玉米醇溶蛋白微球制备条件的探索以及体外释药行为研究

以玉米醇溶蛋白（zein）为原料，采用相分离法制备微球，探讨了乙醇的浓度，zein的浓度以及第二溶剂（水）加入的速度对蛋白微球大小的影响；采用压片方法获得了包被模型药物（伊维茵素IVM）的蛋白微球片剂，研究了该微球片剂的体外释放动力学以及释放后微球结构的变化。结果表明：微球粒径大小与乙醇及玉米醇溶蛋白的最终浓度、第二溶剂的加入速度有关。迅速加入第二溶剂才能获得粒径比较均匀的蛋白微球；乙醇的最终浓度在40％时可以获得粒径1μm左右的微球；微球的大小随着zein的最终浓度的增加而增大。该蛋白微球新剂型改善了载药微球悬浮液的稳定性。抑制了释药初期的突释现象。     

一种兽用地美硝唑预混剂的制备及稳定性研究

以地美硝唑为主成分原料,以聚乙二醇6000、倍他环糊精作为主成分的助溶剂,地美硝唑和辅料经过过筛、混合后进行粉碎制得地美硝唑预混剂。该配方的组合为：质量比M（地美硝唑）:M（倍他环糊精）:M(聚乙二醇6000)=2:2:6。研究表明地美硝唑预混剂的溶解度良好,溶解度可达8.0%;按地美硝唑预混剂的质量标准要求检测,合格。该配方组合可以同时实现药物的饮水和拌料给药。在密闭条件下保存,长期试验2年,产品的性状和外观几乎没有改变;地美硝唑含量从初始的100.1%下降至97.5%,有效成分含量下降幅度未超过地美硝唑标示量百分含量的10%。产品质量稳定,符合兽药典的要求。地美硝唑预混剂的配方合理、生产操作简单,产品24个月质量稳定,有效期可暂定为24个月。     

口服地美硝唑预混剂引起肉鸭急性中毒的病例报告

<正>地美硝唑是有效的抗组织滴虫药和抗猪密螺旋体药,对于厌氧菌感染导致的肠炎也有较好治疗作用。服用高剂量的地美硝唑会使大鼠出现短期的神经兴奋症状,但其在水禽(如鸭子)上的不安全应用鲜见报道,现笔者将一例肉鸭口服地美硝唑预混剂引起急性中毒的病例报道如下。1发病情况2015年9月28日某养鸭户饲养的800只肉鸭发病。病鸭刚好2月龄大,体重2~2.5 kg。发病前鸭     

高效液相色谱法检测鸩肌肉组织中地美硝唑及其羟基代谢物

地美硝唑（dimetridazole，DMZ）为硝基咪唑类药物，具有抗原虫和抗菌活性，同时具有很强的抗厌氧菌作用，用于治疗鸡组织滴虫病、猪密螺旋体性痢疾、肠道和全身的厌氧菌感染。但它有致癌、致突变及潜在毒性。地美硝唑的主要代谢物羟基地美硝唑（hydroxy dimetridazole，DMZOH）同样可能有致突变性，欧盟和美国都把地美硝唑列为禁用的兽药，我国规定地美硝唑的MRL为0。国外建立了多种检测动物组织中地美硝唑及其他硝基咪唑类药物的检测方法，主要有气相色谱法、高效液相色谱（HPLC）-电化学检测法、高效液相色谱-紫外法、质谱法等。国内谢凯舟等用HPLC测定地美硝唑在肉鸡组织中的残留，沈建忠等分别建立了检测鸡肉、家禽肌肉组织中硝基咪唑类药物的液相色谱法。有关同时检测DMZ和DMZOH的报道较少，且检测限高。因此建立了测定鸡肌肉组织中DMZ和DMZOH的高效液相色谱法。     

