鸡源和鸭源EDS病毒的某些生物学特性比较

对 Ｅ Ｄ Ｓ 病毒鸡源株 （ Ｎ Ｅ４） 和鸭源株 （ Ｊ Ｅ１） 在繁殖动态、毒价、免疫原性、核酸酶切图谱、多肽组成等５ 个方面进行比较研究。结果表明, ２ 株相同血清型、不同宿主来源的 Ｅ Ｄ Ｓ 病毒在普通生物学特性方面基本相同, 但在核酸酶切图谱和多肽组成等分子生物学水平上存在明显差异。     

产蛋下降综合征（EDS－76）病毒DNA酶切图谱分析

选用ＥｃｏＲＩ、ＰｓｔⅠ、ＰｖｕⅡ、ＨｉｎｄⅢ、ＢｇｌⅠ和ＢｇｌⅡ６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种鸡源分离株与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ＰｓｔＩ－ＥｃｏＲＩ的双酶切也得到同样结果。鹅源分离株的酶切片段数分别为６、７、９、７、４和１０条，酶切图形和片段大小均与ＡＶ－１２７有很大不同，表明该分离株可能为１株血清型相同而基因组不同的ＥＤＳ－７６鹅腺病毒。     

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     

禽流感病毒核蛋白基因在重组杆状病毒中的表达

利用ＲＴ－ＰＣＲ方法成功地扩增了我国禽流感病毒分离株Ａ／Ｘｉｎｇｊｉａｎｇ／１／９６（Ｈ１４Ｎ５）的核蛋白（ＮＰ）基因,其限制性内切酶图谱和核苷酸序列与鸭源的标准Ｈ１４Ｎ５毒株几乎完全一致,与其它毒株则有较大差异,说明该鸡源分离株与鸭源毒株有非常近的亲缘关系。将ＮＰ基因定向克隆到杆状病毒转移载体ｐＶＬ１３９３中,再与杆状病毒线性ＤＮＡ（ＢＡＣ－Ｎ－ＢｌｕｅＤＮＡ）共转染于Ｓｆ９昆虫细胞中,经过三次蚀斑筛选,获得重组病毒ｒＢ２。用其细胞表达产物裂解后作ＳＤＳ－ＰＡＧＥ蛋白电泳、Ｗｅｓｔｅｒｎ－ｂｌｏｔ和ｄｏｔ－ＥＬＩＳＡ,结果表明ＮＰ基因在杆状病毒系统中获得了表达。同时用表达产物作琼脂扩散试验,结果表明表达产物与现行标准禽流感琼扩抗原具有相同的生物学活性。     

传染性法氏囊病病毒的生态学与流行病学研究

血清学调查结果表明,麻雀、鸭、鹅等均可自然感染传染性法氏囊病病毒（ＩＢＤＶ）,其血清阳性率分别为７．４％（４／５４）,９５．５％（３６３／３８０）和９．４％（１１／１１７）。从鸭和麻雀分离到的ＩＢＤＶ可适应于鸡胚和鸡胚成纤维细胞,并产生ＣＰＥ,对ＳＰＦ鸡有致病性。病毒核酸和结构蛋白的电泳分析结果表明,鸡源、鸭源和麻雀源ＩＢＤＶ均有２条核酸带,５条蛋白带,毒株间的病毒核酸及结构蛋白电泳迁移率无显著差异,但其结构蛋白的相对含量不尽一致。经鉴定,鸡源、鸭源和麻雀源ＩＢＤＶ均属血清Ⅰ型,为同源病毒。本研究结果提示,鸡并非是ＩＢＤＶ的唯一自然动物宿主,非鸡禽鸟类宿主的存在可引起ＩＢＤ的传播和续源流行,也为ＩＢＤＶ的变异提供了特殊的生态条件,成为诱导ＩＢＤＶ变异的另一重要因素。     

鸡新城疫和减蛋综合征异源二联灭活疫苗研究

将鸭源新城疫（ＮＤ）病毒Ｄ＿（１０）株和减蛋综合征（ＥＤＳ－７６）病毒ＧＣ＿２株于同一鸭胚同时增殖，用甲醛灭活后加入１０号白油制成ＮＤ和ＥＤＳ－７６异源二联灭活疫苗，简化了生产工艺，降低了成本，克服了鸡胚苗潜伏带毒的危险。经２０余万只鸡试用，表明该疫苗可有效预防ＮＤ和ＤＥＳ－７６。     

