传染性法氏囊病免疫保护试验中3种评定指标的比较

100只SPF鸡均分为5组，A、B、c3组免疫后攻毒，接种3批次自制的IBD基因工程重组亚单位油乳剂疫苗；D组不免疫不攻毒，E组不免疫而攻毒。免疫后第22天，感染IBDV强毒株BC-6／85。攻毒后第4天，将所有存活的鸡只以颈脱臼致死，收集法氏囊，以3种方法和指标（法氏囊眼观病变；法氏囊显微病变；法氏囊中IBDV抗原检测）进行分析，以评定免疫保护率。结果显示，以这3种方法和指标评定，A组免疫保护率为90％，B、C组免疫保护率均为95％；试验鸡A3、A14、B7、C16、E1～E20，法氏囊眼观病变明显，法氏囊显微病理损伤评分为3～5分，琼脂免疫扩散试验检测法氏囊中IBDV抗原均为阳性；其他试验鸡，法氏囊眼观无明显异常，法氏囊显微病理损伤评分在3分以下，琼脂免疫扩散试验检测法氏囊中IBDV抗原均为阴性。结果表明，这3种方法和指标在IBD疫苗免疫保护试验评定中具有很好的一致性。     

鸡传染性法氏囊病免疫复合物疫苗对1日龄低母源抗体水平雏鸡免疫效果的研究

将鸡传染性法代囊病病毒(IBDV)BX株抗原和IBDV高免血清按一定比例混合,初步制备了无菌的鸡传染性法氏囊病免疫复合物疫苗1~5(分别含有32、8、4、0.5及0.125单位IBDV中和抗体),用鸡传染性法氏囊病免疫复合物疫苗1~5及BX株活疫苗分别免疫1日龄低母源抗体水平雏鸡,免疫后9 d观察法氏囊病变,免疫后28 d采血测定IBDV中和抗体,并用强毒攻击,计算各组疫苗保护率。结果显示,免疫后9 d,复合物疫苗1~3免疫组鸡法氏囊正常,复合物疫苗4、5免疫组和BX株活疫苗免疫组分别有2/10、4/10和5/10的试验鸡法氏囊出现了病变;免疫后28 d,复合物疫苗1~5免疫组和BX株活疫苗免疫组IBDV中和抗体效价分别为8.34log2、9.60log2、9.21log2、7.88log2、9.50log2和9.12log2,攻毒保护率分别为90%、100%、100%、80%、90%和80%。试验结果表明鸡传染性法氏囊病免疫复合物疫苗2、3(分别含8、4单位IBDV中和抗体)免疫1日龄低母源抗体水平的雏鸡效果最好,攻毒保护率能达到100%。     

鸡传染性法氏囊病免疫复合物疫苗的安全性和免疫效力试验

用鸡法氏囊病免疫复合疫苗(IBDV-Icx)和常规IBD活疫苗分别免疫1日龄商品鸡和SPF鸡,进行疫苗的安全性及免疫效力比较.免疫后8d检测,IBDV-Icx免疫组鸡的法氏囊未见明显萎缩,而传统弱毒疫苗免疫组鸡的法氏囊萎缩明显;免疫后28d各组用IBDV标准强毒株进行攻击,IBDV-Icx免疫组鸡的攻毒保护率均为10/10,常规IBD活疫苗对照组分别为8/10及9/10.免疫后3个月,IBDV-Icx免疫组血清抗体可达AGP1∶32,攻击强毒仍为10/10保护,而常规IBD活疫苗免疫后2个月抗体AGP为0,攻毒保护率为1/10,免疫后3个月时攻毒10/10发病.     

鸡胚接种鸡白介素18重组质粒对IBDVDNA疫苗免疫增强作用的研究

用鸡白细胞介素18(ChIL-18)重组质粒(pCI-ChIL-18)接种18胚龄SPF鸡胚,利用适时荧光定量PCR方法对试验鸡不同时间点的动态变化进行检测.检测结果表明,胚胎接种pCI-ChIL-18使ChIL-18在鸡血液中早期持续高浓度存在,能促进鸡脾脏和法氏囊中ChIL-18基因的大量表达.用pCI-ChIL-18与传染性法氏囊病病毒(IBDV)多聚蛋白DNA疫苗分别免疫18胚龄SPF鸡胚,设1日龄雏鸡肌肉免疫对照组和空白对照组,2周龄时二免,6周龄时用IBDV标准强毒株BC6/85攻击.结果表明,胚胎免疫pCI-ChIL-18能显著促进试验鸡T、B淋巴细胞的早期增殖反应,增强IBDV多聚蛋白DNA疫苗诱导的早期抗体水平及其对强毒攻击的保护力.并进一步证明胚胎免疫pCI-ChIL-18对IBDV多聚蛋白DNA疫苗的早期免疫效果具有显著的增强作用(P相似文献   

