Plasma levels of a low-dose constant-rate-infusion of ketamine and its effect on single and repeated nociceptive stimuli in conscious dogs     

Bergadano A  Andersen OK  Arendt-Nielsen L  Theurillat R  Thormann W  Spadavecchia C 《Veterinary journal (London, England : 1997)》2009,182(2):252-260

This study quantitatively investigated the analgesic action of a low-dose constant-rate-infusion (CRI) of racemic ketamine (as a 0.5 mg kg⁻¹ bolus and at a dose rate of 10 μg kg⁻¹ min⁻¹) in conscious dogs using a nociceptive withdrawal reflex (NWR) and with enantioselective measurement of plasma levels of ketamine and norketamine. Withdrawal reflexes evoked by transcutaneous single and repeated electrical stimulation (10 pulses, 5 Hz) of the digital plantar nerve were recorded from the biceps femoris muscle using surface electromyography.Ketamine did not affect NWR thresholds or the recruitment curves after a single nociceptive stimulation. Temporal summation (as evaluated by repeated stimuli) and the evoked behavioural response scores were however reduced compared to baseline demonstrating the antinociceptive activity of ketamine correlated with the peak plasma concentrations. Thereafter the plasma levels at pseudo-steady-state did not modulate temporal summation. Based on these experimental findings low-dose ketamine CRI cannot be recommended for use as a sole analgesic in the dog.  相似文献   

Florfenicol depletion in edible tissue of rainbow trout,Oncorhynchus mykiss (Walbaum), and sea bream,Sparus aurata L.     

A Di Salvo  G della Rocca  E Terzetti  J Malvisi 《Journal of fish diseases》2013,36(8):685-693

An increase in fish production has consequently brought an increase in infectious diseases in fish farms. The use of chemotherapic drugs is the most effective instrument against common bacterial agents. The number of registered drugs for use in aquaculture is limited and often veterinary practitioners resort to the off‐label use of chemotherapic agents authorized for different food‐producing animal species. Florfenicol is well known for its outstanding effect against various pathogenic bacteria affecting fish, and therefore, it may be a useful drug for off‐label use in aquaculture. The aim of this study was to evaluate the depletion of florfenicol and its major metabolite, florfenicol amine, from the edible tissue of two fish species, rainbow trout and sea bream, following treatment with medicated feed at a dosage of 10 mg kg^?1 of bw day^?1, for 10 consecutive days. At prefixed time points after the end of administration (0.25, 1, 2, 3, 4, 6, 7, 10, 14 and 21 days after treatment), edible tissues (muscle plus adherent skin) from 15 individuals in each group were collected and analysed by HPLC, to determine concentration of the drug in the tissue. On the basis of the obtained concentrations, withdrawal times of florfenicol in the two species were calculated. The results indicate that a drug withdrawal time of 500 °C‐day, as established by Directive 2004/28/EC, for off‐label drug use is more than satisfactory to guarantee the healthiness of fish products against the risk of drug residues.  相似文献   

甲砜霉素在鲤鱼及鲫鱼体内的残留研究   总被引：3，自引：1，他引：2  

韩冰 杨洪波王荻  卢彤岩 《中国农学通报》2013,29(26):25-30

本研究旨在分析甲砜霉素在鲤鱼和鲫鱼体内的残留消除规律并为制定休药期提供依据。按照30 mg/kg的给药量对鲤鱼和鲫鱼连续口灌给药甲砜霉素3天,定时取样,外标法定量,采用高效液相色谱-串联质谱法(HPLC-MS/MS)检测采样组织中甲砜霉素的残留量。结果显示：甲砜霉素在0.1~200 ng/mL范围内有良好的线性关系,相关系数为0.9987。回收率在81.33%~109.72%之间。甲砜霉素在停止给药后鱼体各检测组织中残留量呈下降趋势,在停药25天后,甲砜霉素残留量低于中国与欧盟规定的最高残留限量(MRLs)。根据结果,建议休药期为25天。  相似文献   

