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101.
为探讨非肾上腺素能非胆碱能神经递质对胃窦环行肌功能的调节作用,在离体胃平滑肌上观察了嘌呤拟似物对胃窦环行肌自发性收缩活动和电活动的影响。电活动用传统的细胞内微电极记录,并和收缩活动同步描记于多道生理记录仪。结果表明,嘌呤能P2Y受体激动剂,三磷酸腺苷(ATP)和2-methylthio ATP(2-MeSATP)均增强胃窦平滑肌的收缩活动,但不影响电活动,而且ATP和2-MeSATP对胃平滑肌收缩活动的增强作用可被嘌呤能P2Y受体阻断剂,reactive blue-2和苏拉明(suramin)所阻断。用100μmol/L α,β-MeATP引起的脱敏感使P2X受体被阻断,ATP增强胃窦平滑肌收缩活动的效应不受影响。嘌呤能P2X受体激动剂,α,β-MeATP明显抑制胃窦环行肌自发性收缩活动,同时使膜电位明显超极化。ATP对胃窦平滑肌的收缩作用不被L型钙通道阻断剂尼卡地平(nicardipine)阻断,但细胞外用无钙液灌流时这种效应则完全被阻断。用前列腺素合成抑制剂消炎痛预先处理20min后,ATP和2-MeSATP仍能增强胃窦平滑肌的自发性收缩活动。以上结果提示:(1)ATP和2-MeSATP通过嘌呤能P2Y受体增强胃窦平滑肌的自发性收缩活动,而α,β-MeATP或β,γ-MeATP通过嘌呤能P2X受体使膜电位超极化,引起胃窦平滑肌的舒张;(2)ATP和2-MeSATP增强胃窦平滑肌自发性收缩活动的效应依赖于细胞外钙,但钙离子进入细胞的途径并不是电压依赖性钙通道;(3)ATP和2-MeSATP增强胃窦平滑肌自发性收缩活动的效应不通过前列腺素介导。 相似文献
102.
The Common Nodulation Genes of Astragalus sinicus Rhizobia Are Conserved despite Chromosomal Diversity 总被引:1,自引:0,他引:1 下载免费PDF全文
Xue-Xian Zhang Sarah L. Turner Xian-Wu Guo Hui-Jun Yang Frdric Debell Guo-Ping Yang Jean Dnari J. Peter W. Young Fu-Di Li 《Applied microbiology》2000,66(7):2988-2995
The nodulation genes of Mesorhizobium sp. (Astragalus sinicus) strain 7653R were cloned by functional complementation of Sinorhizobium meliloti nod mutants. The common nod genes, nodD, nodA, and nodBC, were identified by heterologous hybridization and sequence analysis. The nodA gene was found to be separated from nodBC by approximately 22 kb and was divergently transcribed. The 2.0-kb nodDBC region was amplified by PCR from 24 rhizobial strains nodulating A. sinicus, which represented different chromosomal genotypes and geographic origins. No polymorphism was found in the size of PCR products, suggesting that the separation of nodA from nodBC is a common feature of A. sinicus rhizobia. Sequence analysis of the PCR-amplified nodA gene indicated that seven strains representing different 16S and 23S ribosomal DNA genotypes had identical nodA sequences. These data indicate that, whereas microsymbionts of A. sinicus exhibit chromosomal diversity, their nodulation genes are conserved, supporting the hypothesis of horizontal transfer of nod genes among diverse recipient bacteria. 相似文献
103.
104.
Tianyu Liu Zixuan Guo Xueli Song Li Liu Wenxiao Dong Sinan Wang Mengque Xu Cheng Yang Bangmao Wang Hailong Cao 《Journal of cellular and molecular medicine》2020,24(4):2648-2662
High‐fat diet (HFD) is a well‐known risk factor for gut microbiota dysbiosis and colorectal cancer (CRC). However, evidence relating HFD, gut microbiota and carcinogenesis is limited. Our study aimed to demonstrate that HFD‐induced gut dysbiosis promoted intestinal adenoma‐adenocarcinoma sequence. In clinical study, we found that HFD increased the incidence of advanced colorectal neoplasia (AN). The expression of monocyte chemoattractant protein 1 (MCP‐1), CC chemokine receptor 2 (CCR2) and CD163 in CRC patients with HFD was significantly higher than that in CRC patients with normal diet. When it comes to the Apcmin/+ mice, HFD consumption could induce gut dysbiosis and promote intestinal carcinogenesis, accompanying with activation of MCP‐1/CCR2 axis that recruited and polarized M2 tumour‐associated macrophages. Interestingly, transfer of faecal microbiota from HFD‐fed mice to another batch of Apcmin/+ mice in the absence of HFD could also enhance carcinogenesis without significant body weight gain and induced MCP‐1/CCR2 axis activation. HFD‐induced dysbiosis could also be transmitted. Meanwhile, antibiotics cocktail treatment was sufficient to inhibit HFD‐induced carcinogenesis, indicating the vital role of dysbiosis in cancer development. Conclusively, these data indicated that HFD‐induced dysbiosis accelerated intestinal adenoma‐adenocarcinoma sequence through activation of MCP‐1/CCR2 axis, which would provide new insight into better understanding of the mechanisms and prevention for HFD‐related CRC. 相似文献
105.
