国产克洛素隆在绵羊体内的药代动力学和生物利用度研究

应用 YWG-C1 8色谱柱 ( 2 5 0 mm× 4.6mm,5 μm) ,Waters TM486型可调波长紫外检测器 ,检测波长 2 65 nm;0 .0 1 M磷酸钾 ( p H=7.0 )∶乙腈 ( 3∶ 1 )为流动相 ;含量测定采用标准曲线法 ,建立了反相 HPLC法检测绵羊血浆中克洛素隆含量的方法。同时对绵羊以 7mg/ kg单剂量经静脉注射、口服 2种途径给药的药代动力学及生物利用度进行了研究。血药浓度在 0 .0 0 5～ 2 .0 μg/ ml及 2 .0～ 5 0 .0 μg/ ml范围呈良好线形关系 ( R=0 .9941、0 .9970 ) ,平均回收率 93 .2 %,血药最低检测限 0 .0 0 5 μg/ ml,日内日间变异系数分别小于 1 0 %、1 1 %。2种途径给药后血药浓度结果经 MCPKP药代动力学统计软件处理 ,体内药物运转分别符合三室开放模型和一室开放模型。结果表明 ,绵羊静注克洛素隆后体内药物分布广泛 ,口服后吸收较好 ,但消除较静注缓慢。     

国产克洛素隆尿药排泄数据分析

应用Kromasil-C18色谱柱(250 mm×4.6 mm,5 μm),WatersTM480型可调波长紫外检测器,0.01M磷酸钾(pH=7):乙腈(3:1)为流动相,检测波长265 nm,含量测定采用标准曲线法,建立了RP-HPLC法检测绵羊尿中克洛素隆含量的方法.方法有效性评价结果表明,尿药含量在0.01～5.0μg/ml及5.0～30.0μg/ml范围呈良好线形关系(r=0.9993、0.9995),方法平均回收率99.32%,日内、日间变异系数分别为3.91%、6.28%.尿药最低检测限0.005μg/ml.试验绵羊以7 mg/kg单剂量经静脉、肌肉及口服三种途径给药后,尿中药物浓度分析表明,克洛素隆经体内处理后主要经肾脏排泄,给药96 h内,静注经尿排泄原药为81.76%,肌注为64.03%,口服为48.50%.     

克洛素隆注射剂在绵羊体内的药物动力学研究

研究了克洛素隆注射剂在绵羊体内的药物动力学过程。以邻甲苯磺酰胺为内标,建立应用RP-HPLC检测绵羊血浆中克洛素隆含量的方法,血浆浓度在0.01μg/mL~1.0μg/mL及1.0μg/mL~20.0μg/mL范围呈良好线性关系,方法回收率和精密度均能满足药物动力学分析的要求。结果表明,绵羊按4mg/kg单剂量皮下注射克洛素隆,体内药物运转符合二室开放模型。主要药物动力学参数分别为:t1/2Ka=1.355h±0.746h,t1/2β=17.924h±9.186h,tmax=3.181h±1.046h,Cmax=5.121μg/mL±0.997μg/mL,AUC=56.730(mg/L)·h±5.248(mg/L)·h。克洛素隆注射剂皮下注射吸收快,消除较慢,适于绵羊临床寄生虫病的防治。     

硫酸安普霉素在猪体内的药代动力学研究

实验猪6头,单剂量(20mg/kg)静脉注射国产硫酸安普霉素,用微生物法测定血清药物浓度,研究其在猪体内的药代动力学.结果平均回收率为99.03%,血清最低检测浓度为0.05μg/ml,日内日间变异系数为2.2%～5.1%,且血清浓度在0.05～3.00μg/ml范围呈良好线性关系(r=0.9965).猪静脉注射硫酸安普霉素血药浓度,经Mcpkp药代动力学计算机程序处理,体内药物运转符合开放型二室模型,t1/2c(0.75士0.21)h,t12β(3.019±0.67)h,CLB为(0.16士0.01)1/kg·h     

兽用复方涂膜剂中蛇床子素在兔体内的药代动力学

研究复方蛇床子涂膜剂中蛇床子素在兔体内的药物代谢动力学。试验兔经透皮给药后,用高效液相色谱法以甲醇-水(80∶20)作为流动相,测定血液中蛇床子素的含量,采用3P87程序计算药物代谢动力参数。结果显示,蛇床子素经透皮给药后药代动力学符合二房室开放模型,T1/2α=3.291 h,T1/2β=25.378 h,K21=0.138 h-1,AUC=5.342μg·mL-1×h,Tmax=3.683 h,Cmax=0.162μg·mL-1。研究表明:复方蛇床子涂膜剂中蛇床子素能够透过皮肤进入血液,并维持一定的血药浓度。     

