首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 578 毫秒
1.
何丛  谢川  吕农华 《微生物学报》2014,54(12):1391-1396
幽门螺杆菌(Helicobacter pylori,H.pylori)是一种广泛定植于人胃黏膜的革兰阴性菌,与多种胃部疾病密切相关。近年来H.pylori感染与细胞自噬的关系受到广泛关注,人们发现H.pylori感染影响胃上皮细胞和巨噬细胞的自噬过程,其中H.pylori的毒力因子和宿主自噬相关蛋白发挥关键作用。而且,细胞自噬在决定H.pylori的胞内存活状态中扮演重要角色。本文就H.pylori感染对不同细胞自噬的影响进行综述。  相似文献   

2.
目的研究幽门螺杆菌(H.pylori)与胃黏膜相关淋巴瘤相关性。方法通过胃镜和相关辅助检查,对24例胃黏膜相关淋巴瘤病人胃内幽门螺杆菌进行动态观察。结果24例胃黏膜相关淋巴瘤病人中,18例出现H.pylori感染(75%);治疗后H.pylori感染例数减少(6/24,25%);1年后H.pylori病人感染又增加(11/24,46%)。结论抗H.pylori及胃黏膜相关淋巴瘤常规治疗方法有效,但易反复,可考虑辅以微生态调节剂治疗。  相似文献   

3.
在癌症发生表观遗传学研究中,DNA甲基化是研究最多也最深入的一种机制,异常甲基化可导致胃黏膜上皮细胞癌变.幽门螺杆菌(Helicobacter pylori,Hpylori)是胃癌的第Ⅰ类致癌原,在“慢性浅表性胃炎-慢性萎缩性胃炎-肠上皮化生-不典型增生-胃癌”的癌变模式中可能起先导作用.胃癌相关基因的异常甲基化和H.pylori的致癌机制均是目前研究的热点,本研究综述H.pylori感染与胃黏膜上皮细胞DNA异常甲基化的关系,阐述H.pylori感染介导慢性炎症诱发胃黏膜上皮细胞DNA甲基化的机制.  相似文献   

4.
幽门螺旋杆菌(Helicobacter pylori, H. pylori)选择性地在人的胃黏膜中定植,是引发胃癌的最强危险因素之一。多胺是一类广泛存在于真核细胞中带高密度正电荷的烷基类小分子化合物,参与细胞增殖、分化、凋亡等重要的生理过程,多种疾病的发生发展与多胺代谢紊乱相关。近期研究发现,H.pylori感染能诱导宿主胃黏膜上皮细胞和巨噬细胞中多胺代谢异常。特别是该菌对多胺代谢途径中的关键酶ARG2(arginase 2,精氨酸酶2)、ODC(ornithine decarboxylase,鸟氨酸脱羧酶)和SMO(soermine oxidase,精胺氧化酶)的激活作用,与H. pylori免疫逃逸,慢性炎症维持、DNA损伤和胃癌的发生发展密切相关,提示多胺代谢途径可能成为H. pylori相关胃癌防治的新靶点。  相似文献   

5.
幽门螺旋杆菌(Helicobacter pylori, H. pylori)选择性地在人的胃黏膜中定植,是引发胃癌的最强危险因素之一。多胺是一类广泛存在于真核细胞中带高密度正电荷的烷基类小分子化合物,参与细胞增殖、分化、凋亡等重要的生理过程,多种疾病的发生发展与多胺代谢紊乱相关。近期研究发现,H.pylori感染能诱导宿主胃黏膜上皮细胞和巨噬细胞中多胺代谢异常。特别是该菌对多胺代谢途径中的关键酶ARG2(arginase 2,精氨酸酶2)、ODC(ornithine decarboxylase,鸟氨酸脱羧酶)和SMO(soermine oxidase,精胺氧化酶)的激活作用,与H. pylori免疫逃逸,慢性炎症维持、DNA损伤和胃癌的发生发展密切相关,提示多胺代谢途径可能成为H. pylori相关胃癌防治的新靶点。  相似文献   

6.
幽门螺杆菌(Helicobacter pylori, H. pylori)感染是引起消化系统疾病的主要病因之一,其中以慢性胃炎、胃黏膜相关淋巴组织(mucosa-associated lymphoid tissue lymphoma, MALT)淋巴瘤、胃腺癌为最严重的疾病结局,其致病机制尚不完全清楚。神经肽P物质(substance P, SP)是神经元胞体合成的一种重要的神经肽物质,生物学功能众多,因在宿主免疫应答中作为一种广泛存在的炎症介质而被广为研究。H. pylori感染后可激活神经纤维末梢,引起SP的释放,SP再与多种细胞上受体结合导致不同的细胞炎症因子的释放,SP还可以扰乱正常的信号通路,引起细胞异常增殖。动物实验也证实,SP在促进慢性炎症的发展及癌症的产生中也起作用。本文就SP的相关生物学特性,致病机制及其在H. pylori感染后协同炎症发生等方面的最新进展做一综述,以期为治疗H. pylori相关疾病提供新的思路。  相似文献   

