ETMIC-2基因表达产物对人工感染柔嫩艾美耳球虫雏鸡的保护及病理学研究

采用大肠杆菌表达鸡艾美耳球虫微线蛋白(ETMIC—2)，对石歧杂小公雏在1、2周龄按分组以不同剂量分别肌注免疫，3周龄人工感染强毒柔嫩艾美耳球虫孢子化卵囊，4周龄全部捕杀，进行增重、盲肠病变和免疫淋巴器官病理组织学观察。结果表明，全部试验组增重率均高于红对照组，其中两组超过白对照组；盲肠病变均低于红对照组；免疫淋巴器官发生不同程度的增生，尤其是胸腺，盲肠扁桃体及脾脏，淋巴滤泡增大，淋巴细胞明显增殖。此结果可以提示，适量的ETMIC—2基因表达产物免疫雏鸡后，再进行柔嫩艾美耳球虫的强毒攻击，能刺激机体的免疫淋巴组织器官产生免疫应答反应，对机体具有较好的保护力。     

柔嫩艾美耳球虫杨凌株3-1E基因表达产物的初步免疫效果研究

用柔嫩艾美耳球虫(Eimeria tenella子孢子表面抗原基因原核细胞表达产物免疫雏鸡,观察其对球虫攻击的免疫保护作用.将可溶性重组蛋白和包涵体重组蛋白经肌肉注射分别于7日龄、14日龄两次免疫罗曼小公雏,同时设攻虫对照组和空白对照组,于第2次免疫后1周(28日龄)用1 ×104个E.tenella卵囊进行攻毒,观察其诱导产生的保护力.结果表明,3-1E可溶性蛋白组免疫无论从卵囊计数、盲肠病变计分和相对增重均优于包涵体免疫组.说明3-1E基因在大肠杆菌中的表达产物对鸡柔嫩艾美耳球虫的攻击有一定的免疫保护作用.     

鸡柔嫩艾美耳球虫SO7基因的原核表达及动物免疫试验

为了研究鸡柔嫩艾美耳球虫SO7基因原核表达重组蛋白的免疫效力,分析其在鸡抗柔嫩艾美耳球虫感染中对鸡平均增重、抗球虫指数(ACI)、减少盲肠病变和卵囊数量中的作用,从柔嫩艾美耳球虫孢子化卵囊中提取总RNA作为模板,用RT-PCR扩增出SO7基因片段,再应用DNA重组技术将SO7基因克隆到原核表达载体pET32a(+)中并用IPTG诱导表达。SDS-PAGE结果显示,pET32a(+)-SO7表达的目的蛋白约为40ku,主要以包涵体形式存在。用纯化的重组蛋白进行动物免疫试验显示,SO7重组蛋白在鸡抗柔嫩艾美耳球虫感染中有较好的免疫保护作用,能够显著提高鸡柔嫩艾美耳球虫感染鸡的平均增重和抗球虫指数(ACI),对减少盲肠病变和卵囊数量也有部分作用。     

鸡柔嫩艾美耳球虫生殖细胞特异性蛋白的免疫保护效果评价

为探讨鸡柔嫩艾美耳球虫(Eimeria tenella)生殖细胞特异性蛋白(HAP2)对球虫感染的免疫保护作用,将HAP2重组蛋白(rEtHAP2)加弗氏完全佐剂或弗氏不完全佐剂免疫雏鸡后,用E. tenella孢子化卵囊感染雏鸡,以雏鸡增重效果、卵囊排出量、肠道病变记分、血清抗体水平、淋巴细胞转化水平,评估rEtHAP2的免疫保护作用,并设PBS免疫对照组、正常饲养对照组。结果显示:rEtHAP2免疫组雏鸡的平均体重、日增重、血清抗体水平、淋巴细胞转化水平,均显著高于PBS免疫对照组(P0.05);卵囊排出量,肠道病变记分则显著低于PBS免疫对照组(P0.05);抗球虫指数ACI值为176.18,保护效果良好。研究表明生殖细胞特异性蛋白HAP2对柔嫩艾美耳球虫感染具有良好的免疫保护作用,可成为柔嫩艾美耳球虫新型疫苗的候选抗原。     

