甲硝唑对地塞米松预处理鸡免疫功能的影响

对地塞米松预处理鸡投以10mg／kg剂量的甲硝唑，观察后者对前者作用的影响。结果表明：地塞米松明显抑制由伴刀豆球蛋白A(ConA)引起的鸡外周血淋巴细胞(PBL)产生IL-2活性，而甲硝唑对这种抑制作用有显著的拮抗作用；地塞米松能抑制鸡对绵羊红细胞(SRBC)悬液和牛血清白蛋白(BSA)两种胸腺依赖性抗原的免疫应答和对布鲁氏菌非胸腺依赖性抗原的抗体应答，但甲硝唑会逆转这种抑制作用；甲硝唑能封闭地塞米松对补体产生的抑制作用。对比实验结果同时表明，在拮抗地塞米松对鸡免疫功能负面影响方面，左旋咪唑与甲硝唑作用非常类似。     

西咪替丁对鸡离体外周血淋巴细胞增殖的作用

本试验系统观察了西咪替丁对离体鸡外周血淋巴细胞（ＰＢＬ）增殖及ＣｏａＡ诱导细胞（ＣＩＣ）活性的作用;西咪替丁以剂量依赖性方式促进鸡ＰＢＬ的增殖;低浓度与ＣｏｎＡ对促进鸡ＰＢＬ增殖无协同作用,但高浓度与ＣｏｎＡ呈现协同途径地ＬＰＳ激活鸡ＰＢＬ具有明显促增殖作用;逆转磷酸组胺对ＣｏｎＡ激活鸡ＰＢＬ增殖的抑制作用;损坏抗肾上腺素对ＣｏｎＡ激活鸡ＰＢＬ增殖的抑制作用,可拮抗氢化可的松对ＬＰＳ激活鸡ＰＢＬ增     

西咪替丁对鸡细胞和体液免疫功能的作用

观察了西咪替丁在左旋咪唑在鸡细胞和体液免疫功能的作用。对２８日龄鸡每天分别按２．５、１０．０、１００．０和４００．０ｍｇ／ｋｇ体重西咪替丁或２．５、１０．０ｍｇ／ｋｇ体重左旋咪唑钦水给药,连用３ｄ后再分别肌肉注射绵羊细胞（ＳＲＢＣ）和牛血清白蛋白（ＢＳＡ）或布鲁氏菌（ＢＡ）抗原。测定外周血淋巴细胞转化率和ＣＤ４＾＋／ＣＤ８＾＋淋巴细胞比值;测定血清ＳＲＢＣ、ＢＳＡ、ＢＡ抗体效价和血清补体总活性。结     

西咪替丁对鸡回忆性体液免疫应答反应的作用

枯试验系统观察了西咪替丁对鸡回忆性体液免疫应答反应的作用，并与同类咪唑类化合物左旋咪只进行了比较，28日龄鸡，免疫注射绵羊红细胞＋牛血清白蛋白（SRBC＋BSA）悬液，或稀释的布氏杆菌（BA）抗原。56日龄时，以10．0、100．0mg/kg西咪替丁或10．0mg/kg左旋咪唑饮水给药，连用3天，给药第二天同时进行2次免疫注射。结果表明西咪替丁（10．0－100mg/kg)可使二次免疫鸡体内对颗粒性胸腺依赖性抗原SRBC和非胸腺依赖性抗原BA抗体滴度回忆性免疫应答反应明升高，但使鸡对可溶性胸腺依赖性抗原BSA抗体滴回忆性免疫应答反应明显降低。与西咪替丁比较，左旋咪唑（10．0mg/kg)也存在着非常类似的作用。     

对EDS—76病毒快速检测方法的研究

用平板红细胞凝集（ＨＡ）试验对鸡产蛋下降综合症（ＥＤＳ－７６）病毒进行了快速定性检测，并与微量ＨＡ试验进行了对比。结果表明，当病毒ＨＡ滴度在５×２＾１２及其以上时，在１０－２５℃范围内于半分钟可与１０％鸡红细胞（ＲＢＣ）发生极明显的大片凝集。当病毒ＨＡ滴度在５×２＾１０以下时，则凝集片明显较小，且反应时间在２分钟以上。这种凝集现象可被ＥＤＳ－７６阳性血清特异性抑制。此法可用于对大批量样品中高效价病     

