Effect of dietary supplementation with flaxseed oil or vitamin E on sheep experimentally infected with Fasciola hepatica

The effects of two diets supplemented with flaxseed oil (FO) or vitamin E (VE) were studied in sheep infected with Fasciola hepatica. The control group (CO), not supplemented, had higher weight gain and faecal egg count (P < 0.05) at the end of the study. At necropsy, the number (71.2 ± 26.5) and size of flukes were lower in the FO group (P < 0.01), probably due to the higher levels of white blood cells and lymphocytes (P < 0.01). This group also had higher red blood cell and haematocrit values (P < 0.01). The CO group had more severe hypoproteinaemia and hypoalbuminaemia, due to having the highest fluke burden (123.0 ± 35.2), and also the highest IgG1 titre (P < 0.01). The diet did not affect production or gene expression levels of IFN-γ and IL-4. On the other hand, the supplementation with VE led to a reduction in adult fluke burden (97.7 ± 39.9) and lower lipid oxidation in the liver (P < 0.001).     

水牛感染肝片吸虫后血清抗氧化功能的动态变化

经粪便和Ｄｏｔ－ＥＬＩＡ检查确认无肝片吸虫感染的２０头雄性去势水牛,分两系列试验。系列Ⅰ实验中８头水牛随机分成感染组（５头）和对照组（３头）,感染组每头每天口服６０个肝片吸虫囊蚴,连续２０ｄ;系列Ⅱ实验中１２头水牛分成感染组（９头）和对照组（３头）,感染组每头一次口服１６００个肝片吸虫囊蚴。在感染前及感染后每周颈静脉采血,分离血清,测定丙二醛（ＭＤＡ）、过氧化物酶（ＣＡＴ）、超氧化物歧化酶（ＳＯＤ）和谷胱甘肽过氧化物酶（ＧＳＨ－Ｐｘ）的活力。在系列Ⅱ实验中,ＭＤＡ在感染后１５周内显著高于对照组,以后下降,至１９～２２周显著低于对照组;ＧＳＨ－Ｐｘ、ＳＯＤ和ＣＡＴ均表现在感染初期显著低于对照组,以后呈波动性变化,至感染后期显著高于对照组。在系列Ⅰ实验中,ＭＤＡ仅在感染后第７和第８周显著高于对照组,以后则显著低于对     

肝片形吸虫体内5—羟色胺的免疫反应分布

应用间接免疫荧光技术，发现肝片形吸虫头部咽的两侧各有一强的５－羟色胺（５－ＨＴ）荧光集落（脑神经节），由其发出的神经干分布于虫体的背腹及两侧，神经干继续发出细小分支直至皮肌层和吸盘等。生殖（睾丸，子宫，卵模和卵黄腺纵隔等）和消化系统（咽和肠管壁等）亦有５－ＨＴ免疫反应分布。揭示肝片形吸虫体内不仅存在５－ＨＴ，而且存在色胺能神经系统，证明了５－ＨＴ为肝片形吸虫的神经递质。     

肝片吸虫免疫显性抗原基因的筛选及鉴定

为筛选出特异的肝片吸虫诊断候选抗原,拓展诊断靶标,利用肝片吸虫阳性血清筛选肝片吸虫cDNA表达文库,获得肝片吸虫特异性抗原基因,采用RT-PCR技术扩增目的基因,连接表达载体pET-32a(+),构建重组质粒,转化入感受态细胞BL21(DE3)中,利用IPTG对重组蛋白进行诱导表达,通过SDS-PAGE及Western blot技术对蛋白表达情况进行鉴定。结果显示:经筛选获得了17个肝片吸虫免疫显性抗原基因,其中假定蛋白Fh010935为肝片吸虫特异性抗原基因;扩增得到的Fh010935核苷酸序列大小为144 bp,编码48个氨基酸,A+T含量为55.56%;Fh010935蛋白由1个α-螺旋,2个β-折叠和3个β-转角构成,具有3个抗原表位,推测该蛋白可能具有较好的抗原性;重组蛋白主要以包涵体形式表达,分子量大小约24 ku,可以被肝片吸虫感染阳性血清特异性识别,具有较好的反应原性。提示:假定蛋白Fh010935可作为肝片吸虫病诊断候选抗原,为疾病诊断制剂的开发提供前期基础。