蓝氏贾第鞭毛虫染色体核型初步观察

目的初步观察蓝氏贾第鞭毛虫细胞分裂过程中典型凝集染色体的形成及其数目。方法用改良TYI-S-33培养基培养贾第虫滋养体。在结束培养前4h弃去旧培养基,加入事先预热的含有秋水仙素(终浓度为0.2μg/ml)的新鲜培养液。低渗处理55min,用甲醇∶冰醋酸(体积比=3∶1)固定液固定。收集细胞、滴片、Giemsa染液染色,光学显微镜观察结果。结果获得了较好的染色体分裂相。贾第虫染色体的数目多数为2n=8条。50个细胞分裂相中,有35个为8条染色体,10个为9条染色体,5个为10条染色体。染色体微小呈小杆状,有时成对,形态相同。结论蓝氏贾第鞭毛虫在分裂过程中形成典型的凝集染色体,染色体数目为2n=10条。     

蓝氏贾第鞭毛虫检测方法的研究进展

蓝氏贾第鞭毛虫是一种重要的水源性人兽共患的寄生原虫,可致人和动物的腹泻.传统的检测方法主要为粪便检查,随着免疫学与分子生物学技术的应用,其免疫学检测和分子生物学检测近年来有了较大的发展.该文就上述研究进展进行综述.     

蓝氏贾第鞭毛虫检测方法的研究进展

蓝氏贾第鞭毛虫是一种重要的水源性人兽共患的寄生原虫,可致人和动物的腹泻.传统的检测方法主要为粪便检查,随着免疫学与分子生物学技术的应用,其免疫学检测和分子生物学检测近年来有了较大的发展.该文就上述研究进展进行综述.     

蓝氏贾第鞭毛虫特异性细胞骨架蛋白——贾第素研究进展

蓝氏贾第鞭毛虫具有由微管、微丝和骨架蛋白构成的高度发达的细胞骨架系统.近年来,贾第虫的细胞骨架与其致病力的密切关系已经得到证实.在参与细胞骨架构成的众多蛋白质中,特异性细胞骨架蛋白——贾第素是其中重要的成分之一.对贾第素的研究不仅可为贾第虫细胞骨架的研究增添新的知识和研究资料,还可为贾第虫病的致病机制及抗贾第虫药物靶点的选择提供实验依据.     

蓝氏贾第鞭毛虫感染致脓胸一例

患者,男,58岁。因咳嗽、发热一周,呕吐一天,左侧胸痛5小时,呕吐一次,于2005年10月14日收入我院呼吸科。有支气管哮喘病史10余年,平均每年发作一次。入院前一周出现咳嗽、咳少量白色黏痰,发热,体温波动于38~39℃,入院前一天进食后呕吐一次,呛咳后出现喘气,在当地医院给予平喘治疗后,喘气好转,但觉左胸部侧壁及后壁疼痛明显。急诊胸片提示:左下肺纹理增粗模糊,左侧肋膈角消失。血常规检查:WBC10.3×109/L,中性粒细胞分类90%。以胸腔积液入院。入院查体:体温37.7℃,呼吸22次/分钟,左肺肩胛下线第9肋间以下叩诊呈浊音,呼吸音减弱,双肺未闻及干…     

蓝氏贾第鞭毛虫的细胞骨架蛋白

蓝氏贾第鞭毛虫是一种重要的肠道致病性原虫,其致病力与细胞骨架密切相关。贾第虫具有高度发达的细胞骨架系统,包括8根鞭毛、1个腹吸盘、中体和funis等,主要由微管蛋白、肌动蛋白、动力蛋白、贾第素及其相关蛋白组成。该文就贾第虫细胞骨架及相关蛋白的结构和功能作一综述。     

蓝氏贾第鞭毛虫基因表达调控的研究进展

蓝氏贾第鞭毛虫是一种重要的致病性寄生虫,人体感染后主要引起腹泻和营养不良等症状。作为一种源真核生物,其基因表达调控机制可能与其他真核生物有较大的区别。本文从蓝氏贾第虫鞭毛虫启动子、转录因子、转录后调节、翻译起始和表观遗传学等方面,对贾第虫基因表达调控的研究进展进行综述。     