地美硝唑-2,3-二羟基苯甲酸盐的制备及表征

为改善地美硝唑(DMZ)的理化性质，丰富DMZ的晶体形式，试验采用混悬法制备了地美硝唑-2,3-二羟基苯甲酸盐(DMZ-2,3-DHBA),采用冷却结晶-缓慢挥发法制备了其单晶，并通过粉末X射线衍射(PXRD)、单晶X射线衍射(SCXRD)、扫描电子显微镜(SEM)、傅立叶红外光谱(FTIR)、热重分析(TG)和差示扫描量热分析(DSC)对DMZ-2,3-DHBA进行表征分析。结果表明：DMZ-2,3-DHBA为淡黄色粉末，单晶为规则的棱状结晶，该盐属于正交晶系Pbca空间群，晶胞参数为a=14.385 8(19)?,b=13.583 7(19)?,c=26.325 0(5)?,α=β=γ=90°,DMZ-2,3-DHBA的不对称单元中包含2个DMZ分子和2个2,3-二羟基苯甲酸(2,3-DHBA)分子。用扫描电子显微镜下观察DMZ-2,3-DHBA呈表面粗糙的棱柱状，其熔点为146℃。说明试验成功制备了DMZ-2,3-DHBA,可用于后续地美硝唑新盐的稳定性及其他兽用抗菌药物的新晶型研究。     

气相色谱-离子阱串联质谱法同时测定猪肌肉中硝基咪唑类药物残留量

旨在建立测定猪肌肉中地美硝唑、洛硝唑、噻克硝唑、甲硝唑和奥硝唑等硝基咪唑类药物残留的气相色谱一离子阱串联质谱测定法。样品用二氯甲烷提取,盐酸反萃取。盐酸萃取液用磷酸氢二钾碱化,再用二氯甲烷反萃取,萃取液于40℃水浴中旋转真空蒸干。残余物用3mL乙酸乙酯溶解,于40℃水浴氮气吹干,加入N,O-双（三甲基硅烷基）乙酰胺和异辛烷各50pL,50℃衍生60min,进样分析,GC—MS／MS检测,外标法定量。结果表明,5种药物标准液浓度在0．005～1．6μg／mL时,与响应值呈良好线性关系,相关系数均大于0．998。洛硝唑的检测限可达0．2μg／kg,噻克硝唑为O．5μg／kg,地美硝唑、甲硝唑和奥硝唑为1．0μg／kg。空白肌肉组织样品中添加药物浓度在0．2～4．0μg／kg时,5种药物的回收率为74％～82％,日间变异系数均小于13％。表明所建立方法灵敏、准确,可用于检测猪肌肉中硝基咪唑类药物残留。     

用固体分散法提高磺胺嘧啶片溶出速度的研究

为了提高磺胺嘧啶（SD）在水中的溶解度,溶出速度,加速其在体内的崩解,溶出,吸收过程,达到速效,高效的目的,以PEG－6000,尿素等材料为载体,采取溶剂熔融法,制备SD的固体分散,分别测定了固体分散体与原料药的溶解度以及固体分散体片剂和普通片剂的溶出度和溶出速度,固体分散体片剂的溶出度均达到90．0％以上,而普通片剂的最大溶出度为26％,方差分析固体分散体片剂组与普通片剂组具有极显差异（P＜0．01）,固体分散体能显提高SD的溶解度和溶出速度。     

兽药中非法添加硝基咪唑类药物的检查方法

正1适用范围1.1本方法适用于盐酸多西环素可溶性粉和硫酸新霉素可溶性粉中非法添加罗硝唑、甲硝唑、替硝唑、地美硝唑、奥硝唑或异丙硝唑的检查。1.2用于其他兽药制剂中非法添加罗硝唑、甲硝唑、替硝唑、地美硝唑、奥硝唑或异丙硝唑检查时,需进行空白试验和检测限测定。2检查方法照高效液相色谱法(《中国兽药典》一部附录0512)测定。     

