276 nm。采用面积归一化法计算利福昔明子宫注入剂的检测限、定量限及其浓度;考察了方法精密度、线性相关性及有关物质专属性,并通过极端条件的破坏、有关物质的含量、分离度等对主成分峰面积降解程度进行了比较。利福昔明子宫注入剂主成分峰在浓度为40~150 μg/mL的范围内,峰面积与浓度呈现良好的线性关系（R²=0.9998）,其有关物质浓度对峰面积线性回归方程为y=23 510x+7 182,其进样精密度RSD为0.13%,方法精密度RSD为0.46%,制剂一定时间内经过强酸、强碱、氧化、高温条件破坏后均有不同程度降解,以破坏前的样品主成分含量为100.00%,氧化破坏和高温破坏主成分降解达13%,酸、碱破坏主成分降解在18%左右,主成分峰保留时间在以上4种条件破坏前后一致,且主成分峰与杂质峰之间及杂质峰与杂质峰之间分离度良好（主成分峰与杂质峰之间分离度均大于1.5,杂质峰与杂质峰之间分离度均大于1.2）。本试验建立的利福昔明子宫注入剂有关物质检测方法操作简便,专属性和重复性好,可适用于利福昔明子宫注入剂有关物质的测定。     

利福昔明子宫注入剂稳定性及其对家兔阴道黏膜刺激性研究

为研究利福昔明子宫注入剂的稳定性,从而初步确定其保质期,本试验取3批利福昔明子宫注入剂进行稳定性试验考察,包括影响因素、高温加速及长期稳定性,利用高效液相色谱法测定试验过程中利福昔明含量及有关物质的含量,从而初步确定利福昔明子宫注入剂的保质期。根据相关技术指导原则对家兔进行阴道刺激性试验。稳定性试验结果表明,根据面积归一化法计算有关物质的含量均不超过3%,注入剂的性状、沉降、粒度未发生明显变化,主成分利福昔明的含量变化在拟定标示量90.0%~110.0%范围内,从而确定本品的有效期为2年。家兔阴道刺激性试验结果显示,利福昔明子宫注入剂给药部位（阴道）和生理盐水对照组给药部位都没有出现红斑和水肿,刺激强度的评分为0;试验组和对照组的阴道黏膜没有出现明显的充血、水肿及异常分泌物流出的现象,阴道黏膜刺激指数为0.25。因此,利福昔明子宫注入剂对家兔的阴道无刺激性。本品的临床安全性良好,可进一步推广使用。     

利福昔明子宫注入剂稳定性及其对家兔阴道黏膜刺激性研究

为研究利福昔明子宫注入剂的稳定性,从而初步确定其保质期,本试验取3批利福昔明子宫注入剂进行稳定性试验考察,包括影响因素、高温加速及长期稳定性,利用高效液相色谱法测定试验过程中利福昔明含量及有关物质的含量,从而初步确定利福昔明子宫注入剂的保质期。根据相关技术指导原则对家兔进行阴道刺激性试验。稳定性试验结果表明,根据面积归一化法计算有关物质的含量均不超过3%,注入剂的性状、沉降、粒度未发生明显变化,主成分利福昔明的含量变化在拟定标示量90.0%～110.0%范围内,从而确定本品的有效期为2年。家兔阴道刺激性试验结果显示,利福昔明子宫注入剂给药部位(阴道)和生理盐水对照组给药部位都没有出现红斑和水肿,刺激强度的评分为0;试验组和对照组的阴道黏膜没有出现明显的充血、水肿及异常分泌物流出的现象,阴道黏膜刺激指数为0.25。因此,利福昔明子宫注入剂对家兔的阴道无刺激性。本品的临床安全性良好,可进一步推广使用。     

高效液相色谱法测定利福昔明混悬乳剂的含量

建立了测定利福昔明混悬乳剂含量的高效液相色谱法(HPLC)。采用C18色谱柱(4.6 ×150 mm,5 μm),以甲醇-乙腈-0.075 mol/L磷酸二氢钾溶液-1 mol/L柠檬酸溶液(32：28：25：4)为流动相,流速1.0 ml/min,检测波长236 nm,进样量20 μL,柱温25℃。利福昔明浓度在5～100 μg/mL时,其峰面积与浓度线性关系良好(r2=0.9996),无杂质干扰,稳定性高,平均回收率99.1％。本操作方法简便,分析快速,结果准确,适用于利福昔明混悬乳剂的含量测定。     

高效液相色谱法测定美洛昔康内服混悬液中美洛昔康的含量

建立高效液相色谱法测定美洛昔康内服混悬液的含量。采用ODSC18色谱柱(150 mm×4.6 mm,5μm),以0.1%磷酸二氢钾溶液和甲醇进行梯度洗脱,检测波长为360 nm,进样量为20μL。实验结果表明,美洛昔康在37.5¹50.0μg/mL范围内线性良好(r=0.999 9),方法的平均回收率为100.5%,相对标准偏差(RSD)为1.4%(n=9);以信噪比(s/n)≥3为检出限,信噪比(s/n)≥10为定量限,检测限和定量限分别为18.8μg/mL和75.0μg/mL。本法应用于美洛昔康内服混悬液中美洛昔康含量的测定,结果准确可靠。     

