中国流行株ＨＩＶ—1gag—gp120与ＩＬ／ＩＬ—６共表达核酸疫苗质粒的构建和

以pcDNA3.１( ）为载体，构建了中国流行株ＨＩＶ－1gag-gp1２０嵌合基因的核酸疫苗质粒；并以pIRES1neo为载体，构建了gap-gp120与ＩＬ－２／ＩＬ－６共表达的２种核酸疫苗质粒。将核酸疫苗质粒在体外转染ＢＨＫ－２１细胞，ＥＬＩＳＡ方法检测到３种核酸疫苗质粒均表达了目的ＨＩＶ－１结构蛋白。将核酸疫苗质粒免疫小鼠，免疫学指标检测结果表明，在本实验条件下，未能检测到含有gap-gp120的核酸疫苗质粒免疫鼠的细胞免疫和体液免疫功能的明显改变；而与ＩＬ－２／ＩＬ６共表达的２种核酸疫苗质粒使免疫鼠ＣＤ^ 4、ＣＤ^ 8T细胞数量明显升高，ＣonA和ＬＰＳ诱导的细胞增殖能力显著增强，ＣＴＬ活性明显提高，表明ＩＬ－２和ＩＬ－６有效地发挥了免疫佐剂作用。     

白细胞介素—3对猪瘟病毒E2基因疫苗免疫增强作用的研究

以昆明系小白鼠为试验动物，观察了白细胞介素－３（ＩＬ－３）对猪瘟病毒Ｅ２囊膜糖蛋白（ＨＣＶ Ｅ２）基因疫苗免疫效果的增强作用。用ＤＮＡ重组技术将ＨＣＶ Ｅ２基因和白小鼠ＩＬ－３基因克隆到ｐＩＲＥＳ１ｎｅｏ质粒，因在两者之间有脑心肌炎病毒（ＥＭＣＶ）的核糖体进入位点（ＩＲＥＳ）片段，可得到ＨＣＶ Ｅ２抗体效价。结果显示，ＩＬ－３能显著提高ＨＣＶ Ｅ２基因疫苗的免疫效果，表明ＩＬ－３可作为ＨＣＶ Ｅ２     

重组牛白细胞介素-2增强小鼠对伊氏锥虫可溶性抗原免疫应答的研究

使用伊氏锥虫可溶性抗原免疫小鼠，研究了同时注射重组牛白细胞介素－２（ｒＢＩＬ－２）对ＮＫ细胞杀伤活性及特异性抗体水平的影响。试验鼠随机分为４组：Ａｇ组，ｒＢＩＬ－２组，Ａｇ＋ｒＢＩＬ－２组和ＰＢＳ对照组。以ＬＤＨ释放法和间接ＥＬＩＳＡ法分别检测脾ＮＫ细胞杀伤活性及抗体水平。结果表明，首次免疫后２４ｄ，Ａｇ组ＮＫ细胞杀伤活性为３１．６％，ｒＢＩＬ－２组为９９．６６％，Ａｇ＋ｒＢＩＬ－２组为９８．９８％，对照组为１９．７３％；抗体效价Ａｇ组为２４，Ａｇ＋ｒＢＩＬ－２组为２６。说明ｒＢＩＬ－２可显著提高ＮＫ细胞杀伤活性及促进抗体生成，提高宿主免疫力。     

中药复方禽瘟王对机体免疫功能的影响

以ＢＡＬＢ／ｃ小鼠，京白蛋用鸡为对象，以白细胞介素－２（ＩＬ－２）干扰素（ＩＦＮ）和自然杀伤细胞（ＮＫＣ）为指标，观察了中药复方制剂禽瘟王对机体ＩＬ－２，ＩＦＮ，ＮＫＣ细胞的影响，结果表明，禽瘟王既能显著增强小鼠ＩＬ－２的活力，又能强化小鼠ＮＫＣ的杀伤活性，同时还可提高鸡体ＩＦＮ的效价水平，提示分充发挥ＩＬ－２，ＩＦＮ，ＮＫＣ网络的正向调节效应，可能是中药复方禽瘟王的药效学基础。     

斑点免疫金测定法检测鸡减蛋综合征抗体的研究

用胶体金标记提纯后的免抗鸡ＩｇＧ，建立了一件以微孔滤膜为固相载体，以红色胶体金作为标记物的检测ＥＤＳ－７６病毒抗体的斑点免疫金测定法（ＤＩＧＦＡ）．该法具有简便、灵敏、快速等优点，全过程于３～５分钟内完成，阳性结果在膜上呈现红色斑点；对鸡ＩｓＧ的最小检测量（灵敏度）为６３×１０－９ｇ；与其它病毒阳性血清无交叉反应。ＤＩＧＦＡ检测ＥＤＳ－７６抗体既可定性，也可定量。检测８０份待检血清，在ＨＩ检出的５６份阳性标本中（效价≥４ｌｏｇ２）用ＤＩＧＦＡ检出阳性标本５５份（效价≥６１ｏｇ２）二者阳性符合率为９８．２％．与ＨＩ比较，ＤＩＧＦＡ平均高２．５（ｌｏｇ２）。本技术为ＥＤＳ－７６和其它禽病的快速诊断和免疫监测提供了一个新的方法。     

