国内蓝氏贾第鞭毛虫研究

蓝氏贾第虫鞭毛虫(GiardialambliaStile,1915,亦称G.intestinalis或G.duodenalis,简称贾第虫)是一种机会性致病肠道原虫,一种全球性的引起人和动物腹泻的常见病原体。以往国内对本虫的危害性及其在生物进化上的地位缺乏足够的重视,实验研究起步较晚,在七十年代以前几处于?..     

实验感染C57 BL/6N小鼠粪内蓝氏贾第鞭毛虫tim基因检测

建立蓝氏贾第鞭毛虫感染动物模型 ,用PCR技术对感染动物粪内该虫tim基因进行检测 ,探讨蓝氏贾第鞭毛虫基因检测方法。用人源蓝氏贾第鞭毛虫河北株 (CD)和江苏株 (XZ)的包囊分别接种两组C5 7BL 6N小鼠 ,于接种后第 6天、1 0天和 1 4天收集粪便标本 ,采用酚 氯仿法提取总DNA。将提取液分别按 1 0 0 、 1 0 - 1 、 1 0 - 2 和 1 0 - 3稀释并纯化。根据该虫磷酸丙糖异构酶 (Triosephosphateisomerase,tim)基因合成 1对特异性引物 ,采用PCR技术分别扩增各个稀释度的样本。结果贾第虫阳性样本均被扩增出相应基因的 1条 683bp长的片段 ,纯化后的各个稀释度样本的PCR检测阳性率随稀释倍数的增加而增高。本研究结果为贾第虫感染基因检测方法的进一步研究提供了实验资料。     

用PCR扩增tim基因检测蓝氏贾第鞭毛虫

采用聚合酶链反应 (PCR)对蓝氏贾第鞭毛虫 (Giardialamblia)的磷酸丙糖异构酶 (triosephosphateisomerase ,缩写为tim)基因进行特异性扩增 ,结果扩增出 1条 6 83bp的DNA片段。此方法的特异性可高达10 0 % ,而其它DNA样本 ,如日本血吸虫 (Schistosomajaponicum)、刚地弓形虫 (Toxoplasmagondii)、微小隐孢子虫 (Cryptosporidiumparvum)、溶组织内阿米巴 (Entamoebahistolytica)、旋毛虫 (Trichinellaspiralis)和阴道毛滴虫 (Trichomonasvaginalis) ,以及人体血细胞等均未出现扩增反应。本法的敏感性也很高 ,可检测到0 4pg贾第虫包囊的DNA。 13株来自不同地理位置和 或宿主的贾第虫DNA样本在PCR中均各产生 1条长为 6 83bp的目的片段。上述结果表明本实验建立的检测贾第虫的PCR方法有效     

用PCR扩增tim基因检测蓝氏贾第鞭毛虫

采用聚合酶链反应(PCR)对蓝氏贾第鞭毛虫(Giardia lamblia)的磷酸丙糖异构酶(triose phosphate isomerase,缩写为tim)基因进行特异性扩增,结果扩增出1条683bp的DNA片段.此方法的特异性可高达100%,而其它DNA样本,如日本血吸虫(Schistosoma japonicum)、刚地弓形虫(Toxoplasma gondii)、微小隐孢子虫(Cryptosporidium parvum)、溶组织内阿米巴(Entamoeba histolytica)、旋毛虫(Trichinella spiralis)和阴道毛滴虫(Trichomonas vaginalis),以及人体血细胞等均未出现扩增反应.本法的敏感性也很高,可检测到0.4pg贾第虫包囊的DNA.13株来自不同地理位置和/或宿主的贾第虫DNA样本在PCR中均各产生1条长为683bp的目的片段.上述结果表明本实验建立的检测贾第虫的PCR方法有效.     

