用放射免疫沉淀试验比较不同IBDV毒株的中和表位

用单克隆抗体（ＭＡｂ）对传染性法氏囊病病毒（ＩＢＤＶ）不同毒株中和表位的相关性进行了分析。ＭＡｂ Ｂ６９能中和同源病毒Ｄ７８株，但不中和ＭＤ及ＩＢＤＶ Ｄｅｌ－Ａ变异株。而ＭＡｂ ３３Ｅ８和Ｒ６３能中和Ｄ７８株和ＭＤ及Ｄｅｌ－Ａ变异株。在体外将Ｄｃｌ－Ａ株ＶＰ２基因和一个１０＾３ｂｐ片段的ｃＤＮＡ克隆进行翻译，得到６种多肽，它们代表了一个全长产物（３５．５ｋｄ）和５份切割片段。用ＭＡｂ Ｂ６９、３     

鸡传染性法氏囊病毒血清Ⅰ型和亚型混合弱毒疫苗研究初报

由美国ＩＢＤ血清Ⅰ型商品弱毒疫苗Ｂｕｒｓａ－Ｖａｃ，Ｕｎｉｖａｘ ＢＤ和中国广东的亚型弱毒疫苗ＣＮ９０３，ＣＳ９０４混合组成的弱毒疫苗，免疫剂量为１０００ＴＣＩＤ５０，对１２日龄无ＩＢＤ血清中和抗体或≤１：８的试验鸡，免疫试验结果表明，免疫后７天，能够产生９０－１００％的保护作用。ＩＢＤ混和弱毒疫苗保存在３４－３７℃１周，４－１０℃４周和－２５℃１２个月，疫苗的免疫保护率仍达１００％。对５个品种的     

犬瘟热疫苗弱毒的复壮与免疫试验

将一株犬瘟热疫苗株病毒通过Ｖｅｒｏ细胞２０代（ＣＤＶ／Ｒ－２０）后又通过敏感犬的腹腔巨噬细胞，获得一株免疫原性更高的弱毒株（ＣＤＶ／Ｒ－２０／８）。接种同样剂量１０４ＴＣＩＤ５０的ＣＤＶ／Ｒ－２０／８和ＣＤＶ／Ｒ－２０的犬，产生出血清中和（ＳＮ）抗体价的几何平均数分别为１：５４和１：２６。前者为后者的２倍多。接种１０５ＴＣＩＤ５０的ＣＤＶ／Ｒ－２０／８能完全保护犬（１０／１０）抵抗ＣＤＶ强毒的攻击，接种１０４ＴＣＩＤ５０的保护９／１０犬，而对照犬５只全部发病，其中４只死亡。犬体内ＳＮ价可持续一年之久。冻干培养物在４和－３０℃中可分别保存９个月和１２个月而效力不减。     

分泌抗禽呼肠孤病毒单克隆抗体杂交瘤细胞株的建立与鉴定

采用腹腔的接种１次脾内注射禽呼肠孤病毒（ＡＲＶ）蛋白免疫小鼠，经３次融合后，共筛选８株分泌抗禽呼肠孤病毒（单克隆抗体杂交瘤细胞株，这８株ＭｃＡｂ均可与ＡＲＶＳ１１３３株，ＦＤＯ株发生反应，而与ＩＢＤＶ，ＭＤＶ，ＥＤＳ－７６病毒不发生反应，经亚类鉴定，ＡＥ７，ＡＦ８，ＢＤ１，ＤＨ１０，ＥＥ５为ＩｇＧ１；ＡＤ６，ＣＧ４为ＩｇＣ２ａ，ＡＧ７为ＩｇＧ２ｂ。腹水效价在１０＾３～１０＾５之间。     

用单克隆抗体鉴定猪繁殖与呼吸综合征病毒分离株

应用ＰＲＲＳＶ单克隆抗体,采用直接与间接免疫荧光抗体试验对分离获得的ＰＲＲＳＶ６个毒株进行了鉴定,结果所有分离毒株均能被单克隆抗体（ＳＤＯＷ１７、Ａ、Ｂ、Ｃ、Ｄ、Ｅ、Ｆ）所识别,呈现特异荧光,６个分离毒株均能与仅识别美洲型ＰＲＲＳＶ的单克隆抗体Ｆ反应,结果表明６个分离毒株均属于美洲型ＰＲＲＳＶ。利用微量细胞培养对分离毒株ＴＣＩＤ５０测定结果表明,６个分离毒株的ＴＣＩＤ５０分别为１０－７．５／０．１ｍｌ、１０－７．５／０．１ｍｌ、１０－７．５／０．１ｍｌ、１０－７．７５／０．１ｍｌ、１０－７．２５／０．１ｍｌ、１０－６．２５／０．１ｍｌ。病毒感染细胞的超薄切片电镜观察表明,在感染细胞浆内可见典型的ＰＲＲＳＶ病毒粒子,呈球形或椭圆形,直径约为６０ｎｍ左右,可见囊膜。     

