牛肝片吸虫及其对胆管损伤的组织化学和扫描电镜观察

牛肝片吸虫的成虫体表有环行排列的、呈“牛舌状”的棘,其顶部有?数个齿;迷走幼虫体表无体棘,仅有环状排列的、粗细不一的皱纹,其头锥较长,约为虫体的1/2,口腹吸盘是圆形,上有细皱纹和数个乳突。受损职管的大部分功能消失殆尽。而增生小胆管则功能旺盛。浸润的嗜酸粒细胞、淋巴细胞功能较活跃。浸润的细胞中未见巨噬细胞。探讨了虫体与胆管损伤的关系。     

弥渡县牛肝片吸虫病流行调查

为了解弥渡县牛肝片吸虫感染情况,采用粪便虫卵检查法进行牛肝片吸虫病的流行调查。结果表明,在检查的960头牛中,阳性牛220头,阳性率为22.92%。其中坝区阳性率为14.06%,半山区为28.75%,山区为25.94%;黄牛阳性率为24.58%,水牛为21.25%;阳性牛最小年龄为1.5岁,最大为13岁,阳性率随年龄增长而提高;阳性牛的每克粪便虫卵数(EPG)最高216枚,最低3枚。该调查研究揭示了肝片吸虫病在弥渡县的牛中感染较广泛,尤其是半山区、山区较高。     

Bayesian hierarchical modelling to enhance the epidemiological value of abattoir surveys for bovine fasciolosis

Four classes of Bayesian hierarchical models were evaluated using an historical dataset from an abattoir survey for fasciolosis conducted in Victoria, Australia. The purpose of this analysis was to identify areas of high prevalence and to explain these in terms of environmental covariates. The simplest of the Bayesian models, with a single random effect, validated the use of smoothed maps for cartographic display when the sample sizes vary. The model was then extended to partition the random effect into spatially structured and unstructured components, thus allowing for spatial autocorrelation. Rainfall, irrigation, temperature-adjusted rainfall and a remotely sensed surrogate for rainfall, the normalised difference vegetation index (NDVI), were then introduced into the models as explanatory variables. The variable that best explained the observed distribution was irrigation. Associations between prevalence and both rainfall and NDVI that were significant in fixed effects models were shown to be due to spatial confounding. Nevertheless, provided they are used cautiously, confounded variables may be valid predictors for the prevalence of disease.     

肝片吸虫神经系统结构组化定位

以美蓝，硫酸铜-硝酸银及乙酰胆碱法对肝片吸虫神经系统结构进行组化定位，为其神经肽相关研究探明结构基础。研究结果表明，仅乙酰胆碱法可以将肝片吸虫的神经系统结构定位出来，肝片吸虫的神经系统发达，中枢神经系统由1对咽前侧神经节（脑神经节），1对粗大的腹神经索，畔 细的成对的背神经索和侧神经索及横向神经联合组成；外周神经系统由各纵行神经索及横向神经联合发出的纤细神经纤维交织形成的神经网构成，扁形动物梯状神经系统模式在肝片吸虫中的表现并不典型。     

实验肝片吸虫感染对大鼠机体自由基代谢影响的研究

通过大鼠感染肝片吸虫复制感染模型 ,研究肝片吸虫感染后血清抗氧化功能的变化。 60只大鼠随机分成感染组和对照组 ,每组 30只。感染组大鼠一次口服 2 5个囊蚴 ,对照组不感染。于感染前 (0周 )和感染后 (1 ,3,5,7,9周 )采集血样 ,检测感染后谷胱甘肽过氧化物酶(GSH Px)、超氧化物歧化酶 (SOD)、过氧化物酶 (CAT)活性和丙二醛 (MDA)含量的变化。结果表明大鼠感染肝片吸虫后 ,感染组血清中GSH Px先升高后下降 ,SOD活性无明显变化 ,CAT活性在感染后下降 ,MDA含量在前 5周变化不明显 ;说明自由基参与了肝片吸虫病的发病过程     

