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。     

Feline intracranial neoplasia: retrospective review of 160 cases (1985-2001)

The purpose of this study was to determine the frequency of different tumor types within a large cohort of cats with intracranial neoplasia and to attempt to correlate signalment, tumor size and location, and survival time for each tumor. Medical records of 160 cats with confirmed intracranial neoplasia evaluated between 1985 and 2001 were reviewed. Parameters evaluated included age, sex, breed, FeLV/FIV status, clinical signs, duration of signs, number of tumors, tumor location(s), imaging results, treatment, survival times, and histopathologic diagnosis. Most of the cats were older (11.3 +/- 3.8 years). Primary tumors accounted for 70.6% of cases. Metastasis and direct extension of secondary tumors accounted for only 5.6 and 3.8% of cases, respectively. Twelve cats (7.5%) had 2 or more discrete tumors of the same type, whereas 16 cats (10.0%) had 2 different types of intracranial tumors. The most common tumor types were meningioma (n = 93, 58.1%), lymphoma (n = 23, 14.4%), pituitary tumors (n = 14, 8.8%), and gliomas (n = 12, 7.5%). The most common neurological signs were altered consciousness (n = 42, 26.2%), circling (n = 36, 22.5%), and seizures (n = 36, 22.5%). Cats without specific neurological signs were common (n = 34, 21.2%). The tumor was considered an incidental finding in 30 (18.8%) cats. In addition to expected relationships (eg, meninges and meningioma, pituitary and pituitary tumors), we found that lesion location was predictive of tumor type with diffuse cerebral or brainstem involvement predictive of lymphoma and third ventricle involvement predictive of meningioma.     

The Prevalence and Intensity of Helminth and Coccidial Infections in Dairy Cattle in Central Kenya

A survey of gastrointestinal parasite infections of young (<6 months old), immature (6–12 months old) and adult (>12 months old) dairy cattle on 16 farms in Kiambu District, Kenya was conducted during a dry season (September 1991 to January 1992) and during a wet season (March to July 1992). The survey was based on monthly coproparasitological examination of cohorts and worm counts in tracer calves. The effects of age, sex, farm and season on the prevalence and intensity of helminth and coccidial infections were determined. Faecal egg and oocyst counts revealed that the overall prevalences were: strongyles (including trichostrongyles) (85.5%), liver flukes (Fasciola gigantica) (34.0%), coccidia (30.9%) and tapeworms (9.6%). Eight species of the protozoan Eimeria were identified, the most prevalent species being E. bovis and E. zuernii. The most prevalent nematode genera were Haemonchus, Cooperia, Oesophagostomum and Trichostrongylus. Season, farm and age of the animals had a significant (p<0.05) influence on the intensity of infection with strongyles, liver flukes and coccidia, whereas the sex of the animals had no significant (p>0.05) effect on the prevalence or intensity of infections. A higher intensity of infection with strongyles and coccidia was found in the wet season than in the dry season (p<0.05). The age-specific intensity was in the following order: for strongyles, immature animals of 6–12 months of age had the highest egg counts, followed by young calves and adults. Calves had significantly (p<0.05) higher oocyst counts than immatures or adults. Liver fluke egg counts did not differ significant (p>0.05) between immatures and adult cattle.     

Hypothalamic dopamine is required for salsolinol‐induced prolactin secretion in goats

The aim of the present study was to clarify the relationship between hypothalamic dopamine (DA) and salsolinol (SAL) for the secretion of prolactin (PRL) in goats. SAL or thyrotropin‐releasing hormone (TRH) was intravenously injected into female goats treated with or without the D₂ DA receptor antagonist haloperidol (Hal), which crosses the blood‐brain barrier, and the PRL‐releasing response to SAL was compared with that to TRH. PRL‐releasing responses to SAL, Hal, and Hal plus SAL were also examined after a pretreatment to augment central DA using carbidopa (Carbi) and L‐dopa. The PRL‐releasing response to Hal alone was greater than that to SAL or TRH alone. The PRL‐releasing response to Hal plus SAL was similar to that of Hal alone. In contrast, the PRL‐releasing response to Hal plus TRH was greater than that to TRH or Hal alone. The treatment with Carbi plus L‐dopa inhibited SAL‐ and Hal‐induced PRL secretion. The inhibition of the PRL‐releasing response to SAL disappeared when SAL was injected with Hal. These results indicate that the mechanisms underlying the SAL‐induced PRL response differ from those of TRH, and suggest that hypothalamic DA and its synthesis is associated in part with SAL‐induced PRL secretion in goats.     

Laboratory diagnosis of respiratory diseases of cattle

The authors describe the procedure of laboratory diagnosis for bovine respiratory diseases: direct diagnosis by isolation and for identification of bacteria or viruses and indirect diagnosis by serological methods. They specify the restraints and limits of this diagnosis and the significance results which are obtained and connected with knowledge of anamnestic information.     

The effect of peri-parturient anthelmintic treatment on the productivity of dairy cattle in subtropical western India

Trials with fenbendazole (Panacur, Hoechst India Ltd) were carried out on two commercial farms in subtropical western India to study the response and economics of nematode treatment in adult dairy cows. Milk yield, lactation length, time to first oestrus and worm egg output were monitored in treated and control groups. Treatment reduced the egg count considerably. Treated cows produced 142 litres more milk over 100 days (p<0.05), with extension of lactation length and advancement of time to first oestrus. The economic gain in terms of milk yield far outweighed the cost of anthelmintic used.     

An Evaluation of the Acceptability as Forage of Some Nutritive and Antinutritive Components and of the Dry Matter Degradation Profiles of Five Species of Ficus

The suitability of five species of Ficus, F. mucoso, F. thonningii, F. polita, F. religiosa and F. benjamina, for feeding ruminant livestock was studied. The nutritive and antinutritive components were determined and the acceptability of the forages to livestock was assessed using a cafeteria method in 8 adult small ruminants. Also, the degradation potential of the dry matter of the five Ficus species was investigated using 3 fistulated sheep. The crude protein (CP) content of the Ficus species varied significantly (p < 0.05), ranging from 130 to 180 g/kg DM. The content of neutral detergent fibre (NDF) also varied significantly (p < 0.05), ranging from 650 to 710 g/kg DM. The organic matter (OM) contents did not differ significantly (p > 0.05), having a mean value of 916 g/kg DM. The concentrations of tannin, saponin, phytic acid and oxalic acid were low. The acceptability of the forage was similar for four of the species but poor for F. polita. The extent of DM degradation varied significant among the Ficus species, the ranking order being F. benjamina > F. thonningii > F. mucoso > F. religiosa > F. polita.     

Macrolides and lincosamides

Macrolides and lincosamides are first choice bacteriostatic antibiotics used in veterinary dermatology. The main antibiotics in these classes are erythromycin, lincomycin, clindamycin and tylosin. They are well absorbed if given orally and are able to penetrate well into infected skin. Their spectrum of action comprises bacteria commonly associated with skin infections, including staphylococci. Their main disadvantages are the rapid development of bacterial resistance and occasional gastroenteric upset, most often seen with erythromycin. More recently developed macrolides, such as azithromycin and clarithomycin, are bactericidal, have a larger spectrum of action, a longer endurance, less resistance and may be given once a day instead of two or three times daily.