山丹马6-磷酸葡萄糖脱氢酶及葡萄糖磷酸异构酶的多态性研究

用淀粉凝胶电泳及琼脂覆盖技术对山丹马的血液红细胞6磷酸葡萄糖脱氢酶和葡萄糖磷酸异构酶的电泳变异进行了测定。在6磷酸葡萄糖脱氢酶座位发现了3种表现型,即FF,FD和FS,其频率分别为0.958,0.021和0.021。在葡萄糖磷酸异构酶座位发现了两种表现型,即II和FI,其频率分别为0.771和0.229。等位基因频率直接通过表型计算出:PGDF为0.979,PGDD为0.0104,PGDS为0.0104;GPIF为0.1146,GPII为0.8854。亲子关系排除概率在6PGD和GPI座位点分别为0.1009和0.0912。两座位的个体识别概率分别为0.081和0.353。     

隐性白羽肉鸡(农大系)的染色体核型和G-带分析

本文运用鸡胚成纤维细胞系制备染色体和G显带技术,对隐性白羽肉鸡的染色体核型和G带带型进行了研究。结果表明:其二倍体染色体数目2n=78,性染色体组成为ZZ(公)和ZW(母)。根据着丝粒位置,1号,8号,Z和W为中着丝粒染色体;2号和7号为近中着丝粒染色体;4号为近端着丝粒染色体;而3,5,6,9,10,11和12号均为端着丝粒染色体,而另26对染色体为无法辨别的点状染色体。研究分析了前12对常染色体和性染色体的G带带型,并绘制了包含165条带(其中75条阳性带)的G-带模式图。     

胸腺素α_1对墟岗黄鸡免疫器官组织学结构的影响

本试验研究了不同剂量的胸腺素α1(Tα1)对墟岗黄母鸡免疫器官指数和组织学结构的影响。结果表明:0.015mg/kg体重剂量的Tα1可显著提高鸡免疫器官指数,可使胸腺皮质增宽,髓质胸腺小体数和胸腺细胞数增加;脾脏胸腺依赖区和法氏囊依赖区细胞增殖;高剂量Tα1则引起法氏囊髓质局部细胞变性和坏死。     

胚胎干细胞向神经细胞定向诱导分化方法的研究进展

胚胎干细胞具有自我更新和多向分化潜能,有望成为治疗神经系统疾病重要的种子细胞来源。如何高效地诱导胚胎干细胞向特定神经细胞分化是目前研究的热点。本文就胚胎干细胞定向分化成神经细胞的3种方法:RA诱导法、谱系选择法和SDIA法及其移植研究做一综述。     

鸡源耐安普霉素大肠杆菌耐药表型研究

进行了安普霉素耐药大肠杆菌耐药表型的研究.采用常规方法和生化鉴定管对有过安普霉素用药史的鸡场分离的鸡源病原性大肠杆菌进行鉴定,并用试管二倍稀释法测定其最低抑菌浓度(MIC),筛选出鸡源安普霉素耐药大肠杆菌;采用药敏纸片法研究了这些耐药菌对安普霉素等14种抗菌药物的敏感性.共筛选出7株对安普霉素耐药的鸡源性大肠杆菌,这些耐药菌株全部对安普霉素、妥布霉素、奈啶酸、多西环素和阿莫西林耐药;大部分对庆大霉素、链霉素、卡那霉素、壮观霉素也呈现耐药.对新霉素的耐药较低,对阿米卡星高度敏感.部分交叉耐药现象的存在揭示对安普霉素等氨基糖苷类药物产生耐药性的菌株,其他抗生素也可能对它们失去疗效.     

Costs of studying veterinary science: a national survey of fourth year veterinary students

OBJECTIVE: To estimate the costs to the student of veterinary education. METHOD: A questionnaire was completed by 180 fourth-year veterinary students from the four veterinary schools in Australia. Frequencies and median costs were estimated using the SAS System for Windows 95. RESULTS: The median direct living costs were about $5000 per academic year, but were higher in Sydney and for those with additional expenses including children, pets and cars. Other costs associated with the course including text books, equipment and travel to practical work were of the order of $1000, and income foregone while doing practical work placed additional burdens on some. More than half the students from Sydney and Murdoch needed to work to provide basic necessities. Most of this work involved interaction with animals or people. The percentage of Queensland and Melbourne students needing to work was lower, 47 and 24 respectively, and fewer of those worked directly with animals or people. The students expected to repay a median of $14,000 after they graduate, with 70% of this being due to the Australian government as part of the Higher Education Contribution Scheme. CONCLUSIONS: Although parents contributed an average of between one-third and one half of the costs of obtaining a veterinary degree, the extent of parental contributions was very uneven and almost one half of all students needed to work to provide basic necessities. The average total debt on graduation was about half the annual starting salary, but those starting the course from 1997 are subject to much higher charges, and their average debt is likely to exceed one year's salary.     

中药“驱螨净”对兔螨病的治疗试验

用中药“驱螨净”治疗２３只螨病患兔。结果：一次用药后治愈率达９１．３％，初步证实该药剂对治疗兔螨病具有显著的作用。     

Cyclosporin: applications in small animal dermatology

Abstract Cyclosporin has been increasingly used for the treatment of skin diseases in small animals. Reported uses include the treatment of atopy, cutaneous lupus erythematosus, feline acquired alopecia resembling pseudopelade of humans, pemphigus erythematosus, pemphigus foliaceus, perianal fistulae and sebaceous adenitis. In addition, cyclosporin has been used anecdotally for several other skin diseases. Few side effects have been noted at doses therapeutic for dermatologic diseases. Current suggestions for monitoring, and the value of trough cyclosporin serum concentrations for prediction of toxicity and efficacy are discussed.     

Evolution of High-level,Multiple Anthelmintic Resistance on a Sheep Farm in Malaysia

Anthelmintic resistance in nematode parasites of sheep and goats on a government farm in north Malaysia was monitored over a 3-year period (1997–2000). The faecal egg count reduction test (FECRT) was conducted on young sheep at the beginning and end of this period. Changes in management, designed to reduce the selection pressure for the development of anthelmintic resistance, were also implemented during this time. By far the most important parasite problem was Haemonchus contortus. In 1997, this nematode was found to be resistant to levamisole, with suspected resistance to closantel and moxidectin. However, when the FECRT was repeated 3 years later, its resistance status had become much more severe, with resistance to benzimidazole, levamisole and ivermectin, and suspected resistance to moxidectin. This rapid evolution to multiple anthelmintic resistance is a major concern that needs to be arrested. There is an urgent need to evaluate other control strategies that incorporate livestock management, the `smart' use of drugs and non-chemotherapeutic approaches, such as biological control agents.     

毛细管电泳技术及其在兽药残留分析中的应用

随着人们生活水平的提高和养殖业的发展,兽药残留对食品安全的危害日益受到人们的关注.中国作为畜禽产品重要出口国,将在相当长的一段时间内必须面对兽药残留所形成的贸易壁垒.因此,必须加强兽药残留检测技术的研究.文章就毛细管电泳技术及其在兽药残留分析中的应用做一综述.