一氧化氮（NO）在山羊感染肝片吸虫过程中作用

8～12月龄雄性山羊(n=5)人工感染肝片吸虫后,每周定时颈静脉采血1次,用硝酸还原酶法检测血清中一氧化氮(NO)的动态变化,并观察了NO与IgG抗体、嗜酸性粒细胞(EOS)之间的相关性.结果,山羊在感染后第1周,NO含量明显低于对照组,第2～6周或高或低呈波动趋势,自第6周后明显高于对照组,其中第7～8周达高峰,即(93.73±17.233)μmol/L,第7周与对照组相比P<0.01,第8、10周P<0.05;IgG抗体用间接ELISA最早在感染后第2周就可检出,并从第4周起保持高水平,第8～9周达到最高峰,血清中NO含量与IgG水平的相关系数为r＝0.511(P<0.05),而对照组的NO与IgG相关系数为r＝0.25(P>0.05);感染山羊在整个试验期间的EOS明显升高,其中第8周达峰值(P<0.01).本试验结果表明,NO、IgG和EOS在山羊感染肝片吸虫过程中的变化趋势基本一致并呈正相关,且与虫体在宿主体内的移行、发育密切关联,显示NO、IgG和EOS共同参与宿主抗肝片吸虫感染的作用.     

免疫印迹分析试验感染肝片吸虫和大片吸虫绵羊的IgG应答

免疫印迹(Westernblot)分析试验感染肝片吸虫和大片吸虫绵羊的抗片形吸虫分泌捧泄产物(FhESP和FgESP)IgG应答，结果表明，FhESP中分子质量在17．1～21．6ku之间的4条主要蛋白带仅被肝片吸虫感染以后(0WPI以后)的血清识别且不被对照组血清识别；FgESP中分子质量在19．0～71．1ku之间的6条主要蛋白带仅被大片吸虫感染以后(0WPI以后)的血清识别且不被对照组血清识别。     

肝片形吸虫与巨片形吸虫的DNA和氨基酸含量的分析

本文对肝片形吸虫和巨片形吸虫进行了组织化学探讨。结果表明：肝片形吸虫和巨片形吸虫的ＤＮＡ含量不同，二者比值为２：３，且所含１７种氨基酸种类相同，含量却不相同，某些氨基酸含量差别很大。     

Determining the Prevalence and Seasonality of Fasciola hepatica in Pasture-based Dairy herds in Ireland using a Bulk Tank Milk ELISA

Background

Fasciola hepatica is a helminth parasite of global importance in livestock, with major economic impact. However information on F. hepatica infections in Irish pasture-based dairy herds is limited. Therefore this study was conducted in order to determine the prevalence, seasonality and management factors associated with F. hepatica. A total of 319 Irish dairy herds were selected for this study. Bulk tank milk (BTM) samples were collected from 290 dairy farms on a quarter year basis, while from a further 29 dairy farms BTM samples were collected on a monthly basis to provide a more detailed pattern of F. hepatica exposure in Irish herds. BTM samples were analysed using a commercially available F. hepatica antibody detection ELISA. Furthermore, within-herd prevalence of F. hepatica was assessed in a subset of these 29 herds (n = 17); both individual serum samples and bulk tank milk samples were collected.

Results

A within-herd prevalence of ≤ 50 % was found for herds with negative bulk tank milk samples. The mean prevalence of the 290 study herds was 75.4 % (Range 52 %–75.1 %), with the highest prevalence being observed in November (75.1 %). The seasonal pattern of F. hepatica shows elevated antibodies as the grazing season progressed, reaching a peak in January. A significant association was found between F. hepatica and age at first calving.

Conclusion

This study demonstrates that F. hepatica is present in a large proportion of Irish dairy herds and provides a basis on which control practices, particularly in adult dairy cows, can be reviewed.     

急性感染肝片吸虫水牛血细胞免疫反应的研究

 研究了水牛急性感染肝片吸虫后血细胞免疫反应在抗感染中的作用机制：结果表明．水牛感染后．ＷＢＣ的总体水平在整个感染期高于对照组；ＤＣ中的嗜酸性粒细胞（％）在第 ２周即显著高于对照组直到 １９周．以后下降并接近对照组；嗜中性粒细胞（％）在第５～１６周低于或明显低于对照组．以后两组接近；淋巴细胞（％）在感染后的第２～５周低于或明显低于对照组．以后接近．至第１４周又低于或明显低于对照组直至２１周；单核细胞和嗜碱性粒细胞（％）在整个实验期无显著差异；Ｔ－淋巴细胞（％）从第１周起显著下降，Ｂ－淋巴细胞（％）显著升高．１１周后均与对照组无明显差异；ＲＢＣ－ＣＲ１花环率在２～１６周显著低于对照组．以后逐渐恢复接近对照组，而ＲＢＣ－ＩＣ花环率在２～１８周高于或明显高于对照组。提示水牛在急性感染肝片吸虫后，血细胞的特异性和非特异性免疫反应变化剧烈，共同参与抗肝片吸虫感染机制。