Stage–specific antigens of Hymenolepis microstoma recognized in BALB/c mice

Antigenicity of eggs (oncospheres), cysticercoids and adults (with immature segments only) of the bile duct tapeworm Hymenolepsis microstoma was analysed using immunoblotting techniques and indirect immunofluorescent antibody (IFA) techniques with immune sera of BALB/c mice (i) infected with different doses of cysticercoids, (ii) during patent or prepatent infection with the lumen phase of the parasite or (iii) sensitized with live or dead eggs. Antibody responses detected by IFA test and immunoblotting showed that antigenicity of eggs (oncospheres) differed from that of cysticercoids and adults. Single worm infections were sufficient to stimulate antibody responses. Mice which had patent infection showed strong antibody responses to all three (egg (oncosphere), cysticercoid, adult) antigens, while mice given two prepatent infections showed some antibody responses to cysticercoid and adult antigens only. Although the normal intermediate hosts of this parasite are arthropods, antibodies to some major egg (oncosphere) antigens were produced in mice given eggs of this parasite orally, either through inoculation of eggs or ingestion of faeces contaminated with eggs. Antibodies were not produced in mice dosed with non-viable eggs. The results are consistent with the hypothesis that cestode parasites express phase- (or stage-) specific antigens.     

Expulsion of Hymenolepis nana from mice with congenital deficiencies of IgE production or of mast cell development

The roles of IgE and mast cells on expulsion of adult Hymenolepis nana from the intestine were examined in mice. IgE-dependency was determined by comparing congenitally IgE-deficient SJA/9 and IgE-producing SJL/J mice infected with 50 H. nana eggs. Anti-H. nana IgE antibody was detected at three weeks post infection (p.i.) in SJL but not in SJA mice. The number of adult worms in the intestines of SJA and of SJL mice were similar at two weeks, but significantly more were found in SJA mice at three weeks p.i. Treatment of mice with anti-ɛ antibody also resulted in an increased worm burden at three weeks, suggesting participation of IgE in expulsion of H. nana. Intestinal mastocytosis was induced by infection regardless of the IgE status of the mice. Mast cell-dependency was tested in mast cell-deficient W/W^u and in normal littermate +/+ mice infected with 100 H. nana eggs. Anti-H. nana antibody was detected in both groups of mice at three weeks p.i. Worm expulsion seemed to be mast cell dependent because expulsion was less complete in W/W^u mice at three weeks p.i. Peripheral blood eosinophilia was comparable at three weeks p.i. in both IgE and mast cell sufficient and deficient mice. These results suggest that IgE and mast cells participate in the expulsion of H. nana adults from intestine in mice.     

长膜壳绦虫卵和短膜壳绦虫卵透射电镜观察

用透射电镜观察两种膜壳绦虫卵,长膜壳绦虫卵自外向内观察到的结构是卵壳外层、卵壳内层、透明层、膜状结构层、胚膜外层、胚膜内层、六钩蚴膜。最内为六钩蚴,六钩蚴主要分为六蚴区和腺样组织区。短膜壳绦虫卵基本结构与上述相似,自外向内包括菲薄的卵壳、膜状结构层、透明层、胚膜,最内为六钩蚴,亦分六钩区和腺样组织区,但六钩蚴的小钩两者结构不一致。     

The microanatomy and fine structure of the rostellum ofHymenolepis diminuta

The microanatomic arrangement of the muscular, nervous, and excretory systems as well as the organization of the tegument are described for the rostellum ofHymenolepis diminuta. An inner circular and an outer longitudinal layer of muscle comprise the rostellar capsule, delimiting the rostellum from the scolex proper. A similar muscular arrangement surrounds an apical invagination of the rostellar tegument, the anterior canal. Elements of the excretory and nervous systems enter the rostellum basally through a discontinuous region of the capsule. Although excretory canals extend into the rostellum, flame cells and their associated collecting ducts are absent. The rostellar nervous system is comprised of a single bilateral pair of ganglia, which provide motor innervation of the anterior canal, and the circular muscles of the rostellar capsule; it also receives dendrites from apical uniciliate sensory receptors. The tegument lining the anterior canal and covering the apical rostellum is syncytial and continuous with the tegument of the scolex proper. Twelve to 15 cytons are radially arranged around the anterior canal. They stain selectively with paraldehyde-fuchsin between days 3 and 35 postinfection, but are clearly tegumental, not neurosecretory elements. The appearance of ovoid granules in the rostellar tegumentary cytons coincides with the onset of fuchsinophilia, but the granules persist despite the subsequent loss of this staining characteristic. Intact granules are secreted into the lumen of the anterior canal, although their function has not been ascertained.     

