Detection and Pharmacokinetics of Etoricoxib in Thoroughbred Horses

Etoricoxib, a selective inhibitor of cyclooxygenase-2, is used in the treatment of many inflammatory diseases and dental pain in humans. The aim of this study was to determine the pharmacokinetics and metabolism of etoricoxib in horses. Six horses weighing an average of 475 ± 25 kg were administered a single oral dose of etoricoxib at 1 mg/kg body weight. The results show that the drug reached a maximum concentration of 505.2 ± 67.8 ng/mL in 48 minutes after administration. The elimination half-life was calculated to be 10.20 ± 1.30 hours. Mass spectrometric analysis confirmed that etoricoxib is metabolized in horses via the oxidation of its 6′-methyl group to form a hydroxyl methyl etoricoxib which can further be oxidized to form either an acid or be glucuronidated. In addition, the 1′-N terminal of 6′-hydroxymethyl metabolite is oxidized to form the corresponding 1′-N oxide metabolite. The present results have clearly demonstrated that etoricoxib is mainly excreted in urine as metabolites. From these data, it is also possible to postulate a detection time for the metabolites which in turn can assist in the control of illegal use of the drug in horse racing.     

高效氯氰菊酯在甘蓝上的残留动态及风险评估

[目的]研究高效氯氰菊酯在甘蓝上的残留动态和去除效果,为甘蓝的安全食用提供理论依据。[方法]研究不同时间和不同处理方法对高效氯氰菊酯残留量的影响。[结果]高效氯氰菊酯在甘蓝植株上的半衰期为0.98 d;在甘蓝植株中前7 d降解速度较快,随后趋于平衡,消解动态符合一级动力学方程;在国家规定的安全间隔期内采收高效氯氰菊酯单剂的残留超标,即其在施药后的第3天残留量均超过国家规定的标准(1 mg/kg),因国家规定的的安全间隔期为3 d,因此高效氯氰菊酯在秋冬季节的安全间隔期相对有所延长。存放时间越长、水温越高、洗涤剂浓度越大、洗涤浸泡时间越长,供试农药的去除率越高,基本可以保证甘蓝的放心安全使用。[结论]国家应根据季节的不同安全间隔期有所区别,在安全间隔期内采收甘蓝经过各种程序处理后食用是相对安全的。     

Lymphocyte blastogenic responses to inciting food allergens in dogs with food hypersensitivity

Lymphocyte blastogenic responses against food allergens in dogs with food hypersensitivity were evaluated in this study. Eleven dogs with food hypersensitivity, based on food elimination and oral food provocation tests and allergic responses to food allergens, were examined by various tests such as intradermal testing, antigen-specific IgE testing, and lymphocyte blastogenic responses. The number and kinds of food allergens identified as positive by these tests were compared with the offending food allergens that were found in an oral food provocation test. In 9 (82%) of the 11 dogs with food hypersensitivity, there was close agreement for positive allergens between the results of lymphocyte blastogenic responses and oral food provocation test; however, there was little agreement for intradermal and IgE testing of the positive allergens with those of the oral food provocation test (11% and 31%, respectively). In the 9 dogs, the stimulation indices of lymphocyte blastogenic responses increased to 2.0-10.1 upon food provocation but decreased significantly to 0.7-1.4 upon feeding the elimination diet until clinical signs disappeared. These results indicate that lymphocyte blastogenic responses may fluctuate because of exposure to offending food allergens in dogs with food hypersensitivity. Lymphocytes reactive to food allergens may play an important role in the pathogenesis of food hypersensitivity in dogs.     

不同水温下无乳链球菌在尼罗罗非鱼体内的动态分布及其消除规律

本研究以腹腔注射无乳链球菌(Streptococcus agalactiae, WC1535菌株)后的尼罗罗非鱼(Oreochromis niloticus,GIFT strain)为研究对象,研究不同水温下无乳链球菌在尼罗罗非鱼体内的动态分布及消除规律。首先,分析25℃、29℃和33℃3个实验组罗非鱼的感染累积死亡率;其次,对3个实验组罗非鱼进行无乳链球菌的体外分离、培养和计数;然后,分析感染后不同实验组罗非鱼脑、肝脏、脾脏和肾脏组织中无乳链球菌的浓度。结果显示,随着水温的升高罗非鱼的累积死亡率也随之升高,25℃、29℃和33℃组的累积死亡率分别为6.67%、25.56%和78.90%。菌落统计结果显示,随着水温的升高,无乳链球菌在罗非鱼体内的增殖速度加快,同时,单位质量组织(脑、肝脏、脾脏和肾脏)中无乳链球菌的最大载菌量也随之升高。本研究还发现,无乳链球菌在罗非鱼脾脏中的浓度最高,在肾脏中的存活时间最长。综上可知,尼罗罗非鱼感染无乳链球菌后,体内各组织中链球菌的增殖、消除速度均与水温密切相关。本研究为研究无乳链球菌的致病机制奠定基础,也为通过合理调控水温及施药等措施防治尼罗罗非鱼链球菌病的暴发提供科学依据。     

