国产碘醚柳胺在绵羊体内的药代动力学及组织残留量的研究

给绵羊单剂量口服碘醚柳胺(7.5mg/kg),用HPLC法测定不同时间的血浆药物浓度。结果,碘醚柳胺在血浆中药物代谢动力学符合开放性二室模型,动力学方程为: C_t=208.586 8e~(-0.4756(t-0.5426)) 18.760 5e~(-0.0439(t-0.5426))-227.445e~(-0.5328(t-0.5426))口服碘醚柳胺后,达峰时间(Tmax)为3.698 9±0.197 4d;峰浓度(Cmax)为18.760 5±1.564 6μg/mL;消除半衰期(T(1/2)β)为15.800 6±0.445 7d;曲线下面积(Auc)为459.000 0±62.531 3μg·d/mL。碘醚柳胺在绵羊的肝、肾、胆汁、肌肉中的残留量:停药后28d分别为0.359 9、0.243 2、0.157 9、0.100 0μg/g;停药后50d,肝脏中的残留量为0.100 0μg/g,其它组织中均检测不到;停药后60d,各组织中均无残留。     

国产表阿佛菌素在绵羊体内的药代动力学研究

用反相高效液相色谱结合荧光检测法,对试验绵羊经静脉、皮下单剂量注射0 2 mg/kg表阿佛菌素的药代动力学进行了研究。血样提取物通过C18小柱富集、洗脱,甲醇洗提部分经加入1 甲基咪唑和三氟乙酸酐的乙腈液衍生化后进行色谱分析。血药浓度在 2. 5 ~ 200 ng/mL 范围呈良好线性关系(R= 0 996 8),方法平均回收率96 65%±3.84%,血药最低检测限 2.5 ng/mL,日内、日间变异系数分别小于 10%、12%。2 种途径给药后体内药物运转分别符合二室和一室开放模型。主要药代参数如下,静脉注射:消除半衰期(T1/2β)12.66±2.05 h,药时曲线下面积(AUC0~74)1.02±0 30 (mg/L)·h,fc=0 13±0 05; 皮下注射:吸收半衰期(T1/2ka )4.42±1.04 h,峰浓度(Cmax)0 02±0 01 μg/mL,峰时(Tmax ) 15. 36±2. 91 h,消除半衰期(t1/2k ) 26. 22±9. 04 h,药时曲线下面积(AUC0~122)1.19±0 37 (mg/L)·h。上述结果表明,绵羊静脉注射表阿佛菌素后体内药物分布广泛,消除较慢。皮下注射吸收好,消除比静脉注射更为缓慢,体内药物平均滞留时间长。     

替米考星静脉及皮下注射后在绵羊体内的药代动力学研究

健康成年杂交绵羊静脉和皮下注射替米考星注射液后,用反相高效液相色谱法测定不同时间点血清中的药物浓度。采用3p97药代动力学程序软件处理数据,替米考星两种给药途径的药 时数据均符合二室开放模型静脉注射给药(5 mg/kg bw)的主要药代动力学参数: t1/2a 为 0. 611±0. 017 h、t1/2β为 23. 215±0. 459 h、AUC为11 815±0.396(μg/mL)·h、CL(s)为 0.424±0.014 L/(kg·h)。替米考星皮下注射主要药代动力学参数: 1mg/kg bw剂量组 t1/2a 为 1 751±0 557 h、t1/2β为 22 896±2 747 h、t1/2Ka 为 0. 100±0. 025 h、AUC 为 25. 828±1 479 (μg/mL)·h、CL(s)为0.393±0.017 L/(kg·h),Tmax为0.500±0.065 h,Cmax为1.424±0.156μg/mL、F为109.28%±6.25%。30 mg/kg bw剂量组 t1/2a为1.342±0.244 h、t1/2β为 20.052±1.236 h、t1/2Ka为 0.086±0.015h、AUC为57 575±6.760 (μg/mL)·h、CL(s)为0.527±0.068 L/(kg·h)、Tmax为0.437±0.039 h、Cmax为 3.343±0 512μg/mL、F为81.22%±9.54%。结果表明,绵羊静脉和皮下注射替米考星体内分布广,消除缓慢;皮下注射后在体内吸收迅速,达峰快,生物利用度高。     

阿维菌素长效注射液(油悬剂)与普通注射液在绵羊体内的药代动力学比较研究

本文描述了阿维菌素长效注射液与阿维菌素普通注射液(阿福丁注射液)药物动力学的比较研究。绵羊血浆经提取、纯化、真空干燥和荧光衍生化后,用荧光高效液相色谱法进行检测。用3P87药代动力学分析软件对所测得的结果进行分析,得出以下药代动力学结果;阿维菌素长效注射液和阿福丁注射液在绵羊体内均呈二室代谢模型。长效注射液以1mg/kg体重进行颈部皮下注射得到以下药动学参数;吸收半衰期t_(1 2α)=9.59h,消除半衰期t_(1 2β)=292.97h,达峰时间t_(max)=47.46h,最大血药浓度C_(max)=13.91ng/mL,曲线下面积AUC=6235.48ng/(mL·h),消除率CLB=(0.034L/(kg·h),表观分布容积V_d=13.7L/kg。将阿福丁注射液以0.2mg/kg体重进行颈部皮下注射得到以下药动学参数:吸收半衰期t_(1 2α)=9.05h,消除半衰期t_(1 2β)=144.34h,达峰时间t_(max)=12.63h,最大血药浓度C_(max)=8.52ng/mL,曲线下面积AUC=1017.35ng/(mL·h),消除率CL_B=0.22L/(kg·h),表现分布容积V_d=14.5L/kg。研究结果表明:阿维菌素长效注射液比普通注射液吸收慢、消除慢,在体内维持有效血药浓度的时间长,长效注射液维持有效血药浓度(0.5ng/mL血浆)的时间长于49d,而阿福丁注射液不足21d。     

