托氟沙星纳米乳的制备及其急性毒性研究

拟制备托氟沙星纳米乳,并对其理化性质与急性毒性进行研究。以纳米乳的载药量、稳定性为考察指标,筛选油相、表面活性剂、助溶剂,结合伪三元相图确定纳米乳的最佳配方,制备托氟沙星纳米乳。通过透射电镜、激光粒度分析仪测定纳米乳的微观形态、粒径;用高效液相色谱仪检测药物含量,通过影响因素试验、加速试验、长期试验考察其稳定性与有效期;经小鼠灌胃试验评价其急性毒性。结果显示,托氟沙星纳米乳的最佳配方:托氟沙星1.36%、牛至油3.24%、乳酸2.60%、聚氧乙烯醚-40-氢化蓖麻油25.98%、蒸馏水66.82%。该纳米乳的乳滴呈圆球形,平均粒径为16.16nm,稳定性良好,有效期为24个月。托氟沙星在3~100μg·mL-1浓度范围内与对应的峰面积线性关系良好,纳米乳的平均回收率为99.33%±1.24%,相对标准偏差为1.25%,精密度较高。小鼠灌胃LD5010 000mg·kg-1,最大耐受剂量为39.72g·kg-1。成功制备了托氟沙星纳米乳,为进一步开发纳米级抗菌药物提供理论依据。     

桉叶注射剂体内外抗菌作用研究

考察桉叶注射液体内外抗菌作用。桉叶注射剂体外对金黄色葡萄球菌和链球菌的最低抑菌浓度(M IC)分别为0.004 g/mL和0.008 g/mL,最低杀菌浓度(MBC)分别为0.008 g/mL和0.015 g/mL,对金黄色葡萄球菌的作用明显强于对链球菌。体内抑菌试验中,小白鼠共分4组,均注射1个MLD菌液,1-3组分别为感染前12 h给药、感染同时给药、感染后12 h给药,4组为细菌对照组,结果表明,在感染同时给药效果最佳,且对两种菌人工感染的治疗效果相当。     

中药肠安体内外抗菌作用的研究

中药肠安是由黄连、车钱子等多味中草药组成的复方制剂。具有清热利湿、健脾解毒、涩肠止泻之功效,主要用于防治大肠杆菌引起的仔猪下痢、腹泻等。为了验证中药肠安对大肠杆菌的抑菌效果,通过对大肠杆菌的分离鉴定和对分离菌株进行体内外抗菌作用的研究,为大肠杆菌引起的疾病的     

改良千里光注射液的体内外抗菌作用及安全性研究

分别用三个乙醇浓度进行醇提水沉法渗漉，制备了千里光原液。然后用高浓度乙醇法(除去蛋白蛋)、醇溶液调pH值法(除去鞣质)以及乙醚脱色等步骤，除杂脱色，制备改良千里光注射液并进行了安全性检验、体外抑菌和体内抗感染试验。结果表明，使用78％的乙醇提取、制备的改良千里光注射液对肠炎沙门氏菌、大肠埃希氏菌、金黄色葡萄球菌、溶血性链球菌均有明显的抑制作用，体内抗感染作用显著，而且具有很好的澄明度和安全性。     

改良千里光注射液的体内外抗菌作用及安全性研究

分别用三个乙醇浓度进行醇提水沉法渗漉,制备了千里光原液,然后用高浓度乙醇法（除去蛋白蛋）、醇溶液调PH值法（除去鞣质）以及乙醚脱色等步骤,除杂脱色,制备改良千里光注射液并进行了安全性检验、体外抑菌和体内抗感染试验,结果表明,使用78％的乙醇提取、制备的改良千里光注射液对肠炎沙门氏菌、大肠埃希氏菌、金黄色葡萄球菌、溶血性链球菌均有明显的抑制作用,体内抗感染作用显著,而且具有很好的澄明度和安全性。     

肉桂精油对动物体内外抗菌作用的研究进展

肉桂精油是从肉桂干燥枝、叶、皮中提取出的挥发性物质,含有肉桂醛、丁香酚、芳樟醇、α-松油醇等抗菌活性成分,能够抑杀体内外的金黄色葡萄球菌、大肠杆菌、沙门氏菌等致病菌,提高动物机体抗菌作用。文章综述了肉桂精油抗菌活性成分组成、体内外抗菌作用机制,以期为肉桂精油作为饲料添加剂、抗菌剂应用于养殖业提供参考。     

