产蛋下降综合征（EDS—76）病毒DNA酶切图谱分析

选Ｅｃｏ，Ｒｉ，Ｐｓｔ，Ｉ，Ｐｖｕ ＩＩＩ，ＨｉｎｄＩＩＩ，Ｂｇ１Ｉｔ和Ｂｇ１ＩＩＩ６种限制性内切酶，对国内４株ＥＤＳ－７６病毒鸡源分离株和国外标准株ＡＶ－１２７及１株鹅源腺病毒的ＤＮＡ进行酶切图谱的比较，结果发现４种鸡源分离株子ＡＶ－１２７株用上述６种酶切的片段数分别为４，８，１０，１０，６和７条。各酶切图形，片段大小亦十分相似，表明均为ＥＤＳ－７６病毒。ＥｃｏＲＩ－ＨｉｎｄⅢ和Ｐｓｔ－Ｉ－Ｅｃ     

鸭源和鸡源减蛋综合征病毒（EDSV）酶切图谱的分析

选用限制性内切酶ＨｉｎｄⅢ、ＥｃｏＲＩ、ＢａｍＨＩ和ＢｇｌⅠ进行鸭源减蛋综合征（ＥＤＳ）病毒（ＪＥ１株）和鸡源ＥＤＳ病毒（ＮＥ４株）的酶切图谱分析，发现鸭源ＥＤＳ病毒的这些酶切片段分别为９，４，４，６条，而鸡源ＥＤＳ病毒（ＮＥ４株）则为１０，４，４，５条，两者的酶切图形和片段大小有些不同，说明ＥＤＳ病毒宿主不同，即使血清型相同，基因型也有差异。     

3株减蛋综合征病毒毒株核酸酶切谱分析

选用ＥｃｏＲⅠ、ＢａｍＨⅠ、ＨｉｎｄⅢ、ＥｃｏＲⅤ、ＰｖｕⅡ、ＢｇｌⅠ、ＳｍａⅠ和ＰｓｔⅠ等８种限制性内切酶,对不同地区分离的３株减蛋综合征（ＥＤＳ）病毒进行酶切图谱比较。结果发现３株毒用前６种酶切割后产生的片段数及各片段的大小均相同,而用ＳｍａⅠ和ＰｓｔⅠ切割后,贵州分离毒ＨＳ－１与国际标准毒ＡＶ－１２７、南京他离毒ＧＣ２相比,多出１个片段。表明不同地区ＥＤＳ分离毒的核酸结构基本相同而又略有差异     

用Digoxigenin标记核酸探针检测EDS—76病毒核酸的研究

用ＥＤＳ－７６病毒标准ＡＶ１２７株和分离株感染鸭胚,提取病毒核酸,分别经ＥｃｏＲ１和Ｐｓｔ１双酶切,获得图形和大小相似的酶切片段。分别进行了ＥｃｏＲｌ和Ｐｓｔｌ单酶切,也得到相似结果。病毒ＤＮＡ经ＥｃｏＲｌ和Ｐｓｔｌ双酶切后,与ＰＵＣ１９质粒载体重组,并转化到ＥｃｌｉＪＭ１０１中,筛选出一个插入片段约为２．７ｋｂ的重组质粒。     

减蛋综合征病毒基因组DNA的酶切分析

采用差速离心法化了鸭胚尿囊液中的减蛋综合征（ＥＤＳ－７６）病毒ＷＰＤＶ２０５株并提取了病毒基因组核酸。选用ＥｃｏＲＩ和ＢａｍＨＩ两种限制性内切酶分别对病毒基因组ＤＮＡ刊物单酶切和双酶切处理，单酶切消化均产生４个片段、双酶切消化产生７个惩段。用琼脂糖凝胶电泳方法测定了病毒基因组ＤＮＡ和所有酶切片段的分子质量，将这些结果与ＡＶ－１２７标准株和Ｂ８－７８株基因组ＤＮＡ由相贩内切酶消化的结果进行比较，发现     