抗蓝氏贾第鞭毛虫单克隆抗体的制备和特性研究

用体外培养的四川株蓝氏贾第鞭毛虫滋养休免疫BAIB/c小鼠,以免疫脾细胞与SP2/O骨髓瘤细胞融合,共获得3个分泌抗蓝氏贾第鞭毛虫单克隆抗体的杂交瘤细胞株。这些McAb经鉴定均属lgG_1亚类。选取活性最强的1E_2株McAb对不同贾第虫株进行抗原定位的测定,由IFA显示,该McAb与四川株和山东株滋养休的后1/3表面呈现荧光反应,但与澳大利亚株滋养体表面不显荧光,表明国内株与国外澳大利亚株滋养体表膜抗原存在株间差异。     

青海省人体蓝氏贾第鞭毛虫流行病学调查分析

本文应用分导整群随机抽样法在全省选定３２个调查点，对１６０７９人蓝氏贾第鞭毛虫流行病学调查结果进行了分析，结果表明，我省人群贾第虫流行特征为：（１）人群感染率高，平均为４．６３％。（２）男性高于女性，（３）少数民族感染率高；（４）以牧民的感染为重，（５）小于１５岁的少年儿童感染率高，并有随年龄增长感染率逐渐的趋势。     

Giardia lamblia infection induces different secretory and systemic antibody responses in mice

The adult mouse model of Giardia lamblia infection serves as an excellent animal model to understand the immunological mechanisms involved in the control and clearance of Giardia infection. Little is known about the G. lamblia-specific antigens that stimulate the humoral immune response in this model of giardiasis. We analysed the secretory and systemic antibody responses to G. lamblia during primary and secondary infection in C3H/HeJ adult mice. Faecal IgA and Serum IgG anti-G. lamblia antibodies were observed at week 2 post-infection. Serum IgG responses remained constant over the next several weeks, whereas faecal IgA titres continued to rise from weeks 2-6 post-infection. Western blot analysis revealed that intestinal IgA and serum IgG antibody responses were directed toward several distinct proteins of G. lamblia. Certain proteins appeared to be recognized by both faecal IgA and serum IgG, whereas other antigens were specific for either the secretory or systemic antibody responses. G. lamblia primary and secondary infections were associated with differences in the antibody recognition pattern. The biochemical and immunological characterization of these antigens will help us to better understand the immunobiology of the G. lamblia-host interaction.     

Antigenic variation in Giardia lamblia: infection of congenially athymic nude and scid mice

Athymic nude mice of the outbred Zur:ICR-nu and inbred BALB/c strain and scid mice were infected with a cloned human isolate of Giardia lamblia (GS/M-83-H7). Changes in the expression of the major surface epitope of the intestinal trophozoites (characterized by the binding capacity of monoclonal antibody MoAbG10/4) as well as cellular and humoral immune parameters of the hosts were followed during the course of infection. Self-cure was observed in heterozygous (nu/+) BALB/c mice by day 22 post-infection (p.i.) and in heterozygous (nu/+) Zur:ICR-nu strain by day 65 p.i. Homozygous (nu/nu) mice of both strains remained chronically infected until end of the experiments (day 45 p.i. for BALB/c mice and day 122 p.i. for Zur:ICR-nu mice, respectively). Only heterozygous (nu/+) mice were able to mount a gut-associated (Peyer's patch) lymphoproliferative response to G. lamblia antigen. Therefore, T-cell dependent mechanisms were necessary for a self-cure. Antigenic variation occurred in all nu/+ and nu/nu animals of both strains. Trophozoites expressing the major surface epitope (assessed by direct immunofluorescence with FITC-labelled MoAb G10/4) decreased to zero by day 22 p.i. In contrast, the proportion of trophozoites expressing the major surface epitope in infected scid mice remained at the initial level (greater than 99%) until termination of the experiment (day 25 p.i.); therefore, antigenic variation did not occur. All nu/nu and nu/+ mice but not scid mice demonstrated a humoral immune response to G. lamblia antigen. These experiments suggest functional B-cell dependent mechanisms are most likely responsible for the surface antigen switch. Transfer of infection occurred naturally from experimentally infected scid-mice to their mother, proving the initial antigenic surface variant remains unchanged after encystment and subsequent excystment followed by infection in a new host.     

