应用LHD-Sj23和SjCL基因重组抗原诊断水牛日本血吸虫病的研究

目的：验证日本血吸虫基因重组抗原检测水牛日本血吸虫病的效果。方法：以日本血吸虫基因重组抗原LHD-Sj23／pGEX和SjCL／pET-28a( )作为抗原，应用ELISA法检测水牛日本血吸虫病。结果：感染日本血吸虫病阳性符合率分别为93．3％(42／45)和95．6％(43／45)，阴性符合率分别为93．3％(42／45)和80％(36／45)。和以血吸虫成虫抗原(SWAP)和虫卵(SEA)抗原作为诊断抗原获得的结果差异不明显。同时将上述两种基因重组抗原混合作为诊断抗原，检测水牛血吸虫病，结果阳性符合率为88．9％(40／45)，阴性符合率为33．3％(15／45)。结论：由于基因重组抗原制备简便、价廉，有利于诊断技术的标准化。因此，基因重组抗原在血吸虫病诊断领域有着良好的研究和应用前景。     

三种抗原对家畜日本血吸虫病诊断价值的比较

以日本血吸虫基因重组抗原LHD-Sj23／pGEX、可溶性虫卵抗原（soluble egg antigen，SEA）及SEA经Sephadex G-200柱层析分离后得到的第一峰SEAl作为诊断抗原，应用ELISA检测人工感染日本血吸虫绵羊血清及自然感染日本血吸虫水牛血清。结果显示，三种抗原用于检测人工感染日本血吸虫绵羊血清的阳性符合率分剐为88．79％、98．15％、100％，阴性符合率均为100％；自然感染日本血吸虫水牛血清的阳性符合率分别为80％、80％、84％，阴性符合率分别为88．9％、93．3％、91．1％；三种抗原与伊氏锥虫病牛血清无交叉反应；检测感染日本血吸虫不同时间绵羊血清，发现感染6周后均被检出针对这三种抗原的特异性抗体，且SEA及SEAl在感染4周后即可检出特异性抗体。三种抗原的诊断效果差异不显著。     

应用重组日本血吸虫组织蛋白酶L诊断日本血吸虫病的研究

在大肠杆菌BL21中表达日本血吸虫组织蛋白酶L基因，经镍离子亲和层析柱纯化得到重组日本血吸虫组织蛋白酶L；以间接ELISA法，检测血吸虫病因牛血清104份，阳性检出率为67．31％；以血吸虫感染小鼠、兔、绵羊血清做阻断试验，得到的OD值与阴性血清相当。结果表明，以重组日本血吸虫组织蛋白酶L作为诊断抗原检测日本血吸虫病牛感染情况，有一定的应用前景。     

日本血吸虫Sj32KD抗原基因的克隆、表达及诊断应用

目的开展日本血吸虫中国大陆株Sj32KD抗原基因研究,探讨其作为诊断抗原的潜力。方法应用PCR方法克隆Sj32KD抗原基因,并在大肠杆菌系统中进行表达,利用H is亲和层析方法纯化融合蛋白,并应用重组的Sj32KD抗原检测羊日本血吸虫病。结果克隆了ORF为1 272bP的日本血吸虫中国大陆株Sj32KD抗原基因,成功构建表达质粒Sj32-pET28 a,并在BL21(DE3)菌株中获得了分子量为47KD的特异性表达产物。应用Sj32KD重组抗原应用于检测羊日本血吸虫病,结果阴性血清的特异性为85.71%,阳性血清的敏感性为95.45%。结论成功克隆表达了日本血吸虫Sj32KD抗原,原核表达融合蛋白有一定的诊断应用潜力。     