改良千里光注射液的体内外抗菌作用及安全性

分别用3种不同浓度乙醇进行醇提水沉法渗漉，制备了千里光原液。然后经高浓度乙醇法除去蛋白质、醇溶液调pH值法除去鞣质以及乙醚脱色等步骤进行除杂脱色，制备改良千里光注射液。对改良千里光注射液进行安全性检验、体外抑菌和体内抗感染试验，结果表明，用78％乙醇提取、制备的改良千里光注射液对肠炎沙门氏菌、大肠埃希氏菌、金黄色葡萄球菌、溶血性链球菌均有明显的抑制作用，体内抗感染作用显著，而且具有很好的澄明度和安全性。     

地克珠利纳米乳的体内药效学研究

地克珠利化学名为氯嗪苯乙氰,该药对鸡、火鸡、鸭、鹅、孔雀、鹌鹑、兔等各种动物球虫病具有良好的防治效果。但由于地克珠利的溶解度极低,与饮用水混合后,药物发生沉降,导致动物不能充分饮用到足量的药物,拌料使用时由于地克珠利临床使用剂量低,很难混合均匀,这样势必会影响抗球虫的效果。     

β-内酰胺酶抑制剂舒巴坦与氨苄西林联用的体内外抗菌作用研究

试验观察了β－内酰胺酶抑制剂舒巴坦与氨苄西林联用的体内外协同抗菌作用。结果表明：氨苄西林与舒巴坦联用对5个标准菌株的抗菌活性与氨苄西林相似，对除绿脓杆菌外的6株临床分离菌株的体外抗菌活性较显著高于氨苄西林。临床分离菌株均可产生β－内酰胺酶并可不同程度的水解氨苄西林，在不加入舒巴坦时，β－内酰胺酶对氨苄西林的水解率为57.64%－100%，加入舒巴坦时，β－内酰胺酶对氨苄西林的水解率降低。舒巴坦对临床分离菌株产生的5种β－内酰胺酶均有抑制作用，在1μg/ml时的抑制率为9.35%-67.20%,10μg/ml时为50％－93.19％，显示出明显的抑酶保护作用。氨苄西林与舒巴坦联用对氨苄西林耐药菌株引起的鸡白痢有明显的治疗效果，按5mg/kg肌注的治愈率为91.18%，显著高于氨苄西林混饮，与舒他西林相似。提示二者联用体内体外均有协同抗菌作用，值得进一步研究。     

复方氧氟沙星注射液的体内外抗菌试验

本文测定了氧氟沙星（OFL）、鱼腥草素钠（HOU）和复方氧氟沙星注射液对大肠杆菌、金黄色葡萄球菌和伤寒沙门氏菌的体外抗菌活性,以及氧氟沙星和鱼腥草素钠的联合抗菌作用,同时还进行了复方氧氟沙星注射液对试验性大肠杆菌感染小鼠的保护性试验。结果表明：复方氧氟沙星注射液抗菌力强于单用氧氟沙星或者鱼腥草素钠,氧氟沙星和鱼腥苹素钠联合应用对金黄色葡萄球菌具有相加作用;复方氧氟沙星注射液对试验性大肠杆菌感染小鼠具有较好的保护作用（P〈0．01）。     

硫酸头孢喹肟混悬剂的质量检验及体外抑菌实验

对自制的硫酸头孢喹肟混悬剂进行质量检验和体外抑菌实验.按照筛选出的配方,应用分散法制备硫酸头孢喹肟混悬型制剂,检验混悬剂的质量并针对临床分离的奶牛乳房炎混合菌株进行体外抑菌实验.结果表明:制得的硫酸头孢喹肟混悬剂符合国家质量标准要求,体外抑菌实验效果明显.     

硫酸头孢喹诺混悬剂的质量检验及体外抑菌实验

对自制的硫酸头孢喹肟混悬剂进行质量检验和体外抑菌实验。按照筛选出的配方,应用分散法制备硫酸头孢喹肟混悬型制剂,检验混悬剂的质量并针对临床分离的奶牛乳房炎混合菌株进行体外抑菌实验。结果表明：制得的硫酸头孢喹肟混悬剂符合国家质量标准要求,体外抑菌实验效果明显。     

Influence of Cysteamine on In Vitro Maturation, In Vitro and In Vivo Fertilization of Equine Oocytes

The effect of cysteamine on in vitro nuclear and cytoplasmic maturation of equine oocytes collected by transvaginal ultrasound guided follicular aspiration was assessed. Oocytes were matured in vitro with (cysteamine group) or without (control group) cysteamine. The nuclear stage after DNA Hoechst staining, penetration rates after two different in vitro fertilization (IVF) techniques (IVF media with ionophore and Hepes buffer with heparin) and the embryo yield following oocyte intra-oviductal transfer were used as a criterion for assessing nuclear and cytoplasmic maturation, respectively. Contrary to the data described in other domestic species, there was no effect of cysteamine on in vitro nuclear maturation, IVF or in vivo embryonic development under our conditions. Ovum pick up yields (52%) and maturation rates (control group: 47% and cysteamine group: 55%) were similar to those previously reported. From 57 oocytes transferred to the oviduct in each group, the number of embryos collected was 10 (17%) in the control group and five in the cysteamine group (9%). Those two percentages were not statistically different (p > 0.05). No effect of IVF technique was seen on the success rate (6%) in each group.     

