HPLC-PDA法同时测定硫酸新霉素可溶性粉中非法添加4种化学药物

建立同时测定硫酸新霉素可溶性粉中非法添加甲硝唑、水杨酸、乙酰甲喹、甲氧苄啶的HPLC-PDA方法。样品用甲醇提取,经C18柱分离,以磷酸盐缓冲液-甲醇为流动相洗脱,流速为1.0 mL/min,采用二极管阵列检测器进行全波长(200～400 nm)扫描,提取波长为230 nm。检查保留时间、峰纯度和光谱相似度,对非法添加化学药物进行确证。结果表明,4种化学药物在0.01～0.12 mg/mL的范围内线性关系良好(r≥0.9998);回收率在98.0％～99.9%之间,RSD≤1.0％,检出限为1～5 g/kg。该检测方法专属性强、操作简便,可用于硫酸新霉素可溶性粉中非法添加4种化学药物的测定。     

阿莫西林可溶性粉中非法添加氟苯尼考的HPLC-PDA检测方法的建立

建立了阿莫西林可溶性粉中非法添加氟苯尼考的HPLC-PDA检测方法。采用十八烷基键合硅胶为填充剂;以乙腈-水为流动相,流速1.0 mL/min;二极管阵列检测器,提取波长为224 nm。通过液相色谱保留时间、峰纯度检查和光谱相似度检查对非法添加物进行确证。结果表明,该色谱条件下,氟苯尼考与其他物质分离良好,在1~200 μg/mL浓度范围内线性关系良好（r2=1.000）,回收率在98.1%~103.2%之间,RSD≤0.6%,检测限为0.4 g/kg。该方法操作简便、快速、灵敏度高,可用于阿莫西林可溶性粉中非法添加氟苯尼考的测定。     

硫酸安普霉素可溶性粉中非法添加乙酰甲喹的HPLC-PDA检测方法的建立

为检测硫酸安普霉素可溶性粉中非法添加的乙酰甲喹,以十八烷基硅烷键合硅胶为填充剂,磷酸盐缓冲液(取磷酸二氢钠3.0 g,加水1000 m L使溶解,加三乙胺0.5 m L,用饱和氢氧化钠溶液调节p H值至7.0)-甲醇为流动相,二极管阵列检测器(PDA),建立了HPLC-PDA检测方法,并采用峰纯度检查和光谱相似度检查辅助对照品比对方法,对非法添加药物进行确证。在此液相色谱条件下,乙酰甲喹与其他物质峰分离良好。按外标法以峰面积计算,乙酰甲喹的平均回收率为98.1%,RSD为0.3%。该检测方法简便、准确、可靠,可用于测定硫酸安普霉素可溶性粉中非法添加的乙酰甲喹。     

超高效液相色谱-串联质谱法测定鸡蛋中四环素类、喹诺酮类、磺胺类残留量

建立了超高效液相色谱-串联质谱法，测定了鸡蛋中四环素类、喹诺酮类、磺胺类11种抗生素残留量。采用1%酸化乙腈溶液提取，应用超高效液相色谱-串联质谱仪检测，定量方法采用外标法。鸡蛋中上述11种药物在5～100ng/mL的浓度范围内呈现良好的线性关系，鸡蛋中的检测限为1.0μg/kg，定量限为2.0μg/kg，在1.0～50μg/kg添加浓度范围内的回收率为70.2%～90.2%，批内与批间RSD值均<7.9%。     

五种兽药中非法添加喹乙醇和乙酰甲喹的HPLC-PDA检测方法的建立

建立了高效液相色谱法测定五种制剂中非法添加喹乙醇与乙酰甲喹的方法。以十八烷基键合硅胶为填充剂,乙腈-0.01mol/L磷酸二氢钾(pH 6.0)为流动相,二极管阵列检测器进行全波长(200～400nm)扫描,检测波长为260nm,并采用峰纯度检查和光谱相似度检查辅助对照品比对方法,对非法添加药物进行确证。结果表明,该色谱条件下喹乙醇、乙酰甲喹与其他物质峰分离良好。喹乙醇、乙酰甲喹在0.5～200μg/mL浓度范围内线性良好,回收率在91.1%～105.7%之间,RSD≤3.1%,喹乙醇、乙酰甲喹的检测限分别为1.0mg/g、2.5 mg/g。     