检测家畜血吸虫抗体的二步金标免疫渗滤法研究

将待检家畜血纸浸出液点在硝酸纤维素膜上，以金标记的血吸虫虫卵可溶性抗原为探针（以下简称血吸虫抗原胶体金），建立了检测家畜血吸虫抗体的二步金标免疫渗滤法（Two-step Dot Immunogold Filtration Assay，T—DIGFA）。家畜血吸虫病阳性血样在50-90S形成肉眼可观察的红色斑点，可进行快速诊断。该法可以检测出人工感染血吸虫尾蚴7d和7d以上的阳性牛和兔血纸抗体，与肝片吸虫、锥虫、蛔虫病之间无交叉反应。T—DIGFA检测粪孵血吸虫毛蚴阳性牛血纸139份、阴性牛血纸130份，与粪孵法阳性符合率为100％，阴性符合率为99．2％；T—DIGFA与斑点酶联SPA法阳性符合率和阴性符合率完全相同。血吸虫抗原胶体金在4～8℃保存期可达6个月、室温保存期为3个月。试验证实，T-DIGFA有很高的敏感性、特异性、重复性和稳定性，适合于基层单位和现场进行家畜血吸虫病抗体的快速诊断、普查和检疫。     

犬瘟热琼脂扩散试验方法的建立及初步应用

采用犬瘟热鸡胚成纤维细胞弱毒疫苗免疫绵羊制备琼脂扩散抗体，应用犬瘟热病貉肝脏（电镜检查“＋＋”以上）制备琼脂扩散抗原，建立了琼脂扩散试验方法，用于犬瘟热病死动物肝、脾脏器中病毒抗原成分的检出。检测送检病料１０份，与电镜检查结果比较，阳性符合率为８５．７％（６／７），阴性符合率为７５％（３／４），总体符合率为９０％（９／１０）。本方法特异、敏感，操作简便，易于推广应用。     

用弓形虫代谢分泌抗原制备间接血凝诊断试剂的研究

用弓形虫代谢分泌抗原(E／SA)致敏绵羊红细胞制备间接血凝诊断试剂，进行人和动物弓形虫病血清抗体检测，并用弓形虫虫体抗原致敏的红细胞间接血凝诊断试剂进行对照试验。结果表明，在弓形虫阴性、阳性血清检测中，弓形虫E／SA间接血凝诊断试剂与弓形虫虫体抗原间接血凝诊断试剂的符合率为100％；在人工感染兔血的检测中，E／SA致敏的间接血凝诊断试剂比虫体抗原致敏的间接血凝诊断试剂的阳性检出时间提前2d，显示弓形虫E／SA间接血凝诊断试剂具有早期诊断和生前诊断的应用价值。     

水牛肝片吸虫病间接ELISA诊断方法的建立及应用

以肝片吸虫的分泌－排泄物作为抗原（ES抗原），建立水牛肝片吸虫病间接ELISA诊断方法，并用此方法与粪便检查法检测江苏和安微2省10县（市）302户的307头水牛的血清和粪便；间接ELISA诊断法的最佳工作条件，每乳包被0．2μg抗原，血清稀释度为1：960，二抗稀释度为1：600。结果粪便检查出虫卵的阳性水牛43头，阳性率为14．01％，其中安徽省为11．61％（18／155），江苏省为16．45％（25／152）；用间接ELISA法检测299头水牛血清，阳性87头，阳性率为29．19％，其中安徽省为23．53％，江苏省为34．92％，两种方法的符合率为86．05％。     

犬瘟热病琼脂扩散诊断方法的建立

本文主要阐述了用鸡胚成纤维细胞培养的犬瘟热弱毒疫苗免疫绵羊制备琼扩抗体，用犬瘟热病貉肝脏制备琼扩抗原，建立了琼脂扩散诊断方法。用于犬瘟热死亡动物的肝、脾脏器病毒抗原检出，并初步检测送检病科１０份，与电镜检查结果比较，阳性符合率８５．７％，阴性符合率７５％，总体符合率为９０％。方法特异性强，敏感性高，操作易行，便于推广应用。     

用血清酸滴定法对绵羊进行早期妊娠诊断的研究

采用酸滴定法对人工授精后１７～２１ｄ的１２１只绵羊的１２１份血清经早孕因子检测，进行了早期妊娠诊断。其结果与分娩记录核对，阳性符合率为８９．６１％（６９／７７），阴性符合率为９０．９％（４０／４４），总符合率为９０．０８％（１０９／１２１）。     

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