阳离子A对内毒素诱导兔自由基损伤的保护作用

将56只白兔随机分成3组Ⅰ组为正常对照组,共8只;Ⅱ组为内毒素(endotoxin,ET)处理组,共24只;Ⅲ组为阳离子A(cationA,CA)+ET组,共24只.Ⅰ组静注等量的生理盐水,Ⅱ组静注ET 300 μg/kg,Ⅲ组静注CA 200 mg/kg后,静注ET 300μg/kg.1、2、3、4、5 h后分别采集血液制备血浆样品.2、5 h捕杀Ⅰ组兔4只,Ⅱ、Ⅲ组兔各12只,迅速采集肝脏制备组织匀浆.检测血浆T-AOC、CAT活性和MDA含量,肝GSH、GSH-ST、GSH-Px活性.结果显示Ⅰ组各项指标均保持相对稳定;Ⅱ组MDA含量比Ⅰ组升高(P＜0.01),Ⅲ组MDA含量升高不显著;Ⅱ组T-AOC、CAT活性比Ⅰ组降低(P＜0.01),Ⅲ组显著高于Ⅱ组(1、2、3 h,P＜0.01;4、5 h,P＜0.05);Ⅱ组肝脏GSH和GSH-ST活性显著降低(P＜0.01),第5 h GSH-Px活性降低(P＜0.01),第2 h(P＜0.05);Ⅲ组GSH、GSH-Px(第5 h显著降低)、GSH-ST活性降低不明显.结果提示自由基参与了ET休克的病理过程,CA能有效地保护血浆和肝脏免受自由基的损伤.     

鹿皮蝇蛆对驯鹿抗氧化能力的影响

为了探讨驯鹿鹿皮蝇蛆对驯鹿机体氧化应激的影响,分别对鹿皮蝇蛆感染组和未感染组驯鹿血清中的总超氧化物歧化酶(T-SOD)、一氧化氮(NO)、谷胱甘肽过氧化物酶(GSH-Px)、丙二醛(MDA)、羟自由基(.OH)及总抗氧化能力(T-AOC)进行测定。结果表明鹿皮蝇蛆感染组血清中T-SOD、T-AOC活性、抑制.OH能力及NO含量极显著低于未感染组(P<0.01),血清中GSH-Px活性显著低于未感染组(P<0.05);血清中MDA含量极显著高于未感染组(P<0.01)。说明驯鹿感染鹿皮蝇蛆后,机体清除自由基能力降低,自由基在机体内大量蓄积,导致机体产生氧化应激反应。     

氨基胍对内毒素血症山羊肝线粒体自由基代谢的影响

为探讨氨基胍对内毒素血症山羊肝线粒体自由基代谢的影响,将48只健康山羊随机分为4组,生理盐水(SL)组、内毒素(LPS)组、氨基胍(AG)组和氨基胍(AG LPS)保护组.每组分别取肝组织,提取肝线粒体,检测T-SOD、T-AOC、CAT、GSH-Px和GR活性及MDA含量的变化.结果显示,内毒素血症时山羊肝线粒体中SOD、GSH-Px、GR和CAT活性降低,T-AOC活力下降,MDA含量明显增加,而氨基胍保护组肝线粒体抗氧化酶活性普遍回升,MDA含量明显下降.提示,氨基胍能减轻内毒素血症山羊因脂质过氧化造成的肝线粒体损伤,保护肝线粒体功能.     

连翘酯苷对LPS诱导的肉鸡法氏囊中NO及抗氧化酶活性的影响

本试验研究了连翘酯苷对内毒素(LPS)诱导的肉鸡法氏囊中一氧化氮(NO)、总抗氧化能力(T-AOC)、总超氧化物歧化酶(T-SOD)、还原型谷胱甘肽(GSH)和丙二醛(MDA)含量的影响.结果表明:连翘酯苷组中T-AOC、T-SOD和GSH活性明显升高,与正常组比较差异显著(P＜0.05)；LPS组中NO和MDA含量明显升高,T-AOC、T-SOD和GSH活性明显降低,与正常组比较差异显著(P＜0.05)；连翘酯苷治疗组中NO和MDA含量明显降低,T-AOC、T-SOD和GSH活性明显升高,与LPS组比较差异显著(P＜0.05).研究结果表明:连翘酯苷可提高肉仔鸡抗氧化功能,并且可以抑制由LPS引起的氧化反应.     