吡喹酮及其主要代谢产物在草鱼体内代谢动力学研究

[目的]研究吡喹酮及其主要代谢产物在草鱼体内的代谢动力学规律。[方法]运用高效液相色谱法(HPLC),研究淡水草鱼在单次口灌给药10 mg/kg剂量条件下,鱼体各组织中吡喹酮(PZQ)及吡喹酮一羟基代谢物(M1)的药动学差异。[结果]草鱼血浆、肠道、肝脏和肾脏内PZQ在各个时间点的药物浓度存在极显著差异(P0.01);PZQ在血浆、肠道、肝脏和肾脏的达峰时间分别为1.0、0.5、1.0和1.0 h,而药物峰浓度为0.41、0.45、0.72和0.44 mg/L,M1在血浆、肠道、肝脏和肾脏的达峰时间分别为48.0、0.5、6.0和48.0 h,而药物峰浓度为0.72、0.45、0.42和0.42 mg/g。这表明PZQ在草鱼体内吸收分布快,M1的达峰时间滞后于PZQ。二者达峰浓度相似表明M1是PZQ在草鱼体内主要代谢物。PZQ在血浆、肠道、肝脏和肾脏的消除半衰期(t_(1/2))分别为16.41、4.77、37.16和8.74 h,M1在血浆、肠道、肝脏和肾脏的消除半衰期(t_(1/2))分别为124、71、246和162 h,其消除半衰期明显比PZQ长,说明在鱼体中M1的残留时间比PZQ更长。[结论]在实际生产中,应注意对M1的检测。     

黄河水化学需氧量测定中氯离子的干扰及消除

[目的]消除黄河水化学需氧量测定中氯离子的干扰。[方法]通过模拟试验的方法量化了氯离子对化学需氧量(COD)测定的干扰程度,并在黄河水实际监测工作中进行了验证。[结果]氯离子对水样COD测定的干扰程度与氯离子含量呈正相关,其影响系数与理论值基本相当。黄河水质监测中,氯离子对COD测定的影响不容忽视,必须加入硫酸汞以消除氯离子的干扰。[结论]该研究可为水体化学需氧量测定中氯离子干扰的消除提供科学方法。     

次氯酸钠防治组培苗污染的研究

[目的]探讨次氯酸钠对植物组培苗污染的防治效果。[方法]以马铃薯和切花菊组培苗为试验材料,在MS培养基中分别加入5、10、20、30和40 mg/L次氯酸钠,分析抑菌剂次氯酸钠对组培苗枯草杆菌污染的防治效果。[结果]经过2～3次转接后,5和10 mg/L次氯酸钠对马铃薯和切花菊组培苗的抑菌效果较好,该浓度处理组2种组培苗均未出现污染,且苗木生长较好,但随着浓度的升高次氯酸钠防治效果明显下降。综合分析认为,次氯酸钠浓度在5～10 mg/L之间是防治马铃薯和切花菊组培苗污染的适宜浓度,可达到消除污染目的,其中适宜的转接周期为5～6 d。[结论]该研究结果为利用次氯酸钠消除枯草杆菌、防治马铃薯及切花菊组培苗污染提供了试验依据。     

掌叶半夏微茎尖培养脱毒和快繁体系的建立

研究了茎尖大小、激素浓度、培养基成分对药用植物掌叶半夏脱毒效果的影响以及影响无病毒苗快速繁殖的因素等,结果表明：茎尖大小是影响茎尖成活和脱毒效果的主要因素,0.2~0.5mm的茎尖培养在MS+6-BA 1.0mg/L+NAA 0.1mg/L+蔗糖30g/L+琼脂7g/L培养基上,成活率为53.3%,病毒脱除率为76.7%,培养基中附加247mg/L NH₄ ⁺可有效提高茎尖成活率至86.7%,同种培养基上继续培养,可一次性成功诱导形成试管苗,移栽成活率高达100%。MS+6-BA 2.0mg/L+NAA 0.5mg/L+GA₃ 0.5mg/L组合最有利于试管茎的形成和发育,从而建立了以掌叶半夏微茎尖为外植体的脱毒和快速繁殖体系。     

植物细胞活性氧及其胞内信号转导

研究表明,活性氧(reactiveoxygenspecies,ROS)有很高的生物学活性,高浓度的活性氧是毒性分子,可以引起细胞内大分子的氧化损伤;低浓度的活性氧则作为普遍存在的信号分子起作用,ROS能诱导细胞防御基因的表达和引起适应性反应。     

内蒙古牙克石市油菜高产栽培技术

油菜是牙克石市主要栽培的作物,提高油菜的产量和品质对促进当地农业的发展和提高人们的生活水平有着重要的作用。经过多年的生产实践和实地调查,并参考国内相关的文献资料,加以整理分析,提出了油菜高产栽培技术。应尽量选择夏翻地播种油菜;如选择春秋翻地播种,首先要保证有足够底墒、杂草基数低、整地质量好的地块。选择青杂2号、青杂3号、青杂5号等优良的品种并进行清选和药剂处理;提出了适宜的播种期和最佳密度,合理的肥料配方;田间科学管理措施,病虫草害的综合防治技术等成套的综合高产栽培技术。此项技术经过在生产上应用,表现出油菜前期长势好、病虫害轻,产量和品质都有明显的提高,获得了较好的效果。