阿维菌素长效注射液(油悬剂)与普通注射液在绵羊体内的药代动力学比较研究

本文描述了阿维菌素长效注射液与阿维菌素普通注射液(阿福丁注射液)药物动力学的比较研究。绵羊血浆经提取、纯化、真空干燥和荧光衍生化后,用荧光高效液相色谱法进行检测。用3P87药代动力学分析软件对所测得的结果进行分析,得出以下药代动力学结果:阿维菌素长效注射液和阿福丁注射液在绵羊体内均呈二室代谢模型。长效注射液以1mg/kg体重进行颈部皮下注射得到以下药动学参数:吸收半衰期t1/2α=9.59h,消除半衰期t1/2β=292.97h,达峰时间tmax=47.46h,最大血药浓度Cmax=13.91ng/mL,曲线下面积AUC=6235.48ng/(mL·h),消除率ClB=0.034L/(kg·h),表观分布容积Vd=13.7L/kg。将阿福丁注射液以0.2mg/kg体重进行颈部皮下注射得到以下药动学参数:吸收半衰期t1/2α=9.05h,消除半衰期t1/2β=144.34h,达峰时间tmax=12.63h,最大血药浓度Cmax=8.52ng/mL,曲线下面积AUC=1017.35ng/(mL·h),消除率ClB=0.22L/(kg·h),表观分布容积Vd=14.5L/kg。研究结果表明:阿维菌素长效注射液比普通注射液吸收慢、消除慢,在体内维持有效血药浓度的时间长,长效注射液维持有效血药浓度(0.5ng/mL血浆)的时间长于49d,而阿福丁注射液不足21d。     

“棘防E号”在绵羊体内的药代动力学研究

4只绵羊口服“棘防E号”后测定血液中血药浓度变化及药代动力学参数值。结果表明血药浓度—时间曲线符合一室分布模型。药代动力学参数结果为:吸收速度常数(ka)(2.03±0.07)h-1、消除速率常数(ke)(0.36±0.03)h-1、峰时间(Tmax)(5.65±0.77)h、吸收相半增期(T1/2/ka)(3.15±0.18)h、消除相半衰期(T1/2/ke)(4.24±0.17)h、峰浓度(Cmax)(4.98±0.68)mg.L-1、药时曲线下面积(AUC)(27.65±3.54)mg.h-1.L-1、清除率平均值(ALB)(0.53±0.07)mg.kg-1.h-1、体内表观分布容积(Vd)(1.93±0.08)L.kg-1。     

硫酸多粘菌素E在猪体内的药代动力学和生物利用度研究

健康断奶仔猪 5头 ,分别进行单剂量肌注 (2 5和 5 0mg/kgb .w .)和静注 (2 5mg/kgb .w .)给药 ,并用微生物学方法对硫酸多粘菌素E在猪体内的药代动力学和绝对生物利用度进行了研究。以 3P97程序处理血药浓度—时间数据 ,结果表明 ,以 2 5和 5 0mg/kgb .w .的剂量肌注给药时 ,其血清中药物的峰浓度 (Cmax)分别为 3 73± 0 2 8μg/ml和 6 40± 0 1 8μg/ml,达峰时间分别为 32 2 2± 1 51min和 34 1 8± 1 76min ,消除半衰期 (t1 / 2 β)为 2 55 99± 1 3 65min和 2 64 0 8± 2 8 57min ;以 2 5mg/kgb .w .的剂量静注给药时 ,其消除半衰期 (t1 / 2 β)为 2 51 2 8± 1 2 53min。静注和肌注在体内的分布均为一级吸收二室模型。肌注 2 5和 5 0mg/kgb .w .剂量的注射液时 ,其平均绝对生物利用度分别为 98 30 %和 88 54 %。     

氯氰碘柳胺钠对绵羊鼻蝇蚴的驱杀效果观察

应用氯氰碘柳胺钠注射液,按5 mg/kg体重剂量颈部皮下注射,驱除绵羊自然感染的羊鼻蝇蚴,并设空白对照组.结果表明,给药后21 d抽样烟雾熏杀检查及30 d抽样剖检,对绵羊鼻蝇蚴的驱除效果达100%.     

长效环丙沙星注射液注射后不同时间猪血药浓度的测定

按 1 8mg/千克的剂量给 3头健康猪肌肉注射长效环丙沙星注射液 ,用高效液相色谱法测定血浆中药物的质量浓度 ,并用MCPKP药代动力学程序处理所得数据。结果发现该制剂的T1/2 β(消除半衰期 )为 3 0 91h± 0 83 )h ,Cmax(达峰浓度 )为 1 0 9μg/ml± 0 2 7μg/ml,体内消除较慢。肌注后有效血药浓度能维持 60小时     

复方伊维菌素注射液临床效力试验报告

复方伊维菌素注射液(伊维菌素、氯氰碘柳胺钠),经临床试验验证,绵羊按每50 kg体重皮下注射1 mL,可驱杀绵羊胃肠道线虫、吸虫、体外寄生虫(蝇蛆),总有效率高达93%以上.结果表明,2种驱虫药物配比合理,具有明显的相互增效、提高杀虫谱的作用.     

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.     

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

Tropical Animal Health and Production -     

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.     

Chemotaxis of macrophage in inflammation

Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.     

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