喹烯酮在猪、鸡体内的药代动力学研究

猪6头,鸡10只,单剂量0 4065mg·kg-1(比活度24 6μci mg-1)静注给药,一个月后,单剂量31 15mg·kg-1(比活度5 187μci·mg-1)口服给药,进行代谢动力学研究。依据本实验建立的方法,以液体闪烁谱仪计数法进行含量测定。喹烯酮以原药的形式代谢排泄,静注给药符合二室开放模型:猪,T1/2α=0 1899h,T1/2β=4 5528h,Kel=0 8654h-1,AUC=0 00925mg·h-1·L-1;鸡,T1/2α=0 1637h,T1/2β=3 8189h,Kel=1 6834h-1,AUC=0 005046mg·h-1·L-1。口服给药符合一级吸收一室开放模型:猪,T1/2Ka=0 4678h,T1/2β=3 7445h,Tp=1 3367h,Cmax=0 000713μg·ml-1,AUC=0 00303mg·L-1·h-1;鸡,T1/2Ka=0 5142h,T1/2β=4 6637h,Tp=1 8459h,Cmax=0 000897μg·m-1,AUC=0 00773mg·L-1·h-1,说明喹烯酮口服给药后,其吸收较快,消除相对也较快,生物利用度低。     

口服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 5头健康猪口服和静脉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 99.0 3%,血清最低检测浓度为 0 .0 5 μg/ ml,日内日间变异系数为 2 .2 %～ 5 .0 %,且血清浓度在0 .0 5～ 3μg/ m l范围呈良好线性关系 (r=0 .996 5 )。以 2 0 mg/ kg口服和以 2 0 mg/ kg静脉注射硫酸安普霉素后 ,经 Mcpkp药代动力学计算机程序处理 ,体内药物运转分别符合开放型一室和二室模型 ,生物半衰期 t1 / 2 分别为 (7.36± 1 .5 2 ) h和 (3.1 7± 0 .75 )h;CLB分别为 4 .82 L / kg· h和 0 .1 6 L / kg· h;AUC值分别为 4 .1 4和 1 30 .6 2。口服 :Cmax为 (0 .2 4± 0 .0 3)μg/ ml;Tp为 (5 .1 2±0 .6 1 ) h;T1 / 2 K为 (7.36± 1 .5 2 ) ;生物利用度 (AUCp.0 / AUCi.v)为 (3.1 92 8± 0 .70 4 4 ) %。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     

盐酸克林霉素(clindamycin)在健康猪及链球菌感染猪体内的药代动力学

盐酸克林霉素按每公斤体重 11mg单一剂量肌肉注射 ,分别观察了其在健康猪 (n=5 )和链球菌感染猪 (n =5 )体内的药代动力学。用高效液相色谱法测定盐酸克林霉素的血药浓度 ,所得血药浓度 -时间数据采用 MCPKP软件进行分析。在健康猪体内的药代动力学参数如下 :Cmax为 (2 .5 46 43± 0 .2 2 42 ) mg/ L,T1 /2 为 (3.2 10± 0 .795 3) h,AUC为(17.86 5 72± 1.2 5 46 ) m g· h/ L ,Tmax为 (2 .18796± 0 .44 37) h。在链球菌感染猪体内的药代动力学参数如下 :Cmax为(2 .5 5 6 89± 0 .12 45 ) mg/ L ,T1 /2 为 (2 .6 912 3± 0 .8895 2 ) h,AUC为 (12 .0 0 6 5 4± 3.2 5 46 ) mg· h/ L ,Tmax为(1.16 176± 0 .5 436 ) h。     

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。     

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%.     

碱性诺氟沙星在健康猪体内的药动学

按 10 mg/kg单一剂量对健康猪分别肌注和静注碱性诺氟沙星注射液后 ,研究了其在猪体内的药代动力学。应用 HPL C法测定猪体内的血药浓度 ,所得数据应用 MCPKP药动学软件处理 ,结果为 :肌注碱性诺氟沙星 ,Cmax(2 .6 30 80± 0 .6 830 6 ) mg/L,T1 /2 (6 .0 75 17± 3.0 4 76 1) h,AUC(12 .4 99± 2 .4 2 3) mg/L· h,F4 8.4 % ;静注碱性诺氟沙星 ,Co(12 .736 4 8± 5 .1835 2 ) mg/L,T1 /2 (3.312 89± 0 .4 84 39) h,AUC(2 5 .74 7± 3.14 9) mg/L·h。     

盐酸诺氟沙星在家蚕体内的药物动力学研究

为了给家蚕细菌病的预防和治疗提供合理用药的理论依据 ,采用微生物测定法研究了盐酸诺氟沙星在健康家蚕体内的药物动力学特征 ,以MCPKP药代动力学程序处理药时数据。结果表明 :盐酸诺氟沙星在蚕体内的药时数据符合一级吸收一室开放式模型 ,主要药物动力学参数 :T1/2Ka=1 797± 0 0 2 3h ,T1/2Kel=1 778± 0 0 12h ,Tmax=3 4 2 8± 0 0 0 8h ,Cmax=14 80 8± 0 6 4 5 μg/mL。     

