喹乙醇在鸡组织的消除及残留研究

本文报道鸡多次内服（３０ｍｇ／ｋｇ，每隔１２ｈ１次，连用６次）及单剂量内服（１２０ｍｇ／ｋｇ）喹乙醇在肝、肾、肌肉及脂肪４种组织中的消除及残留的研究。用乙睛－乙酸乙酯（３／２，Ｖ／Ｖ）提取组织中的药物，反相高效液相色谱法测定组织中喹乙醇的浓度。色谱条件：Ｃ＿（１８）－ＯＤＳ柱（２５ｃｍ×４．６ｃｍ）；流动相为甲醇－水（１５／８５，Ｖ／Ｖ）；流速１．０ｍ／ｍｉｎ，紫外检测波长２６０ｎｍ。鸡多次内服喹乙醇，于第６次给药后在肝、肾、肌肉及脂肪中药物的消除半衰期分别是４．３２、４．５４、３．３１及３．０３ｈ。若规定组织中喹乙醇的最高残留限量０．００１ｍｇ？ｋｇ为可食用，则休药期应为２．５ｄ。内服单剂量喹乙醇（１２０ｍｇ／ｋｇ）后在肝、肾、肌肉及脂肪中药物的消除半衰期分别是１６．１６、１５．１９、１２．３７及１１．００ｈ，若规定食用组织中喹乙醇的最高残留限量为０．００１ｍｇ／ｋｇ，则休药期应为８．５６。结果表明，鸡内服中毒剂量的喹乙醇（１２０ｍｇ／ｋｇ）显著减慢其在体内的消除，而延长在组织中的消除半衰期及残留时间。     

锥-46的耕牛血药浓度反相HPLC测定方法探索

用惠普ＨＰ１０５０四元泵、ＨＰ１０４０Ｍ二极管阵列检测器和色谱柱ＥｃｏｎｏｓｐｈｅｒｅＣ（１８）（２５０×４．６ｍｍ，５μ）探索了锥－４６的耕牛血药浓度测定条件。检测波长２５２±２ｎｍ，参比波长５５０±２ｎｍ。流动相为甲醇：乙腈：重蒸水＝２０：２５：５５（Ｖ／Ｖ），每３００ｍｌ加入二乙胺１０００μｌ，用磷酸调节至ｐＨ３．５，流速０．６ｍｌ／分。血浆中的锥－４６用磷酸酸化至ｐＨ２．４的甲醇溶液提取，平均提取效率达９９．３３±２．２８％。提取物在６０℃下减压浓缩。平均回收率为９９．４６±６．０７％。本法最低检测浓度为０．１μｇ／ｍｌ。在锥－４６浓度为０．１～１０μｇ／ｍｌ范围内线性良好（相关系数ｒ＝０．９９９９，峰面积＝０．６９２８＋１．５８１×锥－４６ｎｇ数）。锥－４６基本上能与血浆中的杂质成分完全分离。已应用于耕牛体锥－４６的药物代谢动力学的研究。     

乐都驴9项血液生理指标测定

对６８头乐都县本地驴的９项血液生理指标进行测定，结果：ＲＢＣ５．４３±０．８８×１０￣（１２）／Ｌ；ＨＢ１３２．４±１２．５ｇ／Ｌ；ＰＣＶ０．３８±０．０４Ｌ／Ｌ；ＭＣＨ２４．９８±４．１５ｐｇ；ＭＣＶ７１．０１±１１．４８ｆｌ；ＭＣＨＣ３５２．３６±２８．８９ｇ／Ｌ；ＷＢＣ１１．２１±２．５６×１０￣９／Ｌ；ＷＢＣ－ＤＣ中，嗜酸性白细胞１４．９９±６．９０％、嗜碱性白细胞０．０４±０．２１％、嗜中性白细胞４０．８７±９．８６％（内杆状核５．１６±３．９２％、分叶核３５．６６±９．７１％）、淋巴细胞４２．７６±１０．８１％、单核细胞１．２４±１．７６％；ＥＳＲ中，１５ｍｉｎ１１．６４±１５．６４ｍｍ、３０ｍｉｎ２３．７６±１９．５７ｍｍ，４５ｍｉｎ３１．８８±１９．２２ｍｍ，６０ｍｉｎ３５．３８±１８．８７ｍｍ。     

