牛支原体和牛病毒性腹泻病毒二重二温式PCR检测方法的建立

为建立一种牛支原体(Mycoplasma bovis,MB)和牛病毒性腹泻病毒(Bovine viral diarrhea virus,BVDV)的快速鉴别诊断方法,针对MB的uvr C基因和BVDV的5'端非编码区(5'-UTR)保守基因序列,分别设计两对特异引物,并将三温式PCR扩增程序简化为二个温度梯度,建立了鉴别MB和BVDV的二重二温式PCR方法。该方法能同时扩增MB和BVDV,扩增产物大小分别为412和170 bp。特异性试验结果显示,该方法对参试的所有毒株只扩增MB和BVDV基因组,对其它牛病原体无扩增;敏感性试验结果显示,该方法最低能同时检测到104拷贝的两种目的核酸;干扰性试验结果显示,该方法能同时检测两个模板不同浓度的组合,试验结果不受模板影响。综上,本研究所建立的二重二温式PCR方法特异、敏感、快速、简便,可应用于MB和BVDV临床鉴别诊断和流行病学调查。     

Pharmacokinetics of sanguinarine,chelerythrine, and their metabolites in broiler chickens following oral and intravenous administration

Sanguinarine (SA) and chelerythrine (CHE) are the main active components of the phytogenic livestock feed additive, Sangrovit®. However, little information is available on the pharmacokinetics of Sangrovit® in poultry. The goal of this work was to study the pharmacokinetics of SA, CHE, and their metabolites, dihydrosanguinarine (DHSA) and dihydrochelerythrine (DHCHE), in 10 healthy female broiler chickens following oral (p.o.) administration of Sangrovit® and intravenous (i.v.) administration of a mixture of SA and CHE. The plasma samples were processed using two different simple protein precipitation methods because the parent drugs and metabolites are stable under different pH conditions. The absorption and metabolism of SA following p.o. administration were fast, with half‐life (t_1/2) values of 1.05 ± 0.18 hr and 0.83 ± 0.10 hr for SA and DHSA, respectively. The maximum concentration (C_max) of DHSA (2.49 ± 1.4 μg/L) was higher that of SA (1.89 ± 0.8 μg/L). The area under the concentration vs. time curve (AUC) values for SA and DHSA were 9.92 ± 5.4 and 6.08 ± 3.49 ng/ml hr, respectively. Following i.v. administration, the clearance (CL) of SA was 6.79 ± 0.63 (L·h^?1·kg^?1) with a t_1/2 of 0.34 ± 0.13 hr. The AUC values for DHSA and DHCHE were 7.48 ± 1.05 and 0.52 ± 0.09 (ng/ml hr), respectively. These data suggested that Sangrovit® had low absorption and bioavailability in broiler chickens. The work reported here provides useful information on the pharmacokinetic behavior of Sangrovit® after p.o. and i.v. administration in broiler chickens, which is important for the evaluation of its use in poultry.     

Pharmacokinetics of mequindox and one of its major metabolites in chickens after intravenous, intramuscular and oral administration

Pharmacokinetics of mequindox and one of its major metabolites (M) was determined in chickens after intravenous (i.v.), intramuscular (i.m.) and oral administration of mequindox at a single dose of 10 (i.v. and i.m.) or 20 mg/kg b.w. (oral). Plasma concentration profiles were analyzed by a non-compartmental pharmacokinetic method. Following i.v., i.m. and oral administration, the areas under the plasma concentration-time curve (AUC(0-∞)) were 0.71±0.15, 0.67±0.21, 0.25±0.10 μg h/mL (mequindox) and 37.24±7.98, 36.40±9.16, 86.39±16.01 μg h/mL (M), respectively. The terminal elimination half-lives (t(1/2λz)) were determined to be 0.15±0.06, 0.21±0.09, 0.49±0.23 h (mequindox) and 5.36±0.86, 5.39±0.52, 5.22±0.35 h (M), respectively. The bioavailabilities (F) of mequindox were 89.4% and 16.6% for i.m. and oral administration. Steady-state distribution volume (V(ss)) of 1.20±0.34 L/kg and total body clearance (Cl(B)) of 13.57±2.16 L/kg h were determined for mequindox after i.v. dosing. After single i.m. and oral administration, peak plasma concentrations (C(max)) of 3.04±1.32, 0.36±0.13 μg/mL (mequindox) and 3.81±0.92, 5.99±1.16 μg/mL (M) were observed at t(max) of 0.08±0.02, 0.32±0.12 h (mequindox) and 0.66±0.19, 6.67±1.03 h (M), respectively. The results showed that mequindox was rapidly absorbed after i.m. or p.o. administration and most of mequindox was transformed to metabolites in chickens, with much higher C(max)s and AUCs of metabolite (M) than those of mequindox in plasma.     