鸡产蛋下降综合症灭活疫苗研究──EDS_（76）—NE_（4）株病毒的培养与鉴

在对ＥＤＳ７６－ＮＥ４株病毒进行血清学鉴定之后，于鸭胚（ＤＥ）、鸭胚成纤维细胞（ＤＥＦ）、鸡胚（ＣＥ）、鸡胚成纤维细胞（ＣＥＦ）和鸡胚肝细胞（ＣＥＬ）上适应培养。结果表明，ＥＤＳ７６－ＮＥ４株病毒为鸡产蛋下降综合症病毒，该病毒能在ＤＥ、ＤＥＦ、ＣＥＬ上增殖，在ＤＥ上增殖，尿囊液的血凝价（ＨＡ）可达１∶２０４８０─１∶３２７６８０倍。     

鸡产蛋下降综合征病毒内蒙分离株的生物学特性研究

对鸡产蛋下降综合征病毒内蒙古地区分离株进行了生物学特性测定和血清学鉴定,结果表明,Ｂ４、Ｎ３株与１２７株均能抵抗乙醚、氯仿和胰蛋白酶,而在对酸、碱、温度及甲醛的稳定性测定中,Ｎ３株ＥＤＳ７６病毒对这些因素抵抗力强于Ｂ４株和１２７株,而Ｂ４株和１２７株ＥＤＳ７６病毒对这些因素的抵抗力基本相同,说明不同ＥＤＳ７６病毒株间理化特性上存在有差异。血清学试验结果表明,Ｂ４、Ｎ３株与１２７株ＥＤＳ７６病毒的血清学关系非常相近。     

鸡产蛋下降综合症灭活疫苗研究：EDS76—NE4株病毒的培养与鉴定

在对ＥＤＳ７６－ＮＥ４株病毒进行血清学鉴定之后，于鸭胚（ＤＥ）、鸭胚成纤维细胞（ＤＥＦ）、鸡胚成纤维细胞（ＣＥＦ）和鸡胚肝细胞（ＥＣＬ）上适应培养。结果表明，ＥＤＳ７６－ＮＥ４株病毒为鸡产蛋下降综合症病毒，该病毒能在ＤＥ、ＤＥＦ、ＣＥＬ上增殖，在ＤＥ上增殖，尿囊液的血凝价（ＨＡ）可达１：２０４８０－１：３２７６８０倍。     

PCR检测鸡减蛋综合征病毒

根据已报道的鸡减蛋综合征（ＥＤＳ－７６）病毒ＤＮＡ序列，设计合成了１对引物，建立了ＥＤＳ－７６病毒的双温式聚合酶链反应（ＰＣＲ）诊断方法。该方法对ＥＤＳ－７６病毒长春株、河南株和广东株扩增结果均为阳性；而对致死鸡胚孤儿病毒（ＣＥＬＯＶ）、鸡病毒性关节炎病毒（ＶＡＶ）、鸡传染性支气管炎病毒（ＩＢＶ）、鸡传染性法氏囊病病毒（ＩＢＤＶ）和鸡新城疫病毒（ＮＤＶ）的扩增结果均为阴性。可检测ＥＤＳ－７６病毒ＤＮＡ为０．３×１０－４ｐｇ。结果表明该方法特异且敏感。此外，将常规的三温式ＰＣＲ的操作规程改为双温式，反应体积由常规５０～１００μＬ改为２０μＬ，使其更加快速、简便、经济     

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.     

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     

Avian brood parasitism — a growing research area in behavioral ecology (part Ⅱ)

正We are pleased to publish the second special issue on avian brood parasitism and to be responsible guest editors for the two special issues of Chinese Birds (Vol. 3, No. 4, 2012 and Vol. 4, No. 1, 2013), entitled "Avian Brood Parasitism - A Growing Research Area in Behavioral Ecology". The first issue was published in December 2012. The goal of the two special issues is to publish accumulated knowledge and some of the recent developments in     

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

Tropical Animal Health and Production -