A longitudinal study of Giardia lamblia infection in north-east Brazilian children

OBJECTIVE: To evaluate the epidemiology of Giardia lamblia infection, investigate factors which might be associated with clinical manifestations and recurrence, and examine the role of copathogens in disease course. METHODS: Prospective 4-year cohort study of children born in an urban slum in north-eastern Brazil. RESULTS: Of 157 children followed for > or = 3 months, 43 (27.4%) were infected with Giardia. The organism was identified in 8.8% of all stool specimens, and although found with similar frequency in non-diarrhoeal (7.4%) and diarrhoeal stools (9.7%), was more common in children with persistent (20.6%) than acute diarrhoea (7.6%, P=0.002). Recurrent or relapsing infections were common (46%). Children with symptomatic infections had significantly lower weight-for-age and height-for-age than asymptomatic children. Copathogens were not associated with disease course. CONCLUSION With its protean clinical manifestations, Giardia may be associated with substantial morbidity amongst children in Brazil.     

蓝氏贾第鞭毛虫遗传多样性研究进展

蓝氏贾第鞭毛虫是全球危害人类健康的重要寄生性原虫之一。由于该虫宿主包括几乎所有脊椎动物,虫种的基因型和表现型变异较大,因而其宿主特异性及人畜共患传播问题尚未完全解决。近年来,贾第鞭毛虫病的广泛流行已引起人们对其遗传多样性的关注。基于PCR的分子鉴定方法及多种分子标志的应用使得对贾第鞭毛虫种群的遗传结构有了更多了解。该文就蓝氏贾第鞭毛虫遗传多样性的研究进展作一综述。     

Tumour necrosis factor alpha contributes to protection against Giardia lamblia infection in mice

Giardia lamblia is a ubiquitous parasite that causes diarrhoea. Effective control of Giardia infections in mice has been shown to involve IgA, T cells, mast cells and IL-6. We now show that Tumour necrosis factor alpha (TNFalpha) also plays an important role in the early control of giardiasis. Mice treated with neutralizing anti-TNFalpha antibodies or genetically deficient in TNFalpha were infected with the G. lamblia clone GS/(M)-H7. In both cases, mice lacking TNFalpha had much higher parasite numbers than controls during the first 2 weeks of infections. However, anti-parasite IgA levels, mast cell responses, and IL-4 and IL-6 mRNA levels do not appear significantly altered in the absence of TNFalpha. In addition, we show that mice infected with G. lamblia exhibit increased intestinal permeability, similar to human Giardia infection, and that this increase occurs in both wild-type and TNFalpha deficient mice. We conclude that TNFalpha is essential for host resistance to G. lamblia infection, and that it does not exert its effects through mechanisms previously implicated in control of this parasite.     

蓝氏贾第鞭毛虫的免疫逃避机制

蓝氏贾第鞭毛虫(Giardia lamblia,简称贾第虫)是一种世界性分布的机会性致病原虫,能够引起以腹泻为主要表现的贾第虫病,严重影响人类尤其是儿童的健康和发育。在贾第虫感染过程中,宿主的非特异性和特异性免疫系统均会产生强烈的抗贾第虫效应,但贾第虫通过抗原漂变、L-精氨酸饥饿等机制逃避和抑制宿主的免疫反应,引起宿主的长期或反复感染。本文对宿主的抗贾第虫免疫以及贾第虫的免疫逃避机制做一综述。     

蓝氏贾第鞭毛虫滋养体有丝分裂的初步观察

目的观察体外培养的蓝氏贾第鞭毛虫滋养体有丝分裂。方法用改良的TYI-S-33培养基培养贾第虫。从培养第6h开始,每间隔2h取分裂的细胞直至第24h,制备涂片,Giemsa染液染色,用光镜和透射电镜观察细胞分裂状况。结果有丝分裂前期:染色质凝集形成细长的染色质丝;中期:形成大小约1μm的棒状染色体,且全部排列在细胞核中央,或分散在核内;后期:姐妹染色单体分开,向细胞核两极移动,核膜拉长;末期:核膜中间向内缢束呈葫芦状,细胞核缢裂成两个子核,随即进行胞质分裂。结论蓝氏贾第鞭毛虫滋养体有丝分裂与典型真核细胞相似,但分裂期核膜始终存在,为半开放式分裂。