桑园病虫害的综合防治技术综论

桑园病虫害的发生及发展状况直接影响桑叶的产量及品质,进而影响到以之作为食物源的家蚕的生长发育、养蚕及制种成绩。因此,桑园病虫害的防治问题值得重视。从现有的桑园病虫害防治技术体系来看,单一的防治方式已经达不到改良和恢复自然昆虫动态平衡的目的了,必须将目前常用的化学防治方法与其它方法结合起来,交替进行,进行综合防治。     

浅谈中国南岭山地树种资源保护

根据中国南岭山地树种资源现状分析了其保护的意义和效益,提出了保护方法、措施及手段。     

购犬应当选择好的繁殖者

当养犬爱好者想给自己挑选一头爱犬时,怎样选择小犬将会是一个至关重要的问题.笔者认为,了解小犬的饲养繁殖者很重要.因为小犬的饲养繁殖者直接关系到犬的质量.……     

柔嫩艾美尔球虫野外株对3种聚醚类离子载体抗生素的敏感性试验

采用鸡体药效试验法测定了柔嫩艾美尔球虫对３种聚醚类离子载体抗生素的敏感性。试验证明，柔嫩艾美尔球虫野外分离株对盐霉素（６６×１０－６）、莫能菌素（１２０×１０－６）和拉沙菌素（１２５×１０－６）产生了耐药性。上述３种药物的抗球虫指数（ＡＣＩ）分别为１４９．３９、１３４．０４和１５６．１１。但这３种药物对柔嫩艾美尔球虫标准株仍然有效     

纳米蒙脱石抑菌性能研究

本文采用快速分散、研磨、高速离心的方法对高纯蒙脱石进行分级,研究普通蒙脱石和纳米蒙脱石抑制黄曲霉菌的效果。结果表明:蒙脱石在水中分散后,逐步由悬浮液转变为凝胶体,当中位径为3.9μm时,抑菌效果较差;中位径为0.92μm时,抑菌效果明显提高;中位径为0.26μm时,抑菌效果最好。     

鸡霍乱流行病学研究

禽霍乱病原菌肌肉注射人工感染成年鸡后,禽霍乱病原菌首先局限于注射部位生长繁殖,其他部位不能检出菌,静脉注射禽霍乱病原菌入血后,血中含菌数很快就迅速下降,出现一个低谷期,然后才不断上升。各组织、器官在任一时刻的含菌数各不相同,肝、脾含菌量最高。在血中可测到禽霍乱病原菌数量增加时,所感染的鸡均出现临床症状,并在几小时后死亡。分析认为,在各好嗜性组织器官中禽霍乱菌的大量繁殖是导致病鸡死亡的关键因素。     

恩诺沙星对鸡大肠杆菌病及葡萄球菌病的药效研究

就畜禽专用氟喹诺酮类抗菌药恩诺沙星对鸡人工感染大肠杆菌病及葡萄球菌病的药效进行了研究。结果表明，恩诺沙星、氯霉素对大肠杆菌Ｏ７８的ＭＩＣ分别为０．０５、１．６０ｍｇ／Ｌ；恩诺沙星、红霉素对金黄色葡萄球菌Ｃ５６０５株的ＭＩＣ分别为０．２、３．２ｍｇ／Ｌ。人工发病试验中，恩诺沙星内服以５、１０、２０ｍｇ／ｋｇ剂量或肌注以２．５、５、１０ｍｇ／ｋｇ剂量，每天给药２次，连用３ｄ，对鸡大肠杆菌病及葡萄球菌病均有较好的疗效，其中对大肠杆菌病的疗效明显优于氯霉素