肉用鸡垂体—肾上腺轴与免疫功能关系的研究

以艾维茵肉鸡为试验动物，研究了垂体－肾上腺轴在传染性腔上囊病病毒（ＩＢＤＶ）强毒株攻击时对免疫系统的调节作用。结果表明，用ＩＢＤＶ强毒株攻击后，试验鸡垂体－肾上腺轴活动加强，血清促肾上腺皮质激素（ＡＣＴＨ）和皮质酮（Ｆ）上升，抗ＩＢＤＶ抗体、白细胞介素２（ＩＬ－２）和白细胞介素３（ＩＬ－３）上升，Ｔ淋巴细胞转化率下降。未经ＩＢＤ疫苗免疫的鸡由于免疫系统遭到ＩＢＤＶ破坏，在ＩＢＤＶ强毒株攻毒后，抗Ｉ     

鸡T淋巴细胞IL－2的体外诱生及活性检测

经Ｌ１６（４５）正交试验选择，并经实验验证，鸡脾脏Ｔ淋巴细胞白细胞介素２（ＩＬ－２）体外诱生和活性检测的最优水平组合及适宜条件为２．５μｇ／ｍＬ伴刀豆蛋白Ａ（ＣｏｎＡ）、ＩＬ－２体外诱生时间２０ｈ、１×１０７／ｍＬ淋巴细胞、１０％小牛血清、靶细胞培养时间４８ｈ、４×１０６／ｍＬ靶细胞、靶细胞接触时间３６ｈ、５ｍｇ／ｍＬＭＴＴ、ＭＴＴ加入时间３ｈ和甲溶解时间２ｈ；胸腺Ｔ淋巴细胞ＩＬ－２体外诱生和活性检测的最优水平组合及适宜条件为５μｇ／ｍＬＣｏｎＡ、ＩＬ－２体外诱生时间４８ｈ，余同脾脏Ｔ淋巴细胞ＩＬ－２体外诱生及活性检测。比较试验表明，ＭＴＴ比色分析法和３Ｈ－胸腺嘧啶核苷（３Ｈ－ＴｄＲ）掺入法有显著的直线回归关系。     

产蛋下降综合征病毒单克隆抗体的制备

以粗提的ＥＤＳ－７６病毒（ＮＥ－４株）作为抗原，按常规方法免疫ＢＡＬＢ／ｃ鼠，最后一次免疫后第３天取脾细胞与ＳＰ２／０细胞进行融合，采用间接ＥＬＩＳＡ和ＨＩ进行双重筛选，共检出２５个阳性孔，阳性率为１４．８８％。对其中的１１个阳性值较高的孔进行３次克隆，最后获得的１１株杂交瘤细胞，经长期体外培养和冻存后复苏仍能稳定地分泌抗体；ＥＬＩＳＡ阻断试验和与其他病毒的交叉试验证明，其分泌的抗体具有高度特异性。经鉴定，１１株ＭｃＡｂ均为ＩｇＧ，均无免疫沉淀特性，腹水和细胞培养上清的ＥＬＩＳＡ效价分别为１：３２００～１：５１２００和１：１２８～１：２０４８。杂交瘤细胞的染色体数目为８０～１１２，平均９２。尤为重要的是，１１株杂交瘤细胞中有４株分泌抗ＥＤＳ－７６病毒血凝素决定簇的中和单抗，细胞培养上清和腹水的ＨＩ价分别为２１０～２￣（１２）和２￣（２２）～２￣（２４），腹水的中和效价为１：１２８０～１：５１２０。     

鸡新城疫V4弱毒疫苗免疫效果观察

选用Ｖ４弱毒疫苗免疫ＳＰＦ来航鸡，结果表明：接种该苗，１０天即产生免疫ＨＩ效价均值为５．０ｌｏｇ２，免疫后２０天达到免疫高峰ＨＩ效价均值为５．６ｌｏｇ２，免疫持续期为３４０天，此时，ＨＩ效价均值为５．０ｌｏｇ２。Ｖ４弱毒疫苗稍优于ｃｌｏｎ３－３０弱毒疫苗，但两者差异不显著。     

猪血清中天然LFA—3存在的探讨

测定了正常猪血清对ＳＲＢＣ的溶血作用。并根据猪血清对ＳＲＢＣ的破坏作用经ＳＲＢＣ吸收和加入ＳＲＢＣＬＦＡ－３后即显著降低或消夫，提出了猪血清破坏ＲＢＣ的作用与血清中游离ＣＤ２的存在有关的论断。此外，又根据反复解离和经ＳＲＢＣ吸收后的猪血清具有阻止正常猪血清对ＳＲＢＣ的破坏作用和猪ＰＢＭＣＥ玫瑰花环的形成，认为猪血清中可能存在天然的ＬＦＡ－３，进而对血清游离ＣＤ２在淋巴细胞激活中的功能提出了“游离”     

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.