Thyroid Hormone-disrupting Effects and the Amphibian Metamorphosis Assay

There are continued concerns about endocrine-disrupting chemical effects, and appropriate vertebrate models for assessment of risk are a high priority. Frog tadpoles are very sensitive to environmental substances because of their habitat and the complex processes of metamorphosis regulated by the endocrine system, mainly thyroid hormones. During metamorphosis, marked alteration in hormonal factors occurs, as well as dramatic structural and functional changes in larval tissues. There are a variety of mechanisms determining thyroid hormone balance or disruption directly or indirectly. Direct-acting agents can cause changes in thyroxine synthesis and/or secretion in thyroid through effects on peroxidases, thyroidal iodide uptake, deiodinase, and proteolysis. At the same time, indirect action may result from biochemical processes such as sulfation, deiodination and glucuronidation. Because their potential to disrupt thyroid hormones has been identified as an important consideration for the regulation of chemicals, the OECD and the EPA have each established guidelines that make use of larval African clawed frogs (Xenopus laevis) and frog metamorphosis for screening and testing of potential endocrine disrupters. The guidelines are based on evaluation of alteration in the hypothalamic-pituitary-thyroid axis. One of the primary endpoints is thyroid gland histopathology. Others are mortality, developmental stage, hind limb length, snout-vent length and wet body weight. Regarding histopathological features, the guidelines include core criteria and additional qualitative parameters along with grading. Taking into account the difficulties in evaluating amphibian thyroid glands, which change continuously throughout metamorphosis, histopathological examination has been shown to be a very sensitive approach.     

胆翘注射液急性和亚慢性毒性试验

旨在评价胆翘注射液的毒性,为临床安全用药提供理论依据。以昆明小鼠为研究对象,进行急性和亚慢性毒性试验。在急性毒性试验中,给予小鼠不同浓度的胆翘注射液来测定胆翘注射液的半数致死量和最大耐受量;在亚慢性毒性试验中,小鼠以(10、5、2.5g/kg)不同剂量连续腹腔注射给药28d,在给药第28天观察小鼠的临床体征、体重及饲料利用率、血常规、血液生化指标和病理组织学变化。结果显示,急性毒性试验各剂量组小鼠均无死亡,无法测出LD_(50),最大耐受量为20g/kg。亚慢性毒性试验中用药组小鼠的临床体征、体重及饲料利用率、血常规、血液生化指标与空白组小鼠相比,无显著差异(P0.05),组织病理学观察,实质器官无异常病变。表明胆翘注射液实际无毒,安全性好。     

獭兔链球菌的分离与鉴定

对通辽市某獭兔种免场采集到的病死兔组织进行细菌分离,通过形态鉴定、生化鉴定、药敏试验、动物致病性试验等一系列诊断,证实链球菌感染是引起兔死亡的主要原因。根据药敏试验结果,对免群进行针对性治疗．使病情得到有效控制。     

Evaluation of single and comparative intradermal tuberculin tests for tuberculosis eradication in caprine flocks in Castilla y León (Spain)

Goats can act as reservoirs for tuberculosis (TB) infection. The main etiological agents of TB in goats are Mycobacterium caprae and Mycobacterium bovis and they infect also a wide range of domestic and wild animals and humans. Control programmes based mainly on the application of single and comparative intradermal tuberculin (SIT and SCIT respectively) tests are being implemented in certain regions of Spain with a high density of caprine flocks as Castilla y León, including goats with epidemiological relationship with cattle. The aim of this study was to evaluate the performance of the intradermal tests in naturally TB-infected caprine flocks from this region. The study was performed using data from 17,450 goats in 54 different flocks that were classified as TB-infected in the control programmes executed in 2010 and 2011. Data from 1237 goats from 7 dairy flocks depopulated after the first intradermal testing were used to estimate the sensitivity (Se) using bacteriology as the gold-standard. Overall Se of the SIT test using the severe interpretation was 43.9% (CI 95%, 40.4–47.4) and decreased to 38.8% (CI 95%, 35.5–42.3) using the standard interpretation. Overall Se of the SCIT test ranged between 21.3% (CI 95%, 17.6–25.4) and 7% (CI 95%, 4.9–9.8) depending of the interpretation criteria. A significant weak positive correlation was found between age and skin fold thickness (Spearman’s test p < 0.05). Results from this study yielded, in general, low Se values probably due the systematic detection and slaughter of reactors as a consequence of the eradication programme in previous years or the presence of factors that may interfere in the diagnosis. Therefore, these results suggest the necessity of including ancillary diagnostic tools and/or strict interpretation criteria to maximize detection of positive animals in infected settings.     

