昆明鼠超数排卵影响因素研究

为探讨昆明鼠超数排卵的最佳条件,提高超排效果,比较促性腺激素使用剂量、孕马血清促性腺激素(PMSG)与人绒毛膜促性腺激素(hCG)注射间隔时间、超排小鼠所处发情周期阶段及小鼠周龄等因素对昆明鼠超数排卵结果的影响。PMSG 8IU+hCG 8IU、间隔46h～48h注射组超排效果最好;3周龄、8周龄～10周龄雌鼠较4周龄～7周龄雌鼠超排效果好,小鼠发情间期或发情前期开始超排的效果显著高于发情周期的其他时期。     

Comparative Anthelmintic Activity of Strategic Sustained Low-level Administration of Albendazole in Feed Pellets Compared to Single Doses of Closantel and Tetramisole against Natural Ovine Parasitic Gastroenteritis

The strategic use of single therapeutic doses of closantel, tetramisole or sustained low-level administration of albendazole in feed pellets in controlling naturally acquired parasitic gastroenteritis in sheep was investigated on a farm in semi-arid Rajasthan, India. A total of 303 5- to 6-month-old sheep were divided into three groups. Two groups were dosed with single therapeutic doses of closantel and tetramisole and the third group was given a low-level medication with albendazole through feed pellets for 30 days. Faecal egg counts revealed significantly lower counts (p<0.001) in the group treated with closantel compared to the other two groups. The faecal egg counts in the group receiving sustained low-level albendazole rose after withdrawal of the medication but remained significantly lower than those in the group treated with tetramisole up to 7 weeks after treatment (p<0.05). On the other hand, in the group treated with tetramisole, the mean faecal egg count rose from 3 weeks after treatment and remained continuously higher than those in any other group up to 12 weeks after treatment. The closantel-treated group gained more body weight but the first six-monthly greasy fleece yield was greater in the group treated with medicated pellets. During the first 3 months of the experiment, three animals in the group treated with tetramisole died of parasitic gastroenteritis. Following sustained low-level administration of albendazole in feed pellets, the plasma disposition curve of both the sulphoxide and sulphone metabolites reached its plateau level by day 5 and remained almost constant thereafter. The comparative cost-effectiveness of the three treatment regimes during the first 3 months of treatment was best for the group treated with closantel followed by the group treated with medicated feed pellets.     

环丙沙星和磺胺二甲嘧啶在大菱鲆体内的药代动力学比较

采用高效液相色谱法,在(23.1±0.8)℃水温条件下,对环丙沙星和磺胺二甲嘧啶两种抗菌药物在健康大菱鲆体内的代谢动力学规律进行了比较研究。结果显示,单次口服环丙沙星和磺胺二甲嘧啶后,药物在血浆中的经时过程均符合一级吸收二室开放模型,表达方程分别为CCIP=14.811e-0.337t+4.028e-0.063t-18.839e-0.616t、CSM2=64.981e-0.141t+4.59e-0.004t-69.571e-0.19t;静脉注射这两种药物后,药物在血浆中经时过程均符合无级吸收二室开放模型,表达方程分别为CCIP=21.784e-1.098t+1.514e-0.043t、CSM2=33.028e-5.687t+8.674e-0.013t。口服相同剂量(20 mg/kg)药物后,对血浆的药代动力学参数进行比较,环丙沙星的Tmax(6 h)、Cmax(5.385μg/mL)、t1/2Ka(1.125h)、t1/2α(2.057 h)和t1/2β(11.028 h)均小于磺胺二甲嘧啶给药(8 h、13.990μg/mL、3.647 h、4.923 h和173.407 h),且F(60.57%)大于磺胺二甲嘧啶给药F(47.13%)。证实环丙沙星在大菱鲆体内的吸收、分布、消除速度,达峰时间均快于磺胺二甲嘧啶给药,且比磺胺二甲嘧啶给药吸收完全。根据本实验的结果,环丙沙星和磺胺二甲嘧啶的合理给药方案分别为28.01 mg/kg和18.32 mg/kg,均为每日1次给药,连用3～5 d。     

苦瓜辐射花粉短期保存方法的初步研究

对4个苦瓜品种开花前1d的雄花进行了9种不同方式的短期保存,以探讨苦瓜辐射花粉短期保存方法。研究结果表明,高温、潮湿有利于花粉的散粉,低温、干燥不利花粉的散粉;在15℃,相对湿度43％条件下保存1d的花粉萌发率较高;而保存2～3d的花粉则以4℃,相对湿度为28％的条件为宜。苦瓜未经辐射处理及辐射后花粉的短期保存条件相同。     

饲用复合微生物制剂的使用技术研究

饲用复合微生物制剂是一种新型饲料添加剂,无毒副作用,具有促进动物生长,提高饲料转化率,增强动物机体免疫功能等作用.对产品使用方法、添加剂量以及产品的贮藏方法进行了研究,确定了饲用复合微生物制剂采用直接饲喂,使用时按日粮的0.3%～0.5%添加饲喂最为适宜,产品宜存放在阴凉干燥处.     