氯羟吡啶在鸡组织中的残留研究

本文报道用高效液相色谱法检测肉鸡肌肉和肝脏组织中氯羟吡啶的残留。肉鸡肌肉和肝脏组织经乙腈提取，用氧化铝柱和葡聚糖凝胶阴离子交换柱净化分离，洗脱液浓缩后用含内标物的甲醇溶解。以磷酸盐缓冲液／乙腈（８５／１５，ｖ／ｖ）作为流动相，苯甲酰胺作为内标物，用ＲＰ－１８柱（２２０×４．６ｍｍ）在紫外波长２７０ｎｍ处检测。将氯羟吡啶以０．０５、０．１０和０．５０μｇ／ｇ分别添加到空白肌肉组织中，测得肌肉组织回收率为８８．０％、９０．４％和９１．６％；以０．１０和０．５０μｇ／ｇ水平添加到肝脏组织中，肝脏组织回收率为８５．４％和９０．２％，变异系数均低于１０％。用该方法测定肌肉和肝脏组织中氯羟吡啶残留的最低检测限分别为０．０２５ｍｇ／ｋｇ和０．０５ｍｇ／ｋｇ。经１２５ｍｇ／ｋｇ氯羟吡啶混料饲喂ＡＡ肉鸡，停药当天（０ｄ）测得肉鸡肌肉和肝脏组织残留量为２．８５ｍｇ／ｋｇ和７．０６ｍｇ／ｋｇ。停药７ｄ时测得肌肉和停药１０ｄ时测得肝脏组织残留量分别低于０．０２５ｍｇ／ｋｇ和０．０５ｍｇ／ｋｇ。     

反相高效液相色谱法测定猪血清中的盐酸环丙沙星

建立反相高效液相色谱（ＲＰ－ＨＰＬＣ）法测定血清中环丙沙星（ＣＰＦＸ）浓度的方法,采用Ｗａｔｅｒｓ ＨＰＬＣ系统,Ｎｏｖａ－ｐａｋ ＯＤＳ柱,以乙腈（含三乙胺的磷酸盐缓冲液）为流动相,检测的波和ｎｍ,血清中ＣＰＦＸ用二氯甲烷萃取。０．０１～１０．２４μｇ／ｍＬ环丙沙星水溶液浓度与色谱峰高奶好线性关系（ｒ＝０．９９９７）,平均回收率大于８０％,批内、批间变异数（ＣＶ）分别小于５％和１０％（ｎ＝６）。     

β-激动剂克伦特罗在猪肝脏和肌肉组织中的残留

本文报道用高效液相色谱法检测β 肾上腺素能激动剂（克伦特罗Ｃｌｅｎｂｕｔｅｒｏｌ）在猪肝脏和背最长肌中的残留量。在肥育猪日粮中添加３ｍｇ／ｋｇ克伦特罗,试验期３０天,停药０、１、２、３、４天屠宰取肝脏和肌肉样。组织经匀浆浓缩提取,色谱条件为：ＣＬＣ ＯＤＳ色谱柱;以２０ｍｍｏｌ／ＬＫＨ２ＰＯ４＋３０μｍｏｌ／ＬＥＤＴＡ（ｐＨ３．９）乙腈＝８２１８（Ｖ／Ｖ）为流动相;紫外检测波长为２４３ｎｍ。结果表明,克伦特罗最低检测限为２ｎｇ／ｇ。停药当天（０天）肝脏和肌肉组织残留量分别为２０８．５ｎｇ／ｇ和１０．０ｎｇ／ｇ。停药后残留量迅速下降,肌肉在停药后第２天即检测不出,而肝脏要到第４天才检测不出。     

