Biodiversity of avian trypanosomes

We have studied the biodiversity of trypanosomes from birds and bloodsucking Diptera on a large number of isolates. We used two molecular approaches, random amplification of polymorphic DNA (RAPD) method, and sequence analysis of the small subunit ribosomal RNA (SSU rRNA) gene. RAPD method divided the isolates into 11 separate lineages. Phylogenetic analysis of the SSU rRNA gene was congruent with the RAPD. Morphometric analysis of kinetoplast width and cell length was in agreement with molecular data. Avian trypanosomes appeared polyphyletic on SSU rDNA tree; thus, they do not represent a taxonomic group. We propose that all lineages recovered by SSU analysis probably represent distinct species of avian trypanosomes. We discuss possible transmission ways and geographical distribution of new avian trypanosome lineages. Finally, we recommend methods that should be used for species determination of avian trypanosomes.     

莱州市小学生肠道寄生虫感染情况调查

采用改良加藤厚涂片法对莱州市城区和乡镇1916名小学生作肠道寄生虫感染调查,感染率为9.34%。其中土源性寄生虫感染率农村高于城市（P〈0.05）,动物寄生虫感染率城市高于农村（P〈0.01）。     

川西高原藏区德格县肠道寄生虫感染情况调查

目的调查对比分析 1 0年前 (1 991年 )后 (2 0 0 2年 )川西高原藏区常见肠道寄生虫病流行现状。方法采用经济及地形两特征分层整群随机抽样选点 ,用改良加藤氏法检查肠道蠕虫卵 ,对 1 2岁以下儿童用透明胶纸肛拭法检查蛲虫卵。结果该县肠道寄生虫总感染率 1 991年为 5 2 .7% (4 1 0 / 778) ,2 0 0 2年为 3 0 .3 % (1 5 1 / 4 98)。共查见肠道寄生虫 5种 ,1 991年及 2 0 0 2年感染率分别为 :蛔虫 40 .6% ,1 7.3 % ;鞭虫 3 .5 % ,5 .8% ;带绦虫1 3 .8% ,1 1 .2 % ;钩虫 0 .8% ,0 .4% ;蛲虫 1 1 .3 % ,0 %。结论该区 1 0年来总感染率呈下降趋势 ,钩、鞭、蛲虫感染率较轻 ,但 2 0 0 2年学龄儿童 3 0 %左右的蛔虫感染率及农牧民 1 8.9%的带绦虫感染率已成为当地严重的公共卫生问题     

Conduction Defects and Arrhythmias in Chagas' Disease:

Gap Junctions and Humoral Factors in Chagas' Disease. The protozoan parasite Trypanosoma cruzi causes Chagas' disease, a major cause of cardiac dysfunction in Latin Americans. Chagas' disease exhibits both acute and chronic phases, and each may be characterized by cardiac conduction disturbances. In acutely infected cultures of rodent heart cells, synchronized spontaneous beating becomes less regular, and coupling between cells is reduced. The basis of this decreased conduction is apparently in localization of the gap junction protein (Cx43) inside infected cells. Although total Cx43 is normal in infected cells, little is recognizable at appositional membranes. Electrophysiological properties are also altered by this infection. Action potentials are shortened, resting Ca²⁺ levels are elevated, and response to α-adrenergic agonists was altered, compared to controls. Humoral factors may contribute to the conduction defects in chronic Chagas' disease. Sera from chronically infected rabbits produced KC(J abnormalities in Langendorff-perfused rabbit hearts. These findings indicate that chagasic infection may modify ion channel function in the heart, and we suggest that these changes may be manifested in the conduction disturbances that characterize this disease.     