Evaluating land subsidence by field survey and D-In SAR technique in Damaneh City,Iran     

GHAZIFARD Akbar 《干旱区科学》2017,9(5):778-789

Based on the data from piezometers, well logs, geophysical surveys and the interferometric synthetic aperture radar(In SAR) technique, this study investigates the main causes of land subsidence in Damaneh City, Iran. The size, openings and direction of fissures were measured by micrometer and compass. The locations of fissures and wall cracks were determined by GPS. The geoelectrical data were used to determine the composition, thickness, depth and shape of lower parts of the aquifer. Groundwater fluctuations were evaluated by available piezometers. The In SAR technique was used to measure land deformation from space and to map the dense changes of surface displacements. The results indicate that the main cause of ground subsidence is the decline of groundwater heads and changes in composition and thickness of compressible lacustrine sediments. The subsidence map obtained from the radar data of ASAR sensor of ENVISAT satellite shows that the subsidence zone is mainly in northern city that is underlain by very thick fine sediments. The subsidence rates from March to December 2005 and from July 2011 to January 2012 are 6.7 and 7.0 cm/a, respectively. The results also show good correlations among the formation of earth features, decline in groundwater head and thickness of fine-grained sediments. We recommend that the groundwater withdrawal for agricultural and industrial sectors should be restricted and urban expansion in the northern part of the city should be constrained.  相似文献   

敌百虫在乌鳢体内和水环境中的代谢动力学及残留研究     

尹文林  姚嘉赟  盛鹏程  徐洋  潘晓艺  蔺凌云  沈锦玉 《安徽农业科学》2017,45(6)

[目的]明确敌百虫在水产养殖中的安全性。[方法]全池泼洒0.5 mg/L敌百虫,采用气相色谱法测定敌百虫在乌鳢体内的代谢动力学和残留消除规律。[结果]乌鳢组织和水样中敌百虫的最低检测限为0.02μg/m L。随着时间的延长,敌百虫在乌鳢血液中的浓度逐渐升高,120 h达最高,为0.072 mg/kg,至360 h时未检出。肌肉中12 h内未检出,24 h浓度为0.023 mg/kg,120 h检出最大浓度0.051 mg/kg,至288 h未检出。肝脏8 h未检出,12 h检出浓度为0.026 mg/kg。使用敌百虫后,乌鳢体内的药物残留量均低于我国的兽药最高残留限量要求,但在养殖水体中的残留时间较长,降解半衰期为35.19 h。[结论]为确保敌百虫使用后对水生态环境及食品安全,建议敌百虫使用后的休药期为150℃·d。  相似文献   