抗原捕捉ELISA与常规方法滴定IBDV的比较

作者建立了两种抗原捕捉酶联免疫吸附试验方法（多抗和单抗ＡＣ－ＥＬＩＳＡ），用于滴定用不同宿主系统增殖的传染性氏囊毒病，这些宿主系统包括ＢＧＭ－７０传代细胞系。鸡胚成纤维细胞和鸡法氏囊，两种检测方法都有较高的特异性，但是多克隆ＡＣ－ＥＬＩＳＡ比单克ＡＣ－ＥＬＩＳＡ更加敏感（Ｐ〈０．０５），结果还表明，滴定ＩＢＤＶ抗原的常规方法（细胞培养物和鸡胚）比多抗ＡＣ－ＥＬＩＳＡ更敏感。     

斑点免疫金银染色法检测鸡传染性支气管炎病毒抗原的研究

用建立的斑点免疫金银染色（Ｄｏｔ－ＩＧＳＳ）法检测鸡传染性支气管炎病毒（ＩＢＶ）抗原,确定兔抗ＩＢＶ血清工作浓度为１：４００,ＳＰＡ－胶体金探针的工作浓度为１：８０,该法对纯化ＩＢＶ抗原的最低检出量为０．４３１４ｎｇ／点,用Ｄｏｔ－ＩＧＳＳ与斑点酶联免疫吸附试验（Ｄｏｔ－ＥＬＩＳＡ）同时检测１５只人工感染ＩＢＶ鸡的气管,肺,肾病科,ＩＢＶ阳性检出率均为１００％,对３２份疑似ＩＢＶ感染鸡病料检测,Ｉ     

应用间接免疫荧光法检测鸡传染性贫血病病毒抗体的研究

用鸡传染性贫血病病毒（ＣＩＡＶ）ＭＳＢＩ－ＴＫ５８０３毒株感染的ＭＤＣＣ－ＭＳＢ；细胞涂片为抗原，建立了检测ＣＩＡＶ抗体的间接免疫荧光法（ＩＩＦＡ）。应用该ＩＩＦＡ方法对人工感染的ＳＰＦ鸡进行了检测１５只１日龄ＳＰＦ鸡在接种后第７、１４天时均呈阴性反应；２１天时２只鸡呈弱阳性反应，２８天时均呈弱阳性反应，２１天时２只鸡呈弱阳性反应，２８天时均呈弱阳性反应，３５天时呈明显阳性反应；１４只４０日龄ＳＰ     

5种消毒药对鸡传染性腔上囊病病毒的杀灭效果试验

用市售的腆类化合物、氯制剂、双季铵盐类化合物、酚类制剂和醛类制剂与鸡传染性腔上囊病病毒（ＩＢＤＶ）相混合,在４℃和３０℃作用２４ｈ,用１０００ＩＤ５０的剂量作用后的病毒液感染２３日龄健康ＡＡ鸡。感染后７２ｈ扑杀试验鸡,取期腔上囊,用ＩＢＤ－ＥＬＩＳＡ快速诊断盒检测ＩＢＤＶ抗原,仍呈阳性反应;用３ｍＬ／Ｌ的甲醛溶液与ＩＢＤＶ病毒液混合,在３７℃作用２４、３６和４８ｈ后,按以上剂量感染鸡,感染后７２ｈ扑杀,取其腔上囊,用ＩＢＤ－ＥＬＩＳＡ快速诊断盒 检测ＩＢＤＶ抗原,全部呈阴性。     

鸡贫血因子病全身免疫功能变化的研究

用鸡贫血病毒（ＣＡＶ）感染１日龄ＡＡ雏鸡,以未感染同龄ＡＡ雏鸡为对照,感染后不同时间检测其外周血液Ｔ、Ｂ细胞数量和ＩｇＧ,ＩｇＭ,ＩｇＡ含量,胸腺,法氏囊,脾脏ＩｇＧ,ＩｇＭ,ＩｇＡ抗体生成细胞和Ｔ细胞数量以及Ｔ、Ｂ细胞增殖功能;胸腺和脾脏白细胞介素２（ＩＬ－２）和干扰素（ＩＦＮ）诱生活性等的动态变化。     

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