高效液相色谱法检测鸡肌肉组织中地美硝唑及其羟基代谢物

地美硝唑(dimetridazole,DMZ)为硝基咪唑类药物,具有抗原虫和抗菌活性,同时具有很强的抗厌氧菌作用,用于治疗鸡组织滴虫病、猪密螺旋体性痢疾、肠道和全身的厌氧菌感染.但它有致癌、致突变及潜在毒性.地美硝唑的主要代谢物羟基地美硝唑(hydroxy dimetridazole,DMZOH)同样可能有致突变性,欧盟和美国都把地美硝唑列为禁用的兽药,我国规定地美硝唑的MRL为0.国外建立了多种检测动物组织中地美硝唑及其他硝基咪唑类药物的检测方法,主要有气相色谱法、高效液相色谱(HPLC)-电化学检测法、高效液相色谱-紫外法、质谱法等.国内谢凯舟等用HPLC测定地美硝唑在肉鸡组织中的残留,沈建忠等分别建立了检测鸡肉、家禽肌肉组织中硝基咪唑类药物的液相色谱法.有关同时检测DMZ和DMZOH的报道较少,且检测限高.因此建立了测定鸡肌肉组织中DMZ和DMZOH的高效液相色谱法.     

膨化颗粒饲料液体植酸酶水溶液真空喷涂工艺参数研究

采用正交试验设计,此文研究了膨化饲料在真空喷涂试验条件下,喷涂液体植酸酶水溶液后的喷涂均匀度、植酸酶水中溶失率。结果表明：①喷涂均匀度最优的工艺参数是：混合时间5min、液体添加量120mL、真空度0．040MPa、释压时间30s;②植酸酶在水中最小溶失率的工艺参数是：混合时间5min、液体添加量130mL、真空度0．036MPa、释压时间90s。最后通过比较在两个最优参数组合条件下的喷涂均匀度和水中溶失率,确定膨化饲料真空后喷涂中添加液体植酸酶水溶液的最优工艺参数是：混合时间5min、液体添加量130mL、真空度0．036MPa、释压时间90s。此条件下的喷涂均匀度变异系数是6．74％、水中溶失率是17．67％。     

Minimal inhibitory concentrations of five antimicrobials against Treponema hyodysenteriae and Treponema innocens

The minimal inhibitory concentrations of carbadox, dimetridazole, lincomycin, ronidazole, and tiamulin against isolates of Treponema hyodysenteriae and Treponema innocens were determined by an agar-dilution method. The results obtained indicated that tiamulin was the most effective antimicrobial in vitro against T. hyodysenteriae, followed by carbadox. Dimetridazole, lincomycin, and ronidazole had poor efficacy in vitro against the T. hyodysenteriae isolates. Isolates of T. innocens were more sensitive to the various antimicrobials. Carbadox and tiamulin were the most effective in vitro, followed by ronidazole, dimetridazole, and lincomycin.     

HPLC同时测定复方二甲硝咪唑可溶性粉中地美硝唑、甲氧苄啶、磺胺对甲氧嘧啶的含量

建立同时测定复方二甲硝咪唑可溶性粉中地美硝唑、甲氧苄啶、磺胺对甲氧嘧啶含量的高效液相色谱法.采用Discovery C18色谱柱(250 mm×4.60 mm,5 μm);以0.1%磷酸溶液-乙腈(90:18)为流动相;检测波长为230 nm;流速为1.0 mL/min;进样量为10 μL.地美硝唑在20μg/mL～1...     