7.
目的研究胃微生物菌群与胃贲门腺癌发病的相关性。方法选择2016年4月-2018年4月在本院就诊的胃贲门腺癌(GCA)患者109例。患者均经病理科组织病理确诊为GCA。对照组为健康人群100例,根据有无H.pylori检出将对照组和GCA组患者分为有H.pylori和无H.pylori感染,其中对照组H.pylori检出19例,未检出81例,GCA组H.pylori检出53例,未检出56例。用胃镜采集贲门胃黏膜,置于无菌冻存管放入液氮中保存,使用16SrRNA的方法进行胃黏膜微生物检测。结果 GCA组患者幽门螺杆菌(H.pylori)感染例数明显高于对照组,无论有无H.pylori感染的对照组人群中,丰度较高的菌属是不动杆菌(Acinetobacter),罗斯氏菌(Rothia),嗜血杆菌(Haemophi-lus),拟杆菌(Bacteroides),链球菌(Streptococcus),韦荣球菌(Veillonella),普氏菌(Prevotella)。无H.pylori组内,GCA组样本中普氏菌(Prevotella)、瓦氏菌(Shewanella)、盐单胞菌(Halomonas)丰度明显高于对照组,有H.pylori组内,GCA组样本中普氏菌(Prevotella)、瓦氏菌(Shewanella)、盐单胞菌(Halomonas)、卟啉单胞菌(Porphyromonas)、梭杆菌(Fusobacterium)丰度明显高于对照组,不动杆菌(Acinetobacter)明显低于对照组。有H.pylori的GCA组样本中普氏菌(Prevotella)、瓦氏菌(Shewanella)、盐单胞菌(Halomonas)、卟啉单胞菌(Porphyromonas)、梭杆菌(Fusobacterium)丰度明显高于无H.pylori的GCA组,不动杆菌(Acinetobacter)明显低于无H.py-lori的GCA组。结果还发现GCA与普氏菌(Prevotella)、瓦氏菌(Shewanella)、盐单胞菌(Halomonas)、卟啉单胞菌(Porphyromonas)、梭杆菌(Fusobacterium)正相关,与不动杆菌(Acineto-bacter)负相关。结论 GCA患者胃内菌群数量和分布与健康人群存在明显差异,H.pylori可能影响胃内菌群结构在GCA发病中发挥作用。  相似文献   

8.
目的对慢性胃炎患者胃黏膜菌群进行定位及定量分析,探究其与胃炎及幽门螺杆菌(Helicobacter pylori,H.pylori)感染的相关性。方法收集58例慢性胃炎患者胃黏膜标本,提取胃黏膜菌群DNA,行荧光定量PCR定量胃黏膜总细菌及H.pylori,并进行相关性分析;另收集12例慢性胃炎患者胃黏膜标本石蜡包埋切片行荧光原位杂交定位胃黏膜菌群;慢性胃炎、肠化生程度的分类依据新悉尼分类系统。结果慢性胃炎患者胃黏膜细菌主要分布于胃黏膜表面、胃小凹及腺体中,细菌单个散在分布或聚集成团。多元线性回归分析显示胃黏膜总细菌数与性别、年龄、肠化生程度无关,与H.pylori感染、慢性胃炎程度有关(P0.05)。H.pylori阳性组胃黏膜总细菌数与H.pylori细菌数目呈明显正相关(r=0.536,P0.01)。不同胃炎程度之间胃黏膜总细菌数差异有统计学意义(P0.05),其中重度胃炎组胃黏膜总细菌数明显高于轻、中度胃炎组(P0.05、0.01)。不同肠化生程度之间胃黏膜总细菌数差异无统计学意义(P0.05)。H.pylori阳性组胃黏膜总细菌数明显高于阴性组(P0.01)。结论慢性胃炎患者胃黏膜菌群主要分布于胃黏膜表面、胃小凹及腺体中,细菌单个散在分布或聚集成团。胃黏膜菌群与慢性胃炎程度、H.pylori感染有关,与性别、年龄、肠化生程度无关,提示胃黏膜菌群的改变参与慢性胃炎的发展,H.pylori感染可改变胃黏膜菌群。  相似文献   

