禽多杀性巴氏杆菌感染对麻保沙星在鸡体内药动学特征的影响研究

按每kg体重30万个CFU在鸡胸部肌肉注射接种禽多杀性巴氏杆菌（C48-1），人工诱发鸡急性多杀性巴氏杆菌病。选用90只51-61日龄健康未经多杀性巴氏杆菌苗免疫的岭南黄鸡，18只用作病理模型研究，其余72只随机分为6组，进行静注、肌注及内服麻保沙星（2.5mg/kg）在健康和禽多杀性巴氏杆菌感染鸡的药物动力学研究。用反相高效液相色谱法测定血浆中麻保沙星的浓度。用MCPKP药物动力学程序处理血浆药物浓度-时间数据。麻保沙星在鸡体内的药动学特征是吸收迅速且安全、分布广泛、消除缓慢。急性禽多杀性巴氏杆菌感染除显著延长了肌注及内服麻保沙星的消除并衰期、血药有效浓度维持时间和降低肌注给药的峰浓度外，对其他药动学参数无显著性差异的影响。     

沙拉沙星注射液对人工诱发仔猪大肠杆菌病的临床疗效试验

本试验以5％氟哌酸注射液为对照药物，用沙拉沙星注射液，1.25、2.5及5mg/kg体重3个剂量分别肌肉注射人工诱发大肠杆菌病仔猪，连续用药3d，治愈率分别是85.7%、92.8%、100％，结果表明沙拉沙星注射液对仔猪大肠杆菌病有很好的疗效。     

高效液相色谱法测定麻保沙星溶液的含量

建立了高效液相色谱法测定麻保沙星溶液含量的方法.以23％甲醇溶液溶解并稀释成每1 mL中含麻保沙星0.1 mg的溶液作为供试品,用十八烷基硅烷键合硅胶色谱柱,以醋酸铵高氯酸钠溶液-乙腈(85∶15,V/V)为流动相,检测波长291 nm,流速1.0 mL/min,柱温40℃,进样量10 μL.结果表明,麻保沙星溶液在5～ 200 μg/mL范围内线性良好,线性方程为Y=4.6×104X+3.64 ×105,r=0.9998;平均回收率为98.3％～100.3％,批内变异系数为0.4％ ～ 1.0％,批间变异系数为0.4％ ～0.9％.本方法准确、可靠,适用于麻保沙星溶液的含量测定.     

沙拉沙星对雏鸡大肠杆菌病的疗效研究

本文研究了国产新兽药沙拉沙星对人工感染大肠菌病的疗效。治疗试验用雏鸡240只,随机分为沙拉沙星三个不同剂量组、环丙沙星对照组、阳性对照组和阴性对照组,每组雏鸡40只。当感染鸡出现典型症状时,沙拉沙星三个剂量组、环丙沙星组分别按0.4％、0.2％、0.1％和50 mg·L~(-1)混饮药物,场连续5天。结果表明:沙拉沙星三个剂量组、环丙沙星组对雏鸡大肠杆菌的治愈率分别为95％、87.5％、80％、85％。表明沙拉沙星确为治疗鸡大肠杆菌的理想药物。     

沙拉沙星对鸡细菌病的药效学研究

用两倍试管稀释法测得沙拉沙星对鸡白痢沙门氏菌Ｃ79.13、鸡大肠杆菌Ｏ78、鸡多杀巴氏 杆菌Ｃ４８－１的最小抑菌浓度分别为０．０７８、０．０３９、０．３１２ug/ml,明显 优于对照药物诺氟消水利生及氯霉素。沙拉沙星按高剂量（１００mg．Ｌ＾－１水）、中剂量（５０mg．Ｌ＾－１）水、低剂量（２５mg．Ｌ＾－１水）混饮,连用３天,对人工感染鸡的３种常见细菌病均可取得明显的疗效,３个剂量组对鸡白痢的治愈率分别为１００＾％     