梨形鞭毛虫滋养体的单克隆抗体产生及其特性(文摘)

梨形鞭毛虫是一种寄生于鼠小肠中的原生动物寄生虫,梨形鞭毛虫感染鼠可构成人贾第氏虫病的动物模型以及探讨鞭毛虫滋养体抗原的肠免疫应答的实验途径。鼠单克隆抗体(McAb)是由梨形鞭毛虫滋养体表面抗原来生产的,经非肠道免疫后的BALB/c鼠脾淋巴细胞与P3/NS1/1-Ag4-1骨髓瘤细胞融合而得到B-细胞杂交瘤。梨形鞭毛虫     

用PCR扩增tim基因检测蓝氏贾第鞭毛虫

采用聚合酶链反应(PCR)对蓝氏贾第鞭毛虫(Giardia lamblia)的磷酸丙糖异构酶(triose phosphate isomerase,缩写为tim)基因进行特异性扩增,结果扩增出1条683bp的DNA片段.此方法的特异性可高达100%,而其它DNA样本,如日本血吸虫(Schistosoma japonicum)、刚地弓形虫(Toxoplasma gondii)、微小隐孢子虫(Cryptosporidium parvum)、溶组织内阿米巴(Entamoeba histolytica)、旋毛虫(Trichinella spiralis)和阴道毛滴虫(Trichomonas vaginalis),以及人体血细胞等均未出现扩增反应.本法的敏感性也很高,可检测到0.4pg贾第虫包囊的DNA.13株来自不同地理位置和/或宿主的贾第虫DNA样本在PCR中均各产生1条长为683bp的目的片段.上述结果表明本实验建立的检测贾第虫的PCR方法有效.     

蓝氏贾第鞭毛虫病与免疫

蓝氏贾第鞭毛虫病是由蓝氏贾第鞭毛虫(以下简称贾第虫、贾第虫病)寄生于小肠所致的一种传染病。主要症状有腹泻、吸收障碍和体重减轻。贾第虫是人类的重要致病性原虫之一,     

贾第虫研究──Ⅰ．西蒙氏贾第虫（Giardia simoni）滋养体和包囊对实验动物的感染

作者从自然感染西蒙氏贾第虫（Ｇｉａｒｄｉａｓｉｍｏｎｉ）的金黄地鼠肠道内和粪便中分离、收集滋养体和包囊，分别经口感染大鼠、小鼠、豚鼠和兔子。结果表明兔子和脉鼠均不感染，大鼠、小鼠均不同程度地感染该虫，且４周龄大鼠比８周龄大鼠更易感（Ｐ＜０．０５），而在小鼠中成年鼠与老年鼠对西蒙氏贾第虫的敏感性没有差异（Ｐ＞０．０５）。滋养体在感染动物的肠道内主要分布于十二指肠前段，中前段和中段。同时观察到结肠和直肠内有包囊，这表明该虫在大鼠、小鼠体内完成了其生活史。作者还对感染前后的滋养体作了蛋白银和铁苏木精染色比较，二者在形态上完全相同。     

Ⅰ级封闭群ICR小白鼠肠道内寄生虫寄生关系探讨

目的了解小白鼠体内寄生虫感染情况以及寄生关系。方法采用解剖法取小白鼠肠道内容物于光镜下检测。结果共检出肠道寄生虫4种：微小膜壳绦虫、管状线虫、四翼无刺线虫和鼠贾弟鞭毛虫，并且以混合感染为主。结论贾弟鞭毛虫与其它3种寄生虫之间共生；微小膜壳绦虫与管状线虫之间竞争；微小膜壳绦虫与四翼无刺线虫之间竞争；管状线虫与四翼无刺线虫之间共栖。     

郑州市某医院儿童肠道寄生虫感染情况调查

目的了解郑州地区儿童肠道寄生虫感染情况,为制定肠道寄生虫病防治措施提供参考依据。方法采用卢戈氏碘液染色法、饱和蔗糖溶液漂浮法和改良抗酸染色法对儿童新鲜粪便样品进行检查。结果共调查1996份粪便样品,肠道寄生虫总感染率为1.5%,发现蓝氏贾第鞭毛虫、环孢子虫、隐孢子虫、阿米巴原虫和粪类圆线虫5种肠道寄生虫,其感染率分别为0.6%、0.5%、0.1%、0.3%和0.1%。不同性别、不同季节儿童肠道寄生虫感染情况差异无统计学意义（P〉0.05）。蓝氏贾第鞭毛虫和阿米巴原虫主要发现于春季和冬季,隐孢子虫和环孢子虫仅发现于夏季和秋季。结论郑州地区儿童土源性肠道寄生虫感染率显著下降,以机会性原虫感染为主,应进一步加强健康卫生教育。     