The efficacy of some drugs with known antiprotozoal activity against Histomonas meleagridis in chickens

Nine drugs with known or suspected antiprotozoal activity were tested in vitro, and in vivo for activity against Histomonas meleagridis. The nitroimidazoles dimetridazole, metronidazole, ornidazole, and tinidazole suppressed growth of H. meleagridis in vitro at 10 microg/ml or higher. Paromomycin sulfate, and carbadox were weakly effective at high levels. Quinolinol, mebendazole, diloxanide furoate, and albendazole had no demonstrable efficacy in vitro. Drugs showing some activity in vitro were tested in young chickens inoculated intracloacally with 2 x 10(5) H. meleagridis/bird. Dimetridazole, metronidazole, ornidazole, and tinidazole were highly effective at 200 ppm in feed. Paromomycin sulfate, and carbadox were ineffective in vivo, with no improvement in liver or cecal lesion scores compared to that of infected controls. Thus, the only new entities with efficacy against blackhead disease in vivo were nitroimidazoles, related to the positive control dimetridazole.     

Pharmacokinetics and anti-trichomonal efficacy of a dimetridazole tablet and water-soluble powder in homing pigeons (Columb a livia)

The anti-trichomonal efficacy and pharmacokinetics of dimetridazole were investigated in the homing pigeon (Columba livia) . Dimetridazole was formulated for drinking water medication and as a prolonged-release tablet. To suppress a Trichomonas gallinae infection successfully, medicated drinking water containing dimetridazole (400 mg/L) had to be administered for at least 3 days. A two-day treatment with a dimetridazole tablet (20 mg/tablet) in fasted, as well as in fed, pigeons was shown to be ineffective. After intravenous administration of 20 mg dimetridazole, the drug plasma concentration-time profile fitted a one-compartment open model with a mean half-life of 3.9 h. The absolute bioavailability of the tablet in fasted pigeons was 83.8%. The bioavailability of the tablet administered with food was reduced by 20%. Dimetridazole was rapidly metabolised to (1-methyl-5-nitroimidazol-2-yl)methanol.     

In vitro susceptibility and a new point mutation associated with tylosin-resistance in Japanese canine intestinal spirochetes

The in vitro susceptibilities of six commonly used antimicrobial agents against 29 isolates of intestinal spirochetes isolated from dogs in Japan were examined by the agar dilution technique. In addition, the genetic basis of tylosin resistance in in vitro selected resistant mutants of two reference strains and three tylosin-susceptible field isolates obtained by three successive subcultures on blood agar containing 1 microg/ml of tylosin was investigated. Carbadox was the most active (MIC: < 0.00625) of all the antimicrobial agents. Although all the isolates were susceptible to tylosin, some were resistant to erythromycin. Tiamulin, lincomycin and dimetridazole were also very active against the isolates. All the resistant isolates did not harbor any plasmids. In vitro selected tylosin-resistant mutants of previously tylosin-susceptible isolates showed a new mutation in which their adenine at the base position equivalent to 2062 of 23S rDNA of Escherichia coli has been replaced by cytosine. These findings may both provide guidance towards the proper choice of antimicrobial agents for the treatment of canine intestinal spirochetosis, and add to the understanding of the genetic basis of tylosin resistance.     

沙拉沙星环糊精包合物的制备与体外释放度研究

为了制备沙拉沙星的新剂型,评价其体外释放度,采用响应面法优化沙拉沙星/β-环糊精包合物微囊的制备条件,用扫描电子显微镜(SEC)进行表征试验,对环糊精包合物微囊的粒径和释放度进行评价。响应面法优化后的参数为沙拉沙星和β-环糊精混合液以300 r/min转速在50℃下搅拌4 h,粒径试验表明包合物粒径平均值为1.0μm。体外释放度试验表明,SAR/β-CD包合物在60 min后累积溶出度达到97%左右并保持稳定,物理混合物60 min后累积溶出度仅63%左右,SAR粉剂在60 min后累积溶出率仅74.4%左右。将沙拉沙星成功制备成一种新型包合物制剂,提高了药物的释放性质,对沙拉沙星的推广具有积极意义。     

Effects of Ghrelin on growth hormone secretion from cultured adenohypophysial cells in pigs

