环丙沙星在支原体肺炎猪体内的药动学

18头健康杜洛克×长白×大白杂交猪,分3组,每组6头,通过气管内接种含有猪肺炎支原体的病肺悬液复制疾病模型后,以5.0mg/kg静注、肌注及内服给药进行环丙沙星药物动力学研究.高效液相色谱法测定血浆中药物浓度.MCPKP药物动力学程序处理药时数据.结果显示感染猪静注给药的药时数据适合二室开放模型,t1/2α为0.59 h,t1/2β为3.52 h,Vd(area)为3.21 L/kg,ClB为0.645 L/(ks·h).感染猪肌注和内服给药后的药时数据则适合一级吸收一室模型,t1/2ka分别为0.09、0.31 h;tmax分别为0.46、1.41 h;Cmax分别为1.67、0.35 mg/L;F分别为97.30%、34.66%.上述结果表明,支原体性肺炎对环丙沙星静注给药在猪体内的分布有一定影响,但对其消除过程的影响不大;与健康猪比较,感染猪肌注给药的峰浓度、药时曲线下面积及生物利用度均显著提高,而内服给药的峰浓度、药时曲线下面积及生物利用度均显著降低.     

恩诺沙星及其活性代谢物在传染性鼻炎鸡体的药动学

为建立鸡传染性鼻炎的药动学模型,研究了恩诺沙星及其活性代谢物在传染性鼻炎鸡体内的药动学特征.用反向高效液相色谱法测定血浆中的药物浓度,所得恩诺沙星的ci-ti数据用MCPKP程序处理,代谢物环丙沙星的ci-ti数据用代谢物动力学方法处理.结果表明,鸡静注恩诺沙星后的ci-ti数据符合二室开放模型,其主要动力学参数如下:t1/2α(0.25±0.04) h、t1/2β(5.46±0.71) h、Vd(4.21±1.09) L/kg、CLB(0.54±0.11) L/(kg.h)、AUC(19.68±3.50) mg/(L.h).鸡内服恩诺沙星的ci-ti数据,符合有吸收因素二室模型,其主要动力学参数如下:t1/2ka(0.44±0.11) h、t1/2α(1.17±0.40) h、t1/2β(9.24±2.07) h、AUC(12.23±3.68) mg/(L.h)、tmax(1.50±0.29) h、Cmax(1.34±0.44) mg/L、F 62.26%.恩诺沙星在感染鸡体内的动力学特征是吸收迅速、分布广泛、消除缓慢;感染鸡静注与内服恩诺沙星后,代谢物环丙沙星的动力学特征是生成及消除缓慢、分布广泛.鸡传染性鼻炎可使恩诺沙星内服的生物利用度下降,但对恩诺沙星的分布、消除及代谢物的动力学过程无显著影响.     

环丙沙星在内毒素诱导的乳房炎奶山羊药动学及乳汁和组织浓度

将 1 5头健康杂交奶山羊均分成 3组 ,按每千克体重 5mg的剂量分别对大肠杆菌内毒素诱导的乳房炎奶山羊进行静注、肌注和乳房灌注单剂量环丙沙星药动学试验。高效液相色谱法测定血、乳及组织药物浓度 ,血药浓度 -时间数据用 MCPKP药动学程序处理。诱导乳房炎的奶山羊静注给药的药时数据符合二室开放模型 ,主要药动学参数分别为 :t1 /2α为 ( 0 .0 9± 0 .0 1 ) h,t1 /2β为 ( 1 .1 0± 0 .0 9) h,Vd( area) 为 ( 2 .80± 0 .3 0 ) L/kg,Cl B为 ( 1 .3 1± 0 .2 1 ) L/ ( kg·h- 1 ) ,AUC为 ( 3 .88± 0 .58) mg/ ( L· h- 1 )。肌注给药的药时数据符合一级吸收二室开放模型 ,主要药动学参数分别为 :t1 /2 Kα为 ( 0 .0 7± 0 .0 2 ) h,t1 /2α为 ( 0 .3 9± 0 .2 6) h,t1 /2β为 ( 2 .0 7±0 .4 3 ) h,tmax为 ( 0 .2 6± 0 .0 7) h,Cmax为 ( 1 .0 4± 0 .1 3 ) mg/ L,AUC为 ( 2 .3 8± 0 .1 3 ) mg/ ( L· h- 1 ) ,F为61 .3 4 %。与从健康奶山羊获得的药动学参数相比 ,急性乳房炎能显著影响环丙沙星静注给药的体内分布、转运和消除 ,对肌注给药无明显影响 ,乳房灌注给药在炎症乳房内的吸收个体差异较大。急性乳房炎能显著降低环丙沙星全身给药在乳内积聚程度。肌注后炎症乳腺组织内药物浓度在 2、4、6、8     

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。     

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.     