猪血浆中六茜素的HPLC测定及药代动力学

采用YWG-C18色谱分析柱(4.6 mm×250 mm,5 μm),Waters TM486可变波长紫外检测器,甲醇-水(4060)为流动相,香草醛为内标;血液样品用乙醚提取纯化后进样,220 nm波长处检测,建立了反相HPLC法检测猪血浆中六茜素(pyroline,PL)含量的方法,同时对PL静脉单次给药(30 mg/kg)后在猪体内的药代动力学进行了分析.结果表明,PL在血液中的线性范围为1.0～100.0 mg/L(r=0.995 3),最低检测量0.1 μg,最低检出质量浓度2.0 mg/L,平均方法回收率为98.36%,精密度考察PL日内、日间相对标准偏差小于4%.所得的PL血药时程符合二室开放模型,药物动力学参数为T1/2a=1.52 min,T1/2β=66.05 min,AUC=880.07 mg/(min@L).表明PL单次给药后,在体内分布广泛而迅速,消除快.试验所建立的HPLC检测法专属性高,快速、准确、重复性好.     

长效土霉素注射液在猪体内的药代动力学研究

建立了土霉素在猪血浆中含量测定的高效液相色谱法，研究了其在猪体内的药代动力学。土霉素检测的线性范围为0．25～32．0lμg／mL，相关系数为0．9997，最低定量限为0．25μg／mL。药代动力学研究表明，给猪单剂量肌肉注射土霉素25mg／kg体重后，其血药浓度一时间曲线符合一级吸收二室模型，参数为Tmax=2h,Cmax=7．62lμg／mL,t1/2β=69．315h，V1／F=4．648L／kg，说明长效土霉素在体内逐渐吸收和广泛分布后，在组织中能长时间地维持较高的血药浓度，能达到长效之目的。本试验能对兽药药代动力学研究和制定长效土霉素注射液合理给药方案提供参考。     

肌肉注射硫酸安普霉素在猪体内的药代动力学和生物利用度研究

对6头健康猪单剂量静脉注射、肌肉注射国产硫酸安普霉素,研究其在猪体内的药代动力学和生物利用度.用微生物法测定血清药物浓度,结果平均回收率为99.03%,血清最低检测浓度为0.05μg/ml,日内日间变异系数为2.2%～5.1%,且血清浓度在0.05～3μg/ml范围呈良好线性关系(r＝0.9965).对猪静注、肌注硫酸安普霉素20mg/kg后,经MCPKP药代动力学计算机程序处理,体内药物运转符合开放型二室模型,肌肉注射0.856h后达峰药浓度Cmax为36.09±1.22μg/ml;t1/2分别为1.58±0.67h、1.06±0.11h,CLB分别为0.15L/kg/h、0.17 L/kg/h,V1分别为0.71L/kg、0.1L/kg,绝对生物利用度为AUC i.m/AUC i.v＝88.47%±3.32%,上述药代动力学数据为动物临床用药提供有价值的理论依据.     

头孢噻呋钠在猪体内的药代动力学和生物利用度研究

用微生物杯蝶法测定血清药物浓度,6头实验猪按5 mg/kg单剂量静注、肌注头孢噻呋钠(Ceftiofur Sodium),对其药代动力学和生物利用度进行了研究.试验菌为蜡样芽孢杆菌1.1687,结果平均回收率为96.52%,血清最低检测浓度为0.15 μg/ml,日内日间变异系数为2.5%～4.9%,血清浓度在0.3～0.8 μg/ml范围内呈良好线性关系(r=0.9884).药时数据经Mcpkp药代动力学计算机程序处理,猪静注、肌注头孢噻呋钠体内药物运转都符合二室开放模型,其中静注的药代动力学参数为T1/2α=2.22 h,T1/2β=14.64 h, K12=0.09/h, K21=0.078/h, Kel=0.20/h, V1=0.34 l/kg, VB =1.38 l/kg, CLB=0.07 l/kg/h,AUC=76.56 mg/l*h; 肌注药代动力学参数为Tmax=0.69 h,Cmax=12.09 μg/ml,T1/2ka=0.19 h,T1/2β=15.18 h,Kel=0.23/h,K12=0.14/h,K21=0.08/h;生物利用度为AUCi.m/AUCi.v=87.97%.     

纳米维生素D_3药物代谢动力学的研究

根据纳米维生素D_3在本试验条件下血药浓度测定结果,运用DAS2.0软件测算其药代动力学参数。结果显示纳米维生素D_3的达峰时间T_(max)=8h,峰浓度C_(max)=5.77μg/ml,半衰期T_(1/2)=24h,药时曲线与横坐标包围所形成的面积AUC_(0-100)=452.7μg/ml。计算出纳米维生素D_3与普通维生素D_3的相对生物学效价为222.1%,表明纳米维生素D_3在动物体内吸收速度更快、最大血药浓度值大、生物学效价更高。     

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     

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

Tropical Animal Health and Production -