9.
幽门螺杆菌(Helicobacter pylori,H.pylori)是一种革兰阴性杆菌,于1893年首次从慢性活动性胃炎患者的胃黏膜活检组织中被成功分离培养,是目前所知的少数能够在人胃中生存的微生物之一。H.pylori感染不仅可引起胃炎、消化道溃疡、胃黏膜组织相关性(MALT)淋巴瘤等消化系统疾病,其所携带的毒力因子还与胃癌的发生发展有关。不同基因型的H.pylori所携带的毒力因子不同,但只有小部分的感染个体会进展为胃癌的现象。虽然目前诸如CagA、VacA、BabA和OipA等许多毒力因子都已被证明与胃癌的发生有确切关系,但其具体机制仍在进一步的研究当中。本文将主要针对H.pylori中与胃癌相关的毒力因子及其致癌机制进行简要综述,以进一步明确其在胃癌发生发展中的生物学作用。  相似文献   

10.
目的 :建立感染幽门螺杆菌 (Helicobacterpylori,H pylori)SS1株BALB/c小鼠感染模型 ,研究H pylori胃内定植及胃黏膜病理变化。 方法 :BALB/c小鼠胃内分别接种体外培养的H pyloriSS1株 (实验组 )或PBS(对照组 ) ,组织学方法评价H pylori定植及胃黏膜病理变化。结果 :所有对照组小鼠胃组织未见H pylori定植 ,胃组织也未见明显的炎症反应 ;而所有实验组小鼠在感染H pylori 12周后 ,胃黏膜表面的黏液层及胃小凹顶端可见大量H pylori,胃体及胃窦交界处、胃体及胃底交界处最多 ;胃组织可见到不同程度的炎性反应 ,感染H pylori 2 4周后 ,胃组织炎性反应加重。结论 :用胃内接种方法建立了小鼠H pylori感染及其相关性胃炎的模型。  相似文献   

11.
通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.  相似文献   

12.
The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.  相似文献   

13.
14.
龙胆科药用植物化学成分的研究现状   总被引:16,自引:0,他引:16  
龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。  相似文献   

15.
Summary Embryogenic tissues of sugi (Cryptomeria japonica) were induced on a modified Campbell and Durzan (CD) medium containing 1 μM 2,4-dichlorophenoxyacetic acid (2,4-D) and 600 mg l−1 glutamine, and subcultured in the medium of the same composition for over 1 yr. This resulted in a mixed culture of embryogenic and non-embryogenic cells. When embryogenic cells were isolated and cultured independently, their capacity to form embryogenic aggregates was lost. Thus, the non-embryogenic cells present within a mixed culture system were essential to the formation of embryogenic aggregates. When embryogenic tissues were isolated and cultured independently on a high glutamine-containing (2400 mg l−1) medium, dry weights and endogenous levels of glutamine increased, and the tissue could generate a large number of embryogenic aggregates. Amino acid analysis of embryogenic and non-embryogenic cells from the maintenance culture indicated a higher level of glutamine was present in the latter. The high endogenous level of glutamine in the non-embryogenic portion of mixed cell masses may be the supplier of glutamine for maintaining the embryogenic property of the tissues.  相似文献   

16.
The review deals with study of enzymologic properties of a novel highly specific acetylcholinesterase substrate, N-(β-acetoxyethyl) piperidinium iodomethylate (“piperidylcholine”), and its 30 derivatives that were tested as effectors of cholinesterases of mammals and various species of Pacific squids. It was proven for the first time that responsible for specificity of action was structure of cyclic ammonium grouping of the alcohol part of molecule of the ester substrate. Analysis of specificity is performed based on enzymatic hydrolysis parameters—activity of catalytic center of cholinesterases and bimolecular constant of the reaction rate that are determined at optimal and low substrate concentrations. Among the specially synthesized group of thioester compounds there is revealed one more highly specific acetylcholinesterase substrate—N-(β-acetoxyethyl) piperidinium.  相似文献   

17.
18.
真菌类遗传学分析的知识结构教学   总被引:5,自引:2,他引:3  
罗桂花 《遗传》2002,24(3):349-350
本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。 Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching.  相似文献   

19.
目的 针对医疗机构的合理用药水平进行评价研究。方法 根据医疗机构合理用药的具体要求,构建医疗机构合理用药评价指标体系,采用基于模糊群决策的方法和多指标评价分析法构建医疗机构合理用药评价模型。结果 构建了基于模糊群决策的医疗机构合理用药评价模型,并通过实例分析证明了评价模型的可行性。结论 建立的基于模糊群决策的医疗机构合理用药评价模型能够对医疗机构的合理用药水平进行科学评价,为提高医疗机构合理用药水平奠定基础。  相似文献   

20.
Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m−2 s−1. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to Pfr.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号