To clarify the direct effects of Ghrelin on growth hormone (GH) release from anterior pituitary (AP) cells in pigs, GH-releasing effects of human Ghrelin (hGhrelin) and rat Ghrelin (rGhrelin) on porcine AP cells were compared with GHRH in vitro. The AP cells were obtained from 6-month-old pigs and the cells (2 x 10(5) cells per well) were incubated for 2 h with the peptides after incubating in DMEM for 3 days. hGhrelin and rGhrelin significantly stimulated GH release from the cultured cells at doses of 10(-8) and 10(-7)M (P < 0.05). The rates of increase in GH at 10(-8) and 10(-7)M of hGhrelin were 82.7 and 131.9%, while those with rGhrelin were 43.9 and 79.5%, respectively. GHRH significantly stimulated GH release from the cells at a dose as low as 10(-11)M (P < 0.05), and the response to GHRH was greater than that induced by Ghrelins. In time-course experiments, GHRH continued to increase GH concentrations in media until 120 min after incubation; however, those in media treated with hGhrelin reached a plateau 60 min after incubation, and the maximal value was approximately one third that obtained with GHRH. When hGhrelin (10(-8)M) and GHRH (10(-8)M) were added together, additive effects of both peptides on the release of GH were observed (P < 0.05). Somatostatin (SS, 10(-7)M) significantly blunted GH release induced by hGhrelin (10(-8)M) and GHRH (10(-8)M) (P < 0.05). In the presence of SS, additive effects of hGhrelin and GHRH on the release of GH were observed (P < 0.05). These results show that Ghrelin directly stimulates GH release from anterior pituitary cells in pigs; however, the GH-releasing effect is weaker than that of GHRH in vitro. The present results also show that Ghrelin interacts with GHRH and SS to in the release of GH from porcine adenohypophysial cells.     

The anti-protozoal activity of bronopol on the key life-stages of Ichthyophthirius multifiliis Fouquet, 1876 (Ciliophora)

Pyceze? (Novartis Animal Vaccines Ltd.) is licensed as a veterinary medicine to treat fungal infections in salmon, trout and their eggs. The active ingredient is bronopol, which due to its broad-spectrum activity has the potential to be an effective treatment against other important aquatic pathogens. In this study the efficacy of bronopol against Ichthyophthirius multifiliis was tested both in vitro and in vivo. In vitro trials demonstrated a 30 min exposure to 100 mg L(-1) bronopol killed 51.7% of the infective theronts. In vitro exposure of the protomonts to bronopol (0, 20, 50 and 100 mg L(-1)) for 30 min was observed to kill 0%, 76.2%, 97.2% and 100% respectively. Protomonts surviving treatment, demonstrated delayed development with the time taken from protomont until the release of theronts ranging from 28.3h for 0 mg L(-1) exposure, to 70 h for parasites in 20 and 50 mg L(-1) exposure groups. These concentrations also caused asymmetric cell division of the encysted tomonts. Exposure of encysted tomonts (min. 8 cell stage) to 100 mg L(-1) bronopol for 30 min, killed 50% within this period, with the remainder dying within the subsequent 42 h post exposure. Lower doses of bronopol were less effective in killing encysted tomonts than the higher doses (3.3% of parasites were killed in 20 mg L(-1); 10% in 50 mg L(-1)), but they still delayed theront release significantly (25.7 h for 0 mg L(-1) to 46.2h for parasites exposed to 20-50 mg L(-1)). Long, low dose (1 mg L(-1)) exposure to bronopol was also efficacious against theronts. Survival after 12h was 29% (c.f. 100% in control parasites), and <1% after 24 h exposure (c.f. 74% in control parasites). Theronts surviving these exposures demonstrated reduced infection success compared to control theronts. The findings of this study demonstrate that bronopol (Pyceze?) affects the survival of all free-living stages of I. multifiliis (protomonts, tomont and theronts), thus suggesting that bronopol may serve a useful role in the control of I. multifiliis infections.     