复方天然植物制剂对奶牛回乳效果及调控激素的影响     

沈留红  肖劲邦  巫晓峰  姜思汛  江涛  邓俊良  左之才  余树民  曹随忠 《中国农业科学》2017,50(18):3620-3630

【目的】探究复方天然植物制剂对奶牛回乳效果及回乳期奶牛血清胰岛素(INS)、氢化可的松(HC)、生长激素(GH)和胰岛素生长因子1(IGF-1)含量的影响。【方法】试验于2016年1—6月进行,选择四川省某规模化奶牛场半封闭统一舍饲,体重(582±41)kg、第2—4胎中国荷斯坦奶牛150头。从中选取体况良好,健康,乳房、乳汁均正常,即将进入回乳期,产奶量为(15.42±0.71)kg的妊娠后期即将干乳的健康奶牛80头。随机分为A、B、C、D组,每组20头,均采用逐渐干奶法回乳,回乳开始当天记为第0天,A组为对照组,不饲喂复方天然植物制剂。B、C、D组均从回乳开始第1天,每日上午8:00分别饲喂复方天然植物制剂400、500、600g,回乳完成后停止饲喂复方天然植物制剂。复方天然植物制剂由麦芽,朴硝,升麻,柴胡,香附,薏仁,蚕蜕,白术,黄芩,知母,苏梗,芡实,五味子,蒲公英,甘草等按一定比例组成。分别采集奶牛回乳期第0、1、3、5、7、9和11天尾静脉血,置于未加抗凝剂的离心管中,室温下静置1h,置离心机352×g离心10min,转移上层血清于EP管中,-20℃冻存。采用双抗体夹心酶联免疫吸附技术(ELISA)法检测血清INS、HC、GH和IGF-1含量,并记录回乳期奶牛单日产奶量。【结果】A、B、C、D 4组奶牛回乳时间分别为11、7、5、5天。各组回乳期奶牛血清IGF-1和HC含量均呈下降趋势,且对照组下降趋势较各复方天然植物制剂组慢,复方天然植物制剂组血清IGF-1、HC和GH含量在回乳期后回升,对照组血清INS含量上升趋势较各复方天然植物制剂组慢,第0至1天,各组奶牛血清HC、IGF-1和GH含量差异均不显著(P0.05);第3—7天,A组奶牛血清HC、GH和IGF-1含量极显著高于B、C、D组(P0.01),而血清INS含量极显著低于B、C、D组(P0.01);第9天,A、D组奶牛血清HC含量均显著高于C组(P0.05),A、B组奶牛血清GH和IGF-1含量均极显著低于C、D组(P0.01),A组奶牛血清INS含量极显著低于B、C、D组(P0.01);第11天,A组奶牛血清HC、GH和IGF-1含量极显著低于B、C、D组(P0.01),A组奶牛血清INS显著低于D组(P0.05),但极显著低于B、C组(P0.01);C、D组奶牛血清IGF-1、GH、HC和INS含量在整个回乳期均差异性不显著(P0.05)。在奶牛回乳期,产奶量、HC、GH和IGF-1两两间均呈极显著正相关(P0.01),INS与产奶量、HC、GH和IGF-1均呈极显著负相关(P0.01)。【结论】复方天然植物制剂能显著促进回乳期奶牛回乳,饲喂500g/日复方天然植物制剂,奶牛回乳时间为5d,回乳效果即可达到最佳。回乳期奶牛血清INS、HC、IGF-1含量和产奶量变化两两间均呈极显著相关,IGF-1、GH和HC对奶牛回乳起负向调控功能,而INS对奶牛回乳起正调控作用。  相似文献   

资源禀赋、收入结构与就业特征对农地承包权退出意愿的影响     

楼佳俊  郑雨倩 《贵州农业科学》2017,45(10)

为农地承包权的顺利退出提供参考,对苏州市和宿迁市7个村庄391家农户的调查数据,采用二元logistic回归模型分析农户资源禀赋、收入结构和就业特征对农地承包权退出意愿的影响。结果表明:1)资源禀赋方面,承包地面积、承包地块数、实际经营面积、宅基地面积以及是否发生过土地流转对承包权退出意愿影响不显著,而拥有城镇住房的家庭退出意愿更强烈。2)就业特征方面,农民外出务工时间越长、上班地点离农村越远、从事的职业与农业相关性越弱,则农户退出土地承包权的意愿越强烈,同时接受过非农技巧培训的农户更愿意退出土地承包权。3)收入结构方面,工资性收入所占比重越高则农户退出承包权的意愿越强,而家庭经营性收入占比较高的家庭越不愿退出承包地。  相似文献   

Pharmacokinetics,tissue residues,and ex vivo pharmacodynamics of tylosin against Mycoplasma anatis in ducks     

Sara T. Elazab  Nahla S. Elshater  Yousreya H. Hashem  Seung-Chun Park  Walter H. Hsu 《Journal of veterinary pharmacology and therapeutics》2020,43(1):57-66