鸡柔嫩艾美球虫鸡胚继代致病力的研究

通过鸡胚系列继代已获得了变位艾美尔球虫、柔嫩艾美尔球虫及毒害艾美尔球虫的致弱虫株.我们曾对日本柔嫩艾美尔球虫进行了51代鸡胚连续培养,发现在鸡胚内的繁殖性能和对鸡胚的致死性没有变化.但接种雏鸡后,与感染的原代虫株相比,盲肠很少有严重损伤和出血,同时鸡的体重和采食量都增加.在柔嫩艾美尔球虫的子孢子中发现有 PAS 阳性颗粒,被确认为是支链淀粉。用原代虫株曾做了系列试验,发现子孢子内支链淀粉的含量与虫株的生命力和运动活性及其在宿主细胞内的发育有关。柔嫩艾美尔球虫的子孢子中的支链淀粉被认为     

ELISA检测DLV虫苗免疫鸡抗体消长规律的研究

将柔嫩、毒害、巨型艾美耳球虫的孢子化卵囊制成可溶性抗原，用酶联免疫吸附试验检测鸡球虫双重致弱多凤苗虫苗、为柔嫩、毒害、巨型艾美耳球虫三价苗免疫鸡血清抗球虫抗体的消长规律。     

鸡柔嫩艾美球虫DNA疫苗pcDNA4．0（C）-pEtK2-IL-2对其他球虫的交叉保护力

将柔嫩艾美球虫DNA疫苗pcDNA4．0（c）-pEtK2-IL-2以50μg分别对14日龄和21日龄雏鸡进行胸部肌肉注射免疫，28日龄对各未免疫组与免疫组鸡分别口服接种柔嫩艾美球虫、巨型艾美球虫、堆形艾美球虫和毒害艾美球虫孢子化卵囊，36日龄剖杀，分析比较免疫保护效果。结果显示，柔嫩艾美球虫攻毒免疫试验组与柔嫩艾美球虫攻毒未免疫对照组比较，增重、盲肠病变记分、OPG值差异显著（P〈0．05），免疫保护效果明显，抗球虫指数（ACI）达186．50；而巨型艾美球虫、堆形艾美球虫和毒害艾关球虫攻毒免疫试验组的ACI分别为147．85、142．71和153．82，增重、盲肠病变记分、OPG值和ACI与相应的攻毒未免疫对照组比较，均有不同程度改善，免疫保护效果不明显。表明，该DNA疫苗对柔嫩艾美球虫的攻击具有完全免疫保护作用，而对巨型艾美球虫、堆形艾关球虫、毒害艾美球虫的攻击具有部分交叉保护力。     

"肉鸡球虫病及其综合防治措施"专栏(三)鸡胚传递配子母细胞疫苗产生的母源免疫力可防止新生雏鸡感染艾美尔球虫

给繁殖母鸡口服接种柔嫩艾美尔球虫鸡胚传递配子母细胞佐剂疫苗,并于加强免疫后2周收集所产鸡蛋进行孵化;出壳雏鸡于7日龄用柔嫩艾美尔球虫(本地分离株)的孢子化卵囊进行攻击,结果免疫母鸡所产雏鸡的球虫卵囊排出量较对照组母鸡所生雏鸡减少70%以上,且无鸡只死亡,而五分之四的对照组雏鸡死于球虫病.这些结果表明,鸡胚传递配子母细胞疫苗所产生的母源免疫力能够防止后代雏鸡受到柔嫩艾美尔球虫的感染.     

鸡胚传递配子母细胞疫苗产生的母源免疫力可防止新生雏鸡感染艾美尔球虫

给繁殖母鸡口服接种柔嫩艾美尔球虫鸡胚传递配子母细胞佐剂疫苗,并于加强免疫后2周收集所产鸡蛋进行孵化;出壳雏鸡于7日龄用柔嫩艾美尔球虫(本地分离株)的孢子化卵囊进行攻击,结果免疫母鸡所产雏鸡的球虫卵囊排出量较对照组母鸡所生雏鸡减少70%以上,且无鸡只死亡,而五分之四的对照组雏鸡死于球虫病。这些结果表明,鸡胚传递配子母细胞疫苗所产生的母源免疫力能够防止后代雏鸡受到柔嫩艾美尔球虫的感染。     

柔嫩艾美尔球虫郑州株对鸡致病性试验

通过用孢子化球虫卵囊感染豫州褐壳蛋鸡913系35日龄公雏,测定了柔嫩艾美尔球虫郑州株的致病力。结果表明:该球虫株毒力较强,每只鸡接种5000～50000个卵囊均引起严重的临床盲肠球虫病和典型病变,增重率和饲料转化率显著低于对照组,每只鸡接种3～5万个卵囊引起严重死亡(60％),接种5000～1万个卵囊引起部分死亡(20％)。建议在应用该球虫株进行鸡球虫病药物防治和免疫防治效果评价时,攻虫剂量以2万个卵囊为宜。     

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.     

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.     

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     

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 -