杂交水稻及其“三系”线粒体DNA的AP—PCR指纹图谱 总被引:22,自引:1,他引:22
为了研究水稻(Oryza sativa L.)细胞质雄性不育(CMS)与线粒体基因组的关系,应用AP-PCR 分析,用7 个任意单引物对6 种水稻品系线粒体DNA 进行了扩增。水稻线粒体DNA 的AP-PCR 产物可分为三种类型:(1)所有供试品系均能扩增的片段,它们代表了线粒体DNA 在进化上的保守性序列。有4 个引物检测到这类片段。(2)2 个以上水稻品系共同出现而在全部供试材料间存在差异的扩增片段,这类片段是检测水稻线粒体DNA多态性的主要来源。(3)一种细胞质类型所特有的扩增片段,从引物R2 和V5 的扩增产物中发现了这类片段,它们可能与CMS有关联。另外,WA型不育系珍汕97A 与其杂种之间在6 个引物的扩增图谱上均存在不同程度的差异,说明两者的线粒体DNA序列结构可能存在某种差别 相似文献
106.
Heterocyclic ketones as inhibitors of histone deacetylase 总被引:1,自引:0,他引:1
Vasudevan A Ji Z Frey RR Wada CK Steinman D Heyman HR Guo Y Curtin ML Guo J Li J Pease L Glaser KB Marcotte PA Bouska JJ Davidsen SK Michaelides MR 《Bioorganic & medicinal chemistry letters》2003,13(22):3909-3913
Several heterocyclic ketones were investigated as potential inhibitors of histone deacetylase. Nanomolar inhibitors such as 22 and 25 were obtained, the anti-proliferative activity of which were shown to be mediated by HDAC inhibition. 相似文献
107.
108.
我国新分离虫媒病毒的初步鉴定 总被引:2,自引:0,他引:2
1990-1994年,从新疆地区的蚊、蜱和病人血清分离了多株病毒,为了明确这些病毒的分类地位,对其中的20株病毒进行了组织培养细胞感染实验和血清学检验,对部分毒株做了动物接种实验和理化性质鉴定。结果显示:20株病毒均可使BHK-21细胞病变(1-3天),主要表现为细胞圆宿、聚集,融合,破碎,脱落等;致Vero细胞病变为2-4天;15株病毒致C6/36细胞病变(2-4天),5株病毒对C6/36细胞连续观察7天未见细胞病变。11株病毒对乳鼠2-4天致死,对成年鼠2-5天致死。选取6株病毒进行理化性质鉴定,4株病毒(90260、91002、91004和91028)对5-氟脱氧尿苷耐受,对乙醚和酸敏感,提示为有膜RNA病毒;一株病毒(90265)对5-氟脱氧尿苷、乙醚和酸均敏感,提示为有膜DNA病毒;另一株病毒(9059)对5-氟脱氧尿苷耐受,对乙醚和酸也耐受,提示可能为无膜RNA肠道病毒。20株病毒中,17株病毒与甲病毒、乙型脑炎病毒和布尼亚病毒的特异性免疫腹水不反应,提示这些病毒中可能不存在甲病毒、黄病毒和布尼亚病毒;3株病毒(90260、91002和91004)只与甲病毒的特异性免疫腹水反应,与乙型脑炎病毒和布尼亚病毒的不反应,提示这三株病毒为甲病毒。 相似文献
109.
Yi-Rong Guo 《Analytical biochemistry》2009,389(1):32-181
Using a simple test for rapid identification and quantification of pesticide multiresidues in food and environmental samples is a long-cherished approach for practical monitoring purposes. Here two gold-based lateral-flow strips (strip A and strip B) were investigated for simultaneous detection of carbofuran and triazophos. For the strip A format, a bispecific monoclonal antibody (BsMcAb) against both carbofuran and triazophos was employed to prepare the immunogold probe. For the strip B format, anti-carbofuran monoclonal antibody (McAb) and anti-triazophos McAb separately labeled with colloidal gold were combined as detector reagents. By comparison of visual results from pesticide standard tests between the two formats, the strip B assay manifested higher sensitivities for both pesticides. Analysis of spiked water samples by the preferable strip indicated that the detection limits for carbofuran and triazophos were 32 and 4 μg/L, respectively. The strength of the portable one-step strip assay was in the simultaneous screening for two pesticides within a short time (8-10 min) without any equipment. 相似文献
110.
中药山豆根的研究进展 总被引:2,自引:1,他引:2
本文对中药山豆根进行了本草考证,并概括总结了半个世纪以来国内外对山豆根(广豆根)和北豆根在生药学研究、化学成分、药理作用与临床应用等方面的研究成果,为山豆根的进一步研究提供参考。全文附参考文献105篇。 相似文献