中药复方对人工感染雏鸡大肠埃希菌病及沙门菌病的防治效果观察

为验证中药复方对鸡大肠埃希菌病和沙门菌病的临床效果,对人工感染大肠埃希菌和沙门菌鸡进行防治试验,用O78、O1、O2型大肠埃希菌菌株和鸡白痢沙门菌株对试验组鸡进行人工感染后,分为中药复方高、中、低剂量组,抗生素和健康、阳性对照组。结果表明,中药复方防治两类疾病疗效可靠,效果明显,其中以高剂量组防治效果最好。对人工感染引起的鸡大肠埃希菌病和鸡白痢的保护率为92%,治愈率分别为82%和88%。     

鸡骨型白血病免疫琼扩与放射摄片诊断的比较

为了探索特异性免疫学诊断方法对鸡骨型白血病(OP)的检测效果。用双盲法分批采样同时进行羽髓琼脂扩散试验和胫骨X线摄片检查对比,共检834只鸡(433羽属天然自发OP鸡群,401羽属人工诱发实验鸡群)。结果羽髓琼扩试验的OP阳性检出率为3．48％(29／834：)。阳性病理符合率为75．86％(22／29)。阳性误诊(假阳性)率24．13％(7／29),阴性误诊(假阴性)率36．15％(291／805)。而X线摄片检查的OP阳性检出率为38．37％(320／834)。X线阳性完全可获病理组织学证实,不存在假阳性或假阴性。把禽白血病羽髓琼扩试验试用于检测鸡骨型白血病尚属初次报道,其阳性检出率低而误诊率高,尚不宜作OP检测手段。放射摄片诊断的阳性检出率高而误诊率低,可快速诊断,故适用于OP检疫。     

A quantitative assessment of the validity of animal-health surveys using stochastic modelling

This paper presents a stochastic simulation model to evaluate the efficacy of regional or national surveys aimed at identifying infection in populations of animals. The process of evaluation involves specification or calculation of cluster-level test sensitivity and specificity, which are derived from two probability distributions of the number of individual-level positive tests expected from non-infected and infected clusters, respectively. Probability distributions for the number of positive clusters expected in a situation of freedom from infection and under various levels of cluster prevalence are specified and used to determine survey properties (the survey being considered a diagnostic system), and ROC curves are drawn. Likelihood ratios allow investigators to state the extent to which a survey result is more likely to be observed if the region or country is infected at a given prevalence than if it is free from infection. The result of a survey carried out to investigate the presence of porcine reproductive and respiratory syndrome (PRRS) in Switzerland is used to illustrate this approach. The model can be adapted to a wide range of survey designs.     

北欧4种燕麦在果洛地区的引种栽培试验

在果洛拉加乡黄河谷地及西哈垄沟内,对引进的４种北欧燕麦进行的引种栽培试验结果表明：４种燕麦中ＹＴＡ较早熟,全生育天数１０４天;ＬＥＮＡ干草产量最高（４２３９９ｋｇ／ｈｍ２）;ＭＥＬＹＳ从籽实产量、茎叶比、营养成份等综合性状评价,都优于其它品种;ＮＥＯＮ的饲草品质最为优秀     

应用鸡胚接种试验研究中草药的抗新城疫病毒作用

为了筛选出高效的抗新城疫病毒(Newcastle disease virus,NDV)中草药,采用鸡胚接种试验测定了常用清热解毒中草药的体外抗NDV作用.结果表明矮地茶、侧柏叶、贯众、诃子、虎杖、白蔹、夏枯草、黄连对新城疫病毒具有较好的杀灭作用.     

箭筈豌豆新品种DUS测试指南研制—测试性状评价和参照品种筛选

以国际植物新品种保护联盟(UPOV)制定的植物新品种DUS(distinctness, uniformity and stability)测试指南总则(TG/1/3)、箭筈豌豆DUS测试指南(TG/32/7)等技术文件为指导,对箭筈豌豆DUS测试指南的核心技术内容:测试性状和参照品种等开展了研究。在国内外共收集到51个箭筈豌豆品种,并进行连续2年的田间观测。观测性状总计31个,包括UPOV箭筈豌豆DUS测试指南中的23个性状,以及本实验发现有特异性的8个新增性状。对每个测试性状的表达状态、观测时期、测定方法、观测数量等进行了分级和详尽描述。共筛选出32个参照品种(国际21个, 我国11个),确定了123个表达状态。并对UPOV 箭筈豌豆DUS测试指南中“外种皮底色”和“种子形状”表达状态的分级进行了补充。本研究结果可为我国箭筈豌豆新品种 DUS 测试指南的制定奠定技术基础,对促进我国箭筈豌豆品种保护、审定和育种工作具有重要的意义。