鸡传染性法氏囊病免疫复合物疫苗对SPF雏鸡的免疫效果

用鸡传染性法氏囊病免疫复合物疫苗和活疫苗分别免疫1日龄SPF雏鸡,免疫后9d观察法氏囊病变,免疫后14、21、28d对各组鸡采血测定IBDV中和抗体,21d及28d时用强毒攻击,计算各组疫苗保护率。结果表明,免疫后9d免疫复合物疫苗组鸡法囊正常,活疫苗组鸡法氏囊全部明显萎缩;免疫后14、21、28d,免疫复合物疫苗组鸡IBDV中和抗体分别为2.9±0.99、8.1±0.88和10.6±1.78,活疫苗组IBDV中和抗体分别为3.3±1.14、8.3±1.16和9.2±1.23,免疫后21d及28d疫苗免疫组均100%保护。试验证明免疫复合物疫苗比活疫苗更为安全,免疫复合物疫苗免疫SPF雏鸡产生比活苗更高的IBDV中和抗体,保护率达100%。     

鸡传染性法氏囊病免疫复合物疫苗对1日龄中等母源抗体水平雏鸡免疫效果的研究

将鸡传染性法氏囊病免疫复合物疫苗和BX株活疫苗分别免疫1日龄中等母源抗体水平京红雏鸡,同时免疫1日龄SPF雏鸡作对照,免疫后第9天观察法氏囊病变,免疫后第28天采血测定IBDV中和抗体,并用强毒攻击,计算各组疫苗保护率。结果显示,免疫后第9天,免疫复合物疫苗组SPF雏鸡和京红雏鸡法氏囊均正常,BX株活疫苗组SPF雏鸡法氏囊出现了萎缩病变;免疫后第28天,对照SPF雏鸡和京红雏鸡的免疫复合物疫苗组、BX活疫苗组IBDV中和抗体效价分别为9.2log2、8.5log2和 7.2log2、4.4log2,攻毒保护率均为100%。试验结果表明免疫复合物疫苗免疫1日龄中等水平母源抗体雏鸡效果很好,能产生较高的中和抗体,攻毒保护率能达到100%。     

鸡传染性法氏囊病疫苗B87对SPF鸡289的免疫效果

30日龄SPF鸡经点鼻途径用鸡传染性法氏囊病病毒（1BDV）的中等毒力疫苗B87株免疫后14d，再以200个ELD50超强毒IBDV株GX8/99点鼻人工攻毒，所有鸡都没有发病死亡。而对照鸡有10/10发病和6/10死亡，并有典型的病理变化。这表明，对SPF鸡用中等毒力的IBDV疫苗免疫可诱发有效的免疫保护作用。并能完全抵抗超强毒IBDV的攻击。     

鸡新城疫-传染性支气管炎-传染性法氏囊病三联灭活疫苗安全性及效力试验

为评价以悬浮培养制备的鸡传染性法氏囊病毒(IBDV)抗原液为组份之一的鸡新城疫(ND)-传染性支气管炎(IB)-传染性法氏囊病(IBD)三联灭活疫苗的安全性及效力,实验室制备3批疫苗,按照《中国兽药典》附录对疫苗进行物理性状、无菌检验、安全及效力试验。结果显示3批次疫苗物理性状、无菌检验均合格;2倍剂量注射21日龄的SPF鸡,14 d后剖检注射部位未见炎症反应,疫苗吸收良好,说明疫苗安全;疫苗免疫SPF鸡后21 d,ND和IB血凝抑制(HI)抗体,IBD中和抗体均合格,攻毒实验证明,免疫鸡10/10保护,对照鸡5/5发病或死亡。表明以悬浮培养制备的IBDV抗原液生产的三联灭活疫苗安全有效。     

两株水貂阿留申全基因重组核酸疫苗的免疫效果初步评估

为评价以悬浮培养制备的鸡传染性法氏囊病毒(IBDV)抗原液为组份之一的鸡新城疫(ND)-传染性支气管炎(IB)-传染性法氏囊病(IBD)三联灭活疫苗的安全性及效力,实验室制备3批疫苗,按照《中国兽药典》附录对疫苗进行物理性状、无菌检验、安全及效力试验。结果显示3批次疫苗物理性状、无菌检验均合格;2倍剂量注射21日龄的SPF鸡,14 d后剖检注射部位未见炎症反应,疫苗吸收良好,说明疫苗安全;疫苗免疫SPF鸡后21 d,ND和IB血凝抑制(HI)抗体,IBD中和抗体均合格,攻毒实验证明,免疫鸡10/10保护,对照鸡5/5发病或死亡。表明以悬浮培养制备的IBDV抗原液生产的三联灭活疫苗安全有效。     

新型鸡传染性法氏囊病灭活疫苗(HQ株)对黄羽肉鸡免疫效果的观察

采用在DF1细胞上增殖的高滴度鸡传染性法氏囊病(IBD)病毒制备油乳剂灭活疫苗免疫黄羽肉鸡种鸡和雏鸡,以探讨IBD灭活疫苗(HQ株)对黄羽肉鸡的免疫效果。种鸡免疫试验结果显示:种母鸡体内产生高水平鸡传染性法氏囊病病毒(IBDV)血清中和抗体,免疫30 d后血清中和抗体均值可达18.5 log2,免疫150 d后血清中和抗体均值仍维持在16.0 log2;高水平的种鸡抗体能使子代获得高水平的母源抗体,使子代在出生后3周内能有效抵御IBDV强毒攻击。雏鸡免疫试验结果显示,无论是高母源抗体雏鸡或低母源抗体雏鸡均可在免后3周产生12.0 log2的中和抗体并持续上升,可在2个月内抵抗IBDV强毒的攻击。提示IBD灭活疫苗(HQ株)可用于出壳雏鸡的主动免疫。     

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