肽聚糖对鲫鱼嗜水气单胞菌灭活疫苗免疫增强效果的研究

为了探讨肽聚糖在鱼类抗嗜水气单胞菌（Aeromonas hydrophila，AH）感染中的免疫佐剂作用，用添加A3a肽聚糖的饲料投喂接种F-AH疫苗的彭泽鲫（Carassius auratus var．pengze）；通过测定鲫白细胞吞噬活性、血清和体表黏液溶菌酶活性、抗体效价以及活菌攻毒后的免疫保护率，证明肽聚糖与F-AH疫苗联合使用，鲫体表黏液和血清溶菌酶活性、白细胞吞噬活性、抗体效价以及活菌攻毒后的免疫保护率均显著提高，表明A3a肽聚糖是F-AH疫苗的良好佐剂，能增强鱼类F-AH疫苗免疫应答。     

PEG对嗜水气单胞菌疫苗制备与免疫效果影响的研究

为评价聚乙二醇(PEG)作为超声介质及疫苗佐剂对嗜水气单胞菌疫苗免疫效果的影响,本研究将该疫苗与常规疫苗分别经腹腔注射免疫接种锦鲤成鱼,检测血细胞吞噬百分率、吞噬指数、抗菌活力、抗体效价及免疫保护力等指标,评价疫苗效果.结果表明PEG6000作为佐剂制备的疫苗,其各指标均高于对照组及其他试验组.PEG6000疫苗免疫保护力达到77.8％,高于常规灭活疫苗22.2％,表明PEG6000作为佐剂制备的疫苗效果最好.     

嗜水气单胞菌重庆WL3-X2分离株灭活疫苗对大鲵的免疫保护效果的研究

为评估重庆地区分离的嗜气单胞菌WL3-X2分离株对大鲵的免疫原性,本研究将嗜水气单胞菌WL3-X2分离株经福尔马林灭活,作为免疫原,通过腹腔注射途径间隔2周两次免疫健康大鲵,并检测其体内血清抗体、溶菌酶、补体C3及其免疫保护效应。结果显示,免疫嗜水气单胞菌灭活菌能够显著提高大鲵血清抗体滴度、溶菌酶活性和补体C3含量,首免35 d后这3项指标均达到峰值。此外,对初免4周后的大鲵经肌肉注射0.2 m L浓度为1.0×10~8 cfu/m L剂量的嗜水气单胞菌WL3-X2分离株,进行攻毒保护试验。结果表明,免疫组的相对免疫保护率为66.7%。本研究结果表明,嗜水气单胞菌地方分离株灭活菌对大鲵具有显著免疫保护效力,可以作为大鲵预防嗜水气单胞菌感染的候选疫苗。     

罗非鱼出血病病原鉴定及疫苗的研究

从患出血病罗非鱼的血液、肝、脾分离出嗜水气单胞菌（Ａｅｒｏｍｏｎａｓ ｈｙｄｒｏｐｈｉｌａ）,经动物回归和理化试验鉴定,确诊嗜水气单胞菌为罗非鱼出血病病原;用分离菌制成的饵料吸附型疫苗进行田间试验,免疫组罗非鱼保护率为８７．１％,未免疫组存活率为５９．９％,两组间差异极显著（Ｐ〈０．０１）。     

罗非鱼出血病病原鉴定及疫苗

从惠出血病罗非鱼血液、肝脏、脾脏中分离到一株细菌,经理化鉴定,该菌为嗜水气单胞菌,动物回归试验阳性,认为该罗非鱼出血病是嗜水气单胞菌引起。用该分离菌制成的饵料及附型疫苗田间免疫罗非鱼成活率达87．1％,未免疫组成活率仅59．9％。     

黄芪多糖对杂交鲌的非特异性免疫作用

在饲料中添加定量的黄芪多糖,探讨黄芪多糖对杂交鲌的免疫调节作用。用添加不同含量黄芪多糖的饲料,连续投喂杂交鲌30 d,测定试验鱼的增重、血清凝集抗体效价、溶菌酶的活性、谷丙转氨酶的活性、血清总蛋白含量和白细胞吞噬活性。进行攻毒嗜水气单胞菌活菌的复感染试验,测定相对免疫保护率。结果显示添加黄芪多糖的饲料投喂杂交鲌生长速度较对照组稍快;试验组鱼体的溶菌酶活性和白细胞吞噬活性,比对照组鱼体均有所提高;谷丙转氨酶活性的检测结果表明试验组鱼体的肝功能有所改善;对嗜水气单胞菌的抵抗能力,与空白对照组相比有所增强。说明黄芪多糖对杂交鲌免疫机能具有调节作用。     

超声灭活大肠杆菌制造禽大肠杆菌病疫苗

超声灭活大肠杆菌继之以辐射处理是一种制备大肠杆菌病疫苗最有效的方法。该法制备的疫苗比用其他方法（热，甲醛，辐射等）灭活制备的疫苗的保护率都高，该法制的O2：1株超声疫苗同时能抵抗同源菌株O73：K80的攻击，其保护率与攻毒当天测得的大肠杆菌抗体效价成正相关，免疫后5天仅能测得低效价抗体，保护率为20％，免疫后5－18天可 得高效价抗体，攻毒后只有极少数出现病变，每个攻毒组中，无病变鸡比有病变鸡抗体效价高，显示鸡病变程度与抗体效价之间存在相关性。     

奶牛乳房炎性乳房链球菌GapC重组蛋白的免疫保护性研究

为研究奶牛乳房炎性乳房链球菌GapC蛋白的免疫保护性,本研究采用纯化后的GapC重组蛋白与免疫佐剂乳化后制备疫苗,免疫家兔后采用间接ELISA法检测抗体效价,并以小鼠为实验动物进行攻毒试验.结果显示,抗体效价高达1:128 000,GapC蛋白免疫组对乳房链球菌的保护率较高,达70％,而全菌体免疫组的保护率仅为30％,表明GapC蛋白具有很高的免疫原性,为奶牛乳房炎的预防控制和进一步研究有效疫苗提供实验依据.     

“兔瘟”疫苗中不同佐剂对免疫效果的影响

利用“兔瘟”病毒枣(?)毒株(RVZ85)制备的不含佐剂疫苗,甘油佐剂疫苗、氢氧化铝佐剂疫苗和矿物油佐剂疫苗免疫接种易感家兔,定期测 HI 抗体效价并进行人工攻毒试验.结果证明,不含佐剂的疫苗产生的保护力最早,免疫后三天即4/4保护.用四种疫苗免疫接种后一年内,对攻毒的保护率均为100%.四种疫苗中,以矿物油佐剂疫苗免疫兔的HI抗体效价最高,氢氧化铝佐剂疫苗次之,甘油佐剂疫苗及不含佐剂疫苗的HI效价较低。氢氧化铝佐剂疫苗在室温保存8.5个月,免疫兔4/4保护;室温保存14个月.免疫兔2/3保护:4℃保存14个月,免疫兔4/4保护.     

甲壳素对猪传染性胃肠炎免疫调节作用的研究

研究了甲壳素对猪传染性胃肠炎疫苗的免疫调节作用；用浓碱法处理甲壳素可获得吸附能力强的佐剂，但物理性状不适合用于疫苗佐剂：壳聚糖可用作制备具有良好水溶性的疫苗佐剂，经与白油和蜂胶等佐剂比较，表明该佐剂对猪传染性胃肠炎具有一定的免疫调节作用。即4种佐剂的疫苗在免疫后14d，壳聚糖疫苗组抗体效价显著高于其它组；免疫后30～120d油乳剂疫苗组抗体效价显著高于其它组。     

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