HPLC法测定猪体内双氯芬酸的血药浓度

建立猪血浆中双氯芬酸含量的HPLC测定法。猪血浆中双氯芬酸采用正己烷-异丙醇混合溶液(90∶10,V/V)提取,HPLC紫外检测器检测。色谱柱为C18柱,流动相为甲醇-15g/L乙酸水溶液(80∶20,V/V),测定波长为276nm。外标法定量。结果表明,血浆中杂质不干扰双氯芬酸的测定,双氯芬酸血药浓度在0.025μg/mL~20.0μg/mL范围内线性关系良好(R2=1),最低定量限为0.05μg/mL,高、中、低空白血浆添加样品浓度的日内变异系数和日间变异系数分别小于4%和6%,回收率为85%~97%。结果表明,该方法适用于猪血浆中双氯芬酸含量的测定,可用于含双氯芬酸钠的制剂在猪体内的药物代谢动力学和生物利用度研究。     

牛奶中利福昔明残留消除规律研究

为研究新型奶牛干乳期乳房注入剂利福昔明在牛奶中的残留消除规律,在常规饲养条件下,选择处于干乳期的12头健康奶牛分为2组(每组6头),在预产期前60天,按推荐剂量(100mg)及2倍推荐剂量(200mg)两种剂量通过乳房注入方式给药,在产犊泌乳后的12、24、36、48、60和72h共6个时间点采集奶样,用超高效液相色谱-串联质谱法检测。液相条件：色谱柱为BEH C18(50?2.1mm,1.7μm),0.1%甲酸乙腈和0.1%甲酸水为流动相进行梯度洗脱。质谱条件：ESI＋离子源,MRM方式采集。结果表明：推荐剂量组12h时6头奶牛有2头检出利福昔明,残留量分别为2.84和4.50μg/kg;24h时已全部检不出药物。2倍推荐剂量组12h时6头奶牛均检出利福昔明,残留量仅在1.56~10.2μg/kg之间,24h时有2头检出,残留量分别为1.41和1.28μg/kg,36h时全部检不出药物。两组检出的残留量均远低于欧盟规定的牛奶中最高残留限量60μg/kg。因此,实验用12头干乳期奶牛使用利福昔明乳房注入剂后在产犊泌乳时牛奶中的休药期均为零。     

高效液相色谱法测定麻杏石甘颗粒中盐酸麻黄碱含量

为完善麻杏石甘颗粒质量标准,采用高液相色谱法对麻杏石甘颗粒中盐酸麻黄碱的含量测定进行研究。采用Thermo scientific BDS C18色谱柱(4.6 mm×250 mm,5μm),流动相为乙腈-0.1%磷酸溶液(含0.1%三乙胺)(3∶97),检测波长207 nm,流速1.0 mL/min,柱温30℃,进样量10μL。结果表明,盐酸麻黄碱进样浓度在5～60μg/mL范围内,峰面积与盐酸麻黄碱含量呈良好线性关系(R²=0.9999)。样品平均回收率为96.62%(n=6),RSD为1.30%。本方法简便、准确度高、重复性好、耐用性强,为进一步提高该制剂的质量标准,保证临床效果,提供了检测依据。     

高效液相色谱法检测阿司匹林丁香酚酯含量

为了评价阿司匹林丁香酚酯的纯度,用高效液相色谱法对阿司匹林丁香酚酯的含量测定进行了方法学研究。试验采用Agilent Technologies 1290高效液相色谱仪,Hypersil ODS色谱柱,乙腈-水(65∶35)为流动相,流速1 mL/min,柱温35℃,检测波长为279 nm。结果:该方法测定阿司匹林丁香酚酯含量系统适应性好,检测限为0.2μg/mL,定量限为0.7μg/mL;线性关系良好,线性回归方程为:y=8.930x-7.450,R~2=0.999 0;平均回收率为100.07%;重复性良好,RSD为0.72%;系统耐用性中各水平下的峰面积、理论塔板数和分离度均符合标准;测定3批样品含量分别为98.4%、99.3%和99.8%。研究表明本方法专属性好,线性关系符合规定,准确度,重复性测定结果在规定范围内,系统耐用性好,3批样品含量符合标准。     

高效液相色谱法测定埃普利诺菌素注射液的含量

本文描述了用高效液相色谱法(HPLC)测定埃普利诺菌素注射液含量的方法研究。色谱条件:流动相为甲醇∶水(90∶10),流速1.0mL/min,进样量50μL,柱温为室温,检测波长245nm。样品回收率为(98.72±0.28)%。在5～200μg/mL浓度范围内,检测样品的中间精密度:批内变异系数为0.54%～0.80%,批间变异系数为0.28%～1.06%。本方法可用于埃普利诺菌素注射液的含量检测。     

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.     

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