复方氟康唑软膏临床药效试验

为研究复方氟康唑软膏对犬耳道真菌、细菌感染的治疗效果,发犬为试验用动物,采用人工感染和自然感染犬,以耳肤灵为对照,进行42d的临床药效研究。人工感染临床试验结果显示,复方氟康唑软膏和耳肤灵对犬耳道感染均有较好的治疗效果,两者无显著性差异(P>0.05);复方氟康唑软膏推荐剂量组和加倍剂量组对耳道感染的治愈率+显效率均为90%,且与空白对照组相比,差异极显著(P<0.01)。自然感染临床药效试验数据表明,耳肤灵和复方氟康唑软膏对真菌、细菌引起的耳道感染的治愈率+显效率均大于90%,且差异不显著(P>0.05),再次验证了复方氟康唑软膏推荐剂量对犬耳道细菌、真菌感染的治疗效果。表明复方氟康唑软膏推荐剂量(0.5mL/耳,1次/d,连续给药4周)可用于犬耳道细菌、真菌感染的治疗,治疗效果较好,可以在临床中推广使用。     

稀土元素对生物体CaM水平调节的剂量效应的研究

从Ca^2 、CaM、Ca^2 -ATP酶3个层次综述了稀土元素对生物体CaM水平调节的剂量效应及其作用机理。     

Pharmacokinetics of Pefloxacin in Goats after Intravenous or Oral Administration

The plasma concentrations and pharmacokinetics of the fluoroquinolone antimicrobial agent pefloxacin, following the administration of a single intravenous (10 mg/kg) or oral (20 mg/kg) dose, were investigated in healthy female goats. The antimicrobial activity in plasma was measured at predetermined times after drug administration by an agar well diffusion microbiological assay, using Escherichia coli (ATCC 25922) as the test organism. Concentrations of the drug 0.25 g/ml were maintained in plasma for up to 6 and 10 h after intravenous (IV) or oral administration of pefloxacin, respectively. The concentration–time data for pefloxacin in plasma after IV or oral administration conformed to two- and one-compartment open models, respectively. Plasma pefloxacin concentrations decreased rapidly during the initial phase after IV injection, with a distribution half-life (t _1/2 ) of 0.10±0.01 h. The terminal phase had a half-life (t _1/2 ) of 1.12±0.21 h. The volume of distribution at steady state (V _dss), mean residence time (MRT) and total systemic clearance (Cl_B) of pefloxacin were 1.08±0.09 L/kg, 1.39±0.23 h and 821±88 (ml/h)/kg, respectively. Following oral administration of pefloxacin, the maximum concentration in the plasma (C _max) was 2.22±0.48 g/ml and the interval from administration until maximum concentration (t _max) was 2.3±0.7 h. The absorption half-life (t _{1/2 ka}), mean absorption time (MAT) and elimination half-life of pefloxacin were 0.82±0.40, 4.2±1.0 and 2.91±0.50 h, respectively. The oral bioavailability of pefloxacin was 42%±5.8%. On the basis of the pharmacokinetic data, a dosage regimen of 20 mg/kg, IV at 8 h intervals or orally twice daily, is suggested for treating infections caused by drug-sensitive pathogens in goats.     

艾蒿精油对朱砂叶螨的生物活性及几种保护酶活性的影响

采用玻片浸渍法和熏蒸法测定了艾蒿精油对朱砂叶螨的生物活性,分析比较了亚致死剂量(LD_(10)、LD_(20)和LD_(30))和致死中量(LD50)处理雌成螨4、8、12、16、20和24 h后体内保护酶和蛋白酶活性的变化。结果表明,经2.0%的艾蒿精油触杀后,雌成螨24、48和72 h的死亡率分别为21.48%、27.41%和77.78%,LC50分别为23.03%、13.25%和0.35%;艾蒿精油对卵的熏蒸作用较对雌成螨更强,对卵和雌成螨的ID50和LD50分别为0.21和8.93μL/L。艾蒿精油处理雌成螨后,螨体内超氧化物歧化酶(SOD)和过氧化物酶(POD)活性被激活,过氧化氢酶(CAT)和蛋白酶活性被抑制。LD_(10)、LD_(20)和LD_(30)处理8 h时,SOD活性分别为对照的1.43、2.29和2.60倍,POD的激活率分别为54.64%、31.96%和5.15%,CAT的抑制率分别为27.03%、20.46%和31.65%,蛋白酶的抑制率分别为21.53%、29.16%和45.09%。表明艾蒿精油对雌成螨的熏蒸作用可破坏体内保护酶的动态平衡和抑制蛋白酶活性,进而影响其正常生理代谢,对螨体产生毒害作用。因此,艾蒿精油对防治朱砂叶螨有一定的开发潜力。     

鸡传染性喉气管炎人工感染试验

为建立人工模拟自然感染途径诱发鸡传染性喉气管炎病理模型,本试验采用80日龄京粉鸡随机分成健康对照组和试验组,试验组又设10-4、10-5、10-6 3个不同稀释度的剂量组,每组20只,将鸡传染性喉气管炎病毒经口腔滴注到鸡喉气管内进行攻毒,观察攻毒结果并统计发病和死亡情况。结果表明,10-4攻毒剂量组发病时间为1～8 d,发病率100％,死亡率10％;10-5攻毒剂量组发病时间为2～8 d,发病率100％,死亡率５％;10-6攻毒剂量组发病时间为4～9 d,发病率90％,死亡率0％。各组鸡均表现张口呼吸,咳出带血黏液的临床症状,剖检后均可见气管粘膜肿胀、出血,其中10-5组比较典型。10-5组经喉气管内滴注可以引起鸡100％发病,潜伏期、临床症状和病理变化典型,并且与自然感染基本一致,可用作鸡传染性喉气管炎病理模型。