乳酸恩诺沙星可溶性粉在鸡体内的药动学研究

24只苏禽黄羽肉鸡随机分成2组,分别按10 mg/kg体重剂量静注和内服乳酸恩诺沙星。测定乳酸恩诺沙星在鸡体内的药动学参数和生物利用度。恩诺沙星血药浓度数据用3p87计算机软件处理。静注乳酸恩诺沙星后的血药浓度-时间数据符合二室开放模型,主要动力学参数:t1/2α(0.45±0.16)h,t1/2β(7.02±1.42)h,CL(s)(0.38±0.10)L/kg/h,AUC(23.69±5.56)(mg/L)×h。内服乳酸恩诺沙星的血药浓度时间数据,符合有吸收因素二室模型,主要动力学参数:t1/2ka(0.60±0.01)h,t1/2ke(8.25±1.73)h,tpeak(2.44±0.17)h,Cmax(1.44±0.30)mg/L,AUC(20.74±3.80)(mg/L)×h,F 87.54%。结果表明,乳酸恩诺沙星可溶性粉在鸡体内具有吸收快、分布广、消除较慢以及内服生物利用度高的药动学特征。     

喹乙醇在鸡体内的药物动力学及组织浓度研究

本文对24只健康石岐杂中鸡单剂量内服(30mg/kg)和静注(20mg/kg)喹乙醇作了药动学分析,对32只健康石岐杂中鸡单剂量内服喹乙醇(30mg/kg)作了组织浓度测定。用高效液相色谱法测定不同时间血浆和组织的药物浓度。喹乙醇静注给药后的血药浓度——时间数据用房室分析法、内服给药后的血药浓度——时间数据用统计矩理论非房室分析法处理。经计算所得的主要动力学参数如下,内服:t1/2 ka 0.64±0.10h,t1/2 ke 1.25±0.06h,AUC_(po) 68.84±3.12mg/L·h;静注:t1/2α 0.27±0.02h,t1/2β 1.72±0.03h,Vd 0.56±0.05L/kg,CL_B 0.23±0.01L/kg/h,AUC_(iv) 87.20±1.58mg/L·h。生物利用度F为52.99±2.32％。组织浓度测定结果表明,喹乙醇在肌肉、肝、肾、脾、肺的浓度较低,给药后24小时,这五种组织中喹乙醇的残留已低于检测限(0.2μg/g)。喹乙醇在鸡体内的吸收、分布、消除均迅速。     

磺胺嘧啶在成年绵羊血中浓度的监测

对5只成年绵羊,按40mg/kg体重静脉注射磺胺嘧啶,给药手5、15、30分钟和1、2、3、10小时分别测定血药浓度,结果5分钟时血药浓度为12.98±0.75mg％,1小时血药浓度降至6.71±0.34mg％。下降迅速。2个小时后,血药浓度下降的缓慢,1～2小时,血药浓度由6.71±0.34mg％下降至4.71±0.99mg％。可见磺胺嘧啶给绵羊静注后1～2小时,其血药浓度即降至最低抑菌浓度。给药后10小时血药浓度下降至1.40±0.90mg％,明显低于最低抑菌浓度。     

特比萘芬在比格犬体内的药动学和绝对生物利用度

8只健康比格犬采用随机交叉试验设计,盐酸特比萘芬注射液按5 mg/kg单剂量静注,盐酸特比萘芬片按20mg/kg单剂量口服给药,洗脱期为2周。采用高效液相色谱法测定犬血浆中特比萘芬的浓度,以药动学分析软件WinNonlin5.2的非房室模型分析方法处理血药浓度-时间数据。结果显示,犬静注盐酸特比萘芬注射液的药动学参数分别为:Tmax(0.083±0.000)h,Cmax(3.334±0.185)mg/L,T1/2β(15.158±8.558)h,MRT(2.443±1.132)h,AUClast(1.803±0.374)h·mg/L,Vd(49 778.164±25 594.370)mL/kg,CLB(2 414.907±577.369)kg·mL/h。犬口服盐酸特比萘芬片的主要药动学参数为:Tmax(1.875±0.791)h,Cmax(0.324±0.126)mg/L,T1/2β(18.150±10.557)h,MRT(5.019±1.591)h,AUClast(1.094±0.588)h·mg/L,Vd(395 321.202±236 694.989)mL/kg,CLB(14 340.535±3 560.508)kg·mL/h,Flast(16.589±11.495)%,F0~∞(18.236±8.114)%。结果表明,特比萘芬片剂在犬体内吸收迅速,保留时间更长,消除更为缓慢,有长效抑菌效果。     