In vitro infection with Theileria parva is associated with IL10 expression in all bovine lymphocyte lineages

The protozoan parasite Theileria parva infects and transforms bovine lymphocytes, giving rise to a fatal lymphoproliferative condition known as East Coast fever. Although immune cattle mount strong cytolytic T lymphocyte responses to the parasite, naive animals appear unable to respond and develop severe immunopathological lesions. We have investigated the patterns of cytokine mRNA expressed by 19 bulk and cloned parasite-infected lymphoblast cell lines using a multiplex PCR system. Considerable variation was observed in the cytokine profiles of these lines and only IL10 was universally expressed. Investigation of cloned lines representing the major bovine lymphocyte populations failed to reveal a lineage-specific pattern of cytokine mRNA expression that could be associated with infection. Nonetheless, analysis of a CD4⁺ T cell clone before and after transformation with the parasite indicated that infection does alter the pattern of cytokine expression, with apparent upregulation of IL10. These observations raise the possibility that IL10 derived from infected cells may influence the immune responses of naive cattle to challenge .     

“双共享”人体寄生虫种质资源库的实践与分析

开放共享的人体寄生虫资源库是开展寄生虫学和寄生虫病防治研究的物质基础。本文在建设人体寄生虫种质资源库中强调"双共享"这一理念和思路。通过实施数据库建设、网站建设和免费开放实物种质资源库等提升其在教学服务、科研服务、科普教育服务和社会服务的水平,以进一步提升华南地区乃至我国寄生虫种质资源的保护和利用水平。     

Chlorpheniramine Analogues Reverse Chloroquine Resistance in Plasmodium falciparum by Inhibiting PfCRT

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湖北省中,小学生及幼儿园儿童肠道寄生虫感染情况调查

目的：了解目前我青少年肠厅生虫感染情况,为制定寄生虫病防治策略提供依据。方法：生理盐水涂片法、磺液涂片法、饱和益水污染法和透明胶带法。结果：检查４０２４名中、小学生和幼儿园儿童,３０７人感染４种寄生虫,感染率７．３０％,蚴虫、钧虫、鞭虫、烧虫的感染率分别为１．７６％、１．０９％和４．２６％,中、小学生与幼儿园儿童的率为５．８２％、５．９９％、８．７６％;农村学生感染率（１６．３４％与城市学生感染率     

Virulence loss and amastigote transformation failure determine host cell responses to Leishmania mexicana

The effect of alterations in virulence and transformation by long‐term in vitro culture of Leishmania mexicana promastigotes on infectivity and immune responses was investigated. Fresh parasite cultures harvested from Balb/c mice were passaged 20 times in vitro. Infectivity was decreased and was completely avirulent after 20 passages. The qPCR results showed a down‐regulation of GP63, LPG2, CPC, CPB2, CPB2.8, CHT1, LACK and LDCEN3 genes after passage seven concomitant with a reduced and absence of infectivity by passages seven and 20, respectively. Parasites at passages one and 20 are referred to as virulent and avirulent, respectively. The growth of avirulent and virulent parasite was affected by conditioned media derived from macrophages or monocytes infected with parasites for 2 h. Giemsa staining showed the failure of avirulent but not virulent parasites to transform to the amastigote stage in infected host cells with both virulent and avirulent modulating the expression of CCL‐22, Tgad51, Cox2, IL‐1, IL‐10, TGF‐β, TNF‐α, Rab7, Rab9 and A2 genes; virulent but not avirulent L. mexicana significantly up‐regulated Th2‐associated cytokines, but down‐regulated Rab7 and Rab9 gene expression. In conclusion, a model for L. mexicana is reported, which is of potential value in studying host–parasite interaction.     

晋北肠道寄生虫病普查

目的 了解肠道寄生虫病在本地区的感染率。方法 选出有代表性的村落，作人群粪便普查和透明胶纸肛检。结果 共调查粪便3055份，查出11种肠道寄生虫，阳性人数为275，阳性率为9％。其中，几种重要的肠道寄生虫感染率分别为：蛔虫(2．2％)；钩虫(0％)；蛲虫(25．9％)。结论 肠道寄生虫病随着人民生活水平提高和医疗卫生条件改善而呈下降趋势，但要在晋北三地区控制和消灭肠道寄生虫病，仍需继续努力。