克伦特罗在猪体内的生物利用度及药物动力学研究

６头体重４７．００±４．５７ｋｇ（Ｘ±Ｓ）的健康长白和大白杂交猪，拉丁方设计试验，按４ｍｇ／ｋｇ静注、肌注和内服克伦特罗，高效液相色谱法检测血浆中药物浓度，ＭＣＰＫＰ药代动力学程序处理药时数据。静注给药的药代动力学参数是：ｔ１／２α０．６２±０．１２ｈ，ｔ１／２β４．８７±１．５６ｈ，Ｖｄ（ａｒｅａ）４．４８±０．５６ｌ／ｋｇ，ＣｌＢ０．６３±０．１１ｌ／ｋｇ／ｈ，ＡＵＣ６．３９±１．２７μｇ／ｍｌ．ｈ。肌注给药的药动学参数是：ｔ１／２Ｋａ０．２２±０．１０ｈ，ｔ１／２α０．５６±０．２１ｈ，ｔ１／２β４．２５±１．１０ｈ，ｔｍａｘ０．６０±０．１３ｈ，Ｃｍａｘ１．２７±０．３５μｇ／ｍｌ，ＡＵＣ５．４８±１．２９μｇ／ｍｌ．ｈ，Ｆ８５．４０±４．６９％。内服给药的药动学参数是：ｔ１／２Ｋａ０．２８±０．１５ｈ，ｔ１／２Ｋｅ３．１５±０．３６ｈ，ｔｍａｘ１．４６±０．１９ｈ，Ｃｍａｘ０．６５±０．１３μｇ／ｍｌ，ＡＵＣ３．９３±０．９９ｍｇ／ｌ．ｈ，Ｆ６１．０２±１０．９０％。肌注给药的生物利用度与内服比较，差异极显著（Ｐ＜０．０１）。     

烟酸诺氟沙星在猪,鸡体内的组织残留研究

本文报道了烟酸诺氟沙星在猪、鸡体内的组织残留研究结果，猪、鸡均按１０ｍｇ／ｇ剂量给药，采用ＨＰＬＣ法测定肝、肾、肌肉中诺氟沙星浓度。猪肌注给药后７２小时，肾。肌肉中药物浓度已低于仪器最低检测限（０．０５μｇ／ｇ），肝中仍能检出少量药物，浓度为０．３０５±０．１６９μｇ／ｇ；鸡口服给药后４８小时，肝、肾、肌肉中药物浓度均已低于最低检测限。根据本试验结果，建议猪、鸡使用烟酸诺氟沙星后休药期为６天和２天。     

喹乙醇在鸡体内的毒物动力学及其生化毒性和病理学研究

本文对１３只健康ＡＡ鸡单次内服喹乙醇中毒剂量（１２０ｍｇ／ｋｇ）作了毒物动力学分析。用乙腈—乙酸乙酯混合溶剂提取血浆中的喹乙醇,反相高效液相色谱法（ＨＰＬＣ法）测定浓度。喹乙醇内服给药的药时数据适合一级吸收二室开放模型。毒物动力学主要参数为：ｔ１／２Ｋａ０．６３±０．２６ｈ,ｔ１／２α１．１２±０．３４ｈ,ｔ１／２β７．２６±３．０２ｈ,Ｋｅ０．５９±０．１５ｈ－１,Ｔｍａｘ１．１９±０．３１ｈ,Ｃｍａｘ７１．４０±１２．８１μｇ／ｍｌ,ＡＵＣ２５８．１２±３６．１１ｍｇ／Ｌ．ｈ。本试验表明,内服中毒剂量的喹乙醇在ＡＡ鸡体内的吸收、分布均很迅速,但消除缓慢;给药后２４ｈ,血药浓度均高于０．２μｇ／ｍｌ     

高效液相法测定盐酸沙拉沙星制剂的含量

采用高效液相色法测定盐酸沙拉沙星制剂的含量,用Ｎａｖａ－ＰａｋＣ１８１５０＊３．９ｍｍ色谱柱,以０．５ｍｏｌ／Ｌ柠檬酸－０．５ｍｏｌ／Ｌ醋酸铵－乙腈（８０：１０：１８）为流动相,用高氯酸调ＰＨ至２．４;流速１．２ｍｌ／ｍｉｎ,检波波长２７４ｎｍ;线性范围０．２－１．２μｇ（ｒ＝０．９９９９）,平均回收率９９．７％,ＲＳＤ＝０．３％（ｎ＝７）。本方法简便,准确,适用该产品质量控制。     

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.     

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

Tropical Animal Health and Production -     

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.     

Chemotaxis of macrophage in inflammation

Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.     

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