肉鸡内毒素血症时血浆(清)抗氧化酶活性的变化及氨基胍对其的影响

将120只30日龄肉鸡(公母各半)随机均分为4组：对照组、内毒素组、氨基胍治疗组(内毒素 氨基胍)、氨基胍组。分别在试验后1、3、5、7、9h每组各宰杀6只。提取血浆(清)，检测血浆(清)中总抗氧化能力(T-AOC)、超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)和谷胱甘肽还原酶(GR)活性以及丙二醛(MDA)含量的变化。结果显示，内毒素血症时总抗氧化能力降低，SOD、GR、GSH-Px的活性降低，MDA含量升高。而在氨基胍治疗组各项指标明显改善。由此表明，肉鸡内毒素血症时存在着明显的脂质过氧化作用，而氨基胍可以明显减轻内毒素所致的自由基诱导的脂质过氧化损伤。     

黄曲霉毒素B1、复方中药和硒对肉鸡肝组织匀浆中自由基代谢的影响

为观察黄曲霉毒素B1(AFB1)对肉鸡肝组织匀浆自由基代谢的变化,并研究复方中药与硒对AFB1的拮抗效应,将10日龄120只试验肉鸡随机分成4组,每组30只,分别为Ⅰ组(对照组)、Ⅱ组(AFB1组:AFB10.2mg/kgBW)、Ⅲ组(AFB10.2mg/kgBW+亚硒酸钠2mgSe/kgDM)和Ⅳ组(AFB10.2mg/kgBW+复方中药20g/kgDM)。分别处理后于17、24、31、38日龄宰杀5只肉鸡,提取肝组织,检测肝组织中的总抗氧化能力(T-AOC)、总超氧化物歧化酶(T-SOD)活性和过氧化氢酶(CAT)及丙二醛(MDA)含量的变化。结果显示,口服AFB1(0.2mg/kgBW)后T-SOD、T-AOC和CAT活性降低(P<0.05),MDA含量明显升高(P<0.05),而复方中药与硒治疗组T-SOD、T-AOC和CAT活性升高(P>0.05或P<0.05),MDA含量明显下降(P>0.05或P<0.05)。证实,由自由基增多而引起的脂质过氧化损伤在肉鸡AFB1慢性中毒发病机理中起着重要的作用,复方中药与硒均可有效降低脂质过氧化造成的损伤。     

氨基胍对内毒素血症肉鸡肝自由基损伤的影响

为了探讨自由基在肉鸡内毒素血症发病机理中的作用,将90只30日龄的肉鸡,公母各半,随机分为生理盐水对照组（A组）、内毒素注射组（B组）和氨基胍治疗组（C组）,每组30只.分别在试验后第1、3、5、7和9 h每组各宰杀6只,提取肝组织,检测肝组织中的总抗氧化能力（T-AOC）、超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Px）和过氧化氢酶（CAT）活性以及丙二醛（MDA）含量的变化.结果显示,内毒素血症时肝组织中SOD、GSH-Px和CAT活性降低,MDA含量明显升高,肝组织中T-AOC下降,而氨基胍治疗组的情况明显好转.证实,由自由基增多而引起的脂质过氧化损伤在肉鸡内毒素血症发病机理中起着重要的作用,氨基胍可有效降低脂质过氧化造成的损伤.     

酵母铬对热应激肉鸡抗氧化性能的影响

本试验旨在研究酵母铬不同添加水平对热应激肉鸡体内抗氧化性能的影响.选用14日龄AA肉仔鸡216只,随机分为6个处理,在基础口粮中分别添加铬0(对照组)、1.0、2.0、3.0、4.0和5.0 mg/kg,每组设3个重复,每重复12只鸡,试验期4周,在热应激条件下测定了28和42日龄肉鸡血清和肝脏组织中抑制羟自由基(·OH)能力、抗超氧阴离子自由基(O2-·)活性、MDA含量、GSH-Px、T-SOD、CAT活性和T-AOC.试验结果表明:3.0、4.0 mg/kg铬添加水平能够显著增强热应激肉鸡血清(28日龄)和肝脏(42日龄)中抑制羟自由基能力(P<0.05),提高血清(28和42日龄)和肝脏组织(42日龄)中抗超氧阴离子自由基活性(P<0.05);减少血清(28和42日龄)和肝脏(28日龄)中MDA生成(P<0.05);显著提高血清(28和42日龄)和肝脏组织(28和42日龄)中GSH-Px活性和T-AOC(P<0.05);极显著提高肝脏组织(28和42日龄)中T-SOD活性(P<0.01);并能提高血清(42日龄)CAT活性(P<0.05).结果显示,日粮添加酵母铬可以提高热应激肉鸡血清和肝脏中抑制羟自由基(·OH)能力、抗超氧阴离子自由基(O2-·)活性,减少MDA生成,并能提高血清和肝脏组织中GSH-Px、T-SOD、CAT活性和T-AOC,日粮中适宜的铬添加水平为3.0 mg/kg. (P<0.05);显著提高血清(28和42日龄)和肝脏组织(28和42日龄)中GSH-Px活性和T-AOC(P<0.05);极显著提高肝脏组织(28和42日龄)中T-SOD活性(P<0.01);并能提高血清(42日龄)CAT活性(P<0.05).结果显示,日粮添加酵母铬可以提高热应激肉鸡血清和肝 中抑制羟自由基(·OH)能力、抗超氧阴离子自由基(O2-·)活性,减少MDA生成,并能提高血清和肝脏组织中GSH-Px、T-SOD、CAT活性和T-AOC,日粮中适宜的铬添加水平为3.0 mg/kg. (P<0.05);显著提高血清(28和42日龄)和肝脏组织(28和42日龄)中GSH-Px活性和T-AOC(P<0.05);极显著提高肝脏组织(28和42日龄)中T-SOD活     

共轭亚油酸对鹅抗氧化功能与脂质过氧化的影响

本文旨在研究不同共轭亚油酸(CLA)添加水平对五龙鹅抗氧化性能与脂质过氧化的影响。选用1日龄五龙鹅192只,随机分为4个处理组,每个处理组48只,设4个重复,每个重复12只。在玉米-豆粕型日粮基础上分别添加CLA(0.0、5.0、15.0和25.0g/kg),以饲喂基础日粮组为对照组,试验期8周,测定并观察其在第2、4、6和8周龄血清中总超氧化物歧化酶(T-SOD)和谷胱甘肽过氧化物酶(GSH-Px)活性、血清及肝脏组织中脂质过氧化物丙二醛(MDA)含量和总抗氧化能力(T-AOC)等各项指标的变化规律。结果表明:日粮添加5.0g/kgCLA时,能够显著提高鹅血清T-SOD活性(第6、8周龄)和血清(第6周龄)及肝脏组织中(第8周龄)T-AOC(P<0.05);添加15.0g/kgCLA,对鹅血清T-SOD,GSH-Px(第6、8周龄)活性及血清及肝脏T-AOC均有一定提高作用;而当添加水平为25.0g/kg时,对T-SOD,GSH-Px活性和T-AOC均有一定降低作用;不同添加水平CLA均能明显降低血清及肝脏中MDA含量(P<0.05)。本试验条件下,5.0g/kgCLA添加组对于提高和改善鹅的抗氧化功能与脂质过氧化状况效果最佳。     

褪黑素对山羊内毒素血症心肌抗氧化能力的影响

为探讨自由基在山羊内毒素血症发病机理中的作用,将48只山羊随机分为生理盐水对照组、内毒素组、褪黑素保护组、褪黑素组,每组12只.分别在处理后3、6 h每组各宰杀6只制备心肌组织匀浆,检测心肌中的总抗氧化能力(T-AOC)、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性以及丙二醛(MDA)含量的变化.结果显示,内毒素血症时山羊心肌中SOD、T-AOC和CAT活性降低,MDA含量明显升高,而褪黑素治疗组则情况明显好转.结果表明,由于自由基的增多而引起的脂质过氧化损伤在山羊内毒素血症发病机理中起着重要的作用,褪黑素可有效拮抗脂质过氧化造成的损伤.     

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.     

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     

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

Tropical Animal Health and Production -     

Evaluation of the Microbiological Status of Milk and Various Structures in Mammary Glands from Naturally Infected Dairy Cows

A knowledge of the microbiological status of milk and of the different structures in the mammary glands has great importance in elucidating the pathogenesis of mammary gland infections. The objective of this study was to evaluate the microbiological status of various structures in the mammary glands from naturally infected dairy cows following slaughter. A total of 94 samples of milk, 184 samples of mammary parenchyma, 168 samples of gland cisterns, and 168 samples of teat cisterns were collected for microbiological examination. Microorganisms were detected in 59.9% of all samples, 67.0% of the milk samples, 70.1% of the mammary parenchymas, 55.9% of the gland cisterns and 48.8% of the teat cistern samples. When all samples were considered, coagulase-negative Staphylococcus were the most prevalent (35.7%) followed by coagulase-positive Staphylococcus (12.2%), Corynebacterium bovis (2.4%), Prototheca sp. (1.9%), and Streptococcus dysgalactiae (1.5%). There was a significantly higher occurrence of microorganisms in the milk and mammary parenchyma compared to the gland cisterns and teat cisterns. This revised version was published online in July 2006 with corrections to the Cover Date.     

Development and survival of free-living stages of gastrointestinal nematodes of sheep and goats on pasture in the Nigerian derived savanna

Four grass plots were sequentially contaminated with goat faeces containing known numbers of unembryonated eggs of predominantly Haemonchus contortus and Trichostrongylus spp. between October 1982 and April 1983. Four other plots were similarly contaminated with sheep faeces between February and May 1987. An additional plot was repeatedly contaminated with sheep faeces from February to April 1987. Populations of free-living stages in faeces and of infective larvae (L₃) in the herbage were subsequently monitored until the end of April and June of 1983 and 1987 respectively. During February and May 1987 two control cultures of sheep faeces were incubated in the laboratory at 25°C–30°C and at a constant temperature of 50°C and the free-living development was also monitored. L₃ developed very readily in the faeces cultured at 25°C–30°C and in those spread on a grass plot in October, at the end of the wet season, but developed less on the plot contaminated in May at the start of the wet season. Worm eggs in faeces deposited on plots during the hot dry season (December to April) or incubated at 50°C died and disintegrated after 24–48 h exposure to the high environmental temperatures. The results indicate that it is unlikely that gastrointestinal nematodes of sheep and goats can develop or survive on open pasture during the dry season in the Nigerian derived savanna zone.