萎缩小肠粘膜上皮细胞凋亡及增殖细胞核抗原表达变化的研究

目的：探讨小肠粘膜萎缩的发生机制。材料和方法;采用原位末端标记和免疫组化的方法,对正常和萎缩肠粘膜上皮细胞凋亡的发生,分布及增殖细胞核抗原（ＰＣＮＡ０的表达进行对比研究。结果：调亡细胞主要位于肠绒毛的顶部,萎缩小肠粘膜上皮细胞凋亡的发生率明显高于正常小肠（Ｐ〈０．０５）;而ＰＣＮＡ阳性表达细胞主要位于腺隐窝区,萎缩小肠粘膜上皮细胞ＰＣＮＡ的阳性计数较正常小肠显著降低。     

萎缩小肠粘膜上皮细胞凋亡及其相关基因表达的研究

目的：探讨细胞凋亡与小肠粘膜萎缩发生之间的关系。材料和方法,采用原位末端标记,免疫组化和ＲＴ－ＰＣＲ的方法,对正常小肠粘膜上皮和萎缩小肠粘膜上皮细胞凋亡的发生及其相关基因的表达进行对比研究。结果萎缩小肠粘膜上皮细胞凋亡的发生率明显高于正常小肠（Ｐ〈０．０５）;Ｃ－ＭＹＣ在萎缩小肠绒毛顶部异常高表达,ＢＡＸ和ＢＣＬ－２呈弥散分布,ＢＣＬ－２在萎榨小肠粘膜上皮的表达显著低于正常小肠（Ｐ〈０．０５）,Ｂ     

胎儿阑尾淋巴组织发生与炎性样肠腺关系的探讨

共收集12～38周胎儿阑尾标本68例,取其中段作部分连续切片,光镜观察。结果发现:淋巴组织出现于第17周’17～20周的半数阑尾可见淋巴组织,21周后阑尾淋巴组织的出现率为90%左右。淋巴组织的形态在28周以前以淋巴细胞群为主,29周以后以淋巴小结为主。阑尾的淋巴组织多,其炎性样肠腺的出现率高。相反,切面上的炎性样肠腺数越多,其淋巴组织就越丰富。     

MICROSATELLITE INSTABILITY IN INTESTINAL- AND DIFFUSE-TYPE GASTRIC CARCINOMA

To investigate the role of genetic instability in the development of intestinal- and diffuse-type gastric cancers, six microsatellite loci were analysed in 98 carcinomas of the two main histotypes, at both early and advanced stages of progression, and in five preneoplastic lesions. RER+ phenotype frequency proved to be significantly higher ( P =0·013) in intestinal (23 per cent) than in diffuse cancers (5 per cent) and slightly higher in advanced (19 per cent) than in early (12 per cent) tumours. When comparing early and advanced tumours of the same histotype, a similar frequency was found for diffuse tumours (4 per cent vs. 6 per cent), and an increase from 19 to 30 per cent for intestinal cancers. Instability at more than one locus was limited to intestinal tumours and replication errors were also detected in an intestinal dysplasia. On the whole, these data suggest that genetic instability has an important and early role in gastric carcinogenesis of the intestinal type and a less important role in gastric carcinogenesis of the diffuse type. Most tumours of this panel had previously been characterized for p53 gene mutations. p53 screening was extended to all samples, to investigate the possible association between gene mutations and microsatellite instability. Analysis showed a trend ( P =0·07, Fisher's exact test) towards a negative association between these two genetic lesions in tumours of the intestinal type. © 1997 John Wiley & Sons, Ltd.     