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。     

恩诺沙星在鸡体内的生物利用度试验

将40日龄肉鸡12只,随机分为2组,分别进行了静脉注射、肌肉注射恩诺沙星(10mg/kg)进行药动学研究。血浆样品经甲醇沉淀血浆蛋白,高速离心,用反相高效液相色谱法测定鸡血浆中恩诺沙星的浓度,3P97计算机程序处理静注及肌注的血浆药物浓度-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 (0.45±0.56) h;t1/2β (7.02±1.42) h;C LB (0.38±0.10) L/(kg·h);A U C (23.69±5.56) (mg·h)/L。健康鸡肌注给药的药时数据适合一级吸收二室模型,主要药物动力学参数为:t1/2α (0.60±0.00) h;t1/2β (8.25±1.73) h;tmax (2.44±0.17)h;Cmax (1.44±0.30) m g/L;A U C(20.74±3.80) (mg·h)/L;F为87.54%。恩诺沙星在健康鸡体内的吸收迅速,达到峰值时间短,消除缓慢。     

肉仔鸡静注和内服环丙沙星(ciprofloxacin)的药物动力学

16只健康 AA肉仔鸡 ,随机分成 2组 ,每组 8只 ,按 10 mg/ kg剂量分别进行静注和内服单剂量环丙沙星药动学试验。血浆中药物浓度用高效液相色谱法测定 ,血药浓度 -时间数据用 MCPKP药动学计算机程序处理。结果表明 ,静注给药后的药时数据符合无吸收二室开放模型 ,主要动力学参数分别为 :t1 /2α为 (0 .2 34± 0 .0 49) h,t1 /2β为 (10 .118±0 .2 71) h,VB为 (1.374± 0 .12 4) L/ kg,CLB为 (0 .0 94± 0 .0 0 9) L· kg- 1 · h- 1 ,AUC为 (10 7.0 6 8± 10 .6 40 ) mg· L- 1· h。内服给药后的药时数据符合一级吸收一室开放模型 ,主要动力学参数分别为 :t1 /2 kα为 (0 .114± 0 .0 0 8) h,t1 /2 k为(7.784± 0 .5 14) h,Tp 为 (0 .70 2± 0 .0 31) h,Cmax为 (5 .736± 0 .5 15 ) m g/ L,AUC为 (6 8.6 2 2± 8.147) mg· L- 1· h,F为 (6 4.0 92± 7.6 10 ) %。肉仔鸡静注环丙沙星在其体内消除较慢 ,分布广泛 ;内服给药吸收迅速 ,消除较静注给药快。     

黄牛静注、肌注和内服吡喹酮的药动学与生物利用度

6头成年健康黄牛按10 mg/kg剂量单次快速静注吡喹酮,另6头成年健康黄牛根据交叉试验设计法按10 mg/kg剂量单次肌注、30 mg/kg剂量内服吡喹酮进行药动学与生物利用度试验.利用高效液相色谱法测定血浆中吡喹酮原药的质量浓度,其检测限为25μg/L.房室模型分析表明,静注给药后的药时数据符合无吸收二室开放模型,其分布半衰期(t1/2a)、消除半衰期(t1/2β)、表观分布容积(Vd)、总体清除率(ClB)、药时曲线下面积(AUC)分别为(0.25±0.03)h、(1.28±0.20)h、(2.11±0.38)L/kg、(1.14±0.10)L/(kg·h)和(8.79±0.74)mg/(L·h).肌注的药时数据符合有吸收一室开放模型,主要药动学参数吸收半衰期(t 1/2ka)、消除半衰期(t1/2ke)、药时曲线下面积(AUC)、达峰时间(tmax)、峰浓度(Gmax)和生物利用度(F)分别为(0.40±0.17)h、(4.65±0.91) h、(6.85±1.02)mg/(L·h)、(1.33±0.52)h、(0.83±0.08)mg/L和77.93%.内服给药后符合有吸收一室开放模型,吸收不规则,其药动学参数t 1/2ka、t1/2ke、AUC、tmax、Cmax和F分别为(1.08±0.13)h、(6.81±1.26)h、(8.51±1.78)mg/(L·     

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     

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.     

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.     

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.