The pharmacokinetics of tylosin were investigated in 3 groups of ducks (n = 6). They received a single dose of tylosin (50 mg/kg) by intravenous (IV), intramuscular (IM), and oral administrations, respectively. Plasma samples were collected at various time points to 24 hr post-administration to evaluate tylosin concentration over time. Additionally, tylosin residues in tissues and its withdrawal time were assessed using 30 ducks which received tylosin orally (50 mg/kg) once daily for 5 consecutive days. After IV administration, the volume of distribution, elimination half-life, area under the plasma concentration–time curve, and the total body clearance were 7.07 ± 1.98 L/kg, 2.04 hr, 19.47 µg hr/ml, and 2.82 L hr⁻¹ kg⁻¹, respectively. After IM and oral administrations, the maximum plasma concentrations were 3.70 and 2.75 µg/ml achieved at 1 and 2 hr, and the bioavailability was 93.95% and 75.77%, respectively. The calculated withdrawal periods of tylosin were 13, 8, and 5 days for kidney, liver, and muscle, respectively. For the pharmacodynamic profile, the minimum inhibitory concentration for tylosin against M. anatis strain 1,340 was 1 µg/ml. The calculated optimal oral dose of tylosin against M. anatis in ducks based on the ex vivo pharmacokinetic/pharmacodynamic modeling was 61 mg kg⁻¹ day⁻¹.  相似文献   

盐霉素在肉鸡组织中残留消除规律研究     

王海  侯东军  刘素英  单吉浩 《中国兽药杂志》2005,39(10):13-15

选择250只1日龄"AA"肉鸡,每1 kg饲料中添加70 mg的盐霉素钠,自由采食,混饲至42日龄停药.停药0 h,肉鸡胸肌、肝脏、脂肪和肾脏中盐霉素含量分别为97.17、371.43、154.4和50.33μg/kg,休药48 h后,肉鸡组织中未检出盐霉素,证明国家规定的5 d休药期是合理的.  相似文献   

恩诺沙星及其代谢物在方正银鲫组织中的代谢及消除规律     

罗晶晶  邹荣婕  宋怿  黄会  韩典峰  李佳蔚  任传博  薛敬林  刘慧慧 《中国动物检疫》2019,36(7):95-103

近年来水产养殖中的常用药物恩诺沙星在鲫中的残留问题比较突出,但目前国家未对其在鲫中的休药期作出明确规定。为做到鲫养殖中科学合理使用恩诺沙星,在12~15℃水温条件下,以60mg/kg.b.w.剂量,对体质量为(250±10)g的健康方正银鲫(Carassius auratus gibelio)灌服恩诺沙星;在灌服后0~120d内不间断采样,用高效液相色谱-串联质谱仪检测,研究恩诺沙星及其代谢产物环丙沙星在方正银鲫鳃、血浆、肌肉、皮肤、肝脏和肾脏中的代谢及消除规律,从而为恩诺沙星在方正银鲫中的休药期制定提供参考。结果显示:灌药后,恩诺沙星在方正银鲫血浆、肌肉、肝脏、鳃、肾脏和皮肤中的达峰时间tmax分别为9、18、24、24、48和48h,肾脏、肝脏、肌肉、血浆、鳃和皮肤中的达峰浓度cmax分别为30.490、21.372、18.715、16.636、15.157和11.663mg/kg;皮肤中的消除半衰期t1/2β最大,为338.2h,血浆中最小,为93.303h;代谢产物环丙沙星的代谢及消除趋势与恩诺沙星大致相同,血浆中达峰值产生最早,tmax为18h,肾脏中的峰浓度最大,cmax为547.26μg/kg。结果表明,方正银鲫以单次口灌60mg/kg.b.w.剂量恩诺沙星,皮肤和肌肉中的恩诺沙星和环丙沙星总量需要1200度日才能满足限量要求。本研究为恩诺沙星在鲫鱼养殖中的科学使用提供了数据支撑。  相似文献