玻璃化冷冻对猪MⅡ卵母细胞皮质颗粒分布及其激活后胚胎发育能力的影响

本实验旨在探讨玻璃化冷冻保存对猪MⅡ期卵母细胞皮质颗粒分布和孤雌激活后早期胚胎发育能力的影响。实验将卵母细胞随机分为对照组、毒性实验组和冷冻组。采用EFS40和EDFS40两种玻璃化冷冻液处理,卵母细胞经恢复后对其进行染色,观察皮质颗粒的分布;并对另一部分卵母细胞实施孤雌激活,观察早期胚胎的发育。结果表明:毒性实验组和冷冻组卵母细胞皮质颗粒部分释放、完全释放的比例无显著差异,但均显著高于对照组(P<0.05)。不同毒性处理组和不同冷冻组间对皮质颗粒的分布无显著差异。与毒性实验组相比,冷冻处理组显著降低皮质颗粒在皮质区分布的比例(P<0.05)。EFS40毒性实验组孤雌激活后的存活率、卵裂率、囊胚发育率均显著高于EDFS40毒性实验组(86.6%vs.75.0%)、(61.8%vs.40.7%)、(30.2%vs.23.5%)(P<0.05)。EFS40冷冻组存活率显著高于EDFS40冷冻组,但均显著低于对照组。结果显示,抗冻保护剂处理和玻璃化冷冻均导致猪卵母细胞皮质颗粒释放,与EDFS40相比采用EFS40较适合猪MⅡ期卵母细胞冷冻保存。     

Non-starch polysaccharides alter interactions between Heterakis gallinarum and Histomonas meleagridis

Nutrition of the host animal may not only influence interactions between the host and its parasites, but also relations between different parasites species residing on the same host. We investigated effects of insoluble and soluble non-starch polysaccharides (NSP) on establishment and development of Heterakis gallinarum in chicken being treated or left untreated against Histomonas meleagridis. Six groups of one-day-old birds were allocated to three diets, two on each diet. The birds were fed ad libitum either a basal diet (CON), or CON+insoluble NSP (I-NSP) or CON+soluble NSP (S-NSP) until an age of 11wk. At an age of 19d, one of each diet groups was prophylactically treated for 9d with dimetridazole (0.05%, w/v) via drinking water against histomonas. The remaining three groups were left un-treated. Two days after starting dimetridazole treatment (at 3wk), each of the 6 groups was divided into two sub-groups. One dimetridazole treated and one dimetridazole un-treated groups of birds on each diet (6 groups) were infected with 200 embryonated eggs of H. gallinarum that were previously harvested from histomonas-carrying H. gallinarum infected chickens. The remaining 6 groups of uninfected birds, either treated or left un-treated against H. meleagridis, served as controls. Worm burdens of infected birds were determined 8wk p.i. Treatment against H. meleagridis significantly increased incidence of H. gallinarum infection and average worm length in all infected groups independent of the diet consumed (p<0.001). An interaction between effects of diet and dimetridazole treatment on worm burden (p<0.001) indicated that the S-NSP diet resulted in lowest worm burden in dimetridazole un-treated birds, whereas it caused the highest worm burden in the treated birds (p<0.05). Furthermore, the treatment resulted in higher worm burdens when compared to un-treated birds on the corresponding diets (p<0.05). Infection with H. gallinarum impaired body weight (BW) of the chicks (p<0.05) and H. meleagridis aggravated this effect (p<0.05). Dimetridazole treated and un-treated uninfected birds developed similar BW (p>0.05). Both NSP supplemented diets resulted in lower (p<0.05) BW when compared with the CON diet, S-NSP being inferior to I-NSP (p<0.05). It is concluded that H. meleagridis harms the definitive host as well as H. gallinarum. Both insoluble and soluble NSP supplemented diets favor H. gallinarum infection while S-NSP additionally intensifies histomonas infection, which then impairs establishment and development of H. gallinarum.