用 Digoxigenin 标记核酸探针检测 EDS-76 病毒核酸的研究

用ＥＤＳ７６病毒标准ＡＶ１２７株和分离株（Ｂ９６株）感染鸭胚,提取病毒核酸,分别经ＥｃｏＲｌ和Ｐｓｔｌ双酶切,获得图形和大小相似的酶切片段。分别进行ＥｃｏＲｌ和Ｐｓｔｌ单酶切,也得到相似结果。病毒ＤＮＡ经ＥｃｏＲｌ和Ｐｓｔｌ双酶切后,与ＰＵＣ１９质粒载体重组,并转化到ＥｃｏｌｉＪＭ１０１中,筛选出一个插入片段（Ｇ片段）约为２７ｋｂ的重组质粒。用Ｄｉｇｏｘｉｇｅｍｉｎ标记ＥＤＳ７６ＤＮＡＧ片段（ＥｃｏＲｌ和Ｐｓｔｌ双酶切片段）及含该片段的重组质粒分别制备探针,对ＥＤＳ７６病毒ＤＮＡ进行斑点杂交,两种探针均为阳性,而对照组ＮＤＶ、ＩＢＶ、ＩＬＴＶ、ＩＢＤＶ正常鸭胚尿囊液的核酸为阴性。且后一种探针的敏感性高于前者,它的ＤＮＡ检出限量为４ｐｇ水平。结果表明,两种探针具有高度的特异性、敏感性。     

牛传染性鼻气管炎病毒tk基因的克隆

根据牛传染性鼻气管炎病毒ＬＡ株的物理图谱及Ｃｏｐｅｒ株和ＬＡ标ｔｋ基因在基因组中的定位，将ＬＡ株ＤＮＡ ＨｉｎｄⅢＡ片段中的ＳａｌＩ－ＳａｌＩ亚片段、ＢｇｌⅢ－ＳａｌＩ双酶切亚片段分别克隆到载体质粒ｐＢｌｕｅｓｃｒｉｐｔＳＫ中，筛选出３个重组质粒ｐ＾ｔｋ－１，Ｐｔｋ－２和Ｐｔｋ－３，其外源片段大小分别为２．７ｋｂ，１．１ｋｂ和１．６ｋｂ。经酶切分析及同源核酸探针杂交试验表明，２．７ｋｂ ＳａｌＩ－     

减蛋综合征病毒全基因组DNA文库的构建及物理图谱分析

Ｅ Ｄ Ｓ Ｖ Ａ Ａ２ 株纯化 Ｄ Ｎ Ａ 经 Ｈｉｎｄ Ⅲ、 ＰｓｔⅠ和 Ｓｐｈ Ⅰ水解后, 分别提取 Ｄ Ｎ Ａ 片段并克隆至ｐ Ｂｌｕｅｓｃｒｉｐｔ Ｋ Ｓ（ ＋ ） 和ｐ Ｇ Ｅ Ｍ３ Ｚｆ （ ＋ ） 载体, 构建了 Ｅ Ｄ Ｓ Ｖ 全基因文库。根据 Ｅ Ｄ Ｓ Ｖ Ｄ Ｎ Ａ 片段和基因组 Ｄ Ｎ Ａ 电泳迁移率计算, Ｅ Ｄ Ｓ Ｖ 基因组大小为３２９ｋｂ , 通过克隆片段酶谱鉴定, 杂交建立了 Ｅ Ｄ Ｓ Ｖ 限制性内切酶 Ｈｉｎｄ Ⅲ、 Ｐｓｔ Ⅰ和 Ｓｐｈ Ⅰ的物理图谱。     

鸡产蛋下降综合征病毒NE4株DNA的EcoRI＋BamHI部分酶切片段的克隆

用ＳＤＳ－蛋白酶Ｋ消化ＥＤＳＶ抗原－抗体复合物、酚－氯仿抽提ＤＮＡ,得到了完整的ＥＤＳＶ基因组ＤＮＡ（约３３ｋｂ）,用限制性内切酶ＥｃｏＲＩ＋ＢａｍＨＩ双酶切,得到７个片段,分别回收各片段,与双酶切线性化的ＰＵＣ１９载体质粒连接,转化Ｅ．ｃｏｌｉＤＨ５α,成功地克隆了其中的５个片段。     

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。     

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