禽用生物制品外源病原监测研究：鸡新城疫LaSota活苗中污染IBV的检测研究

使用ＳＰＦ鸡制备的抗ＮＤＶ（新城疫病毒）高免血清可中和ＮＤＶ种毒或鸡新城疫疫苗ＬａＳｏｔａ株１０~７ＥＩＤ５０／０．１ｍｌ（即１０个使用剂量），并具有高度持异性。对于ＮＤＶ疫苗实验室模拟污染ＩＢＶ传染性支气管炎病毒）研究表明，用ＮＤＶ高免血清中和ＮＤＶ疫苗１０个使用剂量后，可检测到ＩＢＶ１０~（－６）污染水平。对于某生药厂ＮＤＶＬａＳｏｔａ疫苗中疑似ＩＢＶ污染的样品进行检测，排除了ＩＢＶ污染。文章同时证明了免疫胚接种ＮＤＶＬａＳｏｔａ毒后胎儿表现出类似感染了ＩＢＶ的病变。     

单抗介导的斑点ELISA检测鸡传染性支气管炎病毒的研究

用群特异性的单克隆抗体作第一抗体,用酶标兔抗体ＩＢＶＩｇＧ作第二抗体,建立夹心法Ｄｏｔ－ＥＬＩＳＡ程序检测鸡传染性支气管炎病毒抗原。试验表明,本程序检测ＩＢＶ抗原高度敏感性和特异性。最低抗原检出量为０．５μｇ,约１００个气管环半数感染量（１００ＴＯＣＩＤ５０）,阳性检出率为９６％。     

抗小鹅瘟病毒中和性单克隆抗体研制及实验防治效果

用淋巴细胞杂交瘤技术研制出１１株抗小鹅瘟病毒（ＧＰＶ）单克隆抗体。这些单抗仅与ＧＰＶ反应，与其它细小病毒（ＣＰＶ、ＦＰＶ、ＰＰＶ）和其它禽病毒（ＮＤＶ、ＩＢＤＶ、ＤＨＶ、ＤＰＶ）均不反应。腹水单抗的ＥＬＩＳＡ效价达１０－５—１０－７，琼扩沉淀效价达１∶２０—１∶５１２，鹅胚中和效价达１∶３０—１∶１２２，鹅体中和效价为１∶５４—１∶９６。ＧＰＡ１和ＧＰＣ５２株单抗对人工感染ＧＰＶ的雏鹅具有良好防治效果。     

抗小鹅瘟病毒中和性单克隆抗体的研制及实验防治效果

用淋巴细胞杂交瘤技术研制出１１株抗小鹅瘟病毒（ＧＰＶ）单克隆抗体。这些单抗仅与ＧＰＶ反应，与其它细小病毒（ＣＰＶ、ＦＰＶ、ＰＰＶ）和禽病毒（ＮＤＶ、ＩＢＤＶ、ＤＨＶ、ＤＰＶ）均不反应。腹水单抗的ＥＬＩＳＡ效价达１０－５～１０－７，琼扩沉淀效价达１２０～１５１２，鹅胚中和效价达１３０～１１２２，鹅体中和效价为１５４～１９６。ＧＰＡ１和ＧＰＣ５两株单抗对人工感染ＧＰＶ的雏鹅具有良好防治效果。     

乙型脑炎病毒HW1克隆纯化株的鉴定及外源性污染的鉴定

应用病毒蚀斑技术，将乙型脑炎病毒ＨＷ１株在鸡胚成纤维细胞（ＣＥＦ）单层培养上连续挑斑纯化３次，对纯化后的克隆株进行血清学，免疫生物学鉴定及外源性污染检定。毒株对ＢＨＤ－２１细胞感染滴度≥１０＾６．１５ＴＣＩＤ５０；对８－９ｇ小鼠脑内感染的毒力≥１０＾７．１０ＬＤ５０／０．０４ｍＬ；与ＪＥＶＰ３株阳性参考血清的中和指数≥２０００；克隆株对猪有较好的的性，无外源性污染。     

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