喹烯酮及其主要代谢物在猪体内的药动学研究

本试验旨在研究喹烯酮及其主要代谢物在猪体内的药物代谢动力学过程。将喹烯酮按40 mg/kg的剂量对7头猪进行灌胃给药,采用HPLC-MS/MS法测定血浆中喹烯酮及其主要代谢物的浓度,药代动力学软件WinNonlin 5.2处理血浆中药物浓度－时间数据。灌胃给药后猪血浆中能检测到原药和N1-脱氧喹烯酮、脱二氧喹烯酮及3-甲基喹噁啉-2-羧酸(MQCA)3种代谢物。喹烯酮的浓度－时间数据符合一级吸收一室开放模型,其主要药代动力学参数为:T_1/2Ka＝(0.97±0.08)h,T_1/2λz＝(2.79±0.16)h,CL＝(26.03±0.65)L/h·kg,Cmax＝(0.26±0.01)μg/mL,Tmax＝(2.23±0.06)h,AUC＝(1.54±0.04)h·μg/mL;采用统计矩法处理N1-脱氧喹烯酮和脱二氧喹烯酮的浓度－时间数据,N1-脱氧喹烯酮主要药代动力学参数为:Tmax＝(6.33±1.37)h,Cmax＝(8.81±2.08) ng/mL,T_1/2λz＝(3.03±1.27)h,AUC＝(0.07±0.01)h·ng/mL,MRT＝(6.58±0.40)h;脱二氧喹烯酮的主要药动学参数:Tmax＝(10.29±0.29)h,Cmax＝(6.20±1.11)ng/mL,T_1/2λz＝(5.84±2.78)h,AUC＝(0.15±0.01)h·ng/mL,MRT＝(3.64±0.72)h。同时,在少数时间点检测到代谢物MQCA。猪口服喹烯酮后,吸收较快,消除较慢。血浆中检测到N1-脱氧喹烯酮、脱二氧喹烯酮及3-甲基喹噁啉-2-羧酸3种代谢物,且浓度较低、消除缓慢。     

喹烯酮在猪组织中的残留研究

目的 :建立起定量测定猪肝脏、肾脏、肌肉、脂肪食用组织中喹烯酮的高效液相色谱检测方法 ,依据测定的结果制定最高残留限量 ,定出其休药期。方法 :猪 45头 ,公母各半 ,按正常饲料添加喹烯酮 50 mg/ kg饲喂 2 .5月后 ,分别于4h、1 d、2 d、3 d、4d、6d、8d、1 2 d、1 5d采样。检测采用 Prodigy5μ Phenyl-3色谱分析柱 (4.6mm× 2 50 mm5μm icron) ,Waters TM486可变波长紫外检测器 ,甲醇 -水 (70∶ 3 0 )为流动相。组织样品用乙酸乙酯、乙腈、正已烷、氯仿等试剂提取处理纯化后进样 ,在 3 1 2 nm波长处检测 ,流速为 1 .0 m L·min- 1。结果 :标准曲线的线性范围为 :脂肪、肝脏 ,0 .0 0 5～ 0 .80 0μg· g- 1;肾脏、肌肉 ,0 .0 0 8～ 0 .0 80μg· g- 1。它们的复相关系数均大于 0 .99。精密度考察喹烯酮的日内各组织各浓度的 RSD(相对标准差 )均小于1 2 % ,日间测得各组织各浓度的 RSD均小于1 8.5%。喹烯酮在肌肉、脂肪、肾脏中均无残留 ,而在肝脏中的残留量也很小 ,4d以后再无残留。结论 :本试验测定方法灵敏度高 ,重复性好。停药后 4h所有可食用猪组织中喹烯酮浓度均低于计算所得的安全组织浓度 ,故该药在猪使用上无休药期 ,即休药期为零天。     

单剂量静注绿原酸在奶山羊体内的药代动力学研究

以9 mg/kg的剂量给奶山羊静注绿原酸后,采用高效液相色谱法测定药动学参数。流动相为甲醇∶1%冰醋酸(20∶80),色谱柱为Agilent Eclipse XDB-C18(5μm×4.6 mm×150mm),紫外检测波长327 nm,柱温25℃,流速1 mL/min。绿原酸在奶山羊体内呈二室开放模型,其药代动力学参数CO/(μg.mL-1)=20.978 8±6.322 2,A/(μg.mL-1)=17.364 0±5.594 3,B/(μg.mL-1)=3.614 7±1.637 7,α/h-1=22.293 2±5.003 8,β/h-1=5.969 2±0.907 9,t1/2β/h=0.118 6±0.020 5,AUC/(mg.L-1.h-1)=1.366 8±0.251 5。     

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 -