肠道微生态与肠黏膜屏障研究进展

人类肠道内含有大量微生物群,这一复杂而重要的生态系统构成影响人体的生理功能。肠道黏膜是机体的重要屏障,正常的肠道微生态和肠黏膜屏障相互作用,共同维持机体的内稳态。一旦肠道微生态被破坏,肠道菌群失衡,并通过各种途径导致肠黏膜屏障受损,进而有害病原菌入侵。     

Technical report: results of immunological tests on faecal extracts are likely to be extremely misleading.

Clinical investigation of gut immunity is difficult because of the need to study intestinal tissues or secretions directly. Others have reported that immunoglobulins, antibodies and cytokines can be detected in saline extracts of faeces. We have assessed the validity of this approach by measuring immunoglobulins, albumin, alpha 1-antitrypsin and isotype-specific antibodies in matched samples of faeces and whole gut lavage fluid. Results were compared as estimated output per day, and by using haemoglobin as a common reference substance. Samples were obtained from 10 patients with active inflammatory bowel disease and 10 with other benign GI diseases. For immunoglobulins, albumin and antibodies, the amount detected in faeces varied from < 0.01% to 35.5% (based on estimated daily output) and < 0.01% to 18.5% (based on haemoglobin) of the amount known to be produced in the gut from results of assays on whole gut lavage fluid (WGLF); there were significantly higher rates of recovery in faecal specimens from patients with active gut inflammation than from other patients. Detection rates and titres of specific antibody in faeces were even lower than those for immunoreactive IgA. These data indicate that immunological tests on saline extracts of faeces do not represent the true status of the gut humoral immune system, and such studies should be strongly discouraged.     

QUANTITATIVE HISTOCHEMICAL ANALYSIS OF MAST CELLS AND SENSORY NERVES IN PSORIATIC SKIN

To study the elements of neurogenic inflammation in psoriatic skin, morphological contacts were examined between mast cells and sensory nerves containing the neuropeptides substance P (SP), calcitonin gene-related peptide (CGRP) or vasoactive intestinal polypeptide (VIP). Because mast cells in psoriatic lesions appear in great numbers at the basement membrane (BM) zone, neuropeptide–mast cell contacts with the BM were also counted. A double stain for active mast cell tryptase and the neuropeptides was applied and the contacts were quantitated morphometrically. Sensory nerve–mast cell contacts were also studied three-dimensionally with a confocal laser scanning microscope. Increases in the contact values of SP and CGRP with mast cells, as well as with the BM, were obtained in developing (1–3 weeks) lesions when compared with their non-lesional controls. This increase reached statistical significance in mature lesions. In contrast, the corresponding contact values for VIP were decreased. By confocal microscopy, a close association between mast cells and sensory nerves was observed in the lesional dermis. Since tryptase is known to degrade CGRP but not SP, neurogenic stimuli, mainly via SP, can result in degranulation of mast cells, which release substances to enhance inflammation. At the BM zone in psoriatic lesions, the numerous mast cells loaded with tryptase can promote degradation of BM components and allow entry of various mediators to interact with keratinocytes.     

自噬在肠黏膜屏障功能作用机制的研究进展

自噬是细胞通过膜囊泡结构降解胞质内大分子物质和受损细胞器维持机体稳态的生物学过程。在肠黏膜屏障功能发生障碍过程中,自噬对于维持肠上皮细胞的存活起关键性作用。负调控自噬可导致肠道炎性反应和肿瘤的发生。     

P物质血管活性肠肽和神经肽Y在大鼠舌下腺的免疫组织化学定位

为了解神经肽对舌下腺分泌的功能意义，用免疫组织化学ＡＢＣ法，观察了５只Ｗｉｓｔａｒ大鼠舌下腺内Ｐ物质（ＳＰ）、血管活性肠肽（ＶＩＰ）和神经肽Ｙ（ＮＰＹ）的定位。结果表明，大鼠舌下腺纹状管上皮细胞分别呈ＳＰ、ＶＩＰ和ＮＰＹ免疫反应性，腺泡细胞为阴性。本研究提示，ＳＰ、ＶＩＰ和ＮＰＹ可能参与舌下腺分泌活动和局部血液供应的调节