高效液相色谱-二极管阵列检测法测定乳酸环丙沙星可溶性粉中非法添加甲硝唑和替硝唑的研究

为确证乳酸环丙沙星可溶性粉中的非法添加物,采用高效液相色谱-二极管阵列检测器(HPLC-DAD)的谱库匹配,推断出疑似添加物为甲硝唑,从而建立检测乳酸环丙沙星可溶性粉中违规添加甲硝唑和替硝唑的高效液相色谱法。采用Agilent Eclipse XDB-C18色谱柱(250 mm×4.6 mm,5μm),流动相为甲醇-水(20∶80,V∶V),流速为1.0 mL/min,柱温30℃,用二极管阵列检测器进行扫描,扫描范围为190～400 nm,检测波长为320 nm。该色谱条件下甲硝唑和替硝唑与其他物质峰分离良好。甲硝唑和替硝唑在0.5～100μg/mL浓度范围内线性良好,在2.5 mg/g、5.0及10.0 mg/g 3个添加浓度下,加样回收率为99.5%～100.2%,RSD小于1.5%,检测限为2.5 mg/g。本方法简便快捷、准确度和灵敏度高,能满足非法添加物检测的要求。     

UPLC-MS/MS法测定氟喹诺酮类药物可溶性粉中非法添加物利巴韦林

建立了氟喹诺酮类药物可溶性粉中非法添加物利巴韦林检测的UPLC-MS/MS方法。样品经提取稀释后,采用ACQUITY UPLCR BEH amide色谱柱为分离柱,质谱正离子扫描测定。结果显示,利巴韦林在1~50 ng/mL的范围内线性关系良好（R2=0.9984）;样品检出限为0.5 mg/g,定量限为2 mg/g。在40、50、60mg/g添加水平的回收率为90%～110%,批内批间变异系数均小于10%。本方法快速、灵敏、重现性好,适用于氟喹诺酮类药物可溶性粉中非法添加利巴韦林的检测。     

HPLC-DAD法检测三种兽用中药注射液中非法添加喹乙醇和乙酰甲喹方法研究

建立HPLC-DAD法测定3种兽用中药注射液中非法添加喹乙醇和乙酰甲喹的方法。以十八烷基键合硅胶为填充剂、乙腈-水(13∶87)为流动相,用二极管阵列检测器进行全波长(200-400 nm)扫描,检测波长为258 nm,并采用峰纯度检查和光谱相似度检查辅助对照品比对方法对非法添加药物进行确证。结果表明,该色谱条件下喹乙醇、乙酰甲喹与其他物质峰分离良好;喹乙醇、乙酰甲喹在0.5-200μg/mL浓度范围内线性良好,回收率为93.2%~109.9%,RSD≤2.8%,喹乙醇、乙酰甲喹的检测限分别为60μg/mL和100μg/mL。本方法简便快捷、准确度和灵敏度高,能满足非法添加物检测的有关法规和要求。     

HPLC-DAD法测定2种中兽药散剂中非法添加非泼罗尼

建立鸡球虫散、驱虫散中非法添加非泼罗尼的液相色谱检查方法。采用Agilent Eclipse Plus-C_(18)(3.5μm,4.6 mm×100 mm)色谱柱,以乙腈-水为流动相,梯度洗脱,二极管阵列检测器,波长采集190～400 nm,检查波长220 nm。通过色谱峰保留时间、峰纯度检查和光谱相似度检查对非泼罗尼进行定性,通过峰面积外标法进行定量。结果表明,方法检测限(LOD)为0.25 g/kg,在0.5 g/kg、2.0 g/kg、5.0 g/kg 3个添加浓度下,平均回收率为95.4%～101.5%,相对标准偏差为1.5%～2.5%,能够满足实际需求。本方法操作简单、检测快速、结果可靠,适用于以上2种制剂中非法添加非泼罗尼的定性定量检测。     

梯度洗脱HPLC法同时测定4种解热镇痛类药物的含量

建立梯度洗脱HPLC法同时测定4种解热镇痛类药物的含量方法。采用十八烷基硅烷键合硅胶色谱柱(4.6 mm×250 mm,5μm),以甲醇-0.05 mol/L醋酸铵溶液为流动相进行梯度洗脱,流速1.0 mL/min,柱温为30℃,检测波长254 nm。结果表明,在该色谱条件下,对乙酰氨基酚、安乃近、安替比林、氨基比林分离良好;对乙酰氨基酚在50～500μg/mL范围内线性良好,R=0.999 8,平均回收率为99.2%(n=9),RSD为0.6%;安乃近在10～250μg/mL范围内线性良好,R=0.999 8,平均回收率为100.6%(n=9),RSD为0.8%;安替比林在10～100μg/mL范围内线性良好,R=0.999 6,平均回收率为99.4%(n=9),RSD为1.0%;氨基比林在10～250μg/mL范围内线性良好,R=0.999 7,平均回收率为98.9%(n=9),RSD为0.8%。本测定方法操作简便,结果准确、可靠,可用于同时测定以上4种解热镇痛类药物的含量。     

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     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -