单剂量氟苯尼考内服及肌注在家兔体内药代动力学研究

健康新西兰白兔20只,随机分为A、B 2组,A组内服单剂量30 mg/kg氟苯尼考试验品,B组肌注单荆量30mg/kg氟苯尼考试验品.用高效液相色谱法测定血浆中的药物浓度,3p97药代动力学程序软件处理药--时数据,A组药--时数据符合--室开放模型(W=1/C2),主要药代动力学参数T1/2Ka=(0.461±0.066)h,T1/2ke=(2.013±0.195)h,Tpeak=(1.180±0.123)h,Cmax=(7.332±1.000)mg/L,AUC=(31.445±3.566)mg·L-1·h,V/F=(2.995±0.330)L/kg;B组药-时数据也符合一室开放模型(W=1/C2),主要药代动力学参数T1/2Ka=(0.802±0.098)h,T1/2ke=(2.317±0.136)h,Tpeak=(1.805±0.103)h,Cmax=(6.646±0.578)mg/L,AUC=(38.714±3.727)mg·L-1·h,V/F=(2.772±0.303)L/kg.试验结果表明,氟苯尼考在家兔体内主要药动学特征为内服吸收迅速、分布快而广、消除较快;肌注吸收速度显著慢于内服.分布广泛,消除也较快.     

替米考星水溶性粉在家兔体内的药动学研究

为了考察替米考星水溶性粉在家兔体内的药动学特征,本试验分别给受试家兔灌服替米考星、替米考星肠溶微丸、替米考星水溶性粉,以12.5 mg/kg体重剂量给药,采用HPLC方法分析不同时间点受试家兔血浆中替米考星的药物浓度。试验结果显示,新研制的20%替米考星水溶性粉经口服后,药物在家兔体内可被快速吸收达到较高的血药浓度0.413±0.148μg/m L,血药浓度-时间曲线下的面积(AUC)为4.334±0.620μg/m L·h,相对生物利用度(F)达到86.99%,说明替米考星水溶性粉经口服后的生物利用度较高,有利于致病菌细菌的抑制或杀灭。     

两种替米考星可溶性粉在鸡体中的药动学比较研究

将24只健康肉用商品鸡(公母各半)随机分为A、B两组,分别单剂量灌服10%替米考星可溶性粉和10%磷酸替米考星可溶性粉,给药量均为12 mg/kg体重,进行药动学比较研究。给药后按预定时间采集血样,采用高效液相色谱法(HPLC)法测定血浆中药物含量。实测血药浓度-时间数据,采用Win Nonlin5.2.1药动学分析软件处理。结果显示,A组平均消除半衰期(T1/2β)约为33.786 h,达峰时间(Tmax)和峰值浓度(Cmax)分别为1.125 h和0.377μg/m L,平均曲线下面积(AUC)为2.322μg/m L·h,平均滞留时间(MRT)为9.345 h;B组T1/2β约为37.272 h,Tmax和Cmax分别为1.167 h和0.358μg/m L,AUC为2.444μg/m L·h,MRT为9.698 h,相对生物利用度约为105.3%。结果表明,两种替米考星饮水剂上述药动学参数无明显差异(P0.05)。     

犬口服国产麻保沙星溶液的生物利用度研究

本研究旨在考察国产麻保沙星溶液在健康犬体内的药动学特征及生物利用度.选用8只健康犬,按照随机拉丁方设计,进行单次不同单剂量(2.75 mg·kg-1)分别静注麻保沙星溶液和口服麻保沙星溶液制剂.血浆样品经乙腈沉淀血浆蛋白,高速离心,用反相高效液相色谱法测定犬血浆中麻保沙星的浓度,3P97药动学计算软件处理血浆药物浓度-时间数据.健康犬静注给药的药物动力学最佳数学模型为无吸收开放二室模型,主要药动学参数为:T1/2α(0.34±0.14)h,T1/2β(7.74±1.70)h,V(1.03±0.60)L·kg-1,CL(0.22±0.08)L·h-1;AUC(14.05±4.25)mg·mL-1·h.口服给药的药物动力学最佳数学模型为一级吸收二室模型.主要药动学参数为:T1/2α((2.82±1.86)h,T1/2β(16.03±9.27)h,V/F(2.25±0.34)L·kg-1,CL/F(0.21±0.05)L·h-1,Tmax(1.55±0.62)h,Cmax(0.89±0.21)μg·mL-1,AUC(13.66±2.77)mg·mL-1·h.肌注麻保沙星冻干粉针的生物利用度为97.22%.麻保沙星在健康犬体内口服的主要药动学特征为吸收较快,达峰时间短,半衰期较长,生物利用度高.     

环丙沙星和磺胺间甲氧嘧啶联合用药在猪体内的血浆药动学

采用高剂量CIP(20mg/kg体质量)和SMM(100mg/kg体质量)联合肌注给药,同步检测试验猪各采血点的血药浓度,通过DAS药物动力学程序软件分析血药浓度—时间数据。结果显示:CIP和SMM在联用时药时数据均符合一级吸收二室开放模型,CIP主要的药动学参数:t1/2为(4.98±0.60)h,Vd为(6.61±0.81)L/kg,AUC为(21.79±1.01)(mg/L)·h,Cmax为(7.56±0.26)mg/L,t1/2Ka为(0.93±1.86)h;SMM主要的药动学参数:t1/2为(4.98±0.92)h,Vd为(1.06±0.19)L/kg,AUC为(679.99±13.17)(mg/L)·h,Cmax为(72.75±3.26)mg/L,t1/2Ka为(0.72±0.36)h。联合用药符合生产中多种药共用的情况,为以后多类属药物残留消除规律研究提供参考。     

三聚氰胺在鸡体内的药动学研究

40日龄岭南三黄肉鸡30只,随机分为2组,分别进行了静注和口服三聚氰胺(20 mg/kg)的药动学研究。用反相高效液相色谱法测定鸡血浆中三聚氰胺的浓度,WinNonlin计算机程序软件处理静注和口服的血浆药物浓度-时间数据。健康鸡静注给药的药时数据适合二室开放模型,主要药物动力学参数为:t1/2α(1.95±0.34)h;t1/2β(9.71±4.28)h;Vc(1.54±0.11)L/kg;Vd(area)(4.10±0.33)L/kg;ClB(0.42±0.08)L.kg-1.h;AUC(49.28±9.97)mg.L-1.h。健康鸡内服三聚氰胺的药时数据适合一级吸收二室开放模型,主要药动学参数为:t1/2α(1.98±0.24)h;t1/2β(12.05±5.66)h;tmax(2.05±0.74)h;Cm ax(5.87±0.94)mg/L;AUC(40.76±6.33)mg.L-1.h。三聚氰胺在健康鸡体内的主要药动学特征为,口服吸收较完全,分布广泛,消除缓慢。     

麻保沙星(marbofloxacin)在猪体内的药物动力学

选用 18头健康的杜洛克×大白×长白三元杂交断奶仔猪 (公母兼有 ,体质量在 2 0～ 2 3kg)杂交猪 ,随机分为 3组 ,每组 6头 ,按每千克体质量 2 .5 mg的剂量进行了静注、肌注及内服麻保沙星 (m arbofloxacin)的药动学研究。三氯甲烷萃取血浆中的药物 ,用反相高效液相色谱法测定血浆中药物的浓度 ,MCPKP药代动力学程序处理血药浓度 -时间数据。静注给药的药时数据符合三室开放模型 ,主要药动学参数为 :t1 /2π(0 .13± 0 .0 1) h;t1 /2α(5 .4 1± 0 .4 3) h;t1 /2β(16 .2 2± 1.6 0 ) h;AUC(2 4 .89± 1.5 1) mg· L- 1· h;V1 (0 .77± 0 .0 6 ) L· kg- 1 ;Vd( area) (2 .6 1± 0 .37) L· kg- 1 ;Vd( ss)(1.6 9± 0 .19) L· kg- 1 ;Cl B(0 .10± 0 .0 1) L· kg- 1·h。肌注给药的血浆药时数据符合一级吸收二室开放模型 ,主要药动学参数为 :t1 /2 Ka(0 .2 7± 0 .16 ) h;t1 /2α(2 .87± 0 .90 ) h;t1 /2β(17.39± 1.6 2 ) h;tmax(0 .91± 0 .32 ) h;Cmax(1.96± 0 .2 4 ) mg· L- 1 ;AU C(2 6 .85± 3.5 1) mg· L- 1 · h;F(10 7.86± 14 .10 ) %。内服给药的血浆药时数据符合一级吸收二室开放模型 ,主要药动学参数为 :t1 /2 Ka(1.16± 0 .19) h;t1 /2α(4.94± 0 .5 3) h;t1 /2β(2 2 .98± 2 .0     

复方替米考星可溶性粉在鸡体内的药动学研究

本研究比较了口服复方替米考星可溶性粉与单独肌注替米考星注射液和静注磺胺二甲嘧啶钠注射液在鸡体内药物代谢动力学特征和相对生物利用度。36只健康鸡,随机分为3组,给药剂量均为20 mg/kg,翼下静脉采血,高效液相色谱法检测鸡血浆中的药物浓度。采用药动学软件Win Nonlin 6.1的非房室模型分析方法,计算出药物的动力学参数。鸡口服复方替米考星可溶性粉、肌注替米考星注射液和静注磺胺二甲嘧啶钠注射液后的药时曲线下面积(AUC)分别为:9.49±3.64、37.17±10.82、12.40±4.11、61.31±11.38μg×h/m L。复方替米考星可溶性中替米考星相对于肌肉注射的替米考星的生物利用度为75.98%,复方制剂中磺胺二甲嘧啶钠的绝对生物利用度为60.63%。复方替米考星可溶性粉和单方药物相比,药动学参数经t检验,t_(1/2)、T_(max)、C_(max)、AUC、MRT等存在显著性差异(P0.05)。结果表明复方替米考星可溶性粉单剂量口服给药吸收较慢,达峰时间显著延迟,平均驻留时间显著延长,有利于抗菌作用的发挥。     

桔梗的“引经”作用对氟苯尼考药动学的影响

20只新西兰白兔随机均分成2组(A、B组),A组单剂量1次灌胃内服氟苯尼考30 mg/kg;B组氟苯尼考30mg/kg与桔梗煎液2 g/kg单荆量1次同时灌胃内服给药;采用高效液相色谱法测定血药浓度,血药浓度最低检测限为0.05 mg/L,以3p97药代动力学程序和SPSSl2.0统计分析软件对所得数据进行分析.结果,药-时数据均符合一级吸收一室开放模型(W=1/C2),主要药代动力学参数及拟合方程如下.A组:T1/2ka(0.461±0.066)h,T1/2kc(2.013±0.195)h,Tpeak(1.180±0.123)h,Cmax(7.332±1.000)mg/L,AUC(31.445±3.566)mg·h-1·L-1,V/F(2.995±0.330)L/kg,拟合方程为:C=19.833(e-0.396t-e-2.387t);B组;T1/2ka(0.550±0.112)h,T1/2ke(3.308±0.270)h,Tpeak(1.414±0.183)h,Cmax(4.737±0.360)mg·L-1,AUC(23.128±2.096)mg·h-1·L-1,V/F(1.400±0.127)L/kg,拟合方程为:C-11.021(e-0.342t-e-10860t).结果表明,桔梗与氟苯尼考同时灌胃内服后,桔梗的"引经"对氟苯尼考在家兔体内药物代谢有较大影响.     

20%吡喹酮注射剂在水牛体内的药代动力学研究

4头成年健康水牛采用随机交叉实验设计,分别进行吡喹酮注射剂肌注和吡喹酮片内服给药的药动学试验.吡喹酮注射剂按10 mg/kg的剂量单次肌注,吡喹酮片按20 mg/kg的剂量单次内服给药.采用高效液相色谱法测定血浆中吡喹酮的质量浓度,方法最低检测限和定量限分别为0.01 mg/L和0.062 5 mg/L.吡喹酮注射剂单剂量肌注给药,血药浓度-时间数据符合一级吸收一室开放模型,其主要动力学参数分别为:t1/2(ka)(0.45±0.029)h,t1/2(ke)(5.04±0.1 0)h,T(peak)(1.72±0.029)h,C(max)(0.87±0.006)mg/L,V(c)(8.58±0.010)L/kg,AUC(7.99±0.005)mg·L-1·h-1.吡喹酮片单剂量口服给药血药浓度-时间数据符合有吸收-室开放模型,其主要动力学参数分别为:Lagtime(0.13±0.010)h,t1/2(ka)(0.76±0.11)h,t1/2(ke),(1.31±0.076)h,T(peak)(3.84±0.026)h,C(max)(0.51±0.006)mg/L,V(c)(26.07±1.221)L/kg,AUC(7.99±0.005)mg·L-11·h-1.肌注相对生物利用度为(232±12.9)%.研究结果表明,20%吡喹酮注射剂肌注给药吸收迅速且完全,具有较高的生物利用度;吡喹酮吸收后在体内广泛分布.     

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