封闭群子午沙鼠寄生虫感染的研究及其药物净化

[摘要] 目的 了解子午沙鼠种群寄生虫感染状况,并有针对性选择药物及合适剂量驱除子午沙鼠体内外寄生虫,使子午沙鼠得到净化,为建立清洁级子午沙鼠种群奠定基础,为制定子午沙鼠寄生虫检测标准提供参考依据。方法 对封闭群子午沙鼠寄生虫感染情况进行调查研究,选择胺菊?氯菊酯、吡喹酮、替硝唑三种药物,分为高、中、低剂量对子午沙鼠用药,观察子午沙鼠体内外寄生虫驱除情况。结果 在子午沙鼠体内检出鼠三毛滴虫和短膜壳绦虫两种体内寄生虫,体外寄生虫有鼠肉螨。高、中、低剂量组能不同程度杀死子午沙鼠体表食肉螨,鼠肉螨用1％的胺菊?氯菊酯药浴子午沙鼠三次即可驱除子午沙鼠体表的鼠肉螨,有螨动物只数为零。吡喹酮中剂量组（31mg/kg）有完全杀死子午沙鼠体内短膜壳绦虫的作用,且为最佳给药剂量。替硝唑中剂量组（42mg/kg）为净化子午沙鼠体内鼠三毛滴虫的最佳剂量。结论 现有的子午沙鼠体内有鼠三毛滴虫和短膜壳绦虫感染,体外有鼠肉螨寄生,三种抗寄生虫药物具有选择性驱除这些寄生虫的作用。     

不同浓度的阿苯达唑体外抗短膜壳绦虫机理探讨

目的：为研究阿苯达唑对短膜壳绦虫及虫卵的杀灭机制。方法：应用形态学方法,观察比较不同浓度的阿苯达唑对短膜绦虫的体外杀伤作用。结果：48h各组虫体活力均明显减弱,72h高浓度组虫体均死亡,虫体随着药物浓度的升高和作用时间的延长,体表损伤愈加严重,组织结构破坏明显,实质区细胞出现核固缩,核碎裂现象,48h虫卵出现形态改变,数量明显减少。结论：表明阿苯达唑对短膜壳绦虫及虫卵均有较强的损伤作用。     

Anticestodal Activity of Trifolium repens. Extract

ABSTRACT

Trifolium repens. L. is an herbal plant that is used in the folk medicine of the Naga tribes of India as a deworming remedy. This study deals with evaluating its anticestodal activity using experimental Hymenolepis diminuta. Rudolphi infections in albino rats. Doses of T. repens. aerial shoots extract 200 and 500?mg/kg reduced the mean fecal egg counts of H. diminuta. by 47.72% and 54.59% and worm recovery rate by 60.00% and 40.00%, respectively. Praziquantel, the standard cestocidal drug, reduced the mean fecal egg count by 65.90% and worm recovery rate by 26.67%. The study suggests that the aerial shoots of T. repens. bear anticestodal properties and supports its use in the traditional medicine system.     

Alteration of the rat cecal microbiome during colonization with the helminth Hymenolepis diminuta

The microbiome is now widely recognized as being important in health and disease, and makes up a substantial subset of the biome within the ecosystem of the vertebrate body. At the same time, multicellular, eukaryotic organisms such as helminths are being recognized as an important component of the biome that shaped the evolution of our genes. The absence of these macroscopic organisms during the early development and life of humans in Western culture probably leads to a wide range of human immunological diseases. However, the interaction between the microbiome and macroscopic components of the biome remains poorly characterized. In this study, the microbiome of the cecum in rats colonized for 2 generations with the small intestinal helminth Hymenolepis diminuta was evaluated. The introduction of this benign helminth, which is of considerable therapeutic interest, led to several changes in the cecal microbiome. Most of the changes were within the Firmicutes phylum, involved about 20% of the total bacteria, and generally entailed a shift from Bacilli to Clostridia species in the presence of the helminth. The results point toward ecological relationships between various components of the biome, with the observed shifts in the microbiome suggesting potential mechanisms by which this helminth might exert therapeutic effects.     

野生树鼩肠道蠕虫感染调查及分析

目的调查野生树鼩(Tupaia belangeri Chinensis)感染肠道蠕虫的主要种类并进行鉴定,为今后树鼩寄生虫检测提供形态学参考,为实验树鼩寄生虫控制提供依据。方法采集203只野外来源的树鼩新鲜粪便,虫卵采用常规粪便直接涂片以及孵化后显微镜观察;绦虫采用压片、固定染色,以及线虫经透明后体视镜观察,虫卵与成虫相对应鉴定。结果野生树鼩肠道蠕虫的总感染率为75.86%,主要感染种类有3种,经鉴定为长膜壳绦虫、奇口线虫和粪类圆线虫,感染率分别为27.67%,30.06%和51.52%。三种蠕虫的混合感染率为4.55%。两种线虫虫卵在树鼩粪便中多为含胚胎形态。结论野生树鼩肠道蠕虫的感染率较高。对野外引入的新种源必须隔离检疫,进行针对性的药物治疗,才能有效地控制肠道寄生虫病的传播。     

Experimental hymenolepiasis of rats: preliminary data on histopathological changes of visceral organs

Pathomorphological changes of intestine, liver, spleen and adrenals of rats experimentally infected with Hymenolepis diminuta are described 24 days post infection. Major structural alterations in intestinal wall include lesions of the mucosa, fusions of villi, damage of the epithelial layer and its replacement by flattened cells with pycnotic nuclei. In addition, tunica muscularis and tunica submucosa become thicker and there are numerous lymphocytes among enterocytes. At moderate infections, the changes in the spleen indicate activation of the lymphopoiesis and enhanced protective functions while, in heavily infected rats, the B zone of the spleen showed signs of emaciation. Liver histology of infected rats showed dilatation of sinusoids and the presence of destructive alterations in the parenchyma, necrotic cells and cells with pycnotic nuclei; in heavily infected animals, the necrotic cells were grouped in foci. In adrenal glands, alterations concern mostly zona fascicularis, which is interpreted as mobilization of cytoplasmic lipid inclusions in order to increase the intensity of the steroid hormone synthesis. The degree and character of histopathological changes depended on the intensity of infection.