盐酸多西环素缓释注射液在猪体内的药物动力学

健康猪6头,体质量(17.85±1.3)kg,按拉丁方设计进行单剂量静注、肌注盐酸多西环素注射液(普通制剂)和肌注盐酸多西环素缓释注射液,注射剂量按多西环素计均为20 mg/kg,比较盐酸多西环素缓释注射液和盐酸多西环素注射液在猪体内的药动学特征和生物利用度.用高效液相色谱法测定其血药浓度,试验所得的血药浓度-时间数据采用非房室模型统计矩原理分析处理.猪静注盐酸多西环素注射液的主要药物动力学参数为AUC(108.15±13,25)mg·h·L-1,MRT(5.56±1.08)h,CI(0.19±0.02)L·h-1·kg-1,Vd(ss)(1.04±0.09)L·kg-1,t1/2(4.07±0.65)h.猪肌注盐酸多西环素注射液和盐酸多西环素缓释注射液的主要药物动力学参数分别为MRT(15.18±2.13)h和(22.25±3.49)h;Tmax(1.135±0.44)h和(2.0±0.63)h;Cmax(3.32±0.33)mg·L-1和(3.10±0.29)mg·L-1;AUC(38.91±4.35)mg·h·L-1和(61.72±10.16)mg·h·L-1;F(36.66±7.88)%和(57.66±10.75)%.比较盐酸多西环素注射液和盐酸多西环素缓释注射液的主要药动学参数,除了Cmax以外,MRT、Tmax、AUC、F等主要参数均有显著的统计学意义(P＜0.05).这表明盐酸多西环素缓释注射液肌注后吸收缓慢.消除半衰期延长,临床用药48 h给药1次仍能维持对常见病原菌的有效血药浓度.     

妥拉苏林对静松灵及保定宁诱导的中枢抑制作用的影响

用5只犬经25次实验,初步探讨了妥拉苏林(tolazoline)对静松灵及保定宁的拮抗效应。结果表明,妥拉苏林(静注5 mg/kg)可使静松灵和保定宁麻醉犬的平均起立时间(从静注拮抗剂到自行起立行走的时间),分别由对照组的27.4(肌注静松灵1.5mg/kg)、67.4(肌注静松灵2.0mg/kg)及48.3分钟(肌注保定宁2.5mg/kg),缩短为12.5、17.6和9.5分钟(P<0.05),从而提示妥拉苏林对静松灵或保定宁麻醉犬具有催醒作用。     

磺胺邻二甲氧嘧啶(SDM′)在猪体内的药物动力学研究

SDM′对不同体重的猪采用单剂量给药,并按不同给药途径(静注、肌注、口服)与不 同的药物剂型、剂量分成6个组。给药后在不同时间时采血,然后分析血液中游离磺胺浓度。 通过测定的药时数据进行动力学分析。静注给药各组选用二字模型,肌注、口服给药各组选 用有吸收单室模型描述。 静注给药各组的t~1/_2β和tcp(ther)值,第二组(剂量50mg/kg,体重43.0±4.1kg)分别为 15.15±2.82h,17.98±3.34h;第二组(100mg/kg,11.3±2.5kg)分别为13.44±5.75h, 23.79±12.17h;第三组(100mg/kg,75.5±3.3kg)分别为17.59±2.10h,34.11±4.84h。 肌注给药(50mg/kg,56.0±6.2kg)吸收快而维持有效浓度时间短,Ka值为 2.3269± 1.0742,tcp(ther)值为9.79±2.12h。口服给药吸收慢,有效浓度维持时间较肌注长。胶囊剂 的吸收优于混悬剂,Ka值分别为0.3545±0.1426,0.2747±0.0666,有效浓度维持时间也较 混悬剂长,tcp(ther)值分别为17.93±1.38h,11.02±5.65h。 结果表明,SDM′在临床上有较好的使用价值。以静注给药最好,具有初始浓度高和维持 有效浓度时间长的优点,适用于治疗急性感染。口服和肌注给药仅能维持较低的血药浓度。 在不同体重猪的比较试验中,SDM′在幼猪比大猪分布快、排泄快。 本文还根据单剂量给药的研究,推算多剂量     

