洛美沙星对实验性鸡葡萄球菌病的药效研究

为了给兽医临床推广应用国内新近研制的氟喹诺酮类长半减期药物洛美沙星（Ｌｏｍｅｆｌｏｘａｃｉｎ），特别是用洛美沙星防治鸡葡萄球菌病提供依据，首先以试管２倍稀释法测定了洛美沙星及对照药对金黄色葡萄球菌的最小抑菌浓度，然后观察了洛美沙星、环丙沙星、恩诺沙星饮水给药５ｄ对实验性鸡葡萄球菌病的疗效。结果，洛美沙星、环丙沙星、恩诺沙星、诺氟沙星、红霉素对鸡金黄色葡萄球菌Ｃ５６０１１株的最小抑菌浓度分别为１．０、０．１２５、０．２５、１．０、３２ｍｇ／Ｌ。２５、５０、１００ｍｇ／Ｌ洛美沙星饮水给药对鸡葡萄球菌病的治愈率分别为６６．７％、８０．０％、７６．７％，有效率分别为９０．０％、９６．７％、９６．７％。５０ｍｇ／Ｌ环丙沙星、５０ｍｇ／Ｌ恩诺沙星的治愈率则分别为７６．７％、８０．０％，有效率分别为９３．３％、９６．７％。５０、１００ｍｇ／Ｌ洛美沙星及５０ｍｇ／Ｌ恩诺沙星３个饮水给药组的增重显著高于感染对照组。结果表明，洛美沙星饮水给药治疗鸡葡萄球菌病以５０ｍｇ／Ｌ的剂量为宜。     

氧氟沙星对霉形体与大肠杆菌合并感染鸡的药效学研究

以试管两倍稀释法测得氧氟沙星及其对照药物恩诺沙星、洛美沙星和强力霉素对鸡败血霉形体的最小抑菌浓度分别为０．００６２５、０．０２５、０．４和０．４ｍｇ／Ｌ。５０、１００、２００ｍｇ／Ｌ氧氟沙星、５０ｍｇ／Ｌ恩诺沙星、５０ｍｇ／Ｌ洛美沙星和１００ｍｇ／Ｌ强力霉素连续５ｄ饮水给药,对人工合并感染败血霉形体和大肠杆菌病鸡的治愈率分别是９３．３％、９６．７％、９６．７％、１００％、９６．７％和８３．３％,感     

洛美沙星是对实验性鸡葡萄球菌病的药效研究

为了给兽医临床推广应用国内新近研制的氟喹诺酮类长半减期药物－－洛美沙星,特别是用洛美沙星防治鸡葡萄球菌提供依据,首先以试管２倍稀释法测定了洛美沙星及对照药对金黄色葡萄球菌的最小抑菌浓度,然后观察了洛美沙星,环丙沙星、恩诺沙星饮水给药５ｄ对实验性鸡葡萄球菌病的疗效。结果,洛美沙星、环丙沙是生、恩诺沙星、诺氟沙星、红霉素对鸡金黄色葡萄球菌Ｃ５６０１１株的最小抑菌浓度分别为１．０、０．１２５、０．２５、     

三种恩诺沙星盐对人工诱发鸡巴氏杆菌病的疗效比较

采用试管肉汤两倍稀释法,测得乳酸恩诺沙星、盐酸恩诺沙星及恩诺沙星钾对鸡多杀性巴氏杆菌的最小抑菌浓度均为０．０５ｍｇ／Ｌ。按５ｍｇ／ｋｇ恩诺沙星的剂量,分别给人工诱发巴氏杆菌病鸡内服乳酸恩诺沙星、盐酸恩诺沙星及肌注乳酸恩诺沙星、恩诺沙星钾,每１２ｈ给药１次,连续３ｄ。这些药物对鸡巴氏杆菌病的治愈率分别为１００％、９６．７％、１００％,而感染对照鸡的死亡率为１００％。结果表明,上述三种恩诺沙星盐对鸡巴     

氟罗沙星对鸡败血支原体和大肠杆菌混合感染的疗效

以人工诱发鸡败血霉形体和大肠杆菌混合感染模型,评价氟罗沙星的疗效。按每升水加入２５ｍｇ、５０ｍｇ及１００ｍｇ氟罗沙星及５０ｍｇ环丙沙星的用量给病鸡饮水给药,连续５天,对混合感染鸡的治愈率分别是８６．７％、９０．０％、９０．０％及８３．３％,而感染对照组的死亡率为６３．３％;用药组的相对增重率分别为１０１．３％、１０５．７％、１０７．２％及１０２．４％,均显著高于感染对照组（５８５．５％,Ｐ〈０．０１）     

恩诺沙星对鸡大肠杆菌病及葡萄球菌病的药效研究

就畜禽专用氟喹诺酮类抗菌药恩诺沙星对鸡人工感染大肠杆菌病及葡萄球菌病的药效进行了研究。结果表明，恩诺沙星、氯霉素对大肠杆菌Ｏ７８的ＭＩＣ分别为０．０５、１．６０ｍｇ／Ｌ；恩诺沙星、红霉素对金黄色葡萄球菌Ｃ５６０５株的ＭＩＣ分别为０．２、３．２ｍｇ／Ｌ。人工发病试验中，恩诺沙星内服以５、１０、２０ｍｇ／ｋｇ剂量或肌注以２．５、５、１０ｍｇ／ｋｇ剂量，每天给药２次，连用３ｄ，对鸡大肠杆菌病及葡萄球菌病均有较好的疗效，其中对大肠杆菌病的疗效明显优于氯霉素     

氟甲砜霉素对实验性鸡巴氏杆菌病的药效研究

以两倍稀释法测定氟甲砜霉素及甲砜霉素对鸡巴氏杆菌的最小抑菌浓度分别为０．２５μｇ／ｍＬ和１．２５μｇ／ｍＬ。按１０,２０和３０ｍｇ／ｋｇ的氟甲砜霉素及３０ｍｇ／ｋｇ的甲砜霉素分别给实验性巴氏杆菌病患鸡肌注,每天给药一次,共５ｄ。药物对鸡巴氏杆菌病的治愈率分别为９３．３％,１００％,１００％和１００％,而感染对照组鸡全部死亡。用药组与感染对照组间疗效差异极显著     

氧氟沙星饮水治疗鸡败血霉形体—大肠杆菌感染的药代动力学分析

选用３２０只３３日龄石岐杂健康鸡，分成健康对照、感染对照、氧氟沙星中剂量和高剂量４组。感染鸡接种霉形体和大肠杆菌后，中剂量和高剂量组分别以１００ｍｇ／Ｌ和２００ｍｇ／Ｌ氧氟沙星饮水给药，在试验开始后２～５ｄ，每次给药后２ｈ和８ｈ剖杀，采用ＨＰＬＣ测定血药浓度。结果，血药浓度在中剂量组分别为（１．２６±０．３２），（０．７５±０．２３）ｍｇ／Ｌ，高剂量组分别为（１．６８±０．４２），（１．３５±０．０４）ｍｇ／Ｌ，中、高剂量组在给药后２～５ｄ平均血药浓度分别为（１．０１±０．２７），（１．５２±０．２１）ｍｇ／Ｌ。停药后血药消除缓慢，两组ｔ１２分别为３．１１，４．３３ｈ，ＡＵＣ为４．７６，６．４０ｍｇ·Ｌ－１·ｈ－１，Ｔｃｐ（ｔｈｅｒ）为２３．３４，２３．７２ｈ。本研究表明，氧氟沙星饮水给药对鸡霉形体和大肠杆菌合并感染具有显著的临床效果，从经济观点看，饮水给药以５０～１００ｍｇ／Ｌ，每天１次，连续４ｄ为好。     

氧氟沙星对实验性鸡大肠杆菌病的药效研究

以试管肉汤两倍稀释法测得氧氟沙星及氯霉素对鸡大肠杆菌的最小抑菌浓度分别为０．１及１．６ｍｇ／Ｌ，按５，１０和２０ｍｇ／ｋｇ的氧氟沙星及４０ｍｇ／ｋｇ的氯霉素分别给实验性鸡大肠杆菌病患鸡内服，每１２ｈ服药１次，共３ｄ。这些药物对鸡大肠杆菌病的治愈率分别为９０．０％，９３．３％，９６．７％及８３．３％，而感染对照鸡的死亡率为６３．３％。氧氟沙星和氯霉素的增重效果极显著高于感染对照鸡（Ｐ＜０．０１）。     

鬼臼酰肼哌啶腙氮氧自由基抗肿瘤作用的实验观察

鬼臼酰肼哌啶氮氧自由基对体外培养的人红白血病Ｋ５６２细胞及小鼠Ｌ１２１０细胞，用小孔板法在１００．０，５０．０，２５．０，１０．０μｇ／ｍｌ终浓度剂量２４ｈ后，残留率分别为３９．４５％，５８．４３％，７２．３３％，８１．２４％及３４．５５％，５０．３７％，７６．５８％，８０．６４％，对小鼠移植肿瘤Ｈｃｓ用８０ｍｇ／ｋｇ剂量，瘤重抑制率为４０．１３％；用４０．１３％。     

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