单诺沙星对人工诱发鸡大肠肝菌病的药效试验

根据试管 2倍稀释法测定的单诺沙星及氯霉素对鸡大肠杆菌的最小抑菌浓度 ,对实验性大肠杆菌病鸡进行内服给药 (每隔 12h给药 1次 ,连续 3d)治疗试验。结果表明 ,单诺沙星及氯霉素对鸡大肠杆菌的最小抑菌浓度分别是 0 0 5及 1 6mg/L。单诺沙星以 5mg/kg、氯霉素以40mg/kg的剂量给鸡内服后 ,对大肠杆菌病的治愈率分别为 87 5%及 55 0 %。     

中药方剂对鸡葡萄球菌性关节炎白细胞水平的影响

试验采用右侧关节腔直接接种金黄色葡萄球菌的方法人工复制鸡葡萄球菌性关节炎的病理模型,通过在饲料中添加一定比例的中药方剂,并在接种金黄色葡萄球菌后的第0,4,7,14,21,28天和35天对鸡只进行翼静脉采血,观察白细胞水平的变化规律,从而确定筛选的中药配伍成方剂后对鸡葡萄球菌性关节炎的治疗效果。结果表明,此中药方剂可以明显降低患关节炎病鸡的死亡率,降低幅度为20％,认为对预防和治疗鸡金黄色葡萄球菌性关节炎病有较好作用。     

舒安林对鸡大肠杆菌病药效试验

为验证舒安林对耐药大肠杆菌引起的鸡大肠杆菌病的疗效 ,选取了产酶耐药大肠杆菌进行了体内及体外抑菌实验。结果表明 ,舒安林对金黄色葡萄球菌及大肠杆菌的最小抑菌浓度分别为 2μg/ ml和 4μg/ ml,而氨苄青霉素对金黄色葡萄球菌及大肠杆菌的最小抑菌浓度则分别为12 8μg/ ml和 2 5 6 μg/ ml,且一定剂量的舒安林对人工诱发鸡大肠杆菌病有较好的疗效 ,可显著降低病鸡的死亡率 ,提高增重 ,其疗效明显优于氨苄青霉素     

单诺沙星对鸡败血支原体与大肠杆菌合并感染的药效学研究

采用试管二倍稀释法测得单诺沙星及其对照药物恩诺沙星、泰乐菌素对鸡败血支原体（MG）的最低抑菌浓度分别为0．0625、0.125、0.5mg/L。试验鸡每只左右气囊分别接种MG S6株菌液0.75ml、滴鼻约0.3ml，同时腹腔注射大肠杆菌菌液0.3ml,人工诱发鸡败血支原体与大肠杆菌合并感染的疾病模型。25、50、100mg/L的单诺沙星、500mg／L的恩诺沙星和500mg/L的泰乐菌素连续饮水5d给药，对人工合并感染鸡败血支原体与大肠杆菌病的治愈率分别为93.3%、96.6%、96.6%、93.3%、86.6%，而感染对照组的死亡率为23.3％。单诺沙星及其对照药物组的增重率显著高于感染对照组，并能极显著的降低感染鸡的死亡率、抗体反应阳性率、气囊损伤率及病原再分离率。     

犬皮下注射麻保沙星生物利用度的研究

为了研究麻保沙星在犬皮下给药的生物利用度,将18只犬随机分成2组,按照2mg/kg分别皮下注射或静脉注射麻保沙星后,采血待检,2周后两组交叉给药后,采血。分别在药物注射后5、10、15、30、45min,1、1.5、2,4、6,8、12、24、36、72h时采集血液。血浆通过高效液相色谱法检测药物浓度,用3P97药代动力学软件进行分析。麻保沙星皮下注射的平均药代动力学参数为:t1/2ka=0.19±0.08h;t1/2ke=7.21±1.88h;tmax=0.97±0.29h;Cmax=1.13±0.17μg/mL;AUC=13.13±4.24μg·h/mL;CL=0.17±0.05L/h;V/F=1.63±0.24L/kg。犬皮下注射麻保沙星的绝对生物利用度为66.7%,皮下注射能迅速被吸收且有较高的组织渗透性。     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein     

Avian brood parasitism — a growing research area in behavioral ecology (part Ⅱ)

正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments in     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -