应用聚合酶链反应检测鉴别火鸡支原体方法的建立

根据基因库中火鸡支原体（ＭＭ）１６Ｓ ｒＲＮＡ基因序列（Ｇｅｎｅｂａｎｋ Ｕ０４６４９）,设计了一对跨幅为８５０ｂｐ的引物,用这对引物对４禽侏火鸡支原体标准菌株和６种其它禽病病原体进行ＰＣＲ扩增,结果４禽株鸡支原体菌株均得到片段大小与预期设计相一致的８５０ｂｐ的ＰＣＲ扩增产物,而其它６种禽病病原体（包括ＭＧ、ＭＳ和ＭＩ）的扩增结果则均为阴性,该ＰＣＲ能检出１００ｆｇ的火鸡支原体的ＤＮＡ模板。     

应用聚合酶链反应扩增鸡传染性喉气管炎病毒TK基因的研究

根据鸡传染性喉气管炎病毒（ＩＬＴＶ）ＴＫ基因的核苷酸序列设计并合成１对引物，用该引物对４株不同的的ＩＬＴＶ进行ＰＣＲ扩增。结果全部ＩＬＴＶ毒株均获得与试验设计相符的６４７ｂｐ的扩增片段，而对其它６种禽病原体的扩增结果均为阴性；敏感试验表明，该引物能检出１０ｐｇ的ＩＬＴＶ ＤＮＡ。     

采用二温式聚合酶链反应扩增鸡喉气管炎病毒TK基因的研究

建立了检测鸡喉气管炎病毒（ＩＬＴＶ）的二温式聚合酶链反应（二温式ＰＣＲ）,根据已报道的ＩＬＴＶ ＴＫ基因的序列,设计并合成了１对引物,用二温式ＰＣＲ对５株不同ＩＬＴＶ ＤＮＡ进行扩增。该对引物对５株ＩＬＴＶ ＤＮＡ均扩增出与预期大小相一致的６４７ｂｐ的扩增产物,而对新城疫病毒（ＮＤＶ）、传染性支气管炎病毒（ＩＢＶ）、禽呼肠孤病毒（ＡＲＶ）、禽沙门氏菌、鸡毒霉形体和禽巴氏杆菌等６种禽病病原体的扩增,     

应用多重聚合酶链反应同时检测鉴别鸡新需疫病毒,鸡传染性支气管炎病毒,鸡

本文建立了一种同时检测ＤＮＶ、ＩＢＶ、和ＭＧ４种病原体的多重ＰＣＲ技术。根据ＮＤＶ、ＩＢＶ、ＩＬＴＶ和ＭＧ的基因文库,设计了４对分别与ＮＤＶ、ＩＢＶ、ＩＬＴＶ和ＭＧ某段基因序列互补的引物,用这４对引物对同一样品中的ＮＤＶ、ＩＢＶ、ＩＬＴＶ、ＭＧＲＶＡ和ＤＮＡ模板进行多重ＰＣＲ扩增,结果均同时得到了４条特异性大小与实验设计相符的３１０ｂｐ（ＮＤＶ）、１７２０ｂｐ（ＩＢＶ）、６４７ｂｐ（ＩＬＴＶ）和７３２ｂｐ（ＭＧ）多重ＰＣＲ扩增带,而对其他６种禽病病原的ＰＣＲ扩增结果均为阴性;敏感性测定结果表明,该多重ＰＣＲ技术难检出１０ｐｇ的ＩＢＶ、１ｂｇ的ＮＤＶ ＲＮＡ模板和ＩＬＴＶ、１ｐｇ的ＭＧ ＤＮＡ模板。     

应用多重反转录—聚合酶链反应检测鸡新城疫病毒和传染？…

本文建立了一种同时检测ＮＤＶ和ＩＢＶ二种病原体的多重ＰＣＲ。根据ＮＤＶ和ＩＢＶ的基因文库，设计了两对分别与ＮＤＶ与ＩＢＶ某段基因序列互补的引物，用这两对引物对同一样品ＮＤＶ和ＩＢＶＲＮＡ模板进行多重ＲＴ－ＣＰＲ扩增，结果均得到了两条特异性大步与实验设计相符的３１０ｂｐ和１７２０ｂｐ多重的ＲＴ－ＣＰＲ扩增带，而对其他６种禽病病原的ＰＣＲ扩增结果均为阴性，敏感性测定结果表明，该多重ＲＴ－ＰＣＲ技术能同     

用反转录聚合酶链反应检测禽呼肠孤病毒的研究

本文报告了建立反转录聚合酶链反应（ Ｒ Ｔ Ｐ Ｃ Ｒ）检测禽呼肠孤病毒（ Ａ Ｒ Ｖ）的方法,根据禽呼肠孤病毒 Ｓ１１３３ 毒株 Ｓ１ 基因序列,设计合成两对引物,用 Ｒ Ｔ Ｐ Ｃ Ｒ 技术对 ６ 株禽呼肠孤病毒国际标准株进进行了检测。结果两对引物对 ６ 株 Ａ Ｒ Ｖ 均可扩增出与预期大小相符 ５３２ｂｐ 和 ４３５ｂｐ 的 Ｒ Ｔ Ｐ Ｃ Ｒ 产物,而对其它 ６ 种禽病病原核酸的扩增结果均为阴性;该 Ｒ Ｔ Ｐ Ｃ Ｒ 可以检测出 １ｐｇ 的 Ａ Ｒ Ｖ Ｒ Ｎ Ａ 模板。     

RT-PCR检测禽传染性支气管炎病毒

用２对已发表的引物和１对自行设计的引物对同一禽传染性支气管炎病毒（ＩＢＶ）Ｈ１２０株进行ＲＴ－ＰＣＲ,分别获得了Ｓ１基因上与引物设计相一致的１７２０、２２８、６０２ｂｐ的扩增片段。用自行设计的引物对７个毒株（Ｈ１２０、Ｈ５２、Ｍ４１、Ｃｏｎｎ、Ｇｒａｙ、Ｔ、Ｈｏｌｔｅ）和５个分离株（宜毒、上毒、云毒、ＨＫ、１１８）的含毒尿囊液或纯化病毒进行ＲＴ－ＰＣＲ,结果除Ｈｏｌｔｅ株和２个分离株（宜毒、云毒）外,其余均成功地扩增出６００ｂｐ的片段。用１．７、０．２、０．６ｋｂ３对引物对６个ＩＢＶ毒株和６个分离株的含毒尿囊液在相同和不同条件下进行ＲＴ－ＰＣＲ,结果３对引物分别扩增出３、５、９株ＩＢＶ,同时可将不同血清型的１２个ＩＢＶ株分成６种基因型。将ＩＢＶ分离株ＨＫ与标准株Ｍ４１经ＰＣＲ扩增、ＨａｅⅢ和Ｈｉｎｄ酶切、ＲＦＬＰ分析,表明属同一马萨诸塞血清型。３株ＩＢＶ（Ｈ１２０,ＨＫ,Ｍ４１）在鸡胚中繁殖,ＰＣＲ最早检出的时间为２０～２４ｈ。ＲＴ－ＰＣＲ提供了直接从尿囊液和感染鸡组织中快速检测病毒的新方法。     

应用PCR技术检测沙门氏菌

参照文献报道的根据沙门氏菌组氨酸转运操纵子基因片段所设计的引物序列,合成了１对长２５ｂｐ的引物,对沙门氏菌属Ａ－Ｆ各群中共１６株沙门氏标准菌株和其他１２株非沙门氏菌标准菌株进行ＤＮＡ抽提扩增、结果沙门氏菌ＰＣＲ产物都出现４９５ｂｐ的特异性ＤＮＡ扩增带,而非沙门氏菌均未出现扩增条带,证明这对引物具有沙门氏菌属特异性。     

应用多重聚合酶链式反应检测鸡毒支原体、鸡滑液囊支原体和禽衣阿 …

根据鸡毒支原体（ＭＧ）、禽衣阿华支原体（ＭＩ）、鸡滑液囊支原体（ＭＳ）的基因文库,设计了３对分别与ＭＧ、ＭＩ、ＭＳ某段基因序列互补的引物。用这３对引物对同一样品种的ＭＧ、ＭＩ、ＭＳ ＤＮＡ模板进行多重聚合酶链式反应（ＰＣＲ）扩增,结果均同时得到了３条特异性的大小与实验设计相     

用聚合酶锭反应检测鸭瘟病毒的研究

根据已发表的鸭瘟病毒基因序列，设计并合成了一对引物，其扩增跨幅为６０２ｂｐ。用这对引物对６株鸭瘟病毒ＤＮＡ进行扩增，均获得了与设计大小相符的明亮条带，为阳性率人而对其它６株禽病的原体基因扩增不出任何条带，为阴性。敏感试验表明可检测到１００ｆｇ的鸭瘟病毒ＮＤＡ模板。     

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.     

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     

Evaluation of the Microbiological Status of Milk and Various Structures in Mammary Glands from Naturally Infected Dairy Cows

A knowledge of the microbiological status of milk and of the different structures in the mammary glands has great importance in elucidating the pathogenesis of mammary gland infections. The objective of this study was to evaluate the microbiological status of various structures in the mammary glands from naturally infected dairy cows following slaughter. A total of 94 samples of milk, 184 samples of mammary parenchyma, 168 samples of gland cisterns, and 168 samples of teat cisterns were collected for microbiological examination. Microorganisms were detected in 59.9% of all samples, 67.0% of the milk samples, 70.1% of the mammary parenchymas, 55.9% of the gland cisterns and 48.8% of the teat cistern samples. When all samples were considered, coagulase-negative Staphylococcus were the most prevalent (35.7%) followed by coagulase-positive Staphylococcus (12.2%), Corynebacterium bovis (2.4%), Prototheca sp. (1.9%), and Streptococcus dysgalactiae (1.5%). There was a significantly higher occurrence of microorganisms in the milk and mammary parenchyma compared to the gland cisterns and teat cisterns. This revised version was published online in July 2006 with corrections to the Cover Date.     

Development and survival of free-living stages of gastrointestinal nematodes of sheep and goats on pasture in the Nigerian derived savanna

Four grass plots were sequentially contaminated with goat faeces containing known numbers of unembryonated eggs of predominantly Haemonchus contortus and Trichostrongylus spp. between October 1982 and April 1983. Four other plots were similarly contaminated with sheep faeces between February and May 1987. An additional plot was repeatedly contaminated with sheep faeces from February to April 1987. Populations of free-living stages in faeces and of infective larvae (L₃) in the herbage were subsequently monitored until the end of April and June of 1983 and 1987 respectively. During February and May 1987 two control cultures of sheep faeces were incubated in the laboratory at 25°C–30°C and at a constant temperature of 50°C and the free-living development was also monitored. L₃ developed very readily in the faeces cultured at 25°C–30°C and in those spread on a grass plot in October, at the end of the wet season, but developed less on the plot contaminated in May at the start of the wet season. Worm eggs in faeces deposited on plots during the hot dry season (December to April) or incubated at 50°C died and disintegrated after 24–48 h exposure to the high environmental temperatures. The results indicate that it is unlikely that gastrointestinal nematodes of sheep and goats can develop or survive on open pasture during the dry season in the Nigerian derived savanna zone.