Exposure Time‐Dependent Bactericidal Activities of Amoxicillin Against Actinobacillus pleuropneumoniae; an In Vitro and In Vivo Pharmacodynamic Model

The pharmacodynamic effects of amoxicillin against Actinobacillus pleuropneumoniae at exposure concentration above and below minimum inhibitory concentration (MIC) were evaluated in both in vitro and in vivo. In vitro, the growth and morphological change of A. pleuropneumoniae in culture medium was observed. In vivo, the efficacy of amoxicillin on experimentally induced A. pleuropneumoniae infection in disease‐free pigs was evaluated. Fifteen pigs were divided into three groups (n = 5 per group). After the onset of clinical respiratory disease symptoms, 6 h post‐infection, amoxicillin sustained‐release injectable formulation was injected intramuscularly at 7.5 mg/kg/day (group I) and 15 mg/kg/day (group II). Then the serum concentration of amoxicillin was measured. An untreated infected group served as controls. In each amoxicillin administration group, if symptoms were not absent after 48 h, the pig was injected with the amoxicillin sustained‐release injectable formulation again using the same dosage. In vitro, the growth of A. pleuropneumoniae inhibited by amoxicillin exposure at the concentration above the MIC (1.28 × MIC), and the inhibition time was in directly proportion to the time of amoxicillin exposure. Moreover, all the cells were lysed. Whereas the bacterial growth inhibition at the amoxicillin exposure concentration below the MIC (0.25 × MIC) was not done, and the shape of cells were normal or long filamentous. In vivo, the group I clinical and pathological score was higher than the group II, and the group I weight gain was significantly less than the group II. Performance with respect to weight gain corresponded with clinical signs. The infected control group was severely affected with an 80% (4/5) mortality rate 24–96 h post‐challenge. The duration of time above MIC (T > MIC) of serum amoxicillin concentration in the group I was less than group II. The present studies suggest that amoxicillin has exposure time‐dependent bactericidal activity against A. pleuropneumoniae.     

硫酸安普霉素与其他药物配伍的体外抑菌试验

为了解硫酸安普霉素与其他抗菌药物配伍对兽医临床常见病原微生物的作用,应用试管二倍稀释法和杯碟法进行了体外抑菌实验,测定了硫酸安普霉素与9种抗菌药物配伍对猪、鸡大肠杆菌的抑菌圈和最小抑菌浓度。结果表明,硫酸安普霉素与青霉素、阿莫西林、强力霉素、硫氰酸红霉素等配伍对猪大肠杆菌具有一定的协同抗菌作用,与TMP、青霉素、阿莫西林、强力霉素、硫氰酸红霉素等配伍对鸡大肠杆菌具有一定的协同抗菌作用。     

家蝇抗菌肽提取及对鸡大肠杆菌病药效试验

体外抑菌试验结果证明抗菌肽对O1型血清大肠杆菌的药敏抑菌圈直径为19.3±0.32mm,以O1型大肠杆菌感染14日龄岭南黄肉用雏鸡,24 h后分别用抗菌肽高、中、低剂量及环丙沙星混饮给药,以比较其疗效。通过临床观察、尸体解剖、细菌检验结果表明,试验药物组与感染对照组差异极显著(P<0.01),即试验药物对鸡大肠杆菌病有良好疗效;抗菌肽高、中剂量与环丙沙星疗效相当(P>0.05),且不影响鸡只的正常增重(P>0.05)。     

Cephalothin and Cefazolin In Vitro Antibacterial Activity and Pharmacokinetics in Dogs

The periods of time that cephalothin and cefazolin serum concentration remained above minimum inhibitory concentration (MIC) for beta hemolytic, coagulase positive staphylococcal, and Escherichia coli clinical isolates were compared. Cephalothin and cefazolin were similarly very effective in vitro against staphylococcal isolates, with an MIC₉₀ of 0.12 μg/mL and 0.25 μg/mL, respectively. In contrast, cefazolin was more effective than cephalothin against E coli isolates; the cefazolin MIC₉₀ for E coli was 16 μg/mL and for cephalothin 64 μg/mL. Cefazolin (20 mg/kg intravenously [IV]) serum concentration remained more than MIC₉₀ for E coli isolates significantly longer than serum concentration of cephalothin (40 mg/kg IV) ( P <.001).