妥拉苏林和育亨宾对静松灵及保定宁麻醉羊的催醒实验

通过14只绵羊28次实验,观察到静注妥拉苏林(5mg/kg)可使静松灵(肌注2mg/kg)、保定宁(肌注2mg/kg)麻醉绵羊的平均起立时间(从静注拮抗剂到自行起立行走的时间),由对照的98.6min和95.8min,分别缩短为34.2min和30.4min (P<0.01);静注育亨宾(0.2mg/kg),则分别缩短为65.7min和65.0min(P<0.05)。从而提示,妥拉苏林、育亨宾对静松灵、保定宁麻醉绵羊均有催醒作用,且妥拉苏林优于育亨宾。实验还证明,妥拉苏林和育亨宾对静松灵或保定宁引起的麻醉绵羊的呼吸及心率变化,也有拮抗作用。     

甲砜霉素在感染多杀性巴氏杆菌鸡体内的药物动力学

30只健康杂交肉鸡随机分成3组,每组10只,雌雄各半,分别进行健康鸡静脉注射、健康和巴氏杆菌感染鸡口服给药的药动学研究。静注和口服的给药剂量按体质量分别为15mg/kg和30mg/kg。以反相HPLC测定血浆中甲砜霉素的质量浓度,药物浓度-时间数据用3P97药动学程序软件处理。健康鸡单剂量静注给药后,血药浓度-时间数据符合无吸收二室开放模型,其主要动力学参数分别为:V(c)为(0.58±0.09)L/kg,t1/2α(0.11±0.03)h,t1/2β(0.95±0.18)h,AUC为(11.99±0.90)mg/(L.h),CL(s)为(1.26±0.10)L/(kg.h)。健康鸡和巴氏杆菌感染鸡单剂量口服给药血药浓度-时间数据均符合一级吸收一室开放模型。健康鸡口服给药的主要动力学参数分别为:Lagtime(0.04±0.02)h,t1/2ka(0.16±0.08)h,t1/2ke(1.64±0.22)h,T(peak)(0.57±0.18)h,C(max)(6.34±0.56)mg/L,AUC为(19.02±1.48)mg/(L.h),F为79.32%。巴氏杆菌感染鸡口服给药的主要动力学参数分别为:Lagtime(0.07±0.02)h,t1/2ka(0.54±0.26)h,t1/2ke(1.74±0.27)h,T(peak)(1.31±0.39)h,C(max)(5.28±0.73)mg/L,AUC为(21.75±1.03)mg/(L.h),F90.70%。与健康鸡相比,甲砜霉素在感染鸡的t1/2(ka)、T(peak)和Lag-time显著延长(P0.05或P0.01),且比健康鸡具有更高的生物利用度。但甲砜霉素在巴氏杆菌感染鸡体内的消除速度未受影响。     

甲砜霉素在鸡体内的药动学

20只健康杂交肉鸡,随机分成2组,每组10只,雌雄各半,分别进行静脉注射和口服甲砜霉素给药的药动学研究。静注和口服的给药剂量分别为15、30 mg/kg。以反相HPLC测定血浆中甲砜霉素的浓度,药物浓度-时间数据用3P97药动学程序软件处理。鸡单剂量静注给药后,血药浓度-时间数据符合无吸收二室开放模型,其主要动力学参数分别为:V(c)(0.92&#177;0.01)L/kg,t1/2α(0.27&#177;0.02)h,t1/2β(3.46&#177;0.74)h,AUC(11.67&#177;0.57)mg/(L.h),CL(s)1.29 L/(kg.h)。鸡单剂量口服给药血药浓度-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:Lagtime(0.04&#177;0.01)h,t1/2ka(0.76&#177;0.11)h,t1/2ke(2.16&#177;0.58)h,T(peak)(1.73&#177;0.11)h,C(max)(6.03&#177;0.92)mg/L,AUC(32.43&#177;0.75)mg/(L.h),F(138.58&#177;0.07)%。甲砜霉素在鸡体内的药动学特征表现为分布广泛,消除迅速;口服给药吸收迅速且完全,生物利用度高。     

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.